Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 12 of 12

Full-Text Articles in Engineering

Processing And Characterization Of Silicon Nitride For Rapid And Low-Level Detection Of Water Pathogens, Arielle H. Buchanan, Logan A. Chai Jun 2022

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 Jun 2022

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 …


Effect Of Oxygen Equivalence On The Strength And Toughness Of Ti-6al-4v Forgings, Kira Baylor, Clarissa Drouillard Jun 2022

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 …


Citric Or Acetic Acid Effects On The Crosslinking Of Pvoh, Samuel Carr, Erika Szaldobagyi Jun 2022

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 …


Stabilization Of Palm Wood Using Water-Based Impregnation, David A. Barnes Jun 2022

Stabilization Of Palm Wood Using Water-Based Impregnation, David A. Barnes

Materials Engineering

Impregnation is a technique for stabilizing wood that involves saturating the material in a liquid and allowing it to cure before use. Stabilization methods such as this are employed for a variety of reasons; chiefly, the low dimensional stability of wood and palm means that they are subject to several failure modes that arise from changing environmental conditions, such as cracking, warping, and bending. Samples of Borassus flabellifer, black palm, provided by DuraPalm were impregnated with solvent-based and water-based stabilizers, and untreated wood samples used as a control group. Kop-Coat WoodYouth® Plus was used as a solvent-based stabilizer, and impregnation …


Determining The Efficacy Of A Silica And Bacterial Cellulose Composite Model System, Hannah Martin, Daisy Kamp Jun 2022

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 …


Effects Of Release Materials And Temperature Ramp Rates On The Surface Finish Of Carbon-Fiber Composite Components, Sudeep Louis, Thucmy Dang, Ethan Schlocker Jun 2022

Effects Of Release Materials And Temperature Ramp Rates On The Surface Finish Of Carbon-Fiber Composite Components, Sudeep Louis, Thucmy Dang, Ethan Schlocker

Materials Engineering

Toray Advanced Composites is interested in improving their carbon fiber reinforced polymers (CFRP) manufacturing process by enhancing their control on the amount of surface roughness for varied customer preference. Surface roughness of CFRP is important in post-production processes including coating, priming, and painting. This project seeks to determine the effects of three release materials and two temperature ramp rates on the surface finish of CFRP. The release materials used were Tooltech, FEP, and Frekote 770-NC. The two initial temperature ramp rates were 1°F/min and 2°F/min. Surface roughness was measured using a profilometer and analyzed using Ra values. Ra is an …


Analysis Of Novel Corrosion Resistant Maraging Steels For Use In Additive Manufacturing, Bradley Michael Samuel, James Knowlton Smith Jun 2022

Analysis Of Novel Corrosion Resistant Maraging Steels For Use In Additive Manufacturing, Bradley Michael Samuel, James Knowlton Smith

Materials Engineering

Stainless maraging steel has been proven to be an industry standard material for plastic injection molds. Its high hardness and corrosion resistance extend the lifetime of the tool. This alloy system is also well-suited to additive manufacturing, which can be utilized to form internal cooling channels, further increasing tool life. Using Rapid Alloy Development (RAD) Oerilkon METCO is developing a new composition of stainless maraging tool steel that has high hardness/strength, is corrosion resistant, and has additive-capable melting and solidification properties. This study tests the hardness and corrosion resistance of the new RAD alloys against the current market competitor Corrax …


Investigation Of The Effects Of Cladding Layers On Longitudinal And Transverse Mechanical Properties In Composite Laminates, Rachel Potratz, Tiffany Foo, Joseph Kamlet Jun 2022

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 …


Non-Destructive Material Analysis Of Metals And Composites Via Thermography, Jonathan R. Doubt, James L. Chapman Jun 2022

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 …


Evaluating The Effects Of Granulated Rubber And Glass Fibers In Polymer Concrete As A Structural Material For Wafer Grinding Machines, Kevin Gabriel Kuehn, Philip Randall Streeter Jun 2022

Evaluating The Effects Of Granulated Rubber And Glass Fibers In Polymer Concrete As A Structural Material For Wafer Grinding Machines, Kevin Gabriel Kuehn, Philip Randall Streeter

Materials Engineering

Polymer concrete is a composite material used to replace cast iron and steel in wafer grinding machines for vibration damping. During the grinding and lapping processes of manufacturing silicon wafers, excessive vibrations may cause subsurface damage which requires additional polishing and reduces yield. Nine compositions containing various levels of granulated rubber and glass fibers were manufactured. CRM WRF-10 granulated rubber was examined at 0%, 5%, and 10% and Corning Cem-Fil glass fibers were added at 0%, 0.5%, and 1% by weight. Smooth-On EpoxAcast 690 epoxy resin was held constant at 16% for each composition. Crushed granite aggregate from Martin Marietta, …


Soil Degradation Of A Plastic Blend Of Opuntia Ficusindica Juice, Animal Protein And Beeswax, Isabel A. Gamez, Daniel R. Kava Jun 2022

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 …