Engineering Commons^™

Progressive Hypoxia-On-A-Chip: An In Vitro Oxygen Gradient Model For Capturing The Effects Of Hypoxia On Primary Hepatocytes In Health And Disease, Young Bok Abraham Kang, Jinsu Eo, Beyza Bulutoglu, Martin L. Yarmush, O. Berk Usta

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Oxygen is vital to the function of all tissues including the liver and lack of oxygen, that is, hypoxia can result in both acute and chronic injuries to the liver in vivo and ex vivo. Furthermore, a permanent oxygen gradient is naturally present along the liver sinusoid, which plays a role in the metabolic zonation and the pathophysiology of liver diseases. Accordingly, here, we introduce an in vitro microfluidic platform capable of actively creating a series of oxygen concentrations on a single continuous microtissue, ranging from normoxia to severe hypoxia. This range approximately captures both the physiologically relevant oxygen gradient …

Moving Toward Prevention: Rural Water Maintenance And Sustained Service Delivery, Caleb Cord, Jeffrey P. Walters, Harold Lockwood, Pranav Chintalapati, Amy Javernick-Will, Karl Linden

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

This paper outlines a research plan to be conducted across the Sustainable WASH Systems (SWS) Learning consortium to learn from maintenance approaches both internal and external to the partnership. It follows a study commissioned by IRC WASH and SWS which gathered information on prominent existing approaches from key informants.

System Dynamics Modelling As A Tool For Assessing Rural Water Sustainability, Pranav Chintalapati, Jeffrey P. Walters, Amy Javernick-Will, Karl Linden

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

System dynamics modelling is a tool that has been used for decades in business management and economics applications, but little focus has been applied to the WASH sector.

Specifically, this paper discusses the use of causal loop diagrams and stock flow diagrams as methods to better understand the systemic drivers affecting sustainability of rural water service delivery.

Neutrophil Extracellular Traps In Breast Cancer And Beyond: Current Perspectives On Net Stimuli, Thrombosis And Metastasis, And Clinical Utility For Diagnosis And Treatment, Hunter T. Snoderly, Brian A. Boone, Margaret F. Bennewitz

Faculty & Staff Scholarship

Abstract

The formation of neutrophil extracellular traps (NETs), known as NETosis, was first observed as a novel immune response to bacterial infection, but has since been found to occur abnormally in a variety of other inflammatory disease states including cancer. Breast cancer is the most commonly diagnosed malignancy in women. In breast cancer, NETosis has been linked to increased disease progression, metastasis, and complications such as venous thromboembolism. NET-targeted therapies have shown success in preclinical cancer models and may prove valuable clinical targets in slowing or halting tumor progression in breast cancer patients. We will briefly outline the mechanisms by …

Bending Nanoindentation And Plasticity Noise In Fcc Single And Polycrystals, Ryder Bolin, Hakan Yavas, Hengxu Song, Kevin J. Hemker, Stefanos Papanikolaou

Faculty & Staff Scholarship

Abstract: We present a high-throughput nanoindentation study of in situ bending effects on incipient plastic deformation behavior of polycrystalline and single-crystalline pure aluminum and pure copper at ultranano depths (< 200 nm). We find that hardness displays a statistically inverse dependence on in-plane stress for indentation depths smaller than 10 nm, and the dependence disappears for larger indentation depths. In contrast, plastic noise in the nanoindentation force and displacement displays statistically robust noise features, independently of applied stresses. Our experimental results suggest the existence of a regime in Face Centered Cubic (FCC) crystals where ultranano hardness is sensitive to residual applied stresses, but plasticity pop-in noise is insensitive to it.

Drilling Performance Monitoring And Optimization: A Data-Driven Approach, Shan E Zehra Lashari, Ali Takbiri-Borujeni, Ebrahim Fathi, Ting Sun, Reza Rahmani, Mehdi Khazaeli

Faculty & Staff Scholarship

Abstract Drilling performance monitoring and optimization are crucial in increasing the overall NPV of an oil and gas project. Even after rigorous planning, drilling phase of any project can be hindered by unanticipated problems, such as bit balling. The objective of this paper is to implement artifcial intelligence technique to develop a smart model for more accurate and robust real-time drilling performance monitoring and optimization. For this purpose, the back propagation, feed forward neural network model was developed to predict rate of penetration (ROP) using diferent input parameters such as weight on bit, rotations per minute, mud fow (GPM) and …

A Review Of 2d And 3d Plasmonic Nanostructure Array Patterns: Fabrication, Light Management And Sensing Applications, Sujan Kassani, Katherine Curtin, Nianqiang Wu

Faculty & Staff Scholarship

Abstract: This review article discusses progress in surface plasmon resonance (SPR) of two-dimensional (2D) and three-dimensional (3D) chip-based nanostructure array patterns. Recent advancements in fabrication techniques for nano-arrays have endowed researchers with tools to explore a material’s plasmonic optical properties. In this review, fabrication techniques including electron-beam lithography, focused-ion lithography, dip-pen lithography, laser interference lithography, nanosphere lithography, nanoimprint lithography, and anodic aluminum oxide (AAO) template-based lithography are introduced and discussed. Nano-arrays have gained increased attention because of their optical property dependency (lightmatter interactions) on size, shape, and periodicity. In particular, nano-array architectures can be tailored to produce and tune plasmonic …

Exploration Of High Entropy Ceramics (Hecs) With Computational Thermodynamics - A Case Study With Lamno3±Δ, Yu Zhong, Hooman Sabarou, Xiaotian Yan, Mei Yang, Michael C. Gao, Xingbo Liu, Richard D. Sisson Jr.

Faculty & Staff Scholarship

The concept of the new category materials high entropy ceramics (HECs) has been proposed several years ago, which is directly borrowed from high entropy alloys (HEAs). It quickly attracts a lot of interests and displays promising properties. However, there is no clear definition of HECs differentiating it from HEAs, as it is still in its early research stage. In the current work, we are trying to use the classic perovskite LaMnO3±δ (LMO) to demonstrate the fundamental differences between HECs and HEAs. We have adopted the integrated defect chemistry and CALPHAD approach to investigate the mixing behavior and how it is …

Cancer Nanotechnology: Enhancing Tumor Cell Response To Chemotherapy For Hepatocellular Carcinoma Therapy, Sun Yongbing, Ma Wen, Yang Yuanyuan, He Mengxue, Li Aimin, Bai Lei, Yu Bin, Yu Zhiqiang

Faculty & Staff Scholarship

Abstract

Hepatocellular carcinoma (HCC) is one of the deadliest cancers due to its complexities, reoccurrence after surgical resection, metastasis and heterogeneity. In addition to sorafenib and lenvatinib for the treatment of HCC approved by FDA, various strategies including transarterial chemoembolization, radiotherapy, locoregional therapy and chemotherapy have been investigated in clinics. Recently, cancer nanotechnology has got great attention for the treatment of various cancers including HCC. Both passive and active targetings are progressing at a steady rate. Herein, we describe the lessons learned from pathogenesis of HCC and the understanding of targeted and non-targeted nanoparticles used for the delivery of small …

Correlated Blocking In Mmwave Cellular Networks: Macrodiversity, Outage, And Interference, Enass Hriba, Mathew C. Valenti

Faculty & Staff Scholarship

In this paper, we provide a comprehensive analysis of macrodiversity for millimeter wave (mmWave) cellular networks. The key issue with mmWave networks is that signals are prone to blocking by objects in the environment, which causes paths to go from line-of-sight (LOS) to non-LOS (NLOS). We identify macrodiversity as an important strategy for mitigating blocking, as with macrodiversity the user will attempt to connect with two or more base stations. Diversity is achieved because if the closest base station is blocked, then the next base station might still be unblocked. However, since it is possible for a single blockage to …

Improved Charge Injection And Transport Of Light-Emitting Diodes Based On Two-Dimensional Materials, Yuanming Zhou, Sijiong Mei, Dongwei Sun, Neng Liu, Fei Mei, Jinxia Xu, Xianan Cao

Faculty & Staff Scholarship

Light-emitting diodes (LEDs) are considered to be the most promising energy-saving technology for future lighting and display. Two-dimensional (2D) materials, a class of materials comprised of monolayer or few layers of atoms (or unit cells), have attracted much attention in recent years, due to their unique physical and chemical properties. Here, we summarize the recent advances on the applications of 2D materials for improving the performance of LEDs, including organic light emitting diodes (OLEDs), quantum dot light emitting diodes (QLEDs) and perovskite light emitting diodes (PeLEDs), using organic films, quantum dots and perovskite films as emission layers (EMLs), respectively. Two …

Improved Efficiency Of Perovskite Light-Emitting Diodes Using A Three-Step Spin-Coated Ch3nh3pbbr3 Emitter And A Pedot:Pss/Moo3-Ammonia Composite Hole Transport Layer, Yuanming Zhou, Sijong Mei, Dongwei Sun, Neng Liu, Wuxing Shi, Jiahuan Feng, Fei Mei, Jinxia Xu, Yan Jiang, Xianan Cao

Faculty & Staff Scholarship

High efficiency perovskite light-emitting diodes (PeLEDs) using PEDOT:PSS/MoO3-ammonia composite hole transport layers (HTLs) with different MoO3-ammonia ratios were prepared and characterized. For PeLEDs with one-step spin-coated CH3NH3PbBr3 emitter, an optimal MoO3-ammonia volume ratio (0.02) in PEDOT:PSS/MoO3-ammonia composite HTL presented a maximum luminance of 1082 cd/m2 and maximum current efficiency of 0.7 cd/A, which are 82% and 94% higher than those of the control device using pure PEDOT:PSS HTL respectively. It can be explained by that the optimized amount of MoO3-ammonia in the composite HTLs cannot only facilitate hole injection into CH3NH3PbBr3 through reducing the contact barrier, but also suppress the …

Dataset On Hydrophobicity Indices And Differential Scanning Calorimetry Thermograms For Poly(Hema)-Based Hydrogels, Ankita Bhat, Blake Smith, Cerasela-Zoica Dinu, Anthony Guiseppi-Elie

Faculty & Staff Scholarship

Hydrophobicity indices for poly(HEMA)-based hydrogels:HEMA, AEMA, and DMAEMA calculated from two differentmethods: 1) Partition coefficients, and 2) Kyte-Doolittle scaleare depicted.Thermograms from differential scanning calorimetry ofpoly(HEMA)-based hydrogels containing AEMA, DMAEMA, and amixture of AEMA and DMAEMA are included to represent the glasstransition temperature (Tg) values of the hydrogels.More information on the methodology to calculate the hydro-phobicity indices using the aforementioned methods and theprocedure for using a differential scanning calorimeter and anal-ysis of a thermogram is described.Details of how the changes in the feed composition ofpoly(HEMA)-based hydrogels was made is provided in theresearch article‘MOLECULAR ENGINEERING OF POLY(HEMA-co-PEGMA)-BASED HYDROGELS: ROLE OF MINOR AEMA …

A Novel Cooperative Distributed Secondary Controller For Vsi And Pq Inverters Of Ac Microgrids, F. Doost Mohammadi, H. Keshtkar, A. Dehghan Banadaki, A. Feliachi

Faculty & Staff Scholarship

This paper proposes a novel cooperative secondary control strategy for microgrids which is fully distributed. There is a two-layered coordination, which exists between inverter based DGs of both types, i.e. Voltage Source Inverter (VSI) and Current Source Inverter (CSI), also called PQ inverter. In first layer of the proposed two-layered cooperative control strategy, VSIs will take care of the primary average voltage regulation by implementing the average consensus algorithm (ACA); then in the second layer of control, the PQ inverters will improve the voltage quality of the microgrid while maintaining the average voltage of buses at the same desired level. …

Smart Proxy Modeling Of Sacroc Co2-Eor, Gholami Vida, Mohaghegh D. Shahab, Maysami Mohammad

Faculty & Staff Scholarship

Large CO2-enhanced oil recovery (EOR) projects usually contain an abundance of geological and good performance data. While this volume of data leads to robust models, it often results in difficult to manage, slow-running numerical flow models. To dramatically reduce the numerical run-times associated with the traditional simulation techniques, this work investigated the feasibility of using artificial intelligence and machine learning technologies to develop a smart proxy model of the Scurry Area Canyon Reef Operators Committee (SACROC) oilfield, located in the Permian Basin, TX, USA. Smart proxy models can be used to facilitate injection-production optimization for CO2-EOR projects. The use of …

Quaternion-Based Robust Attitude Estimation Using An Adaptive Unscented Kalman Filter, Antonio C. B. Chiella, Bruno O. S. Teixeira, Guilherme A. S. Pereira

Faculty & Staff Scholarship

This paper presents the Quaternion-based Robust Adaptive Unscented Kalman Filter (QRAUKF) for attitude estimation. The proposed methodology modifies and extends the standard UKF equations to consistently accommodate the non-Euclidean algebra of unit quaternions and to add robustness to fast and slow variations in the measurement uncertainty. To deal with slow time-varying perturbations in the sensors, an adaptive strategy based on covariance matching that tunes the measurement covariance matrix online is used. Additionally, an outlier detector algorithm is adopted to identify abrupt changes in the UKF innovation, thus rejecting fast perturbations. Adaptation and outlier detection make the proposed algorithm robust to …

Effects Of Charge Transport Materials On Blue Fluorescent Organic Light-Emitting Diodes With A Host-Dopant System, Neng Liu, Sijong Mei, Dongwei Sun, Wuxing Shi, Jiahuan Feng, Yuanming Zhou, Fei Mei, Jinxia Xu, Yan Jiang, Xianan Cao

Faculty & Staff Scholarship

High efficiency blue fluorescent organic light-emitting diodes (OLEDs), based on 1,3-bis(carbazol-9-yl)benzene (mCP) doped with 4,4’-bis(9-ethyl-3-carbazovinylene)-1,1’-biphenyl (BCzVBi), were fabricated using four different hole transport layers (HTLs) and two different electron transport layers (ETLs). Fixing the electron transport material TPBi, four hole transport materials, including 1,1-Bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), N,N’-Di(1-naphthyl)-N,N’-diphenyl-(1,1’-biphenyl)-4’-diamine(NPB), 4,4’-Bis(N-carbazolyl)-1,1,-biphenyl (CBP) and molybdenum trioxide (MoO3), were selected to be HTLs, and the blue OLED with TAPC HTL exhibited a maximum luminance of 2955 cd/m2 and current efficiency (CE) of 5.75 cd/A at 50 mA/cm2, which are 68% and 62% higher, respectively, than those of the minimum values found in the device with MoO3 …

Estimates Of Discharge Coefficient In Levee Breach Under Two Different Approach Flow Types, Seung Oh Lee, Kwang Seok Yoon, Jun Seon Lee, Seung Ho Hong

Faculty & Staff Scholarship

The amount of released water (discharge) in a levee breach is a primary input variable to establish an emergency action plan for the area next to the levee. However, although several studies have been conducted, there is still no widely applicable discharge coefficient formula; this needs to be known to estimate discharge amount through an opening caused by a levee breach. Sometimes, the discharge coefficient developed for a sharp crested side weir is used to rate the discharge, but, in case of a levee breach, the resulting geometry and flow types are similar to that over a broad crested weir. …

Vertical Stress And Deformation Characteristics Of Roadside Backfilling Body In Gob-Side Entry For Thick Coal Seams With Different Pre-Split Angles, Yuqi Ren, Guorui Feng, Pengfei Wang, Jun Guo, Yi Luo, Ruipeng Qian, Qiang Sun, Songyu Li, Yonggan Yan

Faculty & Staff Scholarship

Retained gob-side entry (RGE) is a significant improvement for fully-mechanized longwall mining. The environment of surrounding rock directly affects its stability. Roadside backfilling body (RBB), a man-made structure in RGE plays the most important role in successful application of the technology. In the field, however, the vertical deformation of RBB is large during the panel extraction, which leads to malfunction of the RGE. In order to solve the problem, roof pre-split is employed. According to geological conditions as well as the physical modeling of roof behavior and deformation of surrounding rock, the support resistance of RBB is calculated. The environment …

Turbulence Characteristics Before And After Scour Upstream Of A Scaled-Down Bridge Pier Model, Seung Oh Lee, Seung Ho Hong

Faculty & Staff Scholarship

Bridge pier scour is one of the main causes of bridge failure and a major factor that contributes to the total construction and maintenance costs of bridge. Recently, because of unexpected high water during extreme hydrologic events, the resilience and security of hydraulic infrastructure with respect to the scour protection measure along a river reach has become a more immediate topic for river engineering society. Although numerous studies have been conducted to suggest pier scour estimation formulas, understanding of turbulence characteristics which is dominant driver of sediment transport around a pier foundation is still questionable. Thus, to understand near bed …

Application Of Machine Learning And Artificial Intelligence In Proxy Modeling For Fluid Flow In Porous Media, Shohreh Amini, Shahab Mohaghegh

Faculty & Staff Scholarship

Reservoir simulation models are the major tools for studying fluid flow behavior in hydrocarbon reservoirs. These models are constructed based on geological models, which are developed by integrating data from geology, geophysics, and petro-physics. As the complexity of a reservoir simulation model increases, so does the computation time. Therefore, to perform any comprehensive study which involves thousands of simulation runs, a very long period of time is required. Several efforts have been made to develop proxy models that can be used as a substitute for complex reservoir simulation models. These proxy models aim at generating the outputs of the numerical …

Modeling Average Pressure And Volume Fraction Of A Fluidized Bed Using Data-Driven Smart Proxy, Amir Ansari, Shahab D. Mohaghegh, Mehrdad Shahnam, Jean-François Dietiker

Faculty & Staff Scholarship

Simulations can reduce the time and cost to develop and deploy advanced technologies and enable their rapid scale-up for fossil fuel-based energy systems. However, to ensure their usefulness in practice, the credibility of the simulations needs to be established with uncertainty quantification (UQ) methods. The National Energy Technology Laboratory (NETL) has been applying non-intrusive UQ methodologies to categorize and quantify uncertainties in computational fluid dynamics (CFD) simulations of gas-solid multiphase flows. To reduce the computational cost associated with gas-solid flow simulations required for UQ analysis, techniques commonly used in the area of artificial intelligence (AI) and data mining are used …

On The Unusual Amber Coloration Of Nanoporous Sol-Gel Processed Al-Doped Silica Glass: An Experimental Study, Alvin Chang, Yujuan He, Maria A. Torres Arango, Maoyu Wang, Yang Ren, Zhenxing Feng, Chih-Hung Chang, Knostantinos A. Sierros

Faculty & Staff Scholarship

Silica is the most abundant component on the earth’s surface. It plays an important role in many natural processes. Silica is also a critical material for a wide range of technical applications such as in optics and electronics. In this work, we discuss our recent experimental observation of the unusual amber coloration of aluminum doped sol-gel glass that has not been reported in the past. We characterized Al-doped sol-gel glasses, prepared at different sintering temperature, using a plethora of techniques to investigate the origin of this unusual coloration and to understand their structural and chemical properties. We used these experimental …

Biologically Inspired Design Of Context-Aware Smart Products, Ang Liu, Ivan Teo, Diandi Chen, Stephen Lu, Thorsten Wuest, Zhinan Zhang, Fei Tao

Faculty & Staff Scholarship

The rapid development of information and communication technologies (ICTs) and cyber–physical sys-tems (CPSs) has paved the way for the increasing popularity of smart products. Context-awareness isan important facet of product smartness. Unlike artifacts, various bio-systems are naturally characterizedby their extraordinary context-awareness. Biologically inspired design (BID) is one of the most commonlyemployed design strategies. However, few studies have examined the BID of context-aware smart prod-ucts to date. This paper presents a structured design framework to support the BID of context-awaresmart products. The meaning of context-awareness is defined from the perspective of product design.The framework is developed based on the theoretical foundations …

Programmed Design Of A Lithium–Sulfur Battery Cathode By Integrating Functional Units, Zhipeng Zeng, Wei Li, Qiang Wang, Xingbo Liu

Faculty & Staff Scholarship

Sulfur is considered to be one of the most promising cathode materials due to its high theoretical specific capacity and low cost. However, the insulating nature of sulfur and notorious “shuttle effect” of lithium polysulfides (LiPSs) lead to severe loss of active sulfur, poor redox kinetics, and rapid capacity fade. Herein, a hierarchical electrode design is proposed to address these issues synchronously, which integrates multiple building blocks with specialized functions into an ensemble to construct a self‐supported versatile cathode for lithium–sulfur batteries. Nickel foam acts as a robust conductive scaffold. The heteroatom‐doped host carbon with desired lithiophilicity and electronic conductivity …

Analyzing Public View Towards Vaccination Using Twitter, Mahajan Rutuja

Browse all Theses and Dissertations

Educating people about vaccination tends to target vaccine acceptance and reduction of hesitancy. Social media provides a promising platform for studying public perception regarding vaccination. In this study, we harvested tweets over a year related to vaccines from February 2018 to January 2019. We present a two-stage classifier to: (1) classify the tweets as relevant or non-relevant and (2) categorize them in terms of pro-vaccination, anti-vaccination, or neutral outlook. We found that the classifier was able to distinguish clearly between anti-vaccination and pro-vaccination tweets, but also misclassified many of these as neutral. Using Latent Dirichlet Allocation, we found that two …

Illuminator, Volume 2, Issue 5, Batten College Of Engineering & Technology, Old Dominion University

College of Engineering & Technology Newsletter

January 2019 issue of Illuminator, a monthly publication of ODU's Batten College of Engineering and Technology.

Simple Stability Criteria For Uncertain Continuous-Time Linear Systems, Mohammad Shekaramiz

Electrical and Computer Engineering Faculty Publications

This paper mainly deals with the stability problem of continuous-time linear systems having uncertainties. Instead of using the tradition types of Lyapunov functions, this paper provides a very different method to investigate the stability of such systems. Hence, it reduces the conservativeness of having structured uncertainties belonging to convex sets. Based on a famous theorem that specifies regions containing all the eigenvalues of a complex square matrix, sufficient criteria are proposed to guarantee the asymptotic stability of linear systems. The main merit of this method is in analyzing linear systems having uncertainties. Moreover, the proposed criteria can also be used …

Lecture 1: Stochastic Hydrology, Julianne Quinn

All ECSTATIC Materials

This is the first lecture of CE 5500: Stochastic Hydrology, taught by Julianne Quinn at the University of Virginia.

An Investigation Into The Predictive Capability Of Customer Spending In Modelling Mortgage Default, Donal Finn [Thesis]

Dissertations

The mortgage arrears crisis in Ireland was and is among the most severe experienced on record and although there has been a decreasing trend in the number of mortgages in default in the past four years, it still continues to cause distress to borrowers and vulnerabilities to lenders. There are indications that one of the main factors associated with mortgage default is loan affordability, of which the level of disposable income is a driver. Additionally, guidelines set out by the European Central Bank instructed financial institutions to adopt measures to further reduce and prevent loans defaulting, including the implementation and …