Engineering Commons^™

An Efficient Mode-Based Domain Decomposition Hybrid 2-D/Q-2d Finite-Element Time-Domain Method For Power/Ground Plate-Pair Analysis, Ping Li, Li (Lijun) Jun Jiang, Yao Jiang Zhang, Shuai Xu, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

Generally, with a surface magnetic current excitation, only the TM zmn modes are activated between the power/ground plate pair. As a result, the magnetic field only has azimuthal component while the longitude component is zero. To make full use of this quasi-2-D (Q-2D) property, a Q-2D finite-element time-domain (FETD) method combined with the basic 3-D triangular prism mesh elements is firstly proposed to solve the magnetic field wave equation. It is further noted that the higher order modes are confined in the proximity of the antipads (labeled as via domain) due to the exponential attenuation property along the propagating direction. …

Study Of Cost Overrun And Delays Of Department Of Defense (Dod)'S Space Acquisition Program, Nazareen Sikkandar Basha, Benjamin J. Kwasa, Christina Bloebaum

Engineering Management and Systems Engineering Faculty Research & Creative Works

Defense and Aerospace Systems Acquisition projects, just like any other Large-Scale Complex Engineered Systems (LSCES) experience delays and cost overrun during the acquisition process. Cost overrun and delays in LSCES are due, in part, to high complexity, size of the project, involvement of various stakeholders, organizations, political disruptions, changes in requirements and scope. These uncertainties, due to the exogenous factors, have cost the federal government billions of dollars and delays in completion of the programs. Cost estimation of federal programs is usually based on previous generations of systems produced and almost all the time the costs are underestimated. Underestimation of …

Circuitry Design And Magnetic Susceptibility Evaluation Of 7t Fmri Implantable Rf Coil, Rong Wang, Celia M. Dong, Ed X. Wu, Robert C. Roberts, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Implantable coils have been widely utilized in functional magnetic resonance imaging (fMRI) owing to their superior signal to noise ratio. To effectively minimize the magnetic field distortion and image artifacts, the magnetic susceptibility of the implantable coil needs to be evaluated before practical use. In this work, we experimentally identify the magnetic susceptibility of each component of the implantable coil with the 7T Bruker NMR imaging scanner and provide useful guidelines for the following manufacturing. A 5 5 mm 2 implantable surface coil with a tunable frequency range is subsequently introduced for the 7T fMRI of the rat primary somatosensory …

Rare Earth Elements Removal Techniques From Water/Wastewater: A Review, Omoniyi Pereao, Chris Bode-Aluko, Olanrewaju Fatoba, Katri Laatikainen, Leslie Petrik

Mining Engineering Faculty Research & Creative Works

The rare-earth elements (REEs) remain very important due to the growing increase in their demand and for their critical and indispensable use in many high-tech industries today. This growing demand for REEs has led to an increased environmental exposure and water pollution from numerous REEs commercial products and as a result, the recovery of REEs is a significant issue that requires appropriate consideration. There are diverse and various strategic techniques available to remove metal ions from aqueous solutions, but nanofiber adsorbent appears to be quite innovative due to their outstanding characteristics such as cost effectiveness, flexibility, high surface area, porosity, …

Impulsive Dynamics And Control Of The Inertia-Wheel Pendulum, Nilay Kant, Ranjan Mukherjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The dynamics of the inertia-wheel pendulum, when subjected to impulsive inputs, can be described by algebraic equations. Optimal sequences of these inputs, that minimize their infinity norm, are designed for rest-to-rest maneuvers. The results are applied to the well-studied swing-up problem, and high-gain feedback is used for continuous approximation of the inputs and simulation of the impulsive dynamics. Analytical and simulation results establish a direct link between high wheel velocities during swing-up and control strategies that take the pendulum directly to the upright configuration. They also indicate that optimal trajectories resemble those of energy-based controllers and can be designed to …

Revealing Particle-Scale Powder Spreading Dynamics In Powder-Bed-Based Additive Manufacturing Process By High-Speed X-Ray Imaging, Luis I. Escano, Niranjan D. Parab, Lianghua Xiong, Qilin Guo, Cang Zhao, Kamel Fezzaa, Wes Everhart, Tao Sun, Lianyi Chen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Powder spreading is a key step in the powder-bed-based additive manufacturing process, which determines the quality of the powder bed and, consequently, affects the quality of the manufactured part. However, powder spreading behavior under additive manufacturing condition is still not clear, largely because of the lack of particle-scale experimental study. Here, we studied particle-scale powder dynamics during the powder spreading process by using in-situ high-speed high-energy x-ray imaging. Evolution of the repose angle, slope surface speed, slope surface roughness, and the dynamics of powder clusters at the powder front were revealed and quantified. Interactions of the individual metal powders, with …

Comparison Of Salicyl Hydroxamate Adsorption On Rare Earth Phosphates To Oxides And Carbonates, Stephanie Trant

Graduate Theses & Non-Theses

Adsorption behavior of the anionic collector salicyl hydroxamic acid (SHA) on a group of selected rare earth phosphates (REPs) was studied by means of experimental methods and modeling software. These REPs were then compared to rare earth carbonates (RECs) and rare earth oxides (REOs) to develop a trend. A suite of rare earth elements (REE) were studied that included light (LREE) and middle (MREE). Results for heavy (HREE) were inferred. Synthetic phosphate, oxide and carbonate powders of the rare earth elements Lanthanum (La), Cerium (Ce), Europium (Eu) and Dysprosium (Dy) were tested for these studies. Dysprosium phosphate was the only …

Pneumatospinning Of Collagen Microfibers From Benign Solvents, Seth Polk, Nardos Sori, Nick Thayer, Yas Maghdouri-White, Anna A. Bulysheva, Michael P. Francis

School of Medical Diagnostics & Translational Sciences Publications

Introduction. Current collagen fiber manufacturing methods for biomedical applications, such as electrospinning and extrusion, have had limited success in clinical translation, partially due to scalability, cost, and complexity challenges. Here we explore an alternative, simplified and scalable collagen fiber formation method, termed 'pneumatospinning,' to generate submicron collagen fibers from benign solvents. Methods and results. Clinical grade type I atelocollagen from calf corium was electrospun or pneumatospun as sheets of aligned and isotropic fibrous scaffolds. Following crosslinking with genipin, the collagen scaffolds were stable in media for over a month. Pneumatospun collagen samples were characterized using Fourier-transform infrared spectroscopy, circular dichroism, …

Indirect Imaging Using Computational Imaging Techniques, Aparna Viswanath

Electrical Engineering Theses and Dissertations

The work describes various methods employed towards solving the problem of indirect imaging. Computational techniques are employed to indirectly decipher information about an object hidden from view of a camera. Notion of virtualizing the source of illumination and detectors on real world rough surfaces was exploited to construct a non line of sight computational imager. Diversity was explored from the stand point of both illumination of the object and imaging of light reflected from the object. To understand the impact of scattering by real world rough surfaces, an instrument was developed that allows characterization of isoplanatic angle for different surface …

Molecular Dynamics Studies On Nanoscale Confined Liquids, Alper Celebi

Mechanical Engineering Research Theses and Dissertations

Liquid transport in nanochannels have been attracting great interests, especially for last two decades, owing to its potential applicability in various fields including biochemistry, medical science and engineering. For exploring and generating new ideas in the field of nanofluidics, molecular simulation techniques have become an ideal way due to the experimental challenges impeding the field of nanofluidics in fabrication and measurements.

In this dissertation, we perform molecular dynamics simulations to investigate liquid transport behavior in nanoscale channels. The expanse of this dissertation concerns several fundamental topics in nanoscale liquid transport phenomena such as liquid properties in nanoscale confinements, interfacial flows …

No2- And No3- Enhance Cold Atmospheric Plasma Induced Cancer Cell Death By Generation Of Onoo-, Dehui Xu, Qingjie Cui, Yujing Xu, Zhijie Liu, Zeyu Chen, Wenjie Xia, Hao Zhang, Dingxin Liu, Hailan Chen, Michael G. Kong

Bioelectrics Publications

Cold atmospheric plasma (CAP) is a rapidly developed technology that has been widely applied in biomedicine especially in cancer treatment. Due to the generation of various active species in plasma, CAP could induce various tumor cells death and showed a promising potential in cancer therapy. To enhance the biological effects of gas plasma, changing the discharging parameters is the most commonly used method, yet increasing discharging power will lead to a higher possibility of simultaneously damage surrounding tissues. In this study, by adding nontoxic concentration of additional nitrite and nitrate in the medium, we found that anti-tumor effect of CAP …

Flexural Rigidity Estimation Using Noisy Static Influence Lines, Yasha Hajizeinalibiouki

Civil and Environmental Engineering Theses and Dissertations

Society depends on critical infrastructure to support everyday activities. Even as critical components of civil infrastructure approach and exceed their design lives, demand on these structures continues to increase. In light of the need for managing aging infrastructure, several opportunities exist for research that can aid infrastructure managers in significant the challenge of detecting, classifying, and mitigating structural impairments. This dissertation presents a novel framework for impairment detection through the capture and utilization of deformation influence lines for flexural rigidity estimation on Euler-Bernoulli beams. In this research study, mechanical theory, a computer-vision algorithm, and multiple numerical methods are integrated to …

Thermal Bridging In Concrete Sandwich Walls, Taylor J. Sorensen, Robert J. Thomas, Sattar Dorafshan, Marc Maguire

Faculty Publications

Energy efficiency requires continuity of the insulation system in structural and architectural details.

Visforum: A Visual Analysis System For Exploring User Groups In Online Forums, Siwei Fu, Yong Wang, Yi Yang, Qingqing Bi, Fangzhou Guo, Huamin Qu

Research Collection School Of Computing and Information Systems

User grouping in asynchronous online forums is a common phenomenon nowadays. People with similar backgrounds or shared interests like to get together in group discussions. As tens of thousands of archived conversational posts accumulate, challenges emerge for forum administrators and analysts to effectively explore user groups in large-volume threads and gain meaningful insights into the hierarchical discussions. Identifying and comparing groups in discussion threads are nontrivial, since the number of users and posts increases with time and noises may hamper the detection of user groups. Researchers in data mining fields have proposed a large body of algorithms to explore user …

Treatment Of Disperse Blue 14 Wastewater And Sugar Wastewater By Low Cost Adsorbents, Saisantosh Vamshi Harsha Madiraju, Yung-Tse Hung, Howard H. Paul

Civil and Environmental Engineering Faculty Publications

Orange peel and Peanut hull are used in this research to treat the combined binary mixture of Disperse Blue 14and sugar wastewater. The combined wastewater is treated with adsorption followed by micro-filtration. The dosages, sizes and concentrations used in this research are based on trail and error method. Whatman-41 is used in the micro-filtration treatment process. This research is mainly based on color removal. The color removal is estimated and compared from the measured transmittance and absorbance values. The same treatment tests are performed on the activated carbon and taken as datum and compared with the low-cost adsorbents. NPOC values …

Prediction And Rehabilitation Of Highway Embankment Slope Failures In Changing Climate, Navid Jafari, Anand Puppala

Publications

Highway slopes constructed with clayey soil are prone to desiccation cracks due to wetting and drying weather cycle, which allows greater moisture infiltration into the embankment from precipitation. Fissures formed due to extended wetting and drying cycles allow water to seep deeper into the soil than surficial wetting and increase the water content. This increases the moisture content in the soil and results in reduction in shear strength to the fully softened strength. On the other hand, development of desiccation cracks and reduction of the soil matric suction ultimately result in higher hydraulic conductivity value which causes development of higher …

Impacts Of Moisture On Asphalt Properties, Zahid Hossain

Publications

Stripping related moisture damage has been recognized as one of the major pavement distresses since the early 1990s. The main objective of this study is to establish an effective test protocol to quantify moisture susceptibility of asphalt pavements. To this end, selective test methods (Texas Boiling test, Tensile Strength Ratio, Retained Stability, and Hamburg Wheel Test), and procedures based on surface chemistries and molecular-level mechanistic properties have been investigated in this study. Firstly, a comprehensive list of literature related to moisture damage in asphalts was reviewed. Based on the literature review, a detailed project plan and test matrix were developed. …

The Professional Constructor, Full Issue, Volume 43, Number 02

The Professional Constructor

No abstract provided.

Ion-Sensitive Field-Effect Transistors With Micropillared Gates For Measuring Cell Ion Exchange At Molecular Levels, Mohammad G. Abdallah, Rayan Khan, Christian Garcia, Young-Tae Kim, Samir M. Iqbal

Electrical and Computer Engineering Faculty Publications

The detection of small concentrations of cancer cells before cancer takes over the primary organ completely, or metastasizes to other areas of the body is important for early screening of cancer. One approach to address cancer early screening is through cell ion exchange bioelectricity, which characterizes voltage potential in non-neuronal cells to regulate shape changing, proliferation, differentiation, migration, and cancer formation. Herein, novel ion-sensitive field-effective transistor (ISFET) modality is shown to measure cell behavior during the change of cell properties at molecular levels. ISFETs produce low resistance signals and consume low power. The small size of ISFETs enables miniature diagnosis …

Impact Of Communication Latency On The Bus Voltage Of Centrally Controlled Dc Microgrid During Islanding, Mahmoud Saleh, Yusef Esa, Ahmed Mohamed

Publications and Research

Maintaining a sustainable and reliable source of energy to supply critical loads within a renewable energy based microgrid (MG) during blackouts is directly related to its bus voltage variations. For example, voltage variation might trigger protection devices and disconnect DERs within the MG. Centrally controlled MGs (CCMGs) type is dependent on communication. Therefore, it is very important to analyze the impact of communication networks performance degradation, such as latency, on the bus voltage of CCMGs. This paper investigates the effect of wireless communication technologies latency on the bus voltage and performance of centralized DC MGs. Two mathematical models were developed …

Pick And Place Bot: Asme Design Challenge, Steven Mumford, Josh Clark, Stephan Meyer

Mechanical Engineering Design Project Class

Design a bot that meets the standards of and is able to compete in the 2019 ASME Design Challenge.

Group B: Polar Coordinate Whiteboard Writer, Dylan Wu, Zexin Han, Keon Kim, Jiahao Wei

Mechanical Engineering Design Project Class

From the initial funding of $250.00, our group attempted to make a polar coordinate whiteboard writer that was to be used in educational settings. Market for polar coordinate whiteboard writer is a blue ocean. Having a successful prototype will allow us to find a niche place in a market that shares border with the global education market.

Group V: Color Mixer, Kate Baskin, Mark Livshin, Andy Johnston

Mechanical Engineering Design Project Class

This project was an exercise in product design, modeling, and prototyping. The result of this process was a partially functional prototype which successfully met two of the three design goals.

Group L: T-Shirt2 Cutter, Sophie Anderson, Avery German, Taylor Tuleja

Mechanical Engineering Design Project Class

The T-shirt square cutter was commissioned by fashion design professor at Washington University, Dr. Mary RuppertStroescu who has developed a method of turning T-shirts that might have otherwise been thrown away into a unique, woven fabric. Dr. Ruppert-Stroescu cuts T-shirts into either strips or squares that she then quilts together, she uses this fabric to make one-of-a-kind clothes, bags, and rugs. Though she is proficient at weaving the fabric scraps together, cutting the Tshirts was a very time-consuming process – it takes her at least 20 minutes to cut a T-shirt into squares by hand. Our team was tasked with …

Autonomous Ground Photographer, Sylvia Tan, Nicholas C. Smith, Kate Padilla, Elise Ashley

Mechanical Engineering Design Project Class

Dr. Penczykowski, a biology professor at Washington University in St. Louis, researches the effects of powdery mildew on three plant species. Her lab currently collects data in the field by manually counting the number of infected plants with the assistance of a simple PVC grid. Therefore, this projects aims to automate this process by capturing images that can then be processed in her lab after.

Group T Asme Design Challenge Project, Thomas Orgielewicz, Hayden Von Hoffmann, Michael Chirumbole

Mechanical Engineering Design Project Class

Design and build a RC Robot eligible to compete in the 2019 ASME Challenge, the "Pick-and-Place Race"

Tendon Rehabilitator, David Ricks, Lucas Parisot, Benjamin Wang

Mechanical Engineering Design Project Class

Our goal was to provide a cheap, portable and easy way for those suffering from medial epicondylitis tendinosis, or golfers elbow, to perform rehabbing exercises.

Comparison Of Deep Convolutional Neural Networks And Edge Detectors For Image-Based Crack Detection In Concrete, Sattar Dorafshan, Robert J. Thomas, Marc Maguire

Civil Engineering Faculty Publications

This paper compares the performance of common edge detectors and deep convolutional neural networks (DCNN) for image-based crack detection in concrete structures. A dataset of 19 high definition images (3420 sub-images, 319 with cracks and 3101 without) of concrete is analyzed using six common edge detection schemes (Roberts, Prewitt, Sobel, Laplacian of Gaussian, Butterworth, and Gaussian) and using the AlexNet DCNN architecture in fully trained, transfer learning, and classifier modes. The relative performance of each crack detection method is compared here for the first time on a single dataset. Edge detection methods accurately detected 53–79% of cracked pixels, but they …

Sh-Mode Seismic-Reflection Imaging Of Earthfill Dams, Edward W. Woolery

Earth and Environmental Sciences Faculty Publications

Assessing subsurface characteristics and imaging geologic features (e.g., faults, cavities, low-velocity layers, etc.) are typical problems in near-surface geophysics. These questions often have adverse geotechnical engineering implications, and can be especially acute when associated with high-hazard structures such as large earthen flood-control dams. Dam-related issues are becoming more frequent in the United States, because a large part of this major infrastructure was designed and constructed in the early- to mid-twentieth century; these dams are thus passing into the latter stages of their design life, where minute flaws that were overlooked or thought to be insignificant in design/construction are now …

Effects Of Nearwall Modeling In The Improved-Delayed-Detached-Eddy-Simulation (Iddes) Methodology, Rohit Saini, Nader Karimi, Lian Duan, Amsini Sadiki, Amirfarhang Mehdizadeh

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The present study aims to assess the effects of two different underlying RANS models on overall behavior of the IDDES methodology when applied to different flow configurations ranging from fully attached (plane channel flow) to separated flows (periodic hill flow). This includes investigating prediction accuracy of first and second order statistics, response to grid refinement, grey area dynamics and triggering mechanism. Further, several criteria have been investigated to assess reliability and quality of the methodology when operating in scale resolving mode. It turns out that irrespective of the near wall modeling strategy, the IDDES methodology does not satisfy all criteria …