Engineering Commons^™

Iron Oxide Ore Mineralogy And Its Plant Flotation Circuits Nodal Analysis Simulation And Comparison, Ying Hou, Ahmed Sobhy, Samah Abdel Aziz

Mining Engineering Faculty Research & Creative Works

Mining operations usually provide ore of varying characteristics. At the Donganshan Sintering Plant, the ore is a low-grade, complex, hard-to-separate carbonate containing iron ore, and a two-step flotation circuit was previously developed to overcome the negative impact of the carbonates on the reverse flotation process. However, with the further expansion in the mining operations, it was difficult to maintain a highly efficient flotation process. Thus, the mineral liberation analyzer (MLA) was utilized to conduct an in-depth process mineralogy investigation. MLA showed that the main useful minerals in this ore are magnetite/hematite of 45% total iron, and the main gangue mineral …

Effect Of Type And Quantity Of Inherent Alkali Cations On Alkali-Silica Reaction, Pengfei Ma, Jiaoli Li, Jincheng Bai, Ying Zhuo, Lingyu Chi, Yanping Zhu, Zhenhua Shi, Hongyan Ma, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, the macroscopical expansion induced by alkali-silica reaction (ASR) and its corresponding ASR products are investigated using ordinary Portland cement (OPC) mortar specimens with a gradient of boosted alkalis. Experimental results show that the expansion increases with the concentration of inherent alkalis. Sodium-boosted samples expand approximately three times as much as potassium-boosted samples. ASR gels that are present in aggregate veins are calcium-free and amorphous; the atomic ratios of ASR gels are nearly independent of the type and quantity of alkali cations. Aggregate ASR gel exudation occurs in high (≥2.5 %) sodium cases and produces potential Na-shlykovite. Crystalline …

Implementation Of Experimental Static Recrystallization Of High Strength Steel Into Computational Simulation Of Multi-Pass Slab Hot Rolling, S. K. Dasari, S. Ganguly, A. Abutunis, K. Chandrashekhara, M. F. Buchely, S. N. Lekakh, R. J. O'Malley, T. Natarajan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Microstructural changes and softening due to static recrystallization have a critical influence on thermo-mechanical behavior of high strength steels during industrial multi-pass hot rolling. Numerical simulation using finite element analysis (FEA) can be used to accurately predict the softening behavior during the hot rolling process. Therefore, the implementation of an experimentally defined static recrystallization model into FEA is necessary to get realistic simulation prediction. in this study, the extent of softening during static recrystallization in Si and Mn alloyed high strength steel was measured using double hit tests. a Gleeble™ thermo-mechanical simulator was used to perform the double hit tests …

Comparison Of The Thermal Stability In Equal-Channel-Angular-Pressed And High-Pressure-Torsion-Processed Fe–21cr–5al Alloy, Maalavan Arivu, Andrew Hoffman, Jiaqi Duan, Jonathan Poplawsky, Xinchang Zhang, Frank Liou, Rinat Islamgaliev, Ruslan Valiev, Haiming Wen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Nanostructured steels are expected to have enhanced irradiation tolerance and improved strength. However, they suffer from poor microstructural stability at elevated temperatures. in this study, Fe–21Cr–5Al–0.026C (wt.%) Kanthal D (KD) alloy belonging to a class of (FeCrAl) alloys considered for accident-tolerant fuel cladding in light-water reactors is nanostructured using two severe plastic deformation techniques of equal-channel angular pressing (ECAP) and high-pressure torsion (HPT), and their thermal stability between 500–700 °C is studied and compared. ECAP KD is found to be thermally stable up to 500 °C, whereas HPT KD is unstable at 500 °C. Microstructural characterization reveals that ECAP KD …

Design Of Impact-Free Gaits For Planar Bipeds And Their Stabilization Using Impulsive Control, Aakash Khandelwal, Nilay Kant, Ranjan Mukherjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The problem of designing and stabilizing impact-free gaits is considered for point-foot planar bipeds. A set of geometric constraints, which eliminate impact forces at the time of leg interchange, are used to design the gaits. A family of gaits, where the stride length and walking speed can be chosen independently for each gait, is guaranteed to exist. A continuous controller is used to enforce the constraints associated with a desired gait and intermittent impulsive inputs are applied to stabilize the gait. A five-link biped example is used to illustrate the procedure for designing impact-free gaits. The effectiveness of the continuous …

Transportation Components Of The City Of Bennet Comprehensive Plan And Downtown Economic Development Plan, Kyle Mclaughlin

Community and Regional Planning Program: Theses

In partnership with the City of Bennet, the University of Nebraska, and Marvin Planning Consultants, this project assisted the creation of the City’s Comprehensive Plan and Downtown Economic Development Plan by creating a transportation focused report as a supplement to those plans. The project operates in six sections; Introduction and Overview, Evaluate the Present, Engage the Community, Recommendations, Strategies, and Policies, Implementation and Funding, and Monitoring and Evaluation. The project scope included existing conditions understanding, qualitative and quantitative transportation analysis, public engagement and stakeholder meetings, coordination with two plan creators, identifying transportation improvements, description of implementation steps, overview of available …

Sarcopenia Is Associated With Osteopenia And Impaired Quality Of Life In Children With Genetic Intrahepatic Cholestatic Liver Disease, Julia Boster, Nathan P. Goodrich, Cathie Spino, Kathleen M. Loomes, Estella M. Alonso, Binita M. Kamath, Ronald J. Sokol, Saul J. Karpen, Alexander Miethke, Benjamin L. Shneider, Jean P. Molleston, Rohit Kohli, Simon P. Horslen, Philip Rosenthal, Pamela L. Valentino, Jeffrey Teckman, Thomas N. Hangartner, Sundaram Shikha

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Background:
Sarcopenia occurs in pediatric chronic liver disease, although the prevalence and contributing factors in genetic intrahepatic cholestasis are not well-described. The objective of this study was to measure muscle mass in school-aged children with genetic intrahepatic cholestasis and assess relationships between sarcopenia, clinical variables, and outcomes.

Methods:
Estimated skeletal muscle mass (eSMM) was calculated on dual-energy x-ray absorptiometry obtained in a Childhood Liver Disease Research Network study of children with bile acid synthesis disorders(BASD) alpha-1 antitrypsin deficiency (a1ATd), chronic intrahepatic cholestasis (CIC), and Alagille syndrome (ALGS). Relationships between eSMM, liver disease, and transplant-free survival were assessed.

Results:
eSMM was …

Advancing Airport Project Delivery: A Comparison Of Design-Build And Traditional Methods In Terms Of Schedule And Cost Performance, Ramy Khalef, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Current airport infrastructure is in a state of decline, with reports scoring it at an underperforming classification of D+. To address this issue, significant improvement and advancement of the infrastructure is needed. With backing on an authoritative level, the nation can expect an increase in the number of improvement projects. Airport stakeholders have long been accustomed to delivering their projects using traditional methods, such as design-bid-build (DBB). Design-build (DB) is an alternative delivery method that has added benefits for project metrics, such as schedule and cost performance. There is a lack of research evaluating DB within the context of airport …

Kytc Department Of Aviation Aircraft Maintenance Technician (Amt) Program Optimization, Bethany Paris, P. Gayle Marks, Bryan Gibson

Kentucky Transportation Center Research Report

The aviation industry is a linchpin of Kentucky’s economy. Major firms such as UPS, Amazon, and DHL have major hubs at Louisville Muhammad Ali International Airport (SDF) and Cincinnati/Northern Kentucky International Airport (CVG). As of December 2022, 4,570 aircraft mechanics and service technicians (AMTs) were employed in the state. Demand in this sector is poised to grow. As such, it is critical to understand what resources Kentucky has available to train the next generation of professionals and the number of people the aviation industry is likely to employ statewide over the next decade. Kentucky and the surrounding states are home …

Motif-Cluster: A Spatial Clustering Package For Repetitive Motif Binding Patterns, Mengyuan Zhou

School of Computing: Dissertations, Theses, and Student Research

Previous efforts in using genome-wide analysis of transcription factor binding sites (TFBSs) have overlooked the importance of ranking potential significant regulatory regions, especially those with repetitive binding within a local region. Identifying these homogenous binding sites is critical because they have the potential to amplify the binding affinity and regulation activity of transcription factors, impacting gene expression and cellular functions. To address this issue, we developed an open-source tool Motif-Cluster that prioritizes and visualizes transcription factor regulatory regions by incorporating the idea of local motif clusters. Motif-Cluster can rank the significant transcription factor regulatory regions without the need for experimental …

Flying To Net Zero With Sustainable Atos; Changing Cultures​, Eva Maleviti

Publications

What is Sustainability?

• World Commission on Environment and Development’s (WCED) 1987 Brundtland Report ‘’Our Common Future’’.
• Help world nations towards sustainable development.

17 Sustainable Development Goals

• The start of all industries are the 17 SDGs
• Aviation can address the 15 SDGs
• Net zero target suggest reduction of aviation emissions up to 21.2 Gt CO2

Design And Scale Model Of Wave Generator For The Testing Of Wave Energy Conversion Devices, Amanda Olla

Master's Theses

As the climate crisis draws more concern, research and development in wave energy as a renewable energy source has increased. Devices such as wave energy converters (WECs) are being researched, tested, and implemented to make wave energy a competitive power source. Testing of these devices is limited due to environmental concerns such as weather, location, and other issues. WECs require testing in a marine environment, however, performing testing in the actual environment may be difficult due to weather, access, mounting, and other issues. To eliminate environmental unknowns from testing, a wave simulator device can mimic wave behavior without the need …

Novel Castor Oil/Water/Ethanol Pickering Emulsions Stabilized By Magnetic Nanoparticles And Magnetically Controllable Demulsification, Mohammad J. Hasan, Peng Chen, Neithan Dominick, Erick S. Vasquez, Esteban E. Ureña-Benavides

Chemical and Materials Engineering Faculty Publications

A novel castor oil/water/ethanol Pickering emulsion, stabilized by magnetic nanoparticles (NPs), was developed to allow on-demand demulsification by an external magnetic field for the extraction of ethanol from aqueous solution using the castor oil. The emulsion was stabilized by Fe3O4-coated cellulose nanocrystals (CNC@Fe3O4) and lignin-coated Fe3O4 NPs (lignin@Fe3O4). The stability of the emulsions was investigated at various castor oil to ethanol-water ratios (50/50 and 70/30), various NP concentrations, and ethanol concentrations in the aqueous phase. The magnetically controlled demulsification ability of the emulsions was investigated by using a permanent magnet. The results showed that the 70/30 emulsions were more stable …

Urban Versus Lake Impacts On Heat Stress And Its Disparities In A Shoreline City, T. C. Chakraborty, Jiali Wang, Yun Qian, William Pringle, Zhao Yang, Pengfei Xue

Michigan Tech Publications

Shoreline cities are influenced by both urban-scale processes and land-water interactions, with consequences on heat exposure and its disparities. Heat exposure studies over these cities have focused on air and skin temperature, even though moisture advection from water bodies can also modulate heat stress. Here, using an ensemble of model simulations covering Chicago, we find that Lake Michigan strongly reduces heat exposure (2.75°C reduction in maximum average air temperature in Chicago) and heat stress (maximum average wet bulb globe temperature reduced by 0.86°C) during the day, while urbanization enhances them at night (2.75 and 1.57°C increases in minimum average air …

Deficient Aeronautical Decision-Making Contributions To Fatal General Aviation Accidents, Douglas D. Boyd, Mark Scharf Phd

Publications

INTRODUCTION: General aviation (GA), mainly comprised of light (≤12,500 lb) aircraft, maintains an inferior safety record compared with air carriers. To improve safety, aeronautical decision-making (ADM) practices have been advocated to GA pilots since 1991. Herein, we determined the extent to which GA pilots disregard such practices. METHODS: Fatal accidents (1991–2019) involving private pilots (PPLs) in single-engine airplanes were identified (N = 1481) from the National Transportation Safety Board AccessR database. Of these, deficient go/no-go and in-flight ADM-related mishaps were scored using the PAVE (pilot, aircraft, environment, external pressure)/IMSAFE (illness, medicine, stress, alcohol, fatigue, eating) and PPP (perceive, process, …

Design Guidance For Wetland-Road Crossings To Reduce Blanding’S Turtle Mortality Risk, Thomas P. Ballestero, Lauren E. White, Sandra Houghton, David Burdick, Josh Megyesy

Faculty Publications

Road mortality is a leading threat to freshwater turtles, particularly the Blanding’s turtle (Emydoidea blandingii), an endangered species in New Hampshire. Wildlife wetland-crossing structures, such as culverts and/or fences, have proven effective in reducing wildlife road mortality while retaining habitat connectivity. Funding for adequate wetland-crossing creation or restoration is limited, so prioritizing areas of high mortality risk is essential to ensuring that the resources spent are impactful. A research team of professionals from the New Hampshire Department of Environmental Services, New Hampshire Fish and Game, University of New Hampshire, and other organizations formed to create a model capable …

An Amplification-Free Crispr-Sers Biosensor For Specific, Sensitive And Rapid Detection Of Salmonella Typhimurium In Poultry, Fei Jia, Bingyan Li, Yawen He, Yafang Shen, Juhong Chen, Xingmin Li, Yanbin Li

Biological and Agricultural Engineering Faculty Publications and Presentations

CRISPR (Clustered regularly interspaced short palindromic repeats) has been a cutting-edge biotechnology in both gene editing and biosensing due to its desirable features, such as high base resolution and set-and-forget operation. However, as a nucleic acid detection method, an DNA/RNA amplification procedure is still inevitable in CRISPR biosensors. In this study, a highly-ordered nanopore array SERS substrate, coated with silver nanoparticles, was fabricated and utilized as a platform for the specific detection of Salmonella Typhimurium (S. Typhimurium) without the time-consuming DNA amplification step. The smart sensing strategy was established by introducing an ssDNA labeled with a Raman active molecule …

Integrating The Concept Of Complete Streets Into Pavement Preservation, Sirisha Gangireddy

LSU Master's Theses

This study is motivated by the evident gap in integrating Complete Streets principles into pavement preservation. Complete Streets opportunities, which aim to accommodate all road users, are typically encouraged in all kinds of projects including new construction, reconstruction, preservation, and rehabilitation. While the concept of Complete Streets is understood in terms of new construction (e.g., building sidewalks), its application through pavement preservation programs is not well-developed. To bridge the gap between the Complete Streets and pavement preservation, this study conducted a comprehensive review on how state Department of Transportation (DOTs) are currently incorporating Complete Streets into pavement preservation and identified …

Digital Twins Of The Living Knee: From Measurements To Model, Thor Erik Andreassen

Electronic Theses and Dissertations

Modern medicine has dramatically improved the lives of many. In orthopaedics, robotic surgery has given clinicians superior accuracy when performing interventions over conventional methods. Nevertheless, while these and many other methods are available to ensure treatments are performed successfully, far fewer methods exist to predict the proper treatment option for a given person. Clinicians are forced to categorize individuals, choosing the best treatment on “average.” However, many individuals differ significantly from the “average” person, for which many of these treatments are designed. Going forward, a method of testing, evaluating, and predicting different treatment options' short- and long-term effects on an …

Building Services Engineering November/December 2023

Building Services Engineering

No abstract provided.

Growth Of Germanium Thin Films On Sapphire Using Molecular Beam Epitaxy, Emmanuel Wangila, Peter Lytvyn, Hryhorii Stanchu, Calbi Gunder, Fernando Maia De Oliveira, Samir Saha, Subhashis Das, Niroshi Eldose, Chen Li, Mohammad Zamani-Alavijeh, Mourad Benamara, Yuriy I. Mazur, Shui-Qing Yu, Gregory J. Salamo

Electrical Engineering Faculty Publications and Presentations

Germanium films were grown on c-plane sapphire with a 10 nm AlAs buffer layer using molecular beam epitaxy. The effects of Ge film thickness on the surface morphology and crystal structure were investigated using ex situ characterization techniques. The nucleation of Ge proceeds by forming (111) oriented three-dimensional islands with two rotational twin domains about the growth axis. The boundaries between the twin grains are the origin of the 0.2% strain and tilt grains. The transition to a single-grain orientation reduces the strain and results in a better-quality Ge buffer. Understanding the role of thickness on material quality during the …

Biomimetic Approach To Elucidate The Role Of Microenvironment In Regulating Cell Communications In Liver Diseases, Youra Moeun

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Liver is a complex organ but often underappreciated for its functions to remove toxins and fight infection in the body. Despite the ongoing prevalence of patients contracting chronic liver diseases, coupled with a global healthcare investment of approximately $70 billion, there is still no effective treatment for chronic liver diseases including alcoholic liver disease. The purpose of this dissertation was to understand the interactions of parenchymal and non-parenchymal liver cells in physiological and pathological like environments. This allowed us to recreate a healthy and the diseased microenvironments to observe the stages of the liver diseases development and apply appropriate treatments …

Modeling Overdraft-Driven Nitrate Transport In Shallow Wells For Mitigation And Scenario Planning, Jonathan Cronk

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

In Nebraska, average nitrate concentrations in groundwater have doubled since 1974, making water quality management more important than ever. As droughts, heat waves, and floods become more common climate events, understanding their impacts will be necessary to make informed management decisions. Emerging literature describes that drought correlates to an increase in the concentration of nitrate-N at domestic and irrigation wells, however the relative contributions of the mechanisms thought to be responsible is currently unknown.

This research assessed the impact of recharge and pumping rate changes as two mechanisms affecting nitrate-N concentration during drought, assessed the relationship between well depth and …

Meta-Analysis Of Insulated Concrete Wall Panel Design Methods For Shear And Flexure Behavior, Maryam Al-Bayati

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Insulated Concrete wall panels have been designed and constructed since the early 1950s with various shear ties, dimensions, and methods; nonetheless, thermal bridging and rational design are still a concern. Many companies have recently developed plastic connectors that have gradually replaced solid concrete sections and steel connectors due to their superior thermal efficiency and strength. However, there is no generally accepted method for predicting the behavior of sandwich wall panels in structural engineering practice or codes, but many methods have been used since the early 1920. This study aims to evaluate the accuracy of current methods for predicting the flexural …

Continuous Time Recurrent Network For Human Activity Detection, Abdallah Al Zubi

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Human activity detection is crucial to personalize the control of the building environment. For example, understanding certain human activities (e.g., walking, sitting, etc.) for an occupant in a building helps provide the proper thermal comfort control. However, these applications require large-scale neural networks that are challenging to implement and train.

In this thesis, we implemented a continuous-time recurrent neural network implementation (CTRNN) network that can solve real-time human activity detection with a smaller-size network. The CTRNN uses differential equations with a time constant to describe the neuron equations. It was implemented and trained for the first time using TensorFlow. Specifically, …

Skip The Grid: Solar System Installations In The Navajo Nation, Gina H. Chun

Construction Management

Skip the Grid is an interdisciplinary project that involves installing solar energy systems in the Navajo Nation. The project’s mission was to support the Navajo families, specifically the students that have limited access to light which directly affects their education. On March 26, 2023, a team of 20 California Polytechnic State University San Luis Obispo (Cal Poly) students, across eight different majors, travelled to Arizona to collaborate with the Red Mesa and Chinle Unified School Districts to install “off-grid” solar energy systems and lights. Through this project the Cal Poly students learned about the people of Navajo Nation, solar energy, …

Vacancy Ordering In Zirconium Carbide With Different Carbon Contents, Yue Zhou, Jeremy Lee Watts, Cheng Li, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

Zirconium carbide (ZrCx) ceramics with different carbon contents were prepared by reactive hot-pressing. The rock-salt structure of ZrCx was the only phase detected by x-ray diffraction of the hot pressed ceramics. The relative densities of ZrCx decreased as carbon content increased, in general. The actual carbon contents were measured by completely oxidizing the ZrCx ceramics to ZrO₂. For most compositions, the actual carbon contents were higher than nominal batched compositions, presumably due to carbon uptake from the graphite furnace and hot press dies. Selected area electron diffraction and neutron powder diffraction revealed the presence of carbon vacancy ordering …

Searching For Unknown Material Properties For Am Simulations, Aaron Flood, Rachel Boillat, Sriram Praneeth Isanaka, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Additive manufacturing (AM) simulations are effective for materials that are well characterized and published; however, for newer or proprietary materials, they cannot provide accurate results due to the lack of knowledge of the material properties. This work demonstrates the process of the application of mathematical search algorithms to develop an optimized material dataset which results in accurate simulations for the laser directed energy deposition (DED) process. This was performed by first using a well-characterized material, Ti-64, to show the error in the predicted melt pool was accurate, and the error was found to be less than two resolution steps. Then, …

Building Services Engineering September/October 2023

Building Services Engineering

No abstract provided.

Heat Transfer Performance Of Single-Phase Circular Heat Sink With Micro Pin-Fin, Mouza Abdulla Al Shamsi

Theses

This thesis presents a numerical study of laminar forced convection in a novel design of a microscale single phase water cooled circular heat sink with pin fins developed and analyzed to serve as a miniaturized cooling system. The developed heat sink in this study aims to achieve efficient heat dissipation from high electronics integration that generates high heat flux and non-uniform temperature distribution, which leads to the reduction of life and reliability of electronic devices.

Numerical analysis of ten different configurations of the circular heat sink has been carried out for the heat flux of 100 W/cm2 at range of …