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2018

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Articles 271 - 300 of 689

Full-Text Articles in Materials Science and Engineering

A Comparative Study Of Nanofibrillated Cellulose And Microcrystalline Cellulose As Reinforcements In All-Cellulose Composites, S Tanpichai Jul 2018

A Comparative Study Of Nanofibrillated Cellulose And Microcrystalline Cellulose As Reinforcements In All-Cellulose Composites, S Tanpichai

Journal of Metals, Materials and Minerals

The reinforcing abilities of nanofibrillated cellulose (NFC) and microcrystalline cellulose (MCC) in composites were investigated and compared. All-cellulose composites were prepared using the dissolved MCC as the matrix, and NFC and MCC were introduced as the reinforcing phase. With the addition of MCC, tensile strength of the composites decreased; on the other hand, the higher tensile strength of the composites with NFC was found with increasing a NFC content. Strong interfacial interaction between the matrix and reinforcing phase could be obtained at a low content of the reinforcement was observed. At a higher content of the reinforcement the fiber pull-out …

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Effect Of Tempering Temperature On Microstructure And Mechanical Properties Of Low Alloy Steel In Quenched Tempered Conditions, V Yadav, A K. Singh, G Sahoo Jul 2018

Effect Of Tempering Temperature On Microstructure And Mechanical Properties Of Low Alloy Steel In Quenched Tempered Conditions, V Yadav, A K. Singh, G Sahoo

Journal of Metals, Materials and Minerals

The effect of tempering temperature on the microstructure and mechanical properties of a low alloy steel has been investigated using optical microscopy, hardness testing and Charpy V-notch impact testing at -20°C, -40°C and -60°C. At first, the laboratory based study revealed that tempering the specimens at 650°C resulted in lowest hardness with highest impact energy. Based on this, the heat-treated industrial steel showed sufficiently high toughness after Charpy V-notch impact testing at -40°C. Fractography after impact testing showed predominately ductile dimple rupture in the sample tempered at 650°C. The presence of decomposed martesitic laths in prior austenite was noticed in …

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Thermal And Mechanical Properties Of An Epoxidized Natural Rubber Composite Containing A Li/Cr Co-Doped Nio-Based Filler, B Khumpaitool, S Utara, P Jantachum Jul 2018

Thermal And Mechanical Properties Of An Epoxidized Natural Rubber Composite Containing A Li/Cr Co-Doped Nio-Based Filler, B Khumpaitool, S Utara, P Jantachum

Journal of Metals, Materials and Minerals

Li and Cr co-doped NiO-based (LCNO) filler was successfully synthesized by the sol-gel process using metal nitrate compounds as starting materials and citric acid as a crosslinking agent, followed calcination at a temperature of 1000˚C for 3 h. Composites of Li and Cr co-doped NiO/epoxidized natural rubbers with 25 mol% epoxidation (abbreviated as LCNO/ENR-25) were prepared by mixing using a two-roll mill. The ENR-25 was blended with 0.5, 1, 2 and 3 phr (parts per hundred of rubber) of LCNO and the specimens were shaped at 160˚C using compression molding. The LCNO/ENR-25 composites were characterized by thermogravimetric analysis (TGA), Fourier-transform …

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Utilization Of Coal Fly Ash As A Raw Material For Refractory Production, R Sukkae, S Suebthawilkul, B Cherdhirunkorn Jul 2018

Utilization Of Coal Fly Ash As A Raw Material For Refractory Production, R Sukkae, S Suebthawilkul, B Cherdhirunkorn

Journal of Metals, Materials and Minerals

In this research, fireclay bricks were produced using fire clay and coal fly ash as raw materials. Coal fly ash was added to the mixture from 10-50 wt%. The disk shape samples were sintered at the temperatures of 1,100-1,400°C. The mechanical property, thermal property, phase structure and microstructure of the fireclay bricks were studied. It was found that coal fly ash can be used in the fabrication of fireclay bricks. The lower linear shrinkage and lower thermal conductivity were obtained as the higher amount of coal fly ash was added. However, bulk density and strength were lower in the samples …

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Material Properties Of Laser Powder Bed Fusion Processed 316l Stainless Steel, Steven Keckler Jul 2018

Material Properties Of Laser Powder Bed Fusion Processed 316l Stainless Steel, Steven Keckler

Graduate Theses & Non-Theses

Laser powder bed fusion additive manufactured 316L stainless steel specimens were evaluated to establish a baseline for future research in determining an optimized energy density and build orientation. Test specimens were printed at various energy densities. At each energy density, tensile and fatigue specimens were printed at 0o (longitudinal), 45o, and 90o (transverse) orientation to the build plate. Tensile and high cycle fatigue tests were performed then representative fracture surfaces were analyzed. The apparent melt track and dendrite size were evaluated using grain analysis software. Static loading of the tensile specimens showed a marginal difference in UTS for specimens with …

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Repeated Loading Model For Elastic-Plastic Contact Of Geomaterial, Jian Wang, Qimin Li, Changwei Yang, Caizhi Zhou Jul 2018

Repeated Loading Model For Elastic-Plastic Contact Of Geomaterial, Jian Wang, Qimin Li, Changwei Yang, Caizhi Zhou

Materials Science and Engineering Faculty Research & Creative Works

A new nonlinear hysteretic model with considering the loading, unloading, and reloading processes is developed based on Drucker—Prager yield criterion and finite-element analysis. This model can be used for multiple repeated elastic—plastic normal direction contact problems between two identical spherical geomaterials. After examining the influence of material properties, strain hardening, and loading histories, we found that the hysteretic phenomena (represented by residual displacement and plastic work) become weak after the first cycle, and the subsequent cycles step into elastic shakedown state eventually. A critical number of cycles can be used to estimate the state of ratchetting, plastic shakedown, as well …

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The Yielding Transition In Periodically Sheared Binary Glasses At Finite Temperature, Nikolai V. Priezjev Jul 2018

The Yielding Transition In Periodically Sheared Binary Glasses At Finite Temperature, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

Non-equilibrium molecular dynamics simulations are performed to investigate the dynamic behavior of three-dimensional binary glasses prepared via an instantaneous quench across the glass transition. We found that with increasing strain amplitude up to a critical value, the potential energy approaches lower minima in steady state, whereas the amplitude of shear stress oscillations becomes larger. Below the yielding transition, the storage modulus dominates the mechanical response, and the gradual decay of the potential energy over consecutive cycles is accompanied by reduction in size of transient clusters of atoms with large nonaffine displacements. In contrast, above the yield strain, the loss modulus …

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Enhanced Coupling Strength Gratings For Outcouplers In Optical Waveguides, Ruo-Hua He Jul 2018

Enhanced Coupling Strength Gratings For Outcouplers In Optical Waveguides, Ruo-Hua He

Electrical Engineering Theses and Dissertations

Gratings used for silicon photonic waveguides were demonstrated with outcoupling efficiency greater than 60% in a short grating length of 13 µm at a wavelength of 1550 nm. Due to problems of generating light from silicon, light has to be generated by either growing III-V material, wafer bonding III-V material to silicon, or externally generated light has to be coupled into and out of silicon photonic waveguides. Gratings have been used in semiconductor lasers to obtain single frequency operation. Some applications such as telecommunications require a narrow and single spectral line. And such single frequency lasers are typically distributed Bragg …

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Crystalline Silica In Compressed Rice Hull Coke Ash, T Okutani, E Ichikawa, H Nagai, T Hashimoto, T Makihata Jul 2018

Crystalline Silica In Compressed Rice Hull Coke Ash, T Okutani, E Ichikawa, H Nagai, T Hashimoto, T Makihata

Journal of Metals, Materials and Minerals

Compressed rice hull coke was produced by compressing rice hulls ground to less than 200 µm diameter at 1.22x106 N/m2 and 310˚C with an oxygen deficient atmosphere. The compressed rice hull coke had a 5 cm outer diameter, a 1.5 cm inner diameter and 35 cm length. The density of the coke is 1.2, and, the heat value is 16570 kJ·kg-1. In this study, 2 kg coke was combusted at the average temperature of 850˚C for 104 min with a maximum temperature of 860˚C. The ash was colored black-grey, and the form remained coke. The ash contained 95.4% silica with …

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Enhancement Of Mechanical, Thermal And Antibacterial Properties Of Sisal/Phbv Biocomposite By Fibre Modification, T Kittikorn, R Malakul, E Stromberg, M Ek, S Karlsson Jul 2018

Enhancement Of Mechanical, Thermal And Antibacterial Properties Of Sisal/Phbv Biocomposite By Fibre Modification, T Kittikorn, R Malakul, E Stromberg, M Ek, S Karlsson

Journal of Metals, Materials and Minerals

Lignocellulosic biocomposite is a promising biodegradable materials, though improvement of the interfacial adhesion between cellulose fibre and polymer matrix is still challenged. Therefore, this work investigated the effect of propionylation of sisal reinforced fibre in the sisal/polyhydroxybutyrate-co-valerate (PHBV) biocomposite. Propionylation involved esterification substitution of propionic anhydride to hydroxyl group of sisal fibre, where ester group (COOR) of propionylated fibre was successfully observed by Fourier transform Infrared spectroscopy (FTIR). Then mechanical and thermal properties were evaluated and biodegradation characteristics were assessed. The tensile strength and modulus of propionylated sisal/PHBV biocomposite were greater than unmodified sisal/PHBV, which revealed better compatibility at the …

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Carboxymethylchitosan-Based Hydrogels Crosslinked With Polydimethylsiloxane, N Rodkate, N Deepuppha, B Rutnakornpituk, M Rutnakornpituk Jul 2018

Carboxymethylchitosan-Based Hydrogels Crosslinked With Polydimethylsiloxane, N Rodkate, N Deepuppha, B Rutnakornpituk, M Rutnakornpituk

Journal of Metals, Materials and Minerals

Synthesis and properties of hydrophilic carboxymethylchitosan (CMC) hydrogels containing hydrophobic polydimethylsiloxane (PDMS) were herein presented. Fourier transform infrared spectroscopy indicated that PDMS can covalently bound to CMC chains with the use of hexamethylene-1,6-di-(aminocarboxysulfonate) (HDA), a water soluble crosslinker. Also, according to scanning electron microscopy, PDMS microphases with the size of 0.2-0.5 µm in diameter were thoroughly dispersed in CMC matrix. Addition of PDMS improved properties of the CMC hydrogels including increasing water vapor permeability and water swellability, improving tensile properties and increasing surface hydrophobicity. PDMS with different amounts (1-20 wt%) and molecular weights (2,000 and 8,000 g·mol-1) were added into …

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Simple And Rapid Preparation Of Cuo Film Using Silar Process For Application As Hole-Transporting Layer In P-I-N Perovskite Solar Cell, S Wongrerkdee, K Hongsith, S Choopun, K Lohawet, P Kumno Jul 2018

Simple And Rapid Preparation Of Cuo Film Using Silar Process For Application As Hole-Transporting Layer In P-I-N Perovskite Solar Cell, S Wongrerkdee, K Hongsith, S Choopun, K Lohawet, P Kumno

Journal of Metals, Materials and Minerals

Copper oxide (CuO) films are considered to be an alternative metal oxide semiconductor for hole-transporting layer application in p-i-n perovskite solar cells due to their unique properties including intrinsic p-type materials and energy band level matching. The films can be synthesized using several methods such as sputtering, solution process and spin-coating processes. However, using the successive ionic layer adsorption and reaction (SILAR) process to prepare a CuO hole-transporting layer in p-i-n perovskite solar cells is still underreported. Thus, this study prepared the SILAR processed CuO films and applied as a hole-transporting layer in p-i-n perovskite solar cells. The results showed …

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Influence Of Blt Content On Phase Structure And Electrical Properties Of (1-X)Bt-Xblt Ceramic, N Thongmee, R Sumang, S Pojprapai, T Klaytae Jul 2018

Influence Of Blt Content On Phase Structure And Electrical Properties Of (1-X)Bt-Xblt Ceramic, N Thongmee, R Sumang, S Pojprapai, T Klaytae

Journal of Metals, Materials and Minerals

(1-x)BaTiO3-x(Bi3.25La0.75)Ti3O12; (1-x)BT-xBLT ceramics with x = 0-0.20 wt.% were prepared by a solid-state reaction method. The BaTiO3 (BT) and (Bi3.25La0.75)Ti3O12 (BLT) powders were, respectively, calcined at 1100°C and 750°C for 4 h. The (1-x)BT-xBLT samples were sintered between 1250°C and 1350°C. The structure exhibited a transformation from tetragonal to orthorhombic with increasing in BLT contents. The average grain size increased with increasing BLT contents. The maximum density and relative density about 6.19 ± 0.07 g/cm3and 99.3% were obtained for the composition of 0.95BT-0.05BLT. The Curie temperature (Tc) continuously decreased with increase in BLT contents. The dielectric constant showed a broad …

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Eggshell Waste: An Effective Source Of Hydroxyapatite For Photocatalyst, S Ummartyotin, H Manuspiya Jul 2018

Eggshell Waste: An Effective Source Of Hydroxyapatite For Photocatalyst, S Ummartyotin, H Manuspiya

Journal of Metals, Materials and Minerals

Interest in eggshell waste and its modification has been increasing rapidly. The outstanding property of eggshell waste is its high calcium carbonate content. This can be transformed to calcium oxide, and can provide a source of hydroxyapatite. As interest in clean technology has grown, the use of eggshell waste has become a focus of research. The objective of this review article is to characterize eggshell waste, describe the preparation of hydroxyapatite from eggshell waste and its modification, and discuss the use of hydroxyapatite as a photocatalyst.

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Recent Developments In The Field Of Metal Foam-Polymer Hybrid Materials: A Brief Overview, A Chaturvedi Jul 2018

Recent Developments In The Field Of Metal Foam-Polymer Hybrid Materials: A Brief Overview, A Chaturvedi

Journal of Metals, Materials and Minerals

In this paper, a brief overview of the various techniques employed for the preparation of metal foam-polymer hybrid/composite materials including infiltration/penetration and adhesive joining is given. Scanning electron microscopy (SEM) micro structural characterization method and various dependent mechanical properties such as stress-strain diagram, energy absorption etc is described. In addition, some possible applications of such materials are discussed. The paper intends to inform as well as educate the reader about the various aspects of this emerging field in a lucid manner.

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Super Hydrophobicity Of Sputtered Ptfe Films On Nanotextured Aluminum Surface, S Lumjeak, T Lertvanithpo, P Limnonthakul, M Horprathum, P Songsirirtthigul Jul 2018

Super Hydrophobicity Of Sputtered Ptfe Films On Nanotextured Aluminum Surface, S Lumjeak, T Lertvanithpo, P Limnonthakul, M Horprathum, P Songsirirtthigul

Journal of Metals, Materials and Minerals

In this research, the superhydrophobic surface was prepared by using the polytetrafluoroethylene (PTFE) thin films which deposited on aluminum (Al) nanotextures. The Al nanotextures have been prepared under different alkaline-treatment concentrations, and deposited with the PTFE thin films by the RF magnetron sputtering technique. During the alkaline treatments, the Al surface was immersed in the potassium hydroxide (KOH) solution with the concentrations of 1 mM to 0.10 mM. Then, the samples of PTFE films were deposited on Al nanotextures were characterized; the crystal structures, chemical compositions, physical morphologies, and surface roughness by photoelectron spectroscopy (PES), field-emission scanning electron microscopy (FE-SEM) …

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Aluminium-Sic Composite: Study Of Its Mechanical Properties, D Sánchez-García, A Herrera-Vázquez, J Hinojosa-Torres Jul 2018

Aluminium-Sic Composite: Study Of Its Mechanical Properties, D Sánchez-García, A Herrera-Vázquez, J Hinojosa-Torres

Journal of Metals, Materials and Minerals

Cylindrical specimens with geometries and sizes, in agreement with the standard of American Society for Testing Materials (ASTM), they were used to characterize the tension behaviour of the composite. A significant effect of the SiC shape/size on the tensile behaviour of aluminium-based composite was observed, caused by the differences between the superheat (993 K) and the mould temperatures (333 K, 473 K, 623 K) in the melting practice. Ultimate tensile stress and Fracture Toughness factor for the composite showed a numerical advantage over the corresponding ones to the aluminium at a solidification speed of 82.5 K·s-1. At the mould temperature …

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Wear Properties Of Boron Added High Strength Low Alloy (Hsla) Sae 8620 Steel, M Musa, A G. Mohammed, A Muhammad Jul 2018

Wear Properties Of Boron Added High Strength Low Alloy (Hsla) Sae 8620 Steel, M Musa, A G. Mohammed, A Muhammad

Journal of Metals, Materials and Minerals

The High Strength Low Alloy (HSLA) SAE 8620 steel with different contents of boron in ppm rate used in bearings, automotive gearing and automotive body components applications were studied. We report the relationship between wear properties, microstructural characterization and hardness properties of the steel. The steel chemical composition is selected to obtain relatively high mechanical properties with different boron contents. Increasing the normalization temperature and boron content, shows ferrite grain-size becomes larger when compared to lower normalization temperatures and boron content. With differences in boron content, only 2 HBN were measured from the average hardness of 3.3 ppm and 13.5 …

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Atomic Diffusion In The Feal Alloy: A Research Via The Kinetic Monte Carlo Method, E V Manrique Castillo, F A. Reyes Navarro Jul 2018

Atomic Diffusion In The Feal Alloy: A Research Via The Kinetic Monte Carlo Method, E V Manrique Castillo, F A. Reyes Navarro

Journal of Metals, Materials and Minerals

For a binary alloy with an ordered structure B2, we research the atomic migration by means of kinetic Monte Carlo simulations, where the atomic migration results from the exchange of positions between an atom and a vacancy in a rigid lattice. The atomistic kinetic model we used is based on the jump rate theory and the residence time algorithm, wherein we consider the pair interactions between neighbours up to the next-nearest neighbours. Likewise, we determine the ratio of the diffusion coefficients as a function of temperature and investigate the antiphase boundary mobility in the last stages of the ordering process. …

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Investigation Of Erosive Wear Behaviour Of Tungsten Carbide Cobalt Coated Metal Matrix Composites Using Ann, M Pasha, M Kaleemulla Jul 2018

Investigation Of Erosive Wear Behaviour Of Tungsten Carbide Cobalt Coated Metal Matrix Composites Using Ann, M Pasha, M Kaleemulla

Journal of Metals, Materials and Minerals

An artificial neural network (ANN) model was employed on erosive wear result of aluminium 7034 T6 reinforced with different weight percentage of Al2O3 and SiC with tungsten carbide cobalt (WC-Co) coated composites. WC-Co in the form of powder was pretreated before coating, to identify the inflence of pretreatment on the substrate. The WC-Co coating was deposited with high velocity oxy fuel (HVOF) sparay method. The microstructural examination was carried through scanning electron microscope (SEM) and to identify the elemental composition of coated specimens, energy dispersive X-ray analysis (EDX) was used. These material charecterisation shows that pretreated WC-Co coated Al 7034 …

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Starch Consolidation Of Porous Fused Silica Ceramics, K Kanlai, T Wasanapiarnpong, B Wiratphinthu, K Serivalsatit Jul 2018

Starch Consolidation Of Porous Fused Silica Ceramics, K Kanlai, T Wasanapiarnpong, B Wiratphinthu, K Serivalsatit

Journal of Metals, Materials and Minerals

Starch consolidation is a forming technique, in which ceramic suspension is consolidated by gelatinization of starch under suitable temperature. This technique is promising for fabricating porous ceramics because starch can act as a binder as well as a pore former. In this study, porous fused silica ceramics were prepared by starch consolidation using glutinous rice flour as a gelling agent. The 29 vol% solid loading of fused silica slurries with the addition of glutinous rice flour were prepared. After mixing the slurries were poured into a plastic mold and kept in an oven at 75ºC for an hour. The green …

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Synthesis Of Nanoparticulate Ti-Doped Zno By Solution Combustion Technique, O Jongprateep, P Deedit, R Puranasamriddhi, K Meesombad Jul 2018

Synthesis Of Nanoparticulate Ti-Doped Zno By Solution Combustion Technique, O Jongprateep, P Deedit, R Puranasamriddhi, K Meesombad

Journal of Metals, Materials and Minerals

ZnO and TiO2 have been widely accepted as prominent photocatalysts. Enhancement of their photocatalytic activities can be achieved through particle refinement and doping. Solution combustion technique is a simple and cost-effective method capable of producing fine ceramic powders with homogeneous chemical compositions. It is, therefore, employed in this research project as the technique to synthesize nanometer-sized Ti-doped ZnO powders. The research also aimed at examining a relationship among doping contents, chemical composition, particle sizes, and photocatalytic performance of the synthesized powder. Compositional analysis revealed that the solubility limit of Ti in zinc oxide was within the range of 3 at% …

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Boro-Austempering Treatment Of Ductile Cast Irons, Fábio Edson Mariani, Carolina Soares, Amadeu Lombardi Neto, George Totten, Luiz Carlos Casteletti Jul 2018

Boro-Austempering Treatment Of Ductile Cast Irons, Fábio Edson Mariani, Carolina Soares, Amadeu Lombardi Neto, George Totten, Luiz Carlos Casteletti

Mechanical and Materials Engineering Faculty Publications and Presentations

Samples of ductile cast irons alloyed with Cu, Cu-Ni and Cu-Ni-Mo were austempered, borided and boro-austempered and characterized for hardness and micro-adhesive wear behavior. The kinetics of layer formation was also studied. The boriding method used was molten borax bath, in periods of 2 and 4 hours at temperatures of 850, 900 and 950º C. The direct austempering treatment was performed immediately following the boriding treatment (from 850, 900 and 950º C) using molten salt baths at temperatures of 240, 300 and 360º C for 4 hours (boro-austempering treatment). For comparative purposes, the conventional austempering treatment was also conducted. Optical …

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Optimization Of Top Contact For Cu(In,Ga)Se2 Solar Cells, Grace Cherukara Rajan Jul 2018

Optimization Of Top Contact For Cu(In,Ga)Se2 Solar Cells, Grace Cherukara Rajan

Electrical & Computer Engineering Theses & Dissertations

As world energy demands continue to increase, the need to generate electricity from a broader variety of sources, including renewables, is more critical than ever. With costs still 30% higher than those of natural gas, solar energy is a viable contender, but more progress is needed to level the playing field with other forms of energy generation. The overall energy security can be enhanced by diversifying the energy supply. Among them, Cu(In,Ga)Se2 (CIGS) has gained significant momentum as a possible high efficiency and low cost thin film solar cell material. The capacity to scale up any photovoltaic technology is …

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Non-Destructive Evaluation For Composite Material, Desalegn Temesgen Delelegn Jul 2018

Non-Destructive Evaluation For Composite Material, Desalegn Temesgen Delelegn

Electrical & Computer Engineering Theses & Dissertations

The Nondestructive Evaluation Sciences Branch (NESB) at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) has conducted impact damage experiments over the past few years with the goal of understanding structural defects in composite materials. The Data Science Team within the NASA LaRC Office of the Chief Information Officer (OCIO) has been working with the Non-Destructive Evaluation (NDE) subject matter experts (SMEs), Dr. Cheryl Rose, from the Structural Mechanics & Concepts Branch and Dr. William Winfree, from the Research Directorate, to develop computer vision solutions using digital image processing and machine learning techniques that can help identify …

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Sponsored Libre Research Agreements To Create Free And Open Source Software And Hardware, Joshua M. Pearce Jul 2018

Sponsored Libre Research Agreements To Create Free And Open Source Software And Hardware, Joshua M. Pearce

Michigan Tech Publications, Part 1

As a growing number of companies reject intellectual property (IP) monopoly-based business models to embrace libre product development of free and open source hardware and software, there is an urgent need to refurbish the instruments of university-corporate research partnerships. These partnerships generally use a proprietary standard research agreement (PSRA), which for historical reasons contains significant IP monopoly language and restrictions for both the company and the university. Such standard research agreements thus create an artificial barrier to innovation as both companies using a libre model and universities they wish to collaborate with must invest significantly to restructure the contracts. To …

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Effects Of Automated Fiber Placement On High Strain Rate Compressive Response Of Advanced Composites, Alexander Trochez Jul 2018

Effects Of Automated Fiber Placement On High Strain Rate Compressive Response Of Advanced Composites, Alexander Trochez

Mechanical & Aerospace Engineering Theses & Dissertations

Automated Fiber Placement (AFP) technology shows great promise in manufacturing carbon fiber composite structures. However, intermittent defects occur in the process that can affect the overall mechanical performance of the structure. The aim of this work is to investigate the effects of deliberately placed principal defects (Gap, Overlap, and Fold) on the compressive response under quasistatic (strain rate ~10-3 s-1) and dynamic (strain rate ~103 s-1) loading conditions. The controlled defects were placed at the laminate level in different orientations and depths. High strain rate compression experiments were conducted using a split Hopkinson pressure bar (SHPB) …

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Interface Structure And Deformation Mechanisms Of Mg/Nb Multilayers, Xinyan Xie Jul 2018

Interface Structure And Deformation Mechanisms Of Mg/Nb Multilayers, Xinyan Xie

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

Magnesium (Mg) and its alloys, as the lightest structural materials, are very attractive for a range of weight sensitive applications, such as aircraft engine, transportation industry and so on. However, their further applications are limited due to the weak properties, such as the low strength and poor ductility. In recent years, advanced techniques aiming at the modification of the microstructures, have been developed to promote the properties of Mg and its alloys, such as modifying the texture, refining the grain size, forming the intermetallic phase, and introducing the interfaces or stacking faults into the systems. Constructing Mg/Nb multilayers, which introduces …

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Energy Conversion System For Travelers (Ecost), Thipok Bovornratanaraks Jun 2018

Energy Conversion System For Travelers (Ecost), Thipok Bovornratanaraks

The International Student Science Fair 2018

We have innovated “The Energy Conversion System for Travelers” or the ECoST. With the fact that most travelers have wheeled cabin-bags, whilst walking, the wheels will rotate so why don’t we harvest electricity from this kinetic energy? We thus install our innovation, the ECoST, to the bag to generate electricity from the spinning wheels. The electricity is then kept in the storage unit and ready to charge your empty battery devices in an emergency case via a USB port. To make life easy, our ECoST was designed to replicate the power bank charging method; therefore, we can charge …

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Feco2o4 As An Anode Material For Lithium Ion Batteries, Chelsea Wong Jun 2018

Feco2o4 As An Anode Material For Lithium Ion Batteries, Chelsea Wong

The International Student Science Fair 2018

Lithium ion batteries (LIBs) are commonly found in many portable electronic appliances due to their ability to be rechargeable. Currently, commercial anodes in Li-ion batteries (graphite) have a theoretical capacity of around 372 mAh/g, while FeCo2O4 that will be investigated as the anode material has a theoretical capacity of 901.985mAh/g, more than double of the current commercial anode’s capacity. Earlier work done by Sharma et al also showed that FeCo2O4 has a very promising initial capacity of 827mAh/g. As such, the engineering goal is to produce a battery that will have a higher capacity than the current commercial Li-ion batteries …

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