Materials Science and Engineering Commons^™

Corrosion And Leaching Study Of Low Copper (I) Oxide Paints For Antifouling Application, Hansika Parekh

Material Science and Engineering Theses - Archive

Global environmental concern/economy challenges necessitate innovation of AFP's with novel additives offering improved corrosion protection, and biofouling resistance. Dispersing large proportions (40-70%) of Cu/Cu2O in paints although inexpensive produces excessive leaching & heavy accumulation of copper in marine. This study aims at formulating AFP's with reduced Cu2O levels along with novel additives, targeting controlled copper release around 15 ug/cm2/day. In the present study several formulations were prepared using Viscoplex (PAMA in mineral oil), Ionomer ED-SPAN and CuDDP. Substitute ocean water was prepared to simulate marine environmental conditions and perform leaching studies of different formulations. A variety of preliminary elimination tests …

Solar Selective Optical Coating Made With Metal Nanopaticles For Photovoltaic Thermal Applications, Xin Wang

Material Science and Engineering Theses - Archive

The goal of this research is to fabricate solar selective reflector with suitable optical properties and high thermal and chemical stability for using in the photovoltaic thermal window. While the reflector allows some transmittance in visible spectrum, the mid/far infrared light needs to be reflected back into the window minimizing the IR radiation loss. Nickel/alumina composite was proposed as the solar selective reflector. This thesis consists of two parts - one part concerning the fabrication and characterization of solar selective reflector and another dealing with an optical modeling to simulate the optical properties of the solar selective reflector. The alumina …

A Computational Study On Novel Carbon-Based Lithium Materials For Hydrogen Storage And The Role Of Carbon In Destabilizing Complex Metal Hydrides, Mohammed Minhaj Ghouri

Doctoral Dissertations

One of the major impediments in the way of the realization of hydrogen economy is the storage of hydrogen gas. This involves both the storage for stationary applications as well as that of storage onboard vehicles for transportation applications. For obvious reasons, the system targets for the automotive applications are more stringent. There are many approaches which are still being researched for the storage of hydrogen for vehicular applications. Among them are the high pressure storage of hydrogen gas and the storing of liquid hydrogen in super insulated cryogenic cylinders. While both of them have been demonstrated practically, the high …

Impacting Testing Of High Temperature Ceramics Through The Use Of A Vitiated Heater For Hot And Cold Fire Collisions, Adrian Trejo

Open Access Theses & Dissertations

Material testing is a crucial step during the design process as particular materials serve as safety and life saving conditions. In this study, a MoSi2 is chosen as the target specimen to undergo impact under high temperatures. An impact apparatus is designed and constructed for the purpose of propelling alumina particles at high velocities. A nozzle using compressed nitrogen gas is used to fire the particle at the desired velocities. Due to the possibility of thermal shock occurring at higher temperatures, a separate nozzle utilizing vitiation heating is designed to fire the particle at equally higher temperatures to prove the …

Phase-Field Simulation Of Microstructural Development Induced By Interdiffusion Fluxes Under Multiple Gradients, Rashmi Mohanty

Electronic Theses and Dissertations

The diffuse-interface phase-field model is a powerful method to simulate and predict mesoscale microstructure evolution in materials using fundamental properties of thermodynamics and kinetics. The objective of this dissertation is to develop phase-field model for simulation and prediction of interdiffusion behavior and evolution of microstructure in multiphase binary and ternary systems under composition and/or temperature gradients. Simulations were carried out with emphasis on multicomponent diffusional interactions in single-phase system, and microstructure evolution in multiphase systems using thermodynamics and kinetics of real systems such as Ni-Al and Ni-Cr-Al. In addition, selected experimental studies were carried out to examine interdiffusion and microstructure …

Damage Characterization Of Beam-Column Joints Reinforced With Gfrp Under Reversed Cyclic Loading, Aly M. Said

Civil and Environmental Engineering and Construction Faculty Research

The use of fiber reinforced polymer (FRP) reinforcement in concrete structures has been on the rise due to its advantages over conventional steel reinforcement such as corrosion. Reinforcing steel corrosion has been the primary cause of deterioration of reinforced concrete (RC) structures, resulting in tremendous annual repair costs. One application of FRP reinforcement to be further explored is its use in RC frames. Nonetheless, due to FRP's inherently elastic behavior, FRP-reinforced (FRP-RC) members exhibit low ductility and energy dissipation as well as different damage mechanisms. Furthermore, current design standards for FRP-RC structures do not address seismic design in which the …

Three-Dimensional Hydrogel Cell Culture Systems For Modeling Neural Tissue, John P. Frampton

Legacy Theses & Dissertations (2009 - 2024)

Two-dimensional (2-D) neural cell culture systems have served as physiological models for understanding the cellular and molecular events that underlie responses to physical and chemical stimuli, control sensory and motor function, and lead to the development of neurological diseases. However, the development of three-dimensional (3-D) cell culture systems will be essential for the advancement of experimental research in a variety of fields including tissue engineering, chemical transport and delivery, cell growth, and cell-cell communication. In 3-D cell culture, cells are provided with an environment similar to tissue, in which they are surrounded on all sides by other cells, structural molecules …

Complex Electronic States In Double-Layered Ruthenates (Sr1−Xcax)3ru2o7, Zhe Qu, Jin Peng, David Fobes, Leonard Spinu, Zhiqiang Mao

Physics Faculty Publications

The magnetic ground state of (Sr_1−xCa_x)₃Ru₂O₇ (0≤x≤1) is complex, ranging from an itinerant metamagnetic state (0≤x<0.08) to an unusual heavy-mass nearly ferromagnetic (FM) state (0.08<x<0.4), and finally to an antiferromagnetic (AFM) state (0.4≤x≤1). In this report we elucidate the electronic properties for these magnetic states, and show that the electronic and magnetic properties are strongly coupled in this system. The electronic ground state evolves from an AFM quasi-two-dimensional metal for x=1.0 to an Anderson localized state for 0.4≤x<1.0 (the AFM region). When the magnetic state undergoes a transition from the AFM to the nearly FM state, the electronic ground state switches to a weakly localized state induced by magnetic scattering for 0.25≤x<0.4, and then to a magnetic metallic state with the in-plane resistivity ρ_ab∝T^α (α>2) for 0.08<x<0.25. The system eventually transforms into a Fermi-liquid ground state when the magnetic ground state enters the itinerant metamagnetic state for x<0.08. When x approaches the critical composition (x∼0.08), …

Crystallography Open Database – An Open-Access Collection Of Crystal Structures, Saulius Grazulis, Daniel Chateigner, Robert T. Downs, A. F. T. Yokochi, Miguel Quirós, Luca Lutterotti, Elena Manakova, Justas Butkus, Peter Moeck, Armel Le Bail

Physics Faculty Publications and Presentations

The Crystallography Open Database (COD), which is a project that aims to gather all available inorganic, metal–organic and small organic molecule structural data in one database, is described. The database adopts an openaccess model. The COD currently contains 80,000 entries in crystallographic information file format, with nearly full coverage of the International Union of Crystallography publications, and is growing in size and quality.

Vibrational And Mechanical Properties Of 10 Mol % Sc2o3-1 Mol % Ceo2- Zro2 Electrolyte Ceramics For Solid Oxide Fuel Cells, Svetlana Lukich

Electronic Theses and Dissertations

Solid Oxide Fuel Cells (SOFCs) are emerging as a potential breakthrough energy conversion technology for clean and efficient production of electricity and heat from hydrogen and hydrocarbon fuels. Sc0.1Ce0.01ZrO2 electrolytes for Solid Oxide Fuel Cells are very promising materials because their high ionic conductivity in the intermediate temperature range 700°C-800°C. The vibration response of cubic and rhombohedral (β) 10 mol%Sc2O3 - 1 mol%CeO2 - ZrO2(Sc0.1Ce0.01ZrO2 ) both at room and high-temperatures is reported. The in-situ heating experiments and ex-situ indentation experiments were performed to characterize the vibrational behavior of these important materials. A temperature and stress-assisted phase transition from cubic …

An Analysis Of Silver Candlesticks From A Casting Point Of View: Originals, Copies, Forgeries, Jaromir Audy, Emil Evin

Research outputs pre 2011

Collecting silver artefacts has traditionally been a very popular hobby. Silver is addictive, therefore the number of potential collectors and investors appears to grow each year. Unfortunately, increases in the interest and buying potentials resulted in a number of forgeries manufactured and introduced to the open antique market. The items such as early silver candlesticks dictate a very high price, for many high quality fakes show very good appearances and matching similarities with originals. Such copies are traditionally manufactured by casting using the original items as patterns. Small details and variances in design features, position and shape of hallmarks, including …

Multicomponent Interdiffusion In Austenitic Ni-, Fe-Ni-Base Alloys And L12-Ni3al Intermetallic For High-Temperature Applications, Narayana Garimella

Electronic Theses and Dissertations

Interdiffusion in multicomponent-multiphase alloys is commonly encountered in many materials systems. The developments of multicomponent-multiphase alloys require control of microstructure through appropriate heat treatment, involving solid-state transformations, precipitation processes, and surface modification, where the interdiffusion processes play a major role. In addition, interdiffusion processes often control degradation and failure of these materials systems. Enhanced performance and reliable durability always requires a detailed understanding of interdiffusion. In this study, ternary and quaternary interdiffusion in Ni-Cr-X (X = Al, Si, Ge, Pd) at 900°C and 700°C, Fe-Ni-Cr-X (X = Si, Ge) at 900°C, and Ni3Al alloyed with Ir, Ta and Re at …

Formation Of Lyotropic Liquid Crystals Through The Self-Assembly Of Bile Acid Building Blocks, Karan Tamhane

Electronic Theses and Dissertations

Liquid crystalline materials (LCMs) have gained much popularity over the past century. The thermotropic forms of these materials have been extensively studied and employed in a range of innovative applications. The lyotropic liquid crystal systems that have been studied in the past have often been formed by the organization of natural and synthetic small molecules in solutions. In this study, we use self-assembled supramolecular structures as building blocks to fabricate lyotropic liquid crystals. We investigate the self-assembly of a naturally occurring bile acid called lithocholic acid (LCA), to form supramolecular fibrous and tubular structures in basic aqueous solutions. We control …

Electronic Properties And Microstructures Of Amorphous Sicn Ceramics Derived From Polymer Precursors, Tao Jiang

Electronic Theses and Dissertations

Polymer-derived ceramics (PDCs) are a new class of high-temperature materials synthesized by thermal decomposition of polymeric precursors. These materials possess many unique features as compared with conventional ceramics synthesized by powder metallurgy based processing. For example, PDCs are neither amorphous nor crystalline. Instead, they possess nano-domain structures. Due to the direct chemical-to-ceramic processing, PDCs can be used for making components and devices with complex shapes. Thus, understanding the properties and structures of these materials are of both fundamental and practical interest. In this work, the structures and electronic behavior of polymer-derived amorphous silicon carbonitrides (SiCNs) were investigated. The materials were …

Characterization And Aqueous Colloidal Processing Of Tungsten Nano-Powders, Zhengtao Yang

Electronic Theses and Dissertations

Extensive attention has been paid to consolidate nanoparticles into nanocrystalline components that possess better properties than their coarse-grained counterparts. Nanocrystalline monolithic tungsten (W) has been envisaged to possess better properties than coarse-grained tungsten and to improve the performance of many military components. Commercially available nano-W powders were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and Brunauer, Emmett, and Teller (BET) measurement. While the bulk of nano-W powders consisted of bcc-W as confirmed by XRD and TEM, much of their surface consisted of WO3 with traces of …

Sintering Additives For Nanocrystalline Titania And Processing Of Porous Bone Tissue Engineering Scaffolds, Arun Menon

Electronic Theses and Dissertations

Titania (Titanium dioxide, TiO2) has been researched as a promising biomaterial due to its excellent biocompatibility. However, the main limitation of titania is its poor mechanical properties which limit its use in many load-bearing applications. In this thesis report, the properties of titania were improved by doping with small quantities of MgO, ZnO and SiO2 as sintering additives. Nanocrystalline powder was selected, as it possesses outstanding properties over conventional coarse-grained powders due to reduced grain size. Nanocrystalline anatase powder of size 5-15 nm was synthesized via a simple sol-gel technique. Small quantities of dopants were introduced into pure titania powder, …

Classical Size Effect In Copper Thin Films: Impact Of Surface And Grain Boundary Scattering On Resistivity, Tik Sun

Electronic Theses and Dissertations

Surface and grain boundary electron scattering contribute significantly to resistivity as the dimensions of polycrystalline metallic conductors are reduced to, and below, the electron mean free path. A quantitative measurement of the relative contributions of surface and grain boundary scattering to resistivity is very challenging, requiring not only the preparation of suitably small conductors having independent variation of the two relevant length scales, namely, the sample critical dimension and the grain size, but also independent experimental quantification of these two length scales. In most work to date the sample grain size has been either assumed equal to conductor dimension or …

Study Of Corrosion Of Materials In The Sulfur-Iodine Hydrogen Production Cycle, Thao Trung Ho

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hydrogen is of great interest since the availability of traditional fossil fuels is in decline. Strictly speaking, hydrogen is not a primary source of energy but is an energy carrier, since energy typically must be used from another source (electricity, natural gas, coal, etc.) to produce it. Of hydrogen production techniques, the Sulfur-Iodine thermochemical water splitting process (S-I cycle), which was proposed by General Atomics (GA), is promising with its simplicity and high efficiency. Most of the chemicals are recycled except water. However, the S-I cycle operates in a harsh, corrosive environment in the presence of a mixture of iodine …

Morphology And Cathode Optimization For Efficient Polymer Bulk Heterojunction Solar Cells, Yi Yang

Material Science and Engineering Theses - Archive

Efficiency of polymer bulk heterojunction solar cell is highly dependent on the active layer morphology and can be controlled by specific experimental conditions. In this work, the influences of P3HT:PCBM blend composition, solution concentration, and the thermal annealing on the cell performance are presented. The maximum of Jsc and FF are reached when the weight percentage of PCBM in the blend is 60 % under which both high density of donor and accepter interfaces expecting the formation of efficient percolated electron transport paths. 36 mg/ml is found to be the optimum solution concentration for P3HT:PCBM blend and it can be …

Effect Of Aging On The Transformation Of Phases In Solder Joint Of Pbga Packaging, Jeong-Min Kim

Material Science and Engineering Theses - Archive

This study investigates the microstructural characteristics of 3.0Ag-0.5Cu-Sn (SAC305) solder joint as in assembled state, and their evolution with aging treatment at 100 and 150°C for various hours. Specific aim of the study is 1) to understand thermodynamic stability of as-reflowed microstructure (β-Sn dendrite, inner dendrite Cu6Sn5 intermetallic (IMC) compound, and the eutectic structure), 2) to find direction of their change with aging, and 3) to relate interfacial reaction to such evolution in microstructures. This investigation is spurred by the findings made in a separate study where fatigue resistance of solder joint and failure location shows markedly keen dependence on …

Structural, Magnetic And Surface Properties Of Rf Magnetron Sputtered Undoped Lanthanum Mangnite Thin Films, Varad Rajan Sakhalkar

Material Science and Engineering Theses - Archive

In the present study, polycrystalline and epitaxial undoped Lanthanum Manganite (LMO) thin films were deposited by using RF magnetron sputtering on three substrates, Si (100), MgO (100) and LaAlO₃ (100) to study the influence of the misfit strain at the substrate/film interface. The effect of processing conditions on the synthesis of LMO films was studied by conducting deposition on Si wafer. Films were characterized by X-Ray Diffraction (XRD), Atomic Force Microscope (AFM), Energy Dispersive Spectroscopy (EDS) and Superconducting Quantum Interference Device (SQUID) to investigate the influence of processing parameters on their structure and properties. Based on the initial study on …

Yttrium And Hydrogen Superstructure And Correlation Of Lattice Expansion And Proton Conductivity In The Bazr0.9y0.1o2.95 Proton Conductor, A. Braun, A. Ovalle, V. Pomjakushin, A. Cervellino, S. Erat, Wayne C. Stolte, T. Graule

Chemistry and Biochemistry Faculty Research

Bragg reflections in Y-resonant x-ray diffractograms of BaZr_0.9Y_0.1O_2.95 (BZY10) reveal that Y is organized in a superstructure. Comparison with neutron diffraction superstructure reflections in protonated/deuterated BZY10 suggests that both superstructures are linked, and that protons move in the landscape imposed by the Y. The thermal lattice expansion decreases abruptly for protonated BZY10 at T≥648±20 K, coinciding with the onset of lateral proton diffusion and suggesting a correlation of structural changes and proton conductivity. The chemical shift in the Y L₁-shell x-ray absorption spectra reveals a reduction from Y³⁺ toward Y²⁺ upon …

Preliminary Investigation Of Metallurgical Structure And Mechanical Properties Of Cast Iron With High Aluminum Content, Pavel Bizyukov

Dissertations and Theses @ UNI

The problem addressed in this study analyzed various properties of cast iron with high aluminum content. This grade of cast iron was projected for use in the automotive industry. The benefits provided with high aluminum content are lower specific gravity and relatively inexpensive source materials with the potential of achieving high temperature properties.

The purpose of the study was to select suitable source materials and determine an effective melting technique, to investigate metallurgical structure and mechanical properties at given chemical composition, and, finally, to provide elaborate results.

The design of the experiment included the following steps: (a) selection and preparation …

Start The Presses, Stephen V. Ducharme, Alexei Gruverman

Stephen Ducharme Publications

A simple nanoimprinting method creates arrays of ferroelectric polymer structures suitable for low-cost, non-volatile memories. With the development of nanoimprinted high-quality ferroelectric nanomesa arrays, it seems that we now have all the necessary ingredients to print inexpensive, disposable organic memory chips.

Polymer Composite And Nanocomposite Dielectric Materials For Pulse Power Energy Storage, P. Barber, S. Balasubramanian, Y. Anguchamy, S. Gong, A. Wibowo, H. Gao, Harry J. Ploehn, Hans-Conrad Zur Loye

Faculty Publications

This review summarizes the current state of polymer composites used as dielectric materials for energy storage. The particular focus is on materials: polymers serving as the matrix, inorganic fillers used to increase the effective dielectric constant, and various recent investigations of functionalization of metal oxide fillers to improve compatibility with polymers. We review the recent literature focused on the dielectric characterization of composites, specifically the measurement of dielectric permittivity and breakdown field strength. Special attention is given to the analysis of the energy density of polymer composite materials and how the functionalization of the inorganic filler affects the energy density …

Metal Induced Crystallization Of Silicon Thin Films, Sandeep Kumar Raju Sangaraju

UNLV Theses, Dissertations, Professional Papers, and Capstones

Low temperature crystallization of thin film silicon is important for many industrial applications including flat panel displays and silicon thin film solar cells. Unfortunately this remains a major challenge since crystallization temperature of silicon is above 1,000 degrees Celsius, thus limiting to substrates that can tolerate high temperatures. The inability to deposit crystalline thin films on glass substrates is the reason why flat panel display industry uses amorphous silicon for LCD active matrix displays. Thus the ability to deposit crystallized thin film silicon at low temperatures will have significant impact on thin film silicon applications. It has been observed that …

Mse News 2009, Department Of Materials Science And Engineering, Michigan Technological University

Department of Materials Science and Engineering Annual Reports

Table of Contents

• MSE Department Welcomes Engineering Fundamentals Chair
• MSE Department Welcomes New Professor
• Steel
• MSE Program Shines in US News Rankings
• MSE Alumnus Excelled in Mining Industry
• Student News
• Staff News
• Faculty News
• Alumni News

Model For Alumina Nanopore-Based Optical Filter, Nathan Lehman, Rama Venkat, Robert A. Schill

Electrical & Computer Engineering Faculty Research

Alumina nanopore structures find applications in magnetic sensors, optical filters, and various biological devices. In this work, we present a ray-optics model for the optical filter. We present a detailed simulation and a simplified analytical expression for the reflectance as a function of the alumina parameters such as pore diameter, pore density, alumina thickness, and a function of the wavelength and angle of incidence of the illuminating plane electromagnetic wave. The reflectance vs wavelength in the range of 400–800nm obtained from the simulation and the analytical expression are compared with that of the experiments for thin and thick alumina. All …

The Effect Of Near-Surface Metallurgy On The Machinability Of Cast Iron, William Dewey Peach

Masters Theses

"The increasing performance and durability of cutting tool inserts have created metallurgical challenges for production foundries to produce near-net shaped castings within strict dimensional tolerances. In order for foundries to take full advantage of the increased cutting speed capabilities, it becomes necessary to reduce machining allowances and produce much more stable casting surfaces. To accomplish this, a better understanding of the complex microstructures formed within the first 0.120 in. (3 mm) of the mold/metal interface (as-cast surface) is necessary. The goal of the work presented here was to examine the microstructures formed in the near-surface region of gray iron castings, …

Friction Stir Processing Of Laser Metal Deposited Ti-6al-4v, Romy Francis

Masters Theses

"Laser metal deposition (LMD) can form near net shaped components for aerospace applications. Ti-6Al-4V is a widely used aerospace alloy and fabrication of this alloy using LMD is gaining popularity. Improved mechanical properties are always a requirement in aerospace alloys and research is constantly being conducted to improve the properties of components formed from this alloy. Friction Stir Processing (FSP) in the past has been used as a method to change the surface properties of materials through microstructural modifications. The changes in properties can include hardness, corrosion resistance, fatigue strength, etc. The first section of this thesis is based on …