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Articles 61 - 79 of 79

Full-Text Articles in Engineering

Synthesis Dibenzyl Terephthalate Through Depolimerization Of Poly (Ethylene Terephthalate) As Alternative Of Waste Plastics Recycling, Suwardi Suwardi, Crys Fajar Partana, Agus Salim, Dyah Anitasari Apr 2005

Synthesis Dibenzyl Terephthalate Through Depolimerization Of Poly (Ethylene Terephthalate) As Alternative Of Waste Plastics Recycling, Suwardi Suwardi, Crys Fajar Partana, Agus Salim, Dyah Anitasari

Makara Journal of Technology

Synthesis Dibenzyl Terephthalate Through Depolimerization of Poly(ethylene terephthalate) as Alternative of Waste Plastics Recycling. Synthesis dibenzyl terephathalate were done through PET degradation by refluxing in benzyl alcohol at 145oC temperature for 20, 24, and 28 hours in the presence of zinc acetate catalyst. The result of degradation was purified by recristalization in methanol and then melting point (mp), FTIR, 1H NMR spectra, and TLC spot were determined. The melting point of product degradation for 28 hours was 98-99 oC. Based FTIR spectra known that compunds of product degradation have OH, C=O, C-O, CH, monosubstituted benzene, disubstituted benzene groups, while on …


3d Modelling With Linear Approaches Using Geometric Primitives, Mochammad Zuliansyah Apr 2005

3d Modelling With Linear Approaches Using Geometric Primitives, Mochammad Zuliansyah

Makara Journal of Technology

In this paper, we study linear approaches for 3D model acquisition from non-calibrated images. First, the intrinsic and extrinsic camera calibration is taken into consideration. In particular, we study the use of a specific calibration primitive: the parallelepiped. Parallelepipeds are frequently present in man-made environments and naturally encode the affine structure of the scene. Any information about their euclidean structure (angles or ratios of edge lengths), possibly combined with information about camera parameters is useful to obtain the euclidean reconstruction. We propose an elegant formalism to incorporate such information, in which camera parameters are dual to parallelepiped parameters, i.e. any …


Dipole Magnetization Effect To Kerosene Characteristics, Mochamad Chalid, Nelson Saksono, Adiwar Adiwar, Nono Darsono Apr 2005

Dipole Magnetization Effect To Kerosene Characteristics, Mochamad Chalid, Nelson Saksono, Adiwar Adiwar, Nono Darsono

Makara Journal of Technology

Dipole Magnetization Effect to Kerosene Characteristics. Investigation of kerosene characteristics has been done by ex-situ dipole magnetization. The results show that magnetization technique can be able to influence kerosene characteristics. Polarity and viscosity of the kerosene are observed by measuring refractive index and viscosity. An hour of 4330 Gauss flux magnetic will increase refractive index from 1.447 to 1.449 and decrease the viscosity from 1.278 to 1.256. Those changing support de-clustering occurrence and polarity increment of kerosene molecule. Gas chromatography and infrared result show that those changing do not alter kerosene structure and composition.


Time Domain Characterization Of 1-2 Ghz Circular-Ended Bowtie Antenna Using Normalizad Impulse Response, Joko Suryana, Andriyan B. Suksmono, Tati R. Mengko Apr 2005

Time Domain Characterization Of 1-2 Ghz Circular-Ended Bowtie Antenna Using Normalizad Impulse Response, Joko Suryana, Andriyan B. Suksmono, Tati R. Mengko

Makara Journal of Technology

Time Domain Characterization of 1-2 GHz Circular-ended Bowtie Antenna Using Normalizad Impulse Response. Frequency domain analysis is a powerful and compact tool for characterizing the antenna parameters such as gain, radiation pattern and the impedance as a function of frequency. However, if time or space is a major concern, such as in the GPR appication, the time domain analysis would be a very important tool due to their unique capability for determining the echo delay and range profile of target image. In this paper, we will describe the classical theory of system characterization in time domain, and then also propose …


Study Of 2d And 3d Optical Beam Induced Voltage Imaging Using Photoresistor Sensor, Warsito Warsito, Sri Wahyu Suciyati, Susi Harnani, Akhmad Dzakwan Apr 2005

Study Of 2d And 3d Optical Beam Induced Voltage Imaging Using Photoresistor Sensor, Warsito Warsito, Sri Wahyu Suciyati, Susi Harnani, Akhmad Dzakwan

Makara Journal of Technology

Study of 2D and 3D Optical Beam Induced Voltage Imaging Using Photoresistor Sensor. This article shows a method to study OBIV (optical beam induced voltage) imagerie system, that usually employ a laser scanning microscopy system. The OBIV imagerie system developed use a photoresistor sensor as a sample and simultaneously it can be used for analyzing its inhomogeneity response. Resolution of the system is still low, about 350μm due to high value of incident light diameter. The results inform that photoresistor sensors gave an optimum response if the incident light hits the center of sensible zone.


Application Of Carbon Paste Electrode On The Electrogenerative-Leaching Process Of Sulfide Minerals, Shao-Fen Wang Feb 2005

Application Of Carbon Paste Electrode On The Electrogenerative-Leaching Process Of Sulfide Minerals, Shao-Fen Wang

Journal of Electrochemistry

The cyclic voltammetry curves of sulfide mineral electrodes or corresponding carbon paste electrodes in NaCl electrolytes have been obtained in this study. The experimental results indicate that acetylene black (revealed) the electro-catalytic propertyin the electrogenerative-leaching process of sulfide minerals. The output currentand potential of carbon paste electrodes were increased to some degrees while the activation energies were lower.


Anodic Polarization Behaviors Of Carbon Steel In Bicarbonate Solution, Jing-Mao Zhao, Yu Zuo Feb 2005

Anodic Polarization Behaviors Of Carbon Steel In Bicarbonate Solution, Jing-Mao Zhao, Yu Zuo

Journal of Electrochemistry

The anodic polarization curves of mild steel were measured in sodium bicarbonate solution of various concentrations, and the surface products were analyzed by XPS. Two anodic current peaks and two passive zones are observed in all the curves. When HCO_3~- ions concentration is below 0.1mol/L, the two peaks are so close that the first passive zone is difficult to be observed. When HCO_3~- ions concentration is above 0.1 mol/L, the first peak appears clear, while the second becomes smaller. The XPS results indicate that the out layer of film formed at a higher potential is mainly composed of Fe_2O_(3,) and …


Research On Phenol Wastewater Treatment By Electrochemical Oxidation, Tian-Cheng Li, Shen-Lin Zhu Feb 2005

Research On Phenol Wastewater Treatment By Electrochemical Oxidation, Tian-Cheng Li, Shen-Lin Zhu

Journal of Electrochemistry

Electrochemical oxidation is an effective technology for the phenol wastewater treatment, and the anode properties are important to the electrochemical oxidationefficiency. The over-potentials of oxygen evolution have been measured for thestainless steel, feasible graphite and SnO_2/Ti anode respectively. Moreover, the synthetic phenol wastewater was treated by the electrochemical oxidation with the stainless steel or feasible graphite anodes. The experimental results showed that the order of the over-potential is SnO_2/Ti > graphite > stainless steel; meanwhile, the COD values of purified water were approaching to or less than 100 mg·L~(-1), and the phenol concentrations in the purified water were below 0.5 mg·L~(-1).


Influence Of Rare Earth Oxide On The Performance Of Secondary Zinc Electrodes, Xian-Ling Meng, Hua-Bin Yang, Jun-Hong Wang, Zuo-Xiang Zhou Feb 2005

Influence Of Rare Earth Oxide On The Performance Of Secondary Zinc Electrodes, Xian-Ling Meng, Hua-Bin Yang, Jun-Hong Wang, Zuo-Xiang Zhou

Journal of Electrochemistry

Influence of La(OH)_(3 )or Ce(OH)_3in secondary zinc electrode was investigated by the cyclic voltammetry, potentiodynamic polarizationand potentiostatic polarization tests and influence of La_2O_3or CeO_2in the charge/discharge performance of Zn/Ni battery was studied by galvanostatic charge/discharge experiment. The results showed that the film of rare earth hydroxide prevented the zincate species from transferring toward solution, enhanced hydrogen overpotential and decreased thecorrosion current density (i_(corr)), and therefore inhibited zinc corrosion. The potentiostatic polarization results at100mV overpotential showed thatLa(OH)_3or Ce(OH)_3coated on the zinc electrode effectively suppressed the zinc dendrite growth. The La_2O_(3 )or CeO_2addition to the calcium zincate electrode improved the cycle performance …


Calcium Zincate Prepared By Ball Mill Method, Sheng-Xian Li, Shuan-Bao Tian, Shao-Shan Zhu Feb 2005

Calcium Zincate Prepared By Ball Mill Method, Sheng-Xian Li, Shuan-Bao Tian, Shao-Shan Zhu

Journal of Electrochemistry

Calcium zincate was prepared by ball milling method and the factors that influence its synthesis were investigated. The composition of the compound was Ca(OH)_2·2Zn(OH)_22H_2O, which was verified by XRD and TG-DTA methods. The results of powder microelectrode and in simulated batteries showed that the material had excellent cyclic performance.


The Fabrication And Electrochemical Studies On Carbon Nanotube Array Electrodes, Quan-Yong Gao, Jing Zhang, Yangyong Yangyong Feb 2005

The Fabrication And Electrochemical Studies On Carbon Nanotube Array Electrodes, Quan-Yong Gao, Jing Zhang, Yangyong Yangyong

Journal of Electrochemistry

An improved technique for fabrication of carbon nanotube array electrodes has been proposed in this work. Firstly, carbon nanotubes (CNs) array electrodes were prepared by combsination of Chemical Vapor Decomposition (CVD) method and sputtering techniques in anodized aluminum oxide (AAO) membrane. The CNs/AAO was immersed into HF solution to remove the barrier layer. Controlling the immersing time, the CNs array electrodes with different length contacted with electrolyte can be prepared. The morphology of CNs array electrodes was observed by SEM. The electrochemical properties of CNs array electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Cyclic voltammetric curves of …


Preparation And Characterization Of Lini_(0.85)Co_(0.10)(Timg)_(0.025)O_2 As Cathode Materials For Lithium-Ion Batteries, Xian-Jun Zhu, Hong-Hao Chen, Hui Zhan, Dai-Ling Yang, Yun-Hong Zhou Feb 2005

Preparation And Characterization Of Lini_(0.85)Co_(0.10)(Timg)_(0.025)O_2 As Cathode Materials For Lithium-Ion Batteries, Xian-Jun Zhu, Hong-Hao Chen, Hui Zhan, Dai-Ling Yang, Yun-Hong Zhou

Journal of Electrochemistry

Cathode material of LiNi_(0.85)Co_(0.10)(TiMg)_(0.025)O_2 were prepared by solid state reaction at 725℃ for 24 h from LiOH·H_2O, Ni_2O_3, Co_2O_3, TiO_2 and Mg(OH)_2 under flowing oxygen, and were characterized by TG-DTA, XRD, SEM and electrochemical tests. Effort to simultaneously doped LiNiO_2 with Co-Ti-Mg has been tried to improve the cathode performance. The results show that co-doping definitely has a large beneficial effect in increasing the capacity (182.7mAh/g of the first discharge capacity for LiNi_(0.85)Co_(0.10)(TiMg)_(0.025)O_2) and cycling behavior (175.5 mAh/g after 10 cycles). This cathode materials can be applied for lithium-ion batteries.


Corrosion Behavior Of Mg_(2-X)La_Xni And Mg_(2-X)Ce_Xni Hydrogen Storage Alloy, Hai-Chang Zhang, Hua-Bin Yang, Jun-Hong Wang, Zuo-Xiang Zhou Feb 2005

Corrosion Behavior Of Mg_(2-X)La_Xni And Mg_(2-X)Ce_Xni Hydrogen Storage Alloy, Hai-Chang Zhang, Hua-Bin Yang, Jun-Hong Wang, Zuo-Xiang Zhou

Journal of Electrochemistry

The corrosion behavior of Mg-base hydrogen storage alloys has been investigated by potentiodynamic polarization and EIS. The results showed that the corrosion current density (i_(corr) ) and the electrochemical polarized resistance of Mg_(2-x)Ce_xNi alloys decreased with x increase, while i_(corr) of Mg_(2-x)La_xNi alloys increased and the electrochemical polarized resistance of Mg_(2-x)La_xNi alloys increased first, then decreased with x increase. SEM results showed that the surface of Mg_(1.85)Ce_(0.15)Ni alloy was relatively even while the surface of Mg_(2-x)La_xNi alloy had remarkedly cracks. The different behavior between Ce and La may be relevant to the structure of Ce, La oxides.


Electrochemical Performance Of Gel Polymer Electrolyte Prepared By Thermal Initiating Polymerization Of Acrylates, Jin-Dan Piao, Li-Xia Yuan, Xin-Ping Ai, Han-Xi Yang, Yu-Liang Cao Feb 2005

Electrochemical Performance Of Gel Polymer Electrolyte Prepared By Thermal Initiating Polymerization Of Acrylates, Jin-Dan Piao, Li-Xia Yuan, Xin-Ping Ai, Han-Xi Yang, Yu-Liang Cao

Journal of Electrochemistry

A gel polymer electrolyte was prepared by thermal initiating polymerization of the acrylates in the EC/EMC/DMC electrolyte solution at 100℃. The LiCoO_2/MCMB polymer cells were assembled and their electrochemical properties were evaluated at various charge-discharge rate and temperatures. The ionic conductivity of the polymer electrolyte containing 85wt.% liquid electrolyte is around 3.2×10~(-3)S·cm~(-1) at 20℃ and 5.6×10~(-4)S·cm~(-1)at -30℃ respectively. The gel polymer electrolyte has good electrochemical stability up to 4.5V versus Li/Li~(+).The first charge-discharge efficiency of the polymer cell at 0.2C rate is almost 92.1%. The discharge capacity of the cell at 1.0C rate is 95% of the capacity at the …


Electrochemical Properties Of Polymeric Gel Electrolyte With Gbl/Ec As Plasticizers, Yu-Wen Liu, Yong Zhang, Xiao-Long Li, Qi-Ping Gu, Cui-Fen Zhang, Yu-Dong Huang Feb 2005

Electrochemical Properties Of Polymeric Gel Electrolyte With Gbl/Ec As Plasticizers, Yu-Wen Liu, Yong Zhang, Xiao-Long Li, Qi-Ping Gu, Cui-Fen Zhang, Yu-Dong Huang

Journal of Electrochemistry

Polymeric gel electrolytes (GPE) based on PMMA and PVDF-HFP were prepared using the binary mixtures of γ-butyrolactone (GBL) and ethylene carbonate (EC) as plasticizers. The ionic transport properties and electrochemical stability were studied. The room temperature conductivity reached 1.2 mS·cm~(-1), electrochemical stability window exceeded 4.5V. The interfacial stability between GPE and lithium electrode was also investigated. The lithium metal polymer battery (LMPB) prepared with the GPE showed better charge and discharge life cycle when the the lithium metal electrode was treated with 1,4-dioxane.


Corrosion Resistance For Tio_2 Thin Films Coated 316l Stainless Steel In The Nacl Solution, Guang-Xia Shen, Yi-Cong Chen, Chang-Jian Lin Feb 2005

Corrosion Resistance For Tio_2 Thin Films Coated 316l Stainless Steel In The Nacl Solution, Guang-Xia Shen, Yi-Cong Chen, Chang-Jian Lin

Journal of Electrochemistry

The nano-TiO_2 thin films have been deposited on the 316L stainless steel by sol-gel and the dip- coating methods. Hydrothermal post-treatment leads to crack-free coatings. Meanwhile, the surface structure and properties are optimized. Surface morphology, structure and properties are characterized by XRD, and SEM technologies. The results have shown that the surface of coatings is porous, uniform and orderly, the particle diameters are in the range of 15~18nm and the pores are about 4~8nm and TiO_2 is anatase. The results of electrochemical measurements show that in the NaCl solution with pH ≥ 2 and concentration below 1mol/L, the nano-TiO_2 coatings …


A Study Of Metal Borides As High Capacity Anode Materials For Aqueous Primary Batteries, Ya-Dong Wang, Xin-Ping Ai, Han-Xi Yang Feb 2005

A Study Of Metal Borides As High Capacity Anode Materials For Aqueous Primary Batteries, Ya-Dong Wang, Xin-Ping Ai, Han-Xi Yang

Journal of Electrochemistry

The transition metal borides VB_2 and TiB_2 were tested as high capacity anode materials and their electrochemical behaviors were studied by cyclic voltammetry and discharge measurements. The experimental results indicated that transition metal borides VB_2 and TiB_2 electrodes can deliver exceptionally high discharge capacity of over 3100 mAH/g and 1 600 mAH/g respectively, corresponding to 11- and 6-electron oxidation reaction, although their parent elements V, Ti and boron, are almost completely electrochemically inert. The different electrochemical activitis were probably due to the electrochemical activation of boron, which clamp the potential to passivation for Ti and activity for V.


Preparation Of Poly ( Bromophenol Blue ) Modified Glassy Carbon Electrode And Its Electrocatalytic Activity, Wei Chen, Hong-Bin Luo, Xin-Hua Lin Feb 2005

Preparation Of Poly ( Bromophenol Blue ) Modified Glassy Carbon Electrode And Its Electrocatalytic Activity, Wei Chen, Hong-Bin Luo, Xin-Hua Lin

Journal of Electrochemistry

A film of poly ( bromophenol blue ) was formed on a glassy carbon electrode by using cyclic voltammetry. A stable film could be obtained with a potential range from -1.0V to +1.8V(vs.Ag/AgCl). The experimental results showed that the poly ( bromophenol blue ) modified glassy carbon electrode could catalyse the oxidation of ascorbic acid. It decreased the oxidation potential by about 270mV but increased the peak current. Meanwhile, this electrode showed a good linear current response for the ascorbic acid range from 2.5 to 250 (g/mL.)


Fabrication And Studies Of A Novel Ag/Agcl Reference Electrode In High Temperature Molten Chloride Salts, Pei Gao, Xian-Bo Jin, Di-Hua Wang, Xiao-Hong Hu, Zheng Chen Feb 2005

Fabrication And Studies Of A Novel Ag/Agcl Reference Electrode In High Temperature Molten Chloride Salts, Pei Gao, Xian-Bo Jin, Di-Hua Wang, Xiao-Hong Hu, Zheng Chen

Journal of Electrochemistry

A new method for the easy fabrication of a stable and long life silver/silver chloride reference electrode in molten chloride salts is described in this paper. The method is based on the fact that simply placing the silica glass in molten NaCl or its vapour in the presence of oxygen resulted in satisfactory conductivity for sodium ion and possibly calcium ion in the material.The performance of such made electrode has been investigated in a few typical chloride systems at temperatures ranging from 400 to 900℃. Due to the wholly sealed construction, the reference electrode is stable, temperature-reversible, contamination free to …