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Articles 1561 - 1590 of 1824

Full-Text Articles in Chemical Engineering

Adoption Of Variable Rate Technology, Isti Surjandari, Marvin T. Batte Dec 2003

Adoption Of Variable Rate Technology, Isti Surjandari, Marvin T. Batte

Makara Journal of Technology

Site Specific Management (SSM), which also variously referred to as Variable Rate Technology (VRT), is an emerging technology that enables producers to make more precise input application decisions based on soil and field characteristics. This study analyzes factors influencing the adoption of VRT for fertilizer application for cash grain production in Ohio. Results show that producer and field characteristics might influence the adoption decision on various SSM components differently. It also provides insight as to the sequence of adoption of SSM component technologies and how this sequence might differ for producers of differing characteristics.

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Study On Electrochromic Effect Of Polyaniline Film, Lienda Handojo, Junus Simangunsong Dec 2003

Study On Electrochromic Effect Of Polyaniline Film, Lienda Handojo, Junus Simangunsong

Makara Journal of Technology

Study on Electrochromic Effect of Polyaniline Film. The light transmission factor of an electrochromic film changes reversibly with the application of an electrical voltage. Thereby the transparent film becomes reversibly opaque so that it may be used to control light transmission. In this paper the results of a study on polyaniline film as an electrochromic active material is reported. Polyaniline looks yellow transparent in the reduced state and turns to green-blue at its oxidized state. The electrochromic device considered in this paper was fabricated in planar configuration of ITO glass − polyaniline film − electrolyte − ITO glass which involved …

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An Economic Analysis Of Variable Rate Technology, Isti Surjandari, Marvin T. Batte, Mario J. Miranda Dec 2003

An Economic Analysis Of Variable Rate Technology, Isti Surjandari, Marvin T. Batte, Mario J. Miranda

Makara Journal of Technology

Variable Rate Technology (VRT) offers an opportunity to improve production efficiency by allowing input applications to fluctuate in response to spatial variations in soil characteristics and nutrient levels. Society may also benefit from reduced negative externalities, such as surface and groundwater contamination, from input applications. Using a dynamic spatial model, this study examines how the interaction among variability, spatial autocorrelation, and mean level of soil fertility affects optimal sampling density and the economic gains from VRT. VRT was found to be profitable under selected conditions, and the optimal grid size will vary with these conditions. In the case where variability …

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Application Of Tabu Search Algorithm In Job Shop Scheduling, Betrianis Betrianis, Putu Teguh Aryawan Dec 2003

Application Of Tabu Search Algorithm In Job Shop Scheduling, Betrianis Betrianis, Putu Teguh Aryawan

Makara Journal of Technology

Application of Tabu Search Algorithm in Job Shop Scheduling. Tabu Search is one of local search methods which is used to solve the combinatorial optimization problem. This method aimed is to make the searching process of the best solution in a complex combinatorial optimization problem(np hard), ex : job shop scheduling problem, became more effective, in a less computational time but with no guarantee to optimum solution.In this paper, tabu search is used to solve the job shop scheduling problem consists of 3 (three) cases, which is ordering package of September, October and November with objective of minimizing makespan (Cmax). …

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Role Of K3-Xhxpw12o40 As A Catalyst In Selective Catalysis Of Methylamine Synthesis From Ammonia And Methanol, Mohammad Nasikin Dec 2003

Role Of K3-Xhxpw12o40 As A Catalyst In Selective Catalysis Of Methylamine Synthesis From Ammonia And Methanol, Mohammad Nasikin

Makara Journal of Technology

Role of K3-xHxPW12O40 as a Catalyst in Selective Catalysis of Methylamine Synthesis from Ammonia and Methanol. Synthesize of methylamine from methanol and ammonia was studied in this research work using a partially potassium heteropoly salt (K3-xHxPW12O40 abbreviated as KPW) as a catalyst. KPW was prepared from heteropoly salt and potassium carbonate by using ion exchange method. The reaction was conducted at 600 ~ 800K and at the atmospheric pressure. Reactor used was a continue flow reactor with W/F=0,1~0,9g-kat.mnt./cc.Concentration of reactants and products were analyzed by gas chromathography while catalyst structure was observed by XRD (X-ray diffraction). Isothermal adsorption method was …

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Identification Of The First Limiting Amino Acid In Cooked Polished White Rice Fed To Weanling Holtzman Rats, Mellova Masrizal, J. B. Lamb Dec 2003

Identification Of The First Limiting Amino Acid In Cooked Polished White Rice Fed To Weanling Holtzman Rats, Mellova Masrizal, J. B. Lamb

Makara Journal of Technology

Forty-eight male weanling rats (91 g) were utilized to study the nutritional adequacy of cooked polished white rice. Rats were individually housed, and allowed ad libitum access to one of six treatment diets. Treatment diets were 1) polished white rice plus 10% casein and 0.18% methionine, CAS, 2) polished white rice, WHR, 3) polished white rice plus 0.45% lysine, LYS, 4) polished white rice plus0.40% methionine, MET, 5) polished white rice plus 0.30% threonine, THR, 6) polished white rice plus 0.45% lysine, 0.40% methionine, and 0.40% threonine, COM. Rice was cooked prior diet formulation using a 3 to 1 ratio …

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Preparation And Characterization Of Y-Type Carbon Nanotubes By Using Anodized Alumina Oxide (Aao) Template, Jing Zhang, Quan-Yong Gao, Yong Yang Nov 2003

Preparation And Characterization Of Y-Type Carbon Nanotubes By Using Anodized Alumina Oxide (Aao) Template, Jing Zhang, Quan-Yong Gao, Yong Yang

Journal of Electrochemistry

In this work, potential-modulation method was used in two-step anodization process to make an AAO template with Y-type nanochannels. Then Y-type carbon nanotubes with controlled length and branch angle were prepared in the template based on chemical vapor decomposion (CVD) method with Co particles as catalyst and C2H2 as carbon source. The Y-type nanotube branches exhibit the angle distribution ranging from 20° to 120°. The results demonstrated that the oxidation potential should be responsible for the angles and length of the branches. Short pulse and high oxidation potential will result in the short and dense nanotube branches.

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Application Of Hydrogen-Storage Alloy Electrode In Electrochemical Reduction Of Glucose, Hui Chen, You-Gen Tang, Zheng Tang Nov 2003

Application Of Hydrogen-Storage Alloy Electrode In Electrochemical Reduction Of Glucose, Hui Chen, You-Gen Tang, Zheng Tang

Journal of Electrochemistry

Electrolysis of glucose was performed at constant potential using hydrogen-storage alloy as catalytic reduction electrode. It was found that the superficial treatment and activation of hydrogen-storage alloy powder had obvious effects on improving the current efficiency of sorbitol. Under the optimums, current efficiency of sorbitol by electrolyzing glucose was over 94%. The yield of sorbitol was over 80%, the lifespan of electrode was tested and analyzed, the ways of regeneration were discussed.

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Study On Degradation Of Phenol By Electrochemical Oxidation, Yue-Li Liu, Hong-Hua Ge Nov 2003

Study On Degradation Of Phenol By Electrochemical Oxidation, Yue-Li Liu, Hong-Hua Ge

Journal of Electrochemistry

Electrochemical oxidation of phenol was carried out by the Dimensionally Stable Anodes (DSA) electrode, which has been discarded as waste by alkali chloride factory. The result indicates that a good phenol removal can be obtained under certain phenol concentration by the DSA electrode. The key factor in effecting phenol removal of electrochemical oxidation is applied current density, the following factors are pH, electrolyte concentration and phenol concentration. After experiments, the optimal test conditions are 30 mA/cm2, pH 10, electrolyte concentration 10 mg/L, phenol concentration 10 mg/L.67% CODcr removal and 90% absorbance removal are gained by electrochemical oxidation for …

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Optimizing Catalyst Layer Composition Of Pemfc By Orthogonal Method, Ming-Hua Wang, Xin-Jian Zhu, Guang-Yi Cao, Sheng Sui, Qing-Chun Yu, Ming-Ruo Hu, Zheng-Yu Fan Nov 2003

Optimizing Catalyst Layer Composition Of Pemfc By Orthogonal Method, Ming-Hua Wang, Xin-Jian Zhu, Guang-Yi Cao, Sheng Sui, Qing-Chun Yu, Ming-Ruo Hu, Zheng-Yu Fan

Journal of Electrochemistry

The optimal composition of catalyst layer in a PEMFC electrode was studied through orthogonal method. It was showed that the performance of hydrophilic electrodes, in which there is no PTFE in the catalyst layer, were more favorable than that of hydrophobic electrodes. According to this condition, the power density of PEMFC attained 0.37 w·cm-2 when the Nafion loading was 1.4 mg·cm-2, and the Pt loading was 0.4 mg·cm-2 in the catalyst layer, using H2 as fuel and air as oxidant both at atmospheric pressure. Additionally, the results showed that increasing Pt loading in Pt/C catalyst …

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The Study On Carbon Nanotube-Loaded Pt Catalysts For Proton Exchange Membrane Fuel Cells, Hong Zhu, Feng-Juan Ge, Xiao-Hong Kang, Yu-Guo Yang, Yun-Hua Xu Nov 2003

The Study On Carbon Nanotube-Loaded Pt Catalysts For Proton Exchange Membrane Fuel Cells, Hong Zhu, Feng-Juan Ge, Xiao-Hong Kang, Yu-Guo Yang, Yun-Hua Xu

Journal of Electrochemistry

Carbon nanotube-supported-platinum (Pt/CNTs) and carbon-supported-platinum (Pt/C) catalysts were synthesized by in-situ chemical reduction. They were analyzed using TEM and XRD, then made into electrodes to be part of assemable PEMFC for the performence tests. The resulted show that Pt clusters in both catalysts are of small particle size (about 4nm), and Pt/CNTs exhibits a higher catalytic activity than Pt/C.

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Adsorption And Oxidation Of Phenol Electrode Processes, Bao-Cheng Wang, Yan-Ping Sun, Jin-Hua Zhu Nov 2003

Adsorption And Oxidation Of Phenol Electrode Processes, Bao-Cheng Wang, Yan-Ping Sun, Jin-Hua Zhu

Journal of Electrochemistry

The electrochemical behaviors of platinum electrode were studied by cyclic voltammetry in 1mol/L sulfuric acid solution and 1mol/L sulfuric acid solution contained phenol. The adsorption characteristics of phenol and the intermediat on electrode surface have been discussed. The reactive reversibility and oxidation mechanism of phenol on electrode process have been investigated.The potential of characteristic adsorption was suggested. The various products woud be formed when the electrode potential was greater than the one of characteristic adsorption.

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Synthesis And Electrochemical Properties Of K2Feo4, Ning Zhou, Shi-Hai Ye, Yong-Long Wang, Xue-Ping Gao, Dong-Feng Lin, Zuo-Xiang Zhou, De-Ying Song Aug 2003

Synthesis And Electrochemical Properties Of K2Feo4, Ning Zhou, Shi-Hai Ye, Yong-Long Wang, Xue-Ping Gao, Dong-Feng Lin, Zuo-Xiang Zhou, De-Ying Song

Journal of Electrochemistry

The K2FeO4 used for new positive electrode materials was prepared. The primary batteries were used in different concentration of electrolyte and different currents. In 9 mol/L KOH , the capacity was the best. The higher the concentration of electrolyte, the lower the electric potential was. When the batteries discharged in 0.4 C , the capacity reached 521.3 mAh/g. By XRD, we gave the reasonable explanations for the discharge products of K2FeO4. Possible mechanism of discharge is discussed.

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Comparison Of Thermal Cyclic Oxidation Of The Pvd Ni-Al And Hvof-Mcraly Coatings, J-T Chang, C-H Yeh, J-L He, K-C Chen Aug 2003

Comparison Of Thermal Cyclic Oxidation Of The Pvd Ni-Al And Hvof-Mcraly Coatings, J-T Chang, C-H Yeh, J-L He, K-C Chen

Journal of Electrochemistry

A PVD process-cathodic arc plasma ion plating was used to deposit Ni-Al films on Inconel 600 superalloy. The oxidation behaviors of PVD Ni-Al coating and the thermal sprayed CoCrAlY coatings were revealed and compared by performing cyclic thermal oxidation test at 1100 ℃ to evaluate its feasibility. Experimental results showed that the films with different compositions of Ni62Al38, Ni63Al37 and Ni69Al31 could be obtained when using Ni52Al48, Ni60Al40 and Ni70Al30 as targets, respectively. During the cyclic thermal oxidation test, the …

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Synthesis Of Polyunit Vapor Phase Inhibitor And Its Volatile Corrosion Inhibition Performance, Da-Quan Zhang, Li-Xin Gao, Guo-Ding Zhou Aug 2003

Synthesis Of Polyunit Vapor Phase Inhibitor And Its Volatile Corrosion Inhibition Performance, Da-Quan Zhang, Li-Xin Gao, Guo-Ding Zhou

Journal of Electrochemistry

A Mannich Base derivative (BMMCH), containing two morpholinum moieties and one cyclohexylamnonium moiety, was synthesized through aminomethy1 reaction. Its configuration was verified by IR and 1H-NMR. Its volatile rustproofing effect was appraised by volatile rustproofing sieve test and vapor inhabitability test. The result shows that BMMCH has good protection effect for carbon steel. BMMCH has lower volatility compared with dicyclohexylamnonium nitrite (DICHAN) via closed space volatile weight-loss test. The inhibition mechanism was studied by potentiodynamic polarization electrochemistry technique in ASTM simulated atmospheric water. The corrosion potential of carbon steel electrode shifted to a negative direction when BMMCH was joined …

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The Mechanism Of Electrocatalytic Reduction Of Oxygen On Manganese Dioxide, Yu-Liang Cao, Han-Xi Yang, Xin-Ping Ai, Li-Fen Xiao Aug 2003

The Mechanism Of Electrocatalytic Reduction Of Oxygen On Manganese Dioxide, Yu-Liang Cao, Han-Xi Yang, Xin-Ping Ai, Li-Fen Xiao

Journal of Electrochemistry

The oxygen electroreduction on the MnO2 electrode was investigated by analysis of the polarzation properties of oxygen reduciton and its dependence on MnO2 discharge state, in combination with the characterization of discharge intermediate and the kinetic parameters of the oxygen reduction. Based on the experimental observation and mechanistic analysis, it was suggested that the reduction of oxygen was closely related to the discharge behaviors of MnO2. When MnO2 was electrochimically reduced to MnOOH, it was immediately oxidized by oxygen molecules. Thus the oxygen reduction proceeds through continuous oxidation of the discharge product of MnO2 …

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Electrochemistry And Electrocatalysis Of A Novel Μ-Oxamido Copper(Ⅱ) Binuclear Complex, Gui-Lian Gao, Guo-Bao Li, Qiu-Xia Yang, Xue-Lin Wang Aug 2003

Electrochemistry And Electrocatalysis Of A Novel Μ-Oxamido Copper(Ⅱ) Binuclear Complex, Gui-Lian Gao, Guo-Bao Li, Qiu-Xia Yang, Xue-Lin Wang

Journal of Electrochemistry

In this paper, the cyclic voltammetric and spectroelectrochemical behaviors of μ-oxamido Copper(Ⅱ) Binuclear Complex (deCu) in PBS were studied. Cyclic voltammograms of this complex in PBS (pH=9) exhibited two reductive peaks (Epc1 =-0.25 V, Epc2 = -0.50 V) at hanging mercury drop electrode(HMDE), peaks at -0.50 V and -0.25 V corresponded to the reduction of ligand and copper(Ⅱ) complex, respectively. The spectroelectrochimical experiments showed that there was a new absorption band at 440 nm, and the absorption peaks at 270 nm, 280 nm red shifted to 300 nm, 310 nm under potential of -0.75 V. It was meant …

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Diffuser Optimation At Exhaust System With Catalytic Converter For 110 Cc Mopet With Fluid Flow Cfd Simulation, Tresna P. Soemardi, Ahmad Indra Siswantara, Erwin Erwin Aug 2003

Diffuser Optimation At Exhaust System With Catalytic Converter For 110 Cc Mopet With Fluid Flow Cfd Simulation, Tresna P. Soemardi, Ahmad Indra Siswantara, Erwin Erwin

Makara Journal of Technology

Diffuser Optimation at Exhaust System with Catalytic Converter for 110 cc Mopet with Fluid Flow CFD Simulation. CFD simulation used to get behavior of exhaust gas through catalyst, this result will be used to optimize geometry form to perform uniform stream distribution to catalyst, and CFD Simulation will used to analyze backpressure that happened at the model.

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The Study On Fluorescence Characteristics Of Chlorella Spp: Ph Influence On Culture, Retno Wigajatri P., Andrianto Handojo, Hendrik Kurniawan, N. B. Prihantini Aug 2003

The Study On Fluorescence Characteristics Of Chlorella Spp: Ph Influence On Culture, Retno Wigajatri P., Andrianto Handojo, Hendrik Kurniawan, N. B. Prihantini

Makara Journal of Technology

The Study on Fluorescence Characteristics of Chlorella spp: pH Influence on Culture. Experiments for measuring the fluorescence characteristics of Chlorella spp. by using high stability and high repetition rate nitrogen laser of energy 5 mJ with pulse duration of 5 ns have been carried out. The results show that for a cell concentration range from 2,625 cells/ml up to 2,769,000 cells/ml, the fluorescence intensities at pada λ = 687 nm have a linear relationship with the cell concentration. It has been also found that for a 7 days old chlorella culture, the pH variation at the starting culture influenced the …

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Capacity Of High-Speed Powerline Communication In Vehicles, Deny Hamdani, Ery Safrianti Aug 2003

Capacity Of High-Speed Powerline Communication In Vehicles, Deny Hamdani, Ery Safrianti

Makara Journal of Technology

Powerline Communication (PLC) Systems intents to use the mains network in vehicles for high-speed data transmission. Carrier frequencies in the range of MHz are required to establish data rates of some megabits per second. In this paper, typical reference channels extracted from channel measurements are presented and computation results of their capacities according to Shannon’s theorem are presented. Furthermore, the effect of limitations of frequency range and power spectral density of transmitted signal on achievable capacity is investigated. This paper outlines an assessment for theoretical channel capacity and achievable data rates of vehicular PLC transmission schemes. Finally, EMC (Electromagnetics Compatibility) …

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The Performance Analysis Of A Unicast Network When Two Protocols, Sctp (Stream Control Transmission Protocol) And Tcp (Transmission Control Protocol) Coexist In The Network, Bagio Budiardjo, Michael Thiotrisno Aug 2003

The Performance Analysis Of A Unicast Network When Two Protocols, Sctp (Stream Control Transmission Protocol) And Tcp (Transmission Control Protocol) Coexist In The Network, Bagio Budiardjo, Michael Thiotrisno

Makara Journal of Technology

This paper elaborates the performance analysis of a unicast network when two protocols, SCTP (Stream Control Transmission Protocol) and TCP (Transmission Control Protocol) coexist in the network. These two protocols are tested using File Transfer Protocol (FTP) and Constant Bit Rate (CBR) based traffic. From the simulations, it could be concluded that SCTP could achieve better throughput compared to TCP in both FTP and CBR based traffic, with sufficiently high fairness index of both intrafairness and interfairness. The increase of simulation time yields to the increase and relatively stable network performance. The increase of the number of sessions of small …

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Mapping Of Ecosystems In Mount Bromo Using Remote Sensing Technology, Bangun Muljo Sukojo Aug 2003

Mapping Of Ecosystems In Mount Bromo Using Remote Sensing Technology, Bangun Muljo Sukojo

Makara Journal of Technology

Mapping of Ecosystems in Mount Bromo Using Remote Sensing Technology. Covered land analyses of Landsat image have been done to get ecosystem types and map in Mount Bromo region using remote sensing technology. There are nine types of ecosystems in Mount Bromo region, i.e. primary forest, secondary forest, lake, crater, sands, uncovered land, underbrush, dry-field and residence. Distribution of rock analysis has also been done by comparing the manual image interpretation with geological map. The results were coorelated with the digital image interpretation to find rock distribution map which can be useful to get the information about water reservation potencial …

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Oxidation Behavior Of Zr-Cu-Al-Ni Amorphous Alloys In Air At 300～500℃, H. H. Hsieh, W. Kai, T. G. Neih, Y. Kawamura May 2003

Oxidation Behavior Of Zr-Cu-Al-Ni Amorphous Alloys In Air At 300～500℃, H. H. Hsieh, W. Kai, T. G. Neih, Y. Kawamura

Journal of Electrochemistry

The oxidation behavior of the Zr- based bulk amorphous alloy (BMG; Zr-30Cu-10Al-5Ni in at.%) was studied in dry air over the temperature range 300～500 ℃. The kinetic results indicated that the amorphous alloy oxidized linearly at 300 ℃, while the parabolic oxidation was observed at 350～425 ℃, and the oxidation behavior at 500 ℃ was irregular and complicated. In general, the scales formed on the surface of the amorphous alloy were temperature-dependent, consisting of tetragonal-ZrO2 at 300 ℃, and of mostly tetragonal-ZrO2 as well as minor amounts of monoclinic-ZrO2 and CuO at T ≥ 350 ℃.

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Synthesis And Electrochemical Characteristics Of Nickel-Based Complex Oxide LiANi0.78Co0.2Cd0.02O2, Rong-Zhong Yuan, Mei-Zhen Qu, Zuo-Long Yu May 2003

Synthesis And Electrochemical Characteristics Of Nickel-Based Complex Oxide LiANi0.78Co0.2Cd0.02O2, Rong-Zhong Yuan, Mei-Zhen Qu, Zuo-Long Yu

Journal of Electrochemistry

The nickel-based complex oxide LiaNi0.78Co0.02O2 cathode materials for lithium-ion rechargeable batteries was synthesized by the improved solid-state reaction method with LiOH·H2O, ball-like Cd-doped Ni(OH)2 and Co2O3 as raw materials. The analysis ICP-AES proved that the as-prepared compounds were near the stoichiometric form. The XRD, SEM and electrochemical characteristics testing were also carried out. The results showed that the complex cathode material LiaNi0.78Co0.2Cd0.02O2 has layered structure, homogeneous surface distributions,uniform particles with good crystal morphology as well as stable electrochemical …

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Electrochemical Monitoring On The Deactivation Of A Metallic Oxide Anode, Li-Kun Xu, Shi-Zhe Song, Ting-Yong Wang, Guang-Zhang Chen May 2003

Electrochemical Monitoring On The Deactivation Of A Metallic Oxide Anode, Li-Kun Xu, Shi-Zhe Song, Ting-Yong Wang, Guang-Zhang Chen

Journal of Electrochemistry

The process of accelerated life test of an IrO2/Ta2O5 coated titanium anode was monitored using cyclic voltammetry and electrochemical impedance spectroscopy. The vatiation with electrolysis time of anodic voltammetric charge Q*, the double layer capacitance Cdl,the oxide film resistance Rf and the charge transfer resistance Rct for oxygen evolution was measured. A deactivation mechanism was proposed based on the observation results.

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Development And Analysis Of Geographic Information System For Electricity Network (Case Study: Surabaya Industrial Estate Rungkut In Surabaya)., Lilik Jamilatul Awalin, Bangun Muljo Sukojo Apr 2003

Development And Analysis Of Geographic Information System For Electricity Network (Case Study: Surabaya Industrial Estate Rungkut In Surabaya)., Lilik Jamilatul Awalin, Bangun Muljo Sukojo

Makara Journal of Technology

Development and Analysis of Geographic Information System for Electricity Network (Case Study: Surabaya Industrial Estate Rungkut in Surabaya). Geographic Information System (GIS) is a system of data which has spatial base. This may be cause has ability to process and analysis data quickly. The ability of GIS will be able to process the alternative in decision making. The need of electric power grows until recent time along with the existence of industrial sector expansion and land use expansion claim better service, large and balance stock of electric power. GIS is a solution for planning and managing data base system, for …

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Application Of Remote Sensing And Geographic Information System Methods For Land Using Difference, Bangun Muljo Sukojo, Diah Susilowati Apr 2003

Application Of Remote Sensing And Geographic Information System Methods For Land Using Difference, Bangun Muljo Sukojo, Diah Susilowati

Makara Journal of Technology

Application of Remote Sensing and Geographic Information System Methods for Land Using Difference. Land using difference analysis has been done using remote sensing and Geographic Information System (GIS) methods. Identification of land using difference was conducted using map overlaying process of 1990s (digitized scalling 1:50.000) and 1997s land using map (interpreted from Landsat TM (Thematic Mapper) Image 1997) with UTM (Universal Transverse Mercator) coordinate. Image enhancement was done through histogram equalization with supervised classification devided into 7 classes: rice field, settlement, dry field, industry, pond, sport field and bush. Land using difference and river pollution BOD (Biological Oxygen Demand), COD …

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Influence Of Strain Rate And Temperature Of Hot Tension Testing On Mechanical Properties Of Medium Carbon Steel S48c, Dedi Priadi, Iwan Setyadi, Eddy S. Siradj Apr 2003

Influence Of Strain Rate And Temperature Of Hot Tension Testing On Mechanical Properties Of Medium Carbon Steel S48c, Dedi Priadi, Iwan Setyadi, Eddy S. Siradj

Makara Journal of Technology

Influence of Strain Rate and Temperature of Hot Tension Testing on Mechanical Properties of Medium Carbon Steel S48C. The characterization of S48C by hot tension testing was done to understanding the influence of temperature and strain rate for S48C flow stress, that close relationship with its forge ability. The hot tension testing was performed on temperatures and strain rates variation (T 850, 900, 950 0C and έ 0,01;1 s-1). The result of hot tension testing showed that increasing temperature decreases ultimate tensile strength (UTS) and flow stress of S48C. The higher decreasing of UTS is on 950 0C about 85% …

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Phase Composition Analysis Using Rietveld Methode And It's Influence To The Hardness Of Ti-Si-N Nanocomposites, Keba Moto, Lia Setiarini, Zufar Abubakar Apr 2003

Phase Composition Analysis Using Rietveld Methode And It's Influence To The Hardness Of Ti-Si-N Nanocomposites, Keba Moto, Lia Setiarini, Zufar Abubakar

Makara Journal of Technology

Phase composition analysis using rietveld methode and it’s influence to the hardness of Ti-Si-N nanocomposites. XRD data of nanocomposites Ti-Si-N have been analysed using GSAS based on Rietveld Method in order to identify phases and their composition as well as its influence on the hardness of these nanocomposites. Several new phases have been found in the sample beside the nc-TiN/a-Si3N4& a-/nc-TiSi2 that have been known widely. From the obtained crystalline phase, after the calculation of amorf Si3N4 and TiSi2 phase fraction, it is found that the optimum hardness can be reached when the fraction of a-Si3N4 phase around 8 wt.%

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Study About High Influence Doping To Base Resistance And Bandgap Narrowing At Si/Si1-Xgex/Si Heterojunction Bipolar Transistor, Achmad Fadhol Apr 2003

Study About High Influence Doping To Base Resistance And Bandgap Narrowing At Si/Si1-Xgex/Si Heterojunction Bipolar Transistor, Achmad Fadhol

Makara Journal of Technology

Study About High Influence Doping to Base Resistance and Bandgap Narrowing at Si/Si1-xGex/Si Heterojunction Bipolar Transistor. Heterojunction is a link formed bedween two semiconductor materials and differend bandgap which has thinness under 50nm and grow the mixture of plate SiGe as bases. The link is an abrupt link or graded one. In this research learnt formulation of doping concentration influence to basis resistance and bandgap narrowing through Si/Si1-xGex/Si Heterojunction Bipolar Transistor with abrupt emitter-basis link, besides taking care to mobility and basis wide to basis resistance, it is also influence of mole fraction to bandgap power. From the result shows …

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