Engineering Commons^™

Computational Simulation Of The Paw-04 Nozzle Configuration, Juan Hernandez

Honors Theses

The research was based on the 4th Propulsion Aerodynamics Workshop which was organized by the American Institute of Aeronautics and Astronautics (AIAA) Air Breathing Propulsion System Integration Technical Committee and its objective was to assess the accuracy and numerical prediction capabilities of Computational Fluid Dynamics (CFD). It focused on the work of Behrouzi and McGuirk where they tested two different nozzle configurations under set boundary conditions. The nozzle configurations included a high aspect ratio rectangular nozzle with a clean exit and the same nozzle with an aft-deck attached to the exit. Three different unstructured grids were generated for the clean …

The Effect Of Soil Saturation On The Heat Transfer Rate In A Controlled Environment For Application To Ground Source Heat Pumps, William Barnard

Honors Theses

With the worldwide push for environmentally friendly technology, the topic of geothermal systems has only become more important. Ground Source Heat Pumps (GSHPs) are heat pumps that take advantage of the natural temperature difference between the soil and the air to decrease the amount of power necessary to heat an area. A GSHP has been shown to be capable of increasing efficiency by 3 or 4 times the amount of a conventional heating and cooling system [4]. To take advantage of the full capabilities of a GSHP, one needs to understand what factors can increase or decrease efficiency. While research …

Universal Bike Suspension Design, Ernesto Huerta, Gregory Ryan Ritter, Chris Michael Fedor, Michael Wu

Mechanical Engineering

Cal Poly Bike Builders (CPBB) is a student club at Cal Poly helping students design and fabricate their own bicycles. Currently, club members build rigid frames and mountain bikes with only front-suspension–commonly referred to as a “hardtail”. As more students join the club, interest grows in building full-suspension mountain bikes (FSMTB). Designing and manufacturing a mountain bike rear-suspension system requires a diverse skillset and a substantial time commitment. As a result, individual efforts building FSMTB have proven unsuccessful. The scope of this project is to develop a defined method and necessary tools such that all CPBB members can efficiently build …

Classification Of The 4 Stages Of Diabetic Retinopathy Using A Low Complexity Convolutional Neural Network., Zeliha Ogur

Electronic Theses and Dissertations

Diabetic Retinopathy is an eye disease that affects the blood vessels of the retina tissue found in the back of the eye. The blood vessels in the retina discharge fluid or cause hemorrhage when affected by diabetic retinopathy. It leads to loss of eye vision with people with diabetics and also among working adults. The disease may advance in four stages which include Mild nonproliferative, moderate nonproliferative, severe nonproliferative and proliferative diabetic retinopathy. In the mild stage also known as background retinopathy, lumps occur in the blood vessel and distort a little amount of blood. At this stage, you are …

Maximizing Space Utilization In Unit-Load Warehouses., Luis Felipe Cardona Olarte

Electronic Theses and Dissertations

In a unit-load warehouse, products are stored and retrieved in pallet quantities. Examples include retail distribution centers (DC), third-party DCs, and transshipment hubs in freight transportation. Expenses related to space are a significant component of the operational cost of unit-load warehouses; therefore, maximizing space utilization is important. Moreover, the continuing revolution of retail e-commerce is changing the role and design of modern distribution centers (Boysen et al., 2018). An important trend with serious implications for design is the desire of many distributors to locate DCs in or near metropolitan areas in order to support same-day service or better (Thuermer, 2018). …

Modeling And Counteracting Exposure Bias In Recommender Systems., Sami Khenissi

Electronic Theses and Dissertations

Recommender systems are becoming widely used in everyday life. They use machine learning algorithms which learn to predict our preferences and thus influence our choices among a staggering array of options online, such as movies, books, products, and even news articles. Thus what we discover and see online, and consequently our opinions and decisions, are becoming increasingly affected by automated predictions made by learning machines. Similarly, the predictive accuracy of these learning machines heavily depends on the feedback data, such as ratings and clicks, that we provide them. This mutual influence can lead to closed-loop interactions that may cause unknown …

A Study On Ultrasonic Energy Assisted Metal Processing : Its Correeltion With Microstructure And Properties, And Its Application To Additive Manufacturing., Anagh Deshpande

Electronic Theses and Dissertations

Additive manufacturing or 3d printing is the process of constructing a 3-dimensional object layer-by-layer. This additive approach to manufacturing has enabled fabrication of complex components directly from a computer model (or a CAD model). The process has now matured from its earlier version of being a rapid prototyping tool to a technology that can fabricate service-ready components. Development of low-cost polymer additive manufacturing printers enabled by open source Fused Deposition Modeling (FDM) printers and printers of other technologies like SLA and binder jetting has made polymer additive manufacturing accessible and affordable. But the metal additive manufacturing technologies are still expensive …

A Two-Stage Approach To Ridesharing Assignment And Auction In A Crowdsourcing Collaborative Transportation Platform., Peiyu Luo

Electronic Theses and Dissertations

Collaborative transportation platforms have emerged as an innovative way for firms and individuals to meet their transportation needs through using services from external profit-seeking drivers. A number of collaborative transportation platforms (such as Uber, Lyft, and MyDHL) arise to facilitate such delivery requests in recent years. A particular collaborative transportation platform usually provides a two sided marketplace with one set of members (service seekers or passengers) posting tasks, and the another set of members (service providers or drivers) accepting on these tasks and providing services. As the collaborative transportation platform attracts more service seekers and providers, the number of open …

Secondary Resonances Of Electrostatically Actuated Mems Cantilevers, Christopher I. Reyes

Theses and Dissertations

In this work the behavior of micro-electromechanical (MEMS) cantilever resonators is investigated. The cantilever resonators are electrostatically actuated with hard AC voltage resulting in nine distinct resonances cases including super and subharmonic resonances. The amplitude frequency and amplitude voltage bifurcation diagrams are obtained for each of the nine resonance cases. Reduced order models (ROMs) are developed to include one and two modes of vibration. Three different methods are used to solve the ROMs namely 1) the method of multiple scales (MMS), which is a perturbation method used for one mode of vibration, 2) the homotopy analysis method (HAM), which is …

A Microfluidic Platform For The Simultaneous Quantification Of Methanogen Populations In Anaerobic Digestion Processes, Prince Peter Mathai, Hannah M. Dunn, Kaushik Venkiteshwaran, Daniel Zitomer, James Maki, Satoshi Ishii, Michael J. Sadowsky

Civil and Environmental Engineering Faculty Research and Publications

Methanogens are a diverse group of archaea that play a critical role in the global carbon cycle. The lack of appropriate molecular tools to simultaneously quantify numerous methanogenic taxa, however, has largely limited our ability to study these communities in a wide variety of habitats, such as anaerobic digesters (ADs). In this study, 34 probe-based quantitative PCR (qPCR) assays were designed to target all known methanogenic genera within the archaeal phylum Euryarchaeota. These qPCR assays were adapted to a high-throughput microfluidic platform, which allowed for the simultaneous detection and absolute quantification of numerous taxa in a single run. The …

Methods Utilizing The Phenomena Of Light Scattering To Measure Microscopic Aluminum Oxide Particle Size In Both Solution And Turbulent Air Flow, Lawrence Edward Deese

Honors Theses

Lawrence Deese: Methods Utilizing the Phenomena of Light Scattering to Measure Microscopic Aluminum Oxide Particle Size in Both Solution and Turbulent Air Flow The purpose of this research project was to measure microscopic aluminum oxide (alumina) particle size both in solution and in air flow. Experimentally, the process of sizing microscopic particles is technically challenging. Two methods were used for measuring the sizes of 4 different manufacturer labeled aluminum oxide particles sizes. The first method was using Dynamic Light Scattering analyzed by a LS Spectrometer to measure the alumina particle size while suspended in solution. The second method was using …

The Chevron Bunionectomy For Moderate To Severe Deformity: Effects Of Varying Procedural Factors In Hallux Valgus Correction, Hunter Reed Harrison

Honors Theses

With growing popularity of minimally invasive surgery, the Chevron bunionectomy has been investigated for use in moderate to severe hallux valgus. This study investigates procedural components of lateral release, fixation, and 2nd digit procedures to evaluate effects on outcome. 109 out of 325 patients of a distal Chevron osteotomy with a minimum preoperative IMA of 15° completed the phone survey rating satisfaction and pain levels. Patients were contacted an average of 5.2 years postoperatively. 83% of patients reported being extremely to very satisfied with their outcome. Only 9 patients complained of current foot pain greater than or equal to 5 …

Using Transfer Learning In Network Markets, Kai Cai

Dissertations, Theses, and Capstone Projects

Mechanism design is the sub-field of microeconomics and game theory, which considers agents have their own private information and are self-interested and tries to design systems that can produce desirable outcomes. In recent years, with the development of internet and electronic markets, mechanism design has become an important research field in computer science. This work has largely focused on single markets. In the real world, individual markets tend to connect to other markets and form a big “network market”, where each market occupies a node in the network and connections between markets reflect constraints on traders in the markets. So, …

Fashion Merchandising: An Augmented Reality, Naeha A. Sayed

Dissertations, Theses, and Capstone Projects

There is a continuous and constant transformation in the field of Augmented Reality (AR), both in the Retail, and the Manufacturing sector. It has started to influence everything from fashion runway shows to online shopping. Consumers dynamics have shifted in the fashion industry, the ways becoming more dominant than the old observant ones- the simple buying experience no longer satisfies them. Due to the emergence of the new digital platforms and technological enhancements, the consumers are looking for more- be it a more exciting buying experience or more user interaction or more enhanced products. This technological change starts with the …

Design Of Two-Stage Operational Amplifier Using Indirect Feedback Frequency Compensation, Roderick Gomez

Electrical Engineering Undergraduate Honors Theses

This thesis work details the designing process of two silicon two-stage operational amplifiers with indirect feedback compensation and with Miller compensation technique. The main objective of this thesis is to study the advantages of indirect feedback compensation in comparison with Miller compensation and how this technique can be applied to meet certain design specifications. The operational amplifiers are designed with 130 nm Silicon Germanium CMOS process ideally for temperature range of 25°C to 300°C. The two op-amps are designed to have a DC gain of about 70 dB and 60 degrees of phase margin. The indirect feedback compensation design showed …

Designing, Simulating, And Layout Of An Rfic Mixer In A 130 Nm Sige Process, Logan Walz

Electrical Engineering Undergraduate Honors Theses

Wireless devices are becoming increasingly popular each day ranging from smartphones to Amazon Echo’s to wireless sensors in industry. While all of these devices are quite different in their functions and purposes, they all rely on wireless communication heavily and signal modulation techniques. One component typically seen in wireless applications like this are mixers, which are used to modulate the signal being sent and received. This thesis details the design, simulation, and layout of a radio frequency integrated circuit mixer in a 130 nanometer silicon germanium process. While the fabricated mixer did not perform to standards, many things were learned …

Optical Response Analysis Of Thz Photoconductive Antenna Using Comsol Multiphysics, Jose Isaac Santos Batista

Electrical Engineering Undergraduate Honors Theses

A THz photoconductive antenna consists of antenna pads laid over a photoconductive substrate. These types of antennas are excited through the application of an optical pump (laser), which generates carriers inside the semiconductor. The acceleration and recombination of these carriers produce photocurrent that excites the antenna and generates THz pulse. This thesis focuses on analyzing the optical response of a photoconductive antenna, which consist of the interaction of the incident electric field of a laser pump with the radiating device. It develops the amplitude modulation process of a plane wave of light into a laser pump. It also takes into …

Characterization Of High Temperature Optocoupler For Power Electronic Systems, David Gonzalez

Electrical Engineering Undergraduate Honors Theses

High-temperature devices have been rapidly increas due to the implementation of new technologies like silicon carbide, high-temperature ceramic, and others. Functionality under elevated temperatures can reduce signal integrity reducing the reliability of power electronic systems. This study presents an ongoing research effort to develop a high-temperature package for optocouplers to operate at higher temperature compared with commercial devices. Low temperature co-fired ceramic (LTCC) was used as the substrate. Bare die commercial LED and photodetectors were attached to the substrate and tested for functionality. Preliminary results show enhanced performance at elevated temperatures compared to a commercial optocoupler device.

Synthesis And Characterization Of Dielectric And Multiferroic Nanocrystalline Transition Metal Oxide Materials And Nanocomposites, Frederick A. Pearsall

Dissertations, Theses, and Capstone Projects

Nanocrystalline transition metal oxides with unique chemical, physical, magnetic and dielectric properties have very broad applications, ranging from photocatalysis, capacitor energy storage and 4-state memory. Frequency stable, high permittivity nanocomposite capacitors produced under mild processing conditions offer an attractive replacement to MLCCs derived from conventional ceramic firing. In one project reported herein, 0-3 nanocomposites were prepared using BaTiO₃ (barium titanate, BTO) nanocrystals, suspended in a poly(furfuryl alcohol) matrix, resulting in a stable, high effective permittivity, low and stable loss dielectric. Effective medium approximations were used to compare this with similar nanocomposite systems. The use of synthesized BTO nanocrystal photocatalysts …

Left Atrial Model, Borna Sobati, Sarah Porello, Tess Pate

Biomedical Engineering

The objective is to produce an electrophysiological model of an adult human left atrium. This model will be used to test mapping probe catheters used for locating cardiac arrhythmias against current technology used in practice. Dr. Chris Porterfield requested this model and other physicians or probe catheter manufacturers may also use this product in the future. Dr. Porterfield also discussed the possibility of future senior project groups using the model as a bench test for designing new catheter tips. The model will precisely simulate electrical behaviors of the heart in normal as well as arrhythmic conditions. Ideally, the model will …

Generation And Use Of Femtosecond, Gigawatt, Near Infrared Laser Pulses From An Amplified, Mode-Locked, Ti:Sapphire Laser, David Anthony Valdés

Optical Science and Engineering ETDs

This work modeled the early to middle successes achieved in the field of ultrafast, high peak power optics, beginning with the work of Nobel Prize winners Donna Strickland and Gérard Mourou in 1985. In our work, 100 fs light pulses of around 800 nm were generated by a Ti:Sapphire oscillator, then amplified to approximately 30 GW peak power using a chirped pulse amplification system that included regenerative and multi-pass amplifiers. As a verification of our pulses having high peak powers and ultrashort durations, they were then used to strike water, glass, and a Kerr Cell. Supercontinuum generation was observed as …

Outdoor Education Center Concept Site Master Plan And Improvements As Designed By Wingineers, Christina Thibodeau

Honors Program: Senior Projects (Public)

This thesis builds on a basis of four years of engineering education to produce a final project for the capstone course. The idea behind this project was to provide a workable master plan and conceptual site improvements for a real application, the Outdoor Education Center in east Lincoln, Nebraska. The Boy Scouts of America Cornhusker Council and the University of Nebraska – Lincoln Department of Civil Engineering have cooperated throughout the Senior Design capstone course to make this possible for the students involved.

Predictive Modeling Of Fate And Transport Of Three Prevalent Contaminants In Midwest Agroecosystem Surface Waters: Nitrate-N, Atrazine, And Escherichia Coli, Samuel Hansen

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

The majority of streams and rivers in the United States (U.S.) are ecologically impaired, or threatened by anthropogenic stressors. Recent reports have found atrazine in drinking water to be associated with increased birth defects and incidences of Non-Hodgkin’s Lymphoma, with higher levels of significance from exposure to both atrazine and nitrate-N. In contrast, recent illnesses from E. coli contaminating vegetables that originated from irrigation water has increased awareness of identifying sources of E. coli entering irrigation reservoirs.

Methods to accurately predict atrazine and E. coli occurrence and potential sources in waterways continue to limit the identifying appropriate and effective prevention …

Uumanned Aerial Vehicle Data Analysis For High-Throughput Plant Phenotyping, Jiating Li

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

The continuing population is placing unprecedented demands on worldwide crop yield production and quality. Improving genomic selection for breeding process is one essential aspect for solving this dilemma. Benefitted from the advances in high-throughput genotyping, researchers already gained better understanding of genetic traits. However, given the comparatively lower efficiency in current phenotyping technique, the significance of phenotypic traits has still not fully exploited in genomic selection. Therefore, improving HTPP efficiency has become an urgent task for researchers. As one of the platforms utilized for collecting HTPP data, unmanned aerial vehicle (UAV) allows high quality data to be collected within short …

Methods To Remotely Eliminate Biofilm From Medical Implants Using 2.4 Ghz Microwaves, Brett Glenn

Mechanical Engineering Undergraduate Honors Theses

Infections associated with biofilm growth are usually challenging to eradicate due to their high tolerance toward antibiotics [11, 12]. Biofilms often form on the inert surfaces of medically implanted devices [13]. No matter the sophistication, microbial infections can develop on all medical devices and tissue engineering constructs [12]. Related infections lead to 2 million cases annually in the U.S., costing the healthcare system over $5 billion in additional healthcare expenses [12].

Novel solutions to biofilm’s microbial colonization span the spectrum of engineering and science disciplines. Yet a practical solution still does not exist. The research presented here will explore a …

Challenges And Opportunities Of Layered Cathodes Of Linixmnyco(1-X-Y)O2 For High-Performance Lithium-Ion Batteries, Jason Frank

Mechanical Engineering Undergraduate Honors Theses

High energy density lithium-ion batteries (LIBs) are widely demanded for portable electronic devices and electrical vehicles. Layered-structure LiCoO₂ oxide (LCO) has been the most commonly used cathode material in commercial LIBs. Compared to LCO, LiNi_1-x-yMn_xCo_yO₂ (NMC) cathodes are particularly attractive due to their reduced cost and higher capacity. Among the NMC cathodes, nickel-containing LiNi_0.5Co_0.3Mn_0.2O₂ (NMC532) is one of the most promising cathode materials undergoing intensive investigation, but suffers from a series of technical issues, such as structural instability, performance fading, and safety issues. In this …

Development Of Small-Scale And Low-Power Attitude Determination System For Nanoscale Satellites By Infrared Earth-Imaging Sensors, Zachary Tolar

Mechanical Engineering Undergraduate Honors Theses

Many space missions require that the spacecraft be oriented in a specific direction to operate correctly. ARKSAT 1, the University of Arkansas’s first satellite, is a 1U CubeSat designed to perform atmospheric spectroscopy from Low-Earth Orbit and as such requires precise attitude determination and control. Currently, attitude determination systems for 1U CubeSats with small space, low power, and low cost restrictions do not exist. This paper discusses the development of an earth-imaging infrared camera system for attitude determination on CubeSats and SmallSats that meets these requirements. Melexis MLX 90640 IR arrays and Microchip 8-bit microcontrollers are used to create infrared …

Modelling Palladium Decorated Graphene Using Density Functional Theory To Analyze Hydrogen Sensing Application, Sameer Kulkarni

Mechanical Engineering Undergraduate Honors Theses

Graphene is an exciting new material with many promising applications. One such application of graphene is gas sensing, when adsorbed with transition metals, notably Palladium. Therefore, it is of paramount importance to have appropriate ab initio calculations to calculate the various properties of graphene under different adsorbates and gasses. The first step in these calculations is to have a functioning base Density Functional Theory (DFT) model of pristine graphene decorated with Palladium. The computational methods described in this paper has yielded results for pristine graphene that have been confirmed many times in previous experimental and theoretical studies. Future work needs …

Real-Time Visual Multi-Target Tracking In Realistic Tracking Environments, Jacob Harley White

Theses and Dissertations

This thesis focuses on visual multiple-target tracking (MTT) from a UAV. Typical state-of-the-art multiple-target trackers rely on an object detector as the primary detection source. However, object detectors usually require a GPU to process images in real-time, which may not be feasible to carry on-board a UAV. Additionally, they often do not produce consistent detections for small objects typical of UAV imagery.In our method, we instead detect motion to identify objects of interest in the scene. We detect motion at corners in the image using optical flow. We also track points long-term to continue tracking stopped objects. Since our motion …

2019 Directory Of Indiana State, County, City And Town Officials Responsible For Road And Street Work, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Directory

Contact information for agency officials and employees responsible for Indiana’s local road infrastructure.