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Full-Text Articles in Engineering

Effect Of Environmental And Ultraviolet Degradation On The Albedo Of Polyethylene Sheet Materials For Improved Energy Harvesting By Bifacial Photovoltaic Power Plants, William A. Jang, Roxy H. Jackson-Gain Jun 2023

Effect Of Environmental And Ultraviolet Degradation On The Albedo Of Polyethylene Sheet Materials For Improved Energy Harvesting By Bifacial Photovoltaic Power Plants, William A. Jang, Roxy H. Jackson-Gain

Materials Engineering

Solar energy farms typically utilize monofacial photovoltaic (mPV) cells in their arrays to capture direct sunlight to produce renewable energy. However, the efficiency of these farms can be increased by 2 – 6% through the implementation of bifacial photovoltaic cells (bPV). These bPV cells function by capturing incident ultraviolet (UV) light energy that is reflected off the surface to increase its overall energy production. The amount of UV energy that is reflected is dependent on the albedo value of surface, which is a measure of energy reflectance. In this study, samples of unreinforced polyethylene (PE), scrim-reinforced polyethylene (SR-PE), and woven …


Production Optimization Of Ring-Banded Spherulitic Crystals Of Poly (3-Butylthiophene-2,5-Diyl) Using Controlled Solution Evaporation, Frederick Paul Henderson Iii Jun 2019

Production Optimization Of Ring-Banded Spherulitic Crystals Of Poly (3-Butylthiophene-2,5-Diyl) Using Controlled Solution Evaporation, Frederick Paul Henderson Iii

Materials Engineering

Conductive polymers can carry a charge due to the presence of excess electrons along the carbon backbone. By growing these polymers into crystals, the usual insulative isotropic matrix that polymers form will be replaced with anisotropic regions where conduction is possible parallel to the crystal lattice growth direction. In previous research, while growing sphere shaped crystals it was observed that a few would exhibit rings that formed parallel to the circumference of the sphere. In this project, the conditions to produce this ring structure were examined by looking at two polymer solutions (with carbon disulfide or dichlorobenzene as solvent) and …


Maximizing Poly(3-Butylthiophene-2,5-Diyl) Electrical Conductivity By Maximizing Transcrystal Growth, Edward Alexander Bicknell Jun 2019

Maximizing Poly(3-Butylthiophene-2,5-Diyl) Electrical Conductivity By Maximizing Transcrystal Growth, Edward Alexander Bicknell

Materials Engineering

Polymers are generally considered electrical insulators. Despite this, research in the mid 1970’s found that polymers consisting of a conjugated backbone structure could become electrically conductive upon doping.1 The conjugated polymer analyzed for this project was poly(3-butylthiophene-2,5-diyl) (P3BT). Transcrystals have been found as a way to promote electrical conductivity through mechanisms including π bond atomic orbital overlap and electron mobility.2 In theory, maximizing transcrystal length would also maximize P3BT electrical conductivity, increasing its applicable use in electronic devices. The goal of this project was to determine a methodological way to maximize P3BT electrical conductivity by producing the longest transcrystal length …


Non-Toxic Soil Thickeners For Reducing Mudslide Intensity, Miranda Miao, Isaac Blackburn, Erika Haley Yao Jun 2019

Non-Toxic Soil Thickeners For Reducing Mudslide Intensity, Miranda Miao, Isaac Blackburn, Erika Haley Yao

Materials Engineering

Non-toxic food thickeners were investigated as a solution for thickening mud to mitigate the effects of mudslides. All soil was obtained from a site on the California Polytechnic State University campus where a mudslide occurred in 2017. Guar gum was mixed into the soil at 1 wt% and 10 wt% of the moisture content in the soil. Whey protein was mixed into the soil at 2 wt% and 19 wt% of the moisture content in the soil. The soils’ liquid limit was found using the Casagrande cup testing method. Liquid limit testing indicated that thickeners raised the liquid limit, most …


Exploring The Relationship Between Cellular Structure And Mechanical Properties Of Polymer Foams, Timothy Lee Tan Jun 2018

Exploring The Relationship Between Cellular Structure And Mechanical Properties Of Polymer Foams, Timothy Lee Tan

Materials Engineering

Polymer foams are the material of choice for applications that require comfort, cushioning, and high energy absorption. While popular, the relationship between their microstructure and their mechanical properties is not yet strongly predictable. The aim of this project is to look at the different relationships between the area or volume occupied by pores compared to the amount of solid material and determine which method of quantifying this relationship will provide the best prediction of mechanical properties. To examine this relationship, foams of various densities made from either ethylene-co-vinyl acetate or thermoplastic polyurethane were first physically characterized through three methods: (1) …


Mechanical Behavior Of Compression Molded Polyethylene Terephthalate, Daniel Cole Greinke, Paul Jackson Mcewan, Dan Tran Jun 2014

Mechanical Behavior Of Compression Molded Polyethylene Terephthalate, Daniel Cole Greinke, Paul Jackson Mcewan, Dan Tran

Materials Engineering

The purpose of this project was to investigate the effects of time, temperature, and pressure on the tensile strength and elastic modulus of recycled PET. Compression molding trials were performed on shredded PET bottles to produce tensile test specimens conforming to ASTM D638-03. Aluminum molds containing the PET were mechanically fastened together at the desired pressure and heated in an electric oven. The resulting specimens were subjected to tensile testing for analysis. This screening experiment failed to generate any statistically significant data concerning the factors of interest. These preliminary results may be used to design a more systematic follow-up study.


Preparation Of A Polylactic Acid With Hydroxyapatite Reinforcement Composite, Odessa N. Quezon Jun 2013

Preparation Of A Polylactic Acid With Hydroxyapatite Reinforcement Composite, Odessa N. Quezon

Materials Engineering

Biodegradable polymers are a prime material choice for temporary biomedical devices due to its ability to degrade into non-toxic products for their use in vivo. However, polylactic acid (PLA) by itself lacks the sufficient strength and stiffness to permit their use as its properties begin to decrease as the polymer degrades. To improve the polymer’s mechanical properties, hydroxyapatite (HA) will be added to the PLA solution to act as reinforcement. The chemical property, glass transition temperature of a polymer, also plays a key role in the mechanical properties of the polymer. PLA’s glass temperature is 130⁰F. A polymer that …


The Mitigation Of Eutrophication Using Microporous Polymer Membranes To Control Algae Growth, Christopher R. Riley Jun 2012

The Mitigation Of Eutrophication Using Microporous Polymer Membranes To Control Algae Growth, Christopher R. Riley

Materials Engineering

A system was designed to mitigate the accelerated process of anthropogenic eutrophication. This system aimed to contain Chlorella Vulgaris microalgae cells within an enclosed polymer membrane pouch while allowing for water and nutrients to diffuse through the pouch. As a test model, a 10 gallon aquarium was partitioned into three sections using polycarbonate membranes with 1 micron pore diameters. Each section was then gradually filled with a deionized water and Bristol solution recommended for microalgae growth. Phosphate and nitrate were added to Section A of the aquarium and allowed to diffuse throughout the tank. A water pump was used to …