Thermal And Mechanical Properties Of An Epoxidized Natural Rubber Composite Containing A Li/Cr Co-Doped Nio-Based Filler,
2018
Chulalongkorn University
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 …
Utilization Of Coal Fly Ash As A Raw Material For Refractory Production,
2018
Chulalongkorn University
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 …
Optimization Of Top Contact For Cu(In,Ga)Se2 Solar Cells,
2018
Old Dominion University
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 …
Non-Destructive Evaluation For Composite Material,
2018
Old Dominion University
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 …
Detonation Synthesis Of Alpha-Variant Silicon Carbide,
2018
Missouri University of Science and Technology
Detonation Synthesis Of Alpha-Variant Silicon Carbide, Martin Langenderfer, Catherine E. Johnson, William Fahrenholtz, Vadym Mochalin
Mining Engineering Faculty Research & Creative Works
A recent research study has been undertaken to develop facilities for conducting detonation synthesis of nanomaterials. This process involves a familiar technique that has been utilized for the industrial synthesis of nanodiamonds. Developments through this study have allowed for experimentation with the concept of modifying explosive compositions to induce synthesis of new nanomaterials. Initial experimentation has been conducted with the end goal being synthesis of alpha variant silicon carbide (α-SiC) in the nano-scale. The α-SiC that can be produced through detonation synthesis methods is critical to the ceramics industry because of a number of unique properties of the material. Conventional …
Interface Structure And Deformation Mechanisms Of Mg/Nb Multilayers,
2018
University of Nebraska-Lincoln
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 …
Boro-Austempering Treatment Of Ductile Cast Irons,
2018
Universidade de São Paulo
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 …
Effects Of Automated Fiber Placement On High Strain Rate Compressive Response Of Advanced Composites,
2018
Old Dominion University
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) …
Energy Conversion System For Travelers (Ecost),
2018
Chulalongkorn University Demonstration Secondary School
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 …
Feco2o4 As An Anode Material For Lithium Ion Batteries,
2018
National Junior College
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 …
Radiation Effects In Apatite And High Entropy Alloy Under Energetic Ions And Electrons,
2018
Louisiana State University and Agricultural and Mechanical College
Radiation Effects In Apatite And High Entropy Alloy Under Energetic Ions And Electrons, Jianren Zhou
LSU Doctoral Dissertations
Radiation effects in apatite and high entropy alloy under energetic ions and electrons are studied in this doctoral dissertation to develop advanced crystalline ceramic waste forms and nuclear structural materials. Apatite is proposed as a ceramic waste form for the immobilization of radionuclides, but its performance is strongly affected by the irradiation of the incorporated radionuclides. It is thus important to understand the radiation effects in apatite structure and the underlying physics. Effects of chemical composition, grain size, interfacial structure, as well as radiation conditions on the microstructural evolution, phase transformation and damage mechanisms of apatite under alpha-decay and beta-decay …
Electronic Structure, Pore Size Distribution, And Sorption Characterization Of An Unusual Mof, {[Ni(Dpbz)][Ni(Cn)4]}N, Dpbz = 1,4-Bis(4-Pyridyl)Benzene,
2018
National Institute of Standards and Technology
Electronic Structure, Pore Size Distribution, And Sorption Characterization Of An Unusual Mof, {[Ni(Dpbz)][Ni(Cn)4]}N, Dpbz = 1,4-Bis(4-Pyridyl)Benzene, Winnie Wong-Ng, Izaak Williamson, Matthew Lawson, Daniel W. Siderus, Jeffrey T. Culp, Yu-S. Chen, Lan Li
Materials Science and Engineering Faculty Publications and Presentations
The monoclinic (Ni(L)[Ni(CN)4] (L= 1,4-Bis(4-pyridyl) benzene) compound (defined as Ni-dpbz) is a flexible metal organic framework which assumes a pillared structure with layers defined by 2D Ni[Ni(CN)4]n nets and dpbz ligands as pillars. The structure features an entrapped dpbz ligand that links between the open ends of four-fold Ni sites from two neighboring chains. This arrangement results in an unusual 5-fold pseudo square-pyramid environment for Ni and a significantly long Ni-N distance of 2.369(4) Å. Using Density Functional Theory calculations, the different bonding characteristics between the 5-fold and 6-fold Ni's were determined. We found that …
Design And Characterization Of Polymer Nanocomposites For Engineering Applications,
2018
Rowan University
Design And Characterization Of Polymer Nanocomposites For Engineering Applications, Joseph Richard Nalbach
Theses and Dissertations
Polymer nanocomposites represent an area of materials that can yield useful properties not achievable in bulk materials. Not only can they have such properties but also they can be relatively easy to generate. With dwindling fossil fuels there is an increased need for both new methods to harvest energy and to transport the captured energy more effectively. Two separate nanocomposite materials are created to support this work with dramatically different properties, both to aid in energy efficiency. The first is an energy harvesting foam to fully utilize the structural deformability of such a material. A dissolvable sugar scaffold is combined …
Co3(Hcoo)6@Rgo As A Promising Anode For Lithium Ion Batteries,
2018
State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, iChem (Collaborative Innovation Center of Chemistry for Energy Materials), Xiamen University, Xiamen 361005, China;
Co3(Hcoo)6@Rgo As A Promising Anode For Lithium Ion Batteries, Heng Jiang, Jing-Min Fan, Ming-Sen Zheng, Quan-Feng Dong
Journal of Electrochemistry
Metal–organic framework(MOF) is a kind of novel electrode materials for lithium ion batteries. Here, a composite material Co3(HCOO)6@rGO was synthesized for the first time by in situ loading of Co3(HCOO)6 on rGO (reduced oxide graphene) through a solution chemistry method. As an anode material for lithium ion batteries, it exhibited an excellent cycle stability as well as a large reversible capacity of 926 mAh·g-1 at a current density of 500 mA·g-1 after 100 cycles within the voltage range of 0.02 ~ 3.0 V vs. Li/Li+ with a good rate capability. …
Chemical Stability Investigations Of Catalyst Layer In Pemfc,
2018
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China; University of Chinese Academy of Sciences, Beijing 100039, China;
Chemical Stability Investigations Of Catalyst Layer In Pemfc, Yan-Yan Gao, Ming Hou, Yong-Yi Jiang, Dong Liang, Jun Ai, Li-Min Zheng
Journal of Electrochemistry
This work was intended to study the effect of free radicals on the chemical stability of catalyst layer via ex situ accelerated stress test (AST). Fenton reagent was used as the free radical provider in this research. Apart from the decomposition of Nafion in catalyst layer, the agglomerated Pt nanoparticles and the corroded carbon support were also observed after being treated in Fenton reagent for 100 h. Firstly, the existence of fluoride (F) ions evidenced the chemical decomposation of Nafion after being attacked by trace radical species, which was supported by the intensity decrease in the C-F stretching and vibration …
Aftershocks In Slowly Compressed Bulk Metallic Glasses: Experiments And Theory,
2018
University of Illinois at Urbana-Champaign
Aftershocks In Slowly Compressed Bulk Metallic Glasses: Experiments And Theory, Louis W. Mcfaul, Wendelin Wright, Xiaojun Gu, Jonathan T. Uhl, Karin A. Dahmen
Faculty Journal Articles
We observe two distinct interevent time patterns in the slip avalanches of compressed bulk metallic glasses (BMGs). Small slip avalanches cluster together in time, but large slip avalanches recur roughly periodically. We compare the timing patterns of BMG slip avalanches with timing patterns of earthquakes and with the predictions of a mean-field model. The time clustering of small avalanches is similar to the known time clustering of earthquake foreshocks and aftershocks.
Recent Progress For Fe-N-C Electrocatalysts In Alkaline Fuel Cells,
2018
College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China;
Recent Progress For Fe-N-C Electrocatalysts In Alkaline Fuel Cells, Xin Deng, Heng-Quan Chen, Ye Hu, Qing-Gang He
Journal of Electrochemistry
Fuel cells are highly recommended nowadays due to their intrinsic advantages such as high energy conversion efficiency, nearly no pollution, and convenient operation. With the development of anion exchange membrane, alkaline fuel cells have gone through a renaissance thanks to their superiorities such as faster reaction kinetics, wider choices for both fuels and electrocatalysts. It is essential to find an appropriate electrocatalyst for oxygen reduction reaction (ORR) to improve the performance of alkaline fuel cells. Further commercialization of the widely used Pt-based materials has suffered from disadvantages such as scarcity and high cost. As alternatives to largely investigated Pt-based materials, …
A Study Of Pulse Electrodeposition On Suppressing The Formation Of Lithium Dendrite,
2018
State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China;
A Study Of Pulse Electrodeposition On Suppressing The Formation Of Lithium Dendrite, Wen-Jun Guo, Zi-Qiong Li, Ruo-Hao Ke, Dong-Fang Niu, Heng Xu, Xin-Sheng Zhang
Journal of Electrochemistry
A pulse charge method was used to suppress the formation of lithium dendrite on the copper electrode in 0.5 mol·L-1 LiBr/propylene carbonate (PC) electrolyte. The surface variation of lithium deposition was investigated by scanning electron microscope and impedance measurement. The SEM test showed that the lithium dendrites were formed on the copper electrode during the traditional process of electrodeposition. However, the formed dendrite was suppressed by pulse charge method. The results of the impedance measurement confirmed that the pulse electrodeposition could suppress the dendrite under the optimized duty ratio (0.5). The long single pulse deposition time decreased the resistance …
Pt/G-C3N4 Nanosheet For Visible Light-Induced Enhancement Of The Activity For Formic Acid Electro-Oxidation,
2018
Institute of Advanced Chemical Power Sources, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China;School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China;
Pt/G-C3N4 Nanosheet For Visible Light-Induced Enhancement Of The Activity For Formic Acid Electro-Oxidation, Yong-Rong Sun, Chun-Yu Du, Guo-Kang Han, Ya-Jing Wang, Yun-Zhi Gao, Ge-Ping Yin
Journal of Electrochemistry
By using graphitic carbon nitride nanosheet (g-C3N4 nanosheet) as a support,Pt/g-C3N4 nanosheet catalyst was fabricated by microwave assisted polylol process. The nanoparticles size,composition,structure and optical properties of Pt/g-C3N4 nanosheet were characterized by TEM,XRD,XPS and UV-Vis diffuse reflectance spectroscopy. Comparing with the catalytic activities toward formic acid electro-oxidation under dark and visible light illumination,the superior activity of Pt/g-C3N4 nanosheet catalyst was achieved under visible light illumination. This visible light-driven enhancement in the formic acid performance could be attributed to the plasmon-induced electron-hole separation on g-C3N4 with …
Preparation And Electrochemical Performance Of Ag-Tio2-Mno2 Composites,
2018
Beijing Key Laboratory for Green Catalysis and Separation, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China;
Preparation And Electrochemical Performance Of Ag-Tio2-Mno2 Composites, Ling-Xiao Zhang, Hui-Hui Zhao, Li-Juan Zhang, Yu Fu
Journal of Electrochemistry
The silver-titanium dioxide co-modified manganese dioxide (Ag-TiO2-MnO2) cathode material was prepared through high temperature solid state reaction. The microstructure, phase composition and electrochemical performance of the prepared samples were characterized by X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectroscopy (XPS), Energy-dispersive X-ray spectroscopy (EDS), Cyclic voltammetry (CV), galvanostatic discharge and electrochemical impedance spectroscopy (EIS). Results showed that the unmodified and Ag-TiO2 modified MnO2 samples both exhibited β-MnO2 structurebut with different morphologies. The EDS mapping results revealed that Ag was uniformly dispersed on the surface of …
