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Full-Text Articles in Engineering

The Environmental Impact Assessment Of Cal Poly's Manufacturing Laboratory, Yoonho Mark Kim Jun 2014

The Environmental Impact Assessment Of Cal Poly's Manufacturing Laboratory, Yoonho Mark Kim

Materials Engineering

The purpose of the study is to obtain basic understanding of the sustainability of Cal Poly IME 144 laboratory. Since the general condition of the lab prevents precise, efficient data collection, fuzzy logic is used to provide an overview of the laboratory's sustainability. Aluminum chips, brass chips, and paper waste are identified as primary waste streams. Electric usage of the laboratory is approximately calculated based on the machines' running time. Fuzzy logic system with three inputs and one output is designed in the Matlab software environment with Simulink to simulate a model for the laboratory's sustainability. Also the study suggests …


Material Composition And Toxicology Of Cosmetic Products, Hilda Gonzalez Jun 2014

Material Composition And Toxicology Of Cosmetic Products, Hilda Gonzalez

Materials Engineering

In today’s modern society, the U.S. Food and Drug Administration regulates many industries to protect consumers’ health; the cosmetics industry is not one of them. Through self-regulation, companies continue to sell products for topical use on the body that have been known to contain toxic chemicals with little to no testing on the effects they have on the human body. The purpose of this project was to determine the content of such known toxins in five different brands of face powders. X-Ray Diffraction (XRD) was used to verify the primary component and Inductively Coupled Plasma-Optical Emissions Spectroscopy (ICP-OES) was used …


Prediction Of Tribological Behavior Of Candidate Materials For Rotor Seals, John W. Franzino, Will F. Michul Jun 2014

Prediction Of Tribological Behavior Of Candidate Materials For Rotor Seals, John W. Franzino, Will F. Michul

Materials Engineering

To reduce high costs associated with manufacturing and testing materials for rotor seals, a procedure needs to be developed to quickly and accurately test candidate materials as they are released. The test should reduce the amount of fabrication required and model working conditions in order to accurately assess the tribological behavior of candidate materials. A possible solution was examined that utilized a rig meant to model operational stresses and wear. Compression modulus data was then taken in order to quantify the accumulation of damage due to microcracking, the primary mode of failure, through a damage index parameter. Testing results concluded …


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.


The Effects Of Austempering And Cryogenic Processing On The Mechanical Properties Of Forged E4340 Steel For Automotive Engine Connecting Rods, Aaron Taylor Ludlow Jun 2014

The Effects Of Austempering And Cryogenic Processing On The Mechanical Properties Of Forged E4340 Steel For Automotive Engine Connecting Rods, Aaron Taylor Ludlow

Materials Engineering

The components in top-fuel dragster and stock car engines undergo significantly more force than their production passenger vehicle counterparts do. Therefore, they must be manufactured and processed to withstand those forces so that they do not catastrophically fail while in service. In this project, the effects of austempering and adding a cryogenic processing step to the control quench and double temper heat treatment on the tensile and hardness properties of E4340 high-strength steel were examined. Tensile test samples were machined from raw connecting rod forgings and underwent either a quench-double temper heat treatment, an austempering heat treatment, or the quench-double …


Characterization Of A Thin Film Composite Membrane: Fluorinated Copolymer In A Carbon Nanotube Matrix, Eric P. Bonaventure, Michael A. Brew, Cynthia R. Shannon Jun 2014

Characterization Of A Thin Film Composite Membrane: Fluorinated Copolymer In A Carbon Nanotube Matrix, Eric P. Bonaventure, Michael A. Brew, Cynthia R. Shannon

Materials Engineering

IDEX Health and Science has created a thin-film composite membrane consisting of a carbon nanotube matrix impregnated with a fluorinated copolymer called Teflon® AF 2400. This membrane is being studied for use in degassing chambers of analytical instruments such as a High Pressure Liquid Chromatography (HPLC) degassing modules. The level of impregnation of the Teflon® in the carbon matrix affects the diffusion properties which are crucial for the performance of the membrane. Scanning Electron Microscopy (SEM) characterization techniques were used to measure the outer Teflon® and the inner carbon matrix layer thickness. The outer Teflon® and inner carbon matrix layer …


Fabrication And Testing Of Arabinan Cellulose Nanocomposites, Ross Johnson, Austin Rosso, Nick Semansky Jun 2014

Fabrication And Testing Of Arabinan Cellulose Nanocomposites, Ross Johnson, Austin Rosso, Nick Semansky

Materials Engineering

Inspired by the structure and composition of cactus spines found in nature, arabinan-cellulose nanocomposites were fabricated into thin films and tested for mechanical stiffness. The composites consisted of varying amounts of nanocrystalline cellulose reinforcement suspended in an arabinan matrix. Both materials are polysaccharides and are known to be biodegradable and food safe. The thin film samples were tensile tested using a dynamic mechanical analysis machine both as-cast and after a heat-treatment. The heat treatment of the arabinan itself resulted in an order of magnitude increase in stiffness, while the cellulose reinforced composites increased roughly six fold. The arabinan-50 wt% cellulose …


Characterization Of Pressure Driven And Electro-Kinetically Driven Flow In A Micro-Fluidic Chip Using Particle Imaging Velocimetry, Alexis Paige Weckel Jun 2014

Characterization Of Pressure Driven And Electro-Kinetically Driven Flow In A Micro-Fluidic Chip Using Particle Imaging Velocimetry, Alexis Paige Weckel

Materials Engineering

The goal of this research is to compare electro-kinetic and pressure driven flow rates and velocity profiles (near wall vs. middle) in a microfluidic chip made of PDMS using particle imaging velocimetry (PIV) of an aqueous solution of fluorescent polystyrene (PS) particles using a laser confocal microscope (LCM). Microfluidic channels were fabricated out of PDMS using a SU-8 mold to be 25mm long and 180um by 1000um. Pressure-driven data did not show the expected parabolic profile because of the large width to depth ratio. In addition, data showed a calculated average significantly higher than the projected particle velocity through the …


The Effect Of Silicon On The Electrochemical Corrosion Resistance Of Carbon Steel, Loan Faget, Michael S. Rouse Jun 2014

The Effect Of Silicon On The Electrochemical Corrosion Resistance Of Carbon Steel, Loan Faget, Michael S. Rouse

Materials Engineering

The purpose of this study was to investigate how the silicon (Si) content of carbon steels affects their electrochemical corrosion resistance. Tests were conducted using concentrated HCl and carbonated water on three carbon steels with different levels of silicon: 0.02, 0,19, and 0.94 weight percent. Like H2S, the prime concern of Chevron, HCl and CO2 are corrosive components in oil refinery. Electrochemical properties were measured using a potentiodynamic test outlined in Standard ASTM G59-97: Test Method for Conducting Potentiodynamic Polarization Resistance Measurements. Previous studies have determined that adding silicon to steel increases the corrosion resistance; however, results show that corrosion …


Second Generation Design Of An Operator Independent Teflon Coating Adhesion Tester For Coronary Guidewires, Garrett L. Wong Jun 2014

Second Generation Design Of An Operator Independent Teflon Coating Adhesion Tester For Coronary Guidewires, Garrett L. Wong

Materials Engineering

No abstract provided.


Development Of Low Temperature, Aqueous Synthesis Method Of Lead Sulfide Quantum Dots, Albert Nakao, Colin Yee Jun 2014

Development Of Low Temperature, Aqueous Synthesis Method Of Lead Sulfide Quantum Dots, Albert Nakao, Colin Yee

Materials Engineering

Quantum dots have become an active area of research in the past decade due to their unique properties. Quantum confinement effects allow for efficient spectral conversion and size tunable fluorescence and absorption peaks. Near infrared spectral converting lead sulfide quantum dots have potential applications in solar power, biological imaging and communications technology. However at Cal Poly, lead sulfide dots have not been synthesized. The quantum dot synthesis currently adapted at Cal Poly encompasses organometallic precursors at high reaction temperatures, producing cadmium selenium dots. The organometallic approach has been found to produce nanocrystals with high quality photoluminescence, but due to its …


A Process Development Study On Reducing The Anisotropy While Maintaining The Strength Of Extruded Aluminum Alloy 2195 Through Heat Treatment, Theodore James Arehart Jun 2014

A Process Development Study On Reducing The Anisotropy While Maintaining The Strength Of Extruded Aluminum Alloy 2195 Through Heat Treatment, Theodore James Arehart

Materials Engineering

The purpose of this study was two-fold: develop an aging curve for extruded 2195 aluminum and test the magnitude of the anisotropy in the extrusion throughout the aging process. Two aging curves were developed, one at 290oF and the other at 320oF, through hardness tests of aged samples. The hardness was found to change, from approximately 72 HRB to 90 HRB, within the first 6 hours and not change more than 2 HRB in the 42 hours following. It was determined that the 320oF temperature was more promising due to faster aging time, and …


Electrochemical Characterization Of Precious Metal Braze Alloys Using Potentiodynamic Polarization, Maxwell Glen Martin, Mason Gregory Morgan, Matthew David Vance Jun 2014

Electrochemical Characterization Of Precious Metal Braze Alloys Using Potentiodynamic Polarization, Maxwell Glen Martin, Mason Gregory Morgan, Matthew David Vance

Materials Engineering

This study aimed to characterize the electrochemical behavior of six precious metal braze alloys by performing potentiodynamic polarization tests (ParStat 2273) based on ASTM Specifications G5 and G59. To determine the extent to which the alloys will contribute to galvanic corrosion in a marine environment (3.5 wt% NaCl), corrosion analysis software was used to produce fitted Tafel lines to determine the open circuit potential, Voc, for each alloy. The Voc values for the alloys were found to be -66.58 mV for Gold ABA, 13.01 mV for Nicoro®, -39.00 mV for Nioro®, 23.4 mV …


Manufacture And Mechanical Testing Of Thin Film Composites Composed Of Poly-Lactic Acid And Nanocrystalline Cellulose, Catherine E. Mohan Jun 2014

Manufacture And Mechanical Testing Of Thin Film Composites Composed Of Poly-Lactic Acid And Nanocrystalline Cellulose, Catherine E. Mohan

Materials Engineering

Society’s overuse of petroleum-based plastic products has created a waste problem that is threatening environments around the world. New efforts have been made to find a suitable replacement derived from a renewable source. Poly-lactic acid has become one of the front-runners in this search. It is derived from starches found in potatoes, corn, and other grains. There are many factors that make Poly-lactic acid-based polymers a suitable replacement for petroleum-based ones, but it still suffers from low mechanical strength due to low crystallinity percentages. Doping the polymer with nanocrystalline cellulose provides more nucleation sites for the crystallization of the polymer …


An Intercritical Heat Treatment Study Of High Strength, Microalloyed Ferrous Open Die Forgings, Kelly Elizabeth Stewart Jun 2014

An Intercritical Heat Treatment Study Of High Strength, Microalloyed Ferrous Open Die Forgings, Kelly Elizabeth Stewart

Materials Engineering

High strength, low alloy steel is most commonly utilized in plate or sheet form-with a thickness under 4 in, one unconventional application however, is open die forging where cross-sectional area can be as large as 9.5 in by 11.5 in. When forging to larger section size than one would thermo-mechanically roll sheet steel, a new set of complications, such as variation in microstructure and mechanical properties, arise. This study investigates the heat treatment and processing options needed to negate the inherent microstructural irregularity and Charpy V-Notch (CVN) toughness variation. Intercritical heat treatment—normalizing and then quench and tempering above the A …


Revealing Prior Austenite Grain Boundaries Of 4340 Steel, Ryan Brierly Barrows Jun 2014

Revealing Prior Austenite Grain Boundaries Of 4340 Steel, Ryan Brierly Barrows

Materials Engineering

Grain growth during austenitization has a negative effect on fatigue strength. Several methods have been investigated in order to determine an accurate method of measuring the austenite grain size of 4340 steel. The McQuaid-Ehn method, an industry standard for evaluating austenite grain size, has been recognized to produce inaccurate results due to the coarsening of grains during extended austenitizing. A method utilized for hypoeutectoid steels, outlined by the ASTM-E112 standard, is investigated to potentially obtain more accurate results by reducing the duration of austenitizing. Studies regarding effective etching procedures for revealing austenite grains without austenitizing are also addressed. Samples are …


High Cycle Rotating Bending Fatigue Of 6061-T6 Friction Stir Welded Extrusions, John Chang, Travis Miller Jun 2014

High Cycle Rotating Bending Fatigue Of 6061-T6 Friction Stir Welded Extrusions, John Chang, Travis Miller

Materials Engineering

Fatigue testing was done on friction stir welded joints of 6061-T6 aluminum extrusions. Tests were run using a rotating bending fatigue machine at stresses from 111.5 to 138.7 MPa. Failures occurred on the order of 105 to 107 cycles, and an S-N curve was generated based off of the failure results. After the samples failed, the location of the failure and the number of cycles to failure were noted. Fatigue samples were designed in SolidWorks with a tapered 2 inch reduced section. The 2 inch reduced section will include the entire weld region as seen from the microhardness …


Relationship Between Bagging Methods And Pre-Weld Holding Times On Porosity Formation In 2219 Aluminum Ac-Tig Welds, Mariah Grace Head, Tyson Daniel Mobley Jun 2014

Relationship Between Bagging Methods And Pre-Weld Holding Times On Porosity Formation In 2219 Aluminum Ac-Tig Welds, Mariah Grace Head, Tyson Daniel Mobley

Materials Engineering

The purpose of this study was to determine relationships between bagging methods and pre-weld holding times on the formation of porosity when AC-TIG welding 2219 aluminum. Considering the strict guidelines and specifications required within the aerospace industry, maintaining quality welds is of paramount importance to control part integrity for aerospace applications. This project focused on two parameters involved in the preparation of aluminum parts for welding: bagging method and pre-weld holding time. Welding geometry was simplified to bead-on plate instead of the standard joint welds. Radiographic analysis of the samples showed that all levels of both parameters produced “passing welds.” …