Engineering Commons^™

Numerical Modeling Of Submarine Minibasin Flow And Morphodynamics, Elena Bastianon

Theses and Dissertations

Intraslope basins, or minibasins, are important morphological features of the continental slope in both modern and ancient sedimentary systems. Minibasins have an elliptical or spherical shape with a steep inlet or proximal zone followed by an almost horizontal basin floor, and an overflow zone near the downstream basin lip. These basins are filled with sediment transported by successive events of turbidity currents and other types of submarine flows. The work presented here focuses on turbidity current sedimentation in intraslope minibasins, which is often described in terms of the ‘fill-and- spill’ conceptual model. The ‘fill-and-spill’ model has been used previously to …

Exploring Machine Learning Techniques To Improve Peptide Identification, Fawad Kirmani

Theses and Dissertations

The goal of this work is to improve proteotypic peptide prediction with lower pro- cessing time and better efficiency. Proteotypic peptides are the peptides in protein sequence that can be confidently observed by mass-spectrometry based proteomics. One of the widely used method for identifying peptides is tandem mass spectrometry (MS/MS). The peptides that need to be identified are compared with the accurate mass and elution time (AMT) tag database. The AMT tag database helps in reducing the processing time and increases the accuracy of the identified peptides. Prediction of proteotypic peptides has seen a rapid improvement in recent years for …

Characterization Of The Spatial And Temporal Changes In River Geometry And Sand Load With Field Data Analysis And 1d Numerical Modeling, Zeyad Ayoob Sulaiman

Theses and Dissertations

The quantification of the changes in channel geometry and sand load that have occurred on the Missouri River after engineering works and that characterize the Altamaha River in the fluvial-tidal transition zone is the main objective of this research. Dam construction and channelization on the Missouri River resulted in flow regulation, sediment shortage by dam reservoir trapping, channel straightening and narrowing. Quantifying the morphodynamic response of the Lower Missouri River to these engineering projects at short and long-time scales is a difficult problem that we approach with the analysis of the available field data and with the aid of a …

Turning Up Antitumor Immunity Against Breast Cancer, Johnie Hodge

Theses and Dissertations

Breast cancer is the most common cancer in women worldwide, and is the second leading cause of cancer-related death in spite of significant advances in treatment and emphasis on early diagnosis. While treatment of localized disease is often successful, metastatic breast cancer, especially of the triple negative molecular subtype, carries a much poorer prognosis. The significant role of the immune system in the progression from localized to metastatic disease is becoming more and more appreciated. Tumor escape from immune surveillance and immune suppression in the tumor microenvironment have become therapeutic targets in addition to the traditional goals of directly killing …

Topological Conduction And Investigation On Multi Occurrence Of Dirac Cone, Mustahseen Mobashwer Indaleeb

Theses and Dissertations

The unique phenomena in acoustic metamaterial at the Dirac-like cone, and at the exceptional spawning ring could transform the field of engineering with multiple new applications that were never possible before. Localized conical dispersion called Dirac cone at the Brillouin Zone boundaries are the well-known phenomena demonstrated by photonics and phononic metamaterials. However, Dirac cone-like dispersion at the center of the Brillouin zone (where wave number, k = 0) [1] is rare and only happens due to accidental degeneracy at finite frequencies in two-dimensional periodic crystals (PCs), with or without microarchitectures. Accidental degeneracies are generally the ‘sweet spots’ where the …

Ultrasonic Analysis And Tools For Quantitative Material State Awarness Of Engineered Materials, Subir Patra

Theses and Dissertations

The objective of this research is to devise new methods and tools to generate real time awareness of the material state of composite and metallic structures through ultrasonic nondestructive evaluation (NDE) and structural health monitoring (SHM) at its very early stage of failure. To device new methodology it is also important to verify the method through virtual experiments and hence computational NDE is getting popular in the recent years. In this thesis, while experimental methodology is developed to understand the material state at its early stage of failure, a new peridynamic based Peri-Elastodynamic (PED) computational method is also developed for …

Investigation Of The Mechanical Behavior Of Non-Conventional Laminates: Anisotropy Of Tensile Strength In Coupons With Quasi-Isotropic Stiffness Characteristics, Israel Oluwatunmise Ayodele

Theses and Dissertations

Advanced composites have emerged as viable structural solutions over the years and have therefore become implemented in several applications, notably aerospace structures. In modern aircraft structures, they have been gradually introduced to both secondary and primary components. Laminated composites used in such applications have generally been restricted to those with straight fibers, that are aligned to only a handful of pre-selected fiber orientations; 0˚, 45˚, 90˚ and -45˚. Recent advances in the technology of laminated composites have however indicated the possibility to harness significantly higher structural gains by allowing the use of other fiber orientations, and even implementing curvilinear fibers …

Three-Way Catalysts In Passive Selective Catalytic Reduction Systems, Calvin Thomas

Theses and Dissertations

Conventional gasoline-powered engines operate with a stoichiometric air-fuel ratio (AFR), but greater fuel economy is achieved in lean burn engines by increasing the AFR. The primary drawback to these engines is the nitrogen oxide (NOX) emissions, which cannot be reduced over a conventional three-way catalyst (TWC). Passive selective catalytic reduction (SCR) is a promising approach for the control of NOX emissions in lean burn systems. By periodically decreasing the AFR to fuel-rich levels, ammonia (NH3) can be produced over a TWC and stored on a downstream SCR catalyst for the reduction of NOX during normal lean operation. While passive SCR …

Identification Of The Mechanisms Through Which Botanicals Attenuate Pathogenesis Of Human Diseases, Esraah Alharris

Theses and Dissertations

Plant products have been used for a long time in treatment of diseases. In fact, more than half of approved medicines are derived from plants or other natural products. Even though the synthetic drugs are effective in treating many human diseases, there is no cure against several clinical disorders. Moreover, a significant number of diseases can be prevented thereby causing less burden on societal healthcare costs as well as promoting healthy lifestyles. Thus, botanicals offer a unique opportunity to explore novel compounds to prevent and treat various clinical disorders as well as understand their mode of action so that new …

Satellite Constellation Architecture And Design To Take Advantage Of On-Orbit Servicing And Repair, Douglas Sciortino

LMU Theses and Dissertations

Access to space is becoming less expensive, which is allowing smaller companies with big ideas, such as on-orbit servicing and repair, to enter into the space industry. On-orbit servicing and repair provides capabilities, such as towing, refueling, inspections, and physical repair, to add additional life to on-orbit satellites by resolving life-limiting issues. On-orbit servicing and repair is technically possible, but there is still one major issue that continues to stifle the on-orbit servicing and repair market -- “satellites are not built with servicing in mind” (Parker, 2015).

The on-orbit servicing and repair industry is stagnate due to a challenging conundrum. …

The Restoration Of The Nile River And Its Delta, Egypt. Numerical Modeling, Basim Mohammed Naseef Al-Zaidi

Theses and Dissertations

The construction of the High Aswan Dam significantly reduced the flood flows and the sediment supply to the Egyptian portion of the Nile River. Consequences of this changes in river hydrology are diffuse channel bed erosion in the upstream part of the river, in- channel sedimentation in the downstream part of the system, delta recession, habitat deterioration, wetlands loss, water pollution, and environmental problems. The feasibility of a Nile River-Delta restoration project with controlled flow releases and sediment augmentations at Aswan is here investigated with the aid of site-specific one-dimensional morphodynamic models. The water source for the restoration project, based …

Wireless Sensor Networks For Smart Communications, Mu Zhou, Qilian Liang, Hongyi Wu, Weixiao Meng, Kunjie Xu

Electrical & Computer Engineering Faculty Publications

(First paragraph) In the first edition of the special issue titled “Wireless Sensor Networks for Smart Communications”, a total of 22 manuscripts were received and 6 of these were accepted. This issue demonstrated that network congestion, user mobility, and adjacent spectrum interference are the main reasons for the degradation ofcommunication quality inWireless Sensor Networks (WSNs).

Shear Strength Characteristics And Failure Mechanism Of Slopes In Overconsolidated Soils Of Nebraska, Hossein Bahmyari

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

Geotechnical engineers deal with some challenging problems when encountering long-term slope stability in overconsolidated clays and clayey shales. One of these problems is determining a suitable method to estimate the reliable shear strength of overconsolidated clayey soils for long-term slope stability. According to Eversol (2013), one half of the counties in Nebraska have experienced slope failure in overconsolidated soils, especially in north and east Nebraska. In this research, shear strength characteristics of overconsolidated clayey soils of Nebraska is investigated in regard to long-term stability of slopes, and the failure mechanism in such soils is examined.

Undisturbed samples from boring logs …

Study Of The Femtosecond Laser Processed Surfaces, Imprinting, And Casting For Changing The Wettability Of Surfaces, Yingxiao Song

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

Femtosecond Laser Surface Processing (FLSP) is a technology to fabricate micro/nano surface structures. These patterned surface structures show great importance in many applications, especially in controlling the wettability of the surface. Imprinting is a typical method for manufacturing large volumes of surfaces. This study combines two processes (FLSP and stamping) together to produce a surface structure similar to the original FLSP surface. In the first step, micro/nano structured surface mounds were fabricated by femtosecond laser processing. Then, these FLSP surfaces served as molds for subsequent imprinting to replicated the “negative” surface on a blank material. Surface morphology and peak-to-valley roughness …

Group O - Lacrosse Ball Passer, Mackenzie Gordon, Jake Mennemeier, Conor Pellas

Mechanical Engineering Design Project Class

The goal of our design group was to make a lacrosse ball passer that could be used in a team practice or individual setting. Wayne Jaekle, WashU’s head lacrosse coach defined major customer needs as producing a consistent pass speed and angle, an interactive interface allowing an automatic time interval between passes, and being easy to load. These needs lead to our main design goals: 1. A ball capacity of 30, 2. A minimum pass speed of 30 mph, and 3. A 5 second time interval between passes. Mock ups and brainstorming exercises led to our team’s selection of a …

Asme Design Competition - Group H, Melanie Self, Ben Tattersfield, Joshua Emde

Mechanical Engineering Design Project Class

This document presents our solution for the ASME pick-and-place design competition. In brief, the challenge is to collect balls from an arena and return them to a ‘home base’. The specifics of the competition are elaborated on within. The document walks through the design decisions that went into the prototype; the Goalkeeper concept that we ultimately landed on best solved the problems presented by the challenge statement as interpreted by our customer, Dr. James Jackson Potter. Several of the design choices were made by applying mathematical relationships, with the math and results included to illuminate our methods. We include a …

Anisotropic Tissue Maker, Jake Ireland, Jaryd Huffman, Sarah Mohrmann, Daniel Cano

Mechanical Engineering Design Project Class

Traumatic brain injury (TBI) is a common injury that is not thoroughly understood. Data on brain mechanics and motion are not abundant during the time of impact. In order to accumulate more data and achieve a better understanding of how the injury occurs tissue mimics can be made.

T-Shirt Square Cutter, Austin Chawgo, Kendall Weishaar, Samir Lopez

Mechanical Engineering Design Project Class

Each year, Americans waste millions of pounds of textiles in the form of clothing that is thrown away. Professor Mary Ruppert-Stroescu from the Sam Fox School of Design seeks to combat this by reusing the old fabric from discarded clothes and creating new, fashionable clothing. To do this, her and her students cut up donated shirts into small squares, by hand, using scissors and fabric cutters and sew them together using a method developed by her.. This process is very time consuming and limits the commercial viability of this process. The T-shirt Cutter design, detailed below, has the potential to …

Residential Automatic Door Opener, Steven Downs, Ardian Pollo, Ethan Bredemeier

Mechanical Engineering Design Project Class

This project proposes an innovative design for an automatic door opener intended for external doors of residential homes. The intended customers are elderly and disabled people who may benefit from such a device while entering and exiting their homes. The goal is to create an affordable product to compete with existing products that are relatively expensive to make such devices more accessible.

Universal Tube Fixture, Griffin Kivitz, Matthew Whitehill, Jason Hsu

Mechanical Engineering Design Project Class

The goal of this design project was to create a device that can aid in the assembly of glue joints between concentric tubes. In many medical devices, whether they be laser probes, retractable injectors, or other devices with actuating parts, there are often concentric glue joints. The problem we are trying to solve is controlling where the 2 tubes are relative to one another when they are glued.

Lacrosse Ball Passing Machine, William Galik, Daniel Finer, Matt Jenkins

Mechanical Engineering Design Project Class

Design and build a lacrosse ball passing machine that utilizes an automated ball sorting mechanism to shoot balls up to 60 mph with 80 percent accuracy at a 1 square yard target.

Arliss Competition Canister Vehicle, Jessie Goldberg, Nicholas Cornejo, Tyler Smith, Rachel Kershner

Mechanical Engineering Design Project Class

For our project, we designed a canister vehicle that fits the design specifications of the ARLISS competition. For the ARLISS competition, the vehicles are loaded into a rocket, launched approximately 10,000 feet into the air, released, and then must autonomously navigate to a predetermined target on the ground. Because of our time restraint, we are focused on designing a vehicle of the correct dimensions (a maximum mass of 1050g, a maximum diameter of 146mm, and a maximum height of 240mm) that can simply travel on the ground over multiple types of terrain. Additionally, we designed a parachute release mechanism so …

Interpretable Multimodal Retrieval For Fashion Products, Lizi Liao, Xiangnan He, Bo Zhao, Chong-Wah Ngo, Tat-Seng Chua

Research Collection School Of Computing and Information Systems

Deep learning methods have been successfully applied to fashion retrieval. However, the latent meaning of learned feature vectors hinders the explanation of retrieval results and integration of user feedback. Fortunately, there are many online shopping websites organizing fashion items into hierarchical structures based on product taxonomy and domain knowledge. Such structures help to reveal how human perceive the relatedness among fashion products. Nevertheless, incorporating structural knowledge for deep learning remains a challenging problem. This paper presents techniques for organizing and utilizing the fashion hierarchies in deep learning to facilitate the reasoning of search results and user intent. The novelty of …

Electrostatic Design And Conditioning Of A Triple Point Junction Shield For A −200 Kv Dc High Voltage Photogun, G. Palacios-Serrano, F. Hannon, C. Hernandez-Garcia, M. Poelker, H. Baumgart

Electrical & Computer Engineering Faculty Publications

Nuclear physics experiments performed at the Continuous Electron Beam Accelerator Facility (CEBAF) at the Jefferson Lab require a DC high voltage photogun to generate polarized electron beams from GaAs photocathodes. The photogun uses a tapered ceramic insulator that extends into the vacuum chamber and mechanically holds the cathode electrode. Increasing the operating voltage from nominal −130 kV to −200 kV will provide lower beam emittance, better transmission through injector apertures, and improved photocathode lifetime. This desire to increase the photogun operating voltage led to the design of a triple-point-junction shield electrode which minimizes the electric field at the delicate insulator-metal-vacuum …

Simknn: A Scalable Method For In-Memory Knn Search Over Moving Objects In Road Networks, Bin Cao, Chenyu Hou, Suifei Li, Jing Fan, Jianwei Yin, Baihua Zheng, Jie Bao

Research Collection School Of Computing and Information Systems

Nowadays, many location-based applications require the ability of querying k-nearest neighbors over a very large scale of5 moving objects in road networks, e.g., taxi-calling and ride-sharing services. Traditional grid index with equal-sized cells can not adapt6 to the skewed distribution of moving objects in real scenarios. Thus, to obtain the fast querying response time, the grid needs to be split7 into more smaller cells which introduces the side-effect of higher memory cost, i.e., maintaining such a large volume of cells requires a8 much larger memory space at the server side. In this paper, we present SIMkNN, a scalable and in-memory …

Augmenting And Structuring User Queries To Support Efficient Free-Form Code Search, Raphael Sirres, Tegawendé F. Bissyande, Dongsun Kim, David Lo, Jacques Klein, Kisub Kim, Yves Le Traon

Research Collection School Of Computing and Information Systems

Source code terms such as method names and variable types are often different from conceptual words mentioned in a search query. This vocabulary mismatch problem can make code search inefficient. In this paper, we present COde voCABUlary (CoCaBu), an approach to resolving the vocabulary mismatch problem when dealing with free-form code search queries. Our approach leverages common developer questions and the associated expert answers to augment user queries with the relevant, but missing, structural code entities in order to improve the performance of matching relevant code examples within large code repositories. To instantiate this approach, we build GitSearch, a code …

Information Technology System Failure And Value Of Airlines: A Case Study Of Airlines In 2016, Jayendra Gokhale

Publications

Technology is a critical component of a firm’s operations. Technology failures can cause widespread problems in airlines. These failures cause disruptions in flight schedules, cause passengers to be stranded at airports and also increase airline operating costs. The objective of this study is to measure an effect of information technology failures on the firm value of passenger airline companies during the year 2016. In that year, there were cases involving delays and cancellations associated with JetBlue, Southwest, Delta, American, and Virgin America that received significant media coverage. Using the event study methodology, this study finds that the intensity of failures …

Does Length Of Ride, Gender Or Nationality Affect Willingness To Ride In A Driverless Ambulance?, Stephen Rice, Scott R. Winter, Rian Mehta, Joseph R. Keebler, Bradley S. Baugh, Emily C. Anania, Mattie N. Milner

Publications

Due to the frequent lack of ambulances and personnel, the purpose of this study was to examine consumers’ willingness-to-ride in an ambulance that was either driven by a human driver or completely automated (with no human driver) based on the gender of the participant and their nationality, either Indian or American. A two-study experimental design was utilized using over 1,000 participants. In Study 1, the length of the ride and the type of driver were manipulated while in Study 2, the length of the ride was manipulated across genders and nationality. Study 2 also collected affect measures to complete a …

Nanofluidic Applications Of Silica Membranes, John Michael Stout

Theses and Dissertations

This work presents membrane development applicable in nanofluidic devices. These membranes can also be termed suspended thin films, supported on two or more edges. I first discuss motivation and background for developing these structures. Then I derive the formative principles for nanofluidic systems. Following the derivation of the Navier-Stokes and Washburn equations, I discuss applying these theories to planar nanofluidic capillaries and finish the derivation by discussing the forces that drive liquid flow in nanochannels. I next discuss the membrane development process, starting with my work in static height traps, and develop the concept of analyzing nanoparticles using suspended membranes. …

Multispecies Fruit Flower Detection Using A Refined Semantic Segmentation Network, Philipe A. Dias, Amy Tabb, Henry P. Medeiros

Electrical and Computer Engineering Faculty Research and Publications

In fruit production, critical crop management decisions are guided by bloom intensity, i.e., the number of flowers present in an orchard. Despite its importance, bloom intensity is still typically estimated by means of human visual inspection. Existing automated computer vision systems for flower identification are based on hand-engineered techniques that work only under specific conditions and with limited performance. This letter proposes an automated technique for flower identification that is robust to uncontrolled environments and applicable to different flower species. Our method relies on an end-to-end residual convolutional neural network (CNN) that represents the state-of-the-art in semantic segmentation. To enhance …