Controllable Internal Mixing In Coalescing Droplets Induced By The Solutal Marangoni Convection Of Surfactants With Distinct Headgroup Architectures,
2018
Purdue University
Controllable Internal Mixing In Coalescing Droplets Induced By The Solutal Marangoni Convection Of Surfactants With Distinct Headgroup Architectures, Jerome J. Nash, Patrick T. Spicer, Kendra Erk
School of Materials Engineering Faculty Publications
Through several complementary experiments, an investigation of the bulk and interfacial flows that emerged during the coalescence of two water-in-oil droplets with asymmetric compositional properties was performed. By adding surfactant to one of the coalescing droplets and leaving the other surfactant-free, a strong interfacial tension gradient (i.e., solutal Marangoni) driving energy between the merging droplets generated pronounced internal mixing. The contributions of two distinct types of surfactant, anionic ammonium lauryl sulfate (ALS) and cationic cetyltrimethylammonium bromide (CTAB) on the rate of coalescence bridge expansion and on the generation of opposing flows during coalescence were investigated. All coalescence experiments supported the …
Preparation And Characterization Of Eva/Cort Microparticles For Rattlesnake Endocrinology Studies,
2018
California Polytechnic State University, San Luis Obispo
Preparation And Characterization Of Eva/Cort Microparticles For Rattlesnake Endocrinology Studies, Alexander C. Pauer
Materials Engineering
No abstract provided.
In Situ Sem Solidification Study Of Ga And Egain: A Characterization Technique For Monitoring The Microstructural Evolution Of Liquid Metals,
2018
California Polytechnic State University, San Luis Obispo
In Situ Sem Solidification Study Of Ga And Egain: A Characterization Technique For Monitoring The Microstructural Evolution Of Liquid Metals, Jeremy Geovann Del Aguila
Materials Engineering
Scanning electron microscopy (SEM) video recording is used to characterize the solidification of small volumes of 99.999% pure gallium (Ga) and eutectic gallium-indium (eGaIn) under a high vacuum environment. Specimen are superheated to 55℃ using a hot plate, cast into spherical droplets, and cooled in situ by means of a Peltier cooling stage. Special attention is given to the preparation of the specimen prior to viewing because of gallium and its alloys’ nature to form an oxide layer when melted and air cooled. The oxide acts as a skin that inhibits the observation of microstructural features during solidification. Heated samples …
An Evaluation Of Ultrasonic Shot Peening And Abrasive Flow Machining As Surface Finishing Processes For Selective Laser Melted 316l,
2018
California Polytechnic State University, San Luis Obispo
An Evaluation Of Ultrasonic Shot Peening And Abrasive Flow Machining As Surface Finishing Processes For Selective Laser Melted 316l, Rhys Gilmore
Master's Theses
Additive Manufacturing, and specifically powder bed fusion processes, have advanced rapidly in recent years. Selective Laser Melting in particular has been adopted in a variety of industries from biomedical to aerospace because of its capability to produce complex components with numerous alloys, including stainless steels, nickel superalloys, and titanium alloys. Post-processing is required to treat or solve metallurgical issues such as porosity, residual stresses, and surface roughness. Because of the geometric complexity of SLM produced parts, the reduction of surface roughness with conventional processing has proven especially challenging. In this Thesis, two processes, abrasive flow machining and ultrasonic shot peening, …
Temper Response Of A Vanadium Microalloy Steel,
2018
California Polytechnic State University, San Luis Obispo
Temper Response Of A Vanadium Microalloy Steel, Bradley W. Hostetler
Materials Engineering
This investigation details the effect of a quench-and-temper processing treatment on the mechanical properties of a microalloy steel being considered for use as a pipeline flange. Microalloy steels are normally processed via Thermo-Mechanically Controlled Processing (TMCP) due to the increased strength from ferrite grain refinement; however, the geometry of a pipeline flange requires post processing beyond TMCP which diminishes the strengthening effect provided by TMCP. The purpose of this research project is to determine the mechanical properties produced when a vanadium microalloy steel is quenched and tempered. The two major considerations are the effect of tempering time on properties and …
Phase Change Materials For Thermal Management Of Kennedy Library Study Rooms,
2018
California Polytechnic State University, San Luis Obispo
Phase Change Materials For Thermal Management Of Kennedy Library Study Rooms, Colin J. Empey
Materials Engineering
The overall purpose of this study was to find a phase change material (PCM) or a combination of PCMs as a thermal management solution for the fifth-floor study rooms in Kennedy Library. First and foremost, the PCM must take in heat to change phase. A PCM would be a better candidate the more heat it needs to change phase. To quantify this, the team utilized a DSC to find how much energy each candidate PCM required to change phase. Coconut oil, palm oil, and white chocolate were found to have the best ability to absorb heat. Secondly, the PCM should …
Anomalous 304 Stainless Steel Mechanical Properties In Medical Guide Wires,
2018
California Polytechnic State University, San Luis Obispo
Anomalous 304 Stainless Steel Mechanical Properties In Medical Guide Wires, Andrew Joseph Freeman
Materials Engineering
Stainless steel medical guide wire cores, processed by Abbott Vascular, are returning anomalous mechanical properties upon strain hardening and heat treatment. As theory dictates, mechanical strength properties increase with strain hardening, and decrease with an annealing treatment. The opposite response is being observed. This is counter intuitive to fundamental materials knowledge, and a perfect materials engineering paradox. This project was designed to characterize these behaviors, and attempt to determine causation. To accomplish this, tensile testing of all processing steps mapped the mechanical property evolution of the wire. Published literature research revealed the potential of nitrogen and chromium solid state diffusion …
Solar Cell Potential Induced Degradation Sensor,
2018
California Polytechnic State University, San Luis Obispo
Solar Cell Potential Induced Degradation Sensor, Luc Alexandre Tousignant
Materials Engineering
It is important to maintain Photovoltaic (PV) cells and protect them from damage mechanisms like Potential Induced Degradation (PID), which can contribute to shorter lifespans and lower efficiencies. Current leakage through cell encapsulation can cause charge migration in PV cells that reduces the maximum quantum efficiency, which is the cause of PID. An experiment was setup to determine the feasibility of a non-silicon sensor able to produce similar leakage behavior to traditional PV cells under recorded humidity conditions. Thin sheet metals were encapsulated in EVA, a common PV encapsulant polymer, and mounted in aluminum framing. Three sensors, along with a …
Effects Of Head Formation And Heat Treatment On The Mechanical Properties Of Connecting Rod Bolts,
2018
California Polytechnic State University, San Luis Obispo
Effects Of Head Formation And Heat Treatment On The Mechanical Properties Of Connecting Rod Bolts, Caleb A. Leavitt, Matthew R. Lauretta
Materials Engineering
Oliver Racing Parts (ORP; Charlevoix, Michigan) is looking to optimize their manufacturing process for high-strength connecting rod bolts. A high yield strength is desired for the bolts because deformation would result in catastrophic engine failure. The bolts were made of H11, a chromium hot-work tool steel; and MLX17, a precipitation hardenable stainless steel. Tensile testing was performed to determine the tensile and yield strengths of the bolts. Fracture surfaces were imaged via scanning electron microscopy to characterize the failure modes. To observe the effects of bolt heading on microstructure and bolt strength, two batches of MLX17 were prepared; one batch …
Development Of Low Cost, Environmentally Friendly And High Strength Carbon Foams From Bread And Cake,
2018
California Polytechnic State University, San Luis Obispo
Development Of Low Cost, Environmentally Friendly And High Strength Carbon Foams From Bread And Cake, Laura Mountain-Tuller
Materials Engineering
Carbon foam is a high niche material that consists of a highly porous, three-dimensional cellular network that is characterized by extremely high strength-to-weight ratios and low thermal conductivity. Due to these properties, carbon foams excel in structural and thermal applications, especially in the aerospace industry. Typically, carbon foams are formed through a heating process called pyrolysis of polymer precursors with high carbon content. This process is done at high temperatures in an oxygen free environment. These precursors are expensive to make and use toxic chemicals to produce, therefore, there is a push to find an environmentally friendly and cost-effective method …
Composite Suspension For A Mass Market Vehicle,
2018
California Polytechnic State University, San Luis Obispo
Composite Suspension For A Mass Market Vehicle, Sarah M. Chapiama, Brian Auyeung, Jose Guerrero, Ethan Lau
Mechanical Engineering
Statement of Confidentiality: The complete senior project report was submitted to the project advisor and sponsor. The results of this project are of a confidential nature and will not be published at this time.
The Effects Of Varying Composition And Build Direction On Direct Metal Deposition Fabricated Inconel 718,
2018
California Polytechnic State University, San Luis Obispo
The Effects Of Varying Composition And Build Direction On Direct Metal Deposition Fabricated Inconel 718, Abigail P. Nilan, Jessica M. Fordham
Materials Engineering
Inconel 718 (IN718) is a popular wrought superalloy, and is currently being investigated for additive manufacturing (AM) applications in the aerospace industry. However, overaging and the presence of microcracks have caused a significant reduction in properties. The purpose of this study is to meet or exceed the mechanical properties of wrought IN718 by varying the composition and build direction of the AM alloy. Alternative compositions were selected with Oerlilon Metco’s Rapid Alloy Development (RAD) software, and differ in niobium content, which increases the fraction of the primary strengthening phase (γʺ). Direct metal deposition (DMD) was used to fabricate the samples, …
Development Of Test Methods For Measuring Fiber Misalignment And Warping In Honeycomb-Core Composite Panels,
2018
California Polytechnic State University, San Luis Obispo
Development Of Test Methods For Measuring Fiber Misalignment And Warping In Honeycomb-Core Composite Panels, Wyatt Taylor, Haripriya Nilakantan
Materials Engineering
Zodiac Aerospace manufactures honeycomb-core composite panels to be used in aircraft cabin interior components. During the manufacturing process, some panels become warped such that they cannot be used for their designated aircraft cabin components. As a result, these panels are scrapped because they cannot be recycled. About 44 to 90% of panels become warped during manufacturing. Warping is caused by many factors, including layer misalignment, processing parameters such as temperature and pressure gradients, and fiber misalignment in the prepregs. Currently, Zodiac does not have any data on the effect of fiber misalignment on panel warpage, so a testing protocol was …
Synthesis Of Ɣ-Cyclodextrin Metal Organic Frameworks And The Encapsulation Of Caffeine And Theophylline,
2018
California Polytechnic State University, San Luis Obispo
Synthesis Of Ɣ-Cyclodextrin Metal Organic Frameworks And The Encapsulation Of Caffeine And Theophylline, Evan Noel Sommerville, Riley Andrew Harden
Materials Engineering
Nanoporous, non-toxic, ɣ-cyclodextrin metal organic frameworks (𝛾-CDMOFs) have potential applications in fields such as drug delivery and organic compound storage. The properties of many methylxanthines (alkaloids such as caffeine and theophylline) could be improved through 𝛾-CDMOF encapsulation, yet little research has been performed on the subject. In this study, 𝛾-CDMOFs were synthesized in order to 1. Determine if the vapor diffusion synthesis method can produce 𝛾-CDMOF crystals that replicate those in literature and 2. Determine if 𝛾-CDMOFs are able to encapsulate methylxanthines. The 𝛾-CDMOFs were synthesized through vapor diffusion of methanol in a solution of ɣ-cyclodextrin and potassium hydroxide (KOH). …
Next Generation Protocol: Innovating A Resilient Future,
2018
California Polytechnic State University, San Luis Obispo
Next Generation Protocol: Innovating A Resilient Future, Andrew Steven Rudnick, Jamie Cannady, Joe Decesaro, Juan A. Ortiz Salazar
Materials Engineering
Conventional practices do not account for product life beyond end-of-sale – these practices are not sustainable. We have developed an end-of-life protocol that includes a metric that we call the Recovery Rating. The objectives of this Next Generation Protocol, beyond supporting the United Nations’ Sustainable Development Goals, are to encourage the production of goods designed for recovery and to promote the collaboration between consumers, the public, and the private sector to recover goods at their end-of-life. The Recovery Rating that we propose evaluates and quantifies recovery potential of products. The Recovery Rating, which is normed against embodied energy from the …
Investigation Of Narloy-Z Yield Strength In Response To Changes In Ingot Processing And Heat Treatment,
2018
California Polytechnic State University, San Luis Obispo
Investigation Of Narloy-Z Yield Strength In Response To Changes In Ingot Processing And Heat Treatment, Stanley C. Goto, Sarah E. Wattenberg
Materials Engineering
This study investigates the effect of cooling rate on the yield strength of NARloy-Z. NARloy-Z is a copper-based alloy with 3 wt.% silver and 0.5 wt.% zirconium. The types of NARloy-Z were classified by the ingot processing (old or new) and the material lot (old or new). There were three variations of NARloy-Z in this study: old processing and material (Old/Old); old processing and new material (Old/New); and new processing and material (New/New). NARloy-Z undergoes a braze thermal cycle and age (BTCA) heat treatment for its application, and a single cooling rate within the BTCA was manipulated in this study. …
Mechanical Characterization Of Selectively Laser Melted 316l Stainless Steel Body Centered Cubic Unit Cells And Lattice Of Varying Node Radii And Strut Angle,
2018
California Polytechnic State University, San Luis Obispo
Mechanical Characterization Of Selectively Laser Melted 316l Stainless Steel Body Centered Cubic Unit Cells And Lattice Of Varying Node Radii And Strut Angle, Christopher James Hornbeak
Master's Theses
An experimental study of several variants of radius and strut angle of the body centered cubic unit cell was performed to determine the mechanical properties and failure mechanisms of the mesostructure. Quasi static compression tests were performed on an Instron® universal testing machine with a 50kN load cell at 0.2mm/min. The test samples were built using a SLM Solutions 125 selective laser melting machine with 316L stainless steel. Test specimens were based on 5mm cubic unit cells, with a strut diameter 10% of the unit cell size, with skins on top and bottom to provide a cantilever boundary constraint. Specimens …
Evaluation Of Electrochemical And Laser Polishing Of Selectively Lasermelted 316l Stainless Steel,
2018
California Polytechnic State University, San Luis Obispo
Evaluation Of Electrochemical And Laser Polishing Of Selectively Lasermelted 316l Stainless Steel, Julian R. Lohser
Master's Theses
Selective laser melting has shown incredible growth as a metallic additive manufacturing process in recent years. While it does provide many solutions and new ways to approach challenges, it does not come without issues of its own, namely, surface roughness. In the as-printed state, the surface roughness of selectively laser melted parts is unacceptable for use in engineering applications. Additionally, selective laser melting is used to produce complex geometries with hard to reach features, preventing conventional mechanical polishing from being successful. Therefore, it is necessary to evaluate non-mechanical polishing processes as treatments for surface roughness. In this study, electrochemical and …
A National Pragmatic Safety Limit For Nuclear Weapon Quantities,
2018
Michigan Technological University
A National Pragmatic Safety Limit For Nuclear Weapon Quantities, Joshua M. Pearce, David C. Denkenberger
Department of Materials Science and Engineering Publications
This study determines the nuclear pragmatic limit where the direct physical negative consequences of nuclear weapons use are counter to national interests, by assuming all unknowns are conservatively optimistic. The only effect considered is nuclear winter (“nuclear autumn” in the low weapons limits) and the resultant effects on the aggressor nation. First, the ability of low nuclear weapon limits is probed for maintaining deterrence in the worst-case scenario of attacking the most-populous nation. Second, the ability of aggressor nations to feed themselves is assessed without trade and industry resultant from a nuclear attack causing “nuclear autumn” (10% global agricultural shortfall). …
Mass Accretion And Ozone Reactivity Of Idealized Indoor Surfaces In Mechanically Or Naturally Ventilated Indoor Environments,
2018
Portland State University
Mass Accretion And Ozone Reactivity Of Idealized Indoor Surfaces In Mechanically Or Naturally Ventilated Indoor Environments, Elliott T. Gall, Donghyun Rim
Mechanical and Materials Engineering Faculty Publications and Presentations
In indoor environments, accretion of mass to materials may provide sites for surface chemistry that differ from those of the original material. Since indoor surfaces are a major sink of oxidant gases, surface mass accretion may impact indoor O3 chemistry. In this study, the effect of surface mass accretion on O3 surface deposition was tested by deploying cleaned borosilicate glass plates in two types of indoor environments: a mechanically ventilated ( MV ) office and a naturally ventilated ( NV ) residence located in Singapore. In each environment, seven replicate glass plates and one field blank were deployed …
