Engineering Commons^™

Soil Health Effects And Stakeholder Perceptions Of Manure And Woody Biomass Application To Cropland In Nebraska, Linda R. Schott

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

Organic products that have historically been viewed as waste products may improve soil health by adding carbon (C) and nutrients to soil. Two such products are woodchips, generated from forest or rangeland management activities, and livestock manure. In Nebraska, eastern redcedar (Juniperus virginiana L.) is a native but invasive tree species inhibiting rangeland productivity. Livestock manure that is underutilized while inorganic fertilizers are imported for crop production presents a water quality risk by contributing to local- and regional-scale nutrient imbalances. Increasing the responsible use of livestock manure in crop fertility programs to improve sustainability of both livestock and crop farms …

Generation Of 360 Degree Point Cloud For Characterization Of Morphological And Chemical Properties Of Maize And Sorghum, Suresh Thapa

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

Recently, imaged-based high-throughput phenotyping methods have gained popularity in plant phenotyping. Imaging projects the 3D space into a 2D grid causing the loss of depth information and thus causes the retrieval of plant morphological traits challenging. In this study, LiDAR was used along with a turntable to generate a 360-degree point cloud of single plants. A LABVIEW program was developed to control and synchronize both the devices. A data processing pipeline was built to recover the digital surface models of the plants. The system was tested with maize and sorghum plants to derive the morphological properties including leaf area, leaf …

Variable Rate Irrigation Using A Spatial Evapotranspiration Model With Remote Sensing Imagery And Soil Water Content Measurements, Sandeep Bhatti

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

Variable rate irrigation may help in intensification of agriculture by producing more yield per unit inputs. Real time spatial information about water balance components is important for designing VRI prescription maps. This work involved use of a spatial evapotranspiration model for studying spatial variability in an agricultural field at the Eastern Nebraska Research and Extension Center near Mead, Nebraska. Imagery from unmanned aerial systems and Landsat were used as input for the spatial evapotranspiration model. Other inputs into the model were soil water content measurements from neutron probes, weather data, crop data, previous irrigation prescriptions, and soil properties for the …

Environmental Fate And Microbial Effects Of Monensin, Lincomycin, And Sulfamethazine Residues In Soil, Matteo D'Alessio, Lisa M. Durso, Daniel N. Miller, Brian Woodbury, Chittaranjan Ray, Daniel D. Snow

Nebraska Water Center: Faculty Publications

The impact of commonly-used livestock antibiotics on soil nitrogen transformations under varying redox conditions is largely unknown. Soil column incubations were conducted using three livestock antibiotics (monensin, lincomycin and sulfamethazine) to better understand the fate of the antibiotics, their effect on nitrogen transformation, and their impact on soil microbial communities under aerobic, anoxic, and denitrifying conditions. While monensin was not recovered in the effluent, lincomycin and sulfamethazine concentrations decreased slightly during transport through the columns. Sorption, and to a limited extent degradation, are likely to be the primary processes leading to antibiotic attenuation during leaching. Antibiotics also affected microbial respiration …

Deploying, Improving And Evaluating Edge Bundling Methods For Visualizing Large Graphs, Jieting Wu

School of Computing: Dissertations, Theses, and Student Research

A tremendous increase in the scale of graphs has been witnessed in a wide range of fields, which demands efficient and effective visualization techniques to assist users in better understandings of large graphs. Conventional node-link diagrams are often used to visualize graphs, whereas excessive edge crossings can easily incur severe visual clutter in the node-link diagram of a large graph. Edge bundling can effectively remedy visual clutter and reveal high-level graph structures. Although significant efforts have been devoted to developing edge bundling, three challenging problems remain. First, edge bundling techniques are often computationally expensive and are not easy to deploy …

Asic Design To Support Low Power High Voltage Power Supply For Radiation Monitoring Applications, Daniel Rogge

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

A low power high voltage power supply is designed for use in a long duration radiation monitoring system. The supply employs a flexible pulse frequency modulation switching controller implemented in a 0.35 $\mu$m CMOS technology. The controller drives and regulates a flyback transformer driven 12-stage Cockroft-Walton voltage multiplier chain. The chain provides bias for the dynodes of a photomultiplier tube. The supply voltage is selectable via a 12-bit on-chip digital to analog converter. The system is designed for low power operation and immunity to supply voltage variation as the application is battery-powered.

Advisors: Sina Balkir and Michael W. Hoffman

Evoalloy: An Evolutionary Approach For Analyzing Alloy Specifications, Jianghao Wang

School of Computing: Dissertations, Theses, and Student Research

Using mathematical notations and logical reasoning, formal methods precisely define a program’s specifications, from which we can instantiate valid instances of a system. With these techniques, we can perform a variety of analysis tasks to verify system dependability and rigorously prove the correctness of system properties. While there exist well-designed automated verification tools including ones considered lightweight, they still lack a strong adoption in practice. The essence of the problem is that when applied to large real world applications, they are not scalable and applicable due to the expense of thorough verification process. In this thesis, I present a new …

Controller Evolution And Divergence: A Software Perspective, Balaji Balasubramaniam

School of Computing: Dissertations, Theses, and Student Research

Successful controllers evolve as they are refined, extended, and adapted to new systems and contexts. This evolution occurs in the controller design and also in its software implementation. Model-based design and controller synthesis can help to synchronize this evolution of design and software, but such synchronization is rarely complete as software tends to also evolve in response to elements rarely present in a control model, leading to mismatches between the control design and the software.

In this thesis, we perform a first-of-its-kind study on the evolution of two popular open-source safety-critical autopilot control software -- ArduPilot, and Paparazzi, to better …

Experimental Study On A New Type Of Transverse Connection For Nebraska County Bridge System, Alexander Bleyhl

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

Many county-owned bridges in Nebraska need replacement due to their structural deficiency. Most of the bridges needing replacement are in the 40 to 60 ft range. This span range lacks a standard design that fits Nebraska county practices in terms of speed and simplicity of construction. The current systems being used are (a) Precast 1 by 2 ft planks which can span up to 30 ft, (b) Cast-in-place slab bridges which can span up to 50 ft but require extensive field formwork, concrete placing, and curing, and are best when constructed in three-span units, and (c) Inverted tees which can …

Drop Generation Using Cross-Flow In Rigid Body Rotation, Haipeng Zhang

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

Inspired by crossflow membrane droplet generation and microfluidic droplet generation, I propose an easy method to generate monodisperse drops using cross-flow caused by rigid body rotation. In this approach, a dispersed phase (DP) liquid was injected through a stationary vertical needle into an immiscible continuous phase (CP) liquid which was in rigid body rotation. A DP drop growing at the end of the needle experienced fluid dynamic forces from the horizontal CP flow, and it was detached from the needle when it had grown to a certain size. This study investigated the relationship between the resultant size of drops and …

Investigation Of A Tractor-Tank Trailer Roadside Containment Barrier, Dean L. Whitfield

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

The objective of this research project was to develop a new, cost-effective, Manual for Assessing Safety Hardware (MASH) Test Level 6 (TL-6) barrier. A literature review on prior Test Level 5 and Test Level 6 barriers was conducted, and the cost of current TL-5 and TL-6 barriers was established. Existing and modified design procedures for roadside barrier were reviewed as well as current TL-6 design forces. A preliminary TL-6 truck model was developed in LS-DYNA. The minimum barrier height to contain a tractor-tank vehicle was determined to be 62 in. for a rigid, vertical-faced barrier through LS-DYNA computer simulation. New …

Water, Energy, And Carbon Footprints Of Bioethanol From The U.S. And Brazil, Mesfin Mekonnen, Thiago L. Romanelli, Chittaranjan Ray, Arjen Y. Hoekstra, Adam Liska, Christopher M. U. Neale

Adam Liska Papers

Driven by biofuel policies, which aim to reduce greenhouse gas (GHG) emissions and increase domestic energy supply, global production and consumption of bioethanol have doubled between 2007 and 2016, with rapid growth in corn-based bioethanol in the U.S. and sugar cane-based bioethanol in Brazil. Advances in crop yields, energy use efficiency in fertilizer production, biomass-to-ethanol conversion rates, and energy efficiency in ethanol production have improved the energy balance and GHG emission reduction potential of bioethanol. In the current study, the water, energy, and carbon footprints of bioethanol from corn in the U.S. and sugar cane in Brazil were assessed. The …

System And Methods For Ventilation Through A Body Cavity, Mark A. Borden, Benjamin S. Terry

Department of Mechanical and Materials Engineering: Faculty Publications

A system and methods for the delivery of oxygen through a body cavity of a subject using oxygen microbubbles . Through circulation of oxygen microbubbles through the body cavity , oxygen and carbon dioxide exchange may occur . Overall improvement in extending survival rate time during emergency situations caused by pulmonary or similar oxygen - intake restricting injury and / or failure may be achieved through use of the invented system and methods .

Evaluation Of The Weak Constraint Data Assimilation Approach For Estimating Turbulent Heat Fluxes At Six Sites, Xinlei He, Tongren Xu, Sayed M. Bateni, C.M.U. Neale, Thomas Auligne, Shaomin Liu, Kaicun Wang, Kebiao Mao, Yunjun Yao

Daugherty Water for Food Global Institute: Faculty Publications

A number of studies have estimated turbulent heat fluxes by assimilating sequences of land surface temperature (LST) observations into the strong constraint-variational data assimilation (SC-VDA) approaches. The SC-VDA approaches do not account for the structural model errors and uncertainties in the micrometeorological variables. In contrast to the SC-VDA approaches, the WC-VDA approach (the so-called weak constraint-VDA) accounts for the effects of structural and model errors by adding a model error term. In this study, the WC-VDA approach is tested at six study sites with different climatic and vegetative conditions. Its performance is also compared with that of SC-VDA at the …

Web-Based Archaeology And Collaborative Research, Fabrizio Galeazzi, Heather Richards-Rissetto

Department of Anthropology: Faculty Publications

While digital technologies have been part of archaeology for more than fifty years, archaeologists still look for more efficient methodologies to integrate digital practices of fieldwork recording with data management, analysis, and ultimately interpretation.This Special Issue of the Journal of Field Archaeology gathers international scholars affiliated with universities, organizations, and commercial enterprises working in the field of Digital Archaeology. Our goal is to offer a discussion to the international academic community and practitioners. While the approach is interdisciplinary, our primary audience remains readers interested in web technology and collaborative platforms in archaeology

Effects Of Moving Bottlenecks On Traffic Operations On Four-Lane Level Freeway Segments, Jianan Zhou

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

The Highway Capacity Manual (HCM) was developed to provide capacity and level of service analyses for roadway facilities. Trucks may adversely affect the quality of traffic flow on a roadway. In HCM, the passenger car equivalent (PCE) of a truck, which represents the number of passenger cars that have an equivalent effect on traffic flow, is used to account for the impacts of trucks. However, in the past ten years rural freeways in the western rural U.S. have experienced conditions that lie outside the standard HCM conditions. Also, the current HCM truck PCEs may not be appropriate for the western …

Using Low Power 5g Iot Devices Off-Network Utilizing Modified Prose Communication, John Aaron Swarner

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

In setups to enable IoT devices, high power radios are required in each of the devices separately. In order to reduce the power requirements for each individual device, a lower power radio could be used in order to reduce the total power requirements and size for the device and increase battery life or reduce power draws for each device. To enable this, a small change removing the application server requirements would be required. A mesh network could be used to enable communication to the main network, either to a tower that is within the range or through a larger relay …

Supporting Diverse Customers And Prioritized Traffic In Next-Generation Passive Optical Networks, Naureen Hoque

School of Computing: Dissertations, Theses, and Student Research

The already high demand for more bandwidth usage has been growing rapidly. Access network traffic is usually bursty in nature and the present traffic trend is mostly video-dominant. This motivates the need for higher transmission rates in the system. At the same time, the deployment costs and maintenance expenditures have to be reasonable. Therefore, Passive Optical Networks (PON) are considered promising next-generation access technologies. As the existing PON standards are not suitable to support future-PON services and applications, the FSAN (Full Service Access Network) group and the ITU-T (Telecommunication Standardization Sector of the International Telecommunication Union) have worked on developing …

A Comprehensive Framework To Replicate Process-Level Concurrency Faults, Supat Rattanasuksun

School of Computing: Dissertations, Theses, and Student Research

Concurrency faults are one of the most damaging types of faults that can affect the dependability of today’s computer systems. Currently, concurrency faults such as process-level races, order violations, and atomicity violations represent the largest class of faults that has been reported to various Linux bug repositories. Clearly, existing approaches for testing such faults during software development processes are not adequate as these faults escape in-house testing efforts and are discovered during deployment and must be debugged.

The main reason concurrency faults are hard to test is because the conditions that allow these to occur can be difficult to replicate, …

Developing Serious Games In Engineering Education: Innovation At The Nexus Of Food, Energy, And Water Systems, Nathan Rice

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

At a time when food, energy, and water (FEW) are of the utmost concern to the security and health of the world, an initiative has begun to understand the interactions between these systems. The goal of Innovation at the Nexus of Food, Energy, and Water Systems (INFEWS) is to bring together research fields that typically work in their own silos to solve complex problems increasing the resiliency and sustainability of the FEW system. Stemming from this initiative was a project to produce an educational immersive simulation game to teach youth about how their food is produced, systems thinking, and sustainable …

Understanding Electricity Bills: Guidance For Nebraska Businesses And Municipalities, Elizabeth M. Regier, Bruce I. Dvorak

Department of Civil and Environmental Engineering: Faculty Publications

This publication is intended to help business owners and municipal managers understand the different types of charges in their electricity bills. By understanding these charges, they may be able to identify ways to reduce their electricity costs.

Statistical Investigation Of Road And Railway Hazardous Materials Transportation Safety, Amirfarrokh Iranitalab

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

Transportation of hazardous materials (hazmat) in the United States (U.S.) constituted 22.8% of the total tonnage transported in 2012 with an estimated value of more than 2.3 billion dollars. As such, hazmat transportation is a significant economic activity in the U.S. However, hazmat transportation exposes people and environment to the infrequent but potentially severe consequences of incidents resulting in hazmat release. Trucks and trains carried 63.7% of the hazmat in the U.S. in 2012 and are the major foci of this dissertation. The main research objectives were 1) identification and quantification of the effects of different factors on occurrence and …

Effect Of Swine Manure Pit Additives And Facility Disinfectants On The Fate Of Antibiotics And Manure Composition During Simulated Swine Manure Slurry Storage, Jon Duerschner

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

This thesis investigates the effect of time and of swine manure slurry treatment on the physical properties, nutrient content, and the concentrations of antibiotics chlortetracycline, lincomycin, and tiamulin in simulated storage of swine manure. In one experiment the slurry was treated with six additive products. In a second experiment a set of four disinfectant products were used. Control consisted of unamended slurry. Manure was stored in 60 liter stainless steel bioreactors to simulate deep pit storage and was sampled 7 times over a 40 day incubation.

From an ANOVA of the results, it was concluded that evaporation may be contributing …

Invasion Of The P Elements: Tolerance Is Not Futile, Colin D. Meiklejohn, Justin P. Blumenstiel

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Organisms are locked in an eternal struggle with parasitic DNA sequences that live inside their genomes and wreak havoc on their host’s chromosomes as they spread through populations. To combat these parasites, host species have evolved elaborate mechanisms of resistance that suppress their activity. A new study in Drosophila indicates that, prior to the acquisition of resistance, individuals can vary in their ability to tolerate the activity of these genomic parasites, ignoring or repairing the damage they induce. This tolerance results from variation at genes involved in germline development and DNA damage checkpoints and suggests that these highly conserved cellular …

Fungi: A Neglected Candidate For The Application Of Self-Healing Concrete, Congrui Jin, Rui Yu, Zhonghe Shui

Department of Civil and Environmental Engineering: Faculty Publications

Self-healing mechanism in concrete has been so far achieved mainly by three approaches: autogenous healing, encapsulation of polymeric material, and biologically induced mineralization of calcium carbonate. The microbial approach prevails over the other two approaches due to the high compatibility between the filler material and the concrete compositions. Although the term “microbe” refers to many different types of organisms, research work on self-healing concrete has been so far restricted to bacteria. In this perspective article, we review the current status of bacteria-mediated self-healing concrete and summarize the prospects for future advances. In particular, we point out that fungi may have …

Optical Wireless Data Center Networks, Abdelbaset S. Hamza

School of Computing: Dissertations, Theses, and Student Research

Bandwidth and computation-intensive Big Data applications in disciplines like social media, bio- and nano-informatics, Internet-of-Things (IoT), and real-time analytics, are pushing existing access and core (backbone) networks as well as Data Center Networks (DCNs) to their limits. Next generation DCNs must support continuously increasing network traffic while satisfying minimum performance requirements of latency, reliability, flexibility and scalability. Therefore, a larger number of cables (i.e., copper-cables and fiber optics) may be required in conventional wired DCNs. In addition to limiting the possible topologies, large number of cables may result into design and development problems related to wire ducting and maintenance, heat …

Datanet: Deep Learning Based Encrypted Network Traffic Classification In Sdn Home Gateway, Pan Wang, Feng Ye, Xuejiao Chen, Yi Qian

Department of Electrical and Computer Engineering: Faculty Publications

A smart home network will support various smart devices and applications, e.g., home automation devices, E-health devices, regular computing devices, and so on. Most devices in a smart home access the Internet through a home gateway (HGW). In this paper, we propose a software-defined network (SDN)-HGW framework to better manage distributed smart home networks and support the SDN controller of the core network. The SDN controller enables efficient network quality-of-service management based on real-time traffic monitoring and resource allocation of the core network. However, it cannot provide network management in distributed smart homes. Our proposed SDN-HGW extends the control to …

Birefringence Imaging Chromatography Based On Highly Ordered 3d Nanostructures, Mathias M. Schubert, Tino Hofmann, David S. Hage, Erika Pfaunmiller, Craig M. Herzinger, John A. Woollam, Stefan Schoeche

Department of Electrical and Computer Engineering: Faculty Publications

Ellipsometers and polarimeters or the like to investigate analyte containing fluids applied to a substrate - stage having a multiplicity of nano - structures that project non - normal to a surface thereof , including dynamics of interaction there with , to the end of evaluating and presenting at least partial Jones or Mueller Matricies corresponding to a multiplicity of locations over an imaged area .

Hemodynamics And Pathology Of An Enlarging Abdominal Aortic Aneurysm Model In Rabbits, Hongmei Chen, Yonghua Bi, Siyeong Yu, Linxia Gu, Xiaoyan Zhu, Xinwei Han

Department of Mechanical and Materials Engineering: Faculty Publications

Hemodynamics may play an essential role in the initiation and progression of abdominal aortic aneurysm (AAA). We aimed to study the mechanism of self-healing process by the changes of hemodynamics and pathology in an enlarging AAA in rabbits. Seventy-two rabbits were randomly divided into three groups. Rabbits underwent extrinsic coarctation and received a 10-minute elastase incubation in Group A and Group B. Absorbable suture used in Group A was terminated by balloon dilation at week 4. Diameter was measured after 1, 3, 5, and 15 weeks, computational fluid dynamics analysis was performed at week 3 and week 15. Rabbits were …

Techniques To Stimulate And Interrogate Cell–Cell Adhesion Mechanics, Ruiguo Yang, Joshua A. Broussard, Kathleen J. Green, Horacio D. Espinosa

Department of Mechanical and Materials Engineering: Faculty Publications

Cell–cell adhesions maintain the mechanical integrity of multicellular tissues and have recently been found to act as mechanotransducers, translating mechanical cues into biochemical signals. Mechanotransduction studies have primarily focused on focal adhesions, sites of cell-substrate attachment. These studies leverage technical advances in devices and systems interfacing with living cells through cell–extracellular matrix adhesions. As reports of aberrant signal transduction originating from mutations in cell–cell adhesion molecules are being increasingly associated with disease states, growing attention is being paid to this intercellular signaling hub. Along with this renewed focus, new requirements arise for the interrogation and stimulation of cell–cell adhesive junctions. …