Engineering Commons^™

Assessing Gait And Postural Stability Of Construction Workers Using Wearable Wireless Sensor Networks, Houtan Jebelli

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Falling accidents are a leading cause of fatal and nonfatal injuries in the construction industry. This fact demonstrates the need for a comprehensive fall-risk analysis that incorporates the effects of construction workers’ physiological characteristics. In this context, the objective of the thesis is to investigate and validate the usefulness of the gait- and postural-stability metrics in assessing construction workers’ fall risks. Diverse metrics that assess the capability to keep the body balanced and maintain coordination of body segments during locomotion (gait stability) and stationary postures (postural stability) have been introduced and used in clinical applications. However, their usefulness in the …

Design Of An Improved Post For Use In A Non-Proprietary High-Tension Cable Median Barrier, Robert W. Bielenberg, Ronald K. Faller, Karla A. Lechtenberg, Tyler L. Schmidt, Scott K. Rosenbaugh, John D. Reid, Dean L. Sicking

Nebraska Department of Transportation: Research Reports

The objective of this research study was to develop a revised post section for the non-proprietary high-tension cable median barrier that improved the safety and function of the post by lowering strong-axis forces. A total of twenty dynamic component tests were performed, along with one cable pull test – ten tests with the 7-gauge C-section post, eight with the 10-gauge C-Section posts, and three with the Midwest Weak Post (MWP). The tests were conducted with the posts installed in either a compacted, crushed limestone soil or a rigid sleeve in order to determine the force vs. deflection and energy vs. …

Modeling The Contributions Of Hand Loads To Cervical Spine Compressive Forces, Mohamed R.S. Amar

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

The purpose for this study is threefold. All involve single handed lifting tasks where the height of the lifted object, the distance of the lifted object from the body, and the angle of the lift relative to the body were varied. First, examine the activity of each of the shared musculature of selected shared muscles between the shoulder and cervical spine. Second, attempt to empirically model the activations of the shared muscles. Third, to understand the relationship between the active and antagonistic contraction. Finally, to establish a biomechanical model to estimate the compressive forces on the cervical spine.

Ten subjects …

Controller Area Network (Can) Bus J1939 Data Acquisition Methods And Parameter Accuracy Assessment Using Nebraska Tractor Test Laboratory Data, Samuel E. Marx

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

Electronics have become a standard in agricultural equipment and the trend of “smarter” equipment is on the rise. To have “smarter” equipment, a working knowledge of the accuracy of the data being transmitted throughout that equipment is needed. The controller area network (CAN) bus is the current interface to machine operation data transmitted between electronic control units (ECUs).

Because CAN bus has been around for nearly thirty years, numerous devices have been created for interfacing with the bus. Choosing a device can be a challenge, especially without knowing if there are differences between the logging methods for true data representation. …

Use Of Precisely Sculptured Thin Film (Stf) Substrates With Generalized Ellipsometry To Determine Spatial Distribution Of Adsorbed Fibronectin To Nanostructured Columnar Topographies And Effect On Cell Adhesion, Tadas Kasputis, Alex Pieper, Keith Brian Rodenhausen, Daniel Schmidt, Derek Sekora, Charles Rice, Eva Schubert, Mathias Schubert, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Sculptured thin film (STF) substrates consist of nanocolumns with precise orientation, intercolumnar spacing, and optical anisotropy, which can be used as model biomaterial substrates to study the effect of homogenous nanotopographies on the three-dimensional distribution of adsorbed proteins. Generalized ellipsometry was used to discriminate between the distributions of adsorbed FN either on top of or within the intercolumnar void spaces of STFs, afforded by the optical properties of these precisely crafted substrates. Generalized ellipsometry indicated that STFs with vertical nanocolumns enhanced total FN adsorption two-fold relative to flat control substrates and the FN adsorption studies demonstrate different STF characteristics influence …

Energy Harvesting And Storage: The Catalyst To The Power Constraint For Leveraging Internet Of Things (Iot) On Trains, Kelechi Nwogu

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

The success of Wireless Sensor Networks is heavily constrained by its reliance on storage technology like batteries, which are a finite resource. Whilst the number of transistors in an IC doubles every 18 months, the energy density of batteries is relatively flat during the same time period. This is a key challenge in leveraging the Internet of Things on trains.

The gravity of this problem is increased by an order of magnitude when the network is to be scaled up to hundreds or thousands of nodes. Comprehensive research and development efforts have been devoted to building ultra-low power sensors. These …

Velocity Distributions And Wall Pressures In A Scale Model Gated Box Culvert Control Structure, Alexander L. Evans

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

The South Florida Water Management District (SFWMD) manages a system of canals and structures that control the flow through several large storm water treatment areas (STA). The present project was initiated because of the partial failure of a three-barrel, gated box culvert structure that belongs to the system. The structure has a forebay with three sluice gates that control the flow into three 8 ft by 8 ft box culverts. Settling and partial failure of the culverts in the structure was presumably caused by piping of sediment through joints in pre-cast sections of culvert. It was hypothesized that both unsteady …

Mitochondrial Dysfunction And Loss Of Glutamate Uptake In Primary Astrocytes Exposed To Titanium Dioxide Nanoparticles, Christina L. Wilson

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

The proper function of astrocytes is critical for brain health as they are the most abundant cells in the brain which monitor ion homeostasis, recycle neurotransmitters and respond to tissue damage therefore disruption in astrocyte function can result in overall detrimental effects and has been linked with neurodegenerative diseases. Titanium Dioxide (TiO₂) nanoparticles are currently the second most produced engineered nanomaterial in the world with vast usage in consumer products leading to recurrent human exposure. Animal studies indicate significant nanoparticle accumulation in the brain while cellular toxicity studies demonstrate negative effects on neuronal cell viability and function. However, …

Using Controlled Curing In A Custom Stereolithography-Based 3d Printing Machine To Obtain Graded Property Variations, Evan S. Schwahn

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

In an effort to construct materially graded parts, a strategy was studied that is based on varying ratios of interpenetrating polymer networks (IPNs) in a manner that can be adapted to 3D printing. Using IPNs has the benefit of allowing access to a broad range of property variation. The strategy used involves controlled partial curing of the first network, followed by washing of that network to remove uncured components, then swelling of the structure with a second polymer component and curing.

This method was utilized to control final IPN properties by controlling the extent of crosslinking of the initial network, …

Ultrahigh Density Sub-10 Nm Cobalt Nanowire Arrays: Simulation, Fabrication, And Characterization, Yuan Tian

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

The simulation, fabrication, and characterization of self-assembled ultrahigh density sub-10nm Co nanowire arrays are presented in this dissertation. The general phase separation nanowire growth simulation was operated based on a modified Ising model. The fabrication process can be summarized as the binary Co-X systems lateral phase separation during physical vapor deposition – the plasma layer deposition with a single alloy Co-X target. The “X” stands for Al or Si. The nanowire fabrication and diameter deduction was achieved by balancing the growth rate and surface diffusivity. For Co-Al binary system, the formed sub-10 nm Co nanowires are of face-centered cubic structure …

Robust And Real-Time Stereo Matching On Parallel Graphics Hardware Using Gradient-Based Disparity Refinement, Jedrzej Kowalczuk

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

Computer vision attempts to provide camera-equipped machines with visual perception, i.e., the capability to comprehend their surroundings through the analysis and understanding of images. The ability to perceive depth is a vital component of visual perception that enables machines to interpret the three-dimensional structure of their surroundings and allows them to navigate through the environment. In computer vision, depth perception is achieved via stereo matching, a process that identifies correspondences between pixels in images acquired using a pair of horizontally offset cameras. It is possible to calculate depths from correspondences or, more specifically, the positional offsets (disparities) between pixels in …

Best Practices For Winter Maintenance Roadway Deicer Applications In The State Of Nebraska, Tregan P. D. Albers Ii

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

The cost of deicing chemicals is a significant part of the Nebraska Department of Road’s winter maintenance budget. The objectives of this research are to review literature to determine current winter maintenance practices, analyze and present information gathered in a survey of winter maintenance professionals across Nebraska, and correlate this information with data obtained via MDSS (Maintenance Decision Support System) software to determine current practices being used in the state of Nebraska. Best practices for winter maintenance deicer applications for rural city and county officials in Nebraska are recommended. An explanation of the development of the survey that winter maintenance …

Microstructure And Phase Analysis In Mn–Al And Zr–Co Permanent Magnets, Michael J. Lucis

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

In America’s search for energy independence, the development of rare-earth free permanent magnets is one hurdle that still stands in the way. Permanent magnet motors provide a higher efficiency than induction motors in applications such as hybrid vehicles and wind turbines. This thesis investigates the ability of two materials, Mn-Al and Zr-Co, to fill this need for a permanent magnet material whose components are readily available within the U.S. and whose supply chain is more stable than that of the rare-earth materials. This thesis focuses on the creation and optimization of these two materials to later be used as the …

Conceptual Development Of An Impact-Attenuation System For Intersecting Roadways, Joseph G. Putjenter

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

Longitudinal barriers are commonly used to shield hazards, including stiff bridge rail ends and slopes. In some locations, a secondary roadway intersects the primary roadway within the guardrail’s length-of-need (LON). Some intersections have as little as 15 ft (4.6 m) between the intersection and beginning of the bridge railing, which require short-radius guardrail systems. No short-radius systems have been tested and approved to current impact safety standards for shielding hazards with these conditions.

Site conditions provided by the Nebraska Department of Roads were used to determine the constraints for a new safety treatment for intersecting roadways and include intersection radii, …

Model-Based Condition Monitoring And Power Management For Rechargeable Electrochemical Batteries, Taesic Kim

School of Computing: Dissertations, Theses, and Student Research

Rechargeable multicell batteries have been used in various electrical and electronic systems, e.g., renewable energy systems, electric-drive vehicles, commercial electronics, etc. However, there are still concerns about the reliability and performance degradation of rechargeable batteries caused by low thermal stability and the aging process. A properly designed battery management system (BMS) is required for condition monitoring and control of multicell batteries to ensure their safety, reliability, and optimal performance. The goal of this dissertation research was to develop a novel BMS for rechargeable multicell batteries.

First, this research developed high-fidelity battery models for online condition monitoring and power management of …

Evaluating The Air Emissions From Solid Waste Refuse Trucks, Lauren D. Hauser

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

The air emissions from solid waste refuse trucks is an issue that has not been widely studied, but is becoming an ever increasing issue. In the United States alone they have generated around 251 million tons of waste in 2012. This study in particular will collect data on 24 different refuse trucks (front-load, side-load, and roll-off, and diesel and compressed natural gas fuel) while on real-life routes in the Raleigh, North Carolina area. The collected data will then be aggregated and summarized based on the type of trucks. A regression analysis will also be done to determine the relationship between …

A Finite Element Method Based Microwave Heat Transfer Modeling Of Frozen Multi-Component Foods, Krishnamoorthy Pitchai

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Microwave heating is fast and convenient, but is highly non-uniform. Non-uniform heating in microwave cooking affects not only food quality but also food safety. Most food industries develop microwavable food products based on “cook-and-look” approach. This approach is time-consuming, labor intensive and expensive and may not result in optimal food product design that assures food safety and quality. Design of microwavable food can be realized through a simulation model which describes the physical mechanisms of microwave heating in mathematical expressions. The objective of this study was to develop a microwave heat transfer model to predict spatial and temporal profiles of …

Local Control Robotic Surgical Devices And Related Methods, Eric Markvicka, Tom Frederick, Jack Mondry, Joe Bartels, Shane Farritor

Department of Mechanical and Materials Engineering: Faculty Publications

The various robotic medical devices include robotic devices that are disposed within a body cavity and positioned using a support component disposed through an orifice or opening in the body cavity. Additional embodiments relate to devices having arms coupled to a device body wherein the device has a minimal profile such that the device can be easily inserted through smaller incisions in comparison to other devices without such a small profile. Further embodiments relate to methods of operating the above devices.

Program And Proceedings: Nebraska Academy Of Sciences 1880–2015, 135th Anniversary Year, One Hundred-Twenty-Fifth Annual Meeting

Nebraska Academy of Sciences: Programs and Proceedings

Program

Aeronautics and Space Science

Chemistry and Physics

Collegiate Academy: Biology

Collegiate Academy: Chemistry and Physics

Anthropology

Biological and Medical Sciences

Junior Academy, Senior High Competition

Aeronautics and Space Science, Poster Session

Maiben Memorial Lecture: “Nebraska Biocontainment Unit Planning and Response to Ebola,” Ebola team, University of nebraska medical Center

Applied Science and Technology

Earth Science

Teaching of Science and Math

Junior Academy, Junior High Competition

Monolayer And/Or Few-Layer Graphene On Metal Or Metal-Coated Substrates, Peter Werner Sutter, Eli Anguelova Sutter

Department of Electrical and Computer Engineering: Faculty Publications

Disclosed is monolayer and/or few-layer graphene on metal or metal-coated substrates. Embodiments include graphene mirrors. In an example, a mirror includes a substrate that has a surface exhibiting a curvature operable to focus an incident beam onto a focal plane. A graphene layer conformally adheres to the substrate, and is operable to protect the substrate surface from degradation due to the incident beam and ambient environment.

Department Of Biological Systems Engineering Newsletter, Spring 2015

BSE Department Magazine

No abstract provided.

Should Nuclear Energy Be More Heavily Incorporated By The United States?, Matthew Romer

Nebraska College Preparatory Academy: Senior Capstone Projects

America is involved in one of the biggest races towards electrical efficiency, cleanliness, and productivity. Nuclear energy is a major part of the U.S.’s non-­‐carbon emitting electricity, and has strict regulations for management. However, this form of energy has been on the decline in the past couple decades due to cost and competition with cheaper, less clean methods. Is nuclear energy feasible enough to continue?

Heterogeneity Of Infiltration Rates In Alluvial Floodplains As Measured With A Berm Infiltration Technique, Derek M. Heeren, Garey A. Fox, Daniel E. Storm

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Hydrologic heterogeneities (e.g., macropores and gravel outcrops) in floodplains are hypothesized to play an integral role in impacting flow and leaching between the soil surface and shallow alluvial aquifers, which are intricately connected to streams. Infiltration is often assumed to be uniform, but this neglects the spatial variability common in anisotropic, heterogeneous alluvial floodplain soils. The objective of this research was to quantify infiltration and hydraulic conductivity across a range of scales (point to 100 m²) using a berm infiltration technique. Plot-scale leaching experiments were performed across a range of soil types at each of three floodplain sites …

Engineering Graphene Oxide Membranes For Contaminant Removal And Bacterial Inactivation, Stefan M. Schaepe

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

The need for improved water filtration technologies continues to grow on a global scale. Membrane filtration devices are increasing in use because they can remove a variety of contaminants efficiently. The major issue with membrane filters is biofouling. Coating membranes with nanoparticles such as graphene oxide (GO) can increase contaminant removal and decrease microbial growth.

This research characterizes the properties of the GO itself, two procedures for producing GO coated membranes, the properties of the created membranes and the contaminant removal and bactericidal efficiencies of the membranes. Pure water flux values for GO coated membranes prepared using a direct deposition …

Remote Mobile Screen (Rms): An Approach For Secure Byod Environments, Santiago Manuel Gimenez Ocano

School of Computing: Dissertations, Theses, and Student Research

Bring Your Own Device (BYOD) is a policy where employees use their own personal mobile devices to perform work-related tasks. Enterprises reduce their costs since they do not have to purchase and provide support for the mobile devices. BYOD increases job satisfaction and productivity in the employees, as they can choose which device to use and do not need to carry two or more devices.

However, BYOD policies create an insecure environment, as the corporate network is extended and it becomes harder to protect it from attacks. In this scenario, the corporate information can be leaked, personal and corporate spaces …

Visual Analytics For Large Communication Trace Data, Jieting Wu

School of Computing: Dissertations, Theses, and Student Research

Executions of modern parallel programs often yield complex communications among compute nodes of large-scale clusters of workstations or supercomputers. Analyzing communication patterns is becoming increasingly critical to performance optimiza- tion. As the scale and complexity of parallel applications drastically increases, visu- alization has become a feasible means to conduct analysis of massive communication patterns. However, most visualization tools fall short in showing comprehensive dy- namic communication graph and addressing the scalability issue. Our solution for analyzing dynamic communication patterns is based on an analytics framework cou- pled with a new visualization technique, named CommGram [29], that provides a flexible solution …

Is Aerospace Important To The United States?, Joshua Romer

Nebraska College Preparatory Academy: Senior Capstone Projects

Aerospace is technology and industry in space flight and avia:on. It provides safe and faster means of transporta:on, explora:on, and electronics. Aerospace is responsible for many US exports and improvements. Aerospace is important to research because of its lack of publicity.

Development Of Socketed Foundations For S3x5.7 Posts, Scott K. Rosenbaugh, Tyler L. Schmidt, Ronald K. Faller, John D. Reid

Nebraska Department of Transportation: Research Reports

The objective of this study was to develop a socketed foundation for use with the S3x5.7 (S76x8.5) weak post. The design focused on cylindrical, reinforced concrete foundations with a steel tube placed in the center for use as the socket. The foundation was to prevent both damage and displacements exceeding 1 in. (25 mm), as measured at groundline, during an impact event. To evaluate various foundation designs, ten dynamic bogie tests were conducted over three separate rounds of testing. Round 1 was conducted in a weak, sandy soil; Round 2 was conducted in a strong, stiff soil; and Round 3 …

Safety And Operational Analysis Of Lane Widths In Mid-Block Segments And Intersection Approaches In The Urban Environment In Nebraska, Anuj Sharma, Wei Li, Mo Zhao, Laurence Rilett

Nebraska Department of Transportation: Research Reports

This research examined the safety and operational effects of roadway lane width on mid-block segments between signalized intersections as well as on signalized intersection approaches in the urban environments of Lincoln and Omaha, Nebraska. In the safety analysis, the Poisson and negative binomial regressions with fixed or random parameters were estimated to evaluate the effects of lane width on annual crash frequencies at mid-block segments and intersection approaches. In the operational analysis, linear regressions were used to examine lane width effects on the vehicles’ speed at mid-block segments. The Kolmogorov-Smirnov test was applied to explore the effects of lane width …

Francisella Tularensis Subtype A.Ii Genomic Plasticity In Comparison With Subtype A.I, Marilynn A. Larson, Ufuk Nalbantoglu, Khalid Sayood, Emily B. Zentz, Amanda M. Bartling, Stephen C. Francesconi, Paul D. Fey, Michael P. Dempsey, Steven H. Hinrichs

Department of Electrical and Computer Engineering: Faculty Publications

Although Francisella tularensis is considered a monomorphic intracellular pathogen, molecular genotyping and virulence studies have demonstrated important differences within the tularensis subspecies (type A). To evaluate genetic variation within type A strains, sequencing and assembly of a new subtype A.II genome was achieved for comparison to other completed F. tularensis type A genomes. In contrast with the F. tularensis A.I strains (SCHU S4, FSC198, NE061598, and TI0902), substantial genomic variation was observed between the newly sequenced F. tularensis A.II strain (WY-00W4114) and the only other publically available A.II strain (WY96-3418). Genome differences between WY-00W4114 and WY96- 3418 included three major …