Engineering Commons^™

Processing And Characterization Of Silicon Nitride For Rapid And Low-Level Detection Of Water Pathogens, Arielle H. Buchanan, Logan A. Chai

Materials Engineering

Water sanitation is a serious issue affecting the lives of many, and methods for assessing water cleanliness have been a major research interest for decades. Rapid and accurate water pathogen detection methods that can be performed in field applications have been a growing research focus, especially in low-income countries most affected by poor water quality. Silicon nitride was explored as a material for colorimetric water-pathogen sensing due to the large body of knowledge around its processing, and its isoelectric point. A bioassay of chlorophenol red-β-Dgalactopyranoside (CPRG) and β-galactosidase (β-gal) enzymes with Escherichia coli (E. coli) bacteria was used to examine …

In Situ Marine Biodegradation Of Poly(Lactic) Acid And Thermoplastic Starch Blends, Brittany Denicholas

Materials Engineering

Marine life has been suffering from macro- and microplastics since the inception of petroleum-based plastic. Bio-based biodegradable polymers such as PLA and TPS can help mitigate the damage done by petroleum plastics. Blending PLA and TPS can reduce the cost while preventing a significant effect on the material properties. PLA/TPS blend compositions such as 90/10, 80/20, 70/30 could be candidates for a solution. The PLA/TPS blends have been submerged in a marine environment at the Cal Poly Pier in Avila Beach for 8 weeks. Three sample sets containing three of each blend composition were collected every week and tested in …

Non-Destructive Material Analysis Of Metals And Composites Via Thermography, Jonathan R. Doubt, James L. Chapman

Materials Engineering

The Naval Surface Warfare Center, Port Hueneme Division, is interested in the development of non-destructive damage assessment of shipboard materials via drones at distance. Long Pulsed Thermography (LPT), a method of non-destructive evaluation, was investigated as a possible method for detecting damage in metals (5005h24 Al alloy and 1008 carbon steel) and composites (aramid fiber honeycomb sandwich structure) at distances from 0.5 m to 3.0 m. LPT was conducted using two 1000 W can lights to heat the samples, and a FLIR E8-XT thermal camera. The images were then analyzed using ImageJ software to determine if damage could be detected …

Citric Or Acetic Acid Effects On The Crosslinking Of Pvoh, Samuel Carr, Erika Szaldobagyi

Materials Engineering

Transportation and shipping processes are the most dangerous times for food due to harsh handling and frequent temperature changes. Plain corrugated boxes cannot withstand the damp environment caused by melting ice that is used to keep foods cold and fresh. To minimize damage, a protective polymer film coating can be applied. These coatings can be unsafe when used with food and will lead to excess waste by limiting the recyclability of the boxes. The purpose of this project was to produce nontoxic crosslinked PVOH films to determine suitability for a cost effective, biodegradable, and repulpable corrugated box coating. Polyvinyl alcohol …

Determining The Efficacy Of A Silica And Bacterial Cellulose Composite Model System, Hannah Martin, Daisy Kamp

Materials Engineering

Bacterial cellulose (BC) is a sustainable alternative to petroleum-based polymer films for synthetic leather applications. Synthesized by a symbiotic culture of bacteria and yeast, BC is a three-dimensional structure composed of cellulose microfibrils. However, pure BC lacks certain desirable properties such as high tensile strength. Previous studies have shown that loading BC with nanoparticles to form nanocomposites has improved BC’s mechanical properties. However, this was not studied as a function of particle size. This study focuses on using silica/BC nanocomposites to model the impact that particle size and silica soaking concentrations have on the uptake efficiency of these particles into …

Soil Degradation Of A Plastic Blend Of Opuntia Ficusindica Juice, Animal Protein And Beeswax, Isabel A. Gamez, Daniel R. Kava

Materials Engineering

Since the introduction of single use plastics in the early 1900s, their usage has increased exponentially. Unfortunately, due to this exponential increase there are negative environmental implications of their production, which requires further consideration. Currently, there are various waste disposal practices for SUPs, including landfilling, incineration, and recycling. Recent data revealed that only 14 % of plastic waste was recycled, with 40% of plastic waste being landfilled, while the rest of the plastic waste was incinerated or released to the environment at 14 % and 32 %, respectively. A potential solution to the plastic waste issue is developing a polymer …

Eagle Medical Tray Denesting & Debris Removal Process, Nicholas Allen Ungefug, Noah Chavez, Susana Shu-Lin Okhuysen, Michael Augustine Pennington

Industrial and Manufacturing Engineering

Eagle Medical Incorporated is a contract medical device packaging and sterilization company. The company purchases thermoformed medical packaging trays, which maintain the sterility of medical devices, from various manufacturers. To ensure packaging quality and to prevent cleanroom contamination, Eagle Medical inspects and sterilizes each blister tray that they order. This process is an essential non-value-added activity that creates a bottleneck. Cleanroom employees must stop packaging medical devices and attend to the processing of blister trays and packaging solutions. The blister trays arrive at Eagle’s facility in nested stacks. Vibration and movement during shipping further compresses the stacks, which makes separation …

Effect Of Oxygen Equivalence On The Strength And Toughness Of Ti-6al-4v Forgings, Kira Baylor, Clarissa Drouillard

Materials Engineering

Tensile testing and fracture toughness testing were conducted to establish a numerical relationship between interstitial content and performance in forged Ti-6Al-4V. The value of oxygen equivalence was used to represent the interstitial content by combining the weight percent of oxygen, carbon, and nitrogen. The correlation between oxygen equivalence and mechanical properties can be used to accurately predict the performance of forged parts. Samples of forged parts with varying levels of interstitial content were subjected to a recrystallization anneal at 75 F below the beta transus temperature to decrease microstructure variability across parts with a second anneal at 1300 F to …

Investigation Of The Effects Of Cladding Layers On Longitudinal And Transverse Mechanical Properties In Composite Laminates, Rachel Potratz, Tiffany Foo, Joseph Kamlet

Materials Engineering

The addition of cladding layers to composite laminates is used in industry to improve bond adhesion and the ease of manufacturing. However, there is no public data on the effects of cladding layers on the mechanical properties of composite components. To directly observe how cladding layers affect mechanical properties, four laminates with zero, one, two, and three cladding layers of twill fabric were added symmetrically to a biased core. The mechanical testing performed was tensile, short beam strength, and compression testing in the longitudinal and transverse directions. The measured strengths were related to the longitudinal properties of the core, and …

Kinetic Energy Harvesting Device For Long Distance Thru-Hikers, Jarod Reece Lyles, Ryan William Mclaughlin, Shaw Hawkeye Hughes, David Hernandez

Mechanical Engineering

The intent of this project was to design and build a device capable of harnessing biomechanical energy from a thru-hiker to charge electronic devices. To begin, we ruled out any potential solutions that could be intrusive to the hiking experience, limiting us to a device that could be placed in a backpack.

After defining the scope of the project, we ideated upon potential designs, and chose to move forward with a rotational generator based design. Detailed analysis included both system dynamics and vibrations based models, and from this analysis we developed a mechanical design in SOLIDWORKS®️ and a custom printed …

Wake Bifurcations Behind Two Circular Disks In Tandem Arrangement, Jianzhi Yang, Xiaowei Wu, Minghou Liu, Changjian Wang, Yuxin Wu, Zhihe Shen

Mechanical and Materials Engineering Faculty Publications and Presentations

The wake bifurcations behind two circular disks in tandem arrangement are investigated through numerical simulations. The separation distance between the disks, S/d, is chosen at 1, 2, 4, and 6, and the Reynolds number, Re, lies in the range of 100 Re 500. The wake dynamics are examined in terms of the flow structures as well as drag and lift coefficient characteristics. Seven main wake regimes are observed in the considered (Re, S/d) space: steady state (SS), Zig-zig (Zz) mode, standing wave mode, periodic state with reflectional symmetry breaking (RSB), periodic state with double-helical (DH) structures shedding, periodic state with …

Utilization Of Lidar Technology — When To Use It And Why, Levy Mcintosh, Brad Rister

Kentucky Transportation Center Research Report

Lidar technologies can assist transportation agencies during the design, construction, and maintenance phases of transportation projects. While Lidar has numerous applications, successfully deploying Lidar technologies is only possible if agencies have a solid understanding of their use cases and potential limitations. This report offers guidance the Kentucky Transportation Cabinet (KYTC) can use when making decisions on how to employ Lidar technologies in highway contexts. In addition to reviewing Lidar platforms and comparing Lidar-driven surveying to traditional surveying methods, the report examines challenges related to processing and storing Lidar data and the safety benefits Lidar technologies confer in the field. Brief …

Porcine Liver Injury Model To Assess Tantalum-Containing Bioactive Glass Powders For Hemostasis, Malvika Nagrath, Danielle Bince, Corwyn Rowsell, Deanna Polintan, Joao Rezende-Neto, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study evaluates compositions of tantalum-containing mesoporous bioactive glass (Ta-MBG) powders using a porcine fatal liver injury model. The powders based on (80-x)SiO₂-15CaO-5P₂O₅-xTa₂O₅ compositions with x = 0 (0Ta/Ta-free), 1 (1Ta), and 5 (5Ta) mol% were made using a sol–gel process. A class IV hemorrhage condition was simulated on the animals; hemodynamic data and biochemical analysis confirmed the life-threatening condition. Ta-MBGs were able to stop the bleeding within 10 min of their application while the bleeds in the absence of any intervention or in the presence of a commercial agent, AristaTM …

Hardware-Accelerated Ecg-Based True Random Number Generator, James Burrill, Sunjit Jayam

Electrical and Computer Engineering Senior Theses

Developing and proving the effectiveness of ECG-based TRNGs for use in cryptography applications related to implantable medical devices (IMDs) offers a novel approach to securing IMDs. Current ECG-based True Random Number Generators (TRNGs) are software orientated and computationally heavy with hardware implementations being suggested as one possible solution to make such TRNGs useful for the medical device industry. Hardware offers the opportunity to increase power efficiency through algorithmic optimization while maintaining device security. In this paper, we use Verilog design and FPGA simulation tools to demonstrate the potential for hardware-accelerated ECG-based TRNGs for use in low power cryptographic applications. This …

Surgical Tool Segmentation With Pose-Informed Morphological Polar Transform Of Endoscopic Images, Kevin Huang, Digesh Chitrakar, Wenfan Jiang, Isabella Yung, Yun Hsuan Su

Engineering: Faculty Publications

This paper presents a tool-pose-informed variable center morphological polar transform to enhance segmentation of endoscopic images. The representation, while not loss-less, transforms rigid tool shapes into morphologies consistently more rectangular that may be more amenable to image segmentation networks. The proposed method was evaluated using the U-Net convolutional neural network, and the input images from endoscopy were represented in one of the four different coordinate formats (1) the original rectangular image representation, (2) the morphological polar coordinate transform, (3) the proposed variable center transform about the tool-tip pixel and (4) the proposed variable center transform about the tool vanishing point …

A Novel Numerical Model Of Gelant Inaccessible Pore Volume For In Situ Gel Treatment, Jianqiao Leng, Xindi Sun, Mingzhen Wei, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Inaccessible pore volume (IAPV) can have an important impact on the placement of gelant during in situ gel treatment for conformance control. Previously, IAPV was considered to be a constant factor in simulators, yet it lacked dynamic characterization. This paper proposes a numerical simulation model of IAPV. The model was derived based on the theoretical hydrodynamic model of gelant molecules. The model considers both static features, such as gelant and formation properties, and dynamic features, such as gelant rheology and retention. To validate our model, we collected IAPV from 64 experiments and the results showed that our model fit moderately …

Comprehensive Review Of Polymer And Polymer Gel Treatments For Natural Gas-Related Conformance Control, Ali Al Brahim, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Conformance problems often exist in natural gas-related activities, resulting in excessive water production from natural gas production wells and/or excessive natural gas production from oil production wells. Several mechanical and chemical solutions were reported in the literature to mitigate the conformance problems. Among the chemical solutions, two classes of materials, namely polymer gels and water-soluble polymers, have been mostly reported. These systems have been mainly reviewed in several studies for their applications as water shutoff treatments for oil production wells. Natural gas production wells exhibit different characteristics and have different properties which could impact the performance of the chemical solutions. …

Comprehensive Review Of Polymer And Polymer Gel Treatments For Natural Gas-Related Conformance Control, Ali Al Brahim, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Conformance problems often exist in natural gas-related activities, resulting in excessive water production from natural gas production wells and/or excessive natural gas production from oil production wells. Several mechanical and chemical solutions were reported in the literature to mitigate the conformance problems. Among the chemical solutions, two classes of materials, namely polymer gels and water-soluble polymers, have been mostly reported. These systems have been mainly reviewed in several studies for their applications as water shutoff treatments for oil production wells. Natural gas production wells exhibit different characteristics and have different properties which could impact the performance of the chemical solutions. …

Improving Interprofessional Environmental Health Education Using The Leave No One Behind Framework, Daniel B. Oerther, Sarah E. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Wavelet Power And Shannon Entropy Applied To Acoustic Emission Signals For Corrosion Detection And Evaluation Of Reinforced Concrete, Jinrui Zhang, Ziye Kang, Dongshuai Hou, Biqin Dong, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Acoustic emission (AE) signals detected from corrosion test on a steel reinforced concrete beam subjected to the coupling effects of corrosive wet-dry cycles and static load are analyzed by power spectral density, wavelet transform, and Shannon entropy. The degradation process of the corroded reinforced concrete beam can be divided into four stages on the basis of the accumulated event number (AEN). Due to the difference of material properties, steel reinforcement and concrete matrix have distinguished AE features. The time-frequency characteristics of AE signals can reflect the microstructural degradation mechanism of steel corrosion and concrete cracking. The corrosion evaluation entails investigating …

Synthesis Of Dysprosium Oxychloride (Dyocl), Saehwa Chong, Brian J. Riley, José Marcial, Charmayne E. Lonergan, Derek A. Cutforth

Materials Science and Engineering Faculty Research & Creative Works

Dysprosium oxychloride, DyOCl, was synthesized using a simple hydrolysis method with DyCl₃·6H₂O. X-ray powder diffraction (XRD) data was used to determine the crystal structure. The DyOCl compound is isostructural to the matlockite (PbFCl) crystal structure and crystallizes in the tetragonal P4/nmm (#129) space group. The crystal structure contains the alternating cationic layers of (DyO)_n and anionic layers of nCl⁻ along the c-axis. The structural data including unit cell, volume, and density of DyOCl were compared to other rare-earth oxychloride data from the Inorganic Crystal Structure Database (ICSD) and our previous study on TbOCl. Fourier-transform …

Skip The Grid 2022: Solar Powered Refrigeration In The Navajo Nation, Heather L. Sailor

Construction Management

This paper summarizes the process of an interdisciplinary group of students and faculty at Cal Poly installing eleven off-grid solar systems for families of the Navajo nation. This paper further delves into the lean principals and prefabrication that made it possible as well as the lessons learned to increase the feasibility and scalability of repeating this project in the future. This project was a combined effort of an interdisciplinary group of Cal Poly students and faculty as well as company sponsors Solv Energy, Dometic USA, and Goal Zero, facilitated through the non-profit, Heart of America. The goal of this project …

Construction Of A Visitor Deck At City Farm Slo, Brett Bryan Jones

Construction Management

This paper will discuss the construction of my senior project. For my senior project, I completed the construction of an observation deck at City Farm SLO. City Farm SLO is a non-profit that provides food to local food banks and has educational gardens that allow students of all ages come to learn and volunteer their time. The deck is centrally located at the highest point on the property, making it a great lookout spot for visitors to view the entire farm. However, the location on top of the hill created challenges that we had to overcome. I completed my senior …

Tini-Based Bi-Metallic Shape-Memory Alloy By Laser-Directed Energy Deposition, Yitao Chen, Cesar Ortiz Rios, Braden Mclain, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

In this study, laser-directed energy deposition was applied to build a Ti-rich ternary Ti–Ni–Cu shape-memory alloy onto a TiNi shape-memory alloy substrate to realize the joining of the multifunctional bi-metallic shape-memory alloy structure. The cost-effective Ti, Ni, and Cu elemental powder blend was used for raw materials. Various material characterization approaches were applied to reveal different material properties in two sections. The as-fabricated Ti–Ni–Cu alloy microstructure has the TiNi phase as the matrix with Ti2Ni secondary precipitates. The hardness shows no high values indicating that the major phase is not hard intermetallic. A bonding strength of 569.1 MPa was obtained …

Thermal And Electrical Properties Of A High Entropy Carbide (Ta, Hf, Nb, Zr) At Elevated Temperatures, Evan C. Schwind, Michael J. Reece, Elinor Castle, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

The thermal and electrical properties were measured for a high entropy carbide ceramic, consisting of (Hf, Ta, Zr, Nb)C. The ceramic was produced by spark plasma sintering a mixture of the monocarbides and had a relative density of more than 97.6%. The resulting ceramic was chemically homogeneous as a single-phase solid solution formed from the constituent carbides. The thermal diffusivity (0.045–0.087 cm2/s) and heat capacity (0.23–0.44 J/g•K) were measured from room temperature up to 2000°C. The thermal conductivity increased from 10.7 W/m•K at room temperature to 39.9 W/m•K at 2000°C. The phonon and electron contributions to the thermal conductivity were …

Re-Assessing The Granite Heavy Civil Minor, Natalie H. Holnes

Construction Management

This research-based project analyzes issues within the Granite Heavy Civil Minor that contribute to declining student retention. This document specifically focuses on the program’s course curriculum and graduation date extensions as major drivers of student withdrawals from the minor. Two separate surveys were conducted from students within the minor and students who had dropped out of the minor, to gauge the specific issues students have with the program. The results concluded that many students dislike certain courses in the curriculum, such as CE 222 and CE 321, and felt that these required courses were unessential and unhelpful in preparing them …

Farm Stand Build And Service Days For The Ranch, John Reis Blackwood Calhoun

Construction Management

This paper outlines the building of a farm stand and service days done for The Ranch which works with the United Cerebral Palsy of Central California. The construction of a farm stand was requested by the client because they did not have one and would like to start selling the vegetables and fruits that they grow on their property. Additionally, there was an opportunity to do other improvements around the farm and simultaneously help brothers in the fraternity get service hours. To do this set up service days were set up where miscellaneous tasks around the farm such as spreading …

The Effect Of Inflation And The Pandemic On A Southern California Solar Company: A Case Study, Adrian Avila

Construction Management

Supply chain issues are causing panic in certain sectors of the economy particularly the solar sector. Solar energy already has problems that can affect its growth in the long term such as lack of government incentives, high cost, and energy curtailment. These problems are becoming more pronounced as the pandemic is prolonged. California is a state that has been encouraging the use of solar energy and has introduced incentives for its citizens to install solar. Because of this, solar companies in California may be able to more adequately circumvent issues and better excel economically than companies in other states. In …

San Luis Obispo Botanical Garden Alternative Learning Space- Preconstruction, Jonah Kirmse

Construction Management

This paper will review the process behind the preconstruction efforts for the creation of an alternative learning space within the San Luis Obispo Botanical Garden. The SLO Botanical Garden is a nonprofit that serves the local community by supporting public interest in the natural environment. The project sought to aid in the garden’s aforementioned mission by building upon their ability to provide outdoor education spaces. The project’s eventual completion was a collective effort that spanned across multiple disciplines, representing the building industry. The original intention of the project group was to complete the project from concept to construction, but delays …

Journeyman International: The Well Rusororo Project, Maranda F. Maliska

Construction Management

The Well Rusororo Project is based in Kigali, Rwanda on the same property of the Light Church of Kabuga. The non-profit organization, Journeyman International has teamed up with the Africa Mission Alliance in an effort to create a community campus available to the public. This project has been broken up into two stages; the first is a renovation of two existing buildings totaling 500 square meters, and the second is a ground-up construction of a 3,000 square meter multipurpose center. For their project-based senior project, this student volunteered with Journeyman International to assist in the creation of the following deliverables …