Engineering Commons^™

The Application Of Advanced Composites For The Construction Of Commercial Transport Aircraft, Mark D. Severson

Graduate Student Works

This individual Capstone project examined and evaluated current industry methods of testing, certification, and maintenance of advanced composite materials for the construction of commercial transport aircraft and the FAA regulations governing their use. The project critically compared and contrasted existing FAA standards and regulations governing the testing, certification, and maintenance of advanced composites for commercial transport aircraft structural applications with current industry practices to determine whether there were any areas of conflict between the two in order to accept or reject that current testing, certification, and maintenance procedures for advanced composites used in primary and secondary commercial transport aircraft structures …

International Environmental Design Contest Task: Hyrdaulic Fracturing Fluid Hydrocarbon Removal As A Reverse Osmosis Pretreatment, Elisabeth Yates

Chemical Engineering Undergraduate Honors Theses

Natural gas is useful in several different applications from chemical feed stock, to energy and fuel source. In the past it has been too expensive to be properly taken advantage of, but in recent years technology advancements have made it a rather cheap commodity. However, these advancements, hydraulic fracturing and horizontal drilling, come at an additional cost. They require massive amounts of water, approximately 7,000,000 gallons per well drilled. After use, this water is laden with salts and dangerous hydrocarbons. In order for the water to be recycled or reused, both components must be removed. Reverse osmosis membranes are commonly …

Life-Cycle Assessment Of Nebraska Bridges, George Morcous

Nebraska Department of Transportation: Research Reports

No abstract provided.

Cost-Effective Treatment Of Existing Guardrail Systems, Mitchell J. Wiebelhaus, Karla A. Lechtenberg, Dean L. Sicking, Ronald K. Faller, Scott K. Rosenbaugh

Nebraska Department of Transportation: Research Reports

No abstract provided.

Modeling Of Microbubbles Pushed Through Clots Via Acoustic Radiation Force, E. Carr Everbach, Ascanio Guarini , '16

Engineering Faculty Works

Previous studies have shown that thrombi, which may completely block the blood flow in a vessel, can be dissolved by ultrasound acting on echo-contrast agent microbubbles. The presumed mechanism is acoustic cavitation, the radial oscillations of the bubbles, which can exert locally large forces on the fibrin ropes that make up the clot matrix. However, the movement of the bubbles through the clot in the absence of flow suggests that acoustic radiation force also plays an important role. Because detailed mechanistic modeling of this process is not available, we present here a heuristic study in which microbubble transit times in …

Evolutionary Optimization Algorithms For Nonlinear Systems, Ashish Raj

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the real world, we encounter a number of problems which require iterative methods rather than heuristic approaches to solve them. Not every problem can be solved with a definitive method. Optimization algorithms come to the aid of such instances. These algorithms carry out multiple iterations or generations to try to achieve the lowest value of a cost function. The demand for fast and robust stochastic algorithms to cater to the optimization needs is very high. The faster the convergence to a low value of the cost function, the better the algorithm is. This is attained in greedy criterion approaches, …

Air Vent Sizing In Low-Level Outlet Works For Small- To Medium-Sized Dams, Nathan W. Wright

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The majority of dams contain low-level outlet works, which typically consist of closed conduits that run through the dam, and are used to release water from the reservoir when the water level is below the level of the surface spillways. It is also used to flush the reservoir of sediments and to control the elevation of the reservoir. Low-level outlet works typically consist of a gate that controls the flow within a closed conduit that runs through the dam and an air vent that supplies air behind the gate. In the absence of properly designed air vents, negative pressures may …

Investigation Of Adhesion And Network Properties In Thiol-Ene Polymer Networks Modified With Catechol Functionality For Improved Stone Conservation, Ethan F.T. Hoff

Honors Theses

In this thesis, thiol-ene networks of pentaerythritol allyl ether (APE) and pentaerythritol tris(3-mercaptopropionate) (PETMP) modified with dopamine acrylamide (DAm) containing catechol functionality were formulated and tested in order to investigate the effect the catechol group has on major network properties and adhesion. DAm-APE-PETMP networks were successfully synthesized and applied to a wide variety of substrates (Glass, Steel, Aluminum, etc.) in order to test adhesion. The networks were also characterized using infrared spectroscopy, photo-dynamic scanning calorimetry, dynamic mechanical analysis, and tensile testing. Improved macroscopic adhesion values over the neat APE-PETMP networks were achieved on a variety of substrates including steel, aluminum, …

Expression, Production, And Purification Of Novel Therapeutic Proteins, Mckinzie Shea Fruchtl

Graduate Theses and Dissertations

Interest in the production of recombinant proteins consisting of collagen binding domain (CBD) fused to a bioactive material has increased due to the targeting/attachment capabilities of CBD. For example, CBD fusions can be applied to the reversing of bone density loss and the repair of the eardrum, specifically, by choosing an appropriate fusion partner (parathyroid hormone or epidermal growth factor). The production of CBD fusions was examined using batch and fed-batch culturing of Escherichia coli to express the fusion proteins, and affinity chromatography to isolate the final product.

Different medium formulations, feeding strategies, and induction methods were tested in order …

Synthesis And Characterization Of Iron Pyrite Nanocrystals For Photovoltaic Devices, Scott Curtis Mangham

Graduate Theses and Dissertations

Iron pyrite nanocrystals have been synthesized using a hot-injection method with a variety of amines and characterized with properties necessary for photovoltaic devices. The iron pyrite nanocrystals were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, optical absorption, micro-Raman, and micro-Photoluminescence. The optical absorbance spectra showed the large absorption in the visible and near infrared spectral range for the nanocrystals as well as to show the band gap. The face-centered cubic crystal structure of the iron pyrite nanocrystals was shown by matching the measured X-ray diffraction pattern to a face-centered cubic iron pyrite reference pattern. Using Bragg's law …

A Cradle To Farm Gate Life Cycle Analysis Of Water Use In U.S. Pork Production, Eric Boles

Graduate Theses and Dissertations

The intent of this study was to analyze water use across a range of regions, scales and practices of the U.S. pork industry. A Life Cycle Assessment of water use within the pork supply chain was performed. Cumulative water use was the environmental impact category used in the LCA to evaluate the impacts of pork production processes throughout the pork supply chain. The functional unit for the analysis was the volume of water required to produce one kilogram of swine (live weight) at the farm gate.

A comprehensive literature review was used to design and propagate algorithms for the National …

Analysis Of An Improved Imu-Based Observer For Multirotor Helicopters, John Charles Macdonald, Robert C. Leishman, Randal W. Beard, Timothy W. Mclain

Faculty Publications

Multirotor helicopters are increasingly popular platforms in the robotics community. Making them fully autonomous requires accurate state estimation. We review an improved dynamic model for multirotor helicopters and analyze the observability properties of an estimator based on this model. The model allows better use of IMU data to facilitate accurate state estimates even when updates from a sensor measuring position become less frequent and less accurate. We demonstrate that the position update rate can be cut in half versus typical approaches while maintaining the same accuracy. We also find that velocity estimates are at least twice as accurate no matter …

Preparation And Detection Of Degradation And Chain Scission Events In Epoxy-Amine Networks Using A Profluorescent Nitroxide Probe, Kylee F. Fazende

Honors Theses

Thermosetting polymers comprise a significant part of polymer research that is in progress today because thermosets are especially critical in the field of aerospace composites. In this context the proposed research project is designed to develop a novel method to detect and quantify chain scission and thermal degradation of matrix materials using profluorescent nitroxide probes as well as, to study the interaction of the thermoset with its environment during utilization and property degradation. Acquisition of this knowledge will allow for a better understanding of early, i.e., premacroscopic, thermoset degradation and to establish whether these early events are predictive of material …

Studies On Controlling The Morphology Of An Organic Bulk-Heterojunction Photovoltaic Device To Improve Its Efficiency, Kelly R. Mcleod

Honors Theses

A systematic study of the effects of alteration of processing parameters in combination with incorporation of polyhedral oligomeric silsesquioxane (POSS) molecules on the properties and structure of bulk heterojunction organic photovoltaic cells made from P3HT:PCBM blends was undertaken. On implementing the correct processing protocol, incorporation of POSS molecules with specific structures resulted in considerable enhancement in cell efficiencies. Octaaminophenyl POSS incorporation resulted in a 20% increase in cell efficiency over the control and caused the formation of crystalline, fiber-like structures in the active layer of the photovoltaic cell.

Popularity Of Virtual Reality Immersion In Theme Park Attractions Of North America, Jessica A. Jelinski

Honors Theses

Theme parks continually change to incorporate new technology. Since the development of virtual reality, designers of theme park attractions have utilized several different immersion technology systems. Most of the current attractions are based on the Head-Mounted Display system and the Cave Automatic Virtual Environment system. To date, few studies or papers have been published concerning the effect virtual reality and the accompanying immersion technology may have on theme park attractions. One hundred and seventy-eight attractions from eight theme parks were categorized based on level of immersion and then analyzed for this study. Wait times for these attractions were used to …

Biomass Gasification: An Alternative Solution To Animal Waste Management, Hanjing Wu

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

The overall goal of this research was to evaluate gasification of animal waste as an alternative manure management strategy, from the standpoints of syngas production and biochar application.

To meet the overall objective, the thermogravimetric characteristics of dairy manure, as a thermochemical conversion feedstock, were studied firstly. Then, gasification technology was applied to dairy manure and feedlot manure using a fluidized-bed laboratory-scale gasifier. In addition, biochar derived from the feedlot manure was examined for its effects on nutrient leaching as a soil amendment. Finally, a life cycle assessment was conducted to evaluate greenhouse gas emissions of two feedlot manure management …

Soil Organic Carbon Dynamics In Agriculture: Model Development And Application From Daily To Decadal Timescales, Matthew P. Pelton

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

Soil carbon (C) is the largest terrestrial C pool globally, containing more C than the atmosphere and biosphere. Soil organic carbon (SOC) is a source and sink of CO₂ emissions to and from the atmosphere, thus influencing future climate change. Understanding SOC dynamics is also important for maintaining C stocks to sustain and improve crop yields. An existing model to estimate changes in SOC due to respiration was modified to operate in three computational platforms: MS Excel, MS Excel with Visual Basic for Applications, and supercomputing. This model was validated against CO₂ flux data from a 9-year field …

Predicting Groundwater Trading Participation In The Upper Republican River Natural Resource District, Elizabeth M. Juchems

Department of Agricultural Economics: Dissertations, Theses, and Student Research

The goal of this thesis is to predict participation in groundwater trading and the directions of trades among participants. Specifically, the paper considers both formal and informal trading of groundwater used for crop irrigation purposes and attempts to identify those characteristics that predict the probability of trade participation and whether an individual is a buyer or seller of groundwater rights. While the public benefits from efficient use of groundwater include adequate stream flow in hydrologically connected areas and future use of groundwater supplies, there are significant private benefits to landowners especially in water-short areas. Groundwater trading can help move water …

Molecular Dynamics Simulations Of Plastic Deformation In Dopant-Modified Nanocrystalline Metallic Materials, Lucas Brown

Mechanical Engineering Undergraduate Honors Theses

Polycrystalline metallic materials commonly exhibit the Hall-Petch relationship, which states that decreased grain size leads to increased strength. As a result, nanocrystalline metals, which are defined as polycrystalline metals with average grain diameters on the nanoscale, exhibit ultra-high strength phenomenon. Despite their incredible strength, the applications of these materials are severely limited due to thermodynamic instability that causes low temperature grain growth and a reduction in the enhanced properties. It is known that dopant atoms located at the grain boundaries in nanocrystalline metals can reduce this effect and stabilize the microstructure of these materials, but little is known about the …

Sustainable Urban Rail Trails: Designing The Cross Kirkland Corridor, Mia Cooledge

Scripps Senior Theses

This thesis is a guide to building a sustainable rail-trail, wherein I focus on invasive species removal, green pavement, and creating an inviting space with the inclusion of integrated art. When the City of Kirkland, WA purchased the 5.75 mile long section of railroad going through the city, I approached city manager Kurt Triplett to ask about his plans for the corridor. He liked the idea of aiming for a sustainable trail, so I wrote a guide to building an environmentally friendly trail based on a number of prominent readings on sustainable design.

Energy, U.S. Department Of, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Provides information about the U.S. Department of Energy (DOE) and its predecessor agencies and how DOE influences federal energy policy and scientific research in the western U.S.

Army Corps Of Engineers, U.S., Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Provides an overview of how the U.S. Army Corps of Engineers has influenced historical and contemporary economic, environmental, and political developments in the American West.

Aridity, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Provides an overview of how aridity in the American West has influenced that region's economic, environmental, and political development and U.S. Government policies in this region.

Colorado River Compact (1922), Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Provides an overview of the 1922 Colorado River Compact seeking to fairly distribute Colorado River water to Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming and their increasing populations.

Hydroelectric Power, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Provides a historical overview and contemporary analysis of the advantages and disadvantages of federal government support for hydroelectric power in the American West.

Oil Industry, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Provides an overview of the historical and contemporary development of the American oil industry and how it has impacted U.S. natural resources policies in the American west.

Mining, Uranium, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Provides an overview of uranium mining's role and influence in the American West with comparative information on uranium mining in foreign countries.

Transformable Wheelchair, Benjamin Shurtz

Undergraduate Honors Capstone Projects

This report includes the development, design, and analysis of a transformable wheelchair. There was a need to design and build a wheelchair that transformed to be pushed, pulled, or self-propelled. This design meets the need of physically restricted wheelchair users who frequent simple hiking trails without needing to move to a secondary off-road capable device. Documentation for concepts, analysis, and completed design details follows.

Calibration And Optimization Of A Load Sensor Embedded In A Railroad Bearing Adapter, Lorenzo Saenz Iv

Theses and Dissertations - UTB/UTPA

Freight railcars rely heavily on weigh bridges and stations to determine cargo load. As a consequence, all load measurements are limited to certain locations and specified prices. To this end, this study presents work performed to develop one of the first economical, reliable sensors for keeping track of both dynamic and static loads on a freight railcar. Preliminary testing provided a strain-gauge based sensor that delivered load information in the laboratory environment. Federal Railroad Association (FRA) protocol testing was met and consistent results were obtained from the sensing device. The latter allowed for an optimized sensor that could potentially deliver …

Proper Orthogonal Decomposition Of High-Speed Flows, Oscar Huerta

Theses and Dissertations - UTB/UTPA

In an effort to understand physical characteristics of high speed flows such as an Impinging Jet (Mach 1.5) and Pulsed Jet (Mach 0.3) both propulsions systems are investigated from phased-locked Particle Image Velocimetry (PIV) data that is analyzed using Proper Orthogonal Decomposition (POD). The purpose of POD is to extract the most dominant features found in the flow. The method calculates the eigenvalues and the spatial eigenfunctions that are related to the total kinetic energy with only a few basis functions. Results for an Impinging Jet show about 70% of the energy in the first twenty modes that represent the …