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Articles 23551 - 23580 of 27383

Full-Text Articles in Engineering

Preparation Of Polyaniline/Polyester Conductive Fabric Via In-Situ Polymerization, Fang Na, Wei Wang Nov 2009

Preparation Of Polyaniline/Polyester Conductive Fabric Via In-Situ Polymerization, Fang Na, Wei Wang

Journal of Electrochemistry

The formation of PANI coating on the surface of PET fiber and fabric was obtained by in-situ polymerization method.The coating′s thickness was about 1～2 μm.Orthogonal test methodology was used to analyze the main factors of preparation of PANI / PET conductive fabric.The effects of the aniline monomer concentration,oxidant: aniline molar ratio,doping acid concentration and types,reaction time on the conductivities of the fabric were studied.The structure of the polymer were characterized by SEM,FTIR and XRD.The results indicated that there was uniform and continuous polyaniline film on the surface of polyester fabric.The contents of oxidation and reduction of polyaniline molecular chain structure …

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Progresses In Electrocatalysis Of Nanomaterials—Tuning The Surface Structure And Property Of Electrocatalysts, Yan-Xia Jiang, Na Tian, Zhi-You Zhou, Sheng-Pei Chen, Shi-Gang Sun Nov 2009

Progresses In Electrocatalysis Of Nanomaterials—Tuning The Surface Structure And Property Of Electrocatalysts, Yan-Xia Jiang, Na Tian, Zhi-You Zhou, Sheng-Pei Chen, Shi-Gang Sun

Journal of Electrochemistry

The property of an electrocatalyst depends strongly on its surface structure.The study of surface structure-catalytic functionality is the base of design and preparation of electrocatalysts of high activity,high stability and high selectivity at microstructure level.In this paper,based mainly on our results concering hydrogen and oxygen adsorption-desorption,ethylene glycol oxidation and CO2 reduction,the research progresses in tuning the surface structure and property of electrocatalysts are summarized.This paper overviews firstly the cyclic voltammetric characteristics,electrocatalytic properties of platinum single crystal planes lying on different crystallographic zones of the unit stereographic triangle of face-centered cubic(fcc) metals.Next,the innovation of electrochemical methods to control the surface …

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Electrooxidation Of Formic Acid On Pd-Ni Alloy Film Electrode-The Effect Of Dealloying, Chao Wang, Fei-Fei Shi, Jin-Yi Wang, Han-Xuan Zhang, Wen-Bin Cai Nov 2009

Electrooxidation Of Formic Acid On Pd-Ni Alloy Film Electrode-The Effect Of Dealloying, Chao Wang, Fei-Fei Shi, Jin-Yi Wang, Han-Xuan Zhang, Wen-Bin Cai

Journal of Electrochemistry

A Pd-Ni alloy film was electrodeposited on Au disc electrode at a constant potential from a weakly basic bath containing PdCl2,NiSO4 and ethylenediamine.The as-deposited film was then subjected to potential cycling in a perchloric acid solution for surface dealloying treatment.The dealloyed Pd-Ni film electrode was examined for the electrocatalytic oxidation of formic acid,and compared with the as-deposited one as well as a Pd film electrode.The FE-SEM and electrochemical measurements on the Pd-Ni films revealed that the dealloying treatment caused a surface roughening and an increase in specific surface reaction area.The ICP-AES and XPS analyses demonstrated that the …

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Electrocatalysis In Polymer Electrolyte Membrane Fuel Cells, Li Li, Si-Guo Chen, Xue-Qiang Qi, Yao-Qiong Wang, Meng-Bo Ji, Lan-Lan Li, Zi-Dong Wei Nov 2009

Electrocatalysis In Polymer Electrolyte Membrane Fuel Cells, Li Li, Si-Guo Chen, Xue-Qiang Qi, Yao-Qiong Wang, Meng-Bo Ji, Lan-Lan Li, Zi-Dong Wei

Journal of Electrochemistry

This review presents the study of Chongqing University in electrocatalysis for polymer electrolyte membrane fuel cells(PEMFCs).Based on the understanding to the performance degradation of PEMFCs' catalysts,the university has being concentrated on how to increase the activity,stability and utility of noble metal catalysts.It covers the molecular design of near-surface alloy catalysts for improvement of activity to oxygen reduction reaction(ORR) and resistance to foreign poison species,selective deposition of Pt on the so-called "three-phase interface" for a high Pt utility,and invention of anti-flooding electrode against water flooding in the catalyst layer of the membrane assemble electrode(MEA),and so on.The catalytic mechanism of electrode reactions …

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Highly Durable Pt/Ruo2/C Catalyst For The Cathode Of Direct Methanol Fuel Cells, Chun-Yu Du, Tao Dong, Ge-Ping Yin, Peng-Fei Shi Nov 2009

Highly Durable Pt/Ruo2/C Catalyst For The Cathode Of Direct Methanol Fuel Cells, Chun-Yu Du, Tao Dong, Ge-Ping Yin, Peng-Fei Shi

Journal of Electrochemistry

Instability of the carbon-supported Pt(Pt/C) catalyst at the cathode is one of the key technical challenges for the development of Direct Methanol Fuel Cells(DMFCs).In this paper,an efficient approach to enhancing the stability of the cathode catalyst was explored by designing and synthesizing a novel nanocomposite support,RuO2 coated carbon black(RuO2/C).Firstly,a wet chemical method was employed to synthesize the RuO2/C nanocomposite,from which Pt/RuO2/C catalyst was further prepared by a microwave method.The morphology and crystalline structure of the RuO2/C support and Pt/RuO2/C catalyst were then characterized by TEM and XRD.Finally,the electrochemical performance …

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Synthesis And Electrocatalytic Properties Of Ni-Pd/C Catalysts With Pd-Enriched Surface, Yu-Mei Chen, Zhi-Xiu Liang, Sheng-Li Chen Nov 2009

Synthesis And Electrocatalytic Properties Of Ni-Pd/C Catalysts With Pd-Enriched Surface, Yu-Mei Chen, Zhi-Xiu Liang, Sheng-Li Chen

Journal of Electrochemistry

The Ni-Pd alloy catalysts with Pd-enriched surface were synthesized through a modified polyol process.The synthesized materials were investigated by XRD and electrochemical methods,and tested as electrocatalysts for CH3OH-tolerant oxygen reduction.The results indicated that the synthesized Ni-Pd nanoparticles possess multiple phases containing Pd-Ni alloy and pure Ni.Comparing with Pd/C,the prepared Ni-Pd/C nanoparticles exhibited better resolved voltammetric peaks between the hydrogen absorption and adsorption,and positively shifted current peaks for the reduction of Pd oxide.The prepared Ni-Pd alloys with Pd-enriched surface have significantly enhanced ORR activity and improved CH3OH tolerance as comparing with Pd/C catalysts.

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Complex Reduction Preparation Of Carbon Supported Pd Nanoparticle Catalyst And Its Electrocatalysis For Formic Acid Oxidation, Wei He, Yong-Yin Kang, Chong Du, Zhi-Qing Zou, Xiao-Gang Zhang, Hui Yang Nov 2009

Complex Reduction Preparation Of Carbon Supported Pd Nanoparticle Catalyst And Its Electrocatalysis For Formic Acid Oxidation, Wei He, Yong-Yin Kang, Chong Du, Zhi-Qing Zou, Xiao-Gang Zhang, Hui Yang

Journal of Electrochemistry

A simple procedure involved the complexing of PdCl2 with sodium citrate followed by ethylene glycol reduction has been employed for the preparation of carbon-supported Pd nanoparticles(Pd/C).The XRD and TEM characterizations indicate that Pd nanoparticles with a small particle size were well-dispersed on carbon support.The mean particle sizes of the Pd/C catalysts were found to be increased from 2.7 to 5.8 nm with heat-treatments at different temperature.The mass activity of the Pd/C catalyst for formic acid electrooxidation increased with the decrease in Pd particle size.However,the specific activity increased with Pd particle size.Furthermore,the Pd/C catalyst with a particle size of ca.3.6 …

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Electrocatalytic Performance Of Carbon Supported Ir Catalysts With Different Ir Loadings For Ammonia Oxidation, Yu-Zhi Jiang, Qing-Mei Kong, Tian-Hong Lu, Yi-Ming Zhou, Ya-Wen Tang Nov 2009

Electrocatalytic Performance Of Carbon Supported Ir Catalysts With Different Ir Loadings For Ammonia Oxidation, Yu-Zhi Jiang, Qing-Mei Kong, Tian-Hong Lu, Yi-Ming Zhou, Ya-Wen Tang

Journal of Electrochemistry

The electrocatalytic performance of the Ir/C catalyst as the anodic catalyst in the amperometric and electrochemical NH3 sensor was investigated.The experimental results illustrated that in the NaClO4 neutral electrolyte,the electrocatalytic performance of the Ir/C catalyst for the NH3 oxidation is related to the Ir loading in the Ir/C catalyst.Among the Ir/C catalysts with different Ir loading,the best electrocatalytic activity,stability and sensitivity were achieved by the Ir/C catalyst with 10% Ir loadings.In addition,the current densities of the NH3 oxidation at the Ir/C catalysts with the different Ir loadings were linearly proportional to the NH3 concentration.The Ir/C …

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Cyclic Voltammetric And In-Situ Ftir Spectroscopic Studies Of Adsorption And Reduction Of No On Electrode Of Pt Nanoparticles, Qian Cheng, Yan-Xia Jiang, Dong-Mei Zeng, Shi-Gang Sun Nov 2009

Cyclic Voltammetric And In-Situ Ftir Spectroscopic Studies Of Adsorption And Reduction Of No On Electrode Of Pt Nanoparticles, Qian Cheng, Yan-Xia Jiang, Dong-Mei Zeng, Shi-Gang Sun

Journal of Electrochemistry

Adsorption and reduction of NO on electrode of Pt nanoparticles in acid solutions were studied by means of cyclic voltammetry(CV) and in-situ FTIR spectroscopy.The results indicated that the reduction of NO is a complicated process including the adsorption of NO on electrode surface.Two types of surface-bonded NO were determined on Pt nanoparticles.The weakly adsorbed NO was reduced between 0.6 V and-0.05 V,which yielded nitrous oxide(N2O) and ammonium(NH4+) as products;while the strongly bonded NO was reduced at more negative potentials between-0.05V and-0.15V,producing only NH4+ species.

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Research Progress Of Synergistic Effect Of Metal Oxides On Pt-Based Catalysts, Hui-Ping Yuan, Xun Guo, Xin-Ping Qiu, Wen-Tao Zhu, Li-Quan Chen Nov 2009

Research Progress Of Synergistic Effect Of Metal Oxides On Pt-Based Catalysts, Hui-Ping Yuan, Xun Guo, Xin-Ping Qiu, Wen-Tao Zhu, Li-Quan Chen

Journal of Electrochemistry

In this paper,the work of Pt-based catalysts modified by metal oxides as the anode catalysts of direct methanol fuel cell(DMFC) is reviewed.The relationship between the structure and the composition of the catalysts and the reaction mechanism,exiting problems and developing direction are discussed.

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Platinum Modified With Hydrogen Molybdenum/Tungsten Bronze As Electrocatalysts For Direct Small Organic Molecule Fuel Cell, Wei-Shan Li, Li-Peng Tian, Jun-Hua Du, Hong-Liang Huang, Wei Li, Li-Xia Zhang, Hong-Yan Yang, Pan-Pan Guo, Zhi-Hui Zhou, Xing-De Xiang, Zhao Fu Nov 2009

Platinum Modified With Hydrogen Molybdenum/Tungsten Bronze As Electrocatalysts For Direct Small Organic Molecule Fuel Cell, Wei-Shan Li, Li-Peng Tian, Jun-Hua Du, Hong-Liang Huang, Wei Li, Li-Xia Zhang, Hong-Yan Yang, Pan-Pan Guo, Zhi-Hui Zhou, Xing-De Xiang, Zhao Fu

Journal of Electrochemistry

There are several problems that limit the application of direct small organic fuel cell,including the use of precious platinum and the activity loss of platinum due to the intermediates poisons from the oxidation of small organic molecules.These problems have attracted wide interest and many solutions have been proposed.We have developed a new method to reduce the platinum usage and improve its activity,based on the modification of platinum with hydrogen molybdenum/tungsten bronze(HxMo(W)O3) was reviewed.

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Preparation Of Pt Nanoflower/Zno Composites Arrays And Their Electrocatalysis For Methanol Oxidation, Li Gao, Yi-Feng E, Lou-Zhen Fan Nov 2009

Preparation Of Pt Nanoflower/Zno Composites Arrays And Their Electrocatalysis For Methanol Oxidation, Li Gao, Yi-Feng E, Lou-Zhen Fan

Journal of Electrochemistry

The Pt nanoflower/ZnO(PtNF/ZnO) nanorod composites arrays were electrochemically prepared by controlling the hydrophobicity and the hydrophilicity of ZnO nanorods arrays.The Pt nanoflowers grew on the tip of ZnO nanorods,which maintain the vertical array of Zno nanorods with a high degree of size uniformity and high surface area.Compared with Pt nanoparticle covered ZnO nanorod arrays,which were prepared by controlling the hydrophilicities of ZnO nanorods and Pt nanoparticles,the PtNF/ZnO displayed highest electrocatalytic activities for the oxidation of methanol.

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Enhanced Visible Light Photoelectrochemical Performances With Nitrogen Doped Tio2 Nanowire Arrays, Xiao-Jun Lv, Yue-Ming Li, Hao Zhang, Da Chen, Jennifer Hensel, Jin Z Zhang, Jing-Hong Li Nov 2009

Enhanced Visible Light Photoelectrochemical Performances With Nitrogen Doped Tio2 Nanowire Arrays, Xiao-Jun Lv, Yue-Ming Li, Hao Zhang, Da Chen, Jennifer Hensel, Jin Z Zhang, Jing-Hong Li

Journal of Electrochemistry

Self-organized anodic anatase TiO2 nanowire arrays doped with nitrogen have been successfully fabri-cated and their photoelectrochemical(PEC) properties have been characterized and found to be substantially im-proved compared to undoped nanowires or commercial P25 nanoparticles.Photocurrent measured with monochro-matic incident light showed that the incident photon-to-current efficiency(IPCE,%) values of nanowire arrayelectrodes with or without N-doping were obviously higher than that of commercial P25 nanoparticle electrodes,and nitrogen-doped TiO2 nanowire arrays(NTNA) had noticeable absorption in the visible region.The NTNAelectrodes showed the highest photocurrent density and power conversion efficiency under 100 mW/cm2 visiblelight illumination.A maximumolphotoconversion efficiency of 0.52% was achieved for the …

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Synthesis Of α-Mno2 Microspheres For The Application In Supercapacitor, Liang Wang, Gui-Chang Liu, Zhi-Cong Shi Nov 2009

Synthesis Of α-Mno2 Microspheres For The Application In Supercapacitor, Liang Wang, Gui-Chang Liu, Zhi-Cong Shi

Journal of Electrochemistry

The MnO2 microspheres were prepared through the oxidation of KMnO4 and MnCO3 microspheres precursor.The microstructure and supercapacitor properties of MnO2 were characterized by XRD,SEM and CV.The results show that MnO2 was in a poorly crystalline state with α-crystallographic form,the size of microspheres typically ranged from 0.5 to 2 μm.Loading 5 mg·cm-2 MnO2 microspheres had excellent capacitance behaviors in 2 mol·L-1(NH4)2SO4 solution.The specific capacitance was 135.6 F·g-1 with the scan rate at 2 mV·s-1,and 118.8 F·g-1 with the large scan rate at 100 …

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Enhanced [Ru(Bpy)3]2+-Mediated Oxidation Of Guanine Prompted By Dhp, Bao-Lian Zhang, Wei Hong, Bao-Yi Lu, Hong Li Nov 2009

Enhanced [Ru(Bpy)3]2+-Mediated Oxidation Of Guanine Prompted By Dhp, Bao-Lian Zhang, Wei Hong, Bao-Yi Lu, Hong Li

Journal of Electrochemistry

The effects of dihexadecyl phosphate(DHP) and multi-walled carbon nanotubes(MWNTs) on the oxidation of guanine mediated by[Ru(bpy)3]2+ on the ITO electrode have been investigated by cyclic voltammetry and differential pulse voltammetry.The results showed that [Ru(bpy)3]2+ can mediate the oxidation.In the range from 0.01 to 0.15 mmol·L-1,peak currents for guanine oxidation mediated by [Ru(bpy)3]2+ increased with the rise of DHP concentrations.On the contrary,cationic surfactant HTAC has the ability to weaken the mediated oxidation of guanine.In addition,the oxidative mechanism of guanine mediated by [Ru(bpy)3]2+ with the participation of DHP …

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Electrocatalytic Activities Of Au-Mmni(3.2)Al(0.2)Mn(0.6)Co(1.00) For Borohydride Oxidation, Gui-Ling Wang, Jin-Cheng Liu, Ke-Ning Sun, Dian-Xue Cao Nov 2009

Electrocatalytic Activities Of Au-Mmni(3.2)Al(0.2)Mn(0.6)Co(1.00) For Borohydride Oxidation, Gui-Ling Wang, Jin-Cheng Liu, Ke-Ning Sun, Dian-Xue Cao

Journal of Electrochemistry

In this work,the electrocatalytic activities of MmNi3.2Al0.2Mn0.6Co1.0, NaOH treated MmNi3.2Al0.2Mn0.6Co1.0 and Au-MmNi3.2Al0.2Mn0.6Co1.0 obtained after NaOH treatment(Mm: misch metal) for NaBH4 oxidation were reported. The electrodes were prepared by electrodeposition, their morphologies were analysized by SEM, their electrocatalytic properties were studied by the linear sweeping test. It was found that the oxidation current density of the Au-MmNi3.2Al0.2Mn0.6Co1.0 was 60 mA·cm-2, it was 3.5 times higher than that at the …

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Electrocatalysis Of Myoglobin-Chitosan-Au Colloid Film Modified Glass Carbon Electrode, Yu-Hua Qin, Jun Guo, Hui Xu, Li-Heng Zhou, Sheng-Tian Wang Nov 2009

Electrocatalysis Of Myoglobin-Chitosan-Au Colloid Film Modified Glass Carbon Electrode, Yu-Hua Qin, Jun Guo, Hui Xu, Li-Heng Zhou, Sheng-Tian Wang

Journal of Electrochemistry

The cyclic voltammgram of Mb/AAO/Au Colloid/GCE shows a pair of well-defined and nearly reversible peaks at about-0.20 V(vs.Ag/AgCl) in 0.1 mol/L NaAc-HAc buffer(pH = 5.4),being the characteristic peaks of the Mb heme Fe(Ⅲ) / Fe(Ⅱ)redox couples.The electron transfer between Mb and the electrode was greatly enhanced under present testing conditions.The effects of scan rate,pH and buffers concentration on the electrochemical behaviors of Mb were studied in detail.Position of the Soret absorbance band suggested that Mb in chitosan-colloidal gold hept its secondary structure similar to the native states.Oxygen was catalytically reduced by Mb in chitosan-colloidal gold films.

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Semi-Automatic Image Segmentation For Volumetric Visualization Of Pelvis Ct Scan-Images, Suprijanto Suprijanto, Farida I. Muchtadi, Irwan Setiawan Nov 2009

Semi-Automatic Image Segmentation For Volumetric Visualization Of Pelvis Ct Scan-Images, Suprijanto Suprijanto, Farida I. Muchtadi, Irwan Setiawan

Makara Journal of Technology

Semi-Automatic Image Segmentation for Volumetric Visualization of Pelvis CT Scan-Images. The current development of computerized tomography (CT) has enable us to obtain cross sectional image using multi slicing techniques in an order of few seconds. The obtained images represent several tissue structures on cross section slice being imaged. One challenge to help diagnosis using CT images is extracting an anatomic structure of interest using a method of image segmentation and volumetric visualization with the assistance of computers. In case of volumetric visualization of pelvis bones extracted from multi-slice CT images, whole images which are containing part of pelvis bone structures …

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Implementation Of Six Sigma Method To Maintain The Quality Of Construction Projects, Yusuf Latief, Retyaning Puji Utami Nov 2009

Implementation Of Six Sigma Method To Maintain The Quality Of Construction Projects, Yusuf Latief, Retyaning Puji Utami

Makara Journal of Technology

Implementation of Six Sigma Method to Maintain The Quality of Construction Projects. Six sigma (6-sigma) is a method that widely developed in the world, especially in manufacturing industry to decrease failures in achieving good quality in construction projects. The objective of this research is to explore the existing condition of quality management and the aplication of 6-sigma method in maintaining quality of construction projects. Structured interviews to experienced experts and people who were recommended by their companies were conducted. Non-parametric analysis using frequencies distribution procedures were used for analysis. The result shows that existing condition in quality management of construction …

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Mechanical Properties Of Ramie Fiber Reinforced Epoxy Lamina Composite For Socket Prosthesis, Tresna P. Soemardi, Widjajalaksmi Kusumaningsih, Agustinus Purna Irawan Nov 2009

Mechanical Properties Of Ramie Fiber Reinforced Epoxy Lamina Composite For Socket Prosthesis, Tresna P. Soemardi, Widjajalaksmi Kusumaningsih, Agustinus Purna Irawan

Makara Journal of Technology

Mechanical properties of ramie fiber reinforced epoxy lamina composite for socket prosthesis. This paper presents an investigation into the application of natural fiber composite especially ramie fiber reinforced epoxy lamina composite for socket prosthesis. The research focuses on the tensile and shear strength from ramie fiber reinforced epoxy lamina composite which will be applied as alternative material for socket prosthesis. The research based on American Society for Testing Material (ASTM) standard D 3039/D 3039M for tensile strength and ASTM D 4255/D 4255M-83 for shear strength. The ramie fiber applied is a fiber continue 100 % Ne14'S with Epoxy Resin Bakelite …

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Potency Of Thermoelectric Generator For Hybrid Vehicle, Nandy Putra, Raldi Artono Koestoer, Mohammad Adhitya, Ardian Roekettino, Bayu Trianto Nov 2009

Potency Of Thermoelectric Generator For Hybrid Vehicle, Nandy Putra, Raldi Artono Koestoer, Mohammad Adhitya, Ardian Roekettino, Bayu Trianto

Makara Journal of Technology

Potency of Thermoelectric Generator for Hybrid Vehicle. Thermoelectric Generator (TEG) has been known as electricity generation for many years. If the temperature difference occurred between two difference semi conductor materials, the current will flow in the material and produced difference voltage. This principle is known as Seebeck effect that is the opposite of Peltier effect Thermoelectric Cooling (TEC). This research was conducted to test the potential of electric source from twelve peltier modules. Then, these thermoelectric generators were applied in hybrid car by using waste heat from the combustion engine. The experiment has been conducted with variations of peltier module …

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Effects Of Ph On Calcium Carbonate Precipitation Under Magnetic Field, Nelson Saksono, Yuliusman Yuliusman, Setijo Bismo, Roekmijati W. Soemantojo, Azwar Manaf Nov 2009

Effects Of Ph On Calcium Carbonate Precipitation Under Magnetic Field, Nelson Saksono, Yuliusman Yuliusman, Setijo Bismo, Roekmijati W. Soemantojo, Azwar Manaf

Makara Journal of Technology

Magnetic field effect on CaCO3 precipitation is the key parameter in evaluating the effectiveness of Anti-scale Magnetic Treatment (AMT). The purpose of this study was to investigate magnetic fields influence on CaCO3 precipitation in high and low super-saturated CaCO3 solution by varied pH CaCO3 solution using circulation flow fluid system. The observation results in the high super saturated solution (pH 8.5) showed the increase of precipited CaCO3 in magnetized solutions compared to those in non-magnetic solution during circulation process. In the low super-saturated CaCO3 solution (pH 6.4) it was found that magnetic treatment increased CaCO3 precipitation after circulation process. In …

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Performance Of Hollow Fiber Membrane Gas-Liquid Contactors To Absorb Co2 Using Diethanolamine (Dea) As A Solvent, Sutrasno Kartohardjono, Pan Ade Nata, Eko Prasetio, Yuliusman Yuliusman Nov 2009

Performance Of Hollow Fiber Membrane Gas-Liquid Contactors To Absorb Co2 Using Diethanolamine (Dea) As A Solvent, Sutrasno Kartohardjono, Pan Ade Nata, Eko Prasetio, Yuliusman Yuliusman

Makara Journal of Technology

This study uses DEA solution to absorb CO2 from the gas flow through the hollow fiber membrane contactors. This study aims to evaluate the performance of hollow fiber membrane contactors to absorb CO2 gas using DEA solution as solvent through mass transfer and hydrodynamics studies. The use of DEA solution is to reduce the mass transfer resistance in the liquid phase, and on the other side, the large contact area of the membrane surface can cover the disadvantage of membrane contactors; additional mass transfer resistance in the membrane phase. During experiments, CO2 feed flows through the fiber lumens, while the …

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Intermetallic Cu3sn Phase Layer On Electrode’S Tip Of Galvanized Resistance Spot Welding, Muhammad Anis, Aulia Irsyadi, Deni Ferdian Nov 2009

Intermetallic Cu3sn Phase Layer On Electrode’S Tip Of Galvanized Resistance Spot Welding, Muhammad Anis, Aulia Irsyadi, Deni Ferdian

Makara Journal of Technology

Intermetallic Cu3Sn Phase Layer on Electrode’s Tip of Galvanized Resistance Spot Welding. A resistance spot welding method is commonly used in automotive industries application. In a resistance spot welding method, the copper electrode has a significant role as an electric current carrier for joining thin metal sheet. This research was focused on studying the effect of tin layer at the electrode tip for joining galvanized steel sheet. The main variable of this research is in the thickness of the intermetallic Cu3Sn layer. The result showed that the introduction of tin layer less than 1 μm in thickness on the electrode …

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Simple Ml Detector For Multiple Antennas Communication System, Ahmad Taqwa, Soegijardjo Soegijoko, Sugihartono Sugihartono, Suhartono Tjondronegoro Nov 2009

Simple Ml Detector For Multiple Antennas Communication System, Ahmad Taqwa, Soegijardjo Soegijoko, Sugihartono Sugihartono, Suhartono Tjondronegoro

Makara Journal of Technology

Simple ML Detector for Multiple Antennas Communication System. In order to support providing broadband wireless communication services against limited and expensive frequency bandwidth, we have to develop a bandwidth efficient system. Therefore, in this paper we propose a closed-loop MIMO (Multiple-Input-Multiple-Output) system using ML (Maximum Likelihood) detector to optimize capacity and to increase system performance. What is especially exciting about the benefits offered by MIMO is that a high capacity and performance can be attained without additional frequency-spectral resource. The grand scenario of this concept is the attained advantages of transformation matrices having capability to allocate transmitted signals power suit …

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Ole Miss Engineer 2009 Oct 2009

Ole Miss Engineer 2009

Ole Miss Engineer

No abstract provided.

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Bs News Oct 2009

Bs News

Building Services Engineering

No abstract provided.

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A Modified Newton Method For Solving Non-Linear Algebraic Equations, Satya N. Atluri, Chein-Shan Liu, Chung-Lun Kuo Sep 2009

A Modified Newton Method For Solving Non-Linear Algebraic Equations, Satya N. Atluri, Chein-Shan Liu, Chung-Lun Kuo

Journal of Marine Science and Technology–Taiwan

The Newton algorithm based on the “continuation” method may be written as being governed by the equation xj(t) + Bij-1 Fi(xj) = 0, where Fi(xj) = 0, i, j = 1, …n are nonlinear algebraic equations (NAEs) to be solved, and Bij = ∂Fi /∂xj is the corresponding Jacobian matrix. It is known that the Newton's algorithm is quadratically convergent; however, it has some drawbacks, such as being sensitive to the initial guess of solution, and being expensive in the computation of the inverse of Bij at each iterative step. How to preserve the convergence speed, and to remove the …

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Simulation Of Cnt Composites Using Fast Multipole Bem, Zhen-Han Yao, Jun-Dong Xu, Hai-Tao Wang, Xiao-Ping Zheng Sep 2009

Simulation Of Cnt Composites Using Fast Multipole Bem, Zhen-Han Yao, Jun-Dong Xu, Hai-Tao Wang, Xiao-Ping Zheng

Journal of Marine Science and Technology–Taiwan

This paper addresses some applications of the fast multipole boundary element method on the simulation of CNT composites, including the simulation of elastic, thermal and electric properties. The carbon nanotubes are treated as effective elastic fibers for the simulation of elastic property, and treated as straight fibers with high thermal conductivity and high electric conductivity for the simulation of thermal and electric properties respectively. The numerical examples are compared with other numerical results and experimental data published in literature. To reduce the difference between numerical and experimental value of effective elastic modulus, two approaches with nonideal interfacial condition or additional …

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Novel Methods For Solving Severely Ill-Posed Linear Equations System, Chein-Shan Liu, Chih-Wen Chang Sep 2009

Novel Methods For Solving Severely Ill-Posed Linear Equations System, Chein-Shan Liu, Chih-Wen Chang

Journal of Marine Science and Technology–Taiwan

We treat an ill-posed system of linear equations by transforming it into a linear system of stiff ordinary differential equations (SODEs), adding a differential term on the left-hand side. In order to overcome the difficulty of numerical instability when integrating the SODEs, Liu [20] has combined nonstandard finite difference method and group-preserving scheme, namely the nonstandard group-preserving scheme (NGPS), to obtain an unconditional stable numerical method for SODEs. This paper applies the NGPS to the SODEs resulting from the ill-posed linear equations, and proves that the new algorithms are unconditional stable. To strengthen accuracy, an L-curve is used to select …

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