Engineering Commons^™

Evaluation Of Floorpan Tearing And Cable Splices For Cable Barrier Systems, Scott K. Rosenbaugh, Jason A. Hartwell, Robert W. Bielenberg, Ronald K. Faller, James C. Holloway, Karla A. Lechtenberg

Nebraska Department of Transportation: Research Reports

This research effort consisted of two objectives related to components of a prototype cable barrier system. The first objective was to mitigate the potential for vehicle floorpan tearing by modifying the cable guardrail posts. A bogie vehicle was equipped with a simulated floorpan designed to replicate the height, thickness, and strength of the floorpan of a Kia Rio vehicle. Baseline testing demonstrated that the top of the Midwest Weak Post (MWP) would contact, and crease the simulated floorpan, which matched the damage observed in actual full-scale vehicle crash tests. Once the test setup provided the desired results, various post configurations …

Nanostructured Dielectric Materials For High Energy Density Multi Layer Ceramic Capacitors, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

A high energy density multilayer ceramic capacitor, having at least two electrode layers and at least one substantially dense polycrystalline dielectric layer positioned therebetween. The at polycrystalline dielectric layer has an average grain size of less than about 300 nanometers, a particle size distribution of between about 150 nanometers and about 3 micrometers, and a maximum porosity of about 1 percent. The dielectric layer is selected from the group including TiO₂, BaTiO₃, Al₂O₃, ZrO₂, lead zirconium titanate, and combinations thereof and has a breakdown strength of at least about 1100 …

A Handy Underwater Solution, Benjamin Murdoch, Matt Ricks, Ales Ball, Jacob Olson, Ethan Durrant, Connor Monson, Lars Watts, Mark Killpack

Journal of Undergraduate Research

Hod Lipson once asked an audience at TED, “Where are the robots?” We’ve been waiting for them a long time now and modern robotics still hasn’t caught up with our hopes and dreams. Through our research we hope to address one of the major topics in robotics: movement (or kinematics), and use this moment of exploration to build a new low cost robotic hand capable of use within the exciting realm of aquatics.

Thermally Stable Support For Improved Synthetic Fuel Catalysts, Mark Lindsay, Dr. William Hecker, Dr. Morris Argyle

Journal of Undergraduate Research

Fischer-Tropsch Synthesis (FTS) has attracted interest recently as large natural gas deposits have been discovered across the globe. FTS is a gas-to-liquid technology that produces fuels with far fewer sulfur or nitrogen impurities, making it an attractive cleaner alternative to petroleum fuels[1]. Cobalt is the preferred catalyst for FTS[2], but it must be supported to achieve optimal performance. Alumina and silica have been used independently as colbalt FTS supports[3-4], and in mixtures as supports for other processes, but mixed silica-alumina supports have not been studied for FTS applications[5]. The BYU Catalysis Lab has discovered a silica-alumina support (AlSi) with high …

Geogrid-Reinforcement’S Zone Of Influence, Shaun Hilton, W. Spencer Guthrie

Journal of Undergraduate Research

Geogrid is a polypropylene material manufactured with approximately 1-in. wide openings, called apertures. A triaxial geogrid configuration is illustrated in Figure 1. Geogrid reinforcement is typically positioned beneath and/or within an aggregate base layer in a pavement structure and is designed to prevent lateral spreading of the individual aggregate particles comprising that layer. Thus, inter-particle friction can be increased among the individual aggregate particles located above and potentially below the geogrid. When this occurs, the result is an increase in the stiffness of the aggregate base layer that leads to a greater load-carrying capacity of the pavement.

Source Anonymization Of Digital Images: A Counter–Forensic Attack On Prnu Based Source Identification Techniques, Prithviraj Sengupta, Venkata Udaya Sameer, Ruchira Naskar, Ezhil Kalaimannan

Annual ADFSL Conference on Digital Forensics, Security and Law

A lot of photographers and human rights advocates need to hide their identity while sharing their images on the internet. Hence, source–anonymization of digital images has become a critical issue in the present digital age. The current literature contains a number of digital forensic techniques for “source–identification” of digital images, one of the most efficient of them being Photo–Response Non–Uniformity (PRNU) sensor noise pattern based source detection. PRNU noise pattern being unique to every digital camera, such techniques prove to be highly robust way of source–identification. In this paper, we propose a counter–forensic technique to mislead this PRNU sensor noise …

Harnessing Predictive Models For Assisting Network Forensic Investigations Of Dns Tunnels, Irvin Homem, Panagiotis Papapetrou

Annual ADFSL Conference on Digital Forensics, Security and Law

In recent times, DNS tunneling techniques have been used for malicious purposes, however network security mechanisms struggle to detect them. Network forensic analysis has been proven effective, but is slow and effort intensive as Network Forensics Analysis Tools struggle to deal with undocumented or new network tunneling techniques. In this paper, we present a machine learning approach, based on feature subsets of network traffic evidence, to aid forensic analysis through automating the inference of protocols carried within DNS tunneling techniques. We explore four network protocols, namely, HTTP, HTTPS, FTP, and POP3. Three features are extracted from the DNS tunneled traffic: …

An Accidental Discovery Of Iot Botnets And A Method For Investigating Them With A Custom Lua Dissector, Max Gannon, Gary Warner, Arsh Arora

Annual ADFSL Conference on Digital Forensics, Security and Law

This paper presents a case study that occurred while observing peer-to-peer network communications on a botnet monitoring station and shares how tools were developed to discover what ultimately was identified as Mirai and many related IoT DDOS Botnets. The paper explains how researchers developed a customized protocol dissector in Wireshark using the Lua coding language, and how this enabled them to quickly identify new DDOS variants over a five month period of study.

2016 "Meeting Of The Minds" Research Symposium Abstracts

OSRI Journal of Student Research and Innovation

No abstract provided.

Artificial Islands In The South China Sea, Aaron Holmes

OSRI Journal of Student Research and Innovation

The purpose of this study was to understand the value and implications of artificial islands constructed by the People's Republic of China (PRC) in the South China Sea. Qualitative analysis was used with the available literature, sources, and treaties of the topics concerned. The paper concludes that the PRC gains many benefits primarily within the realm of energy security and explores what effects they may

The Face That Launched A Thousand Ships: Helen Of Troy In The Poetry Of Atwood And Tufts, Alea Walstrom

OSRI Journal of Student Research and Innovation

This paper considers the transformation of Greek myth over time, how character’s attributes change over time, and ultimately how contemporary poets employ these myths. The myth of focus in the paper is that of Helen of Troy and the depiction of her character throughout the many years and variations of the myth. Her character is then considered in the contemporary feminist poetry of Carol Tufts and Margaret Atwood.

Low Loss And Low Dispersion Fiber For Transmission Applications In The Terahertz Regime, Sohel Rana, Adnan Siraj Rakin, Harish Subbaraman, Rainer Leonhardt, Derek Abbott

Electrical and Computer Engineering Faculty Publications and Presentations

In this letter we present a novel slotted core fiber incorporating a slotted cladding for the terahertz band. The modal properties of the designed fiber are numerically investigated based on an efficient finite element method (FEM). Simulation results of the fiber exhibit both a low material absorption loss of 0.0103–0.0145 cm^-1 and low dispersion below 0.5 ps/THz/cm within the 0.5–0.9 THz range. Additionally, a number of other features of the fiber have been evaluated.

Sub 2 Nm Particle Characterization In Systems With Aerosol Formation And Growth, Yang Wang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Aerosol science and technology enable continual advances in material synthesis and atmospheric pollutant control. Among these advances, one important frontier is characterizing the initial stages of particle formation by real time measurement of particles below 2 nm in size. Sub 2 nm particles play important roles by acting as seeds for particle growth, ultimately determining the final properties of the generated particles. Tailoring nanoparticle properties requires a thorough understanding and precise control of the particle formation processes, which in turn requires characterizing nanoparticle formation from the initial stages. The knowledge on particle formation in early stages can also be applied …

Pet/Mr Imaging Of Hypoxic Atherosclerotic Plaque Using 64cu-Atsm, Xingyu Nie

McKelvey School of Engineering Graduate Student Theses & Dissertations

ABSTRACT OF THE DISSERTATION

PET/MR Imaging of Hypoxic Atherosclerotic Plaque Using 64Cu-ATSM

by

Xingyu Nie

Doctor of Philosophy in Biomedical Engineering

Washington University in St. Louis, 2017

Professor Pamela K. Woodard, Chair

Professor Suzanne Lapi, Co-Chair

It is important to accurately identify the factors involved in the progression of atherosclerosis because advanced atherosclerotic lesions are prone to rupture, leading to disability or death. Hypoxic areas have been known to be present in human atherosclerotic lesions, and lesion progression is associated with the formation of lipid-loaded macrophages and increased local inflammation which are potential major factors in the formation of vulnerable …

The Effect Of Diffusive Transport On Mineral Carbonation In Geologic Carbon Sequestration, Wei Xiong

McKelvey School of Engineering Graduate Student Theses & Dissertations

Geologic carbon sequestration (GCS) is an effective method to mitigate environmental problems due to excessive anthropogenic CO2 emissions. It involves injecting supercritical CO2 into deep geologic formations in which CO2 will ultimately be converted to solid carbonate minerals. Basalt is a promising host rock that is rich in the divalent cations Ca, Mg and Fe that are important for mineral trapping of CO2. Fractures and pores in basalt reservoirs provide substantial surface area for geochemical reactions during carbon sequestration. The transport in fractures and pores is controlled by diffusion. The coupling of diffusive transport and geochemical reactions leads to carbonate …

Pore Functionalized Pvdf Membranes With In-Situ Synthesized Metal Nanoparticles: Material Characterization, And Toxic Organic Degradation, Hongyi Wan, Nicolas J. Briot, Anthony Saad, Lindell E. Ormsbee, Dibakar Bhattacharyya

Chemical and Materials Engineering Faculty Publications

Functionalized PVDF membrane platforms were developed for environmentally benign in-situ nanostructured Fe/Pd synthesis and remediation of chlorinated organic compounds. To prevent leaching and aggregation, nanoparticle catalysts were integrated into membrane domains functionalized with poly (acrylic acid). Nanoparticles of 16–19 nm were observed inside the membrane pores by using focused ion beam (FIB). This technique prevents mechanical deformation of the membrane, compared to the normal SEM preparation methods, thus providing a clean, smooth surface for nanoparticles characterization. This allowed quantification of nanoparticle properties (size and distribution) versus depth underneath the membrane surface (0–20 μm). The results showed that nanoparticles were uniformly …

Anisotropy And Emission From Air With Laser Filaments, Mohammadamin Rasoulof

Optical Science and Engineering ETDs

Laser filaments are extremely interesting entities for their unique characteristics. The high intensity inside the laser filaments creates nonlinear effects that are useful in many areas of optics. The laser filamentation is an appealing tool in the stand-off spectroscopy for its ability to propagate over long distances while maintains its extreme intensity. However, depletion of energy hinders its propagation over any desired distance. In order to understand the effect of laser filaments on the transparent medium that they propagate through, one needs to investigate interaction of the laser filaments with the constituents of media. In this work we study the …

Underwater Celestial Navigation Using The Polarization Of Light Fields, Samuel Bear Powell

McKelvey School of Engineering Graduate Student Theses & Dissertations

Global-scale underwater navigation presents challenges that modern technology has not solved. Current technologies drift and accumulate errors over time (inertial measurement), are accurate but short-distance (acoustic), or do not sufficiently penetrate the air-water interface (radio and GPS). To address these issues, I have developed a new mode of underwater navigation based on the passive observation of patterns in the polarization of in-water light. These patterns can be used to infer the sun__s relative position, which enables the use of celestial navigation in the underwater environment. I have developed an underwater polarization video camera based on a bio-inspired polarization image sensor …

The Electrophysiology Of Resting State Fmri Networks, Carl David Hacker

McKelvey School of Engineering Graduate Student Theses & Dissertations

Traditional research in neuroscience has studied the topography of specific brain functions largely by presenting stimuli or imposing tasks and measuring evoked brain activity. This paradigm has dominated neuroscience for 50 years. Recently, investigations of brain activity in the resting state, most frequently using functional magnetic resonance imaging (fMRI), have revealed spontaneous correlations within widely distributed brain regions known as resting state networks (RSNs). Variability in RSNs across individuals has found to systematically relate to numerous diseases as well as differences in cognitive performance within specific domains. However, the relationship between spontaneous fMRI activity and the underlying neurophysiology is not …

Characterizing Structure, Properties, And Deformation In Metallic Glasses And Olivine Using Instrumented Nanoindentation, Kelly Kranjc

McKelvey School of Engineering Graduate Student Theses & Dissertations

Micro- and nanomechanical testing can provide significant insight about the structure, properties, and behavior of materials. These techniques are nondestructive, require only limited amounts of material, and have been known to detect a brittle-to-ductile transition in mechanical behavior due to a size effect. This work utilizes this type of testing to explore fundamental questions about the structure, properties, and behavior of two disparate material systems: metallic glasses and olivine.

Metallic glasses are metallic alloys devoid of any long-range order. Their unique atomic structure imbues them with properties such as a high elastic strain limit, near-theoretical strengths, and the ability to …

Development And Applications Of Novel Fluorescent Molecular Probe Strategies, Dolonchampa Maji

McKelvey School of Engineering Graduate Student Theses & Dissertations

Optical imaging and spectroscopy technologies offer the ability to provide structural and functional information in a fast, low-cost, ionizing radiation free, highly sensitive and high throughput fashion. The diverse contrast mechanisms and complementary imaging platforms form the foundation for the application of optical imaging in pre-clinical studies of pathophysiological development as well as direct clinical application as a tool for diagnosis and therapy. Fluorescence imaging techniques have been one of the most rapidly adopted methods in biology and biomedicine. Visualization of biological processes and pathologic conditions at the cellular and tissue levels largely relies on the use of exogenous fluorophores …

Using Pet/Mri To Assess Hepatic Radioembolization Of Yttrium-90 Microspheres, Nichole Millward Maughan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Radioembolization of yttrium-90 (Y-90) microspheres is used to treat primary and secondary cancers in the liver. Though this therapy has existed for decades, the treatment is not well optimized from treatment planning to post-procedural assessment. Recently, there has been a surge to utilize the small positron yield from the radioactive decay of Y-90 for post-radioembolization positron emission tomography (PET) imaging of the microsphere activity distribution. These images provide promise for dosimetry assessment, identifying extrahepatic uptake and possible under-dosed lesions that may benefit from subsequent therapy. However, due to the low positron statistics and high flux of Bremsstrahlung radiation, PET imaging …

Uncertainty Quantification Of Wall-Modeled Large Eddy Simulation (Wmles) Model In Openfoam, Zuoxian Hou

McKelvey School of Engineering Graduate Student Theses & Dissertations

In this thesis, a non-intrusive uncertainty quantification (UQ) method is used to improve the accuracy of a wall-modeled large eddy simulation (WMLES) model. Detailed UQ studies focusing on the closure coefficients of two LES models are performed. A non-intrusive polynomial chaos model is used to evaluate output sensitivities and uncertainties in the entire flow domain. The proposed UQ method allows for the investigation of specific flow features and phenomena within the domain. The results of the UQ analyses are then used to identify which turbulence model closure coefficients most influence the flow features of interest. Sobol indices of closure coefficients …

An Investigation Of Geography And Climate Induced Distresses Patterns On Airfield Pavements At Us Air Force Installations, L K. Sahagun, M Karakouzian, A Paz-Cruz, H De La Fuente Mella

Civil and Environmental Engineering and Construction Faculty Research

This study investigated climate induced distresses patterns on airfield pavements at US Air Force installations. A literature review and surveys of Pavement Condition Index indicated that the predominant factor contributing to the development of pavement distress was climate. Results suggested that, within each type of pavement distress, a geographic pattern exists which is strongly correlated to conventional US climate zones. The US Air Force Roll-Up Database, housing over 50,000 records of pavement distress data, was distilled using a process designed to combine similar distresses while accounting for age and size of samples. The process reduced the data to a format …

Facilitating High Performance Code Parallelization, Maria Abi Saad

Dissertations - ALL

With the surge of social media on one hand and the ease of obtaining information due to cheap sensing devices and open source APIs on the other hand, the amount of data that can be processed is as well vastly increasing. In addition, the world of computing has recently been witnessing a growing shift towards massively parallel distributed systems due to the increasing importance of transforming data into knowledge in today’s data-driven world. At the core of data analysis for all sorts of applications lies pattern matching. Therefore, parallelizing pattern matching algorithms should be made efficient in order to cater …

Improving Distribution And Absorption Of Light In Microalgal Photobioreactors Through Plasmon Enhancement, Entrapped Cultivation And Controlled Motion, Bendy Estime

Dissertations - ALL

Microalgae represent a promising source of renewable biomass for the production of biofuels and valuable chemicals. However, the development of high throughput microalgal cultivation methods and energy efficient biomass harvesting technology is necessary to improve the economic viability of large scale microalgal biomass production.

The issue of poor distribution and absorption of light is one of the hurdle that can be addressed to improve the productivity in microalgal cultivation systems. As it happens, microalgal photosynthetic activities have shown great dependence on the irradiance to which the microalgal cells are exposed. Quantitatively, microalgal growth increases with increasing light intensity until a …

Extraction And Localization Of Noise-Related Flow Structures In High Speed Jets, Pinqing Kan

Dissertations - ALL

The jet noise problem, or the noise radiation from high-speed flow interactions, still remains unresolved after over sixty years of research. With the growing aviation industry, more communities are exposed to noise pollution from aircrafts; and better control strategies are needed to meet the more stringent noise regulations.

This thesis analyzes two sets of high-speed jet flow data and aims at better understanding the flow dynamics and noise radiation mechanism. The first set of data consists of subsonic / transonic axisymmetric jets and the second dataset is of a more advanced configuration: a two-stream supersonic rectangular jet with a flat …

Design And Behavior Of Steel Delta Girders, Omar El Masri

Dissertations - ALL

In steel structures, I-sections are commonly used for beams and columns. These cross-sections usually lack lateral rigidity and torsional stiffness. An effective method to improve their lateral rigidity and overall flexural resistance is to weld two inclined rectangular plates to the compression flange and the compression portion of the web of hot-rolled or welded I-section to form what is known as a Delta girder. This mixed cross-section, i.e., cross-section composed of an open profile attached to a closed profile, can provide enhanced torsional stiffness and hence noticeably higher lateral-torsional buckling (LTB) capacity for the beam. While Delta girders can be …

Combining Smart Material Platforms And New Computational Tools To Investigate Cell Motility Behavior And Control, Megan Brasch

Dissertations - ALL

Cell-extracellular matrix (ECM) interactions play a critical role in regulating important biological phenomena, including morphogenesis, tissue repair, and disease states. In vivo, cells are subjected to various mechanical, chemical, and electrical cues to collectively guide their functionality within a specific microenvironment. To better understand the mechanisms regulating cell adhesive, differentiation, and motility dynamics, researchers have developed in vitro platforms to synthetically mimic native tissue responses. While important information about cell-ECM interactions have been revealed using these systems, a knowledge gap currently exists regarding how cell responses in static environments relate to the dynamic cell-ECM interaction behaviors observed in vivo. Advances …

Experimental And Modeling Study Of Ignition-Resistant Fuels, Apeng Zhou

Dissertations - ALL

This research investigates relative ignition behavior of some oxygenated fuels and their

blends with gasoline surrogates. It seeks to identify fuels with higher resistance to ignition

and validate tentative kinetic models intended to predict their combustion chemistry. It

also develops a method for simplified ignition delay time correlation that can allow for a

more rapid estimation of the ignition behavior of a given fuel at known thermodynamic

conditions.

The work is motivated by the fact that in spark-ignition (SI) engines, increasing energy

conversion efficiency through increasing the engine compression ratio is limited by the

phenomenon of undesired autoignition known as …