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Articles 361 - 390 of 2086

Full-Text Articles in Engineering

Machine Learning-Based Temporary Traffic Control Cost Analysis, Yuhan Jiang, Sisi Han, Yong Bai Aug 2020

Machine Learning-Based Temporary Traffic Control Cost Analysis, Yuhan Jiang, Sisi Han, Yong Bai

Civil and Environmental Engineering Faculty Research and Publications

In a design-bid-build infrastructural project, the agency may use a lump-sum, or unit-price for temporary traffic control (TTC) items, while their cost is hard to estimate. This paper presents the research results of developing a machine learning model of the relationship between the TTC items’ cost with the project total cost and non-TTC items in infrastructural projects. In detail, 163 infrastructural projects’ data were collected for analyzing two research questions: first, the relationship between the TTC items with the project total cost and non-TTC items; second, the relationship between the TTC items’ payment option with the project total cost and …

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Estimation Of Construction Site Elevations Using Drone-Based Orthoimagery And Deep Learning, Yuhan Jiang, Yong Bai Aug 2020

Estimation Of Construction Site Elevations Using Drone-Based Orthoimagery And Deep Learning, Yuhan Jiang, Yong Bai

Civil and Environmental Engineering Faculty Research and Publications

Using deep learning to recover depth information from a single image has been studied in many situations, but there are no published articles related to the determination of construction site elevations. This paper presents the research results of developing and testing a deep learning model for estimating construction site elevations using a drone-based orthoimage. The proposed method includes an orthoimage-based convolutional neural network (CNN) encoder, an elevation map CNN decoder, and an overlapping orthoimage disassembling and elevation map assembling algorithm. In the convolutional encoder-decoder network model, the max pooling and up-sampling layers link the orthoimage pixel and elevation map pixel …

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Understanding The Laser Powder Bed Fusion Of Alsi10mg Alloy, Holden Hyer, Le Zhou, Sharon Park, Guilherme Gottsfritz, George Benson, Bjorn Tolentino, Brandon Mcwilliams, Kyu Cho, Yongho Sohn Aug 2020

Understanding The Laser Powder Bed Fusion Of Alsi10mg Alloy, Holden Hyer, Le Zhou, Sharon Park, Guilherme Gottsfritz, George Benson, Bjorn Tolentino, Brandon Mcwilliams, Kyu Cho, Yongho Sohn

Mechanical Engineering Faculty Research and Publications

We examine the microstructural characteristics of LPBF AlSi10Mg produced by using a wide range of LPBF processing parameters with independently varied laser power, hatch spacing, scan speed, slice thickness, and the normalized energy density. The lower energy density produced lack of fusion flaws from residual interparticle spacing, while the higher energy density produced spherical pores from trapped gas. The highest density (> 99%) samples were produced by using an energy density of 32 to 54 J/mm3. Within this energy density range, use of smaller slice thicknesses increased the processing window that would produce dense AlSi10Mg samples. A cellular …

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The Effect Of Discrete Visual Perturbations On Balance Control During Gait, Lara I. Riem, Brian D. Schmit, Scott A. Beardsley Jul 2020

The Effect Of Discrete Visual Perturbations On Balance Control During Gait, Lara I. Riem, Brian D. Schmit, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Immersive virtual reality provides a safe and costeffective approach to administrating balance disruption during ambulation. Previous research has explored the effects of applying continuous perturbations in a virtual environment to challenge balance. This pilot study investigates the ability to disrupt balance with discrete visual perturbations during ambulation in healthy young adults. During the study participants walked on a treadmill within a virtual environment. As they walked the entire visual scene was intermittently shifted to the left or right 1 meter over 1 second. The results demonstrate a significant decrease in step length (𝑝 <; 0.05) and change in center of mass excursion (𝑝 <; 0.05) across participants (𝑁=13). Changes in gait lasted up to three steps after application, suggesting a consistent challenge to dynamic balance control as a result of the discrete visual perturbation. Further, participants did not demonstrate a reduction in response to the discrete visual perturbation with repeated exposure. The results indicate that discrete visual perturbations of a virtual scene can be used to challenge gait and modulate center of mass sway. The use of visual perturbations within a virtual environment to challenge dynamic balance could provide a safer and more affordable avenue for balance rehabilitation by reducing the need for systems that physically perturb balance.

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A Temperature Sensor For Measuring Dielectric Loss Heating In A Dielectrophoresis Device, Imtiaz Hossen Jul 2020

A Temperature Sensor For Measuring Dielectric Loss Heating In A Dielectrophoresis Device, Imtiaz Hossen

Master's Theses (2009 -)

Dielectrophoresis is an extensively used technique in the field of biomedical science that manipulates particles in a non-uniform electric field. One of its drawbacks is heat dissipation during the DEP operation that raises the local temperature of the DEP device. Temperature increases during dielectrophoresis (DEP) can affect the response of biological entities and ignoring the effect can mislead the result of the analysis. The heating mechanism of a DEP device is typically considered to be the result of Joule heating as bare electrodes are used in a conductive solution. However, when electrodes are insulated from the solution the presence of …

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Speeding Up Particle Filter Algorithm For Tracking Multiple Targets Using Cuda Programming, Jinhua Zhang Jul 2020

Speeding Up Particle Filter Algorithm For Tracking Multiple Targets Using Cuda Programming, Jinhua Zhang

Master's Theses (2009 -)

This thesis proposes to work on a parallelization method to speed up the computational runtime of the particle filter algorithm for multiple targets tracking. CUDA programming is utilized to execute the original implementation of the particle filter algorithm on GPU. The thesis provides a detailed discussion of the background information on the relevant topics. And then a presentation of the code architecture changes is followed. The detailed CUDA-based implementation is illustrated and discussed, which is followed by a discussion andcomparison of the results obtained from a series of tests.In this thesis, the introduction and description of the basic …

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Determining The Correlation Between Plantar Pressure And Joint Kinematics While Running, Fadumo Khalid Mohamud Jul 2020

Determining The Correlation Between Plantar Pressure And Joint Kinematics While Running, Fadumo Khalid Mohamud

Master's Theses (2009 -)

Running provides many health benefits, but there is a risk for lower extremity injuries. Previous studies have performed simultaneous assessments of plantar pressure and joint kinematics; however, they have not investigated correlations between these parameters. The goal of this study was to assess correlations between joint kinematics and plantar pressure metrics during the stance phase.Fifteen female and eleven male recreational runners ran ten trials in this study. The joint kinematics were measured using the Vicon MX system and plantar pressure metrics were measured with the Quasar pressure treadmill. Spearman rho correlation tests were performed to determine correlations between joint …

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Investigation Of Optimization Targets For Predictive Simulation Of Human Gait With Model Predictive Control, Jessica Brianne Thayer Jul 2020

Investigation Of Optimization Targets For Predictive Simulation Of Human Gait With Model Predictive Control, Jessica Brianne Thayer

Master's Theses (2009 -)

The design and development of gait-related treatments and devices is inhibited by anabsence of predictive gait models. Understanding of human gait and what motivates walkingpatterns is still limited, despite walking being one of the most routine human activities. While asignificant body of literature exists on gait modeling and optimization criteria to achievesimulated, normal gait, particularly with neuromuscular models, few studies have aimed to applyoptimization targets which approximate metabolic cost to mechanical gait models. Even fewerhave attempted this predictively, with no joint angle data specified a priori. The Sunmodel [31], [32] is one such …

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A Parametric Study Of Cohesive Zone Modeling Applied To Interfaces Under High Impact Velocity Collisions, Tamanna Tasnim Jul 2020

A Parametric Study Of Cohesive Zone Modeling Applied To Interfaces Under High Impact Velocity Collisions, Tamanna Tasnim

Master's Theses (2009 -)

Understanding the response of energetic materials to dynamic loading is critical for the design and safety of energetic systems. Energetic materials may contain heterogeneous microstructures, and hotspots can form at microstructural interfaces. The hotspots in these microstructures can determine if a material is safe to use. This study presents an analysis of the effect of material interfaces on the dynamic behavior of a heterogeneous sandwich structure subjected to high-velocity impacts using the cohesive zone model. The current work explores the sensitivity of a sugar-PMMA heterogeneous system to interface properties like stiffness, strength, and fracture energy both for normal and oblique …

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Using Drone-Based Fully Convolutional Network For The Determination Of Construction Site Elevations, Sisi Han Jul 2020

Using Drone-Based Fully Convolutional Network For The Determination Of Construction Site Elevations, Sisi Han

Master's Theses (2009 -)

This thesis presents the research results of using the Fully Convolutional Network (FCN) model to densely match pixels and accurately determine elevations utilizing low-high ortho-images on a construction site. The research project has three major tasks. First, this researcher developed the FCN model to build up the relations between the reference pixels’ patches from the low-ortho-image and the target pixels’ patches from the high-ortho-image, which are approximate 2:1 scale relations. The developed FCN model has two convolutional blocks and one max-pooling layer in the middle. 286,292 samples of well-matched reference patches and target patches were collected for training the FCN …

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Determination Of Elevations For Excavation Operations Using Drone Technologies, Yuhan Jiang Jul 2020

Determination Of Elevations For Excavation Operations Using Drone Technologies, Yuhan Jiang

Dissertations (1934 -)

Using deep learning technology to rapidly estimate depth information from a single image has been studied in many situations, but it is new in construction site elevation determinations, and challenges are not limited to the lack of datasets. This dissertation presents the research results of utilizing drone ortho-imaging and deep learning to estimate construction site elevations for excavation operations. It provides two flexible options of fast elevation determination including a low-high-ortho-image-pair-based method and a single-frame-ortho-image-based method. The success of this research project advanced the ortho-imaging utilization in construction surveying, strengthened CNNs (convolutional neural networks) to work with large scale images, …

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Shock Processes In Water: Multi-Scale Comparison And Experimental Results, Longhao Huang Jul 2020

Shock Processes In Water: Multi-Scale Comparison And Experimental Results, Longhao Huang

Dissertations (1934 -)

Water as the most common fluid on earth has extraordinary properties. The understanding of the dynamic response of water is important to planetary physics, biology and medicine. Inspired by the relationship between shockwave thicknesses and the intensity of property changes between pre-shock and post-shock states in gas medium, it is interesting to study the response of a liquid medium within shock process, such as liquid argon or water, from numerical and experimental methods, especially from different scales of simulations (continuum and molecular dynamics).Molecular Dynamics (MD) simulations of Hugoniot hydrostatic compression and shockwave propagation processes are performed via Large-Scale Atomic/Molecular Massively …

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Multi-Homotopy Class Optimal Path Planning For Manipulation With One Degree Of Redundancy, Jacob J. Rice, Joseph M. Schimmels Jul 2020

Multi-Homotopy Class Optimal Path Planning For Manipulation With One Degree Of Redundancy, Jacob J. Rice, Joseph M. Schimmels

Mechanical Engineering Faculty Research and Publications

Redundant manipulators have an infinitely large set of joint paths that yield a desired end-effector path in the task space. A unique joint path can be obtained by minimizing a global cost function. Prior optimal control methods minimize a global cost function to find a local minimum within a homotopy class. Many possible locally optimal joint paths are in different homotopy classes. This paper presents an algorithm that effectively searches the solution space and finds many locally optimal paths in all relevant homotopy classes. The path with the lowest cost is very likely the globally optimal path. The algorithm is …

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Dynamic Modeling And Optimal Design For Net Zero Energy Houses Including Hybrid Electric And Thermal Energy Storage, Huangjie Gong, Vandana Rallabandi, Dan M. Ionel, Donald Colliver, Shaun Duerr, Cristinel Ababei Jul 2020

Dynamic Modeling And Optimal Design For Net Zero Energy Houses Including Hybrid Electric And Thermal Energy Storage, Huangjie Gong, Vandana Rallabandi, Dan M. Ionel, Donald Colliver, Shaun Duerr, Cristinel Ababei

Electrical and Computer Engineering Faculty Research and Publications

Net zero energy (NZE) houses purchase zero net metered electricity from the grid over a year. Technical challenges brought forth by NZE homes are related to the intermittent nature of solar generation, and are due to the fact that peak solar generation and load are not coincident. This leads to a large rate of change of load, and in case of high PV penetration communities, often requires the installation of gas power plants to service this variability. This article proposes a hybrid energy storage system including batteries and a variable power electric water heater which enables the NZE homes to …

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Task-Specific Versus Impairment-Based Training On Locomotor Performance In Individuals With Chronic Spinal Cord Injury: A Randomized Crossover Study, Jennifer K. Lotter, Christopher E. Henderson, Abby Plawecki, Molly E. Holthus, Emily H. Lucas, Marzieh M. Ardestani, Brian D. Schmit, George Hornby Jul 2020

Task-Specific Versus Impairment-Based Training On Locomotor Performance In Individuals With Chronic Spinal Cord Injury: A Randomized Crossover Study, Jennifer K. Lotter, Christopher E. Henderson, Abby Plawecki, Molly E. Holthus, Emily H. Lucas, Marzieh M. Ardestani, Brian D. Schmit, George Hornby

Biomedical Engineering Faculty Research and Publications

Background. Many research studies attempting to improve locomotor function following motor incomplete spinal cord injury (iSCI) focus on providing stepping practice. However, observational studies of physical therapy strategies suggest the amount of stepping practice during clinical rehabilitation is limited; rather, many interventions focus on mitigating impairments underlying walking dysfunction. Objective. The purpose of this blinded-assessor randomized trial was to evaluate the effects of task-specific versus impairment-based interventions on walking outcomes in individuals with iSCI. Methods. Using a crossover design, ambulatory participants with iSCI >1-year duration performed either task-specific (upright stepping) or impairment-based training for up to 20 sessions over ≤6 …

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The Neural Foundations Of Handedness: Insights From A Rare Case Of Deafferentation, S.A.L. Jayasinghe, F. R. Sarlegna, Robert A. Scheidt, R. L. Sainburg Jul 2020

The Neural Foundations Of Handedness: Insights From A Rare Case Of Deafferentation, S.A.L. Jayasinghe, F. R. Sarlegna, Robert A. Scheidt, R. L. Sainburg

Biomedical Engineering Faculty Research and Publications

The role of proprioceptive feedback on motor lateralization remains unclear. We asked whether motor lateralization is dependent on proprioceptive feedback by examining a rare case of proprioceptive deafferentation (GL). Motor lateralization is thought to arise from asymmetries in neural organization, particularly at the cortical level. For example, we have previously provided evidence that the left hemisphere mediates optimal motor control that allows execution of smooth and efficient arm trajectories, while the right hemisphere mediates impedance control that can achieve stable and accurate final arm postures. The role of proprioception in both of these processes has previously been demonstrated empirically, bringing …

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Modeling And Simulation Of A 20kv Ultra-Fast Dc Circuit Breaker For Electric Shipboard Applications, Trevor Arvin, Jiangbiao He, Nathan Weise, Tiefu Zhao Jun 2020

Modeling And Simulation Of A 20kv Ultra-Fast Dc Circuit Breaker For Electric Shipboard Applications, Trevor Arvin, Jiangbiao He, Nathan Weise, Tiefu Zhao

Electrical and Computer Engineering Faculty Research and Publications

A novel hybrid circuit breaker for medium voltage dc (MVDC) electric shipboard power systems is proposed. The breaker combines the benefits of the efficiency of a mechanical breaker and the interruption speed of a solid-state breaker. The proposed breaker utilizes a fast-ramping current source with a fast-actuating vacuum interrupter (VI) to provided ultra-fast response time and high on-state efficiency. During normal operation, nominal load current flows through the vacuum interrupter in the main conduction branch, providing a low-resistance path with negligible losses. During a fault, a current zero crossing is achieved by the use of a controllable resonant current source …

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Rainfall Manipulation Experiments As Simulated By Terrestrial Biosphere Models: Where Do We Stand?, Athanasios Paschalis, Simone Fatichi, Jakob Zscheischler, Philippe Ciais, Michael Bahn, Lena Boysen, Jinfeng Chang, Martin De Kauwe, Marc Estiarte, Daniel Goll, Paul J. Hanson, Anna B. Harper, Enqing Hou, Jaime Kigel, Alan K. Knapp, Klaus S. Larsen, Wei Li, Sebastian Lienert, Yiqi Luo, Patrick Meir, Julia E.M.S. Nabel, Romà Ogaya, Anthony J. Parolari, Changhui Peng, Josep Peñuelas, Julia Pongratz, Serge Rambal, Inger K. Schmidt, Hao Shi, Marcelo Sternberg, Hanqin Tian, Elisabeth Tschumi, Anna Ukkola, Sara Vicca, Nicolas Viovy, Ying-Ping Wang, Zhuonan Wang, Karina Williams, Donghai Wu, Qiuan Zhu Jun 2020

Rainfall Manipulation Experiments As Simulated By Terrestrial Biosphere Models: Where Do We Stand?, Athanasios Paschalis, Simone Fatichi, Jakob Zscheischler, Philippe Ciais, Michael Bahn, Lena Boysen, Jinfeng Chang, Martin De Kauwe, Marc Estiarte, Daniel Goll, Paul J. Hanson, Anna B. Harper, Enqing Hou, Jaime Kigel, Alan K. Knapp, Klaus S. Larsen, Wei Li, Sebastian Lienert, Yiqi Luo, Patrick Meir, Julia E.M.S. Nabel, Romà Ogaya, Anthony J. Parolari, Changhui Peng, Josep Peñuelas, Julia Pongratz, Serge Rambal, Inger K. Schmidt, Hao Shi, Marcelo Sternberg, Hanqin Tian, Elisabeth Tschumi, Anna Ukkola, Sara Vicca, Nicolas Viovy, Ying-Ping Wang, Zhuonan Wang, Karina Williams, Donghai Wu, Qiuan Zhu

Civil and Environmental Engineering Faculty Research and Publications

Changes in rainfall amounts and patterns have been observed and are expected to continue in the near future with potentially significant ecological and societal consequences. Modelling vegetation responses to changes in rainfall is thus crucial to project water and carbon cycles in the future. In this study, we present the results of a new model‐data intercomparison project, where we tested the ability of 10 terrestrial biosphere models to reproduce the observed sensitivity of ecosystem productivity to rainfall changes at 10 sites across the globe, in nine of which, rainfall exclusion and/or irrigation experiments had been performed. The key results are …

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Cell Surface-Expression Of The Phosphate-Binding Protein Psts: System Development, Characterization, And Evaluation For Phosphorus Removal And Recovery, Faten Hussein, Kaushik Venkiteshwaran, Brooke K. Mayer Jun 2020

Cell Surface-Expression Of The Phosphate-Binding Protein Psts: System Development, Characterization, And Evaluation For Phosphorus Removal And Recovery, Faten Hussein, Kaushik Venkiteshwaran, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Simultaneous overabundance and scarcity of inorganic phosphate (Pi) is a critical issue driving the development of innovative water/wastewater treatment technologies that not only facilitate Pi removal to prevent eutrophication, but also recover Pi for agricultural reuse. Here, a cell-surface expressed high-affinity phosphate binding protein (PstS) system was developed, and its Pi capture and release potential was evaluated. E. coli was genetically modified to express PstS on its outer membrane using the ice nucleation protein (INP) as an anchoring motif. Verification of protein expression and localization were performed utilizing SDS-polyacrylamide gel electrophoresis (SDS-PAGE), western blot, and …

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Process-Dependent Composition, Microstructure, And Printability Of Al-Zn-Mg And Al-Zn-Mg-Sc-Zr Alloys Manufactured By Laser Powder Bed Fusion, Le Zhou, Holden Hyer, Saket Thapliyal, Rajiv S. Mishra, Brandon Mcwilliams, Kyu Cho, Yongho Sohn Jun 2020

Process-Dependent Composition, Microstructure, And Printability Of Al-Zn-Mg And Al-Zn-Mg-Sc-Zr Alloys Manufactured By Laser Powder Bed Fusion, Le Zhou, Holden Hyer, Saket Thapliyal, Rajiv S. Mishra, Brandon Mcwilliams, Kyu Cho, Yongho Sohn

Mechanical Engineering Faculty Research and Publications

Additive manufacturing (AM) technology for metallic alloys such as laser powder bed fusion (LPBF) brings tremendous opportunities for development of novel alloys specifically designed for AM that would desensitize the inherent process variability and requires a refined understanding of processing–structure–property relationship that would contribute to future alloy development. In this study, two different alloys, Al-6Zn-2Mg and Al-6Zn-2Mg-0.7Sc-0.3Zr in wt. pct, representing traditional and AM-specific novel aluminum alloys, respectively, were manufactured by LPBF technique using pre-alloyed gas atomized powders. The Al-Zn-Mg ternary alloys exhibited cracks at various LPBF processing parameters, primarily along the grain boundaries of the large columnar grains that …

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Editorial: Water Environmental Research, Brooke K. Mayer Jun 2020

Editorial: Water Environmental Research, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

No abstract provided.

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Flux-Switching Permanent Magnet Machines: A Review Of Opportunities And Challenges—Part I: Fundamentals And Topologies, Hao Chen, Ayman M. El-Refaie, Nabeel A. O. Demerdash Jun 2020

Flux-Switching Permanent Magnet Machines: A Review Of Opportunities And Challenges—Part I: Fundamentals And Topologies, Hao Chen, Ayman M. El-Refaie, Nabeel A. O. Demerdash

Electrical and Computer Engineering Faculty Research and Publications

Flux-switching permanent magnet (FSPM) machines have been gaining interest over the last few decades. This is due to the several advantages that this type of machines provides. These advantages include high torque density due to the flux-focusing effects, favorable thermal management due to the location of PMs on the stator, passive and hence robust rotor structure which is suitable for high-speed applications, etc. The two-part companion articles are going to provide a comprehensive analysis of FSPM machines in terms of opportunities and challenges. In the first part of these two-part series, it covers the principle theory, computation methods, various topologies …

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An Autoencoder And Artificial Neural Network-Based Method To Estimate Parity Status Of Wild Mosquitoes From Near-Infrared Spectra, Masabho Peter Milali, Samson S. Kiware, Nicodem J. Govella, Fredros Okumu, Naveen K. Bansal, Serdar Bozdag, Jacques D. Charlwood, Marta F. Maia, Sheila B. Ogoma, Floyd E. Dowell, George Corliss, Maggy T. Sikulu-Lord, Richard J. Povinelli Jun 2020

An Autoencoder And Artificial Neural Network-Based Method To Estimate Parity Status Of Wild Mosquitoes From Near-Infrared Spectra, Masabho Peter Milali, Samson S. Kiware, Nicodem J. Govella, Fredros Okumu, Naveen K. Bansal, Serdar Bozdag, Jacques D. Charlwood, Marta F. Maia, Sheila B. Ogoma, Floyd E. Dowell, George Corliss, Maggy T. Sikulu-Lord, Richard J. Povinelli

Electrical and Computer Engineering Faculty Research and Publications

After mating, female mosquitoes need animal blood to develop their eggs. In the process of acquiring blood, they may acquire pathogens, which may cause different diseases in humans such as malaria, zika, dengue, and chikungunya. Therefore, knowing the parity status of mosquitoes is useful in control and evaluation of infectious diseases transmitted by mosquitoes, where parous mosquitoes are assumed to be potentially infectious. Ovary dissections, which are currently used to determine the parity status of mosquitoes, are very tedious and limited to few experts. An alternative to ovary dissections is near-infrared spectroscopy (NIRS), which can estimate the age in days …

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Mechanical Analysis And Modeling Of Porous Thermal Barrier Coatings, Shiyu Cui, Wenping Liang, Luis Saucedo Mora, Qiang Miao, Joseph P. Domblesky, Hao Lin, Lijia Yu May 2020

Mechanical Analysis And Modeling Of Porous Thermal Barrier Coatings, Shiyu Cui, Wenping Liang, Luis Saucedo Mora, Qiang Miao, Joseph P. Domblesky, Hao Lin, Lijia Yu

Mechanical Engineering Faculty Research and Publications

Thermal barrier coatings (TBCs) are applied to the surface of components that are used in gas turbines and aircraft engines in order to increase the heat load. In this study, the cross-sectional microstructures of TBCs were investigated via scanning electron microscopy. After calculating the porosity and the pore size distribution, a two-dimensional finite element model with four different porosities (0, 1, 3, and 5%) were established. A stochastic method was used to generate a randomly distributed porous structure. Based on the results of FE analysis and nanoindentation tests, It was found that, at a high porosity (>3%), radial cracks …

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Additive Manufacturing Of Dense We43 Mg Alloy By Laser Powder Bed Fusion, Holden Hyer, Le Zhou, George Benson, Brandon Mcwilliams, Kyu Cho, Yongho Sohn May 2020

Additive Manufacturing Of Dense We43 Mg Alloy By Laser Powder Bed Fusion, Holden Hyer, Le Zhou, George Benson, Brandon Mcwilliams, Kyu Cho, Yongho Sohn

Mechanical Engineering Faculty Research and Publications

WE43 is a high-strength, corrosion-resistant Mg-alloy containing rare earths such as Y and Nb, and has potential for many lightweight structural or bioresorbable prosthetic applications. In this study, additive manufacturing of dense WE43 alloy by laser powder bed fusion (LPBF) from gas atomized powders has been accomplished through studies involving single track scan of wrought WE43, parametric variation of LPBF, microstructural analysis and mechanical testing, both in compression and tension. The Archimedes method and image analyses from optical micrographs were employed to document the LPBF of dense (>99 % relative density) WE43 using optimum parameters of 200 W laser …

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Using Online Discussions To Connect Theory And Practice In Core Engineering Undergraduate Courses, Lisa B. Bosman, Somesh Roy, Walter M. Mcdonald, Cristinel Ababei May 2020

Using Online Discussions To Connect Theory And Practice In Core Engineering Undergraduate Courses, Lisa B. Bosman, Somesh Roy, Walter M. Mcdonald, Cristinel Ababei

Electrical and Computer Engineering Faculty Research and Publications

Providing engineering undergraduate students opportunities to connect real-world applications with theory is key to preparing them for the workforce; however, this task often requires a balancing act between meeting course objectives in content-heavy core engineering undergraduate courses and providing experiences that connect real-world applications with theory. This study seeks to address this problem through the integration of online discussion prompts to promote a connection to real-world practical applications. The study included undergraduate students enrolled in three engineering core courses. The hypothesis was that participation in online discussions (using prompts) would lead to 1) an increase in student empowerment towards self-regulated …

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Modeling And Experimental Verification Of An Unconventional 9-Phase Asymmetric Winding Pm Motor Dedicated To Electric Traction Applications, Ersin Yolacan, Mustafa K. Guven, Metin Aydin, Ayman M. El-Refaie Apr 2020

Modeling And Experimental Verification Of An Unconventional 9-Phase Asymmetric Winding Pm Motor Dedicated To Electric Traction Applications, Ersin Yolacan, Mustafa K. Guven, Metin Aydin, Ayman M. El-Refaie

Electrical and Computer Engineering Faculty Research and Publications

Multi-phase permanent magnet motors are becoming popular in various applications such as high power traction which require low cogging and torque ripple, and reduced noise and vibration. This paper presents the development process of a full order detailed mathematical model for an unconventional nine-phase permanent magnet (PM) motor with asymmetric AC windings. The phase inductances are calculated based on the individual winding functions. Using these parameters, electrical equations for each phase based on the voltages and flux linkages are generated. These equations are transformed into an arbitrary reference frame and the torque equations are developed for the 9-phase motor. A …

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The State Of Technologies And Research For Energy Recovery From Municipal Wastewater Sludge And Biosolids, Zhongzhe Liu, Brooke K. Mayer, Kaushik Venkiteshwaran, Saba Seyedi, Arun S.K. Raju, Daniel Zitomer, Patrick J. Mcnamara Apr 2020

The State Of Technologies And Research For Energy Recovery From Municipal Wastewater Sludge And Biosolids, Zhongzhe Liu, Brooke K. Mayer, Kaushik Venkiteshwaran, Saba Seyedi, Arun S.K. Raju, Daniel Zitomer, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Wastewater resource recovery facilities produce wastewater solids that offer potential for energy recovery. This opinion article provides a perspective on state-of-the-art technologies to recover energy from sludge (unstabilized wastewater residual solids) and biosolids (stabilized wastewater solids meeting criteria for application on land). The production of biodiesel fuel is an emerging technology for energy recovery from sludge, whereas advancements in pretreatment technologies have improved energy recovery from anaerobic digestion of sludge. Incineration is an established technology to recover energy from sludge or biosolids. Gasification, and to a greater extent, pyrolysis are emerging technologies well-suited for energy recovery from biosolids. While gasification …

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Inelastic Behavior And Seismic Design Of Multistory Chevron-Braced Frames With Yielding Beams, Charles W. Roeder, Andrew D. Sen, Hayato Asada, Sara M. Ibarra, Dawn E. Lehman, Jeffrey W. Berman, Keh-Chyuan Tsai, Ching-Yi Tsai, An-Chien Wu, Kung-Juin Wang, Ruyue Liu Apr 2020

Inelastic Behavior And Seismic Design Of Multistory Chevron-Braced Frames With Yielding Beams, Charles W. Roeder, Andrew D. Sen, Hayato Asada, Sara M. Ibarra, Dawn E. Lehman, Jeffrey W. Berman, Keh-Chyuan Tsai, Ching-Yi Tsai, An-Chien Wu, Kung-Juin Wang, Ruyue Liu

Civil and Environmental Engineering Faculty Research and Publications

Chevron or inverted V-braced frames offer numerous architectural and structural advantages, but the current special concentrically braced frame (SCBF) seismic-design requirements in the American Institute of Steel Construction (AISC) Seismic Provisions for Structural Steel Buildings lead to deep, heavy chevron beams; as a result, few chevron SCBFs are built today. Recent research on single-story chevron SCBFs demonstrated that beam yielding can be advantageous at higher demand levels, and design for large, inelastic unbalanced brace-force demands may still result in acceptable seismic performance. However, this prior research did not consider the response of multistory frames. In particular, questions remain as to …

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Monitoring Hydrologic Controls On Biogeochemical Process Variability In Green Infrastructure Soils, Laine Pulvermacher Apr 2020

Monitoring Hydrologic Controls On Biogeochemical Process Variability In Green Infrastructure Soils, Laine Pulvermacher

Master's Theses (2009 -)

The premise of this research was to monitor biogeochemical responses to soil moisture and soil temperature within green stormwater infrastructure soils. Adopting best management practices like green infrastructure in urban areas has the potential to remove incoming nutrients from stormwater runoff through biogeochemical processes, like plant and microbial metabolism. Biogeochemical activity has been suggested to be highly variable, so this research proposed to monitor that variability by tracking the stoichiometry of soil respiration. Additionally, an advection-diffusion-reaction model was used to disaggregate physical and biogeochemical controls on the observed soil respiration. The field data was collected to investigate the biogeochemical processes, …

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