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Full-Text Articles in Engineering

Experimental Investigation Of Heat Transfer And Pressure Drop In Copper Manifold Microchannel Heat Sinks, Yue Qiu, Huigang Wang, Jennifer Carter, James Mcguffin-Cawley, Chirag R. Kharangate Jul 2024

Experimental Investigation Of Heat Transfer And Pressure Drop In Copper Manifold Microchannel Heat Sinks, Yue Qiu, Huigang Wang, Jennifer Carter, James Mcguffin-Cawley, Chirag R. Kharangate

Faculty Scholarship

Over the past decade, various two-phase cooling solutions have been implemented to dissipate power in high heat flux electronic components. The manifold microchannel heat sink is an efficient thermal management solution that reduces heat resistance while also limiting the pumping power. However, there is limited work available on small form factor manifold microchannels with traditional heat sinking materials like copper. In this study, an experimental investigation is conducted to evaluate the heat transfer and pressure drop performance of copper manifold microchannel heat sinks using an environmentally friendly refrigerant, R1233zd(E), as the working fluid. A microchannel plate and a manifold plate, …


Examining Driver Injury Severity In Motor Vehicle Crashes: A Copula-Based Approach Considering Temporal Heterogeneity In A Developing Country Context, Shahrior Pervaz, Tanmoy Bhowmik, Naveen Eluru Jul 2024

Examining Driver Injury Severity In Motor Vehicle Crashes: A Copula-Based Approach Considering Temporal Heterogeneity In A Developing Country Context, Shahrior Pervaz, Tanmoy Bhowmik, Naveen Eluru

Civil and Environmental Engineering Faculty Publications and Presentations

Using data from a developing country, the current study develops a copula-based joint modeling framework to study crash type and driver injury severity as two dimensions of the severity process. To be specific, a copula-based multinomial logit model (for crash type) and generalized ordered logit model (for driver severity) is estimated in the study. The data for our analysis is drawn from Bangladesh for the years of 2000 to 2015. Given the presence of multiple years of data, we develop a novel spline variable generation approach that facilitates easy testing of variation in parameters across time in crash type and …


Me-Em Enewsbrief, June 2024, Department Of Mechanical Engineering- Engineering Mechanics, Michigan Technological University Jul 2024

Me-Em Enewsbrief, June 2024, Department Of Mechanical Engineering- Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.


Effect Of Local Chain Stiffness On Oligomer Crystallization From A Melt, Pierre Kawak, Christopher Akiki, Douglas R. Tree Jul 2024

Effect Of Local Chain Stiffness On Oligomer Crystallization From A Melt, Pierre Kawak, Christopher Akiki, Douglas R. Tree

Faculty Publications

While the process by which a polymer crystal nucleates from the melt has been extensively studied via molecular simulation, differences in polymer models and simulated crystallization conditions have led to seemingly contradictory results. We make steps to resolve this controversy by computing low-temperature phase diagrams of oligomer melts using Wang-Landau Monte Carlo simulations. Two qualitatively different crystallization mechanisms are possible depending on the local bending stiffness potential. Polymers with a discrete bending potential crystallize via a single-step mechanism, whereas polymers with a continuous bending potential can crystallize via a two-step mechanism that includes an intermediate nematic phase. Other model differences …


Effect Of Flow Velocity On Clogging Induced By Coal Fines In Saturated Proppant Packs: A Transition From Surface Deposition To Bridging, Fansheng Huang, Fengbin Wang, Shuxun Sang, Shiqi Liu, Zhenjiang You Jul 2024

Effect Of Flow Velocity On Clogging Induced By Coal Fines In Saturated Proppant Packs: A Transition From Surface Deposition To Bridging, Fansheng Huang, Fengbin Wang, Shuxun Sang, Shiqi Liu, Zhenjiang You

Research outputs 2022 to 2026

Hydraulic fracturing is a widely used technique to enhance the production of coalbed methane reservoirs. However, a common issue is the invasion of coal fines into proppant packs, leading to pore clogging and reduced conductivity. This study investigated the impact of flow velocity on clogging by coal fines in saturated proppant packs to optimize the flow velocity and alleviate clogging during dewatering. Clogging experiments induced by coal fines were conducted on saturated proppant packs with varying superficial velocities. Throughout each experiment, the permeability and effluent concentration were monitored, and the process of clogging was visually observed using an optical microscope. …


Data Lakes: A Survey Of Concepts And Architectures, Sarah Azzabi, Zakiya Alfughi, Abdelkader Ouda Jul 2024

Data Lakes: A Survey Of Concepts And Architectures, Sarah Azzabi, Zakiya Alfughi, Abdelkader Ouda

Electrical and Computer Engineering Publications

This paper presents a comprehensive literature review on the evolution of data-lake technology, with a particular focus on data-lake architectures. By systematically examining the existing body of research, we identify and classify the major types of data-lake architectures that have been proposed and implemented over time. The review highlights key trends in the development of data-lake architectures, identifies the primary challenges faced in their implementation, and discusses future directions for research and practice in this rapidly evolving field. We have developed diagrammatic representations to highlight the evolution of various architectures. These diagrams use consistent notations across all architectures to further …


A Model-Based Reverse System Engineering Methodology For Analyzing Complex Biological Systems With A Case Study In Glycolysis, Gerald L. Fudge, Emily Brown Reeves Jul 2024

A Model-Based Reverse System Engineering Methodology For Analyzing Complex Biological Systems With A Case Study In Glycolysis, Gerald L. Fudge, Emily Brown Reeves

Faculty Publications

We propose a model-based reverse systems engineering (MBRSE) methodology for biological systems that relies on requirements analysis in conjunction with model-based systems engineering (MBSE). The goal of this methodology is to better understand complex multiscale biological systems, discover knowledge gaps, and make testable predictions. The similarities between human-engineered and biological systems motivate this approach. Furthermore, traditional reductionist paradigms in biology have proven insufficient for understanding and accurately predicting complex biological systems, as opposed to systems engineering approaches that have proven effective in supporting the design and analysis of complex engineered systems spanning multiple spatiotemporal scales. We employ our MBRSE methodology …


Activity: Students Find Conceptual Errors In Ai Output, Janie Brennan Jul 2024

Activity: Students Find Conceptual Errors In Ai Output, Janie Brennan

Generative AI Teaching Activities

Instructor asks ChatGPT questions related to a key concept to find one where ChatGPT has conceptual errors. Ask students to find the errors and explain them.


Machine Learning Boiling Prediction: From Autonomous Vision Of Flow Visualization Data To Performance Parameter Theoretical Modeling, Cho Ning Huang, Issam Mudawar, Chirag R. Kharangate Jul 2024

Machine Learning Boiling Prediction: From Autonomous Vision Of Flow Visualization Data To Performance Parameter Theoretical Modeling, Cho Ning Huang, Issam Mudawar, Chirag R. Kharangate

Faculty Scholarship

Flow boiling is a highly efficient configuration for meeting the high heat dissipation demands of thermal management systems. However, the complex physics of two-phase flow has hindered its broader application, especially in terms of quantifying visual information. Recent advancements in machine learning vision tools have revolutionized the analysis of phase change phenomena by enabling the digitalization of physically meaningful features such as void fraction, vapor-liquid interfacial behaviors, and liquid-solid wall wetting front areas en masse. In this study, we systematically investigate two-phase models that compute void fractions, heat transfer coefficients, and critical heat flux using live bubble data streams under …


Laser-Induced Electrochemical Biosensor Modified With Graphene-Based Ink For Label-Free Detection Of Alpha-Fetoprotein And 17Β-Estradiol, Ridma Tabassum, Pritu P. Sarkar, Ahmed Hasnain Jalal, Ali Ashraf, Nazmul Islam Jul 2024

Laser-Induced Electrochemical Biosensor Modified With Graphene-Based Ink For Label-Free Detection Of Alpha-Fetoprotein And 17Β-Estradiol, Ridma Tabassum, Pritu P. Sarkar, Ahmed Hasnain Jalal, Ali Ashraf, Nazmul Islam

Mechanical Engineering Faculty Publications

In this research, a novel electrochemical biosensor is proposed based on inducing graphene formation on polyimide substrate via laser engraving. Graphene polyaniline (G-PANI) conductive ink was synthesized by planetary mixing and applied to the working zone of the developed sensor to effectively enhance the electrical signals. The laser-induced graphene (LIG) sensor was used to detect alpha-fetoprotein (AFP) and 17β-Estradiol (E2) in the phosphate buffer saline (PBS) buffer and human serum. The electrochemical performance of the biosensor in determining these biomarkers was investigated by differential pulse voltammetry (DPV) and chronoamperometry (CA). In a buffer environment, alpha-fetoprotein (AFP) and 17β-Estradiol detection range …


Assessment Of Wafer Scale Mos2 Atomic Layers Grown By Metal–Organic Chemical Vapor Deposition Using Organo-Metal, Organo-Sulfide, And H2S Precursors, Michael Curtis, Olivia Moryan, Nicholas Mckibben, Josh Eixenberger, Chen Chen, Karthik Chinnathambi, Sergej Pasko, Salim El Kazzi, Joan M. Redwing, David Estrada Jul 2024

Assessment Of Wafer Scale Mos2 Atomic Layers Grown By Metal–Organic Chemical Vapor Deposition Using Organo-Metal, Organo-Sulfide, And H2S Precursors, Michael Curtis, Olivia Moryan, Nicholas Mckibben, Josh Eixenberger, Chen Chen, Karthik Chinnathambi, Sergej Pasko, Salim El Kazzi, Joan M. Redwing, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

Transition Metal Dichalcogenides (TMDs) are a unique class of materials that exhibit attractive electrical and optical properties which have generated significant interest for applications in microelectronics, optoelectronics, energy storage, and sensing. Considering the potential of these materials to impact such applications, it is crucial to develop a reliable and scalable synthesis process that is compatible with modern industrial manufacturing methods. Metal–organic chemical vapor deposition (MOCVD) offers an ideal solution to produce TMDs, due to its compatibility with large-scale production, precise layer control, and high material purity. Optimization of MOCVD protocols is necessary for effective TMD synthesis and integration into mainstream …


Enterprise Systems: Installing And Configuring Erpnext On Macos, Yazan Abbasi Jul 2024

Enterprise Systems: Installing And Configuring Erpnext On Macos, Yazan Abbasi

Senior Honors Theses

Enterprise Resource Planning (ERP) systems integrate business processes across organizations onto unified digital platforms through data and workflow consolidation. However, high licensing costs of proprietary ERP solutions like SAP and Oracle limit adoption for small and medium enterprises. This led to the emergence of open-source ERP alternatives like ERPNext which provide sophisticated capabilities at much lower total cost of ownership. However, ERPNext faces documentation gaps that hamper onboarding, customization, and widespread adoption. Accelerating ERPNext implementation by developing a comprehensive installation and configuration guide tailored for developers using Mac environments will be examined furthermore.

The background on ERP systems explores critical …


A Case Study On Optimizing Industrial Air Conditioning With Thermal Solar Energy In Egypt, Tamer Adel Mohamed, Hesham Safwat, Mohammed A. Ebaid Jul 2024

A Case Study On Optimizing Industrial Air Conditioning With Thermal Solar Energy In Egypt, Tamer Adel Mohamed, Hesham Safwat, Mohammed A. Ebaid

Mechanical Engineering

This study investigates the feasibility of implementing a solar-assisted adsorption chiller in an industrial building at the Oriental Weavers International factory located in 10th of Ramadan City, Cairo, Egypt. The objective is to replace an inefficient split air conditioning system currently used to cool the Jacquard units during carpet manufacturing. The research begins by analyzing the performance of the existing cooling system to establish a baseline. It then explores the potential energy savings achievable by replacing the current system with a solar-assisted adsorption chiller. The existing oversized boiler will serve as an auxiliary heater for the new system. TRNSYS simulation …


Developing And Testing Low-Cost Air Cleaners For Safer Spaces During Wildfires, Brett W. Stinson, Elliott T. Gall Jul 2024

Developing And Testing Low-Cost Air Cleaners For Safer Spaces During Wildfires, Brett W. Stinson, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Air cleaning reduces indoor exposure to fine particulate matter (PM2.5) during wildfire smoke events. However, resource and cost constraints may limit access to air cleaning during such an event, as both commercial devices and the higher-rated MERV filters that do-it-yourself (DIY) assemblies typically rely upon tend to be expensive and in short supply. With these constraints in mind, we developed and evaluated several configurations of a novel, DIY air cleaner that uses common household fabrics as filtration media. Clean air delivery rates (CADRs) of the devices were experimentally evaluated in two ways: first, with independent measurements of flowrates and single …


Synthesis, Characterization, And Antibacterial Activity Of Graphene Oxide/Zinc Hydroxide Nanocomposites, Jo Ann Sanchez, Luis A. Materon, Jason Parsons, Mataz Alcoutlabi Jul 2024

Synthesis, Characterization, And Antibacterial Activity Of Graphene Oxide/Zinc Hydroxide Nanocomposites, Jo Ann Sanchez, Luis A. Materon, Jason Parsons, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications

Graphene and graphene oxide have shown good antibacterial activity against different bacterial species due to their unique physicochemical properties. Graphene oxide (GO) has been widely used to load metallic and metal oxide nanoparticles (NPs) to minimize their surface energy during processing and preparation, hence reducing their aggregation. In this work, GO was effectively synthesized and coated with different concentrations of zinc hydroxide Zn (OH)x using the precipitation method to prepare a GO/Zn (OH)x hybrid composite. The Zn (OH)x NPs and GO/Zn (OH)x nanocomposites were synthesized and characterized using various methods such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and …


Exploring Co2-Eor Miscibility Flooding Potential For Horus Oil Field, Western Desert, Egypt: A Simulation-Based Investigation, Attia Attia, Adel Salem Prof., Rehab El-Maghraby, Mohamed Youssef Prof. Jul 2024

Exploring Co2-Eor Miscibility Flooding Potential For Horus Oil Field, Western Desert, Egypt: A Simulation-Based Investigation, Attia Attia, Adel Salem Prof., Rehab El-Maghraby, Mohamed Youssef Prof.

Petroleum Engineering and Gas

Carbon dioxide (CO2) miscible flooding is becoming increasingly vital in enhanced oil recovery (EOR) not only for residual oil extraction but also for holding a potential for environmental protection, given its association with global warming. This paper explores the impact of EOR using miscible continuous gas injection on enhancing the oil productivity of the aging Horus oil field in Egypt's Western Desert. Horus field faces declining production rates and a significant water cut, with only eight wells out of 24 wells actively producing. Currently, the field maintains a stabilized oil production plateau of 1050 barrels per day, accompanied by a …


Optoelectronic And Morphological Surface Resistance Evaluation Of Laser-Induced Graphene Counter Electrodes For Potential Applications In Cesium Lead Halide Perovskite Solar Cells, Ziad Khalifa, Sameh Osama Abdellatif, Rami Ghannam Jul 2024

Optoelectronic And Morphological Surface Resistance Evaluation Of Laser-Induced Graphene Counter Electrodes For Potential Applications In Cesium Lead Halide Perovskite Solar Cells, Ziad Khalifa, Sameh Osama Abdellatif, Rami Ghannam

Chemical Engineering

This study investigates the physicochemical, optical, and electrical characterization of laser-induced graphene (LIG) samples for integration as counter electrodes in cesium lead halide perovskite solar cells. The impact of laser processing parameters on electrode performance is explored, including laser power, laser speed, and beam defocus. Density functional theory (DFT) computational modeling is employed for atomistic investigation and work function estimation, demonstrating the density of states (DOS), quantum capacitance of the graphene sheets, and energy work function. NiO is utilized as a hole transport layer, and the energy work function of LIG is tuned accordingly. SEM measurements estimate thin film porosity, …


Direct Evaporative Cooling For Sustainability And Environmental Conservation, Hesham Safwat, Iman El-Mahallawi Jul 2024

Direct Evaporative Cooling For Sustainability And Environmental Conservation, Hesham Safwat, Iman El-Mahallawi

Mechanical Engineering

This work presents the results of experimental work on cellulose cooling pads with honeycomb structure to study their evaporative cooling effect which is one of the partial solutions for achieving the SDG goals 2030. The paper outlines vari ous types of evaporative cooling materials, highlighting their distinctions and potential applications. Furthermore, it offers a comparative analysis of the cooling effects between wide hole and narrow hole cellulose cooling pads, both individually and in combination. The experimental setup results are thoroughly examined to provide insights into the performance of the cooling pads. Results showed up that direct evaporative cooling have a …


Development And Evaluation Of An Expedited System For Creation Of Single Walled Carbon Nanotube Platforms, Ivon Acosta Ramirez, Omer Sadak, Wali Sohail, Xi Huang, Yongfeng Lu, Nicole M. Iverson Jul 2024

Development And Evaluation Of An Expedited System For Creation Of Single Walled Carbon Nanotube Platforms, Ivon Acosta Ramirez, Omer Sadak, Wali Sohail, Xi Huang, Yongfeng Lu, Nicole M. Iverson

Department of Electrical and Computer Engineering: Faculty Publications

Single-walled carbon nanotubes (SWNT) have a strong and stable near-infrared (nIR) fluorescence that can be used to selectively detect target analytes, even at the single molecule level, through changes in either their fluorescence intensity or emission peak wavelength. SWNTs have been employed as NIR optical sensors for detecting a variety of analytes. However, high costs, long fabrication times, and poor distributions limit the current methods for immobilizing SWNT sensors on solid substrates. Recently, our group reported a protocol for SWNT immobilization with high fluorescence yield, longevity, fluorescence distribution, and sensor response, unfortunately this process takes 5 days to complete. Herein …


Introduction To Computer Technology: Build Your Own Computer, Michael Deredita, Orit D. Gruber Jul 2024

Introduction To Computer Technology: Build Your Own Computer, Michael Deredita, Orit D. Gruber

Open Educational Resources

The students will work on a project to specify, shop, and build a desktop computer (using a budget ~ $1,750), according to their needs and applications. Students will use Newegg (https://www.newegg.com) and/or Microcenter (https://www.microcenter.com/) to browse and select (parts), and will record the specifications of the selected components; including the make/model/item number of each part.


Annual Progress In Global Carbon Capture, Utilization, And Storage In 2023, Siyuan Fang, Yun Hang Hu Jul 2024

Annual Progress In Global Carbon Capture, Utilization, And Storage In 2023, Siyuan Fang, Yun Hang Hu

Michigan Tech Publications

Since the industrial revolution, global anthropogenic CO2 emissions have surged dramatically to unsustainable levels, resulting in severe issues, such as global warming, extreme weather events, and species extinction. In response to this critical situation, extensive efforts have been undertaken across academia, industry, and policymaking sectors to deploy carbon capture, utilization, and storage (CCUS) technologies. Here, we present the annual summary of global CCUS for the year 2023. We begin by discussing the trends of anthropogenic CO2 emissions and atmospheric CO2 concentrations, and then offer an up-to-date summary of progress in academia, industry, and policy, respectively. In academia, we analyze the …


Ready, Set, Grow: From Micelles To Giant Vesicles Via Biocatalytic Activation, Nicholas P. Bair, Qinyu Zhu, Bryon A. Staynings, Douglas R. Tree, Walter F. Paxton Jul 2024

Ready, Set, Grow: From Micelles To Giant Vesicles Via Biocatalytic Activation, Nicholas P. Bair, Qinyu Zhu, Bryon A. Staynings, Douglas R. Tree, Walter F. Paxton

Faculty Publications

Controlling physicochemical processes that drive changes in supramolecular aggregates is an important objective toward creating artificial soft micro- and nanomachines. Previous research explored the morphology control of membrane-based materials subjected to externally imposed chemical stimuli. Here, we modulate the microscale morphology of pH-responsive assemblies by using biocatalysis to internally generate changes in global pH. Catalytic reactions offer flexibility in the mechanism and rate at which stimuli are introduced to responsive assemblies, ultimately enabling precision and control over size and morphology. We observed, by dynamic light scattering and fluorescence microscopy, substantial microscale differences between assemblies subjected to manually titrated pH changes …


Experimental Investigations On The Flow Boiling And Heat Transfer Characteristics During Chilldown Process In A Closed Loop Chilldown Test Section, Jayachandran K. Narayanan, Jason W. Hartwig, Mohammad Kassemi, Chirag R. Kharangate Jul 2024

Experimental Investigations On The Flow Boiling And Heat Transfer Characteristics During Chilldown Process In A Closed Loop Chilldown Test Section, Jayachandran K. Narayanan, Jason W. Hartwig, Mohammad Kassemi, Chirag R. Kharangate

Faculty Scholarship

In this study, closed loop chilldown experiments are performed on a 0.009525 m outer diameter SS-316 tube of length 0.6 m and thickness 0.001651 m in a horizontal flow configuration with PF-5060 as the working fluid. The challenges associated with the development of a closed loop chilldown test section in comparison with conventional open loop cryogenic chilldown experiments are discussed and the methods to overcome this are presented. The test section tube is heated to around 246–249 °C to perform the chilldown tests and the film, transition and nucleate boiling regimes along with the single phase liquid convective regimes are …


Blast Wave Simulator For Laminated Glass Panels Experimental Evaluation, Mahmoud T. Nawar, Ayman El-Zohairy, Alaa El-Sisi, Hani Salim Jul 2024

Blast Wave Simulator For Laminated Glass Panels Experimental Evaluation, Mahmoud T. Nawar, Ayman El-Zohairy, Alaa El-Sisi, Hani Salim

Faculty Publications

The study of blast loads on structures is important due to the potential of significant consequences in various scenarios. From terrorist attacks to industrial accidents, comprehending how structures respond to blast waves is critical for ensuring public safety and designing resilient structures. Studying these effects typically involves two main methods: free-field tests with live explosives and shock tube tests. Although shock tube testing offers certain advantages, both approaches are costly and demand significant space. This research aims to develop a cost-effective and straightforward technique for generating stress waves that closely replicate the progressive and spatial characteristics of free-field or shock …


Framework And Methodology For Risk-Based Bridge And Tunnel Asset Management: Objective Risk Assessment And Network Level Evaluation, David Y. Yang, Arash Khosravifar, Diane Moug, Avinash Unnikrishnan Jul 2024

Framework And Methodology For Risk-Based Bridge And Tunnel Asset Management: Objective Risk Assessment And Network Level Evaluation, David Y. Yang, Arash Khosravifar, Diane Moug, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

This report presents the results of the project on establishing a general framework and methodology for risk-based bridge and tunnel asset management. The research was carried out at Portland State University in collaboration with engineers and officials at Oregon Department of Transportation (ODOT) and Federal Highway Administration (FHWA). The primary goal of the research is to achieve risk-based transportation asset management based on (a) objective and consistent risk assessment and (b) effective prioritization and optimization of intervention strategies. Volume I of this report presents methods and findings in the base phase (Phase I) of the project, which is focused on …


Caring: Cannula For Alleviation Of Retinal Injury Caused By Needle Fluidic Gashing, Kaersti L. Rickels, Anthony L. Gunderman, Mattie S. Mclellan, Muhhamad M. Shamim, Joseph A. Sanford, Sami H. Uwaydat Jul 2024

Caring: Cannula For Alleviation Of Retinal Injury Caused By Needle Fluidic Gashing, Kaersti L. Rickels, Anthony L. Gunderman, Mattie S. Mclellan, Muhhamad M. Shamim, Joseph A. Sanford, Sami H. Uwaydat

Mechanical Engineering Faculty Publications and Presentations

Infusion-related iatrogenic retinal breaks (IRBs) are a significant complication in vitrectomies, particularly when smaller-gauge cannulas are used during fluid infusion. Using two-dimensional finite element analysis (FEA), we analyzed forces exerted on the retina from different cannulas: traditional 25-gauge, 20-gauge, 23-gauge, and 27-gauge, then investigated four alternative new cannula designs: (A) oblique orifices, (B) external obstruction, (C) side ports, and (D) perpendicular orifices. The analysis revealed that the standard 25-gauge cannula had a force of 0.546 milli-Newtons (mN). Optimized cannulas demonstrated decreased forces: 0.072 mN (A), 0.266 mN (B), 0.417 mN (C), and 0.117 mN (D). While all the designs decrease …


Examining The Oxidation States Of Metals In Aerosols Emitted By Electronic Cigarettes, Kashala Fabrice Kapiamba, Stephen Yaw Owusu, Yangtao Wu, Yue-Wern Huang, Yi Jiang, Yang Wang Jul 2024

Examining The Oxidation States Of Metals In Aerosols Emitted By Electronic Cigarettes, Kashala Fabrice Kapiamba, Stephen Yaw Owusu, Yangtao Wu, Yue-Wern Huang, Yi Jiang, Yang Wang

Biological Sciences Faculty Research & Creative Works

Electronic cigarettes (ECs) emit many toxic substances, including metals, that can pose a threat to users and the environment. The toxicity of the emitted metals depends on their oxidation states. Hence, this study examines the oxidation states of metals observed in EC aerosols. X-ray photoelectron spectroscopy analysis of the filters that collected EC aerosols identified the oxidation states of five primary metals (based on surface sample analysis), including chromium(III) (close to 100%) under low power setting while a noticeable amount of chromium(VI) (15%) at higher power settings of the EC, and copper(II) (100%), zinc(II) (100%), nickel(II) (100%), lead(II) (65%), and …


Hybrid Mechanism Of Electrical Breakdown In Ferroelectric Materials Under High-Pressure Shock Loading, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Jay B. Chase, Christopher S. Lynch Jul 2024

Hybrid Mechanism Of Electrical Breakdown In Ferroelectric Materials Under High-Pressure Shock Loading, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Jay B. Chase, Christopher S. Lynch

Mining Engineering Faculty Research & Creative Works

The unique ability of ferroelectrics to generate high voltage under shock loading is limited by electrical breakdown within the shock-compressed ferroelectric material. Breakdown is a hybrid process of initiation and growth. The possible mechanisms of electrical breakdown in ferroelectric films and bulk ceramics subjected to high-pressure shock loading are discussed and experiments designed to elucidate which mechanisms govern breakdown. Gigapascal shock loading experiments were performed on poled Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 ferroelectric film specimens in the range of 32-156 μm thickness to determine the dependence of the breakdown field on thickness and …


Finite Element Analysis And Optimization Of The Rotational Stiffness Of Semi-Rigid Base Connection Under Simultaneous Moment And Tension, Mahmoud T. Nawar, Ayman El-Zohairy, Ahmed G. Alaaser, Osman Hamdy Jul 2024

Finite Element Analysis And Optimization Of The Rotational Stiffness Of Semi-Rigid Base Connection Under Simultaneous Moment And Tension, Mahmoud T. Nawar, Ayman El-Zohairy, Ahmed G. Alaaser, Osman Hamdy

Faculty Publications

The base connection is flexible, not fully pinned/fixed, implying a nonlinear moment rotation relationship. This deviates from a linear response, where rotation is not directly proportional to the applied moment. Numerical investigations using the commercial software ABAQUS were conducted to analyze the steel base plate connections. The finite element (FE) models were verified against previous experimental results. Moreover, numerical findings of a comprehensive parametric investigation were conducted. The studied connections were examined with different configurations, including variations in the diameter, spacing, and number of the anchor bolts; the thickness of the base plate; and the applied axial force. The current …


Optimized Gadolinium-Do3a Loading In Raftpolymerized Copolymers For Superior Mr Imaging Of Aging Blood–Brain Barrier, Hunter A. Miller, Aaron Priester, Evan T. Curtis, Krista Hilmas, Ashleigh Abbott, Forrest Kievit, Anthony J. Covertine Jul 2024

Optimized Gadolinium-Do3a Loading In Raftpolymerized Copolymers For Superior Mr Imaging Of Aging Blood–Brain Barrier, Hunter A. Miller, Aaron Priester, Evan T. Curtis, Krista Hilmas, Ashleigh Abbott, Forrest Kievit, Anthony J. Covertine

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The development of gadolinium-based contrast agents (GBCAs) has been pivotal in advancing magnetic resonance imaging (MRI), offering enhanced soft tissue contrast without ionizing radiation exposure. Despite their widespread clinical use, the need for improved GBCAs has led to innovations in ligand chemistry and polymer science. We report a novel approach using methacrylate-functionalized DO3A ligands to synthesize a series of copolymers through direct reversible addition-fragmentation chain transfer (RAFT) polymerization. This technique enables precise control over the gadolinium content within the polymers, circumventing the need for subsequent conjugation and purification steps, and facilitates the addition of other components such as targeting ligands. …