Engineering Commons^™

Multipolymer Microsphere Delivery Of Sars-Cov-2 Antigens, Farah Shahjin, Milankumar Patel, Jatin Machhi, Jacob D. Cohen, Mohammad Ullah Nayan, Pravin Yeapuri, Chen Zhang, Emiko Waight, Mahmudul Hasan, Mai Mohamed Abdelmoaty, Prasanta K. Dash, You Zhou, Irene Andreu, Howard E. Gendelman, Bhavesh D. Kevadiya

Nebraska Center for Biotechnology: Faculty and Staff Publications

Effective antigen delivery facilitates antiviral vaccine success defined by effective immune protective re- sponses against viral exposures. To improve severe acute respiratory syndrome coronavirus-2 (SARS-CoV- 2) antigen delivery, a controlled biodegradable, stable, biocompatible, and nontoxic polymeric micro- sphere system was developed for chemically inactivated viral proteins. SARS-CoV-2 proteins encapsulated in polymeric microspheres induced robust antiviral immunity. The viral antigen-loaded microsphere sys- tem can preclude the need for repeat administrations, highlighting its potential as an effective vaccine.

Phase-Averaged, Frequency Dependence Of Jet Dynamics In A Scaled Up Vocal Fold Model With Full And Incomplete Closure, Nathaniel Wei, Abigail Haworth, Hunter Ringenberg, Michael Krane, Timothy Wei

Department of Mechanical and Materials Engineering: Faculty Publications

This study focuses on frequency dependence effects on glottal jet dynamics with a focus on the physiological condition in which the vocal folds do not fully close. Incomplete closure occurs naturally in children and adult females. But there are also pathological conditions that can be problematic. Experiments were conducted using a 10× scaled-up model in a free surface water tunnel. Two-dimensional vocal fold models with semicircular medial surfaces were stepper motor driven inside a square duct with constant opening and closing speeds. Cases with complete vocal fold closure and incomplete closure to only 15% of the maximum gap were examined. …

Sars-Cov-2 Detecting Rapid Metasurface-Based Sensor, Shobhit K. Patel, Jaymit Surve, Juveriya Parmar, Khaled Aliqab, Meshari Alsharari, Ammar Armghan

Department of Mechanical and Materials Engineering: Faculty Publications

We have proposed a novel approach to detect COVID-19 by detecting the ethyl butanoate which high volume ratio is present in the exhaled breath of a COVID-19 infected person. We have employed a refractive index sensor (RIS) with the help of a metasurface-based slotted T-shape perfect absorber that can detect ethyl butanoate present in exhaled breath of COVID-19 infected person with high sensitivity and in-process SARS-CoV-2. The optimized structure of the sensor is obtained by varying several structure parameters including structure length and thickness, slotted T-shape resonator length, width, and thickness. Sensor’s performance is evaluated based on numerous factors comprising …

The Combined Impact Of Redcedar Encroachment And Climate Change On Water Resources In The Nebraska Sand Hills, Yaser Kishawi, Aaron R. Mittelstet, Zablon Adane, Nawaraj Shrestha, Paolo Nasta

Biological Systems Engineering: Papers and Publications

The Nebraska Sand Hills (NSH) is considered a major recharge zone for the High Plains Aquifer in the central United States. The uncontrolled expansion of the eastern redcedar (Juniperus Virginiana) under climate warming is posing threats to surface water and groundwater resources. The combined impact of land use and climate change on the water balance in the Upper Middle Loup River watershed (4,954 km²) in the NSH was evaluated by simulating different combination of model scenarios using the Soil Water Assessment Tool (SWAT) model. A total of 222 climate models were ranked according to the aridity …

Applying Unsupervised Machine Learning Clustering Techniques To Early Childcare Soundscapes, Kenton Hummel, Erica E. Ryherd, Iason Konstantzos, Abbie Raikes

Durham School of Architectural Engineering and Construction: Faculty Publications

Early childhood is a critical time period for language, brain, cognitive, and social/emotional development. Out-of-home childcare is a normative, typical experience for millions of young children. Although Indoor Environmental Quality (IEQ) in K-12 settings has received recent, significant attention, the links between IEQ and children’s learning and development in early childcare settings is a less understood topic. This work focuses specifically on the sound aspect of IEQ in early childcare settings to better understand typical noise levels and occupant experience. Standard approaches to analyzing background noise will be presented alongside more detailed statistical analyses utilizing unsupervised machine learning clustering techniques. …

Estimation Of Cotton Canopy Parameters Based On Unmanned Aerial Vehicle (Uav) Oblique Photography, Jinyong Wu, Sheng Wen, Yubin Lan, Xuanchun Yin, Jiantao Zhang, Yufeng Ge

Biological Systems Engineering: Papers and Publications

Background: The technology of cotton defoliation is essential for mechanical cotton harvesting. Agricultural unmanned aerial vehicle (UAV) spraying has the advantages of low cost, high efficiency and no mechanical damage to cotton and has been favored and widely used by cotton planters in China. However, there are also some problems of low cotton defoliation rates and high impurity rates caused by unclear spraying amounts of cotton defoliants. The chemical rate recommendation and application should be based upon crop canopy volume rather than on land area. Plant height and leaf area index (LAI) is directly connected to plant canopy structure. …

Comparative Study Of Differentiating Human Pluripotent Stem Cells Into Vascular Smooth Muscle Cells In Hydrogel-Based Culture Methods, Qing Liu, Zhen Liu, Hongyu Gu, Yuxia Ge, Xuesheng Wu, Fuxing Zuo, Qian Du, Yuguo Lei, Zhanqi Wang, Haishuang Lin

Biological Systems Engineering: Papers and Publications

Vascular smooth muscle cells (VSMCs), which provides structural integrity and regulates the diameter of vasculature, are of great potential for modeling vascular-associated diseases and tissue engineering. Here, we presented a detailed comparison of differentiating human pluripotent stem cells (hPSCs) into VSMCs (hPSCs-VSMCs) in four different culture methods, including 2-dimensional (2D) culture, 3-dimensional (3D) PNIPAAm-PEG hydrogel culture, 3-dimensional (3D) alginate hydrogel culture, and transferring 3- dimensional alginate hydrogel culture to 2-dimensional (2D) culture. Both hydrogel-based culture methods could mimic in vivo microenvironment to protect cells from shear force, and avoid cells agglomeration, resulting in the extremely high culture efficiency (e.g., high …

Nanoscale Imaging Of Antiferromagnetic Domains In Epitaxial Films Of Cr2O3 Via Scanning Diamond Magnetic Probe Microscopy, Adam Erickson, Syed Qamar Abbas Shah, Ather Mahmood, Ilja Fescenko, Christian H. Binek, Adbelghani Laraoui

Department of Mechanical and Materials Engineering: Faculty Publications

We report direct imaging of boundary magnetization associated with antiferromagnetic domains in magnetoelectric epitaxial Cr₂O₃ thin films using diamond nitrogen vacancy microscopy. We found a correlation between magnetic domain size and structural grain size which we associate with the domain formation process. We performed field cooling, i.e., cooling from above to below the Néel temperature in the presence of a magnetic field, which resulted in the selection of one of the two otherwise degenerate 180° domains. Lifting of such a degeneracy is achievable with a magnetic field alone due to the Zeeman energy of a weak …

Behavior Of Completely Automated Evapotranspiration Estimation (Eemetric), Atiqullah Atif

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Evapotranspiration (ET) is the second-largest component in the water balance equation, globally consuming 70% of the earth’s annual precipitation. Accurate and consistent estimation of ET is essential for ensuring water resources sustainability, proper management, planning, and regulations of water resources. Though a 100% accurate estimation of ET may not be feasible with the current technology, there are proven techniques that give us estimates of ET we can heavily rely on. Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) is a widely used surface energy balance model that produces relatively accurate ET maps utilizing remote sensing data and requires skilled …

Semantic Segmentation Based Deep Learning Approaches For Weed Detection, Puranjit Singh

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

Global increase in herbicide use to control weeds has led to issues such as evolution of herbicide-resistant weeds, off-target herbicide movement, etc. Precision agriculture advocates Site Specific Weed Management (SSWM) application to achieve precise and right amount of herbicide spray and reduce off-target herbicide movement. Recent advancements in Deep Learning (DL) have opened possibilities for adaptive and accurate weed recognitions for field based SSWM applications with traditional and emerging spraying equipment; however, challenges exist in identifying the DL model structure and train the model appropriately for accurate and rapid model applications over varying crop/weed growth stages and environment. In our …

Interlayered Thin Film Composite (Itfc) Membranes: The Synthesis And Assembly Of Active Layer From Conjugated Microporous Polymer, Febby Andini

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The pursuit of advanced materials with well-defined structures at sub-1 nm size, multi-functionalities, and superior chemical stability is essential for enhanced separation performance but technically challenging. Limitations of conventional TFC membranes for use in Organic Solvent Nanofiltration (OSN) can be addressed by manipulating the pore size and chemical properties of the film with novel materials. Conjugated microporous polymers (CMPs) are promising in a few years because of their highly ordered structure and excellent stability. Porphyrin, one of the basic building blocks, can form a conjugated polymer. Herein, poly(5,10,15,20-tetrakis(4-aminophenyl)porphyrin) or PTAPP, is considerably selected as an active layer from CMPs using …

An Empirical Study On The Classification Of Python Language Features Using Eye-Tracking, Jigyasa Chauhan

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Python, currently one of the most popular programming languages, is an object-
oriented language that also provides language feature support for other programming
paradigms, such as functional and procedural. It is not currently understood how
support for multiple paradigms affects the ability of developers to comprehend that
code. Understanding the predominant paradigm in code, and how developers classify
the predominant paradigm, can benefit future research in program comprehension as
the paradigm may factor into how people comprehend that code. Other researchers
may want to look at how the paradigms in the code interact with various code smells.
To investigate how …

A Robust Platform For Mobile Robotics Teaching And Developing Using Arduino’S Integrated Development Environment (Ide) For Programming The Arduino Mega 2560, Sajjad Alhassan

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In light of the rapid pace at which development happens with modern technology, mobile robots play an important role in our daily lives. This is due to their great importance in facilitating the affairs of life in various economic, commercial, industrial, scientific, and many other fields. In this research and project, we have restructured the microcontroller and system for one of the mobile robots (CEENBOT) that was designed by the University of Nebraska and replaced it with an Arduino Mega 2560.

The purpose of using the Arduino Mega 2560 robot is to provide alternative programming for the CEENBOT platform to …

Experimental And Numerical Study: Sheet Pile Abutment Systems For Water–Crossing Bridges, Hung Phi Van

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Sheet piles are geotechnical-structural elements with interlocking edges together that are driven into the ground to deliver soil retention and excavation support. Steel sheet pile walls are widely used for retaining walls, riverbank protection, seawalls, cofferdams, etc. In Nebraska, sheet pile walls prevent scouring and protect backfill for bridge abutment systems. While sheet piling is not designed and applied to resist vertical load, several recent studies attempted to investigate whether sheet piles could be employed for axial load bearing. Many projects from Europe and some in the U.S. have utilized the axial load-bearing capacity of sheet piles in bridge abutment …

Interdisciplinary Design Studio: Programming Document Visioning For A Robotic Demonstration, Research, And Engagement Dairy, Steve(N) Hardy, Nate Bicak, Sarah Alduaylij, Noor Al-Maamari, Devyn Beekman, Kelsey Belgum, Lauren Chubb, Nicholas Forte, Mitchell Hill, Joshua Holstein, Dylan Lambe, Phuong Le, Mia Leriger, Elizabeth Loftus, Josh Lorenzen, Megan Lovci, Alex Martino, Zade Miller, Hannah Morgan, Annabelle Nichols, Collin Shearman, Rebecca Sowl, Nalin Theplikhith, Angela Vu, Shaylee Wagner, Ethan Watermeier, Trever Zelenka

Student Creative Activity, Architecture Program

The 2022 COLLABORATE Design Studio brought together students from various disciplines to address a complex, real-world project which required collaborative input from different perspectives. The studio worked to advance the co-creation of knowledge between external stakeholders, students, and instructors. The course was co-taught by faculty from different disciplines, and areas of expertise. During the semester, Nate Bicak and Steven Hardy worked with students from Architecture and Interior Design in collaboration with students in Dr. Tami Brown-Brandl’s students in Biological Systems Engineering and Animal Science to explore the values, spatial qualities, and area requirements of a Robotic Demonstration, Research, and Engagement …

Earlier Snowmelt May Lead To Late Season Declines In Plant Productivity And Carbon Sequestration In Arctic Tundra Ecosystems, Donatella Zona, Peter M. Lafleur, Koen Hufkens, Barbara Bailey, Beniamino Gioli, George Burba, Jordan P. Goodrich, Anna K. Liljedahl, Eugénie S. Euskirchen, Jennifer D. Watts, Mary Farina, John S. Kimball, Martin Heimann, Mathias Göckede, Martijn Pallandt, Torben R. Christensen, Mikhail Mastepanov, Efrén López-Blanco, Marcin Jackowicz-Korczynski, Albertus J. Dolman, Luca Belelli Marchesini, Roisin Commane, Steven C. Wofsy, Charles E. Miller, David A. Lipson, Josh Hashemi, Kyle A. Arndt, Lars Kutzbach, David Holl, Julia Boike, Christian Wille, Torsten Sachs, Aram Kalhori, Xia Song

Daugherty Water for Food Global Institute: Faculty Publications

Arctic warming is affecting snow cover and soil hydrology, with consequences for carbon sequestration in tundra ecosystems. The scarcity of observations in the Arctic has limited our understanding of the impact of covarying environmental drivers on the carbon balance of tundra ecosystems. In this study, we address some of these uncertainties through a novel record of 119 site-years of summer data from eddy covariance towers representing dominant tundra vegetation types located on continuous permafrost in the Arctic. Here we found that earlier snowmelt was associated with more tundra net CO2 sequestration and higher gross primary productivity (GPP) only in June …

High Throughput And Highly Controllable Methods For In Vitro Intracellular Delivery, Justin Brooks, Grayson Minnick, Prithvijit Mukherjee, Arian Jaberi, Lingqian Chang, Horacio D. Espinosa, Ruiguo Yang

Department of Mechanical and Materials Engineering: Faculty Publications

In vitro and ex vivo intracellular delivery methods hold the key for releasing the full potential of tissue engineering, drug development, and many other applications. In recent years, there has been significant progress in the design and implementation of intracellular delivery systems capable of delivery at the same scale as viral transfection and bulk electroporation but offering fewer adverse outcomes. This review strives to examine a variety of methods for in vitro and ex vivo intracellular delivery such as flow-through microfluidics, engineered substrates, and automated probe-based systems from the perspective of throughput and control. Special attention is paid to a …

Mango Surface Color Features Measurement Using Digital Image Processing, Md Towfiqur Rahman, Goutom Kumar, Md Abdul Momin

Biological Systems Engineering: Papers and Publications

Summary

Postharvest processing of agricultural produce is still done the conventional way in Bangladesh. Manual grading of agricultural produce, especially fruits and vegetables, is laborious and costly due to acute shortage of labor during the peak season, as well as difficulty maintaining the product quality. Machine vision system (MVS) applications are widely used nowadays as a non-destructive and cost-effective technology for automatically grading and sorting large volumes of produce in the packing house according to size, shape, color, texture, and surface defects. In this study, a simple MVS was constructed measuring different color features of mango fruit surface as a …

Immobilized Algae For Produced Water Treatment And Desalination, Shibin Nadersha, Ashraf Aly Hassan

Department of Civil and Environmental Engineering: Faculty Publications

Produced water (PW) is the effluent generated during oil mining and extraction. On average, for every barrel of oil, 4-5 barrels of PW are generated worldwide. The presence of various contaminants in PW makes it toxic. Disposal of untreated PW into oceans and water bodies can cause adverse effects on human health and the environment. Taking into account the large volumes of it being generated, and its effects on the environment, proper treatment is required before reuse or disposal. Microalgal treatment is an effective method for the bioremediation and biodesalination of produced water when acclimatized algal biomass is used for …

Evaluation Of Swelling Pressure And Shear Strength Of Inorganic Microfiber-Reinforced Bentonite For The Engineered Barrier System, Jose Maria Ferdinand Victoria Calaunan

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Nowadays, the permanent disposal of high-level radioactive waste materials has been a primary concern in several countries. The deep geological repository, being the preferred disposal method across the globe, utilizes a network of engineered barriers to prevent the radioactive material from spreading throughout the facility and harming the natural environment. Part of this engineered barrier system (EBS) is the buffer material, which essential function is holding the radioactive waste-containing canister in place. However, the potential generation of desiccation cracks in this buffer material is imminent due to the heat emitted from the radioactive waste. Knowing the capability of inorganic fibers …

Empirical Fragility Functions And Numerical Parametric Study For Buckling Of Steel Grain Bins Under High Wind Loads, Andrew Ruder

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

While rural infrastructure is critical to the agricultural industry, it has been historically more susceptible to damage and slower to recover following natural disasters than its urban and suburban counterparts. This has been made evident most recently by the events of the August 10, 2020, derecho in which rural regions in Iowa were among the hardest hit areas with sustained windspeeds exceeding 120 mph. Among the most frequently damaged structures in this event were corrugated steel grain bins, which farmers and co-ops use to dry and store certain commodities. Unlike most other critical structures, steel grain bins are not designed …

Measuring Acoustic Nonlinearity Of Elastic Materials Using Thermal Modulation Of Ultrasonic Waves, Bibo Zhong

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Nonlinear acoustic techniques have been used to determine the nonlinear properties of materials. Existing methods either require complex equipment to measure absolute nonlinear coefficients or can only be used on laboratory-sized specimens. A recently developed thermal modulation method addresses the limitations of existing methods, but further theoretical analysis and validation are required.

In this dissertation, theoretical analyses were first conducted to study the mechanically and thermally induced acoustoelastic effect. Beginning with the wave equation, the relationship of the ultrasonic wave velocity with respect to mechanical strain and the thermal strain was derived in detail. These analyses provided theoretical support for …

Parametric Modeling Of Biomimetic Sharkskin For Wire Edm For Drag Reduction And Hydrophobicity, Joel Maxwell

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This research sets out to demonstrate the viability of parametric modeling for biomimetic sharkskin in the effort to reduce drag and create a self-cleaning surface. Multiple designs were created to be machined by Wire EDM on stainless steel and titanium and were comparatively tested. Limitations of current manufacturing processes to economically produce naturally occurring structures such as sharkskin, emphasize the need to be able to calculate the most accurate design for a given manufacturing process. By designing a simplified but parametrically consistent model compared to an accurately depicted 3D model of sharkskin, the textured samples produced can be further tested …

Multi-Criteria Decision Matrix Method In The Risk Analysis Of Biodiesel Production Processes, Kaylee Alles

Department of Chemical and Biomolecular Engineering: Theses and Student Research

Renewable fuel technologies aim to mitigate the non-renewability of fossil fuels, challenges with increased energy demand, and the climate impact of fossil fuel emissions. However, before investing in renewable technologies, there need to be decision strategies that assess and identify the best alternatives according to stakeholder priorities. There is also a concern about whether the technologies that are the “most sustainable” effectively meet the acceptable risk requirements of stakeholders. In response to this question, a risk-adapted multi-criteria decision model was developed and compared to a sustainability study that evaluated five renewable diesel technologies, including Green Diesel I, II, and III; …

Attention In The Faithful Self-Explanatory Nlp Models, Mostafa Rafaiejokandan

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Deep neural networks (DNNs) can perform impressively in many natural language processing (NLP) tasks, but their black-box nature makes them inherently challenging to explain or interpret. Self-Explanatory models are a new approach to overcoming this challenge, generating explanations in human-readable languages besides task objectives like answering questions. The main focus of this thesis is the explainability of NLP tasks, as well as how attention methods can help enhance performance. Three different attention modules are proposed, SimpleAttention, CrossSelfAttention, and CrossModality. It also includes a new dataset transformation method called Two-Documents that converts every dataset into two separate documents required by the …

Low Power Multi-Channel Interface For Charge Based Tactile Sensors, Samuel Hansen

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Analog front end electronics are designed in 65 nm CMOS technology to process charge pulses arriving from a tactile sensor array. This is accomplished through the use of charge sensitive amplifiers and discrete time filters with tunable clock signals located in each of the analog front ends. Sensors were emulated using Gaussian pulses during simulation. The digital side of the system uses SAR (successive approximation register) ADCs for sampling of the processed sensor signals.

Adviser: Sina Balkır

A Stacking-Based Misbehavior Detection System In Vehicular Communication Networks, Troy Green

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Over the past few decades communication systems for vehicles have continued to advance. Communications between these vehicles can be classified into safety related and non safety related messages. An example of a safety related message would be one vehicle warning others of an icy road it encountered, where a non safety related communication would be a passenger streaming a movie. In either case it's important to secure the communications so that the system continues to behave as expected. In this thesis we propose a Misbehavior Detection System (MDS), which is a system that monitors messages sent between vehicles, and detects …

A Low-Power, Low-Area 10-Bit Sar Adc With Length-Based Capacitive Dac, Zhili Pan

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

A 2.5 V single-ended 10-bit successive-approximation-register analog-to-digital converter (SAR ADC) based on the TSMC 65 nm CMOS process is designed with the goal of achieving low power consumption (33.63 pJ/sample) and small area (2874 µm^2 ). It utilizes a novel length-based capacitive digital-to-analog converter (CDAC) layout to achieve low total capacitance for power efficiency, and a custom static asynchronous logic to free the dependence on a high-frequency external clock source. Two test chips have been designed and the problems found through testing the first chip are analyzed. Multiple improved versions of the ADC with minor variations are implemented on the …

Learnfca: A Fuzzy Fca And Probability Based Approach For Learning And Classification, Suraj Ketan Samal

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Formal concept analysis(FCA) is a mathematical theory based on lattice and order theory used for data analysis and knowledge representation. Over the past several years, many of its extensions have been proposed and applied in several domains including data mining, machine learning, knowledge management, semantic web, software development, chemistry ,biology, medicine, data analytics, biology and ontology engineering.

This thesis reviews the state-of-the-art of theory of Formal Concept Analysis(FCA) and its various extensions that have been developed and well-studied in the past several years. We discuss their historical roots, reproduce the original definitions and derivations with illustrative examples. Further, we provide …

Bevers: A General, Simple, And Performant Framework For Automatic Fact Verification, Mitchell Dehaven

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Fact verification has become an important process, primarily done manually by humans, to verify the authenticity of claims and statements made online. Increasingly, social media companies have utilized human effort to debunk false claims on their platforms, opting to either tag the content as misleading or false, or removing it entirely to combat misinformation on their sites. In tandem, the field of automatic fact verification has become a subject of focus among the natural language processing (NLP) community, spawning new datasets and research. The most popular dataset is the Fact Extraction and VERification (FEVER) dataset. In this thesis an end-to-end …