Engineering Commons^™

Methodology To Qualify And Monitor A Chemically Bonded Sand System Used In Foundries, Prayag Pravinbhai Patel

Dissertations

The goal of this dissertation is to establish a new quality control framework that combines a statistical process control (SPC) approach to casting quality for chemically bonded sand systems used in foundries. Foundries in the United States use the American Foundry Society standardized sand testing to monitor chemically bonded sand systems. These standardized tests are inefficient for two reasons. Firstly, standard tests are based on mechanical, physical, chemical and thermal properties of a sand system that do not consider interaction between these properties, but sand casting processes are inherently thermo-mechanical, thermo-chemical and thermo-physical. Secondly, these tests can only detect large …

Cooking Hand Multi-Tool, Amanda D. Meares, Amy H. Wilson, Ethan G. Littlejohn, Duania A. Evans

Biomedical Engineering

The purpose of this project was to devise a solution for Jorge Segura, a US Marine who was wounded in Afghanistan and had to have his non-dominant arm amputated above the elbow. His current prosthetic attachments are not suited to cooking tasks, so he needed a way to cook more effectively with either prosthetic attachments or accessibility devices. The main tasks that he needed help with was holding down food on cutting boards and stabilizing pots, pans, and bowls especially when stirring. After background research, exploring commercially available devices, and talking with our challenger, our solution was to design three …

Additive Manufacturing Powder Removal: Viper 2.0, Andrew D. Epperson, Sean Mccracken, Melissa O'Neil, Alex Ward

Mechanical Engineering

This report presents the final design review of this senior project team. The project is being sponsored by Lawrence Livermore National Laboratory, a federal design agency. Lawrence Livermore National Laboratory is interested in improving their metal additive manufacturing process. The goal of this senior project is to improve the efficiency and safety of a method currently being used to remove metal powders for additively manufactured components. A senior project team in 2017-2018 created the Vibration Induced Powder Evacuator and Reclaimer (VIPER), a device that uses a vibration motor to shake a printed part until it is clean from excess powder. …

Cal Poly Satellite Positioning Systems: "Thrust Or Bust!", Josh W. Neiman, Milena A. Milich, Gerardo Ramirez, Joshua A. Tran

Mechanical Engineering

Satellites need a way to make precise corrections to their orbit and positioning. The purpose of this project is to design a gimbal mechanism for Astranis that orients an ion thruster along a requested vector. The gimbal must produce any vector within a 2.5° cone in a thirty-minute window. Current systems are expensive and not well suited to this application. The design must be operable in a space environment and optimize mass, size, and reliability. Our design toggles between four discrete positions to achieve an average thrust vector. The gimbal accomplishes this using four solenoids that tilt a plate about …

C6 Wheels, Samuel L. Pizot, Luke Martin, Josh Warner, Jonah Levis

Mechanical Engineering

This document details the C6 Wheels project being undertaken for senior design. The objective is to design and manufacture carbon fiber reinforced polymer wheels for the Cal Poly Formula Society of Automotive Engineers (FSAE) team. The wheel shells will be used on FSAE’s competition vehicles. FSAE requested the wheels to improve the handling characteristics of their vehicles by reducing the unsprung and rotational mass. They have attempted carbon fiber wheels previously but have not yet run any on their vehicles. FSAE specifically proposed the design of carbon fiber shells with an aluminum center as opposed to full carbon fiber wheels …

Nano Fab Lab 63, Brian K. Deemer, Josh Clemons, Nick Brodine, Delaney Fitzsimmons

Mechanical Engineering

Lawrence Livermore National Laboratories (LLNL) has several steps in the production process for ceramic nanofiber tubes that they would like to improve - electrospinning, cutting, rolling, sealing and heat treating. We undertook the challenge to deliver LLNL with a semi-automated process that efficiently integrates the steps of cutting, rolling, and sealing to save time and improve control over end dimensions. In this document, we discuss the technical background of the manufacturing steps currently followed to create nanofiber tubes, identify which steps are incorporated in our prototype and explain how they will interface with one another, define the design requirements, present …

Restricted Crossings On Rural Highways, John Sangster, Tim Adams

Nebraska Department of Transportation: Research Reports

This study examines the potential for replacing the standard intersection design at two-way stop control (TWSC) and all- way stop control (AWSC) intersections along rural highways with a roundabout or a restricted crossing u-turn (RCUT) facility. The geometry of the RCUT design prohibits left and through movements from the side road, and provides a u-turn location downstream from the main crossing. This type of facility has been implemented for rural highways extensively in both Maryland and North Carolina, as well as in limited cases in many other states such as Minnesota and Missouri, with the potential to serve as a …

Assessing The Impact Of Game Day Schedule And Opponents On Travel Patterns And Route Choice Using Big Data Analytics, Anuj Sharma, Vesal Ahsani

Nebraska Department of Transportation: Research Reports

The transportation system is crucial for transferring people and goods from point A to point B. However, its reliability can be decreased by unanticipated congestion resulting from planned special events. For example, sporting events collect large crowds of people at specific venues on game days and disrupt normal traffic patterns.

The goal of this study was to understand issues related to road traffic management during major sporting events by using widely available INRIX data to compare travel patterns and behaviors on game days against those on normal days. A comprehensive analysis was conducted on the impact of all Nebraska Cornhuskers …

Atmospheric Water Harvesting: An Experimental Study Of Viability And The Influence Of Surface Geometry, Orientation, And Drainage, Carson T. Hand

Master's Theses

Fresh water collection techniques have gained significant attention due to global dwindling of fresh water resources and recent scares such as the 2011-2017 California drought. This project explores the economic viability of actively harvesting water from fog, and techniques to maximize water collection. Vapor compression and thermoelectric cooling based dehumidifier prototypes are tested in a series of experiments to assess water collection capability in foggy environments, and what parameters can increase that capability. This testing shows an approximate maximum collection rate of 1.25 L/kWh for the vapor compression prototype, and 0.32 L/kWh for the thermoelectric cooling prototype; compared to 315 …

Evaluation Of Tensile Properties For Selective Laser Melted 316l Stainless Steel And The Influence Of Inherent Process Features, Paul Swartz

Master's Theses

Optimal print parameters for additively manufacturing 316L stainless steel using selective laser melting (SLM) at Cal Poly had previously been identified. In order to further support the viability of the current settings, tensile material characteristics were needed. Furthermore, reliable performance of the as-printed material had to be demonstrated. Any influence on the static performance of parts in the as-printed condition inherent to the SLM manufacturing process itself needed to be identified. Tensile testing was conducted to determine the properties of material in the as-printed condition. So as to have confidence in the experimental results, other investigations were also conducted to …

Multiple Input, Single Output Dc-Dc Conversion Stage For Dc House, Jason Baltierrez

Master's Theses

n this thesis project, a proposed architecture for the multiple input, single output conversion stage for the DC House was designed, simulated, and tested. This architecture allows for multiple different input sources to be used to create a single higher power output source. The design uses a DC-DC boost converter with a parallelable output which has been demonstrated to allow increased total output power as a function of the number of input sources available. The parallelable output has been shown to distribute load amongst the input sources relatively closely to optimize the system. This approach is also desirable since it …

Multi-Vector Tracking Of Wifi And Zigbee Devices, Calvin Andrew Laverty

Master's Theses

Location privacy preservation has shifted to the forefront of discussions about next generation wireless networks. While pseudonym-changing schemes have been proposed to preserve an individual's privacy, simulation has shown that new association attack models render these schemes useless. The major contribution of this thesis is the implementation of a tracking network with commodity hardware on the California Polytechnic State University campus which leverages the combination of de-anonymization strategies on captured wireless network data to show the effectiveness of a pseudonym-changing scheme for wireless identification across WiFi and Zigbee protocols.

Surveying Underwater Shipwrecks With Probabilistic Roadmaps, Amy Jeannette Lewis

Master's Theses

Almost two thirds of the Earth's surface is covered in ocean, and yet, only about 5% of it is mapped. There are an unknown amount of sunken ships, planes, and other artifacts hidden below the sea. Extensive search via boat and a sonar tow fish following a standard lawnmower pattern is used to identify sites of interest. Then, if a site has been determined to potentially be historically significant, the most common next step is a survey by either a human dive team or remotely operated vehicle. These are time consuming, error prone, and potentially dangerous options, but autonomous underwater …

Colloid Thruster To Teach Advance Electric Propulsion Techniques To Post-Secondary Students, Alexander M. Powaser

Master's Theses

Colloid thrusters, and electrospray thrusters as a whole, have been around since the 1960s. When they were first developed, the high efficiency and fine thrust control was overshadowed by the high power requirement for such a low thrust that the system provides. This caused the technology to be put on hold for aerospace applications. Now, as small satellites are becoming more prevalent, there has been a resurgence in interest in electrospray thruster technology. The recent advancements in tech- nology allow electrospray thrusters to use significantly less power and occupy less volume than their predecessors. As electrospray technology continues to advance, …

Degradation Of Emerging Contaminants By Advanced Oxidation Using Multi-Walled Carbon Nanotubes And Continuous Ozone Injection, Emily N. Miller

Master's Theses

With a growing population and continuous accumulation of pollutants, water resources worldwide are quickly being depleted. Drastic improvements need to be made in both water conservation and treatment. Advanced oxidation processes (AOPs) have been developed to go above and beyond the capabilities of traditional wastewater treatment facilities to eliminate emerging contaminants from our water systems. AOPs increase the generation of hydroxyl radicals (•OH) in oxidation reactions, which are less selective and more reactive than other oxidants, such as ozone, so they are more effective at degrading persistent compounds. This study explored an AOP that utilizes ozonated multi-walled carbon nanotubes (MWCNTs) …

Characterization Of Resistance Change In Stretchable Silver Ink Screen Printed On Tpu-Laminated Fabrics Under Cyclic Tensile Loading, Corey R. Sutton

Master's Theses

A stretchable silver ink was screen printed to TPU sheets, then tensile coupons of the TPU, both bare and laminated to cotton, Denim and spandex fabric, were subjected to 1000 cycles of 20% uniaxial strain. In-situ resistance measurements of printed traces were processed to generate datasets of maximum and minimum resistance per cycle. A mechanistic fit model was used to predict the resistance behavior of the ink across TPU/fabric levels. The results show that traces strained on TPU laminated to spandex (polyester) fibers had an average rate of increase in resistance significantly lower than that of traces strained on bare …

Theoretical Analysis And Experimental Realization Of Highly Effective Acceptor Ionization In Gan Via Mg Co-Doped With 4d-Element (In), Zhiqiang Liu, Xiaoyan Yi, Junxi Wang, Ian Ferguson, Na Lu, Jinmin Li

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, we clarify the underlying physics and the acceptor ionization process in the In-Mg co-doping GaN. The fundamental understandings are also applicable for other co-doping nitride systems. We show the effective acceptors ionization stems mainly from the band structure tuning effect of the 4d orbitals of In atoms. In addition, temperature dependent defect-related photoluminescence analysis was proposed to examine the energy position of Mg impurity levels, which is crucially important in the design for high p-doping. Finally, a hole concentration, which is nearly one order of magnitude higher than what is typically achievable by direct Mg-doping, was achieved.

A Data Driven Approach To Identify Journalistic 5ws From Text Documents, Venkata Krishna Mohan Sunkara

School of Computing: Dissertations, Theses, and Student Research

Textual understanding is the process of automatically extracting accurate high-quality information from text. The amount of textual data available from different sources such as news, blogs and social media is growing exponentially. These data encode significant latent information which if extracted accurately can be valuable in a variety of applications such as medical report analyses, news understanding and societal studies. Natural language processing techniques are often employed to develop customized algorithms to extract such latent information from text.

Journalistic 5Ws refer to the basic information in news articles that describes an event and include where, when, who, what and why …

Persuasion, Political Warfare, And Deterrence: Behavioral And Behaviorally Robust Models, William N. Caballero

Theses and Dissertations

This dissertation examines game theory models in the context of persuasion and competition wherein decision-makers are not completely rational by considering two complementary threads of research. The first thread of research pertains to offensive and preemptively defensive behavioral models. Research in this thread makes three notable contributions. First, an offensive modeling framework is created to identify how an entity optimally influences a populace to take a desired course of action. Second, a defensive modeling framework is defined wherein a regulating entity takes action to bound the behavior of multiple adversaries simultaneously attempting to persuade a group of decision-makers. Third, an …

An Integrated Model To Use Drilling Modular Machine Tools, Ana Vafadar, Majid Tolouei-Rad, Kevin Hayward

Research outputs 2014 to 2021

Modular machine tools provide a platform for drilling-related operations within automotive companies. The use of these machine tools is widespread; however, manufacturers wishing to use this technology frequently face the challenge of selecting the most appropriate manufacturing system. Accordingly, a comprehensive feasibility analysis procedure is required to assist decision-makers before any investment is made on the preparation of detailed machine design or purchase one. This paper presents a model, which collects the previous works of the authors. To do this, an integrated framework for decision-making of using machine tools is developed. The aim of this model is to enable users …

An Examination Into The Defining Characteristics Of Flexible Solar Aircraft Configurations Through Optimization, Taylor Mcdonnell, Andrew Ning

Faculty Publications

This paper examines the defining characteristics of various solar aircraft configurations through gradient-based multidisciplinary design optimization. We first present a general gradient-based solar aircraft optimization framework which accounts for nonlinear aeroelastic effects resulting from structural flexibility. We then apply this framework to several discrete SR- HALE aircraft geometric, structural, and propulsion system configuration choices to determine the defining characteristics of each configuration choice.

Adapted Trailer Hitching System, Joseph Neil Hearn, Maxwell M. Selna, Maximilian D. Cossalter, Eric B. Ringsrud

Mechanical Engineering

This report highlights the entire design process of an adapted trailer hitching system for Taylor Morris: a navy veteran and quadruple amputee. This begins with problem definition through customer and product research. Objectives are generated after the problem is defined and the boundary of the project is set. This outcome of the project focuses on modifications/improvements to the vehicle side of the problem and leaves the trailers untouched. Engineering specifications are developed to constrain the concept design direction, which ultimately dictates the outcome of the final design. The final design is used as a basis to manufacture a structural prototype …

Reduce, Reuse, Reengineer, Neil Ryan Robertson, Anthony James Beers

Architectural Engineering

Our senior project is a research exploration of renewable energy. We recognized there is a major need in the world for the advancement of green power sources. For our project, we wanted to go beyond what we have learned in our Cal Poly architectural engineering classes and to use some of our own creativity to investigate the possibilities of renewable energy from a structural perspective. The guiding question we asked ourselves was, “as architectural engineering students, how could we shift our world to use more renewable energy?” To start our journey off, was the original inspiration from the work of …

Pedestrian Bridge In Tanzania, Maja Sagaser, Karina Rosales

Architectural Engineering

This senior project originated to address the need of the community of Same, Tanzania. There is a deep and wide ravine which floods, making the path many adults and children take to the Majevu Primary School increasingly difficult and dangerous. This report encapsulates all of the steps taken to complete an approved final design for a footbridge to be constructed over this ravine. It includes the project overview, the architectural and structural design process, as well as the important considerations. There are also structural drawings that include plans, elevations, and details.

Steel Test Set-Up For Non-Ductile Concrete Shear Walls, Colin S. Ridgley

Architectural Engineering

The purpose of this project was to provide a robust test set-up for the thesis work being conducted by graduate students, Jerry Luong & Rory de Sevilla. Their research aims to evaluate the feasibility of using fiber-reinforced polymer wraps and splay anchors to retrofit non-ductile concrete shear walls through a series of tests on reinforced concrete walls.

Four key constraints governed the design of the test set-up. First, the wall can be cyclically, laterally loaded to develop data for comparison with theoretical analysis methods. Second, the wall can be axially loaded to simulate interaction effects and prevent a sliding failure …

Analog Single Sideband-Pulse Width Modulation Processor For Parametric Acoustic Arrays, Vikrant A. Marathe

Master's Theses

Parametric acoustic arrays are ultrasonic-based loudspeakers that produce highly directive audio. The audio must first be preprocessed and modulated into an ultrasonic carrier before being emitted into the air, where it will self-demodulate in the far field. The resulting audio wave is proportional to the double time-derivative of the square of the modulation envelope. This thesis presents a fully analog processor which encodes the audio into two Pulse Width Modulated (PWM) signals in quadrature phase and sums them together to produce a Single Sideband (SSB) spectrum around the fundamental frequency of the PWM signals. The two signals are modulated between …

Improved Reliability Of Stormwater Detention Basin Performance Through Water Quality Data-Informed Real-Time Control, Sazzad Sharior, Walter M. Mcdonald, Anthony J. Parolari

Civil and Environmental Engineering Faculty Research and Publications

Stormwater detentions basins are designed to capture stormwater to reduce and delay peak flows and to improve water quality. A novel technology proposed to improve basin performance is real-time, active control of the basin outflow, in so-called “smart” stormwater systems. Existing studies demonstrate the performance of active controls that respond in real-time to basin water level, detention time, and rainfall forecast for one or a small number of rainfall events. We hypothesize that the performance of these active controls can be improved by incorporating real-time water quality data into the control algorithm. In addition, we hypothesize that active control performance …

Microscope System, Virginia Brannaman, Gavin Shavey, Ricardo Lasa

Biomedical Engineering

This project aims to improve upon the current microscope stand for the Olympus compound microscope in the Microcirculation and Vascular Regeneration (MaVR) laboratory in order to minimize angular deflection of the microscope objective with respect to surgical stage.

Modifying Casting Parameters To Improve The High Temperature Ductility Of Investment Cast Nickel-Based Superalloy Pwa 1455, Lars Alexander Hedin, Cole Magnum Introligator

Materials Engineering

PCC Structurals, an industry leader in superalloy investment castings, has observed inconsistencies in the stress rupture performance of polycrystalline nickel-based superalloy PWA 1455. PCC has changed their casting parameters to reduce the thermal gradient during cooling but have been unable to correlate these changes with an increase in stress rupture elongation. Metallographic examination of past samples indicated microstructures composed of non- equiaxed dendritic grains with mean diameter of .021 inches along the test axis. A similar study on polycrystalline superalloys has indicated that excessive superheat temperatures above the liquidus can result in large grains identical to those observed, limiting the …

Effect Of Solder Joint Flux Residue On Medical Guide Wire Performance, Rebecca Lisberg, Enlly Bugarin Rodriguez

Materials Engineering

The effect of residual soldering flux on the mechanical properties of 304 stainless-steel core medical guide wires was analyzed. A soldering process joins the metallic components of the distal end of a medical guide wire product. Acidic soldering flux is used to prepare the surfaces of the metallic substrates. Manufacturing protocol utilizes an ultrasonic bath to remove excess flux from the soldered joints. Sample groups underwent different levels of cleaning: no cleaning, partial cleaning, and full ultrasonic bath cleaning to obtain varying residual flux levels. Experimental sample groups underwent corrosion acceleration in an environmental chamber at 37°C and 85% relative …