Engineering Commons^™

Lattice Dynamics Of Orthorhombic Ndgao3, A. Mock, Rafal Korlacki, Sean Knight, Megan Stokey, A. Fritz, V. Darakchieva, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

A complete set of infrared-active and Raman-active lattice modes is obtained from density functional theory calculations for single-crystalline centrosymmetric orthorhombic neodymium gallate. The results for infraredactive modes are compared with an analysis of the anisotropic long-wavelength properties using generalized spectroscopic ellipsometry. The frequency-dependent dielectric function tensor and dielectric loss function tensor of orthorhombic neodymium gallium oxide are reported in the spectral range of 80–1200 cm⁻¹. A combined eigendielectric displacement vector summation and dielectric displacement loss vector summation approach augmented by considerations of lattice anharmonicity is utilized to describe the experimentally determined tensor elements. All infrared-active transverse and longitudinal …

Your Internet Data Is Rotting, Paul Royster

University of Nebraska-Lincoln Libraries: Faculty Publications

The internet is growing, but old information continues to disappear daily.

Many MySpace users were dismayed to discover earlier this year that the social media platform lost 50 million files uploaded between 2003 and 2015. The failure of MySpace to care for and preserve its users’ content should serve as a reminder that relying on free third-party services can be risky. MySpace has probably preserved the users’ data; it just lost their content. The data was valuable to MySpace; the users’ content less so.

Preserving content or intellectual property on the internet presents a conundrum. If it’s accessible, then it …

Wearable Devices For Single-Cell Sensing And Transfection, Lingqian Chang, Yu-Chieh Wang, Faheem Ershad, Ruiguo Yang, Cunjiang Yu, Yubo Fan

Department of Mechanical and Materials Engineering: Faculty Publications

Wearable healthcare devices are mainly used for biosensing and transdermal delivery. Recent advances in wearable biosensors allow for long-term and real-time monitoring of physiological conditions at a cellular resolution. Transdermal drug delivery systems have been further scaled down, enabling wide selections of cargo, from natural molecules (e.g., insulin and glucose) to bioengineered molecules (e.g., nanoparticles). Some emerging nanopatches show promise for precise single-cell gene transfection in vivo and have advantages over conventional tools in terms of delivery efficiency, safety, and controllability of delivered dose. In this review, we discuss recent technical advances in wearable micro/nano devices with unique capabilities or …

Restricted Crossing U-Turns At Rural Intersections, Timothy Adams

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

This study examines the potential for replacing the standard intersection design at two-way stop control (TWSC) and all-way stop control (AWSC) intersections along rural highways with a roundabout or a restricted crossing u-turn (RCUT) facility. The geometry of the RCUT design prohibits left and through movements from the side road, and provides a u-turn location downstream from the main crossing. This type of facility has been implemented for rural highways extensively in other states and has the potential to serve as a cost-effective solution to improve roadway safety within Nebraska.

Comparative analysis is conducted for three site locations (Humphrey, Madison, …

Application Of Remote Sensing Technology In Water Resources Management, Mahesh Pun

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

The primary goal of this dissertation was to leverage the capabilities of remote sensing technology for capturing detailed spatial information at different spatial resolutions to monitor agricultural crops and generate accurate input datasets for water resources models. This dissertation is divided into three different research studies. In the first study, a remote sensing classification method was developed for classifying irrigated and non-irrigated fields that integrates Vegetation indices with surface energy balance fluxes. The method was applied in the COHYST2010 hydrological model region with wide climate variation and to multiple growing seasons with results that were 92.1% accurate and explained 97% …

Image Processing Algorithms For Elastin Lamellae Inside Cardiovascular Arteries, Mahmoud Habibnezhad

School of Computing: Dissertations, Theses, and Student Research

Automated image processing methods are greatly needed to replace the tedious, manual histology analysis still performed by many physicians. This thesis focuses on pathological studies that express the essential role of elastin lamella in the resilience and elastic properties of the arterial blood vessels. Due to the stochastic nature of the shape and distribution of the elastin layers, their morphological features appear as the best candidates to develop a mathematical formulation for the resistance behavior of elastic tissues. However, even for trained physicians and their assistants, the current measurement procedures are highly error-prone and prolonged. This thesis successfully integrates such …

Full Scale 13-Story Building Implosion And Collapse: Effects On Adjacent Structures, Kanchan Devkota

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

Two dormitory halls at the University of Nebraska-Lincoln known as Cather and Pound halls were demolished via controlled implosion on December 22, 2017. Cather and Pound halls were two thirteen-story reinforced concrete structures. The demolition of these two structures included the implosion of controlled charges at selected columns on alternating floors which initiated the progressive collapse of these structures. Three nearby structures in the vicinity of Cather and Pound halls were instrumented with high sensitivity uniaxial piezoelectric accelerometers to record the response of the adjacent structures during the event of the implosion and the progressive collapse. While these two thirteen-story …

A Data-Driven Approach For Detecting Stress In Plants Using Hyperspectral Imagery, Suraj Gampa

School of Computing: Dissertations, Theses, and Student Research

A phenotype is an observable characteristic of an individual and is a function of its genotype and its growth environment. Individuals with different genotypes are impacted differently by exposure to the same environment. Therefore, phenotypes are often used to understand morphological and physiological changes in plants as a function of genotype and biotic and abiotic stress conditions. Phenotypes that measure the level of stress can help mitigate the adverse impacts on the growth cycle of the plant. Image-based plant phenotyping has the potential for early stress detection by means of computing responsive phenotypes in a non-intrusive manner. A large number …

Outdoor Education Center Concept Site Master Plan And Improvements As Designed By Wingineers, Christina Thibodeau

Honors Program: Senior Projects (Public)

This thesis builds on a basis of four years of engineering education to produce a final project for the capstone course. The idea behind this project was to provide a workable master plan and conceptual site improvements for a real application, the Outdoor Education Center in east Lincoln, Nebraska. The Boy Scouts of America Cornhusker Council and the University of Nebraska – Lincoln Department of Civil Engineering have cooperated throughout the Senior Design capstone course to make this possible for the students involved.

Predictive Modeling Of Fate And Transport Of Three Prevalent Contaminants In Midwest Agroecosystem Surface Waters: Nitrate-N, Atrazine, And Escherichia Coli, Samuel Hansen

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

The majority of streams and rivers in the United States (U.S.) are ecologically impaired, or threatened by anthropogenic stressors. Recent reports have found atrazine in drinking water to be associated with increased birth defects and incidences of Non-Hodgkin’s Lymphoma, with higher levels of significance from exposure to both atrazine and nitrate-N. In contrast, recent illnesses from E. coli contaminating vegetables that originated from irrigation water has increased awareness of identifying sources of E. coli entering irrigation reservoirs.

Methods to accurately predict atrazine and E. coli occurrence and potential sources in waterways continue to limit the identifying appropriate and effective prevention …

Uumanned Aerial Vehicle Data Analysis For High-Throughput Plant Phenotyping, Jiating Li

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

The continuing population is placing unprecedented demands on worldwide crop yield production and quality. Improving genomic selection for breeding process is one essential aspect for solving this dilemma. Benefitted from the advances in high-throughput genotyping, researchers already gained better understanding of genetic traits. However, given the comparatively lower efficiency in current phenotyping technique, the significance of phenotypic traits has still not fully exploited in genomic selection. Therefore, improving HTPP efficiency has become an urgent task for researchers. As one of the platforms utilized for collecting HTPP data, unmanned aerial vehicle (UAV) allows high quality data to be collected within short …

Boy Scouts Of America Concept Site Master Plan And Improvements, Anna Cole, Jacob Chekal, William Seeger, Shanon Al-Brady, Nicholas Cowles

Honors Program: Senior Projects (Public)

Our team, G1 Engineering, has partnered with the Boy Scouts of America to provide an update to their master plan for the Outdoor Education Center site located at 600 S. 120^th Street, Lincoln, NE. Our work included providing transportation solutions; drainage evaluations; investigation of geotechnical conditions; environmental evaluation and determination of permitting requirements; preparation of concept design plans for bridges, drainage, utilities, and overall site plan; and evaluation of structural elements included in the project.

Two streams cross the property presenting site access issues. Our team provided pedestrian, UTV, and emergency vehicle access bridges to address these issues. With …

Bio-Desalination Of Brackish And Seawater Using Halophytic Algae, Endalkachew Sahle-Demessie, Ashraf Aly Hassan, Amro El Badawy

Department of Civil and Environmental Engineering: Faculty Publications

Global demand for water is rising. A sustainable and energy efficient approach is needed to desalinate brackish sources for agricultural and municipal water use. Genetic variation among two algae species, Scenedesmus species (S. sp.) and Chlorella vulgaris (C. vulgaris), in their tolerance and uptake of salt (NaCl) was examined for potential bio-desalination of brackish water. Salt-tolerant hyper-accumulators were evaluated in a batch photobioreactors over salinity concentration ranging from 2 g/L to 20 g/L and different nutrient composition for their growth rate and salt-uptake. During algae growth phase, the doubling time varied between 0.63 and 1.81 days for S …

Field Evidence Of A Natural Capillary Barrier In A Gravel Alluvial Aquifer, Todd Halihan, Ronald B. Miller, David Correll, Derek M. Heeren, Garey A. Fox

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Ozark streams commonly feature “composite” floodplains, in which the vadose zone consists of silt or silt loam soils (?1 m thick) overlying gravel subsoil. Previous work has shown that preferential flow paths can exist within the gravel subsoil, which can conduct water and P at rates exceeding the sorption capacity of the gravel. At a site on Barren Fork Creek, a 1- by 1-m infiltration plot was constructed and an infiltration experiment was performed using sequentially introduced solutes including P (the constituent of regulatory interest), Rhodamine-WT (Rh-WT, a visual tracer), and Cl− (an electrical tracer). The solute transport was measured …

Biofiltration Of Volatile Organic Compounds Emitted At Ethanol Plants, Christopher Arthur Duerschner

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

Ethanol manufacturing is an important and growing sector in the biofuels marketplace. At ethanol plants, the control of volatile organic compound containing emissions from fermentation tanks and distillers dried grains with solubles driers is accomplished through the use of air scrubbers and regenerative thermal oxidizers. The operation of these control units imposes substantial operating costs for the ethanol plant. Biotrickling filters have the ability to replace scrubbers and regenerative thermal oxidizers resulting in significant economic and environmental benefits. Two biotrickling filters were operated in parallel under acetaldehyde loadings ranging from 4 to 136 gm^-3hr^-1. To examine …

Theoretical Model For Shields Diagram And Its Application, Jichao Jiang

Department of Environmental Engineering: Theses and Other Student Research

The transition from the condition of “no motion” to initial sediment moment, defined as sediment initiation, has been related to practical engineering (channel degradation, stable channel design), oceanographic (dredging, pipelines, cables), sedimentologic (sediment mobility, transport rates), geologic (the hydraulic interpretation of paleoenvironments), geochemical (pollutant transport), and gained considerable interest since nineteenth century.

Shields diagram for sediment initiation in terms of critical shear stress is a classic problem in sediment transport, but it is still an empirical law without a simple and practical theory despite extensive research since the 1930s. Hence, this research presents a simple theoretical model for critical shear …

Automated Generation Of Daily Evacuation Paths In 4d Bim, Kyungki Kim, Yong-Cheol Lee

Durham School of Architectural Engineering and Construction: Faculty Publications

Spatial movements of workers and equipment should be carefully planned according to project plans. In particular, it is crucial for workers’ safety to prepare emergency evacuation paths according to changing construction site configurations and construction progress. However, creating evacuation paths for all crews for each day can be an extremely labor-intensive task if it is done manually. Consequently, in most construction projects, evacuation plans are not provided to managers and crews throughout the entire construction. Even state-of-the-art technologies do not suggest ways to generate evacuation paths according to changing progresses presented in 4-Dimensional Building Information Model (4D BIM). This research …

Driving Performances Assessment Based On Speed Variation Using Dedicated Route Truck Gps Data, Ying Li, Li Zhao, Laurence R. Rilett

Department of Civil and Environmental Engineering: Faculty Publications

It was hypothesized that a driver is not safe when travel speed is too high and also not necessarily safe when travel speed is too low. Based on this hypothesis, this paper studied the risky driving performances by measuring speed variations of a driver’s recurrent trips in two perspectives: 1) driver profiles, which scored the risk on-road driving of each driver and 2) driving patterns, which reflected the risk speed patterns of a type of drivers. The proposed method was tested on a 30-day global positioning system (GPS) dataset, collected from 100 trucks. The study first split the raw dataset …

Influence Of Metal Additives On Microstructure And Properties Of Amorphous Metal–Sioc Composites, Kaisheng Ming, Qing Su, Chao Gu, Dongyue Xie, Yongqiang Wang, Michael Nastasi, Jian Wang

Department of Mechanical and Materials Engineering: Faculty Publications

Strong, ductile, and irradiation-tolerant structural materials are in urgent demand for improving the safety and efficiency of advanced nuclear reactors. Amorphous ceramics could be promising candidates for high irradiation tolerance due to thermal stability and lack of crystal defects. However, they are very brittle due to plastic flow instability. Here, we realized enhanced plasticity of amorphous ceramics through compositional and microstructural engineering. Two metal–amorphous ceramic composites, Fe-SiOC and Cu-SiOC, were fabricated by magnetron sputtering. Iron atoms are preferred to form uniformly distributed nano-sized Fe-rich amorphous clusters, while copper atoms grow non-uniformly distributed nano-crystalline Cu particles. The Fe-SiOC composite exhibits high …

Unl-Cc Outdoor Education Center Master Plan, Marie Wagner

Honors Program: Senior Projects (Public)

The following report contains the work done by the group Griswold Engineering in completion of the Senior Design requirements for Civil Engineering and the Honors Requirements of the Project Manager. As the project manager, my job was to organize the project as a whole and to work alongside the Structural Engineer on the project. One of the main problems to overcome was the division of labor amongst the group. The project was originally conceived as a group project with one project manager and five other students to serve as the project engineers in each subdiscipline. Since this group only had …

Development Of A Mash Tl-4 Steel, Side-Mounted, Beam-And-Post, Bridge Rail, Oscar Pena

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

A new steel, side-mounted, beam-and-post, bridge rail was designed, crash-tested, and evaluated according to safety performance guidelines included in the American Association of State Highway and Transportation Officials Manual for Assessing Safety Hardware (MASH) for Test Level 4 (TL-4). The new bridge rail system was designed to be compatible to multiple concrete bridge decks utilized by the States of Illinois and Ohio. Bridge rail configurations were designed and optimized based on weight per foot, constructability, and safety. Post-to-rail and rail-to-rail connections were designed for the new bridge rail. Several concepts for these connections were configured, and after discussion with representatives …

Development Of Post-To-Deck Connections For Use In A Mash Tl-4 Steel-Tube Bridge Rail, Pascual Mauricio

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

A new post-to-deck connection was designed for mounting an upcoming Manual for Assessing Safety Hardware (MASH) Test Level 4 steel-tube bridge rail to the side of the bridge deck to limit impact load transferred to the deck and to minimize the propensity for deck damage during impacts. With preference for the bridge rail system to be compatible for use on all deck configurations, the Illinois and Ohio Departments of Transportation desired the new system to attach to bridge decks comprised of concrete slabs or precasted prestressed, concrete box-beam girders.

A new post-to-deck connection for a new MASH 2016 TL-4 steel-tube …

Low-Dimensional Materials With Protective Coatings For Applications Under Extreme Conditions, Qiming Zou

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

Traditional ceramic-based, conductive materials used under extreme conditions are severely limited due to their conditional electrical conductivity and poor stability under harsh circumstances. Advanced composite structures based on vertically aligned carbon nanotubes (VACNTs) and high-temperature ceramics are expected to address this grand challenge, in which ceramic serves as a shielding layer protecting the VACNTs from the oxidation and erosive environment, while the VACNTs work as a conductor. However, it is still a great challenge to fabricate VACNT/ceramic composite structures due to the limited infiltration of ceramics inside the VACNT arrays. Hence developing a feasible method to infiltrate ceramics into VACNT …

Program And Proceedings: Nebraska Academy Of Sciences 1880–2019, 139th Anniversary Year, One Hundred-Twenty-Ninth Annual Meeting, April 12, 2019

Nebraska Academy of Sciences: Programs and Proceedings

Program

Aeronautics and Space Science

Collegiate Academy: Biology

Biological and Medical Sciences

Chemistry and Physics

Teaching and Learning the Dynamics of Cellular Respiration Using Interactive Computer Simulations Workshop

Life After College: Building Your Resume for the Future Workshop

Collegiate Academy: Chemistry and Physics

Aeronautics and Space Science, Poster Session

Maiben Memorial Lecture: David Swanson

Anthropology

Applied Science and Technology

Earth Science

Environmental Sciences

Teaching of Science and Math

Biomechanical Foot Guidance Linkage, Carl Nelson, Cale J. Stolle, Judith M. Burnfield

Department of Mechanical and Materials Engineering: Faculty Publications

A gait replication apparatus can include a scalable mechanical mechanism configured to replicate different gaits . The scalable mechanical mechanism can include , for example , a four - bar linkage , a pantograph , a cam / Scotch - yoke mechanism , and so forth . In some embodiments , the mechanical mechanism includes a beam rotating about an axis passing proximate to its center , with a foot pedal slidably coupled with the beam , and a timing chain / belt or cable pulley - pair coupled with the foot pedal and looped about the beam . A …

Electrically Conductive Concrete Mix For Electromagnetic (Em) Ground Plane, Christopher Tuan, Lim Nguyen

Department of Civil and Environmental Engineering: Faculty Publications

Conductive concrete mixtures are described that are configured to reflect, for instance, EM waves propagating from an EM pulser onto the conductive concrete mixture forming a ground plane, rather than absorb or dissipate the electromagnetic energy. The conductive concrete mixtures include cement, aggregate, water, metallic conductive material, and conductive carbon particles.

A Strategic Audit Of Nintendo Co., Ltd., Emily Wagner

Honors Program: Senior Projects (Public)

The astounding success of the Nintendo Switch since its launch in March 2017 has brought Nintendo back into the spotlight of the gaming industry. However, what strategies led to the Switch’s success, enabling Nintendo to come back from the complete and utter failure of the Wii U? Also, what does Nintendo need to do to maintain its success over the lifetime of the Switch and beyond? This paper offers a strategic analysis of Nintendo, examining the company’s history, recent products, competitive advantages, and reasons for the success of the Switch. It also provides an analysis of Nintendo’s internal and external …

Civil Engineering Design Of Cornhusker Council's Outdoor Education Center, Kelly Weiler

Honors Program: Senior Projects (Public)

A team of geotechnical, structural, hydraulic, environmental, and transportation experts collaborated to provide engineering solutions to the Cornhusker Council in an effort to solve the current problems facing their Outdoor Education Center. This results of this project provided the structural design of three bridges on the property, transportation plans for two parking lots and roadway design, geotechnical recommendations for soil testing and erosion prevention, and an environmental and hydraulic analysis of the property. A major challenge in the design of this project is the consideration of the dangers and regulations that accompany the floodway and floodplain regions on site. Various …

Aerial Base Station Deployment For Post-Disaster Public Safety Applications, Jose Antonio Matamoros Vargas

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

Earthquakes and floods are constant threats to most of the countries in the world. After such catastrophes, a rapid response is needed, which includes communications not only for first responders but also for local civilians. Even though there are technologies and specialized personnel for rapid deployment, it is common that external factors will hinder the arrival of help while communication requirements are urgently required. Such communication technologies would aid tasks regarding organization and information dissemination from authorities to the civilians and vice-versa. This necessity is due to protocols and applications to allocate the number of emergency resources per location and …

Analysis Of Local Anti-Islanding Detection Methods For Photovoltaic Generators In Distribution Systems, Milad Kahrobaee

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

In the current decade, technology innovations and cost reduction of inverter-based Distributed Energy Resources (DERs) have led to higher integration of distributed energy storage and photovoltaic (PV) solar power systems. Increasing growth in PV penetration to the distribution system can raise operational and safety concerns especially in case of an unintended islanding.

In general, standards require distributed generators (DGs) to detect islanding from the main grid and cease to energize the local system. Multiple methods have been introduced in the literature to detect these islands reliably and quickly. In order to connect an inverter to distribution system, inverter should pass …