Other Materials Science and Engineering Commons^™

Thermally Driven Spin Transport In Ferromagnetic Metals, Wafa Saud Aljuaid

Electronic Theses and Dissertations

Since the discovery in 2008, the spin Seebeck effect has become one of the most active topics in the spin caloritronics research field. It opened a new way to create spin current by a combination of magnetic fields and heat. A temperature gradient in ferromagnetic (FM) metals generates a ow of spin current due to split of spin chemical potential between spin up and spin down electrons. This thermal spin current has been detected using an attached nonmagnetic heavy metal with large spin Hall angle via the inverse spin hall effect (ISHE). A voltage signal is generated since the nonmagnetic …

Organophosphorus-Hydrazides As Potential Reactive Flame Retardants For Epoxy, Alexander B. Morgan, Vladimir Benin, Donald A. Klosterman, Abdulhamid Bin Sulayman, Mustafa Mukhtar, Mary L. Galaska

Chemical and Materials Engineering Faculty Publications

For structural composites used in vehicles and aircraft, flame retardant chemistries which enhance char formation and reduce heat release are preferred. Phosphorus-based and phosphorus–nitrogen flame retardants for epoxies have been well studied to date, but phosphorus hydrazides have not been studied for their flame-retardant potential in epoxy. These hydrazides offer some novel structures and they can potentially offer a combination of vapor and condensed phase flame retardant action. A series of eight compounds were systematically investigated in this study as reactive flame retardants in a bisphenol F epoxy/aliphatic amine resin system at a level of 2.5 wt% phosphorus. Results suggest …

Magnetism In Γ-Fesi2 Nanostructures: A First Principles Study, Sahil Dhoka

Dissertations, Master's Theses and Master's Reports

First-principles calculations are performed on γ-FeSi₂ nanostructures grown on Si (111) and (001) substrate. An attempt to explain the origin of emergent magnetic properties of the metastable gamma phase of iron di-silicide (γ-FeSi₂) is made, which show ferromagnetic behavior on nanoscale, unlike its possible bulk form. Many papers try to explain this magnetism from factors like bulk, epitaxial strain, interface, surface, edges, and corners but doesn’t provide an analytical study for these explanations. Density functional theory is used to analyze the magnetic effects of these factors. The results for the epitaxial structures show no magnetic behavior for …

Plasmon-Enhanced Optical Probes For Sensing Of Drug Metabolite, Jennifer Boryczka

Graduate Theses, Dissertations, and Problem Reports (ETD)

An Au@SiO₂ core-shell nanostar structure was synthesized along with CuInS2 quantum dots. The quantum dots display near-infrared fluorescence. In this work, the nanostar structure was functionalized with antibodies and then was utilized as a SERS probe for drug metabolite detection. Drugs are an illicit substance that police, medics, and hospitals need to know if an individual is under the influence of but that individual will not always be willing or able to provide that information. A sensor based on this new probe has been developed for detection of drug metabolites in buffer.

Chloride Effect In Fly Ash Geopolymer Cement, Evan Dimmick

Williams Honors College, Honors Research Projects

The production of ordinary portland cement (OPC) poses a significant impact on the world's carbon dioxide emissions through the wide global use of concrete. Geopolymer cements (GPC) made from alkali activated fly ash can serve as a replacement to OPCs, reducing the carbon dioxide emissions by as much as 80%. GPCs exhibit adequate or superior mechanical performance to OPCs. The corrosion of carbon steel rebar in concrete occurs largely from chloride ion attack. The focus of this project will be to experimentally determine the coefficient of diffusion for chloride ions in GPCs and OPCs and compare to the corrosion performance …

Jominy Hardenability Tester With In-Situ Heating, Luke Allen

Williams Honors College, Honors Research Projects

This project centers on building a Jominy Hardenability tester with In-Situ heating for the manufacturing lab at the University of Akron. A new process and setup will be designed using engineering concepts in order to make the testing more efficient and safer for the teaching and testing of metal hardness. The current Jominy testing setup has efficiency issues within the transfer of specimen from induction heater to testing rig. Our design will simplify the design by creating a test rig that removes the traveling aspect of the specimen which will limit the amount of premature cooling done and will be …

Effects Of Sensitization On Intergranular Boundaries Of Aluminum Alloy 5083, Kyle Balentine

Williams Honors College, Honors Research Projects

The purpose of this Honors Research Project is to show the effect of sensitization on intergranular corrosion (IGC) on AA5083. Sensitization is the process of a material to experience microstructural phase change, caused by thermal treatment, which promotes precipitation of secondary phases on the grain boundaries. The nitric acid mass loss test (NAMLT), SEM analysis, cyclic potentiodynamic polarization (CPP), and Electrochemical Impedance Spectroscopy (EIS) were performed to find a correlation to the degree of sensitization (DOS) and the pitting and IGC mechanisms. The DOS increased as heat treatment was applied. The SEM images displayed no clear precipitates on the grain …

Table Top Dome Tester, Travis Bernard, Sarah Kassinger, Amanda O'Reilly, Scott Salerno

Williams Honors College, Honors Research Projects

The Erichsen Cupping Test was used as a basis to design a dome tester. The intention of a dome tester is to test sheet metal material properties in all directions. This was done by clamping a piece of sheet metal and using a piston and hydraulic press to punch through the material. The force used to punch the material and the height of the deforming material can be gathered and the sheet metal properties can then be calculated. At the end of the project the team was able to successfully design and manufacture a hydraulic dome tester. However, due to …

Solvent-Free Coating Using Maco Bio-Based Reactive Diluent, Ryder James

Williams Honors College, Honors Research Projects

The project performed utilizes methacrylated cardanol (MACO) and a linseed oil resin to test how different weight percentages of MACO affect coating performance. MACO is synthesized from a phenolic lipid extracted from cashew nut shells, which are a cashew industry waste product. Not only does it utilize a waste product, but being a bio-based reactive diluent means it can replace the use of volatile organic solvents that are harmful to both humans and the environment. Weight percentage samples of 0%, 10%, 20%, 30%, and 40% were used. Coatings were applied using a 6-mil drawn down bar, with samples being prepared …

Tabletop Mechanical Tester, Jamie Dombroski, Brian English, Richard Leffler, Andrew Shirk

Williams Honors College, Honors Research Projects

The need for hands-on and face-to-face experiences in the engineering classroom is very great. The equations, principles, and concepts can all be learned, but without the visual and tactile application, these don’t always sink in or become concrete. A small-scale tensile test machine was designed, sourced, manufactured, and tested for the purpose of being applied in classroom settings to provide this experience to engineering students. Extensive research was performed concerning tensile machines on the market, the essential elements of which are the load cell, grips, crosshead, extensometer, motor, and frame. The raw materials for the frame were purchased and drawings …

Designing Composites For Graceful Failure, Amany G. Micheal Prof., Yehia Ahmed Bahei El Din Prof.

Architectural Engineering

When inevitable, failure in composite laminates is preferred to occur gracefully to avoid loss of property and possibly life. While the inherent inhomogeneity leads to slow dissipation of damage-related energy, overall failure is fiber-dominated and occurs in a rather brittle manner. Multidirectional plies usually give a more ductile response. Additionally, stiffness and strength as well as cost are important factors to consider in designing composite laminates. It is hence desirable to optimize for high mechanical properties and low cost while keeping graceful failure. Designing composite laminates with hybrid systems and layups, which permit gradual damage energy dissipation, are two ways …

Magnetic Refrigerator Device Based On La (Fexcoysi1-X-Y)13, Khushar Javed

Theses and Dissertations

Particles of Lanthanum-iron-silicide, La (Fe_xCo_ySi_1-x-y)₁₃exhibit different magnetic properties when stored in air compared to the same stored in water. The sample with a nominal composition of La(Fe0_.842Co_0.073Si_0.084)₁₃was prepared by arc-melting from elements under argon atmosphere. In recent years, there has been research conducted on different processes that could drastically reduce energy costs of cooling and replacing gas compressors with magnetocaloric materials. Magnetization measurements were carried out on this magnetocaloric material to characterize it in order to design magnetic refrigerator device based on it. The …

Investigation On The Mechanical Properties And Microstructure Analysis Of Micro-Resistance Spot Welding Between Stainless Steel 316l And Tl-6al-4v, Mohd Mansor Muhammad Safwan

Student Works (2020-2029)

In this study, ASS 316L and Ti-6Al-4V were welded together by micro-resistance spot welding (μRSW) at different combinations of welding parameters using specifically design electrode geometry in order to acquire the optimal combination of welding parameters. The welded joint were subjected to tensile shear strength test to determine the influence of welding current, welding time, welding force and different design of elctrode tip on the mechanical properties and the strength of the welded joint. The experiment was conducted by using full factorial design of experiment (DoE) with L27 orthogonal array and utilizing the analysis of variance (ANOVA) to obtain the …

Assessing Magnetic Iron Oxide Nanoparticles Properties Under Different Thermal Treatments, Erick S. Vasquez, Evan M. Prehn, Keisha B. Walters

Chemical and Materials Engineering Faculty Publications

Magnetic nanoparticle structures have been examined as potential carrier vehicles and substrates in a wide range of applications where they undergo mechanical, chemical and/or thermal manipulation to allow for their modification, conjugation and transport. For safe and effective use, it is imperative to not only measure the initial physicochemical and structural properties of nanomaterials, but also identify and quantify any property changes related to a loss of chemical and/or physical integrity during processing and usage conditions. In this study an assessment of iron oxide magnetic nanoparticle thermal stability using modulated differential scanning calorimetry (mDSC) and a controlled-heating system is conducted …

Effect Of Incorporating Pottery And Bottom Ash As Partial Replacement Of Cement, Bassam A. Tayeh, Doha M. Alsaffar, Lawend K. Askar, Asmahan Issa Jubeh

Karbala International Journal of Modern Science

This study addressed the environmental constraints in cement produc­tion. Ordinary Portland cement (OPC) was replaced with pottery powder (PP, produced by grinding locally available pottery) and bottom ash (BA) at 10%, 20% and 30% of cement mass. Moreover, 4% calcium chloride solution (CaCl₂.2H₂O) was used as mixing water. Material properties, such as standard consistency, setting time and compressive strength, were measured with different percentages of OPC replacement with PP and BA. Results indicated that the replacement with PP and BA increased the water demand to achieve the standard consistency. These results revealed that the strength evolution …

Study Of Amorphous Boron Carbide And Hydrogenated Boron Carbide Materials Using Molecular Dynamics And Hybrid Reverse Monte Carlo, Rajan Khadka

Graduate Theses/Dissertations

We present a computational study of amorphous boron carbide (a-B_xC) models using Molecular Dynamics (MD) studied with Stillinger-Weber (SW) and ReaxFF potential. The atomic structure factor (S(Q)), radial distribution function (RDF) and bond lengths comparison with other experimental and ab initio models shows that a random arrangement of icosahedra (B₁₂, B₁₁C) interconnected by chains (CCC, CBC) are present in a-B_xC. Afterward, Hybrid Reverse Monte Carlo (HRMC) technique is used to recreate a-B_xC structures. The existing SW potential parameters of Boron are optimized for the α-rhombohedral (Icosahedral B_{12 …}

Nanoscale Optical And Correlative Microscopies For Quantitative Characterization Of Dna Nanostructures, Christopher Michael Green

Boise State University Theses and Dissertations

Methods to engineer nanomaterials and devices with uniquely tailored properties are highly sought after in fields such as manufacturing, medicine, energy, and the environment. The macromolecule deoxyribonucleic acid (DNA) enables programmable self-assembly of nanostructures with near arbitrary shape and size and with unprecedented precision and accuracy. Additionally, DNA can be chemically modified to attach molecules and nanoparticles, providing a means to organize active materials into devices with unique or enhanced properties. One particularly powerful form of DNA-based self-assembly, DNA origami, provides robust structures with the potential for nanometer-scale resolution of addressable sites. DNA origami are assembled from one large DNA …

Effects Of Magnetic Domain And Twin Boundary Interactions On Magneto-Mechanical Properties Of Magnetic Shape Memory Alloys, Medha Veligatla

Boise State University Theses and Dissertations

Magnetic shape memory (MSM) alloys deform substantially when exposed to a magnetic field. This recoverable plastic deformation occurs through crystallographic twinning. Thereby the internal magnetic domain structure modulates the deformation mechanisms through the interaction of magnetic domains with twin boundaries. We study the meso scale magneto-structural interactions that affect the macroscopic material properties of MSM alloys. The study at the meso length scale is most effective as it allows for resolving interactions at magnetic domain wall width resolution with reasonable computing cost. We apply micromagnetics simulations to evaluate the evolution of magnetic domains, their interaction with twin boundaries, the distribution …

Why The Crackling Deformations Of Single Crystals, Metallic Glasses, Rock, Granular Materials, And The Earth’S Crust Are So Surprisingly Similar, Karin A. Dahmen, Jonathan T. Uhl, Wendelin J. Wright

Faculty Journal Articles

Recent experiments show that the deformation properties of a wide range of solid materials are surprisingly similar. When slowly pushed, they deform via intermittent slips, similar to earthquakes. The statistics of these slips agree across vastly different structures and scales. A simple analytical model explains why this is the case. The model also predicts which statistical quantities are independent of the microscopic details (i.e., they are "universal"), and which ones are not. The model provides physical intuition for the deformation mechanism and new ways to organize experimental data. It also shows how to transfer results from one scale to another. …

Combined Molecular Dynamics And Phase Field Simulation Of Crystal Melt Interfacial Properties And Microstructure Evolution During Rapid Solidification Of Ti-Ni Alloys, Sepideh Kavousi

LSU Doctoral Dissertations

Phase field method has become a popular tool to investigate the microstructure evolution during the solidification. Quantitative predictions using this method is still limited, and in this dissertation, we try to study this problem from different perspectives.

Most of the phase field models consider the solid-liquid interface to be in local equilibrium. Solidification during some manufacturing processes like selective laser melting, and electron beam additive manufacturing is rapid and far from equilibrium which can result in supersaturated solid solutions, segregation-free crystals, or metastable phases. Before obtaining any conclusions from the phase field simulations, we must know the answer for “which …