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Articles 121 - 150 of 2083

Full-Text Articles in Engineering

Contribution Of Implicit Memory To Adaptation Of Movement Extent During Reaching Against Unpredictable Spring-Like Loads: Insensitivity To Intentional Suppression Of Kinematic Performance, Devon D. Lantagne, Leigh A. Mrotek, James B. Hoelzle, Danny G. Thomas, Robert A. Scheidt Sep 2023

Contribution Of Implicit Memory To Adaptation Of Movement Extent During Reaching Against Unpredictable Spring-Like Loads: Insensitivity To Intentional Suppression Of Kinematic Performance, Devon D. Lantagne, Leigh A. Mrotek, James B. Hoelzle, Danny G. Thomas, Robert A. Scheidt

Psychology Faculty Research and Publications

We examined the extent to which intentionally underperforming a goal-directed reaching task impacts how memories of recent performance contribute to sensorimotor adaptation. Healthy human subjects performed computerized cognition testing and an assessment of sensorimotor adaptation, wherein they grasped the handle of a horizontal planar robot while making goal-directed out-and-back reaching movements. The robot exerted forces that resisted hand motion with a spring-like load that changed unpredictably between movements. The robotic test assessed how implicit and explicit memories of sensorimotor performance contribute to the compensation for the unpredictable changes in the hand-held load. After each movement, subjects were to recall and …

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Evaluation Of Amnion Membrane Made Vascular Graft In Rat Model And Porcine Model, Xiaolong Wang Jul 2023

Evaluation Of Amnion Membrane Made Vascular Graft In Rat Model And Porcine Model, Xiaolong Wang

Master's Theses (2009 -)

Heart bypass surgery has become a common therapeutic strategy to save heart attack patients from death. However, there are issues with the availability of graft resources for patients who cannot use autologous vessels due to their health conditions. To solve this problem, this study aims to develop a small-diameter vascular graft based on the human decellularized amniotic membrane (DAM) as an alternative to autologous vessels. The human amniotic membrane was harvested from the placenta, obtained from consenting and de-identified donors, and decellularized to remove cellular components while preserving its extracellular matrix. Small-diameter vascular grafts were fabricated using the DAM as …

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Creep Resistance And Microstructure In Binary Aluminum Cerium Alloy Produced By Laser Powder Bed Fusion, Jillian Ann Stinehart Jul 2023

Creep Resistance And Microstructure In Binary Aluminum Cerium Alloy Produced By Laser Powder Bed Fusion, Jillian Ann Stinehart

Master's Theses (2009 -)

Currently, the only commercially available aluminum alloy for additive manufacturing (AM) is AlSi10Mg, which is not suitable for high temperature applications. Al-Ce based alloys have been shown to be highly printable, cost-efficient alloys. Compared to cast Al-Ce alloys, the eutectic features are refined (<1μm), which give AM Al-10Ce favorable strength and ductility at room temperature. The low diffusivity and solubility of cerium in aluminum improve the retention of mechanical properties at high temperatures. In order to quantify the effect of cerium on the thermal stability of AM aluminum and show its suitability for high-temperature applications, Al-10Ce was creep tested between 60-77% of its absolute melting temperature. The creep performance of AM Al-10Ce was favorable compared to that of cast binary Al-Ce and AM AlSi10Mg and was comparable to that of cast ternary Al-Ce alloys. The stress exponent, n, was approximately 1 in the low stress regime and 5-7 in the high stress regime. The activation energy was 231kJ/mol. In comparison, both cast binary Al-Ce and AM AlSi10Mg have higher stress exponents and lower activation energies, showing AM Al-10Ce to be more creep resistant. After creep testing, slight grain coarsening was observed, while grain orientation remained unchanged. The melt pool boundaries (MPBs) faded in appearance after creep testing, and the number of columnar grains decreased.

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Dynamic Tire Response And The Effect On Roughness-Induced Vehicle Energy Dissipation, Gabriela Ann Lukanus Jul 2023

Dynamic Tire Response And The Effect On Roughness-Induced Vehicle Energy Dissipation, Gabriela Ann Lukanus

Master's Theses (2009 -)

Vehicle dynamics models rely on accurate inputs to quantify dynamic loading and energy dissipation to design pavement structures and assess the environmental impacts. The tire’s response to loading is one of the inputs used in these models, and it is typically represented by a linear spring and dashpot connected in parallel. However, tires are made of rubber, a viscoelastic material, so their load response depends on the excitation frequency. Yet, existing models do not incorporate this parameter. This thesis will first examine the load response and its variation with excitation frequency of two truck tires – a dual tire assembly …

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Deep Learning Classification Of Deep Ultraviolet Fluorescence Images For Margin Assessment During Breast Cancer Surgery, Tyrell To Jul 2023

Deep Learning Classification Of Deep Ultraviolet Fluorescence Images For Margin Assessment During Breast Cancer Surgery, Tyrell To

Master's Theses (2009 -)

Breast-conserving surgery (BCS) is a widely used treatment for breast cancer, but ensuring the complete removal of cancer cells from the surgical margins remains a challenge. Deep ultraviolet (DUV) fluorescence scanning microscopy offers a potential solution by providing real-time whole-surface imaging of resected tissues during BCS. However, interpreting DUV images for margin assessment requires an automated classification method. This dissertation addresses this need by proposing a deep learning-based classification approach for DUV fluorescence images in intra-operative margin assessment of breast cancer.To overcome the limited availability of DUV image datasets and potential over- fitting, the study combines patch-level classification using transfer …

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Reducing Porosity In Lpbf Ti-6al-4v By Parameter Optimization And Low Temperature Hot Isostatic Pressing Cycle, Penn Rawn Jul 2023

Reducing Porosity In Lpbf Ti-6al-4v By Parameter Optimization And Low Temperature Hot Isostatic Pressing Cycle, Penn Rawn

Master's Theses (2009 -)

Powder bed based additive manufacturing has advantages in its ability to make specialized parts with complex geometries. Unfortunately, components made through such processes of suffer from manufacturing defects including porosity. To study pore formation and removal, specimens of Ti-6Al-4V were built at varied levels of laser power, travel speed, hatch spacing, and layer thickness to obtain a variety of initial defect populations. The specimens were then subjected to a hot isostatic pressure (HIP) at 850 °C and 200 MPa to evaluate the low temperature high pressure (LTHP) cycle’s ability to remove pores. Image analysis was used to estimate the relative …

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The Effect Of Microstructural Defects And Geometrical Features On Fatigue Behavior Of Superelastic Nitinol Wires, Parisa Shabani Nezhad Jul 2023

The Effect Of Microstructural Defects And Geometrical Features On Fatigue Behavior Of Superelastic Nitinol Wires, Parisa Shabani Nezhad

Dissertations (1934 -)

Nitinol is an alloy of nickel and titanium, which exhibits outstanding functional properties, such as shape memory and superelastic behavior. Superelastic nitinol wires exhibit recoverable strains that are significantly greater than traditional alloys. In most of its applications, nitinol is exposed to cyclic loads, which results in functional and/or structural fatigue that ultimately leads to failure. The classical fatigue theories do not appropriately address the fatigue performance of superelastic nitinol due to the complex nature of the martensitic transformation. It has been shown that the main fatigue crack initiation sites, other than surfaces, are microstructural inhomogeneities such as voids and …

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Impact Of Traffic On Air Pollution In A Mid-Sized Urban City During Covid-19 Lockdowns, Nathan Hay, Otito Onwuzurike, Somesh Roy, Patrick J. Mcnamara, Margaret L. Mcnamara, Walter M. Mcdonald Jun 2023

Impact Of Traffic On Air Pollution In A Mid-Sized Urban City During Covid-19 Lockdowns, Nathan Hay, Otito Onwuzurike, Somesh Roy, Patrick J. Mcnamara, Margaret L. Mcnamara, Walter M. Mcdonald

Civil and Environmental Engineering Faculty Research and Publications

In this study, we evaluated the changes in air pollutant concentrations around Milwaukee, WI, during and after lockdown due to the COVID-19 pandemic for a period of 126 days. Measurements of particulate matter (PM1, PM2.5, and PM10), NH3, H2S, and O3 + NO2, were made on a 74-km route of arterial and highway roads from April to August 2020 using a Sniffer 4D sensor mounted to a vehicle. Traffic volume during measurement periods were estimated from smartphone-based traffic data. From lockdown (March 24, 2020–June 11, 2020) to …

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Pyrolysis—A Tool In The Wastewater Solids Handling Portfolio, Not A Silver Bullet: Benefits, Drawbacks, And Future Directions, Patrick J. Mcnamara, Zhongzhe Liu, Yiran Tong, Hari Santha, Lynne Moss, Daniel Zitomer May 2023

Pyrolysis—A Tool In The Wastewater Solids Handling Portfolio, Not A Silver Bullet: Benefits, Drawbacks, And Future Directions, Patrick J. Mcnamara, Zhongzhe Liu, Yiran Tong, Hari Santha, Lynne Moss, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

Pyrolysis is the process whereby carbonaceous materials, such as biosolids, are heated between 400°C and 900°C in the absence of oxygen. Three main products are generated: a solid product called biochar, a py-liquid that consists of aqueous phase and non-aqueous phase liquid, and py-gas. The biochar holds value as a beneficial soil amendment and sequesters carbon. The py-liquid is potentially hazardous and needs to be dealt with (including potentially reducing it on-site via catalysis or thermal oxidation). Py-gas can be used on-site for energy recovery. Pyrolysis has gained recent interest due to concern over per- and polyfluoroalkyl substances (PFAS) in …

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Scan2drawing: Use Of Deep Learning For As-Built Model Landscape Architecture, Sisi Han, Yuhan Jiang, Yilei Huang, Mingzhu Wang, Yong Bai, Andrea Spool-White May 2023

Scan2drawing: Use Of Deep Learning For As-Built Model Landscape Architecture, Sisi Han, Yuhan Jiang, Yilei Huang, Mingzhu Wang, Yong Bai, Andrea Spool-White

Biomedical Engineering Faculty Research and Publications

This paper presents an innovative and fully automatic solution of generating as-built computer-aided design (CAD) drawings for landscape architecture (LA) with three dimensional (3D) reality data scanned via drone, camera, and LiDAR. To start with the full pipeline, 2D feature images of ortho-image and elevation-map are converted from the reality data. A deep learning-based light convolutional encoder–decoder was developed, and compared with U-Net (a binary segmentation model), for image pixelwise segmentation to realize automatic site surface classification, object detection, and ground control point identification. Then, the proposed elevation clustering and segmentation algorithms can automatically extract contours for each instance from …

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Cortical Effects Of Wrist Tendon Vibration During An Arm Tracking Task In Chronic Stroke Survivors: An Eeg Study, Dylan B. Snyder, Scott A. Beardsley, Allison S. Hyngstrom, Brian D. Schmit May 2023

Cortical Effects Of Wrist Tendon Vibration During An Arm Tracking Task In Chronic Stroke Survivors: An Eeg Study, Dylan B. Snyder, Scott A. Beardsley, Allison S. Hyngstrom, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

The purpose of this study was to characterize changes in cortical activity and connectivity in stroke survivors when vibration is applied to the wrist flexor tendons during a visuomotor tracking task. Data were collected from 10 chronic stroke participants and 10 neurologically-intact controls while tracking a target through a figure-8 pattern in the horizontal plane. Electroencephalography (EEG) was used to measure cortical activity (beta band desynchronization) and connectivity (beta band task-based coherence) with movement kinematics and performance error also being recorded during the task. All participants came into our lab on two separate days and performed three blocks (16 trials …

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Feasibility Of Sewer Overflow Treatment Using Chemical Oxidation After Rapid Solids Removal, Paige Peters Apr 2023

Feasibility Of Sewer Overflow Treatment Using Chemical Oxidation After Rapid Solids Removal, Paige Peters

Dissertations (1934 -)

Sewer overflows discharge 850 billion gallons of untreated sewage into U.S. lakes and rivers every year during high-intensity precipitation events. Common approaches include storage tanks or rapid solids removal followed by chlorine disinfection. These approaches can be capital intensive and only achieve partial treatment. A decentralized, end-of-pipe sewer overflow treatment system would eliminate detrimental overflow effects while handling highly variable flow and pollutant loading. Specifically, the rapid reaction rate of chemical oxidation can achieve soluble organics removal and disinfection of chlorine-resistant pathogens in a small footprint. To address the overflow issue, an advanced high-rate treatment system (AH-RTS) was developed and …

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Algorithm-Architecture-Hardware Co-Design In Computing Systems: From Chip Multicore To The Cloud, Wenkai Guan Apr 2023

Algorithm-Architecture-Hardware Co-Design In Computing Systems: From Chip Multicore To The Cloud, Wenkai Guan

Dissertations (1934 -)

The computational demands for training deep learning models doubled every three months recently. However, according to Moore’s Law, the computational power available only doubled every two years. To bridge this demand-supply gap while optimizing energy consumption and carbon emission, through my dissertation, we propose a novel algorithm-architecture-hardware co-design cross-layer approach for computing systems: from chip multicore to the cloud. At the Chip Multicore Level: How can we design high-performance network-on-chip based multiprocessors that are reliable to uncertainty in design parameters? This dissertation answered this question by 1) laying the foundation for uncertainty modeling and robust multi-objective optimization for embedded systems …

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Electrocoagulation For Treatment Of Disinfection Byproducts, Organic Matter, And Per-And Polyfluoroalykl Substances., Donald Rockwood Ryan Apr 2023

Electrocoagulation For Treatment Of Disinfection Byproducts, Organic Matter, And Per-And Polyfluoroalykl Substances., Donald Rockwood Ryan

Dissertations (1934 -)

Technologies are needed to treat contaminants such as disinfection byproducts (DBPs), trace organic compounds (TOrCs), and per- and polyfluoroalkyl substances (PFAS) in water to improve consumer safety and mitigate chronic risk. This dissertation focused on evaluating electrocoagulation (EC) and hydrogen peroxide (H2O2)-enhanced EC (peroxi-electrocoagulation; EC:H2O2) for treatment of these contaminants. The impacts of source water quality (such as natural organic matter [NOM]) on overall performance was assessed and the non-destructive and destructive pathways involved in treatment were evaluated. The first objective focused on EC performance for mitigating the formation of regulated DBPs in water to better substantiate EC’s performance relative …

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An Inexpensive, Reproducible Method To Quantify Activated Sludge Foaming Potential: Validation Through Lab-Scale Studies And Year-Long Full-Scale Sampling Campaign, Grace K. Scarim, Emily Lou Lamartina, Kaushik Venkiteshwaran, Daniel Zitomer, Ryan J. Newton, Patrick J. Mcnamara Apr 2023

An Inexpensive, Reproducible Method To Quantify Activated Sludge Foaming Potential: Validation Through Lab-Scale Studies And Year-Long Full-Scale Sampling Campaign, Grace K. Scarim, Emily Lou Lamartina, Kaushik Venkiteshwaran, Daniel Zitomer, Ryan J. Newton, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Activated sludge is a conventional treatment process for biochemical oxygen demand (BOD) and total suspended solids (TSS) removal at water resource recovery facilities (WRRFs). Foaming events are a common operational issue in activated sludge and can lead to decreased treatment efficiency, maintenance issues, and potential environmental health risks. Stable foaming events are caused by biological and chemical drivers (i.e., microbes and surfactants) during the aeration process. However, foaming events are difficult to predict and quantify. We present an inexpensive and easy-to-use method that can be applied at WRRFs to quantify foaming potential. Subsequently, the method was applied over a year-long …

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Urban Water Quality: Socio-Economic Distribution Of Stream Degradation, And The Influence Of Climate On Bmp Performance, Isabelle Horvath Apr 2023

Urban Water Quality: Socio-Economic Distribution Of Stream Degradation, And The Influence Of Climate On Bmp Performance, Isabelle Horvath

Dissertations (1934 -)

Urban water quality impairments have long burdened urban aquatic ecosystems in a phenomenon termed “urban stream syndrome”. The symptoms of this “syndrome” include physical changes in stream morphology and water level, biologically stressed environments, and perturbations in ecosystem processes. Despite years of research and costly investments in restoration and rehabilitation, urban waterways are still plagued by degradation. Improvement in urban water quality will require multi-faceted efforts, including progress on 2 key fronts 1) increased understanding of current impairments, and 2) increased knowledge about urban stormwater infrastructure like best management practices (BMPs). Towards both topics, engineers have quantified the influence of …

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Evaluating The Impact Of Land Use Changes, Drivers Of Tmdl Development, And Green Infrastructure On Stream Impairments, Charitha Jayasri Gunawardana Apr 2023

Evaluating The Impact Of Land Use Changes, Drivers Of Tmdl Development, And Green Infrastructure On Stream Impairments, Charitha Jayasri Gunawardana

Dissertations (1934 -)

Despite the water quality improvements and regulatory advancements over the last 50 years since the enactment of the Clean Water Act, water bodies within the United States are still impaired for a broad range of contaminants from non-point source pollution. Improving watershed management approaches to meet this challenge will require a greater understanding of (1) how changes within a watershed, such as changing land use, impact stream water quality, (2) what influence socioeconomic, spatial and political factors may have on the progress towards meeting water quality goals, such as those set within Total Maximum Daily Loads (TMDLs), and (3) how …

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Transfer Learning, Model Interpretation, And Dataset Bias Analysis For Automated Violence Detection From Video, Erik Clemens Apr 2023

Transfer Learning, Model Interpretation, And Dataset Bias Analysis For Automated Violence Detection From Video, Erik Clemens

Master's Theses (2009 -)

Many communities have installed surveillance cameras in an effort to deter and respond to violence.Due to the difficulty of constantly monitoring such camera feeds, these systems are rarely used to provide real-time information. To enable rapid alerts and information for first responders, this thesis develops a proof-of-concept system capable of automatically detecting violence from video footage. This system is developed by fine-tuning a convolutional neural network that has previously demonstrated success on general action recognition tasks. This thesis explores two new techniques to improve the accuracy of the fine-tuned model. The first is a data augmentation technique that generates aspect …

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Soot Formation And Ignition Characteristics Of Gasoline/Ethanol Fuel Blends Using A Rapid Compression Machine, Joseph Richard Keller Gross Apr 2023

Soot Formation And Ignition Characteristics Of Gasoline/Ethanol Fuel Blends Using A Rapid Compression Machine, Joseph Richard Keller Gross

Master's Theses (2009 -)

With the growing societal concern toward vehicle emissions, renewableforms of fuel are garnering increased interest in the fuel research world. While electrification is prevalent amongst the light duty sector, many challenges arise for such type of powerplant in heavy duty vehicles. Further, current heavy duty mixing-controlled combustion uses diesel fuel, which produces significant black carbon emissions in the exhaust. Alcohol fuels from biological sources serve as a promising source ofrenewable energy for heavy duty engines. The soot emissions and thermodynamic properties of ethanol/gasoline blended fuels must be understood and quantified in order to develop heavy duty combustion engine technology capable …

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Seismically Induced Column Buckling In Special Concentrically Braced Frames In Steel Buildings, Noah Meisner Apr 2023

Seismically Induced Column Buckling In Special Concentrically Braced Frames In Steel Buildings, Noah Meisner

Master's Theses (2009 -)

Special concentrically braced frames (SCBFs) are efficient lateral-force-resisting systems that are specifically detailed for steel buildings in regions with high seismic hazard. Current design standards for SCBFs intend to ensure inelastic deformation capacity through strict ductile and capacity-based design requirements. Braces are intended to yield in tension and buckle in compression to dissipate seismic energy. The current standards apply expected brace forces to all framing elements and connections to concentrate yielding in the braces. In these standards it is conservatively assumed that brace yielding and buckling simultaneously occur on all stories, and columns are designed considering the accumulated brace demands …

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Design, Realization, And Verification Of A Planar, Tendon-Driven, Variable Stiffness Finger, Allison Goetz Apr 2023

Design, Realization, And Verification Of A Planar, Tendon-Driven, Variable Stiffness Finger, Allison Goetz

Master's Theses (2009 -)

Traditional robotic manipulators are designed for accurate absolute positioning and require a highly structured environment to perform simple operations. They are unable to compensate for small discrepancies in the relative positioning of the robot end-effector with respect to its environment. A task-appropriate compliance allows a robotic manipulator to compensate for small discrepancies in the position or orientation of an object when the object is constrained. A better means of realizing task-appropriate structured compliant behavior is needed to allow a robot to perform dexterous manipulation.In this thesis, three agonist-antagonist variable stiffness actuators (VSAs) are used to independently control the joint stiffnesses …

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Effect Of Storage Condition On Penetration Threshold Of Porcine Skin Tissue, Jared Michael Koser Apr 2023

Effect Of Storage Condition On Penetration Threshold Of Porcine Skin Tissue, Jared Michael Koser

Master's Theses (2009 -)

Buried blast explosions create small projectiles which can become lodged in the tissue of personnel as far away as hundreds of meters. Without appropriate treatment, these lodged projectiles can become a source of infection and prolonged injury to soldiers in modern combat. Human cadavers can be used as surrogates for living humans for ballistic penetration testing, but human cadavers are frozen during transport and storage. The process of freezing and thawing the tissue before testing may change the biomechanical properties of the tissue. The goal of the current study was to investigate the effect of tissue storage on penetration threshold …

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Usage Of Drone For Building Facade Inspection, Sahara Adhikari Apr 2023

Usage Of Drone For Building Facade Inspection, Sahara Adhikari

Master's Theses (2009 -)

The taller the building the higher the risk caused by pieces breaking off from the building façade. 13 major cities in the USA have regulations that mandate building façade inspected by a certified professional as per regulations imposed by local authority. Conventional ways of inspecting build facades are manual contact methods where a certified professional inspects the building façade with the help of scaffolding, mobile cranes, or monorails. Visual inspections with contact methods face several challenges, including poor safety, productivity, and reliability. The results of visual inspection can be reliable when dealing with small structures with easily visible parts, but …

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Downstream Task Self-Supervised Learning For Object Recognition And Tracking, Abubakar Siddique Apr 2023

Downstream Task Self-Supervised Learning For Object Recognition And Tracking, Abubakar Siddique

Dissertations (1934 -)

This dissertation addresses three limitations of deep learning methods in image and video understanding-based machine vision applications. Firstly, although deep convolutional neural networks (CNNs) are efficient for image recognition applications such as object detection and segmentation, they perform poorly under perspective distortions. In real-world applications, the camera perspective is a common problem that we can address by annotating large amounts of data, thus limiting the applicability of the deep learning models. Secondly, the typical approach for single-camera tracking problems is to use separate motion and appearance models, which are expensive in terms of computations and training data requirements. Finally, conventional …

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Probabilistic Model Development And Risk Management Strategies For Pipelines With Anomalies, Kiswendsida Jules Kere Apr 2023

Probabilistic Model Development And Risk Management Strategies For Pipelines With Anomalies, Kiswendsida Jules Kere

Dissertations (1934 -)

Metal pipelines are exposed to many threats such as corrosion and cracking during their service life, which can weaken pipeline integrity and cause leaks or ruptures, leading to significant safety, economic and environmental consequences. For corrosion, many models have been developed to predict failure pressure of pipeline with an isolated defect, and only a few models consider interacting defects. On the other hand, the existing models for predicting failure pressure of pipeline with crack defects are very limited. Several model performance evaluations have shown that most of the existing models for either corrosion or cracking-like defects are conservative since they …

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Design And Advanced Model Predictive Control Of Wide Bandgap Based Power Converters, Waqar Ahmed Khan Apr 2023

Design And Advanced Model Predictive Control Of Wide Bandgap Based Power Converters, Waqar Ahmed Khan

Dissertations (1934 -)

The field of power electronics (PE) is experiencing a revolution by harnessing the superior technical characteristics of wide-band gap (WBG) materials, namely Silicone Carbide (SiC) and Gallium Nitride (GaN). Semiconductor devices devised using WBG materials enable high temperature operation at reduced footprint, offer higher blocking voltages, and operate at much higher switching frequencies compared to conventional Silicon (Si) based counterpart. These characteristics are highly desirable as they allow converter designs for challenging applications such as more-electric-aircraft (MEA), electric vehicle (EV) power train, and the like. This dissertation presents designs of a WBG based power converters for a 1 MW, 1 …

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Computationally Efficient Analysis And Optimization Of Induction Motors, Hossein Nejadi Koti Apr 2023

Computationally Efficient Analysis And Optimization Of Induction Motors, Hossein Nejadi Koti

Dissertations (1934 -)

The goal of this dissertation is to establish computationally efficient large-scale design optimization procedures for induction motors that are not only computationally efficient, but also do not sacrifice the accuracy of the results. To achieve this goal, the topic of the lengthy numerical transient response of Time-Stepping Finite Element Analysis (TS-FEA) of induction motors was investigated. This is because this lengthy transient affects the computational efficiency aspect of the optimization process. The effect of different parameters on the numerical transient response phenomenon were studied, and two different techniques for mitigation of this numerical transient were evaluated. The superior one amongst …

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Automated Combustion Model Classification For Char Particle Distributions Using 3-D Morphology Analysis And Pore-Resolving Cfd Simulations, Dongyu Liang, Simcha L. Singer Mar 2023

Automated Combustion Model Classification For Char Particle Distributions Using 3-D Morphology Analysis And Pore-Resolving Cfd Simulations, Dongyu Liang, Simcha L. Singer

Mechanical Engineering Faculty Research and Publications

Combustion of pulverized coal involves millions of particles with a distribution of morphologies. A workflow is presented to characterize, classify, and model distributions of highly porous coal char particles. To understand the impacts of morphology, 3-D pore-resolving combustion simulations for 150 particles imaged with micro-CT are first performed. To facilitate modeling distributions of morphology in reactor-scale CFD, a machine learning algorithm is then trained to classify particles according to their expected combustion behavior and to select an accurate, computationally efficient 1-D particle-scale combustion model. Whereas existing approaches classify particles solely according to morphology and use 2-D measurements, the present approach …

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Development Of Fibroblast/Endothelial Cell-Seeded Collagen Scaffolds For In Vitro Prevascularization, Daniela S. Masson-Meyers, Fahimeh Tabatabaei, Lane Steinhaus, Jeffrey M. Toth, Lobat Tayebi Mar 2023

Development Of Fibroblast/Endothelial Cell-Seeded Collagen Scaffolds For In Vitro Prevascularization, Daniela S. Masson-Meyers, Fahimeh Tabatabaei, Lane Steinhaus, Jeffrey M. Toth, Lobat Tayebi

Biomedical Engineering Faculty Research and Publications

The development of vascularized scaffolds remains one of the major challenges in tissue engineering, and co-culturing with endothelial cells is known as one of the possible approaches for this purpose. In this approach, optimization of cell culture conditions, scaffolds, and fabrication techniques is needed to develop tissue equivalents that will enable in vitro formation of a capillary network. Prevascularized equivalents will be more physiologically comparable to the native tissues and potentially prevent insufficient vascularization after implantation. This study aimed to culture human umbilical vein endothelial cells (HUVECs), alone or in co-culture with fibroblasts, on collagen scaffolds prepared by simple fabrication …

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Pyrolysis Transports, And Transforms, Pfas From Biosolids To Py-Liquid, Patrick J. Mcnamara, Melvin S. Samuel, Sandeep Sathyamoorthy, Lynne Moss, Danny Valtierra, Hugo Cortes Lopez, Nicholas J. Nigro, Stephen Somerville, Zhongzhe Liu Feb 2023

Pyrolysis Transports, And Transforms, Pfas From Biosolids To Py-Liquid, Patrick J. Mcnamara, Melvin S. Samuel, Sandeep Sathyamoorthy, Lynne Moss, Danny Valtierra, Hugo Cortes Lopez, Nicholas J. Nigro, Stephen Somerville, Zhongzhe Liu

Civil and Environmental Engineering Faculty Research and Publications

Per- and poly-fluoroalkyl substances (PFAS) in wastewater solids have resulted in bans on land application of biosolids, causing utilities to explore thermal treatment options. Pyrolysis is a thermal treatment process that converts wastewater solids to biochar, py-liquid (i.e., aqueous phase liquid and non-aqueous phase liquid), and py-gas. Research on the impact of pyrolysis on PFAS in biosolids has yielded mixed results, and no research has investigated if PFAS are present in the py-liquid. The goals of this research were to determine if pyrolysis releases PFAS with the effluent py-liquid and to distinguish “removal” from “transformation” of PFAS. Triplicate …

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