Engineering Commons^™

Review: Biological Engineering For Nature-Based Climate Solutions, Benjamin R. K. Runkle

Biological and Agricultural Engineering Faculty Publications and Presentations

Nature-based Climate Solutions are landscape stewardship techniques to reduce greenhouse gas emissions and increase soil or biomass carbon sequestration. These mitigation approaches to climate change present an opportunity to supplement energy sector decarbonization and provide co-benefits in terms of ecosystem services and landscape productivity. The biological engineering profession must be involved in the research and implementation of these solutions—developing new tools to aid in decision-making, methods to optimize across different objectives, and new messaging frameworks to assist in prioritizing among different options. Furthermore, the biological engineering curriculum should be redesigned to reflect the needs of carbon-based landscape management. While doing …

Tools & Visualization Techniques Available To Support The Operations Manager, Kirk Michealson

Operations Management Presentations

Most organizations provide their employees the Microsoft Office Tools Suite with Excel. The University of Arkansas Master of Science in Operations Management (MSOM) Program has included Excel as a foundational aspect of the program for the last 7 years. In that time, Microsoft has increased the Excel capabilities dramatically. Simultaneously, business intelligence analytics interest has increased, and Tableau has been created as a visual analytics platform to help users see and understand data for modern business intelligence. As a result, to support the Operations Manager the MSOM Program has developed a new course to present the additional tools and visualization …

Water Quality Concentration Trends And Loads Identify Management Needs In The Lake Wister Watershed, Abbie L. Lasater, Brian Haggard

Biological and Agricultural Engineering Faculty Publications and Presentations

Trend analyses of water quality seek to determine whether concentrations of constituents have increased or decreased over time, which can show the effectiveness of management practices or the need for pollutant reduction. The Poteau River watershed (PRW) is a transboundary watershed across Arkansas and Oklahoma and, in Arkansas, has been listed as a priority watershed within the Arkansas Nonpoint Source Pollution Plan since 1998. The Poteau River, Black Fork, and Fourche Maline within the PRW flow into Lake Wister, which is an important reservoir for recreation, fishing, and waterfowl hunting for residents and tourists around eastern Oklahoma. The purpose of …

Anesthetics Affect Peripheral Venous Pressure Waveforms And The Cross-Talk With Arterial Pressure, Ali Z. Al-Alawi, Kaylee R. Henry, Lauren D. Crimmins, Patrick C. Bonasso, Md Abul Hayat, Melvin S. Dassinger, Jeffrey M. Burford, Hanna K. Jensen, Joseph Sanford, Jingxian Wu, Kevin W. Sexton, Morten O. Jensen

Biomedical Engineering Faculty Publications and Presentations

Analysis of peripheral venous pressure (PVP) waveforms is a novel method of monitoring intravascular volume. Two pediatric cohorts were studied to test the effect of anesthetic agents on the PVP waveform and cross-talk between peripheral veins and arteries: (1) dehydration setting in a pyloromyotomy using the infused anesthetic propofol and (2) hemorrhage setting during elective surgery for craniosynostosis with the inhaled anesthetic isoflurane. PVP waveforms were collected from 39 patients that received propofol and 9 that received isoflurane. A multiple analysis of variance test determined if anesthetics influence the PVP waveform. A prediction system was built using k-nearest neighbor (k-NN) …

Development Of Custom Wall-Less Cardiovascular Flow Phantoms With Tissue-Mimicking Gel, Megan Laughlin, Sam E. Stephens, Jamie A. Hestekin, Morten O. Jensen

Biomedical Engineering Faculty Publications and Presentations

Purpose

Flow phantoms are used in experimental settings to aid in the simulation of blood flow. Custom geometries are available, but current phantom materials present issues with degradability and/or mimicking the mechanical properties of human tissue. In this study, a method of fabricating custom wall-less flow phantoms from a tissue-mimicking gel using 3D printed inserts is developed.

Methods

A 3D blood vessel geometry example of a bifurcated artery model was 3D printed in polyvinyl alcohol, embedded in tissue-mimicking gel, and subsequently dissolved to create a phantom. Uniaxial compression testing was performed to determine the Young’s moduli of the five gel …

Design And Optimization Of High Temperature Optocouplers As Galvanic Isolation, Abbas Sabbar, Syam Madhusoodhanan, Huong Tran, Binzhong Dong, Jiangbo Wang, H. Alan Mantooth, Shui-Qing Yu, Zhong Chen

Electrical Engineering Faculty Publications and Presentations

The commercial InGaN-based (blue and green) and AlGaInP-based (red) multiple quantum well (MQW) lighting emitting diodes (LEDs) were studied in a wide range of temperatures up to 800 K for their light emission and detection (i.e., LEDs operated under reverse bias as photodiodes (PDs)) characteristics. The results indicate the feasibility of integrating a pair of selected LEDs to fabricate high temperature (HT) optocouplers, which can be utilized as galvanic isolation to replace the bulky isolation transforms in the high-density power modules. A detailed study on LEDs and PDs were performed. The external quantum efficiency (EQE) of the LED and PDs …

High-Temperature Analysis Of Optical Coupling Using Algaas/Gaas Leds For High-Density Integrated Power Modules, Syam Madhusoodhanan, Abbas Sabbar, Huong Tran, Pengyu Lai, David Gonzalez, H. Alan Mantooth, Shui-Qing Yu, Zhong Chen

Electrical Engineering Faculty Publications and Presentations

A low-temperature co-fired ceramic (LTCC)-based optocoupler design is demonstrated as a possible solution for optical isolation in high-density integrated power modules. The design and fabrication of LTCC based package are discussed. Commercially available aluminum gallium arsenide/gallium arsenide (AlGaAs/GaAs) double heterostructure is used both as emitter and photodetector in the proposed optocoupler. A detailed study on the electroluminescence and spectral response of the AlGaAs/GaAs structure is conducted at elevated temperatures. The material figure of merit parameter, D*, is calculated in the temperature range 77-800 K. The fabricated optocoupler is tested at elevated temperatures, and the results are presented.

Low-Cost Solar Collectors To Pre-Heat Ventilation Air In Broiler Houses, Yi Liang, Michael Janorschke, Chad E. Hayes

Biological and Agricultural Engineering Faculty Publications and Presentations

The objective of the study was to evaluate the effect of a low-cost solar collector to pre-heat ventilation air in commercial broiler buildings on supplemental heating demand and air quality during the cold season. Six black fabric-based solar collectors of 36 m(2) each were installed on the south-facing rooftop of a broiler house. The solar collectors provided fresh warm air into the house during the ON cycle of minimum ventilation and during the OFF cycle of minimum ventilation when the temperature under the collectors met certain criteria. The daily cumulative duration of solar collectors in operation averaged 125 and 133 …

In Vitro Mitral Valve Model With Unrestricted Ventricular Access: Using Vacuum To Close The Valve And Enable Static Trans-Mitral Pressure, Sam E. Stephens, Alexander J. Kammien, Jacob C. Paris, Alexis P. Applequist, Neil B. Ingels, Hanna K. Jensen, Drew E. Rodgers, Charles R. Cole, Jonathan F. Wenk, Morten O. Jensen

Biomedical Engineering Faculty Publications and Presentations

Current in vitro models of the left heart establish the pressure difference required to close the mitral valve by sealing and pressurizing the ventricular side of the valve, limiting important access to the subvalvular apparatus. This paper describes and evaluates a system that establishes physiological pressure differences across the valve using vacuum on the atrial side. The subvalvular apparatus is open to atmospheric pressure and accessible by tools and sensors, establishing a novel technique for experimentation on atrioventricular valves. Porcine mitral valves were excised and closed by vacuum within the atrial chamber. Images were used to document and analyze closure …

Regularizing The Deepsurv Network Using Projection Loss For Medical Risk Assessment, Phawis Thammasorn, Stephanie K. Schaub, Daniel S. Hippe, Matthew B. Spraker, Jan C. Peeken, Landon S. Wootton

Industrial Engineering Faculty Publications and Presentations

State-of-the-art deep survival prediction approaches expand network parameters to accommodate performance over a fine discretization of output time. For medical applications where data are limited, the regression-based Deepsurv approach is more advantageous because its continuous output design limits unnecessary network parameters. Despite the practical advantage, the typical network lacks control over the feature distribution causing the network to be more prone to noisy information and occasional poor prediction performance. We propose a novel projection loss as a regularizing objective to improve the time-to-event Deepsurv model. The loss formulation maximizes the lower bound of the multiple-correlation coefficient between the network’s features …

Removal Of Emerging Contaminants From Wastewater Streams Using Membrane Bioreactors: A Review, Arijit Sengupta, Mahmood Jebur, Mohanad Kamaz, Sumith R. Wickramasinghe

Chemical Engineering Faculty Publications and Presentations

Water is a very valuable natural resource. As the demand for water increases the presence of emerging contaminants in wastewater has become a growing concern. This is particularly true when one considers direct reuse of wastewater. Obtaining sufficient removal of emerging contaminants will require determining the level of removal for the various unit operations in the wastewater treatment process. Membrane bioreactors are attractive as they combine an activated sludge process with a membrane separation step. They are frequently used in a wastewater treatment process and can operate at higher solid loadings than conventional activated sludge processes. Determining the level of …

Analytical And Experimental Investigation Into Pre-Stressed Carbon Fiber Reinforced Polymer (Cfrp) Fatigue Retrofits For Steel Waterway Lock-Gate Structures, Christina Lozano, Maggie Langston, Mohammad H. Kashefizadeh, Gary S. Prinz

Civil Engineering Faculty Publications and Presentations

Lock gates are an important part of the transportation infrastructure within the United States (US). Unfortunately, many existing lock gates have reached or exceeded their initial design lives and require frequent repairs to remain in service. Unscheduled repairs often increase as gates age, having a local economic impact on freight transport, which can create economic ripples throughout the nation. Metal fatigue is a key cause of unscheduled service interruptions, degrading lock gate components over time. Additionally, because lock gates are submerged during operation, crack detection prior to component failure can be difficult, and repair costs can be high. This paper …

Academy Presidents And Institutional Members, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Table Of Contents, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Seasonal Testicular Histology And Acystic Lobular Spermatogenesis In The Western Lesser Siren, Siren Intermedia Nettingi (Caudata: Sirenidae), Stanley E. Trauth

Journal of the Arkansas Academy of Science

I investigated the seasonal testicular histology and acystic lobular spermatogenesis in the Western Lesser Siren, Siren intermedia nettingi, from periodic sampling of this salamander over a span of 21 yr (1994-2015) in northeastern Arkansas. My results include the following general findings: 1) the largest testicular lobules occurred primarily in January-February during spermiogenesis and spermatozoa maturation; 2) lobular regression and spermatogenic cell recrudescence were underway by late March; 3) proliferation of secondary spermatogonia in lobules was prominent in May; 4) transformation of secondary spermatogonia into primary spermatocytes occurred by mid-July, and these cells became larger in diameter through increased nuclear …

Journal Of The Arkansas Academy Of Science - Volume 76, 2022, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Distal Urogenital Anatomy In The Male Wood Frog, Lithobates Sylvaticus (Anura: Ranidae), Stanley E. Trauth

Journal of the Arkansas Academy of Science

I investigated the microanatomy of the distal urogenital system of the male Wood Frog (Lithobates sylvaticus) from a small sample (n = 6) collected in northern Arkansas in February 2020. Specifically, my primary objectives were as follows: 1) to focus on the histology of the paired Wolffian (urogenital) ducts caudally from the kidneys to their merging with the urodeum of the cloaca, 2) to reveal the structure of the paired seminal vesicles (sperm storage structures), and 3) to compare epithelial morphologies between the distal urogenital tract and its neighboring distal alimentary tract. This information will promote a clearer …

Business Meeting Report (Secretary's And Treasurer's Report), Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Instructions To Authors, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Modular Expandable Multiinput Multioutput (Mimo) High Step-Up Transformerless Dc-Dc Converter, Zahra Saadatizadeh, Pedram Chavoshipour Heris, H. Alan Mantooth

Electrical Engineering Faculty Publications and Presentations

In this paper, a Multi-Input Multi-Output (MIMO) high step-up transformerless DC-DC converter is proposed. The proposed converter can expand the number of ports from both input and output terminals. Also, it has a modular structure using voltage multiplier cells (a switch, two diodes, a capacitor, and an inductor). The proposed converter is useful for a wide range of applications and has the merit of interfacing multiple hybrid voltage sources with each other to supply different loads with various voltage levels. All the output voltages of the output ports can be regulated at the same time by tuning separate controlling parameters. …

An Efficient Electro-Thermal Compact Mode Of Sic Power Mosfets Including Third Quadrant Behavior, Arman Ur Rashid, Md Maksudul Hossain, Yuheng Wu, Hayden Seth Carlton, H. Alan Mantooth, Britt Brooks

Electrical Engineering Faculty Publications and Presentations

This paper presents an efficient physics-based electro-thermal model that solves some advanced problems of modeling Silicon Carbide (SiC) power MOSFETs. It is the first electro-thermal model that simulates the temperature dependency of the first and the third quadrant characteristics, including the reverse recovery of the body diode accurately and efficiently. It extends from a previous work that demonstrated the isothermal physics-based model of the gate-dependent body diode. Physics-based temperature scaling of the first and third quadrant allows simulation of the self-heating effect in a wide range of temperatures (27 °C–200 °C), even for the synchronous operation. Moreover, a physics-based modeling …

Power Relay Based Multiple Device Cryogenic Characterization Method And Results, Yuqi Wei, Maksudul Hossain, Dereje Woldegiorgis, Xia Du, H. Alan Mantooth

Electrical Engineering Faculty Publications and Presentations

Cryogenic power electronics is a promising technology due to their high efficiency and high power density characteristics. As the key element of power electronic systems, semiconductor performance should be evaluated under cryogenic temperatures. Liquid nitrogen or liquid helium are usually adopted to achieve cryogenic temperatures. Traditionally, only one semiconductor can be evaluated at one time under different temperatures, which is time-consuming and not energy-friendly. To enable multiple-device characterization at one time under different temperatures, a novel power relay based characterization circuit and corresponding control strategy are described. With the aid of the proposed circuit, multiple devices can be characterized by …

Cradle-To-Grave Life Cycle Assessment Of Production And Consumption Of Pulses In The United States, Prathamesh A. Bandekar, Ben Putman, Greg Thoma, Marty Matlock

Biological and Agricultural Engineering Faculty Publications and Presentations

Environmental impact associated with production and consumption of pulses in the United States was evaluated using life cycle assessment (LCA). The system boundary was set to cradle-to-grave with a functional unit of 60 g (dry basis) of pulses consumed in a US household. Varieties of pulses modeled in the study included field pea (Pisum sativum), lentil (Lens culinaris), chickpea (Cicer arietinum), and dry bean. Three methods of cooking pulses at the consumer stage tested in the study were cooking in open vessel on electric cooking range (OVC), cooking in stovetop pressure cooker on electric cooking range (SPC), and cooking in …

Minimally Invasive In Vivo Endoscopic Monitoring Of Dextran Sulfate Sodium-Induced Murine Colitis, Elizabeth A. Bullard, Ariel I. Mundo, Shelby N. Bess, Kathryn Miller Priest, Timothy J. Muldoon

Biomedical Engineering Faculty Publications and Presentations

Ulcerative colitis (UC) is a gastrointestinal, autoimmune disease that causes ulceration and inflammation of the colon with an incidence of 10 out of every 100,000 people in North America and Western Europe. Though the specific cause is unknown, several studies have demonstrated that inflammatory cells as well as environmental variables, genetics, and lifestyle behaviors can play a role in the long-term inflammatory response. Researchers have commonly used immunohistochemistry, western blotting and gene sequencing to establish the cellular processes behind UC relapse and remission. However, because these destructive methods necessitate the removal of a sample, they can only be used on …

Immunomodulatory Functions Of Human Mesenchymal Stromal Cells Are Enhanced When Cultured On Hep/Col Multilayers Supplemented With Interferon-Gamma, Mahsa Letter-Mahsa Haseli, David A. Castilla-Casadiego, Luis Carlos Pinzon-Herrera, Alexander Hillsley, Katherine A. Miranda-Munoz, Srikanth Sivaraman, Adrianne M. Rosales, Raj R. Rao, Jorge Almodovar

Chemical Engineering Faculty Publications and Presentations

Human mesenchymal stromal cells (hMSCs) are multipotent cells that have been proposed for cell therapies due to their immunosuppressive capacity that can be enhanced in the presence of interferon-gamma (IFN-γ). In this study, multilayers of heparin (HEP) and collagen (COL) (HEP/COL) were used as a bioactive surface to enhance the immunomodulatory activity of hMSCs using soluble IFN-γ. Multilayers were formed, via layer-by-layer assembly, varying the final layer between COL and HEP and supplemented with IFN-γ in the culture medium. We evaluated the viability, adhesion, real-time growth, differentiation, and immunomodulatory activity of hMSCs on (HEP/COL) multilayers. HMSCs viability, adhesion, and growth …

Global Modeling Of Millimeter-Wave Transistors: Analysis Of Electromagnetic-Wave Propagation Effects, Soheil Nouri, Samir M. El-Ghazaly

Electrical Engineering Faculty Publications and Presentations

In this study, the transmission line concept and the electron transport theory are consolidated in a global modeling approach, the wave-electron-transport (WET) model, to account for the physical phenomena in millimeter-wave devices. No equivalent circuit model is required to represent the innate properties of the device. Hence, the model is reliable for both small- and large-signal analyses. The electrodes of a transistor act as coupled multi-conductor transmission lines at millimeter-wave bands. The WET model consists of a device solver to obtain solutions for carrier-transport equations of the intrinsic device, and an electromagnetic solver (EM solver) to provide solutions for the …

Raman Spectroscopy Reveals Phenotype Switches In Breast Cancer Metastasis, Santosh Kumar Paidi, Joel Rodriguez Troncoso, Mason G. Harper, Zhenhui Liu, Khue G. Nguyen, Sruthi Ravindranathan, Lisa Rebello, David E. Lee, Jesse D. Ivers, David A. Zaharoff, Narasimhan Rajaram, Ishan Barman

Biomedical Engineering Faculty Publications and Presentations

The accurate analytical characterization of metastatic phenotype at primary tumor diagnosis and its evolution with time are critical for controlling metastatic progression of cancer. Here, we report a label-free optical strategy using Raman spectroscopy and machine learning to identify distinct metastatic phenotypes observed in tumors formed by isogenic murine breast cancer cell lines of progressively increasing metastatic propensities. Methods: We employed the 4T1 isogenic panel of murine breast cancer cells to grow tumors of varying metastatic potential and acquired label-free spectra using a fiber probe-based portable Raman spectroscopy system. We used MCR-ALS and random forests classifiers to identify putative spectral …

Contrastive Learning For Unsupervised Auditory Texture Models, Christina Trexler

Computer Science and Computer Engineering Undergraduate Honors Theses

Sounds with a high level of stationarity, also known as sound textures, have perceptually relevant features which can be captured by stimulus-computable models. This makes texture-like sounds, such as those made by rain, wind, and fire, an appealing test case for understanding the underlying mechanisms of auditory recognition. Previous auditory texture models typically measured statistics from auditory filter bank representations, and the statistics they used were somewhat ad-hoc, hand-engineered through a process of trial and error. Here, we investigate whether a better auditory texture representation can be obtained via contrastive learning, taking advantage of the stationarity of auditory textures to …

Automated Report Based System To Encourage A Greener Commute To Campus, Ronald Velasquez

Computer Science and Computer Engineering Undergraduate Honors Theses

This project consists of the design and implementation of a tool to encourage greener commutes to the University of Arkansas. Trends in commuting of the last few years show a decline in not so environment-friendly commute modes. Nevertheless, ensuring that this trend continues is vital to assure a significant impact. The created tool is an automated report system. The report displays information about different commute options. A Google form allows users to submit report requests, and a web app allows the sustainability office to process them in batches. This system was built in the Apps Script platform. It implements several …

Factors Influencing The Usage Of Shared E-Scooters In Chicago, Farzana Mehzabin Tuli, Suman Mitra, Mariah B. Crews

Civil Engineering Faculty Publications and Presentations

The rapid popularity growth of shared e-scooters creates the necessity of understanding the determinants of shared e-scooter usage. This paper estimates the impacts of temporal variables (weather data, weekday/weekend, and gasoline prices) and time-invariant variables (socio-demographic, built environment, and neighborhood characteristics) on the shared e-scooter demand by using four months (June 2019-October 2019) period of data from the shared e-scooter pilot program in Chicago. The study employs a random-effects negative binomial (RENB) model that effectively models shared e-scooter trip origin and destination count data with over-dispersion while capturing serial autocorrelation in the data. Results of temporal variables indicate that shared …