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2013

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Articles 1 - 30 of 520

Full-Text Articles in Materials Science and Engineering

Localized Corrosion Behavior Of Sensitized 304 Stainless Steel By Scanning Reference Electrode Technique, Chen-Qing Ye, Rong-Gang Hu, Rui-Qing Hou, Xiao-Ping Wang, Rong-Gui Du, Chang-Jian Lin Dec 2013

Localized Corrosion Behavior Of Sensitized 304 Stainless Steel By Scanning Reference Electrode Technique, Chen-Qing Ye, Rong-Gang Hu, Rui-Qing Hou, Xiao-Ping Wang, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

Based on a home-built setup of scanning reference electrode technique, and combined with conventional electrochemical measurements, the localized corrosion behavior of sensitized 304 stainless steel (304ss) had been investigated in this work. The results showed that, the non-sensitized 304ss or 304ss sensitized at 550 oC was susceptible to pitting; while 304ss sensitized at 650 oC or 750 oC suffered severe intergranular corrosion in 10% FeCl3 solution.

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Application Of Synchrotron Radiation Based Electrochemical In-Situ Techniques To Study Of Electrode Materials For Lithium-Ion Batteries, Zheng-Liang Gong, Wei Zhang, Dong-Ping Lv, Xiao-Gang Hao, Wen Wen, Zheng Jiang, Yong Yang Dec 2013

Application Of Synchrotron Radiation Based Electrochemical In-Situ Techniques To Study Of Electrode Materials For Lithium-Ion Batteries, Zheng-Liang Gong, Wei Zhang, Dong-Ping Lv, Xiao-Gang Hao, Wen Wen, Zheng Jiang, Yong Yang

Journal of Electrochemistry

Due to its merits of high brightness and high intensity, high level of polarization and wide tunability in energy, etc., synchrotron radiation technique provides an unique platform for analysis of the relationship among composition–structure–performance of materials for lithium ion batteries, especially for in-situ, real time dynamic investigation of the electrochemical reaction mechanism, aging process and failure mechanism during charge-discharge cycling. In this paper, we review the latest developments in application of synchrotron based electrochemical in-situ experimental methods to studies of lithium ion batteries. The paper mainly focuses on the application of electrochemical in-siu XRD and XAFS techniques to the investigations …

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Controllable Synthesis Of Dispersed Spherical Fe3O4 Nanoparticles As Lithium-Inserted Materials, Hong-Li Zou, Wei-Shan Li Dec 2013

Controllable Synthesis Of Dispersed Spherical Fe3O4 Nanoparticles As Lithium-Inserted Materials, Hong-Li Zou, Wei-Shan Li

Journal of Electrochemistry

Dispersed spherical Fe3O4 nanoparticles were synthesized by a hydrothermal method. The influences of odecyl trimethyl ammonium bromide (DTAB) concentration on the morphology and particle size of the as-prepared Fe3O4 were studied. Electrochemical performance of the as-prepared sample as anode materials of lithium ion battery was investigated. It is found that the as-prepared sample exhibits superior rate performance and cycle performance. The nano-sized materials provide structural stability and favor the transfer of lithium ions.

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Study On Hydrogen Bubble Template Fabrication Of Porous Biomaterials Coatings By Electrochemically Induced Deposition, Hui Wang, Chang-Jian Lin, Ren Hu, Ke-Qin Zhang, Hong-Ping Duan, Xiang Dong Dec 2013

Study On Hydrogen Bubble Template Fabrication Of Porous Biomaterials Coatings By Electrochemically Induced Deposition, Hui Wang, Chang-Jian Lin, Ren Hu, Ke-Qin Zhang, Hong-Ping Duan, Xiang Dong

Journal of Electrochemistry

So far, the pore architecture in biomaterials plays a critical role on the cell response and integration between the biomaterials and implanted environment. In this study, porous calcium phosphate (CaP) coatings and CaP/protein composite coatings have been successfully constructed on titanium substrate by using an electrochemically induced deposition technique. The shape, size and pliability of CaP crystals are controlled by electrolyte concentration, temperature, current density, time and protein additive in preparing process. In addition, the formation mechanism of the porous structure is discussed based on the “hydrogen bubble template” model. It demonstrates that the growth velocity of CaP crystals should …

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An Investigation On The Solid Electrolyte Interphase Of Silicon Anode For Li-Ion Batteries Through Force Curve Method, Jie-Yun Zheng, Hao Zheng, Rui Wang, Hong Li, Li-Quan Chen Dec 2013

An Investigation On The Solid Electrolyte Interphase Of Silicon Anode For Li-Ion Batteries Through Force Curve Method, Jie-Yun Zheng, Hao Zheng, Rui Wang, Hong Li, Li-Quan Chen

Journal of Electrochemistry

Non-aqueous electrolyte has been widely used in commercial Li-ion batteries. Optimized choices are proceeding among the various types of salts and solvents in an effort to achieve higher performance of electrolyte. However, the electrolyte will be reduced in low potential and the reductive product will be deposited on the surface of anode to form a passivating layer, solid electrolyte interphase (SEI). Herein an atomic force microscopy (AFM) based method was introduced to study the structure and mechanical property of SEI on silicon thin film anode during the first cycle. Silicon has been known as the most potential candidate anode for …

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Preparation And Electrochemical Properties Of Flake-Like Liv3O8 By Soft Template Assisted Sol-Gel Method As Anode Material For Aqueous Li-Ion Battery, Shuai Tan, Dan Sun, Hai-Yan Wang, Tian-Li Hou, Zhong-Xing Xiao, You-Gen Tang Dec 2013

Preparation And Electrochemical Properties Of Flake-Like Liv3O8 By Soft Template Assisted Sol-Gel Method As Anode Material For Aqueous Li-Ion Battery, Shuai Tan, Dan Sun, Hai-Yan Wang, Tian-Li Hou, Zhong-Xing Xiao, You-Gen Tang

Journal of Electrochemistry

Composite electrode of CuF2/MoO3/C was fabricated through high energy mechanical milling. The properties of CuF2/MoO3/C were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (TEM), galvanostatic charge-discharge measurements, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that the grain sizes of CuF2 and MoO3 after milling were 200 ~ 300 nm, and the initial discharge capacity of CuF2/MoO3/C was 647 mAh·g-1 at room temperature and at a current density of 10 mAh·g-1. However, the …

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Synthesis And Electrochemical Performance Of Nano Licopo4 By Polyol Method, Fei Wang, Yang Jun Dec 2013

Synthesis And Electrochemical Performance Of Nano Licopo4 By Polyol Method, Fei Wang, Yang Jun

Journal of Electrochemistry

High potential LiCoPO4 cathode material was synthesized by polyol method. Carbon layer of ca. 3 nm thick was coated on the LiCoPO4 surfaces by chemical vapor deposition from methylbenzene. Crystalline structure, morphology and electrochemical performance of the sample were studied by XRD, SEM, TEM, CV and galvanostatic charge/discharge curve. The synthesized material via polyol method showed a pure phase of LiCoPO4. The LiCoPO4/C electrode delivered a high discharge capacity of 132 mAh·g-1 and maintained 78% of the initial capacity after 50 cycles at 0.1C rate. The two-step extraction/insertion behavior of Li+ in …

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Electrochemical Na-Storage Materials And Their Applications For Na-Ion Batteries, Jiang-Feng Qian, Xue-Ping Gao, Han-Xi Yang Dec 2013

Electrochemical Na-Storage Materials And Their Applications For Na-Ion Batteries, Jiang-Feng Qian, Xue-Ping Gao, Han-Xi Yang

Journal of Electrochemistry

Oncoming large scale electric energy storage (EES) requires battery systems not only to have sufficient storage capacity but also to be cost-effective and environmentally friendly. Li-ion batteries for widespread EES applications may be limited due to the constraint of global lithium resource. From the considerations of available resources and environmental impact, Na-ion batteries have potential advantages as next generation secondary batteries and an alternative to Li-ion batteries. However, in the present state of the art, the Na-storage cathodes reported so far are still deficient both in energy density and power capability, while the carbon and alloy anodes for Na-ion batteries …

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Cmk-3/Sulfur Composite (CXSY) And Room-Temperature Na/S Battery, Qing Zhao, Yu-Xiang Hu, Kai Zhang, Li-Jiang Wang, Zhan-Liang Tao, Jun Chen Dec 2013

Cmk-3/Sulfur Composite (CXSY) And Room-Temperature Na/S Battery, Qing Zhao, Yu-Xiang Hu, Kai Zhang, Li-Jiang Wang, Zhan-Liang Tao, Jun Chen

Journal of Electrochemistry

A series of ordered mesoporous carbon (CMK-3)/sulfur composite (CxSy) with different sulfur contents were synthesized via a melt-diffusion method. XRD, Raman, BET, SEM, and TEM techniques were used to characterize the structure and morphology of the as-prepared composite. The electrochemical performance of CMK-3/sulfur composite as the electrode of Na/S battery was tested at room temperature. Cyclic voltammograms show that one obvious reduction peak was located at about 1.61V, which is corresponding to the formation of Na2Sx (x=2~5), while two oxidation peaks were displayed at about 1.82V and 1.95V, which are belonging to the …

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Preparation Of The Particle Size Controllable Lifepo4/C And Its Electrochemical Profile Characterization, Ming-E Wang, Jing-Yuan Liu, Meng-Yan Hou, Yong-Yao Xia Dec 2013

Preparation Of The Particle Size Controllable Lifepo4/C And Its Electrochemical Profile Characterization, Ming-E Wang, Jing-Yuan Liu, Meng-Yan Hou, Yong-Yao Xia

Journal of Electrochemistry

We adopted an effective route to prepare the particle size controllable core-shell structure carbon-coated LiFePO4 from different sized FePO4 precursors, varying from 80 nm, 200 nm and 1 μm by an in situ polymerization method integrated with a surface modification technology. The discharge capacities of the three sized LiFePO4/C are, respectively, 162 mAh·g-1, 142 mAh·g-1 and 92 mAh·g-1 at 0.1C rate. The nano-sized LiFePO4-a/C (80 nm) delivers a discharge capacity as large as 100 mAh·g-1 even at 30C, while the macroscopic LiFePO4-c/C (1 μm) exhibits a much …

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Surface Composition Structure And Electrochemical Performance Of Aluminum Doped Lifepo4, Huai-Fang Shang, Wei-Feng Huang, Wang-Sheng Hu, Ding-Guo Xia, Zi-Yu Wu Dec 2013

Surface Composition Structure And Electrochemical Performance Of Aluminum Doped Lifepo4, Huai-Fang Shang, Wei-Feng Huang, Wang-Sheng Hu, Ding-Guo Xia, Zi-Yu Wu

Journal of Electrochemistry

Despite there are many successful reports about the preparation of electrode materials with surface coating for lithium ion batteries, the study in surface self-coating of cathode materials using segregation of doping elements and their electrochemical properties is still very rare. The LiFePO4 particles with rich-Al on the surface were synthesized by one step solvothermal route. TEM results demonstrated that the surface of the obtained LiFePO4 particles was well-covered by the amorphous coating. The soft X-ray absorption spectroscopy (XAS) and Auger electron spectroscopy (AES) component analyses revealed that the amorphous coating was composed of LiFe1-xAlxPO …

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Preparation And Electrochemical Properties Of Amorphous Znsno3/C By Hydrothermally Carbonization Method, Guo-Qing Fang, Rui-Xue Zhang, Wei-Wei Liu, Bing-Bo Xia, Hong-Dan Sun, Hai-Bo Wang, Jing-Jing Wu, Shinko Kaneko, De-Cheng Li Dec 2013

Preparation And Electrochemical Properties Of Amorphous Znsno3/C By Hydrothermally Carbonization Method, Guo-Qing Fang, Rui-Xue Zhang, Wei-Wei Liu, Bing-Bo Xia, Hong-Dan Sun, Hai-Bo Wang, Jing-Jing Wu, Shinko Kaneko, De-Cheng Li

Journal of Electrochemistry

The amorphous ZnSnO3@C composite was synthesized via a simple glucose hydrothermal and subsequent carbonization approach. The structure, morphology and electrochemical property of the composite were characterized by XRD, TEM and electrochemical measurements. Compared to bare ZnSnO3, the ZnSnO3/C composite exhibited markedly enhanced lithium storage property and cycle performance, delivering a reversible capacity of 659 mAh·g-1 after 100 cycles at a current density of 100 mA·g-1.

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Synthesis And Electrochemical Property Of Li2Fesio4/C Cathode Material By Solid State Method, Jiao-Li Sun, Zhi-Jiao Chen, Yi-Xiao Li, Hu Cheng Dec 2013

Synthesis And Electrochemical Property Of Li2Fesio4/C Cathode Material By Solid State Method, Jiao-Li Sun, Zhi-Jiao Chen, Yi-Xiao Li, Hu Cheng

Journal of Electrochemistry

Li2FeSiO4/C cathode material was synthesized using Li2SiO3 and FeC2O4 as raw materials by solid state method. The structure and morphology of the material were characterized by XRD and SEM. The electrochemical properties of the material were studied by constant-current cyclic testing. The results show that Li2FeSiO4/C has a good electrochemical performance. The first discharge capacity of Li2FeSiO4/C cathode material at 30oC reached 167 mAh∙g-1 when cycled at 10 mA∙g-1 between 1.5 and 4.8 V.

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Aqueous Solution-Evaporation Route Synthesis And Phase Structural Research Of The Li-Rich Cathode Li1.23Ni0.09Co0.12Mn0.56O2 By In-Situ Xrd, Chong-Heng Shen, Shou-Yu Shen, Zhou Lin, Xiao-Mei Zheng, Hang Su, Ling Huang, Jun-Tao Li, Shi-Gang Sun Dec 2013

Aqueous Solution-Evaporation Route Synthesis And Phase Structural Research Of The Li-Rich Cathode Li1.23Ni0.09Co0.12Mn0.56O2 By In-Situ Xrd, Chong-Heng Shen, Shou-Yu Shen, Zhou Lin, Xiao-Mei Zheng, Hang Su, Ling Huang, Jun-Tao Li, Shi-Gang Sun

Journal of Electrochemistry

The Li-rich Li1.23Ni0.09Co0.12Mn0.56O2 material was synthesized via aqueous solution-evaporation route. The structure and morphology of the material were characterized by means of XRD and SEM. The results indicated that the single particle of the product was polygonal with the size of 330 nm and the structure was layered solid solution with a certain amount of Li2MnO3. Electrochemical tests showed that the first discharge capacity of the Li-rich layered material was 250.8 mAh·g-1 at 0.1C, the capacity retention was 86.5% after 40 cycles. Through in-situ XRD study …

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Free-Troposphere Ozone And Carbon Monoxide Over The North Atlantic For 2001-2011, Aditya Kumar, S. Wu, M. F. Weise, R. Honrath, R. C. Owen, D. Helmig, L. Kramer, M. Val Martin, Q. Li Dec 2013

Free-Troposphere Ozone And Carbon Monoxide Over The North Atlantic For 2001-2011, Aditya Kumar, S. Wu, M. F. Weise, R. Honrath, R. C. Owen, D. Helmig, L. Kramer, M. Val Martin, Q. Li

Michigan Tech Publications, Part 1

In situ measurements of carbon monoxide (CO) and ozone (O3) at the Pico Mountain Observatory (PMO) located in the Azores, Portugal, are analyzed together with results from an atmospheric chemical transport model (GEOS-Chem) and satellite remote sensing data (AIRS (Atmospheric Infrared Sounder) for CO, and TES (Tropospheric Emission Spectrometer) for O3) to examine the evolution of free-troposphere CO and O3 over the North Atlantic for 2001-2011. GEOS-Chem captured the seasonal cycles for CO and O3 well but significantly underestimated the mixing ratios of CO, particularly in spring. Statistically significant (using a significance level of 0.05) decreasing trends were found for …

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Enhanced Dna Sensing Via Catalytic Aggregation Of Gold Nanoparticles, Herbert M. Huttanus, Elton Graugnard, Bernard Yurke, William B. Knowlton, Wan Kuang, William L. Hughes, Jeunghoon Lee Dec 2013

Enhanced Dna Sensing Via Catalytic Aggregation Of Gold Nanoparticles, Herbert M. Huttanus, Elton Graugnard, Bernard Yurke, William B. Knowlton, Wan Kuang, William L. Hughes, Jeunghoon Lee

Materials Science and Engineering Faculty Publications and Presentations

A catalytic colorimetric detection scheme that incorporates a DNA-based hybridization chain reaction into gold nanoparticles was designed and tested. While direct aggregation forms an inter-particle linkagefrom only one target DNA strand, catalytic aggregation forms multiple linkages from a single target DNA strand. Gold nanoparticles were functionalized with thiol-modified DNA strands capable of undergoing hybridization chain reactions. The changes in their absorption spectra were measured at different times and target concentrations and compared against direct aggregation. Catalytic aggregation showed a multifold increase in sensitivity at low target concentrations when compared to direct aggregation. Gelelectrophoresis was performed to compare DNA hybridization reactions …

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Nd–Fe–B Nanoparticles Through Surfactant Assisted Mechanical Milling And Alloy Design, Jordann M. Bornhoft Dec 2013

Nd–Fe–B Nanoparticles Through Surfactant Assisted Mechanical Milling And Alloy Design, Jordann M. Bornhoft

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

Surfactant-assisted mechanical milling has been used to produce discrete nanoparticles of both Nd-Fe-B and Sm-Co amenable for bottom-up production of nanostructured or nanocomposite permanent magnets. However, in Nd-Fe-B the comminution of the material proceeds by transgranular fracture, which influences both the morphology of the nanoparticles and the magnetic properties. This paper utilizes alloy design to alter the fracture behavior from transgranular fracture to intergranular fracture. Nd-rich Nd2Fe14B alloys were produced by melt spinning in an overquenched state. The melt spun ribbons were annealed at 700°C and 800°C to ensure complete crystallization and to form different grain …

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Microgrid Development Using A Grid Tie Inverter, Hartono Budi Santoso, Budiyanto Budiyanto Dec 2013

Microgrid Development Using A Grid Tie Inverter, Hartono Budi Santoso, Budiyanto Budiyanto

Makara Journal of Technology

The use of renewable energy sources (RES), especially photovoltaic (PV), to meet the demand of electrical energy has been getting a great deal of attention as an alternative solution to electrical energy deficit problems. RES are being applied in power systems in a variety of configurations including microgrid systems. One of the characteristics of a microgrid is capability to supplying power to grid when there is an excess power to supply local load. This research examines the chances of saving power consumption from grid using power converters grid tie inverter (GTI) in a microgrid configuration. The test is done by …

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Surface Treatment Of Fly Ash For Improving The Tensile Strength Of Fly Ash/Unsaturated Polyester Composites, Sugiman Sugiman, Paryanto Dwi Setyawan Dec 2013

Surface Treatment Of Fly Ash For Improving The Tensile Strength Of Fly Ash/Unsaturated Polyester Composites, Sugiman Sugiman, Paryanto Dwi Setyawan

Makara Journal of Technology

The paper presents the surface treatment of fly ashes using acid and alkali solution on the tensile strength of the fly ash/unsaturated polyester (UP) composites. Sulfuric acid (H2SO4), hydrofluoric acid (HF) and sodium hydroxide (NaOH) solution with concentration of 0%, 5%, 10%, 15%, and 20% (by weight) were used for surface treatment of fly ashes. Generally, the tensile strength of the treated fly-ash/UP composites shows a significant increase compared to the untreated fly ash. Of all surface treatments studied, the optimum tensile strength was obtained at a concentration of 10%. At this concentration, at a fly ash content of 30% …

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Recycling Roof Tile Waste Material For Wall Cover Tiles, Ambar Mulyono, Silfia Mona Aryani, Joko Lulut Dec 2013

Recycling Roof Tile Waste Material For Wall Cover Tiles, Ambar Mulyono, Silfia Mona Aryani, Joko Lulut

Makara Journal of Technology

Prior research on roof tile waste treatment has attempted to find the appropriate technology to reuse old roof tile waste by create wall cladding materials from it. Through exploration and experimentation, a treatment method has been discovered to transform the tile fragments into artificial stone that resembles the shape of coral. This baked clay artificial stone material is then processed as a decorative element for vertical surfaces that are not load-bearing, such as on the interior and exterior walls of a building. Before applying the fragments as wall tiles, several steps must be taken: 1) Blunting, which changes the look …

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Synthesis Of Tungsten Oxide Nanowires Onto Ito Glass Using T-Cvd, Tomy Abuzairi, Bohr-Ran Huang, Tzu-Ching Lin Dec 2013

Synthesis Of Tungsten Oxide Nanowires Onto Ito Glass Using T-Cvd, Tomy Abuzairi, Bohr-Ran Huang, Tzu-Ching Lin

Makara Journal of Technology

Tungsten oxide is an n-type semiconductor with interesting physical and chemical properties that make it suitable for various technological applications. Tungsten oxide nanowires were synthesized not only at low temperature but also without the use of any catalysts. The tungsten oxide nanowires were synthesized at 550 °C with tungsten layers onto the ITO glass using thermal chemical vapor deposition (T-CVD). The SEM image shows that the tungsten oxide nanowires are effectively grown with the 200 nm tungsten film. The Raman spectra shoulder at ~690 cm-1 proves the synthesized of tungsten oxide nanowires.

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Semiconductor Thermal Neutron Detector, Toru Aoki, Aki Miyake, Takayuki Nakano, Akifumi Koike, Hisashi Morii, Hidenori Mimura Dec 2013

Semiconductor Thermal Neutron Detector, Toru Aoki, Aki Miyake, Takayuki Nakano, Akifumi Koike, Hisashi Morii, Hidenori Mimura

Makara Journal of Technology

The CdTe and GaN detector with a Gd converter have been developed and investigated as a neutron detector for neutron imaging. The fabricated Gd/CdTe detector with the 25 mm thick Gd was designed on the basis of simulation results of thermal neutron detection efficiency and spatial resolution. The Gd/CdTe detector shows the detection of neutron capture gamma ray emission in the 155Gd(n, g)156Gd, 157Gd(n, g)158Gd and 113Cd(n, g)114Cd reactions and characteristic X-ray emissions due to conversion-electrons generated inside the Gd film. The observed efficient thermal neutron detection with the Gd/CdTe detector shows its promise in neutron radiography application. Moreover, a …

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Radiation Characteristics Of A Planar Strip Dipole Antenna And A Slot Dipole Antenna For Thz Applications, Catur Apriono, Eko Tjipto Rahardjo Dec 2013

Radiation Characteristics Of A Planar Strip Dipole Antenna And A Slot Dipole Antenna For Thz Applications, Catur Apriono, Eko Tjipto Rahardjo

Makara Journal of Technology

The development of a THz system often requires a device that is used to radiate or detect THz waves. One way to fulfill this requirement is to use an antenna. Therefore, we need to consider the radiation characteristics of an antenna working in the THz region. In this paper, we present simulation study of two dipole antennas, i.e. a planar strip dipole antenna and a slot dipole antenna. The simulation results show that a planar strip dipole antenna has a better radiation efficiency (more than 95%) compared to the slot dipole. It also shows that an efficiency of more than …

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The Effect Of Pressing Temperature And Time On The Quality Of Particle Board Made From Jatropha Fruit Hulls Treated In Acidic Condition, Apri Heri Iswanto, Fauzi Febrianto, Yusuf Sudo Hadi, Surdiding Ruhendi, Dede Hermawan Dec 2013

The Effect Of Pressing Temperature And Time On The Quality Of Particle Board Made From Jatropha Fruit Hulls Treated In Acidic Condition, Apri Heri Iswanto, Fauzi Febrianto, Yusuf Sudo Hadi, Surdiding Ruhendi, Dede Hermawan

Makara Journal of Technology

The high of pH of jatropha fruit hulls causes the negative properties of particleboard made from this material. Adjusting the particle acidity and pressing conditions (temperature and time) is among the technical modifications available to improve this particleboard’s properties. Particle acidity has been adjusted in a previous research project, and immersing the particles in acetic acid was found to be the best treatment in this preliminary research. In order to improve the particleboard’s properties, an experiment was conducted to determine the best pressing temperature and time. The objective of the research was to evaluate the influence of pressing temperature and …

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Sio2-Included Cesium Polyoxotungstate Catalysts For Oxidation, W Trakarnpruk, W Kanjina Dec 2013

Sio2-Included Cesium Polyoxotungstate Catalysts For Oxidation, W Trakarnpruk, W Kanjina

Journal of Metals, Materials and Minerals

SiO2-included cesium polyoxotungstate catalysts were synthesized by a sol-gel method and characterizied by FTIR, XRD and N2 adsorption isotherms. XRD patterns prove that the cesium polyoxotungstate is uniformly dispersed in the silica network. The catalysts were used in oxidation of cyclohexane with H2O2. The products are cyclohexanol and cyclohexanone. The catalysts prepared by using a copolymer surfactant show higher surface area and exhibit higher activity. These catalysts are truly heterogeneous and can be reused at least 3 times.

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Corrosion Behavior Of Tialn Film On Aisi 4140 Steel, T Wongpinij, P Wongpanya, C Euaruksakul, P Photongkam, N Witit-Anun Dec 2013

Corrosion Behavior Of Tialn Film On Aisi 4140 Steel, T Wongpinij, P Wongpanya, C Euaruksakul, P Photongkam, N Witit-Anun

Journal of Metals, Materials and Minerals

The corrosion behavior of uncoated and TiAlN coated on AISI 4140 steel were studied by an electrochemical technique in 3.5 wt% NaCl solution at pH value of 2, 7 and 10 at room temperature. The corrosion potential (Ecorr), pitting potential (Epit), corrosion rate (Rmmy) and passive region in polarization curves were analyzed and compared.After electrochemical testing, samples surface was characterized by scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and X-ray photoemission electron microscopy (X-PEEM). The results indicated that the TiAlN coated samples yielded better corrosion resistance than the uncoated samples. The coated samples had lower corrosion rate …

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Dolomite Stabilized Zirconia For Refractory Application : Part-I Phase Analysis, Densification Behavior And Microstructure Of Partial Stabilized Zirconia, R Prasad Rana, P Kumar, A Suvrajit Bal Dec 2013

Dolomite Stabilized Zirconia For Refractory Application : Part-I Phase Analysis, Densification Behavior And Microstructure Of Partial Stabilized Zirconia, R Prasad Rana, P Kumar, A Suvrajit Bal

Journal of Metals, Materials and Minerals

In the continuous casting of steel, Zircon and Zirconia based products are used due to its high thermal stability, excellent erosion resistance, self-opening, consistent casting speed and resistance to oxygen lancing during casting for removal of inclusion clogging and to streamline the flow. Higher casting sequences of molten steel CaO or MgO stabilized zirconia nozzles were being used and for industrial application point of view, dolomite stabilized zirconia (DSZ) could be a better substitute for the stabilization of zirconia. DSZ samples were prepared having 3,4,5,6 and 7 mole % of dolomite by solid state route using high purity monoclinic zirconia …

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Effect Of Heat Treatment On Phase Transformation Of Tio2 And Its Reflectance Properties, K Archaapinun, N Witit-Anun, P Visuttipitukul Dec 2013

Effect Of Heat Treatment On Phase Transformation Of Tio2 And Its Reflectance Properties, K Archaapinun, N Witit-Anun, P Visuttipitukul

Journal of Metals, Materials and Minerals

Titanium dioxide (TiO2) anti reflection coating film applied for solar cell application, gains more interest due to the insufficient energy problems today. Titanium dioxide can be found in several forms, and the most stable phase is rutile. This research aims to study effect of heat treatment on phase transformation of TiO2 and its effect on reflectance property. Titanium dioxide film was coated on silicon wafer by DC magnetron sputtering to obtain 190 nm and 420 nm thicknesses. Then, it was heat treated at 900C for 1 and 4 hours under ambient atmosphere. Phases and surface morphologies before and after heat …

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Mineralogical Characterization Of Pozuzo District's Soils Through Physical Techniques, M L Cerón Loayza, J B. Cabrejos, F Reyes Navarro Dec 2013

Mineralogical Characterization Of Pozuzo District's Soils Through Physical Techniques, M L Cerón Loayza, J B. Cabrejos, F Reyes Navarro

Journal of Metals, Materials and Minerals

We introduce a study on soils in three different fields of plantations in Pozuzo District, Oxapampa province, Peru. Two of the fields are cultivated and the third one has a degradation problem. In situ, in all, we collected 29 samples in the three plantations. We utilized analytical and physical techniques, namely, energy dispersive X-ray fluorescence, X-ray diffractometry, and transmission Msbauer spectroscopy; we complemented our research with a physical-chemical analysis to determine texture, pH, content of organic matter and cation interchange capacity. For all analyzed samples, the results of the analysis by energy dispersive X-ray fluorescence show the presence of the …

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Friction And Wear Of Polytetrafluoroethylene/Graphene Oxide Composite Thin Films, Justin Kyle Carter Dec 2013

Friction And Wear Of Polytetrafluoroethylene/Graphene Oxide Composite Thin Films, Justin Kyle Carter

Graduate Theses and Dissertations

Polytetrafluoroethylene (PTFE) is a commonly used solid lubricant due to its low coefficient of friction and chemical inertness. As a polymer, PTFE suffers from high wear and low adhesion to substrates limiting its use as a thin film. Thin PTFE films are ideal candidates for solid lubrication in micro-machines and bearing applications. The main goal of this work is to enhance the durability of thin PTFE films through the addition of few layered graphene oxide (GO) as filler. In order to address adhesion issues, the addition of an adhesive layer of polydopamine (PDA) between stainless steel substrates and thin PTFE …

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