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Articles 22381 - 22410 of 196127

Full-Text Articles in Engineering

Investigating Chloride Ingression In Concrete And Chloride-Induced Rebar Corrosion, Peifeng Su Jan 2024

Investigating Chloride Ingression In Concrete And Chloride-Induced Rebar Corrosion, Peifeng Su

Dissertations, Master's Theses and Master's Reports

The durability of reinforced concrete (RC) structures in chloride-rich environments is compromised due to steel reinforcement corrosion. This dissertation investigates chloride-induced corrosion in concrete containing supplementary cementitious materials (SCMs) and corrosion inhibitors through experimental and numerical methods.

First, the correlations between commonly used parameters and the chloride penetration resistance of concrete were investigated using matrix scatterplot analysis. Concrete samples with various binder types are tested. Results indicate that bulk resistivity is most related to chloride penetration resistance. The effect of SCMs on chloride binding was then studied, and an improved chloride profile prediction model was developed. The binding isotherm of …


Fatigue Resistant Cast Steel Railcar Couplers Produced By Wire-Arc Additive Manufacturing (Waam), Samuel Vellequette Jan 2024

Fatigue Resistant Cast Steel Railcar Couplers Produced By Wire-Arc Additive Manufacturing (Waam), Samuel Vellequette

Dissertations, Master's Theses and Master's Reports

Every year, approximately 90,000 cast steel railcar coupler knuckles are replaced preemptively to avoid fatigue failure. The coupler geometry has been in service since the early 1930s, so geometry changes are restricted to maintain compatibility with the existing fleet. Defects from the casting process, decarburization during heat treatment, and in-service exposure to corrosive environments combine to promote fatigue crack nucleation in high-stress regions of the knuckle. Wire-arc additive manufacturing (WAAM), which uses traditional welding techniques to build material to near-net shapes, was employed to deposit higher-strength materials in critical regions. By replacing the cast steel in the high-stress region of …


Me-Em Enewsbrief, December 2023, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University Jan 2024

Me-Em Enewsbrief, December 2023, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.


Biom 1720: Introduction To Biomedical Engineering Tools, Stephen Strain Jan 2024

Biom 1720: Introduction To Biomedical Engineering Tools, Stephen Strain

Biomedical Engineering Syllabi Archive

Course Description: Use of computer tools for data analysis, presentation, documentation; introduction to programming; individual and group design projects.


Biom 3110: Medical Physiology (Syllabus), Bradford D. Pendley Jan 2024

Biom 3110: Medical Physiology (Syllabus), Bradford D. Pendley

Biomedical Engineering Syllabi Archive

Course Description: Basic principles of human physiology and how these are applied in medicine and biomedical engineering problem and devices; physiological principles using appropriate mathematical and engineering models to construct an understanding of how the body works as an integrated system.


Biom 4784: Biomedical Design Studio (Syllabus), Amy Curry Jan 2024

Biom 4784: Biomedical Design Studio (Syllabus), Amy Curry

Biomedical Engineering Syllabi Archive

Course Description: Laboratory experience dedicated to the design, development, and fabrication of a final prototype for use in conducting engineering analysis and design loop feedback. Responsibilities will include frequent team meetings, mentor advising, and group brainstorming along with prototype designing, technical drawings, fabrication, engineering analysis, and verification/validation. Deliverables for each team will be a prototype, final design specification report with engineering reports, and a final team presentation.


Biom 4410/Mech 4397: Engineering Practicum (Syllabus), Sheila Moses, Jeff Marchetta, Amy Curry Jan 2024

Biom 4410/Mech 4397: Engineering Practicum (Syllabus), Sheila Moses, Jeff Marchetta, Amy Curry

Biomedical Engineering Syllabi Archive

Course Description: Preparation for professional practice through experiential learning under the supervision of an experienced engineer with oversight by a member of the department’s faculty. Regular reporting throughout course required.


Biom 4782: Biomedical Design Practicum (Syllabus), Amy Curry Jan 2024

Biom 4782: Biomedical Design Practicum (Syllabus), Amy Curry

Biomedical Engineering Syllabi Archive

Course Description: Practical application of biomedical design principles with emphasis on project management, teamwork, prototype production, risk analysis and management, technical drawings, patent review with claim development, market analysis, regulatory issues, professional and ethical responsibilities of a biomedical engineer, engineering analysis/reports, incorporation of standards, prototype verification/validation, and presentation skills.


Experimental Evaluation Of Thermal Adaptation And Transient Thermal Comfort In A Tropical Mixed-Mode Ventilation Context, Yue Lei, Duygu Zeynep Tekler, Sicheng Zhan, Clayton Miller, Adrian Chong Jan 2024

Experimental Evaluation Of Thermal Adaptation And Transient Thermal Comfort In A Tropical Mixed-Mode Ventilation Context, Yue Lei, Duygu Zeynep Tekler, Sicheng Zhan, Clayton Miller, Adrian Chong

Research Collection College of Integrative Studies

Mixed-mode ventilation offers a promising solution for achieving comfortable indoor environments in an energy-efficient manner. However, in the tropics, characterized by a year-round hot and humid climate, opportunities for natural ventilation (NV) are typically limited to specific hours, necessitating operational mode switches on an intraday basis. Much of the thermal comfort research on mixed-mode ventilation relies either on cross-sectional data collected from different subjects or longitudinal data spanning a few seasons. This raises an open question: Can occupants thermally adapt when switching between NV and air-conditioning (AC) modes within a single day? To address the gap, our experimental study engaged …


Single-Atom Catalysts For Electrochemical Energy Conversion: Copper Single-Atom Catalyst For Oxygen Reduction Reaction And Quantification Of Site Density By Co Stripping Voltammetry, Dawatage Perera Jan 2024

Single-Atom Catalysts For Electrochemical Energy Conversion: Copper Single-Atom Catalyst For Oxygen Reduction Reaction And Quantification Of Site Density By Co Stripping Voltammetry, Dawatage Perera

Theses and Dissertations--Chemistry

Fuel cells are considered a promising technology for achieving cleaner and more sustainable energy production and utilization. However, one of the current major challenges is the economic viability associated with the extensive use of Pt group metal (PGM) catalysts, particularly on the cathode side. Therefore, non-PGM single-atom catalysts (SACs) have received considerable attention as alternatives for PGM catalysts in the oxygen reduction reaction (ORR), which occurs at the cathode of the fuel cell. Among various SAC structures, the non-PGM/nitrogen-doped carbon-based structure (M-N-C) stands out for its excellent ORR performance.

Chapter 2 illustrates the use of copper metal in place of …


Automation Of Productive Machinery. Bases For An Innovative Business Model, Carlos Guillermo Hernández-Cenzano, Angel Contreras-Cruz, Eduardo Humada-Tello Jan 2024

Automation Of Productive Machinery. Bases For An Innovative Business Model, Carlos Guillermo Hernández-Cenzano, Angel Contreras-Cruz, Eduardo Humada-Tello

Engineering and Technology Management Faculty Publications and Presentations

Nowadays, some laboratories perform elastic properties tests for concrete or rock cores using equipment manufactured 50 years ago. The original data collection procedure uses analog and manual recordings, which can cause inaccuracies in the measurements taken during these trials The process is tedious and updated since each trial's measurement data is recorded manually. In this context, this study systematizes the process and proposes an automated data acquisition and recording system for this type of equipment, followed by a case study presenting a rock compression test.


Design And Analysis Of Coupler Installation Tooling With Computer Vision For Fermilab’S Single Spoke Resonator 2 Srf Cavity, Caleb T. Denton Jan 2024

Design And Analysis Of Coupler Installation Tooling With Computer Vision For Fermilab’S Single Spoke Resonator 2 Srf Cavity, Caleb T. Denton

Graduate Research Theses & Dissertations

Fermi National Laboratory (Fermilab) and the European Council for Nuclear Research (CERN), forerunners in the exploration of the subatomic world, are both in the process of improving their particle accelerators with the Proton Improvement Plan II at Fermilab and the High-Luminosity Large Hadron Collider Accelerator Upgrade Plan (HL-LHC AUP) at CERN. Both particle accelerators have cavities that serve to either accelerate the particle beam or guide it into an optimal position and have the need for radio frequency (RF) power couplers to generate the field that controls the particle beams. When installing the coupler onto the cavity, a reliable vacuum …


Applying Synchrotron Saxs And Xas To Study The Microstructure Of Energy Conversion And Storage Materials, Lingzhe Fang Jan 2024

Applying Synchrotron Saxs And Xas To Study The Microstructure Of Energy Conversion And Storage Materials, Lingzhe Fang

Graduate Research Theses & Dissertations

The microstructure of energy conversion and storage materials is a key determinant of physical properties and electrochemical performance. Synchrotron X-ray techniques, with their strengths of high flux and exceptional brightness, play an irreplaceable role in understanding nano and sub-nano structures. This helps the study of reaction mechanisms and benefits material design in energy conversion and storage area. Electrifying CO2 transformation using renewable energy offers a carbon-neutral solution to CO2 recycling and fuel generation. Among various feedstocks from the CO2 reduction reaction, CO, HCOOH, and CH4 have approached the performance thresholds for industry implementation. The application of single atom catalysts (SACs) …


Evaluating Computational Reproducibility Of Jupyter Notebooks Using Machine Learning And Natural Language Processing, A S M Shahadat Hossain Jan 2024

Evaluating Computational Reproducibility Of Jupyter Notebooks Using Machine Learning And Natural Language Processing, A S M Shahadat Hossain

Graduate Research Theses & Dissertations

In recent years, computational reproducibility, which refers to achieving consistent results upon rerunning an experiment, has become one of the major concerns of various research communities. Jupyter Notebook, as a web-based computational notebook application, offers useful features for running and publishing computational experiments through interactive environments. However, rerunning notebooks does not always reproduce the experimental results. This thesis aims to develop novel methods to evaluate reproducibility by comparing different types of outputs between original and rerun notebooks. It also explores the idea of using machine learning models to predict reproducibility of notebooks automatically without the need of rerunning them. Through …


Modeling And Performance Evaluation Of Traditional And Ai-Based Mppt Techniques For Photovoltaic Systems., Md Badruddaza Jan 2024

Modeling And Performance Evaluation Of Traditional And Ai-Based Mppt Techniques For Photovoltaic Systems., Md Badruddaza

Graduate Research Theses & Dissertations

The efficiency levels to convert from sunlight to electricity are in the range up to 22% commercially, based on the technology used. Due to comparatively low efficiency of photovoltaic systems, it is imperative to extract maximum power from the PV module array. Thus, in solar PV system, tracking the module’s MPP (maximum power point) is crucial and at the same time challenging as well due to varying climatic conditions. This research focuses on the modeling and performance evaluation of traditional Maximum Power Point Tracking (MPPT) techniques and AI-Based MPPT algorithms in photovoltaic systems. It addresses the issue of dynamic adjustment …


Dna I-Motifs: Biophysical Characterization And Structure-Property Correlation As Foundation For Functional Material Design, Alexander Minasyan Jan 2024

Dna I-Motifs: Biophysical Characterization And Structure-Property Correlation As Foundation For Functional Material Design, Alexander Minasyan

Graduate Research Theses & Dissertations

Over the past decades, nucleic acids have emerged as crucial frameworks with significance in biological systems and functional material engineering. Cytosine-rich deoxyribonucleotide sequences can form quadruplex structures a.k.a. i-motifs. Recently, i-motifs have attracted scientific interest in biological and material design areas.

In this work, we systematically investigate an effect of structured and unstructured modifications such as hairpins, stems, loops and overhangs on the kinetic and thermodynamic properties of DNA i-motifs. We demonstrate that the modifications can influence i-motif’s stability and folding/unfolding rates: thus, double stranded stems and hairpins are the best at stabilizing i-motifs and increasing kinetic rates of folding. …


Producing Biocomposites From Hemp Residues, Mohammad Faghani Jan 2024

Producing Biocomposites From Hemp Residues, Mohammad Faghani

Graduate Research Theses & Dissertations

The significant environmental challenges posed by traditional fossil fuel-derived plastics necessitate the exploration of sustainable alternatives. The global production of plastic has dramatically increased from 2 million tons in 1950 to 368 million tons in 2019, with projections exceeding 600 million tons by 2025. By 2040, the greenhouse gas emissions from the lifecycle of these plastics are expected to consume 19% of the global carbon budget. The United States alone produces nearly twice as much plastic waste as China and more than the entire European Union combined, highlighting the urgency of finding eco-friendly solutions.

Biocomposites, combining natural fibers with either …


A One-Wheeled Robot For Exploring Rolling Disk Locomotion, David H. J. Schmidt Jan 2024

A One-Wheeled Robot For Exploring Rolling Disk Locomotion, David H. J. Schmidt

Graduate Research Theses & Dissertations

The work proposed in this thesis is motivated by observations of one-wheel vehicles called monocycles. Whereas the unicycle has the rider sitting on a seat above the wheel, the monocycle’s rider sits inside a large circular hoop that serves as the wheel. Due to the position of the rider inside the wheel, it lowers the overall center of mass of the vehicle below the center of the wheel. For this reason, the uncontrolled longitudinal (forward/backward, or drive axis) dynamics are stable. For modest speeds above a certain threshold, the lateral (side-to-side, or lean axis) dynamics of the monocycle are also …


Bidirectional In-Situ Analysis And Visualization Of Fluid Structure Interactions With Applications In Blood Flow, Nazariy Tishchenko Jan 2024

Bidirectional In-Situ Analysis And Visualization Of Fluid Structure Interactions With Applications In Blood Flow, Nazariy Tishchenko

Graduate Research Theses & Dissertations

Interactive blood flow simulation has applications in the understanding of complex fluids,training medical professionals, diagnostics, and surgical procedure planning. Bidirectional in situ visualization and analysis are much needed to streamline the analysis of large-scale patient-specific blood flow simulations. The in situ component ensures the live visualization of the simulation results while the simulation is running, and the bidirectional component allows for real-time control and configuration of the simulation parameters (i.e., setting and retrieving the simulation parameters and data based on need). In this project, a highly accurate multiphysics simulation was instrumented to work with an existing bidirectional in situ framework. …


Machine Learning For Environmental Sustainability, Syeda Nyma Ferdous Jan 2024

Machine Learning For Environmental Sustainability, Syeda Nyma Ferdous

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research proposes a comprehensive approach to address pressing challenges in environmental sustainability, agricultural residue management, using machine learning based approaches. Machine learning (ML) techniques have emerged as powerful tools for addressing environmental sustainability challenges by facilitating the analysis and prediction of ecological phenomena, and optimization of resource management strategies. The study explores the synergies between environmental sustainability and machine learning to develop a framework that leverages artificial intelligence techniques covering a wide range of tasks including crop residue management, soil CO2 flux prediction, and forest carbon system prediction for sustainable development. The study analyze various ML models, such as, …


Strategies For Process Systems Mapping And Control Based On Operability Analysis, Victor Manuel Cunha Alves Jan 2024

Strategies For Process Systems Mapping And Control Based On Operability Analysis, Victor Manuel Cunha Alves

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation aims to develop strategies for process systems engineering (PSE) mapping using models, emerging tools and algorithms motivated by process operability analysis research. Such strategies will be employed to ensure simultaneous design and control of large-scale industrial systems. The emerging tools and techniques in this research include supervised machine learning-based (ML-based) operability mapping, automatic differentiation (AD) for implicit mapping, and the development of a systematic mapping approach for control structure selection using operability analysis. Thus far, the developed operability algorithms either recur to nonlinear programming (NLP) solutions which are computationally expensive or to linearizing the underlying modeling task at …


Evaluating The Impact Of Ergonomic Interventions On Reducing Knee Musculoskeletal Disorder Risks During Residential Roof Shingle Installation: A Phase-Level Analysis, Nazia Zerin Jan 2024

Evaluating The Impact Of Ergonomic Interventions On Reducing Knee Musculoskeletal Disorder Risks During Residential Roof Shingle Installation: A Phase-Level Analysis, Nazia Zerin

Graduate Theses, Dissertations, and Problem Reports (ETD)

The prevalence of knee musculoskeletal disorders (MSDs) among roofers due to awkward kneeling postures during shingle installation is a well-recognized concern. While knee-saving interventions like knee savers (KSs) and knee pads (KPs) have shown the potential to reduce MSD risks, their effectiveness across different phases of shingle installation remains unknown. The objective of this study is to assess how interventions of KSs and KPs alleviate the risks of MSDs in the knees during various phases of shingle installation. These phases include (1) reaching for shingles, (2) placing shingles, (3) grabbing a nail gun, (4) moving to the first nailing position, …


Machine Learning-Driven Quantification Of Co₂ Plume Dynamics At Ibdp Sites Using Microseismic Data, Ikponmwosa Bright Iyegbekedo Jan 2024

Machine Learning-Driven Quantification Of Co₂ Plume Dynamics At Ibdp Sites Using Microseismic Data, Ikponmwosa Bright Iyegbekedo

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis delves into the utilization of machine learning methodologies to quantify the spatial extent of CO₂ plumes by leveraging microseismic data obtained from the Illinois Basin Decatur Project (IBDP) site spanning November 2011 to June 2018. This initiative, focused on the geological sequestration of carbon dioxide, furnishes a unique and comprehensive dataset comprising well logs, microseismic activity records, and CO₂ injection metrics, all crucial for quantifying the subsurface CO₂ saturation plume dynamics. The primary objective is to forecast the temporal evolution of CO₂ saturation plumes in the subsurface, a critical undertaking for ensuring both the environmental integrity and operational …


The Impact Stress On The Fracture Conductivity And The Productivity Of The Marcellus Shale Horizontal Well, Simon Hanna Menhem Jan 2024

The Impact Stress On The Fracture Conductivity And The Productivity Of The Marcellus Shale Horizontal Well, Simon Hanna Menhem

Graduate Theses, Dissertations, and Problem Reports (ETD)

The increase in effective stress during depletion adversely impacts the productivity of the multi-stage fractured Marcellus shale horizontal well. The geomechanical properties and proppant size influence the degree of shale compaction, the fracture conductivity, and the well productivity. This study seeks to assess the impact of net stress increase during depletion on the productivity of multi-stage fractured Marcellus shale horizontal wells. To investigate the impact of the net stress increase, a model for Bogges-5H well was developed based on the petrophysical and geomechanical properties of the shale obtained from the core plugs and well logs measurements from the pilot (Bogges …


Real-Time Cyber-Power Testbed Enhancement And Synchrophasor Data Generation For Anomaly Detection Using Physics-Informed Machine Learning, Vasavi Sivaramakrishnan Jan 2024

Real-Time Cyber-Power Testbed Enhancement And Synchrophasor Data Generation For Anomaly Detection Using Physics-Informed Machine Learning, Vasavi Sivaramakrishnan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Advanced sensing and automation are essential to managing the evolving electric power system with tight coupling of information and power system layer. However, this increasing number of cyber-physical devices brings vulnerabilities from cyber threats and extreme weather events can endanger the power system on a physical level as well. Advanced monitoring and control algorithms with human operators in the loop are needed to enable power system resiliency despite these increasing threats. These advanced algorithms require validation using a realistic test system that mimics real-world scenarios.

This work focuses on a) developing a realistic real-time cyber-power testbed with hardware-in-the-loop to generate …


Novel Membrane Materials For Nutrient Recovery From Nutrient-Rich Resources, Km Prottoy Shariar Piash Jan 2024

Novel Membrane Materials For Nutrient Recovery From Nutrient-Rich Resources, Km Prottoy Shariar Piash

Graduate Theses, Dissertations, and Problem Reports (ETD)

Global demand for fertilizer production is expanding substantially to meet the food demand of an increasing world population. Anaerobic digestate (AD) of various centralized wastewater facilities contains substantial amounts of ammonium (NH4+) (300-800 mg/L), potassium (K+) (13-120 mg/L), and phosphorus (P) (30-100 mg/L)- based nutrients. In addition to reducing energy costs and CO2 emissions compared to conventional fertilizing raw material manufacturing, recovering nutrients from these waste streams could help mitigate problems such as eutrophication, which otherwise incurs billions of dollars losses to US economy annually. Apart from nutrients, wastewater streams also contain organic pollutants …


Polylactic Acid (Pla) Containing Talc Microparticles And Amorphous Polyhydroxyalkanoates (Aphas) For Improved Barrier And Mechanical Properties In Food Packaging, Mohammed Alfaifi Jan 2024

Polylactic Acid (Pla) Containing Talc Microparticles And Amorphous Polyhydroxyalkanoates (Aphas) For Improved Barrier And Mechanical Properties In Food Packaging, Mohammed Alfaifi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Polylactic acid (PLA) is a biobased and compostable polymer that is increasingly being used as an alternative to petroleum-based, non-biodegradable polymers for single-use food packaging due to its environmental benefits. It is also commercially available in large quantities, and it can be processed like polyethylene. However, it has a higher water-vapor permeability (WVP) as compared to polyolefins and polyethylene terephthalate that are the incumbent materials. This results in a competitive disadvantage in employing PLA for packaging baked goods since the shelf life of the food is likely to be reduced. In the past, barrier properties of PLA were improved by …


Impacts Of Key Degradation Byproducts On Amine Scrubbing For Post-Combustion Carbon Capture, Thomas Jorgensen Jan 2024

Impacts Of Key Degradation Byproducts On Amine Scrubbing For Post-Combustion Carbon Capture, Thomas Jorgensen

Theses and Dissertations--Chemistry

The increasing atmospheric CO2 concentration causes significant concern about global warming and its environmental impact. Industrial sectors, including power generation, transportation, and production factories, contribute most of the anthropogenic sources of CO2 emissions. Researchers search for methods to mitigate these CO2 emissions without compromising the benefits of industrial processes, including CO2 capture, utilization, and sequestration (CCUS). Post-combustion carbon capture (PCCC) by amine scrubbing is the most technology ready CCUS, with various pilot-scale projects worldwide showing small-scale to fully operational plants. While researchers have made significant progress in amine scrubbing, they strive to improve the efficiency and …


Magnetotransport Properties Of Dirac Semimetal Taco2te2 And Ferromagnetic Weyl Semimetal Co3sn2s2, Samuel Pate Jan 2024

Magnetotransport Properties Of Dirac Semimetal Taco2te2 And Ferromagnetic Weyl Semimetal Co3sn2s2, Samuel Pate

Graduate Research Theses & Dissertations

This dissertation investigates the magnetotransport properties of topological semimetals, specifically focusing on the Dirac semimetal TaCo2Te2 and the Weyl semimetal Co3Sn2S2. In TaCo2Te2, I observed extremely large magnetoresistance that violates Kohler’s rule. Extended Kohler’s rule can be applied with a calculation of Hall factor at low temperatures. I also explored the applicability of the two-band and four-band models of carrier analysis and correlate the region where Kohler’s rule is obeyed to the four-band model. In Co3Sn2S2, I explored the angle-dependent anomalous Hall effect (AHE) near the Kagome plane, revealing a tunable AHE under applied fields and an abrupt disappearance of …


First Course Portfolio For Tmfd 213: Merchandising I: Textile And Apparel Industry, Na Young Jung Jan 2024

First Course Portfolio For Tmfd 213: Merchandising I: Textile And Apparel Industry, Na Young Jung

UNL Faculty Course Portfolios

This portfolio presents a comprehensive overview of TMFD 213: Merchandising I, a foundational course in the Department of Textiles, Merchandising, and Fashion Design at the University of Nebraska-Lincoln. The course is designed to equip students with critical thinking, analytical skills, and industry-specific knowledge necessary for professional success in the textile and apparel industry. The portfolio outlines the course’s objectives, teaching methodologies, and the impact of instructional strategies on student learning outcomes. It includes detailed analyses of quantitative and qualitative data collected through pre- and post-test surveys, assignments, and reflections. Quantitative results demonstrate significant improvements in key areas such as familiarity …