Engineering Commons^™

Z-Source-Based High Step-Up Dc-Dc Converters For Photovoltaic Applications, Ramin Rahimi, Saeed Habibi, Mehdi Ferdowsi, Pourya Shamsi

Electrical and Computer Engineering Faculty Research & Creative Works

This article proposes three high step-up Z-source (ZS)-based dc-dc converters by integrating the conventional ZS network with switched-capacitor (SC) cells. The proposed converters offer a simple structure with a smooth input current, a high-voltage gain, and low voltage stress on the semiconductor devices. In addition, the proposed converters, unlike some existing ZS-based topologies in the literature, do not impose any limitation on the duty cycle of the power switch. These characteristics make the proposed converters excellent candidates to interface a low-voltage solar photovoltaic (PV) panel with a high-voltage dc bus in PV applications. Among the proposed three converters, the operating …

On The Sensitivity Of Microwave Fabry-Perot Interferometers For Displacement Detection, Chen Zhu, Rex E. Gerald, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Microwave Interferometers Have Been Attractive Devices for High-Precision Measurements of Displacement-Related Physical Quantities in a Variety of Scientific and Engineering Applications. However, Due to the Long Operating Wavelength, the Displacement Measurement Resolution of Microwave Interferometers is Limited to the Micrometer Scale. in This Article, We Propose and Demonstrate a Novel Technology based on Microwave Interferometry for Displacement Measurements with Potential Picometer Resolution. an Open-Ended (OE) Transmission Line Resonator based on a Homemade Hollow Coaxial Cable is Explored in Proof-Of-Concept Numerical and Experimental Investigations. the Technique Involves Two Stages of Displacement Sensitivity Amplification: One is the Open End-Based Phase Sensitivity Amplification, …

Replacing Combustion Engines With Hydrogen Fuel Cells To Power Mining Haul Trucks: Challenges And Opportunities, Ayorinde Akinrinlola

Masters Theses

"With the proven advantage of higher energy density in hydrogen fuel cells over batteries, there is potential to apply fuel cells to power mining haul trucks. This study aims to evaluate the technical and economic feasibility of hydrogen fuel cell electric mine trucks as an alternative to current mine haul trucks. Specifically, the project: (1) developed an economic framework for evaluating the integration of renewable energy powered haul trucks into mining; and (2) applied vehicle drivetrain and energy simulation in Matlab/Simulink to elucidate the challenges and opportunities of incorporating hydrogen fuel cell technology into the current form factors of mine …

Modeling The Reactor Time-Dependent Delayed Particle Tail With Monte Carlo N-Particle (Mcnp) Version 6.2, Eli James Boland

Masters Theses

"Energy is deposited into experiment packages due to post-shutdown decay heat created from delayed particles. Modeling these delayed particles in a reactor assists researchers in quantifying the expected energy deposition sources to an experiment package before irradiation. This paper focuses on modeling the delayed particles in a reactor in MCNP6.2 by capturing a reactor as a source, converting this source capture to a source definition, applying appropriate physics such as activation and photonuclear interactions, and finally using proper tallies to create the expected delayed particle tail of a reactor.

To capture the source distribution, the FMESH capability within MCNP was …

Personalizing Student Graduation Paths Using Expressed Student Interests, Nicolas Charles Dobbins

Masters Theses

"This work proposes an intelligent recommender approach to facilitate personalized education and help students in planning their path to graduation. The original research contribution of this work is to develop a recommender approach that pervasively personalizes and optimizes a student’s path to graduation by accounting for the student’s career interests and academic background. The approach is a multi-objective optimization problem, subject to institutional constraints, with the goal of optimizing the graduation path with respect to one or more criteria, such as time-to-graduation, credit hours taken, and alignment with student’s career interests. The efficacy of the approach is illustrated and verified …

Understanding Charge Effects On Marked Ball Wear Rates – A Corrosion Study, John Bailey Fletcher

Masters Theses

"To measure the wear rates of grinding balls within a ball mill, marked ball wear tests (MBWTs) have been used extensively. Using the wear rates from a MBWT, operators select the most cost-effective media for their grinding application. One factor that a MBWT does not account for is the possible interaction between different media materials which could affect their corrosion rates. Galvanic coupling between dissimilar metals can cause significant changes in their corrosion rates. While galvanic interactions between minerals and grinding media have been studied, the interaction between dissimilar media has not. Corrosion rates and potentials of modern high carbon …

Effect Of Boron In Cast Iron, Suyash Durendra Pawaskar

Masters Theses

"Boron, mostly considered a residual element, has started to cause issues in the cast iron foundries by causing a decrease in the strength of pearlitic gray and ductile iron castings. Because of the increase in the use of boron-added steel scrap from automotive steel and a lack of agreement on the critical levels of boron in cast iron, foundries are facing difficulties in controlling the microstructure of gray iron castings when boron is present. The current investigation was designed to analyze the effects of boron in cast irons and predict a mechanism to understand its effects with a vision of …

Advanced Topologies Of High Step-Up Dc-Dc Converters For Renewable Energy Applications, Ramin Rahimi

Doctoral Dissertations

"This research is focused on developing several advanced topologies of high step-up DC-DC converters to connect low-voltage renewable energy (RE) sources, such as photovoltaic (PV) panels and fuel cells (FCs), into a high-voltage DC bus in renewable energy applications. The proposed converters are based on the combinations of various voltage-boosting (VB) techniques, including interleaved and quadratic structures, switched-capacitor (SC)-based voltage multiplier (VM) cells, and magnetically coupled inductor (CI) and built-in-transformer (BIT). The proposed converters offer outstanding features, including high voltage gain with low or medium duty cycle, a small number of components, low current and voltage stresses on the components, …

Shape Memory Alloys Via Halide-Activated Pack Equilibration, Andrew S. King, Ryan D. Dempsey, David W. Lipke

Materials Science and Engineering Faculty Research & Creative Works

Fabrication of shape memory alloy (SMA) components based on NiTi is challenging due to the precision with which elemental composition and microstructure must be controlled during processing to achieve desired shape memory behavior. Herein, a method to control chemistry in an NiTi SMA via halide-activated pack equilibration (SHAPE) against a constant chemical potential reservoir is described. To demonstrate the efficacy of the SHAPE process, an initially titanium-deficient specimen (pure nickel foam) has been equilibrated against an excess of an intimately mixed two-phase pack (NiTi + Ti2Ni) in the presence of a vapor phase transport agent (iodine). The two-phase pack regulates …

Studies Of Multiphase Distribution And Flow In Bubble/ Slurry Bubble Columns With /Without Internals And Advanced Sustainable Construction Materials Using Sophisticated Measurement Techniques, Omar Farid

Doctoral Dissertations

"Bubble/slurry bubble columns have been widely studied and employed as multiphase flow reactors with and without vertical heat-exchanging tubes. In order to understand more deeply the effect of the dense internals on the hydrodynamics of bubble/slurry bubble column, systematic experiments were performed to visualize and quantify using the radioactive particle tracking (RPT) technique. A new methodology for implementing the radioactive particle tracking (RPT) technique has been developed to investigate the effect of the dense internals on the hydrodynamics of the bubble/slurry column reactor. Monte Carlo N-Particle (MCNP) simulation has been implemented to simulate the system to generate a large number …

Development Of Flood Prediction Models Using Machine Learning Techniques, Bhanu Kanwar

Doctoral Dissertations

"Flooding and flash flooding events damage infrastructure elements and pose a significant threat to the safety of the people residing in susceptible regions. There are some methods that government authorities rely on to assist in predicting these events in advance to provide warning, but such methodologies have not kept pace with modern machine learning. To leverage these algorithms, new models must be developed to efficiently capture the relationships among the variables that influence these events in a given region. These models can be used by emergency management personnel to develop more robust flood management plans for susceptible areas. The research …

Fully Kinetic Particle-In-Cell Simulations Of Plasma-Surface-Dust Interactions For Lunar Exploration, Jianxun Zhao

Doctoral Dissertations

"The studies involving lunar surface explorations have drawn attentions in recent years. A better understanding of possible potential hazards to astronauts and electronic equipment has become a necessity for future lunar explorations. The lunar surface, lacking an atmosphere and global magnetic field therefore directly exposed to solar radiation and solar wind plasma, is electrically charged by the bombardment of solar wind plasma and emission/collection of photoelectrons. Additionally, lunar dust grains can also get charged and levitated from the surface under the influence of the electric field as well as gravity within the plasma sheath. Since the plasma sheath formed near …

Machine Learning Applications In Plant Identification, Wireless Channel Estimation, And Gain Estimation For Multi-User Software-Defined Radio, Viraj K. Gajjar

Doctoral Dissertations

"This work applies machine learning (ML) techniques to selected computer vision and digital communication problems. Machine learning algorithms can be trained to perform a specific task without explicit programming. This research applies ML to the problems of: plant identification from images of leaves, channel state information (CSI) estimation for wireless multiple-input-multiple-output (MIMO) systems, and gain estimation for a multi-user software-defined radio (SDR) application.

In the first task, two methods for plant species identification from leaf images are developed. One of the methods uses hand-crafted features extracted from leaf images to train a support vector machine classifier. The other method combines …

Evaluating Barriers To And Impacts Of Rural Broadband Access, Javier Valentín-Sívico

Doctoral Dissertations

"The lack of adequate broadband infrastructure persists in many rural communities. Beyond funding, additional barriers persist, such as digital literacy and community-level self-efficacy. As a result, the first contribution articulates barriers at the organizational level. This work proposes a framework based on the Theory of Planned Behavior to highlight stakeholder dynamics that have constrained Regional Planning Commissions from advancing broadband infrastructure in rural areas. One approach to address these barriers is to provide stakeholders with analytical tools to evaluate the benefits and costs of various broadband options for their community since there is not a one-size-fits-all solution. To this end, …

Wind Flow Characteristics Of Multi-Vortex Tornadoes And Their Wind Effects On Residential Houses, Yi Zhao

Doctoral Dissertations

"Tornadoes strike the USA very frequently, with an average of 1200 reports per year, and the average annual tornado-induced property loss has reached $10B. The devastation from recent tornadoes have prompted a renewed interest in better understanding tornado dynamics, their interactions with the built environment, and the performance of civil structures during tornadoes. In the past, the wind effects caused by single-vortex tornadoes have been widely studied, while the multi-vortex tornadoes were rarely considered. In fact, many previous deadly, costly tornadoes involved multiple vortices. Therefore, it is important to understand the wind flow characteristics of multi-vortex tornadoes in order to …

High-Performance Catalytic Four-Channel Hollow Fibers With Highly Dispersed Nickel Nanoparticles Prepared By Atomic Layer Deposition For Dry Reforming Of Methane, Baitang Jin, Shiguang Li, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Highly dispersed nickel (Ni) nanoparticles (NPs) with an average particle size of 4.3 nm were uniformly deposited on the outer surface, the inner channel surface, and inside the pores of 20 cm long four-channel α-Al₂O₃hollow fibers (HFs) by atomic layer deposition (ALD) for dry reforming of methane (DRM). Cerium oxide (CeO₂) was added to promote the catalytic performance of Ni/Al₂O₃-HF catalysts. Rationally designed filling methods, by tuning the reactor size and inert fillings, can reduce the catalyst bed voidage in a fixed bed reactor for better reactant gas distribution, effectively …

Ds-Menet For The Classification Of Citrus Disease, Xuyao Liu, Yaowen Hu, Guoxiong Zhou, Weiwei Cai, Mingfang He, Jialei Zhan, Yahui Hu, Liujun Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Affected by various environmental factors, citrus will frequently suffer from diseases during the growth process, which has brought huge obstacles to the development of agriculture. This paper proposes a new method for identifying and classifying citrus diseases. Firstly, this paper designs an image enhancement method based on the MSRCR algorithm and homomorphic filtering algorithm optimized by Laplacian (HFLF-MS) to highlight the disease characteristics of citrus. Secondly, we designed a new neural network DS-MENet based on the DenseNet-121 backbone structure. In DS-MENet, the regular convolution in Dense Block is replaced with depthwise separable convolution, which reduces the network parameters. The ReMish …

Ds-Menet For The Classification Of Citrus Disease, Xuyao Liu, Yaowen Hu, Guoxiong Zhou, Weiwei Cai, Mingfang He, Jialei Zhan, Yahui Hu, Liujun Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Affected by various environmental factors, citrus will frequently suffer from diseases during the growth process, which has brought huge obstacles to the development of agriculture. This paper proposes a new method for identifying and classifying citrus diseases. Firstly, this paper designs an image enhancement method based on the MSRCR algorithm and homomorphic filtering algorithm optimized by Laplacian (HFLF-MS) to highlight the disease characteristics of citrus. Secondly, we designed a new neural network DS-MENet based on the DenseNet-121 backbone structure. In DS-MENet, the regular convolution in Dense Block is replaced with depthwise separable convolution, which reduces the network parameters. The ReMish …

Commercial Janus Fabrics As Reusable Facemask Materials: A Balance Of Water Repellency, Filtration Efficiency, Breathability, And Reusability, Steven Cheng, Weixing Hao, Yuchen Wang, Yang Wang, Shu Yang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Facemasks as personal protective equipment play a significant role in helping prevent the spread of viruses during the COVID-19 pandemic. A desired reusable fabric facemask should strike a balance of water repellency, good filtration efficiency (FE), breathability, and mechanical robustness against washing cycles. Despite significant efforts in testing various commercial fabric materials for filtration efficiency, few have investigated fabric performance as a function of the fiber/yarn morphology and wettability of the fabric itself. In this study, we examine commercial fabrics with Janus-like behaviors to determine the best reusable fabric facemask materials by understanding the roles of morphology, porosity, and wettability …

Impact Of Ultrathin Coating Layer On Lithium-Ion Intercalation Into Particles For Lithium-Ion Batteries, Yufang He, Hiep Pham, Xinhua Liang, Jonghyun Park

Chemical and Biochemical Engineering Faculty Research & Creative Works

Ultrathin film coatings on battery materials via atomic layer deposition (ALD) have been demonstrated as an efficient technology for battery performance enhancement. However, the fundamental understanding on lithium intercalation into active materials through the interface between the coating and active materials is unclear, which makes it difficult to optimize ALD coating strategies. Further, like most active materials, a coating layer can undergo volume change during the intercalation process, which can produce detrimental structural changes and mechanical failure of the layer. In this work, first-principles calculations are conducted to reveal the behavior of a coating layer on an active material particle …

Aryl Sulfonic Acid Catalysts: Effect Of Pendant Group Structure On Activity In Hydrolysis Of Polyethylene Terephthalate, Hossein Abedsoltan, Maria R. Coleman

Chemical and Biochemical Engineering Faculty Research & Creative Works

A series of aryl sulfonic acids were tested as catalysts for acid hydrolysis occurring at the surface of poly(ethylene) terephthalate (PET) particles. Specifically, p-toluene sulfonic acid monohydrate (PTSA), 2-naphthalenesulfonic acid (2-NSA), and 1,5-naphthalenedisulfonic acid tetrahydrate (1,5-NDSA) were chosen to provide sulfonic acid active groups and varying hydrophobic functionality. The effect of catalyst concentration and reaction temperature on PET hydrolysis rate was studied. The aryl sulfonic acid catalysts exhibited much higher rates of PET hydrolysis than the mineral acid, H₂SO₄. At 150°C and 4 M catalyst, the time required to achieve more than 90% TPA yield was …

A Comparative Study On Representativeness And Stochastic Efficacy Of Miniature Tensile Specimen Testing, Sreekar Karnati, Sriram Praneeth Isanaka, Yunlu Zhang, Frank W. Liou, Jason L. Schulthess

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this article, a miniature dog bone tensile coupon design was tested against the existing ASTM standard specimen design. Specimens were prepared from commercially sourced austenitic stainless steel 304 alloy, and a defect-ridden additively manufactured 304L alloy was studied. By utilizing a tensile specimen design that is 1/230th volume of the smallest ASTM E8-04 (2016), Standard Test Methods for Tension Testing of Metallic Materials, dog bone specimen, coupled to a digital image correlation (DIC) setup, case studies were performed to compare tensile property measurements and strain field evolution. Whereas yield strength measurements were observed to be similar, post-yield, the ultimate …

Mdam-Drnet: Dual Channel Residual Network With Multi-Directional Attention Mechanism In Strawberry Leaf Diseases Detection, Tingjing Liao, Ruoli Yang, Peirui Zhao, Wenhua Zhou, Mingfang He, Liujun Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The growth of strawberry plants is affected by a variety of strawberry leaf diseases. Yet, due to the complexity of these diseases' spots in terms of color and texture, their manual identification requires much time and energy. Developing a more efficient identification method could be imperative for improving the yield and quality of strawberry crops. To that end, here we proposed a detection framework for strawberry leaf diseases based on a dual-channel residual network with a multi-directional attention mechanism (MDAM-DRNet). (1) In order to fully extract the color features from images of diseased strawberry leaves, this paper constructed a color …

Mdam-Drnet: Dual Channel Residual Network With Multi-Directional Attention Mechanism In Strawberry Leaf Diseases Detection, Tingjing Liao, Ruoli Yang, Peirui Zhao, Wenhua Zhou, Mingfang He, Liujun Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The growth of strawberry plants is affected by a variety of strawberry leaf diseases. Yet, due to the complexity of these diseases' spots in terms of color and texture, their manual identification requires much time and energy. Developing a more efficient identification method could be imperative for improving the yield and quality of strawberry crops. To that end, here we proposed a detection framework for strawberry leaf diseases based on a dual-channel residual network with a multi-directional attention mechanism (MDAM-DRNet). (1) In order to fully extract the color features from images of diseased strawberry leaves, this paper constructed a color …

Analysis Of Sequential Adsorption-Oxidation Of Vocs On Atomic Layer-Deposited Ptni/Zro2-Sio2dual-Function Materials, Busuyi O. Adebayo, Han Yu, Ali A. Rownaghi, Xinhua Liang, Fateme Rezaei

Chemical and Biochemical Engineering Faculty Research & Creative Works

To develop efficient dual-function materials (DFMs) for capture and destruction of volatile organic compounds (VOCs), we prepared a series of composite materials comprising PtNi nanoparticles supported on ZrO₂-promoted SiO₂(PtNi/ZrO₂-SiO₂) via atomic layer deposition (ALD) method and investigated them for sequential adsorption and desorption/catalytic oxidation of benzene, as a model VOC compound. ZrO₂was first deposited on a unimodal SiO₂support, followed by deposition of Pt and Ni nanoparticles with varried amount. Dynamic adsorption experiments were conducted using a 500 ppmv-laden feed at 25 °C and 1 atm, followed by in …

Machine Learning Boosts Performance Of Optical Fiber Sensors: A Case Study For Vector Bending Sensing, Chen Zhu, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

The Spectral Response Produced When a High-Sensitivity Optical Fiber Sensor (OFS) is Subject to an External Perturbation Has Recently Been Shown to Contain Rich Information that Can Be Potentially Exploited for Multi-Dimensional Sensing. in This Article, We Propose the Use of Machine Learning to Directly and Statistically Learn the Relation between the Complex Spectral Response from an OFS and a Measurand of Interest, Without Knowing If There Are Distinct and Tractable Features in the Spectrum. as a Proof-Of-Concept Demonstration, It is Shown that a Simple Heterostructure-Based Device with a Capillary Tube Sandwiched between Two Single-Mode Fibers Without Any Fiber Modification …

Life Cycle Cost Analysis Of High Friction Surface Treatment Applications, Eslam Deef-Allah, Korrenn Broaddus, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Life cycle cost analyses for high friction surface treatment (HFST) applications were executed relying on a Microsoft Excel program developed by the researchers. Calcined bauxite (CB), five CB alternatives, and epoxy binder were utilized in the HFST applications. The aggregates' performances were evaluated through the aggregate image measurement system (AIMS) before and after Micro-Deval polishing. The performance of the HFST applications was evaluated by the dynamic friction tester (DFT) and British pendulum (BP). The major purpose of this program was to present a rational method for converting different input data (project and material specifics) to comparable output data (net present …

Quantification Of The State Of Practice Of Offsite Construction And Related Technologies: Current Trends And Future Prospects, Rayan H. Assaad, Islam H. El-Adaway, Makarand Hastak, Kim Lascola Needy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Although some researchers and practitioners have perceived that the current reliance on offsite construction methods is high, other studies have hypothesized that the use of offsite construction techniques is still considered to be somehow limited. To this end, this paper aims to quantify the state of practice of offsite construction in terms of current trends and future prospects for the overall industry as well as the following main sectors: industrial, building and commercial, and infrastructure. First, a questionnaire was formed, pilot-tested, distributed, and completed by 100 construction practitioners. Second, the questionnaire's internal and external validity and reliability were examined using …

The Impact Of Offsite Construction On The Workforce: Required Skillset And Prioritization Of Training Needs, Rayan H. Assaad, Islam H. El-Adaway, Makarand Hastak, Kim Lascola Needy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Offsite construction has showed great potential in addressing many of the industry's problems. While multiple research efforts have been directed at examining different offsite construction aspects, few studies investigated the workforce-related aspects. Therefore, this study aims to address this knowledge gap by examining the impact of offsite construction on the workforce, as represented by the following five workforce categories: offsite, onsite, engineering and design, construction and fabrication, and administrative workforce. To this end, this paper (1) determined the impact of offsite construction on the skillset (reskilling or upskilling) and the demand (shrink or growth) for the offsite and onsite construction …

Metastable Olivine Within Oceanic Lithosphere In The Uppermost Lower Mantle Beneath The Eastern United States, Fansheng Kong, Stephen S. Gao, Kelly H. Liu, Yinxia Fang, Hejun Zhu, Robert J. Stern, Jiabiao Li

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Approximately two-thirds of Earth's outermost shell is composed of oceanic plates that form at spreading ridges and recycle back to Earth's interior in subduction zones. A series of physical and chemical changes occur in the subducting lithospheric slab as the temperature and pressure increase with depth. In particular, olivine, the most abundant mineral in the upper mantle, progressively transforms to its high-pressure polymorphs near the mantle transition zone, which is bounded by the 410 km and 660 km discontinuities. However, whether olivine still exists in the core of slabs once they penetrate the 660 km discontinuity remains debated. Based on …