Effect Of Zr Additions On Thermal Stability Of Al-Cu Precipitates In As-Cast And Cold Worked Samples,
2018
Michigan Technological University
Effect Of Zr Additions On Thermal Stability Of Al-Cu Precipitates In As-Cast And Cold Worked Samples, Kyle Deane, Paul G. Sanders
Michigan Tech Publications, Part 1
While Zr is frequently added to Al alloys to control grain size with the formation of large (>1 μm) primary precipitates, little research has been conducted on the effect of nanoscale Al3Zr precipitates on Al alloys. By comparing the precipitation and corresponding strength evolution between Al-Cu-Zr alloys with different Zr concentrations, the effects of Zr on Al-Cu precipitation with and without primary Al3Zr precipitates can be observed. In the absence of these large precipitates, all Al3Zr phases can be formed, through high temperature aging treatments, as a dispersion of nanoprecipaites inside the Al …
Design And Synthesis Of Novel Nanometallic Catalysts And Electrode Materials For Green Fuel Cells,
2018
Binghamton University--SUNY
Design And Synthesis Of Novel Nanometallic Catalysts And Electrode Materials For Green Fuel Cells, Jing Zhang
Graduate Dissertations and Theses
The United Nations formally adopted 17 sustainable development goals (SDGs) at its 2015 summit. Many of these goals addressed issues such poverty, hunger, health, education, climate-change, gender equality, water, sanitation, energy, urbanization, environment and social justice. The seventh SDG seeks to ensure access to affordable, reliable, sustainable and modern energy for all. So among all renewable forms of energy, fuel cells with high efficiency have attracted a lot of attention recently. In particular, the direct ethanol fuel cells (DEFCs) and microbial fuel cells (MFCs) are significant due to their green fuel, less waste generated and environmental friendliness. Hence the overall …
Aligned Carbon Nanotube Arrays Bonded To Solid Graphite Substrates: Thermal Analysis For Future Device Cooling Applications,
2018
Wright State University - Main Campus
Aligned Carbon Nanotube Arrays Bonded To Solid Graphite Substrates: Thermal Analysis For Future Device Cooling Applications, Betty T. Quinton, Levi Elston, James D. Scofield, Sharmila M. Mukhopadhyay
Mechanical and Materials Engineering Faculty Publications
Carbon nanotubes (CNTs) are known for high thermal conductivity and have potential use as nano-radiators or heat exchangers. This paper focuses on the thermal performance of carpet-like arrays of vertically aligned CNTs on solid graphite substrates with the idea of investigating their behavior as a function of carpet dimensions and predicting their performance as thermal interface material (TIM) for electronic device cooling. Vertically aligned CNTs were grown on highly oriented pyrolytic graphite (HOPG) substrate, which creates a robust and durable all-carbon hierarchical structure. The multi-layer thermal analysis approach using Netzsch laser flash analysis system was used to evaluate their performance …
Investigation Of The Use Of A Bio-Derived Solvent For Non-Solvent-Induced Phase Separation (Nips) Fabrication Of Polysulfone Membranes,
2018
University of Kentucky
Investigation Of The Use Of A Bio-Derived Solvent For Non-Solvent-Induced Phase Separation (Nips) Fabrication Of Polysulfone Membranes, Xiaobo Dong, Amna Al-Jumaily, Isabel Escobar
Chemical and Materials Engineering Faculty Publications
Organic solvents, such as N-methyl-2-pyrrolidone (NMP) and dimethylacetamide (DMAc), have been traditionally used to fabricate polymeric membranes. These solvents may have a negative impact on the environment and human health; therefore, using renewable solvents derived from biomass is of great interest to make membrane fabrication sustainable. Methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate (Rhodiasolv PolarClean) is a bio-derived, biodegradable, nonflammable and nonvolatile solvent. Polysulfone is a commonly used polymer to fabricate membranes due to its thermal stability, strong mechanical strength and good chemical resistance. From cloud point curves, PolarClean showed potential to be a solvent for polysulfone. Membranes prepared with PolarClean were investigated in terms of …
Research And Development Of Powder Brazing Filler Metals For Diamond Tools: A Review,
2018
Harbin Institute of Technology, China
Research And Development Of Powder Brazing Filler Metals For Diamond Tools: A Review, Fei Long, Peng He, Dusan P. Sekulic
Mechanical Engineering Faculty Publications
Powder brazing filler metals (PBFMs) feature a number of comparative advantages. Among others, these include a low energy consumption, an accurate dosage, a good brazeability, a short production time, and a high production efficiency. These filler metals have been used in the aerospace, automobile, and electric appliances industries. The PBFMs are especially suitable for diamond tools bonding, which involves complex workpiece shapes and requires accurate dosage. The recent research of PBFMs for diamond tools is reviewed in this paper. The current applications are discussed. The CuSnTi and Ni-Cr-based PBFMs have been the two commonly used monolayer PBFMs. Thus, the bonding …
Analysis Of Surface Integrity In Machining Of Aisi 304 Stainless Steel Under Various Cooling And Cutting Conditions,
2018
RWTH Aachen University, Germany
Analysis Of Surface Integrity In Machining Of Aisi 304 Stainless Steel Under Various Cooling And Cutting Conditions, F. Klocke, B. Döbbeler, S. Lung, S. Seelbach, Ibrahim S. Jawahir
Institute for Sustainable Manufacturing Faculty Publications
Recent studies have shown that machining under specific cooling and cutting conditions can be used to induce a nanocrystalline surface layer in the workspiece. This layer has beneficial properties, such as improved fatigue strength, wear resistance and tribological behavior. In machining, a promising approach for achieving grain refinement in the surface layer is the application of cryogenic cooling. The aim is to use the last step of the machining operation to induce the desired surface quality to save time-consuming and expensive post machining surface treatments. The material used in this study was AISI 304 stainless steel. This austenitic steel suffers …
Reprapable Recyclebot: Open Source 3-D Printable Extruder For Converting Plastic To 3-D Printing Filament,
2018
Michigan Technological University
Reprapable Recyclebot: Open Source 3-D Printable Extruder For Converting Plastic To 3-D Printing Filament, Aubrey Woern, Joseph Mccaslin, Adam Pringle, Joshua M. Pearce
Department of Materials Science and Engineering Publications
In order to assist researchers explore the full potential of distributed recycling of post-consumer polymer waste, this article describes a recyclebot, which is a waste plastic extruder capable of making commercial quality 3-D printing filament. The device design takes advantage of both the open source hardware methodology and the paradigm developed by the open source self-replicating rapid prototyper (RepRap) 3-D printer community. Specifically, this paper describes the design, fabrication and operation of a RepRapable Recyclebot, which refers to the Recyclebot’s ability to provide the filament needed to largely replicate the parts for the Recyclebot on any type of RepRap 3-D …
Effects Of Tension On Resonant Frequencies Of Strings,
2018
Linfield College
Effects Of Tension On Resonant Frequencies Of Strings, Blake Burnett
Senior Theses
This project tests and explores resonance of strings. Since all materials and mechanisms are affected by vibrations, it is important to know the frequencies at which resonance occurs. To explore this subject, strings were used as a model material to test the effect tension has on resonance. The fundamental frequencies and the corresponding modes of resonance were used to analyze the data. The results of this experiment show that increasing tension on a string increases its resonance frequency. Understanding the physics behind resonance frequency allows systems to be designed to take advantage of resonance properties, or to avoid resonance where …
Measuring The Double Layer Capacitance Of Electrolyte Solutions Using A Graphene Field Effect Transistor,
2018
Linfield College
Measuring The Double Layer Capacitance Of Electrolyte Solutions Using A Graphene Field Effect Transistor, Agatha Ulibarri
Senior Theses
When operating graphene field effect transistors (GFETs) in fluid, a double layer capacitance (Cdl) is formed at the surface. In the literature, the Cdl is estimated using values obtained using metal electrode experiments. Due to the distinctive electronic and surface properties of graphene, there is reason to believe these estimates are inadequate. This work seeks to directly characterize the double layer capacitance of a GFET. A unique method for determining the Cdl has been implemented, and data has been obtained for three electrolytes and one ionic fluid. The results yield dramatically lower Cdl values than …
Mesoscale Computational Studies Of Thin-Film Bijels,
2018
University of Arkansas, Fayetteville
Mesoscale Computational Studies Of Thin-Film Bijels, Joseph M. Carmack
Graduate Theses and Dissertations
Bijels are a relatively new class of soft materials that have many potential applications in the technology areas of energy, medicine, and environmental sustainability. They are formed by the arrest of binary liquid spinodal decomposition by a dispersion of solid colloidal nanoparticles. This dissertation presents an in-depth simulation study of Bijels constrained to thin-film geometries and in the presence of electric fields. We validate the computational model by comparing simulation results with previous computational modeling and experimental research. In the absence of suspended particles, we demonstrate that the model accurately captures the rich kinetics associated with diffusion-based surface-directed spinodal decomposition. …
Effects Of Surface-Directed Spinodal Decomposition On Binary Thin-Film Morphology,
2018
University of Arkansas, Fayetteville
Effects Of Surface-Directed Spinodal Decomposition On Binary Thin-Film Morphology, Michael Brian Wise
Graduate Theses and Dissertations
Preferential wetting can have a significant impact on the kinetics of phase separation in certain systems. The depletion of the wetting component can simply alter domain growth rates or change the structure entirely. In this thesis, we employ a Cahn-Hilliard model to study the evolution of binary thin-films with symmetric surface wetting. Three possible morphologies were identified: discrete, bicontinuous, and a novel quasi-2D bicontinuous structure in which both phases retain continuity throughout the volume as well as on the center xy plane. Using a continuity factor, regions of film thickness versus blend composition were classified as producing a certain morphology. …
Thermoelectrics And Thermoelectric Devices,
2018
Linfield College
Thermoelectrics And Thermoelectric Devices, Benjamin T. Erck
Senior Theses
The field of thermoelectrics has many applications, and more are found in everyday systems. From its current studies, it is apparent that improving the figure of merit zT (which defines a good thermoelectric material) is important in the effectiveness of power generation. Another important part of thermoelectrics is the duality of these devices. They can both move heat and generate power, depending on their role in the system. In this thesis research, a process was made to test these thermoelectric relationships for a few Peltier devices in order to understand their efficiencies and what systems they can be applied to.
Fabrication Of Solid Polymeric 3d Shapes From Programmable Flat Hydrogel Sheets,
2018
University of Texas at Arlington
Fabrication Of Solid Polymeric 3d Shapes From Programmable Flat Hydrogel Sheets, Ninad Vilas Khadse
Material Science and Engineering Theses - Archive
Modern methods of fabricating three-dimensional (3D) objects include sheet metal forming, thermoforming, and additive manufacturing among others. These methods have their own advantages and disadvantages regarding scalability, customizability, and time efficiency. A promising approach is to program the growth (expansion and contraction) of hydrogel sheets to form 3D structures. The differential growth-induced 3D shaping approach has the advantages of traditional manufacturing (scalability) and additive manufacturing (customizability). The objective of this study is to create nanocomposite 3D structures that are stable in ambient environment using the growth-induced 3D shaping approach. This study determines the effect of silica nanoparticles in hydrogels on …
Characterization Of Normal And Abnormal Bones By Raman Spectroscopy : Analysis Of Mineral To Matrix Ratio Of Bone Using Advanced Materials Characterization Techniques,
2018
University of Texas at Arlington
Characterization Of Normal And Abnormal Bones By Raman Spectroscopy : Analysis Of Mineral To Matrix Ratio Of Bone Using Advanced Materials Characterization Techniques, Meet Yagnesh Shah
Material Science and Engineering Theses - Archive
Bone disorders and disease are associated with multiple factors. Some of the disorders and diseases are difficult to understand because of their unknown root causes. Our goal was to differentiate between normal and genetically modified rat bone groups by finding the difference in mineral to matrix (Mn/Mx) content using Raman spectroscopy. Raman spectroscopy gives the chemical composition based on the vibration modes of the molecules. Quantitative analysis of Mn/Mx content calculated from Raman spectra allowed us to distinguish between healthy and genetically modified rat bone groups. We have presented the results by averaging the Mn/Mx ratios. Thus, the most significant …
Quantitative Analysis Of Mineral/Matrix To Evaluate Genetically Altered Bone With Infrared Spectroscopy And X-Ray Spectral Imaging,
2018
University of Texas at Arlington
Quantitative Analysis Of Mineral/Matrix To Evaluate Genetically Altered Bone With Infrared Spectroscopy And X-Ray Spectral Imaging, Sunil Balasaheb Yadav
Material Science and Engineering Theses - Archive
This thesis focuses on the characterization of bone with the help of Fourier Transform Infrared Spectroscopy and Energy Dispersive Spectroscopy. Such analysis of the physics and chemistry of biomaterials is vital to resolve problems in life science of bone-related diseases and disorders. Material characterization can help in the understanding of disease mechanisms and lead to useful drugs and other treatments. In this thesis, I have used bone materials produced by groundbreaking research at UT Southwestern Research Center and Texas Scottish Rite Children's Hospital to establish that idiopathic clubfoot (Talipes equinovarus) is associated with the Follistatin 5 gene. We studied healthy …
Study Of Copper-Rich Intermetallic Phase Formation In Copper-Aluminum Binary System,
2018
University of Texas at Arlington
Study Of Copper-Rich Intermetallic Phase Formation In Copper-Aluminum Binary System, Valery Georges Ouvarov-Bancalero
Material Science and Engineering Dissertations - Archive
This work aims to study the initial formation and subsequent growth of intermetallic compounds (IMC) in the binary Al-Cu system. Al-Cu pair configurations have been successfully used for several decades as structural components, and extensive research on their mechanical and metallurgical properties is available. More recently, the microelectronics industry started implementing the Cu wire-bond technology, which renewed the interest of the scientific community. As with every technological evolution, initial quality and reliability issues arose. Copper (Cu) wire to aluminum (Al) bond-pad is prone to crack nucleation leading to failure at the interface between Cu and Cu-rich IMCs. Even though numerous …
Accelerated Creative Problem Solving And Product Improvement Applied To Experimental Devices In A Bloodstain Pattern Interpretation Class--Improving The Role Of Insight Development Tools As A Generator Of New Ideas In Novel Situations,
2018
SUNY Buffalo State University
Accelerated Creative Problem Solving And Product Improvement Applied To Experimental Devices In A Bloodstain Pattern Interpretation Class--Improving The Role Of Insight Development Tools As A Generator Of New Ideas In Novel Situations, Douglas Ridolfi
Creativity and Change Leadership Graduate Student Master's Projects
This project uses an action research centered study protocol to examine the effects of a problem-based learning exercise related to bloodstain pattern interpretation in a crime scene processing and general criminalistics class taught as part of an upper division forensic chemistry major in a four year college. The goal is to apply design principles and creative problem solving methods directly adapted to a project involving interpreting a set of crime scene photographs depicting blood spatter and with the aid of guided exercises in ideation and design, lead students into the development of alternate theories of how the bloodstains were created …
Phase Field Model Of Thermally Induced Phase Separation (Tips) For The Formation Of Porous Polymer Membranes,
2018
University of Arkansas, Fayetteville
Phase Field Model Of Thermally Induced Phase Separation (Tips) For The Formation Of Porous Polymer Membranes, Ashley Green, Aria Green
Mechanical Engineering Undergraduate Honors Theses
Most membrane research and development has been done through experimental work, which can be costly and time consuming. An accurate computational model would greatly reduce the need for these experiments. The focus of the research presented in this paper is to create an accurate computational model for membrane formation using thermally induced phase separation (TIPS). A phase field model is employed to create this model including the Cahn Hilliard Equation and Flory Huggins Theory. This model produced computational results that correspond well with theoretical and experimental results. The model was then adapted to correspond to the PVDF/DPC polymer-solvent system by …
Influence Of Impact Conditions On Feedstock Deposition Behavior Of Cold-Sprayed Fe-Based Metallic Glass,
2018
Bucknell University
Influence Of Impact Conditions On Feedstock Deposition Behavior Of Cold-Sprayed Fe-Based Metallic Glass, Constance Ziemian, Wendelin Wright, David E. Cipoletti
Faculty Journal Articles
Cold spray is a promising method by which to deposit dense Fe-based metallic glass coatings on conventional metal substrates. Relatively low process temperatures offer the potential to prevent the crystallization of amorphous feedstock powders while still providing adequate particle softening for bonding and coating formation. In this study, Fe48 Mo14 Cr15 Y2 C15 B6 powder was sprayed onto a mild steel substrate, using a variety of process conditions, to investigate the feasibility of forming well-bonded amorphous Fe-based coatings. Particle splat adhesion was examined relative to impact conditions, and the limiting values of temperature and velocity associated with successful softening and …
Aerospace Mission Outcome: Predictive Modeling,
2018
Portland State University
Aerospace Mission Outcome: Predictive Modeling, Ephraim Suhir
Mechanical and Materials Engineering Faculty Publications and Presentations
Human-in-the-Loop (HITL)-related models can be applied in various aerospace vehicular problems, when human qualifications and performance are crucial and the ability to quantify them is therefore imperative; since nobody is perfect, these evaluations should preferably be done on a probabilistic basis. The suggested models can also be used in many other areas of applied science and engineering, not even necessarily vehicular engineering, when a human encounters an extraordinary situation and should possess a sufficiently high human capacity factor (HCF) to successfully cope with an elevated mental workload (MWL). The incentive for probabilistic predictive modeling and the rationale for such modeling …
