Materials Science and Engineering Commons^™

Effect Of Temperature Dropping During Solution Treatment During Rejuvenation Heat Treatment On Final Microstructures In Cast Nickel Base Superalloy, Grade Inconel-738, Aimamorn Promboopha, Sureerat Polsilapa, Panyawat Wangyao

Journal of Metals, Materials and Minerals

Generally, the rejuvenation heat treatment of degraded turbine blades, which were made of cast nickel based superalloy, Grade Inconel 738, usually consist of solution treatment condition with temperature range of 1125C- 1205C for 3 hours and then following with double aging processes, which include primary aging at 1055C for 1 hour and secondary aging at 845C for 24 hours. However, in practical working conditions of reheat treatment processed, the possible change of temperature during solution treatment can be obtained by error or malfunction of heating furnace, which usually provides the temperature dropping down. To simulate this effect, the dropping temperature …

Atom Probe Study Of Irradiation-Enhanced Α′ Precipitation In Neutron-Irradiated Fe–Cr Model Alloys, Yaqiao Wu

Materials Science and Engineering Faculty Publications and Presentations

Atom probe tomography (APT) was performed to study the effects of Cr concentrations, irradiation doses and irradiation temperatures on α′ phase formation in Fe–Cr model alloys (10–16 at.%) irradiated at 300 and 450 °C to 0.01, 0.1 and 1 dpa. For 1 dpa specimens, α′ precipitates with an average radius of 1.0–1.3 nm were observed. The precipitate density varied significantly from 1.1 × 10²³ to 2.7 × 10²⁴ 1/m³, depending on Cr concentrations and irradiation temperatures. The volume fraction of α′ phase in 1 dpa specimens qualitatively agreed with the phase diagram prediction. For 0.01 dpa …

Preparation And Characterization Of Epoxidized Natural Rubber And Epoxidized Natural Rubber/Carboxylated Styrene Butadiene Rubber Blends, Saowaroj Chuayjuljit, Thongchai Nutchapong, Onusa Saravari, Anyaporn Boonmahitthisud

Journal of Metals, Materials and Minerals

In this study, epoxidized natural rubber (ENR) with 30 mol % epoxidation (ENR-30) was first prepared from natural rubber (NR) latex via in situ performic epoxidation using 0.5 M hydrogen peroxide and 0.75 M formic acid at 50C for 4 h. The prepared ENR-30 was blended with three different loadings of carboxylated styrene butadiene rubber (XSBR) (10, 20 and 30 wt%) in the latex stage. All ENR-30/XSBR blends had longer scorch time and cure time than neat ENR-30 as examined on a moving die rheometer. The tensile properties (tensile strength, modulus at 300% strain and elongation at break), thermal stability …

Sandwich-Type Cobalt Tungstophosphate: Synthesis, Characterization And Catalytic Activity, Wimonrat Trakarnpruk, Aphiwat Wannatem, Jutatip Kongpeth

Journal of Metals, Materials and Minerals

odium tungstophosphate, Na9[HPW9O34].7H2O was synthesized by reaction in aqueous solution of sodium tungstate, phosphoric acid and acetic acid. It was used as a precursor for synthesis of sandwich-type cobalt tungstophosphate, K10[Co4(H2O)2(PW9O34)2].20H2O by reacting with cobalt chloride and potassium acetate. The potassium ion can be exchanged with tetrabutylammonium bromide. The characterization was carried out by means of elemental analysis, FT-IR, UV-vis diffuse reflectance spectroscopy (DR-UV-vis). The sandwich-type cobalt tungstophosphate was used to catalyze oxidation of cyclooctane with H2O2 as oxidant in absence and presence of phase transfer agent. The experimental results showed that with phase transfer agent, the sandwich-type cobalt tungstophosphate …

Peroxidase Inhibition Assay For The Detection Of Some Thiols By Carbon Screen Printed Electrodes Based On Square Wave Voltammetry, Wischada Jongmevasna, Orawon Chailapakul, Manchumas Hengsakul Prousoontorn

Journal of Metals, Materials and Minerals

Cassava peroxidase (CSP) from leaves of cultivar KU50 was used as an alternative peroxidase for the electrochemical detection of thiram and thiourea.Square-wave voltammetry (SWV) incorporated with screen-printed carbon electrode was applied for the investigation of peroxidase activity. It was based on the measurement of 3, 3-diaminobenzidine (DAB) electro active product catalyzed by CSP and horseradish peroxidase (HRP) in 0.04 M Britton-Robinson buffer, pH 6, containing urea hydrogen peroxide in 96-well microplate. The reaction mixture in the presence of either thiourea or thiram was performed in order to study their effects on DAB oxidation catalyzed by both peroxidases. From the result …

Properties Of Binary And Ternary Composites Of Polypropylene Containing Soybean Oil-G-Chitosan And Hydrophobic Phosphonated Silica, Natthaphop Suwannamek, Kawee Srikulkit

Journal of Metals, Materials and Minerals

PP/soybean oil-g-chitosan binary composite, PP/hydrophobic phosphonated silica binary composite, and PP/chitosan/hydrophobic phosphonated silica ternary composite were prepared. Firstly, the preparation of soybean oil-g-chitosan was carried out by surface hydrophobicity modification of chitosan powder with soybean oil maleate and hydrophobicallyphosphonated silica was prepared by silanization of phosphonated silica with hexadecyltrimethoxysilane (an organosilane). Binary and ternary composites were prepared using a twin screw extruder. It was found that soybean oil-g-chitosan not only caused a decrease in tensile strength but also enhanced flexibility of PP due to its plasticization effect. In the opposite direction, the addition of hydrophobic phosphonated silica resulted in an …

Effect Of Heating Rate On Morphology Of Anti-Reflective Tio2 Film Coated By Sol-Gel With Polyethylene Glycol, Kumpol Leelaruedee, Patama Visuttipitukul, Niti Yongvanich

Journal of Metals, Materials and Minerals

This research studies formation of thin porous TiO2 film prepared by Sol-gel process with spin coating. Polyethylene glycol with molecular weight of 6,000 g/mol (6kPEG) was used as a pore generating agent. The TiO2 film was calcination at 450C for 1 hour with different heating rate. It was found that heating rate strongly affects on morphology of TiO2 film due to grain coalescence. The lower heating rate tends to cause more coalescence resulting in coarsening of both grain and pore size. With higher heating rate, film density can be increased due to lower number of pores. On the other hand, …

An Updated Mineralogical Analysis Of Sediment Materials From Three Therapeutically-Used Peruvian Lagoons, Maria Luisa Ceron Loayza, Jorge Aurelio Bravo Cabrejos, F. A. R. Navarro, F. Urcia Ch.

Journal of Metals, Materials and Minerals

Herein, we determine the elemental, structural and mineralogical characterization of samples collected in three Peruvian lagoons; likewise, we investigate the physical and chemical properties of their fractions, both clay and magnetic. These lagoons are located in the Chilca District, Cate Province, southern Lima Region, Peru; their morphology has been altered since we carried out a previous study five years ago. The physical analytical techniques we used were energy dispersive X-ray fluorescence (EDXRF); X-ray diffractometry (XRD); and transmission Msbauer spectroscopy (TMS), at room and liquid-helium temperatures, and at low and high velocities. The results indicate that dolomite is the main clayey …

First-Principles Studies Of Perovskite Compounds For Thermoelectric Applications, Penelope E. Ackerman, Lan Li (Mentor)

Idaho Conference on Undergraduate Research

Computational modeling techniques have been used to provide detailed insights into the structure-property relationships of materials. We have collaborated with the National Institute of Standards and Technology to develop various perovskite compounds with desired thermoelectric properties. We have used density functional theory-based approaches to study structural stability and electrical properties of R₂(FeCo)O₆ perovskite compounds (R = Pr, Nd, Sm, Eu and Gd), for which Fe and Co randomly occupy the B-site. Vienna ab-initio simulation package (VASP) has been performed to optimize geometry and structure. Superlattice and locally disordered phases have been compared through a total energy minimization …

Investigation Of Electrical And Magneto Transport Properties Of Reduced Graphene Oxide Thin Films, Ariful Haque

Graduate Theses/Dissertations

Large area uniform thin films of reduced graphene oxide (RGO) was synthesized by pulsed laser deposition (PLD) technique. A number of structural properties including the defect density, average size of sp2 clusters, and degree of reduction were investigated by Raman spectroscopy and X-ray diffraction (XRD) analysis. The temperature dependent (5K - 350K) four terminal electrical transport property measurement confirms variable range hopping and thermally activated transport mechanism of the charge carriers at low (5K - 210K) and high temperature (210K - 350K) regions, respectively. The calculated localization length, density of states (DOS) near Fermi level (EF), hopping energy, and Arrhenius …

Design Of High Temperature Evaporator For Spectroscopic Study Of Equilibrated Vapor Phase Materials, Yarden Bosch

Graduate Theses/Dissertations

This work details the design, assembly, and testing of a high temperature electron beam evaporator for equilibrated vapor phase evaporation of rock oxides for the purpose of astrophysical characterization of extrasolar planetary atmospheres. Infrared spectroscopy of high temperature SiO2 atmosphere created through the electron beam evaporation technique and trapped by argon ice matrix isolation was performed to generate a reference spectrum against which absorption lines in stellar spectra taken during planetary transits can be compared. Studies demonstrate that water inclusions in milky quartz (SiO2) can be used to create H2O/SiO2 equilibrated atmospheres within a Knudsen cell. Modeling of exoplanet spectra …

Triboelectric Solar Generator Concept And Experimental Research, Elias Yazdanshenas

Mechanical & Aerospace Engineering Theses & Dissertations

In this thesis, a novel concept, a triboelectric solar generator (TSG ), is proposed for generation of high voltage direct current (HVDC) electricity from solar radiation. An experimental investigation was conducted to prove the concepts of charge generation through the triboelectric effect and charge transmission using semiconductors. The triboelectric effect, also known as the contact electrification, is a well-known physical phenomenon that electrostatic charges are generated by rubbing dissimilar materials. However, traditional triboelectric generators had never been commercialized due to their poor power output. Physically, it is due to the difficulty of charge transmission from insulators, which generate charges. The …

Inert-Gas Condensed Co–W Nanoclusters: Formation, Structure And Magnetic Properties, Farhad Reza Golkar-Fard

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Rare-earth permanent magnets are used extensively in numerous technical applications, e.g. wind turbines, audio speakers, and hybrid/electric vehicles. The demand and production of rare-earth permanent magnets in the world has in the past decades increased significantly. However, the decrease in export of rare-earth elements from China in recent time has led to a renewed interest in developing rare-earth free permanent magnets. Elements such as Fe and Co have potential, due to their high magnetization, to be used as hosts in rare-earth free permanent magnets but a major challenge is to increase their magnetocrystalline anisotropy constant, K₁, which largely …

Electromagnetic Induction By Ferrofluid In An Oscillating Heating Pipe, John Gabriel Monroe, Erick S. Vasquez, Zachary S. Aspin, Keisha B. Walters, Matthew J. Berg, Scott M. Thompson

Chemical and Materials Engineering Faculty Publications

No abstract provided.

Pt/C Modified Proton Exchange Membrane For Improved Fuel Cell Performance, Zhi Cui, Chao Wang, Shui-Yun Shen, Feng-Jing Jiang, Jun-Liang Zhang

Journal of Electrochemistry

The property of proton exchange membrane greatly affects the performance of proton exchange membrane fuel cells (PEMFC). During the operation of a PEMFC, the water produced at the cathode, the water vapor from the humidified feed gas and the water migrated by electro-dragging will reach a balance in the membrane and determine the resistance of PEMFC, and thus affect the performance of PEMFC. Normally, the PEMFC performance strongly depends on the relative humidity of the feed gas, and the performance decreases at lower humidity as a result of lower proton conductivity of the membrane. In this paper, we proposed to …

Preparation Of Zro2-Doped Nb/Pbo2 Electrode And Electrocatalytic Performance Of Methyl Orange Degradation, Li Zhang, Wen-Yan Dong, Tai-Lai Yang, Zhen-Hai Liang

Journal of Electrochemistry

The zirconium oxide (ZrO₂)-doped niobium based lead oxide (Nb/PbO₂) electrode was prepared by electrodeposition. The microstructures and electrochemical properties of Nb/ZrO₂+PbO₂ electrode were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), linear sweep voltammetry, electrochemical impedance spectroscopy and cyclic voltammotry. In addition, the Nb/PbO₂ electrode was used as an anode for the electrochemical degradation of methyl orange (MO). Results revealed that the ZrO₂ doping made the Nb/PbO2 electrode surface denser and rougher with smaller sized crystal particles, which increased the specific surface area and enhanced the electrocatalytic activity of the …

Electrochemical Mass Spectrometric Study Of Lithium-Oxygen Batteries, Xin-Xiu Yan, Li-Po Ma, Zhang-Quan Peng

Journal of Electrochemistry

Mass Spectrometry, coupled with electrochemistry, is a powerful research tool to study mechanisms for a broad range of electrode reactions by identifying and quantifying reaction products and intermediates. In this review, we summarize the recent advances in the Li-O₂ battery researches offered by electrochemical mass spectrometry based on our group investigations. These include the research progresses in electrolytes, cathode materials (electrocatalysts), and parasitic reactions, i.e., the key issues associated with Li-O₂ research. In addition, we also discuss the effects of irreversible side reactions involved in battery systems on charge and discharge processes.

Synthesis Of Graphene Wrapped Li-Rich Layered Metal Oxide And Its Electrochemical Performance, Meng-Yan Hou, Ke Wang, Xiao-Li Dong, Yong-Yao Xia

Journal of Electrochemistry

In present work, lithium-rich layered transition metal oxide (LLO) was synthesized by a co-precipitation method in combination with a solid-state reaction. The graphene wrapped Li-rich layered oxide composite (LLO/Gra) was obtained by sintering the LLO/GO composite at 300 ^oC for 30 min in an air. The morphologies and the electrochemical performances were characterized by means of SEM, TEM, XRD, XPS, EIS and charge/discharge tests. The results indicated that the LLOe particles were uniformly wrapped with graphene. The resulting material exhibited better rate capability than that of pristine LLO since the wrapped graphene demonstrated the enhanced electronic conductivity. Accordingly, the …

Research Progress In Carbon Coating On Lifepo4 Cathode Materials For Lithium Ion Batteries, Ning Zhang, Yong-Chang Liu, Cheng-Cheng Chen, Zhi-Qiang Zhu, Zhan-Liang Tao, Jun Chen

Journal of Electrochemistry

Olivine-structured LiFePO₄ has been received much attention because of its flat voltage profile, low cost, abundant material supply and better environmental compatibility. However, the poor electronic and ionic conductivities have limited its application in industry. One of the best methods to improve the electrochemical performance is carbon coating. In this review, we summarize the recent developments of LiFePO₄/C cathode. Moreover, the different effects caused by coating methods and carbon sources, as well as the mechanism of carbon coating on the properties of LiFePO₄/C are reviewed.

Current Status And Prospect Of Cathode Materials For Lithium Sulfur Batteries, Lan Zhou, Ai-Shui Yu

Journal of Electrochemistry

Elemental sulfur has been extensively investigated as a promising candidate of cathode material for next generation lithium secondary batteries. However, some troublesome issues, such as the low electric conductivity of sulfur (5×10^-30 S·cm^-1) and the high solubility of lithium polysulfide intermediates in organic electrolytes, resulting in a low utilization of active material and a redox shuttling of dissolved polysulfide ions between the sulfur cathode and the lithium anode, which eventually leads to a deposition of insoluble and insulating Li₂S₂/Li₂S on the electrode surface and a fast reduction in the specific capacity. …

Enhancing Stability Of Pem Fuel Cell Catalysts Via Support Changing, Xiao-Hong Xie, Zi-Dong Wei

Journal of Electrochemistry

The Pt/C catalyst with highly dispersed Pt nanoparticles supported on carbon has been widely used as the state-of the-art catalyst in proton exchange membrane fuel cells (PEMFCs), while the durability of Pt/C is one of the major barriers for large-scale applications of PEMFCs. Thus, enhancing the stability of Pt/C has been a hot issue in this field. In this review, we summarize the recent progress in enhancing the catalyst stability in the view of support material. The future prospects of the PEMFCs catalyst should focus on adopting more stable supports or strengthening the interactions between Pt and supports.

Lithium Air Batteries: Non-Aqueous And Hybrid Systems, Sheng-Fu Tong, Ping He, Xue-Ping Zhang, Shi-Yong Zhao, Hao-Shen Zhou

Journal of Electrochemistry

Developing energy storage devices and new materials, which match the requirements in electric vehicles (EVs) and hybrid electric vehicles (HEVs), is an effective way to balance the contradiction between the social development and the shortage of fossil energy and environment pollution. Rechargeable lithium-air (Li-air) batteries consisting of Li and oxygen as the anodic and cathodic reactants, respectively, have attracted much attention during the past decade due to their high theoretical specific energy. According to work conditions, the most studied types of Li-air batteries are non-aqueous, hybrid, and solid state electrolyte Li-air batteries. Challenges still exist in cathodes, anodes, electrolytes and …

Research Status And Application Prospects Of Limnpo4 As A New Generation Cathode Material For Lithium-Ion Batteries, Lai-Fen Qin, Yong-Gao Xia, Li-Peng Chen, Hua-Sheng Hu, Feng Xiao, Zhao-Ping Liu

Journal of Electrochemistry

Olivine-structured lithium manganese phosphate (LiMnPO₄) has the following advantages: excellent thermal stability, low cost, high safety and environmental benignity. Importantly, the theoretical energy density of LiMnPO₄ is about 20% higher than that of commercialized LiFePO₄ due to its higher Li⁺ intercalation potential of 4.1 V (vs. Li⁺/Li). Moreover, the high operating voltage of LiMnPO₄ is compatible with present non-aqueous organic electrolytes of lithium-ion batteries. Therefore, LiMnPO₄ is considered as a next generation cathode material for lithium-ion batteries. However, LiMnPO₄ suffers from poor electronic conductivity and low lithium diffusivity, resulting in …

Preparations And Applications Of Layered Carbon And Layered Carbon-Pbso4 Composite, Shu-Kai Zhang, Hao Zhang, Wei-Hua Xue, Jie Cheng, Wen-Feng Zhang, Gao-Ping Cao, Hai-Lei Zhao, Yu-Sheng Yang

Journal of Electrochemistry

The layered carbon materials (similar to graphene) have been synthesized by chemical vapor deposition (CVD) on the cheap catalyst (potassium or sodium carbonate substrate). The layered-carbon- lead sulfate (PbSO₄) composite could be prepared by in situ chemical deposition based on the layered carbon. The XRD, SEM and TEM results showed that the layered carbon materials was amorphous carbon layer, and the composite was a compound made of fine lead sulfate grains and layered carbon. Thermogravimetric analysis determined the carbon content in the composite. Adding a certain amount of layered carbon or layered-carbon-PbSO₄ composite into negative active materials …

Electrolytes For Lithium And Lithium-Ion Batteries, Zong-Rang Zhang

Journal of Electrochemistry

This is an up-to-date book published by Springer last year and focuses on the field of the electrolytes for lithium and lithium-ion batteries. A brief introduction and review of this book are given in this paper. The main contents of this book are introduced briefly in the order of ten different chapters along with a short review of recent progress in those fields.

Analysis Of Particle Transport And Deposition Of Micron-Sized Particles In A 90° Bend Using A Two-Fluid Eulerian–Eulerian Approach, Erick S. Vasquez, Keisha B. Walters, D. Keith Walters

Chemical and Materials Engineering Faculty Publications

Two-phase flows involving dispersed particle and droplet phases are common in a variety of natural and industrial processes, such as aerosols, blood flow, emulsions, and gas-catalyst systems. For sufficiently dilute particle/aerosol phases, a simplified one-way coupling is often assumed, in which the continuous primary phase is unaffected by the presence of the dispersed secondary phase and standard CFD methods can be applied. To predict the transport and deposition of the particle phase, typically a Lagrangian particle-tracking or Eulerian one-fluid/two-phase drift-flux approach is used. Here, a full two-fluid Eulerian modeling approach is presented for coarse particles (>1 μm), in which …

Low-Cost Open-Source Voltage And Current Monitor For Gas Metal Arc Weld 3d Printing, Anthony Pinar, Bas Wijnen, Gerald C. Anzalone, Timothy C. Havens, Paul G. Sanders, Joshua M. Pearce

Department of Materials Science and Engineering Publications

Arduino open-source microcontrollers are well known in sensor applications for scientific equipment and for controlling RepRap 3D printers. Recently low-cost open-source gas metal arc weld (GMAW) RepRap 3D printers have been developed. The entry-level welders used have minimal controls and therefore lack any real-time measurement of welder voltage or current. The preliminary work on process optimization of GMAW 3D printers requires a low-cost sensor and data logger system to measure welder current and voltage. This paper reports on the development of a low-cost open-source power measurement sensor system based on Arduino architecture. The sensor system was designed, built, and tested …

Diffusion Of A Janus Nanoparticle In An Explicit Solvent: A Molecular Dynamics Simulation Study, Ali Kharazmi, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

Molecular dynamics simulations are carried out to study the translational and rotational diffusion of a single Janus particle immersed in a dense Lennard-Jones fluid. We consider a spherical particle with two hemispheres of different wettabilities. The analysis of the particle dynamics is based on the time-dependent orientation tensor, particle displacement, as well as the translational and angular velocity autocorrelation functions. It was found that both translational and rotational diffusion coefficients increase with decreasing surface energy at the nonwetting hemisphere, provided that the wettability of the other hemisphere remains unchanged. We also observed that in contrast to homogeneous particles, the nonwetting …

Consumer Perceptions Towards Package Designs: A Cross Cultural Study, Romica Chandra Lal, Fritz Yambrach, Lucy Mcproud

Journal of Applied Packaging Research

The choice of one package or the other can be an economic decision or can be influenced by cultural acceptance or perception of individual convenience. Product package systems can be designed for one-time use or multiple-use purposes. Package perceptions in different countries typically develop from a variety of factors, including climate, lifestyle, and cultural acceptance with regard to particular products. In an increasingly global economy with multinational firms marketing products worldwide, it is important to understand the differences between consumer needs and consumer responses to product-package systems.

The objective of this research was to examine consumer perceptions of different product …

Burner, Emitter, And Recuperator Development For Lightweight Thermophotovoltaic Power Supply, Lewis Fraas, Leonid Minkin, J. Avery, Hui She, L. Ferguson, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Like batteries, thermophotovoltaic generators produce DC electricity quietly. TPV uses infrared photovoltaic cells to convert infrared radiation from a combustion heated ceramic IR emitter. However, because the specific energy in a hydrocarbon fuel like propane or butane is 12,900 Wh/kg, much larger than the specific energy of 145 Wh/kg for a Li-ion battery, TPV is very promising as a lightweight DC power supply. A portable cylindrical thermophotovoltaic (TPV) battery replacement concept has been previously described. It consists of a cylindrical TPV receiver assembly using simple diffused junction GaSb IR cells along with a novel omega recuperator and a novel doped …