Engineering Commons^™

The Effect Of A Powered Ankle Foot Orthosis On Walking In A Stroke Subject: A Case Study, Ali Pourghasem, Ismail Ebrahimi Takamjani, Mohammad Taghi Karimi, Mohammad Kamali, Mohammad Jannesari, Iman Salafian

Department of Mechanical and Materials Engineering: Faculty Publications

[Purpose] Standing and walking are impaired in stroke patients. Therefore, assisted devices are required to restore their walking abilities. The ankle foot orthosis with an external powered source is a new type of orthosis. The aim of this study was to evaluate the performance of a powered ankle foot orthosis compared with unpowered orthoses in a stroke patient.

[Subjects and Methods] A single stroke subject participated in this study. The subject was fitted with three types of ankle foot orthosis (powered, posterior leg spring, and carbon ankle foot orthoses). He was asked to walk with and without the three types …

Invasive Species Impacts On Infrastructure, Invasive Species Advisory Committee

National Invasive Species Council

Executive Summary

Invasive species represent one of the most significant threats to ecosystems, human and animal health, infrastructure, the economy, and cultural resources. Because potentially invasive, non-native species typically enter the United States through ports of entry in urban environments, some of the first observable impacts may be to infrastructure, yet little is known about the economic costs associated with these impacts to the “built” environment. In addition, federal agencies currently lack the authority necessary to effectively prevent, eradicate, and control invasive species that impact the human-built environment. This lack of authority prevents rapid response to some of the most …

Self-Patterning Gd Nano-Fibers In Mg-Gd Alloys, Yangxin Li, Jian Wang, Kaiguo Chen, Meiyue Shao, Yao Shen, Li Jin, Guo-Zhen Zhu

Department of Mechanical and Materials Engineering: Faculty Publications

Manipulating the shape and distribution of strengthening units, e.g. particles, fibers, and precipitates, in a bulk metal, has been a widely applied strategy of tailoring their mechanical properties. Here, we report self-assembled patterns of Gd nano-fibers in Mg-Gd alloys for the purpose of improving their strength and deformability. 1-nm Gd nano-fibers, with a 〈c〉-rod shape, are formed and hexagonally patterned in association with Gd segregations along dislocations that nucleated during hot extrusion. Such Gd-fiber patterns are able to regulate the relative activities of slips and twinning, as a result, overcome the inherent limitations in strength and ductility of Mg alloys. …

Modeling Streambank Erosion On Composite Streambanks On A Watershed Scale, A. R. Mittelstet, D. E. Storm, G. A. Fox, P. M. Allen

Biological Systems Engineering: Papers and Publications

Streambanks can be a significant source of sediment and phosphorus to aquatic ecosystems. Although the streambank-erosion routine in the Soil and Water Assessment Tool (SWAT) has improved in recent versions, the recently developed routine in SWAT 2012 has undergone limited testing, and the lack of site or watershed specific streambank data increases the uncertainty in the streambank-erosion predictions. There were two primary objectives of this research: (1) modify and test the 2012 SWAT streambank-erosion routine on composite streambanks, and (2) compare SWAT default and field-measured channel parameters and assess their influence on predicted streambank erosion. Three modifications were made to …

M049 Effects Of Compaction And Soil Moisture On American Burying Beetles, W. Wyatt Hoback

Nebraska Department of Transportation: Research Reports

Silphid beetles in the genus Nicrophorus bury themselves during periods of inactivity, however, the influence of soil characteristics on burial behavior remains unclear. We examined soil preferences of the federally endangered Nicrophorus americanus, as well as of N. carolinus, N. marginatus, N. obscurus, and N. orbicollis, in a series of experiments. Differences in burial depth by sex were found for N. carolinus, N. marginatus, and N. obscurus, which are diurnal species. Both sexes of N. americanus bury to a mean depth of 18 cm. Soil preferences tested included sand versus sandy loam versus sandy loess, degrees of soil moisture, and …

A New System For Human Microrna Functional Evaluation And Network, Jiachun Han

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

MicroRNAs are functionally important endogenous non-coding RNAs that silence host genes in animal and plant via destabilizing the mRNAs or preventing the translation. Given the far-reaching implication of microRNA regulation in human health, novel bioinformatics tools are desired to facilitate the mechanistic understanding of microRNA mediated gene regulation, their roles in biological processes, and the functional relevance among microRNAs. However, most state-of-the-art computational methods still focus on the functional study of microRNA targets and there is no e ective strategy to infer the functional similarity among microRNAs. In this study, we developed a new method to quantitatively measure the functional …

Evaluation Of Dowel Bar Inserter Practices In Pcc Pavements With Magnetic Tomography Technology, Farshad Fallah, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

Dowel Bar Inserters (DBI) are automated mechanical equipment that position dowel bars in Portland Cement Concrete (PCC) after concrete is placed. Compared to the alternative approach, which is using dowel baskets, DBIs offer advantages in cost and speed of construction. However, as dowel bars are not anchored to the subgrade similar to dowel baskets, there is a concern about the quality of dowel placement using this equipment. Improper placement of dowel bars can lead to reduced load transfer between slabs, which results in pavement distresses such as faulting and spalling at joints. To determine the accuracy of dowel placement by …

Continuous Long-Term Health Monitoring Using Ultrasonic Wave Propagation, Ece Erdogmus

Nebraska Department of Transportation: Research Reports

No abstract provided.

Effectiveness Study Of Unl’S Crack Routing Device (Crd) –Phase Ii, Changbum Ahn, Yong Cho, Hamed N. Rafsanjani, Heath Wiley

Nebraska Department of Transportation: Research Reports

This project evaluated the crack routing device (CRD) for effectiveness in improving current crack-cutting practices and for possible adoption as a standard in the Nebraska Department of Roads (NDOR). To enact these evaluations of CRD, the research team collaborated with NDOR to conduct surveys and field tests. Given the positive results obtained from this project, improved road-maintenance practices are anticipated when CRD is used, and this research therefore recommends the adoption of CRD in crack-routing work.

Deployment And Evaluation Of An Active Rfid Tracking System For Precision Animal Management, Brian Barnes

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

A better understanding of animal space utilization in current livestock facilities could lead to improved facility design and animal health. This study was conducted to determine whether an active RFID tag tracking system could accurately provide animal locomotion data on an individual animal basis. The system is composed of four sensors, located in the corners of a swine pen, and compact tags, which attach to the animals and transmit a signal. The sensors use the tag signals to determine 3-D positions in real-time. A data acquisition system was developed to capture raw data from the system software into a database …

Photoluminescence Studies Of Amorphous Boron Carbide And Tungsten Diselenide Thin Films, David M. Allendorfer

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

For many years scientists and engineers have been researching semi-conducting materials for use in a broad array of electronic devices. With the growing demand for faster, smaller and more efficient electronics, new materials must be characterized and their properties quantified. The focus of this thesis is to develop a system to measure photoluminescence in opto-electronic materials. Photoluminescence measurements are important because it can give researchers valuable information about a material’s band structure. This thesis begins by presenting the carrier recombination mechanisms and how they apply to photoluminescence. A system was developed to measure photoluminescence spectroscopy. This system was tested with …

Condition Factor Calibration For Load And Resistance Factor Rating Of Steel Girder Bridges, Pranav M. Shakya

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

The Load and Resistance Factor Rating (LRFR) is a reliability-based rating procedure complementary to the Load and Resistance Factor Design (LRFD). The intent of LRFR is to provide consistent reliability for all bridges regardless of in-situ condition. The primary difference between design and rating is the uncertain severity and location of deterioration, including the potential future loss of strength for an element already evidencing deterioration. Ostensibly, these uncertainties are accounted for by applying an additional strength reduction factor: the condition factor, ϕ_c. Currently, condition factors are nominally correlated to the condition of the member, which can be Good, …

The Effect Of Frequency Resolution On Intelligibility Sentence And Its Relevance To Cochlear Implant Design, Seth H. Roy

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

The purpose of this study is to understand how electrical stimulation (as opposed to acoustical stimulation) of the auditory nerve is used in cochlear implants. Speech is a complex signal that changes rapidly in time and frequency domains. Since phonemes (the smallest unit of speech that distinguishes words) depend on nuanced differences in frequency patterns, it would be expected that a signal with drastically reduced frequency information would be of limited value for conveying speech. Such a frequency-poor signal is the object to be investigated in the present work. It is also the basis of the way speech is represented …

Vector Magneto-Optical Generalized Ellipsometry For Determining Magneto-Optical Properties Of Thin Films, Chad Briley

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

Modern growth techniques allow for highly complex nano scale thin films to be created. These new films possess highly anisotropic properties structurally, optically, and magnetically that are significantly different from that of their bulk counterparts and must be accurately characterized in order to optimize desired properties for applications in next generation devices. Current magnetometry techniques focus on high symmetry characterization, namely in and out of the sample plane, and therefore do not possess the capabilities to fully explore these anisotropic properties without complicated setups and multiple sample manipulations. The author describes a setup that combines generalized ellipsometry with an octu-pole …

A Generic Benchmark For A Mini-Split Heat Pump System, Yuchen Wang

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

Heating, Ventilation, and Air Conditioning (HVAC) accounts for half of the building energy consumption in the U.S where Mini-Split Heat Pumps (MSHPs) are an emerging type of HVAC system. Their utilization has greatly increased by 34% from 2009 to 2013 and high potential EER is recognized for MSHPs. However, there is limited research involving MSHPs systems, and there is no generic benchmark for system testing and modeling. The available simulation tools such as VapCyc, GreatLab, and CYCLE_D are either too complicated, difficult to access, or not freely available. Therefore, an accurate and public share generic benchmark is essential and will …

Design And Implementation Of Reconfigurable Patch Antennas For Wireless Communications, Fei He

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

Reconfigurable patch antennas have drawn a lot of research interest for future wireless communication systems due to their ability to adapt to changes of environmental conditions or system requirements. The features of reconfigurable patch antennas, such as enhanced bandwidths, operating frequencies, polarizations, radiation patterns, etc., enables accommodation of multiple wireless services.

The major objective of this study was to design, fabricate and test two kinds of novel reconfigurable antennas: a dual-frequency antenna array with multiple pattern reconfigurabilities, and a pattern and frequency reconfigurable Yagi-Uda patch antenna. Comprehensive parametric studies were carried out to determine how to design these proposed patch …

Characterization Of Ground Nozzles For Pesticide Applications, Ryan Henry

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Pesticide applications are a common component of crop production systems in the United States (US). For row crop systems (e.g. corn, soybean, or wheat), pesticides are applied by ground, aerial, or chemigation methods. The exact method of pesticide delivery is not universally regulated/ prescribed in the US, and the equipment and application technique are largely defined by the individual applicator. A wide variety of choices and decisions must be made by applicators to result in a successful pesticide application. Examples of these choices include proper active ingredient(s), carrier volume and equipment (e.g. nozzle type, spacing, and operating pressure) selection while …

Microstructure And Properties Of Spark Plasma Sintered Moalb Ceramics, Ting Lou

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

Molybdenum aluminum boride (MoAlB) is a ternary transition metal boride which has promising aeronautic and nuclear applications. It inheres excellent properties of the binary transitional metal borides (e.g., MoB, ZrB₂) such as high melting temperature, high hardness, and thermal conductivity. Besides, MoAlB is superior to MoB because: (1) the Al element provides an oxidation resistance at high temperatures; (2) its nanolaminated structure consisting of M-B layers with alternating Al layers results in a unique damage tolerance property. In this research, polycrystalline MoAlB have been successfully synthesized and simultaneously sintered using spark plasma sintering (SPS) from molybdenum boride (MoB) …

Optimal Grading For Strength And Functionality Of Parts Made Of Interpenetrating Polymer Networks: Load Capacity Enhancement, Zhong Chen

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

Uniform parts with stress concentrations or singularities are prone to failure under relatively small loads, which motivates researchers to seek methods to enhance the strength of these parts. This dissertation studies the optimization of material grading to design parts made of functionally graded interpenetrating polymer networks (FG-IPNs) to improve their load capacity.

An acrylate/epoxy IPN with variations of elastic Young’s modulus, Poisson’s ratio, and ultimate stress at failure is used for optimization of a plate with stress concentration. The grading is optimized by attaching the finite element method (FEM) solver to a general purpose bound-constrained optimizer. Two examples, a plate …

Design Of A Flexible Control Platform And Miniature In Vivo Robots For Laparo-Endoscopic Single-Site Surgeries, Lou P. Cubrich

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

Minimally-invasive laparoscopic procedures have proven efficacy for a wide range of surgical procedures as well as benefits such as reducing scarring, infection, recovery time, and post-operative pain. While the procedures have many advantages, there are significant shortcomings such as limited instrument motion and reduced dexterity. In recent years, robotic surgical technology has overcome some of these limitations and has become an effective tool for many types of surgeries. These robotic platforms typically have an increased workspace, greater dexterity, improved ergonomics, and finer control than traditional laparoscopic methods. This thesis presents the designs of both a four degree-of-freedom (DOF) and 5-DOF …

Models For Decanting Gaseous Fuel Tanks: Simulations With Gfssp Thermal Model, Kailash Kumar Jain Munoth

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

Transport of fuel from distillation/storage plant to different parts of the world has always been challenging task for Engineers. Different methods have been proposed over the time for transporting fuel efficiently and at low cost which include Marine vessels, Pipelines, Rail Cars and Trucks. In order to transport useful amount of fuel in a reasonably sized tank, we have to liquefy it. While few fuels are easy to liquefy there are great number of fuels which liquefy only under extreme pressure/temperature conditions. Methane has a boiling point of -161.7°C at atmospheric pressure which means it has to be cooled to …

Design And Evaluation Of Pediatric Gait Rehabilitation Robots, Cale J. Stolle

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

Gait therapy methodologies were studied and analyzed for their potential for pediatric patients. Using data from heel, metatarsal, and toe trajectories, a nominal gait trajectory was determined using Fourier transforms for each foot point. These average trajectories were used as a basis of evaluating each gait therapy mechanism. An existing gait therapy device (called ICARE) previously designed by researchers, including engineers at the University of Nebraska-Lincoln, was redesigned to accommodate pediatric patients. Unlike many existing designs, the pediatric ICARE did not over- or under-constrain the patient’s leg, allowing for repeated, comfortable, easily-adjusted gait motions. This design was assessed under clinical …

Dynamic Responses Of Wheel-Rail Systems With Block Dampers, Tzuyu Tseng

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

The wheel-rail interaction problem has been widely studied in the past few decades. In this problem, dynamic responses at the contact areas remain the central issue since they induce damage to the rail over time. In particular, the dynamic responses at the contact areas between the wheels and rails present difficulties in understanding and mathematical modeling. Even with the computer power one has today, its mathematical modeling employs the versatile numerical analysis method, the finite element method (FEM) remains a formidable challenge due to its extremely small contact areas and in turn the extremely high stress levels. In addition, friction …

Spatial Distribution Of Antibiotic Resistance In Soils Receiving Beef Feedlot Runoff, Scott Speicher

Department of Environmental Engineering: Theses and Student Research

A study was conducted to provide new insight on the potential contribution to antibiotic resistance from the land application of beef feedlot runoff to soil. This study reports the distribution and quantity of antibiotic resistant bacteria (ARBs), fecal indicator bacteria (FIB), and antibiotic resistance genes (ARGs) in soil from (i) a field receiving long-term application of beef feedlot runoff holding pond effluent and (ii) a cool-season pasture with no history of supplemental manure application.

Soil samples were collected June 2015 at the U.S. Meat Animal Research Center near Clay Center, Nebraska. A response surface sampling design (RSSD) model based on …

Investigation Of Subjective Perception & Objective Metrics Of Acoustic Room Diffusion, Jay Michael Bliefnick

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

While a variety of assessment methodologies have been proposed to quantify acoustic diffusivity within rooms, a link between these and the perception of diffusion has not been fully established. This study investigated various ways of analyzing diffusion, through both human perception and objective metrics. Numerous impulse response measurements were collected from a physical acoustics testing facility designed for diffusion research. This space featured reversible absorptive/diffusive/reflective wall panels, which allowed numerous testing configurations. One such setup investigated how changing the diffusivity of an isolated wall surface impacted diffusive room conditions. Alternatively, the effects diffuser configurations had on diffusive room conditions were …

On Path Consistency For Binary Constraint Satisfaction Problems, Christopher G. Reeson

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

Constraint satisfaction problems (CSPs) provide a flexible and powerful framework for modeling and solving many decision problems of practical importance. Consistency properties and the algorithms for enforcing them on a problem instance are at the heart of Constraint Processing and best distinguish this area from other areas concerned with the same combinatorial problems. In this thesis, we study path consistency (PC) and investigate several algorithms for enforcing it on binary finite CSPs. We also study algorithms for enforcing consistency properties that are related to PC but are stronger or weaker than PC.

We identify and correct errors in the literature …

Optimization Of Irrigation Decision In Cornsoywater, Dharmic Payyala

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

A crop simulation model is used to estimate crop production as a function of weather conditions, soil parameters, and plant related inputs. These crop simulation models are extensively used by farmers, corporations and policy makers for agronomical planning and decision making. CornSoyWater is one such application which provides irrigation recommendation for soy and corn farmers using hybrid maize and soy sim models. As this is a simulation technology, the accuracy of results depends on the quality of data provided to it. One such important input parameter is weather data. CornSoyWater simulates field and crop conditions by retrieving the updated weather …

Characterization Of Molecular Communication Based On Cell Metabolism Through Mutual Information And Flux Balance Analysis, Zahmeeth Sayed Sakkaff

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

Synthetic biology is providing novel tools to engineer cells and access the basis of their molecular information processing, including their communication channels based on chemical reactions and molecule exchange. Molecular communication is a discipline in communication engineering that studies these types of communications and ways to exploit them for novel purposes, such as the development of ubiquitous and heterogeneous communication networks to interconnect biological cells with nano and biotechnology-enabled devices, i.e., the Internet of Bio-Nano Things. One major problem in realizing these goals stands in the development of reliable techniques to control the engineered cells and their behavior from the …

Semeo: A Semantic Equivalence Analysis Framework For Obfuscated Android Applications, Zhen Hu

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

Software repackaging is a common approach for creating malware. In this approach, malware authors inject malicious payloads into legitimate applications; then, to ren- der security analysis more difficult, they obfuscate most or all of the code. This forces analysts to spend a large amount of effort filtering out benign obfuscated methods in order to locate potentially malicious methods for further analysis. If an effective mechanism for filtering out benign obfuscated methods were available, the number of methods that must be analyzed could be reduced, allowing analysts to be more productive. In this thesis, we introduce SEMEO, a highly effective and …

Autonomous Uavs For Near Earth Environmental Sensing, David J. Anthony

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

Unmanned aerial vehicles (UAVs) are playing an increasing role in large scale environmental monitoring. Small UAVs are increasingly used to monitor agricultural fields, infrastructure projects, and disaster areas. The combination of their sensors, ease of use, and portability make them an ideal tool for collecting information on demand about geographic regions. These small UAVs do have several significant limitations. The UAVs have very limited autonomy and fly pre-determined flight paths far above the underlying terrain, limiting the spatial resolution of the collected data. Current battery technology severely limits their flight times, which in turn limits the temporal resolution of the …