Engineering Commons^™

Rheology And Early-Age Structure Development In Binary And Ternary Blends Modified With Novel Graphene Types, Sahil Surehali, Collin Gustafson, Sayee Srikarah Volaity, Ranjith Divigalpitiya, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

Interest in the use of graphene to enhance the properties of cementitious materials is growing, but major impediments in implementation are the cost of graphene and changes in binder rheology attributable to these nanomaterials. This study explores the influence of novel, cost-effective, environment-friendly, and mass-producible graphene on the rheology and early-age structure development of cementitious binders. Two novel graphene types—fractal graphene (FG) and reactive graphene (RG)—are used in plain cement mixtures as well as those containing 30 % (by mass) of fly ash and/or limestone powder, at low dosages of ≤0.02 % by mass of binder. The early- and later-age …

Influence Of Temperature, Oxygen Partial Pressure, And Microstructure On The High-Temperature Oxidation Behavior Of The Sic Layer Of Triso Particles, Visharad Jalan, Adam Bratten, Meng Shi, Tyler Gerczak, Haiyan Zhao, Jonathan D. Poplawsky, Xiaoqing He, Grant Helmreich, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Tri structural isotropic (TRISO)-coated fuel particles are designed for use in high-temperature gas-cooled nuclear reactors, featuring a structural SiC layer that may be exposed to oxygen-rich environments over 1000 °C. Surrogate TRISO particles were tested in 0.2–20 kPa O2 atmospheres to observe the differences in oxidation behavior. Oxide growth mechanisms remained consistent from 1200–1600 °C for each PO2, with activation energies of 228 ± 7 kJ/mol for 20 kPa O2 and 188 ± 8 kJ/mol for 0.2 kPa O2. At 1600 °C, kinetic analysis revealed a change in oxide growth mechanisms between 0.2 and 6 kPa O2. In 0.2 kPa …

Thermally Stimulated Stiffening And Fly Ash's Alkaline Activation By Ca(Oh)2 Addition Facilitates 3d-Printing, Xiaodi Dai, Sharu Bhagavathi Kandy, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Torben Gaedt, Samanvaya Srivastava, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

3D-printing could offer substantial benefits to the construction industry including the fabrication of customized/bespoke components, eliminating formwork, and reducing material waste. Despite these advantages, control of the pumpability, extrudability, and buildability of 3D-printed concrete (3DPC) remains challenging. This study demonstrates how the use of fly ash (FA) enables enhanced thermal stiffening, and rapid alkali-activation in the presence of portlandite (Ca(OH)2, CH). In general, blends of CH and FA exhibit less structural build-up at low temperatures, but upon reaching a trigger temperature of 75 °C, these blends achieve rapid stiffening, at rates of ∼800 Pa/s. The rapid stiffening arises from the …

Impurity Behavior In Cast Copper Anodes: Implications For Electrorefining In A Circular Economy, Agustin Morales-Aragon, Daniel Sánchez-Rodas, Guillermo Ríos, Michael S. Moats

Materials Science and Engineering Faculty Research & Creative Works

The behavior of impurities in cast copper was investigated to simulate production with increased utilization of secondary sources within the framework of a circular economy. The incorporation of impurities, particularly Ni, Sn, and Sb, from recycled Cu may significantly impact the electrorefining process. In this study, commercial anodes were doped with Ni, Sn, and Sb concentrations of 2500–6500 g/t, 300–900 g/t, and 450–950 g/t, respectively. Anode concentrations of Pb and Bi were maintained at 1000 g/t and 350 g/t, respectively. As concentrations were examined at two levels, 860 or 1700 g/t, depending on the commercial anode used to create the …

Effects Of Gypsum And Limestone On Early-Age Hydration And Strength Optimization In Belite Calcium Sulfoaluminate Cement, Sai Akshay Ponduru, Bryan K. Aylas-Paredes, Taihao Han, Advaith Neithalath, Narayanan Neithalath, Gaurav Sant, Aditya Kumar

Materials Science and Engineering Faculty Research & Creative Works

Belite calcium sulfoaluminate cement (CSAB), an alternative to Portland cement, exhibits excellent strength at both early and later ages. However, due to its high belite content, the carbon reduction from this type of cement is not sufficient when compared to other alternative cements. To further enhance CSAB's sustainability, this study investigates the performance of CSAB when partially replaced by low-carbon mineral additives (i.e., limestone and gypsum). The primary objective is to identify the optimal mixture design by incorporating gypsum and limestone to formulate a sustainable binder that maintains high compressive strength. The CSAB is replaced (with both additives) by up …

Elevated Temperature Performance: Arc-Jet Testing Of Carbon Fiber Reinforced Zrb2 Bars Up To 2200 °C For Strength Retention Assessment, D. Sciti, A. Vinci, L. Zoli, P. Galizia, M. Mor, W. Fahrenholtz, S. Mungiguerra, R. Savino, A. M. Caporale, A. Airoldi

Materials Science and Engineering Faculty Research & Creative Works

For the first time, ultra-high temperature ceramic matrix composite bars were tested inside an arc-jet facility to investigate the impact of oxidation damage on strength retention. The composite bars, which were based on a ZrB2 / SiC matrix reinforced with 45 vol% carbon fibers, were produced by slurry impregnation and sintering. The first batch was tested under 3-point (pt) bending, and two additional batches were exposed to plasma of dissociated air up to a temperature of 2200 °C for 2 min or 2.2 min and then subjected to 3-pt bending. More than 75% of the initial strength was retained even …

Uav-Based Phytoforensics: Hyperspectral Image Analysis To Remotely Detect Explosives Using Maize (Zea Mays), Paul V. Manley, Stephen M. Via, Joel G. Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Remnant explosive devices are a deadly nuisance to both military personnel and civilians. Traditional mine detection and clearing is dangerous, time-consuming, and expensive. And routine production and testing of explosives can create groundwater contamination issues. Remote detection methods could be rapidly deployed in vegetated areas containing explosives as they are known to cause stress in vegetation that is detectable with hyperspectral sensors. Hyperspectral imagery was employed in a mesocosm study comparing stress from a natural source (drought) to that of plants exposed to two different concentrations of Royal Demolition Explosive (RDX; 250 mg kg−1, 500 mg kg−1). Classification was accomplished …

Effect Of Shrinkage-Mitigating Materials, Fiber Type, And Repair Thickness On Flexural Behavior Of Beams Repaired With Fiber-Reinforced Self-Consolidating Concrete, Jingjie Wei, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

While self-consolidating concrete (SCC) has emerged as a highly effective approach for the repair of concrete structures, there have been few investigations regarding the effect of the combination of different fiber and shrinkage-mitigating material types (shrinkage-reducing admixture, SRA; superabsorbent polymer, SAP; and expansive agent, EA) on the flexural behavior of repaired structures. This study aims to explore the influence of three different shrinkage-mitigating materials (1.25%–2.5 % SRA, 4%–8% EA, and 0.2%–0.4 % SAP), four fiber types (two macro synthetic fibers, MSFA and MSFB; 5D hooked steel fibers, 5D; a combination of 80 % 3D hooked steel +20 % short steel …

Research On Wireless Monitoring System For Internal Temperature Field Of Coal Gangue Mountain, Xiaofei Liu, Chunhao Liang, Jifa Qian, Xiaolin Li, Xuemei Li, Baoli Li, Guang Xu, Bin Zhou

Mining Engineering Faculty Research & Creative Works

In the long-term accumulation process, coal gangue can lead to severe consequences such as spontaneous combustion and explosions due to external factors. Additionally, the coal gangue that ignites spontaneously significantly pollutes the land and groundwater, causing serious risks to the health and safety of individuals living and working in the vicinity. Therefore, to mitigate the risk of spontaneous combustion resulting from the long-term accumulation of coal gangue, a monitoring system based on LoRa wireless communication technology is proposed to collect and monitor the internal temperature of coal gangue mountains in real time. In the laboratory, active temperature rise monitoring was …

Assessing The Impact Of Radar-Rainfall Uncertainty On Streamflow Simulation, Nicolás Velásquez, Witold F. Krajewski, Bong Chul Seo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Hydrological models and quantitative precipitation estimation (QPE) are critical elements of flood forecasting systems. Both are subject to considerable uncertainties. Quantifying their relative contribution to the forecasted streamflow and flood uncertainty has remained challenging. Past work documented in the literature focused on one of these elements separately from the other. With this in mind, we present a systematic approach to assess the impact of QPE uncertainty in streamflow forecasting. Our approach explores the operational Iowa Flood Center (IFC) hydrological model performance after altering two radar-based QPE products. We ran the Hillslope Link Model (HLM) for Iowa between 2015 and 2020, …

Potential Effects Of Statistical Complexity Measure In Improving The Fault Diagnosis Performance Under Speed Fluctuations, S. Sowmya, M. Saimurugan, N. Kannan, Immanuel A. Edinbarough

Informatics and Engineering Systems Faculty Publications

Many research studies are performed in extracting non-stationary signal properties such as instantaneous frequency (IF) and envelope to diagnose machinery faults under time-varying speed conditions. But accurate IF extraction is difficult from such complex fluctuating signals to identify the faults efficiently. Therefore, this paper proposes the Statistical Complexity Measure (SCM) as a feature that evaluates the randomness and complexity without any additional requirement, providing an outstanding result in multi-component fault detection under speed fluctuations. Primarily, the influence of SCM is proved by ranking the features with the help of the Random Forest (RF) algorithm. The fault classification of individual signal …

Flow And Heat Transfer Experimental Study For 3d-Printed Solar Receiving Tubes With Helical Fins At Internal Surface, Fouad Haddad, Naznin Nuria Afrin, Jianzhi Li, Peiwen Li, Bharath Pidaparthi, Samy Missoum, Ben Xu

Manufacturing & Industrial Engineering Faculty Publications

3D-printing technology was applied to fabricate novel solar thermal collection tubes that have internal heat transfer enhancement fins and external surfaces with high solar absorptivity and low emissivity due to the ability to use different materials in one tube. Helical fins were selected to introduce circumferential flow and thus minimize the circumferential temperature difference of the tube that receives sunlight on one side. The structures of the helical fins were previously optimized from computational fluid dynamics (CFD) analysis with the objective of low entropy production rate by looking for high heat transfer coefficient and relatively lower pressure loss. High-temperature alloy, …

Oxidation–Reduction Of Ti-6al-4v In Direct Energy Deposition Subject To Minimum Argon Consumption, Bharadwaja Ragampeta, Prashansa Ragampeta, Todd Sparks, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ti-6Al-4V is a well-known alloy for its low density and excellent corrosion resistance, making it popular in aerospace, marine, medical, and automotive applications. However, at elevated temperatures, the alloy forms oxides, leading to embrittlement. In additive manufacturing, particularly in the direct energy deposition (DED) process, which involves high temperatures, the alloy experiences oxidation. An inert gas chamber provides shielding during the process but limits the size of the manufactured components, and deposition in a vacuum chamber can alter the chemical composition of the alloy. Local shielding is a technique generally used for such applications, but it uses a high volume …

A Comprehensive Study Of Cooling Rate Effects On Diffusion, Microstructural Evolution, And Characterization Of Aluminum Alloys, Atiqur Rahman, Sriram Praneeth Isanaka, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Cooling Rate (CR) definitively influences the microstructure of metallic parts manufactured through various processes. Factors including cooling medium, surface area, thermal conductivity, and temperature control can influence both predicted and unforeseen impacts that then influence the results of mechanical properties. This comprehensive study explores the impact of CRs in diffusion, microstructural development, and the characterization of aluminum alloys and the influence of various manufacturing processes and post-process treatments, and it studies analytical models that can predict their effects. It examines a broad range of CRs encountered in diverse manufacturing methods, such as laser powder bed fusion (LPBF), directed energy deposition …

Innovative Cdr Testing And Development, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Under an award through the U.S. Department of Energy (DOE), the Energy & Environmental Research Center (EERC) seeks partners to evaluate carbon dioxide removal (CDR) technologies in an integrated test-bed facility. Such technologies may include biomass carbon removal and storage (BiCRS), direct air capture (DAC), marine CDR (mCDR), and enhanced mineralization.

Application Of Cementitious Materials And Fiber Reinforcement To Enhance Lime Stabilization For Nebraska Shale Soils, Jongwan Eun, Seunghee Kim, Chung R. Song, Laith Ibdah, Kenaz Owusu

Nebraska Department of Transportation: Research Reports

Lime stabilization is a widely used technique to improve weak subgrades; however, its effectiveness under freeze-thaw cycles remains a critical challenge. This study investigates the incorporation of cementitious materials and fiber to enhance the mechanical properties and environmental resistance of lime-stabilized soils under such conditions. Two types of soil, gray shale (plasticity index of 37.8) and clay soil (plasticity index of 19.0) from Nebraska, were used. Stabilization mixtures included lime dosages of 0%, 3%, and 6% by weight, combined with either 10% fly ash or 3% and 6% cement by weight, and 0% and 1% fiber. The experimental program comprised …

Ischemia/Reperfusion Injury Enhances Accumulation Of Perfluoropropane Droplets, C. Chen, S. Li, T. O. Matsunaga, E. Carr Everbach, F. Xie, T. R. Porter, F. S. Villanueva, X. Chen

Engineering Faculty Works

Objective: Perfluoropropane droplets (PD) are nanometer-sized particles that can be formulated from commercially available contrast agents. The preferential retention of PDs in diseased microvascular beds can be detected by ultrasound imaging techniques after acoustic activation and offers an opportunity for the detection of such processes as scar formation or inflammation. We hypothesized that in the presence of ischemia/reperfusion (I/R) injury, retention of intravenously injected PDs would be enhanced. Methods: Using an established intravital microscopy model of rat cremaster microcirculation, we determined the retention and subsequent acoustic activation behavior of PDs in exteriorized rat cremaster tissue. DiI-labeled droplets (200 µL) were …

Construction Of Electrically Heated Pavement Using Recycled Waste Rubber Tires, Islam M. Radwan, Mohamed Abdel-Raheem

Civil Engineering Faculty Publications

Accumulated snow on roads presents a dual risk of accidents and financial losses. Conventional de-icing methods, which rely on chemicals, salt, and heavy machinery, are unsustainable and detrimental to both the environment and infrastructure. Furthermore, they demand significant labor and pose hazards in densely populated areas. In response, heated pavement systems such as hydronic and electrically conductive concrete (ECON) have gained traction for mitigating snow accumulation on roads. However, the use of carbon fiber and carbon black in ECON raises costs and depletes valuable resources. This research introduces an inventive and sustainable approach to address snow accumulation on rigid pavements …

From Football To Construction: Transferring Leadership Competencies For The Era Of Construction 4.0, Payson W. Campisano

Construction Management

This study aims to explore the intersection of leadership competencies developed through football and their applicability to the construction industry, with a focus placed on the emerging leadership needs in Construction 4.0. Drawing on insights from interviews with current and former student-athletes who study or studied construction management at the California Polytechnic State University in San Luis Obispo, the research highlights the transferability of key leadership qualities from football, such as resilience, teamwork, and critical thinking, to the cognitive, interpersonal, business, and strategic domains of leadership within construction management. Building on the work of Yang, Sunindijo, and Wang (2020), who …

Predicting The High Temperature Deformation Behavior Of Haynes282 By A Dislocation-Density Based Crystal Plasticity Model, Tianju Chen, Huadong Fu, Shujing Dong, Yue Zhou, Yijia Gu, Caizhi Zhou, Ridwan Sakidja

Materials Science and Engineering Faculty Research & Creative Works

Mechanical behavior of Haynes282 is heavily dependent upon the microstructure state, calling for mesoscale model to study the relationship between the underlying microstructure and macroscopic performance. In this work, we employ crystal plasticity finite element method (CPFEM) to explore the deformation mechanisms of Hanyes282 subjected to tensile (short-term) and creep (long-term) tests. Haynes282 is a newly developed Ni-based superalloy, containing relatively low volume fraction (≤20%) of spherical γ′ precipitate phase. A dislocation-density based model is developed to describe the tensile and the creep behavior, where a dimension reduction algorithm is proposed to obtain more accurate inter-particle spacing. Furthermore, dislocation-particle interaction …

Nonlinear Self-Synchronizing Current Control For Single-Phase Ac Inverters, Shruti Pandey, Michael Mclntyre

Electrical and Computer Engineering Faculty Research & Creative Works

Grid-connected single-phase inverters require accurate phase detection for synchronization and power control. Traditionally, phase-locked loops (PLLs) are used to estimate grid parameters. This paper proposes a novel approach that determines the grid phase angle using only current feedback, eliminating the need for grid voltage measurements or cascaded control schemes. The proposed method integrates a phase angle observer with a current controller to regulate real and reactive power. Lyapunov stability analysis and hardware experiments validate the effectiveness of the approach.

Correlations Between Song Popularity And Their Audio Features Using Machine Learning, Rong Chen

Dissertations, Theses, and Capstone Projects

This project is an interactive visual project that explores the relationship between audio features and song popularity on Spotify using machine learning techniques. Through the collection of nearly half a million songs and implementation of seven different machine learning models, including Linear Regression, Random Forest, Decision Trees, and Gradient Boosting, I investigated how audio characteristics correlate with a song's popularity ranking. The project utilized MongoDB for data storage, Spotipy for API integration, and Streamlit with Plotly for visualization. This work provides insights into the practical challenges of large-scale music analysis and the relationship between technical audio characteristics and commercial success, …

Why Are Fairness Concerns So Important? Lessons From A Last-Mile Transportation System, Yiwei Chen, Hai Wang

Research Collection School Of Computing and Information Systems

The Last-Mile Problem refers to the provision of travel service for passengers from the nearest public transportation node to the final destination. The Last-Mile Transportation System (LMTS), which has recently emerged, provides on-demand last-mile transportation service for passengers. We consider an LMTS that consists of two types of passengers, regular-type passengers and special-type passengers (e.g., seniors, disabled people). The valuation of the last-mile service for special-type passengers is statistically higher than the one for regular-type passengers. Passengers incur disutility from waiting for the last-mile service. In this paper, we explore two fairness constraints on special-type passengers: (1) the fare for …

Economic Impact Of Energy Accounting Schemes For Commercial Systems On A Broiler Farm With Power Demand And Generation, Yi Liang, Michael Popp

Biological and Agricultural Engineering Faculty Publications and Presentations

The aim of this study was to assess the impact of the on-farm solar photovoltaic (PV) generation to offset grid electricity consumption on a commercial poultry farm in the US. Hourly electricity production by PV systems was estimated using the System Advisor Model (SAM) of the National Renewable Energy Lab (NREL) and compared with the estimated electric load demand of a broiler house. We analyzed the economic benefits of installing solar systems of three capacities under net energy metering and net energy billing pricing scenarios. Results suggested that a smaller PV installation of 35 kWp, while substantially short of meeting …

Membrane Filtration Of Nanoscale Biomaterials: Model System And Membrane Performance Evaluation For Aav2 Viral Vector Clarification And Recovery, Mara Leach, Kearstin Edmonds, Emily Ingram, Rebecca Dutch, Sumith R. Wickramasinghe, Malgorzata Chwatko, Dibakar Bhattacharyya

Chemical Engineering Faculty Publications and Presentations

The growing demand for viral vectors as nanoscale therapeutic agents in gene therapy necessitates efficient and scalable purification methods. This study examined the role of nanoscale biomaterials in optimizing viral vector clarification through a model system mimicking real AAV2 crude harvest material. Using lysed HEK293 cells and silica nanoparticles (20 nm) as surrogates for AAV2 crude harvest, we evaluated primary (depth filters) and secondary (membrane-based) filtration processes under different process parameters and solution conditions. These filtration systems were then assessed for their ability to recover nanoscale viral vectors while reducing DNA (without the need for endonuclease treatment), protein, and turbidity. …

Environmental-Health Convergence: A Deep Learning-Oriented Decision Support System For Catalyzing Sustainable Healthy Food Systems, Prince Agyemang, Ebenezer M. Kwofie, Jamie I. Baum, Dongyi Wang, Emmanuel A. Kwofie

Biological and Agricultural Engineering Faculty Publications and Presentations

To generate evidence to address food system challenges, we developed an adaptable framework for multimodel assessment of the convergence effect of health and environmental drivers in food systems. We achieved this goal by developing a modeling framework that facilitates testing and applying four deep-learning algorithms using a case study of the United States's food system. Among the models tested, the bidirectional and single-layer long short-term memory models outperformed the others with α_E(2.75) and α_H(3.51) when predicting environmental drivers and health drivers, respectively. All the models tested performed better at predicting environmental than health drivers. The best-performing …

Mixed Ion-Electron Conducting Lixag Alloy Anode Enabling Stable Li Plating/Stripping In Solid-State Batteries Via Enhanced Li Diffusion Kinetic, Anran Cheng, Pei Gao, Ruxing Wang, Kangli Wang, Kai Jiang

EKU Faculty and Staff Scholarship

Although showing huge potential in prospering the marketplace of all-solid-state lithium metal batteries (ASSLMBs), garnet-type solid electrolytes (Li6.5La3Zr1.5Ta0.6O12, LLZTO) are critically plagued by interface instability with Li anode and the vulnerability to Li dendrite, which are attributed to poor Li diffusion kinetic in bulk Li metal. Herein, a LixAg solid solution alloy with high Li diffusion kinetic is reported as a mixed ion- electron conductor (MIEC) alloy anode. The high Li diffusion kinetic stemming from a low eutectic point and a high mutual solubility of LixAg could reduce the Li concentration gradient in the anode, regulate Li electrochemical potential, and …

High Shear Stress Reduces Erg Causing Endothelial-Mesenchymal Transition And Pulmonary Arterial Hypertension, Tsutomu Shinohara, Jan-Renier Moonen, Yoon Hong Chun, Yannick C. Lee-Yow, Kenichi Okamura, Jason M. Szafron, Jordan Kaplan, Aiqin Cao, Lingli Wang, Weiguang Yang

Mechanical Engineering Faculty Publications

Background: Computational modeling indicated that pathological high shear stress (HSS; 100 dyn/cm2) is generated in pulmonary arteries (PAs; 100-500 µm) in congenital heart defects causing PA hypertension (PAH) and in idiopathic PAH with occlusive vascular remodeling. Endothelial-to-mesenchymal transition (EndMT) is a feature of PAH. We hypothesize that HSS induces EndMT, contributing to the initiation and progression of PAH.

Methods: We used the Ibidi perfusion system to determine whether HSS applied to human PA endothelial cells (ECs) induces EndMT when compared with physiological laminar shear stress (15 dyn/cm2). The mechanism was investigated and targeted to prevent PAH in a mouse with …

Effect Of Mg–Nb Oxides On Hydrogen Sorption Kinetics Of Ball-Milled Mgh2, Md. Wasikur Rahman, Muhammad Nurunnabi Siddiquee, Mohammad M. Hossain, M. Jasim Uddin

Mechanical Engineering Faculty Publications

Addition of Mg–Nb oxides (e.g. MgNb₂O₆, Mg₄Nb₂O₉, and Mg₃Nb₆O₁₁) ameliorates H₂ absorption/desorption kinetics of MgH₂ as demonstrated in the current article. H₂ desorption and absorption rates of the ball-milled MgH₂ are evidently temperature-dependent, which points out that the prior rate increases with increasing temperature (593–673 K) and vice versa. Among the tested samples, MgH₂ with Mg₃Nb₆O₁₁ nanoparticles showed superior performance. The Johnson–Mehl–Avrami equation was employed to construct H₂ desorption curves as well as …

Phase Of The Seabed Frequency-Domain Reflection Coefficient: Measurements And Modeling, Charles W. Holland

Electrical and Computer Engineering Faculty Publications and Presentations

The phase of the seabed frequency-domain reflection coefficient potentially contains valuable information on the geoacoustic properties in a layered/refracting seabed. However, heretofore, the phase has not been exploited. Measurements of phase are presented in an area of thick mud at the New England Mud Patch. In addition, a model is presented along with the modeling results. While this is only a first step towards understanding the potential value of exploiting the phase, it seems clear that in some instances, the phase not only contains valuable geoacoustic information, but carries a higher information content than the magnitude.