Engineering Commons^™

Microemulsion Preparation And Electrochemical Characterization Of Pt/C，Ptir/C Electrocatalysts, Ya-Ping Zeng, Sheng Sui

Journal of Electrochemistry

The Pt/C electrocatalysts were prepared by three different systems and the PtIr/C electrocatalysts were prepared with four different Ir contents. The samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), cyclic voltammetry (CV), potentiostatic and potentiodynamic polarizations measurements. The experimental results confirmed that the electrocatalyst particles prepared by the microemulsion method were well distributed on XC-72R supports with the active particle sizes of 5～10nm and good electrocatalysts activity. The Pt85Ir15/C electrocatalysts showed the highest overall electrochemical activity in unitized regenerative fuel cell.

Electrochemical Properties Of Tungstogermanate And Electrocatalysis Of H2o2 On Gew11co/P-Opd/Gc Electrode, Li-Li Zhu, Jian-Ying Qu, Jue Wang, Hao-Yue Feng

Journal of Electrochemistry

The electrochemical properties of Co-substituted trimeric tungstogermanate containing Keggin fragments were studied. Cyclic voltammograms revealed two couples of reversible redox peaks on glassy carbon (GC) electrode in acid solutions. They corresponded to two-electron reductions accompanying by the additions of four protons and three protons, respectively, both were controlled by adsorption. The differences in the peak potentials of 2-electron-4-proton and 2-electron-3-proton reactions were 31 mV and 35 mV, respectively..Furthermore, the tungstogermanate (GeW11Co) modified GC electrode with functionalization by poly(o-phenylenediamine) (P-oPD) was prepared readily by electropolymerization. The GeW11Co/P-oPD/GC electrode could electrocatalyze the reduction of hydrogen peroxide, which showed good stability and quick …

Preparation And Characterization Of The Lani0.6fe0.4o3-Δ Cathode For Intermediate Temperature Solid Oxide Fuel Cell, Hang Liu, Bo Huang, Xin-Jian Zhu

Journal of Electrochemistry

The LaNi0.6Fe0.4O3-δ as cathode material for intermediate temperature solid oxide fuel cell was prepared using a combustion synthesis technique. The X-ray diffraction (XRD) pattern showed that the single-phase LaNi0.6Fe0.4O3-δ perovskite could be obtained after heat treatment at 600°C. The TEM and SEM images of the synthesized powders revealed that the grains were 50-100nm. According to the electrochemical impedance spectra (EIS), the polarization resistance of the symmetric cell LaNi0.6Fe0.4O3-δ/ScSZ/LaNi0.6Fe0.4O3-δ sintered at 1050°C was the smallest (0.70Ω?cm2, 0.27Ω?cm2 and 0.12Ω?cm2 at 750°C, 800°C and 850°C, respectively). In the presence of the Fe-Cr alloy interconnection at 750°C, the cathode performance showed that, with …

Dynamic Modeling And Characteristic Analysis Of Proton Exchange Membrane Fuel Cell, Qiu-Hong Jia, Ming Han, Bin Deng, Cai-Zhi Zhang

Journal of Electrochemistry

In this paper, a dynamic model of PEMFC is developed to estimate the dynamic performance of PEMFC by analyzing in detail the influence factors of voltage of PEMFC including various losses. The partial pressure of hydrogen and oxygen is obtained using the differential form of the ideal-gas equation in this model. The steady-state model is obtained by setting reasonable parameter values. The simulation results and experimental results have good consistency, which shows that the simulation model is correct, reasonable and effective. It analyzed the dynamic response characteristics of the output voltage and the partial pressure of hydrogen in condition of …

Indirect Electrochemical Reduction And Cotton Dyeing Process In Fe(Ⅲ)-Oxalate-Calcium Gluconate System, Qing-Zhi Wang, Wei Wang

Journal of Electrochemistry

The electrochemical behavior and possible reaction mechanism in Fe(Ⅲ)-oxalate-calcium gluconate system were studied by cyclic voltammetry. The results showed that Fe(Ⅱ)-gluconate was the final reductant. The reduction time, the working voltage and the cathode area influenced the current efficiency. The high current efficiency of 89% for the indirect electrochemical reduction of Vat Scarlet R could be achieved with reduction time of 10 min, working voltage of 4 V and cathode area of 40 cm2 in Fe(Ⅲ)-oxalate-calcium gluconate system.

Preparation And Capacitance Characteristics Of Nickel Oxide Electrode With Mesh-Like Structure, Hui Xu, Zhen-Jun Peng, Dong-Hong Guo, Jun-Ling Li

Journal of Electrochemistry

The mesh-like structure of NiO electrode was obtained by first preparing the precursors via hydrothermal process using nickel sulfate and carbamide as reactants, sodium hexametaphosphate as a surfactant, and followed by calcination of the precursors at 400 ℃. The structure, morphology and capacitance characteristics of NiO electrode were characterized by XRD, SEM and constant current charge-discharge testing techniques. The effects of hydrothermal temperatures on the electrochemical properties of NiO electrode were investigated. The results showed that the better property of nickel oxide was obtained when the mole ratio of nickel to urea was 1:4 and the hydrothermal temperature was 140℃. …

Optimation Of Nitrogen And Phosphorus In Azolla Growth As Biofertilizer, Hany Handajani

Makara Journal of Technology

Nitrogen is one of the most important minerals for living organisms. Azolla is known as a small water fern which can fix nitrogen through the symbiotic association with the blue green algae Anabaena. Experimental studies were carried out in the glass house, investigating the growth of Azolla using different levels of nitrogen and phosphorus in the media. The experiment used 12 treatments with 3 levels of nitrogen (0, 5, and 10 mg atom/L) and 4 levels of phosphorus (0, 10, 20, and 30 mg atom/l) in a factorial design with 3 replicates. The results show that the highest biomass for …

Establishment Code Hand Palm (Palm Code) 2d Gabor-Based Method, I Ketut Gede Darma Putra, Wira Bhuana, Erdiawan Erdiawan

Makara Journal of Technology

Establishment Code Hand Palm (Palm Code) 2D Gabor-Based Method. Palmprint is relatively new in physiological biometrics. Palmprint ROI segmentation and feature extraction are two important issues in palm print recognition. This paper introduces two steps in the center of mass moment method for ROI segmentation that will be applied in the Gabor 2D filter to obtain palm code as palmprint feature vector. Normalized Hamming distance was used to measure the similarity degrees of two feature vectors of palmprint. The system was tested using database 1000 palmprint images generated from 5 samples from each of the 200 persons randomly selected with …

Antibacterial Activity Of Papaya Leaf Extracts Against Pathogenic Bacteria, Elisa Friska Romasi, Jessica Karina, Adolf Jan Nexson Parhusip

Makara Journal of Technology

It was reported that the extracts of papaya leaves could inhibit the growth of Rhizopus stolonifer. Antibacterial activity of Carica papaya leaf extracts on pathogenic bacteria was observed in this study. Papaya leaves were extracted by using maceration method and three kinds of solvents: ethanol, ethyl acetate, and hexane. Papaya leaf extracts were tested against Bacillus stearothermophilus, Listeria monocytogenes, Pseudomonas sp., and Escherichia coli by agar diffusion method. The objectives of this study were to determine extract ability against pathogenic bacteria, to observe the influence of pH, NaCl, and heat on extracts ability, and to observe extract ability against B. …

Analytical And Computational Simulation Approaches To Design Low Energy Glass Block, Floriberta Binarti, Agustinus Djoko Istiadji, Prasasto Satwiko, Priyo Tri Iswanto

Makara Journal of Technology

Analytical and Computational Simulation Approaches to Design Low Energy Glass Block. An environmentally friendly process was developed to produce a low embodied energy glass block from waste glasses. The energy efficiency of the glass block is represented by its thermal conductance (U) <3.177 W/m2.K and solar transmittance (SHGC) ≤0.25 as well as visible light transmission (VT) ≥0.27. A cavity was applied to reduce U value while insignificantly reducing VT. Analytical method was used to calculate the U value of glass blocks, ignoring the effect of convection. Ecotect program was used to analyze light level (VT) and heat load (SHGC) of each model. Effect of convection was simulated using a CFD program, which showed air velocity inside the cavity and temperature gradient in glass blocks. Comparing to an application with 3 mm float glass, energy efficiency obtained through applying the glass blocks could reach 96%. This simulation study ignored the presence of adhesive among glass layers that potentially reduces the VT and the SHGC of the glass blocks.

Flexible Connection Elastomeric Rubber As A Pounding Resisting Element Between Two Adjacent Buildings, Yuskar Lase, James Jatmiko Oetomo

Makara Journal of Technology

Flexible Connection Elastomeric Rubber as a Pounding Resisting Element between Two Adjacent Buildings To solve pounding problem of two adjacent buildings, structural designer usually employs a dilatation between the structures or make the two structures as a monolith structure. Other alternative is by using an elastomeric rubber as a pounding resisting element between the two structures. Effectiveness in applying elastomeric rubber component as flexible connection of two adjacent structures is the main focus of this paper. Various simulations such as structure models, earthquake excitations and openings in gap element are studied. Observation of maximum structural responses will be performed for …

Alos/Palsar Image Processing Using Dinsar And Log Ratio For Flood Early Detection In Jakarta Based On Land Subsidences, Dodi Sudiana, Mia Rizkinia

Makara Journal of Technology

Flood that occurred in Jakarta is not only influenced by rainfall, urban planning system and drainage alone, but also may be involved land subsidence (LS). LS is possible in because Jakarta stands on top of layers of sediments and the presence of ground water consumption in very large quantities. In this research, the Advanced Land Observing Satellite (ALOS)/Phased Array type L-band Synthetic Aperture Radar (PALSAR) data was processed to determine the level of LS in Jakarta area and its relation to flood potential area. Differential interferometry method (DInSAR) was performed on two PALSAR data with different acquisition years, i.e. 2007 …

Physical Characterization And Desulfurization Of Biobriquette Using Calcium-Based Adsorbent, Mahidin Mahidin, Asri Gani, Khairil Khairil

Makara Journal of Technology

Combustion of coal and co-combustion of their co-fuel contribute to gas emissions. Among the gas emissions are SOx, NOx, CO and CO2. Introduction of calcium based adsorbent is addressed to absorb SO2 that release to the atmosphere during the combustion process. Objective of the research is at first to observe the physical characteristics of biobriquettes as a function of briquette compositions (coal to palm kernel shell ratios) and Ca/S ratios (Ca in adsorbent and S in briquette) using a natural adsorbent (shellfish waste). The second objective is to investigate desulfurization characteristics as a function of Ca/S ratios and desulfurization temperatures …

Application Of Principal Component Proximity Transform And Geostatistics Methods For Volume Shale Distribution As Reservoir Characreristic Imaging In Seismic 3d, Nur Islami

Makara Journal of Technology

Application of Principal Component Proximity Transform and Geostatistics Methods for Volume Shale Distribution as Reservoir Characreristic Imaging in Seismic 3D. Principal component proximity transform (PCPT) technique was used to predict the content of volume shale into seismic data in reservoir modeling framework. The goal in this research is to get the volume shale imaging in three dimensions and allow for reservoir modelling. The reservoir modelling requires an integrated quantitative and qualitative data sources collected separately, such as well and seismic data. Integrating PCPT and Geostatistic methods can generate the detail information for characterization of reservoir’s properties. Finally, it shows that …

Effect Of Copper Addition On Mechanical Properties And Electrical Conductivity Of Pp/C-Cu Bipolar Plate Composites, Anne Zulfia, Taufik Abimanyu, Verina Warga Dalam

Makara Journal of Technology

Effect of Copper Addition on Mechanical Properties and Electrical Conductivity of PP/C-Cu Bipolar Plate Composites. Bipolar plate is a major component in PEM fuel cell which possess main function of collecting and removing electrons from anode to cathode. Therefore, materials for bipolar plates produced must have high electrical conductivity. To obtain bipolar plate materials which is cheap, lightweight and high conductivity, so it is developed bipolar plates material based on PP/C-Cu composite. PP/C-Cu composites has been made by mixing all materials then compounding, rheomix, hot blending and hot press. Cu (Copper) has been used various from 0.1 wt%, 1 wt% …

Flutter Analysis Of Rx-420 Balistic Rocket Fin Involving Rigid Body Modes Of Rocket Structures, Novi Andria

Makara Journal of Technology

Flutter Analysis of RX-420 Balistic Rocket Fin Involving Rigid Body Modes of Rocket Structures. Flutter is a phenomenon that has brought a catastrophic failure to the flight vehicle structure. In this experiment, flutter was analyzed for its symmetric and antisymmetric configuration to understand the effect of rocket rigid modes to the fin flutter characteristic. This research was also expected to find out the safety level of RX-420 structure design. The analysis was performed using half rocket model. Fin structure used in this research was a fin which has semispan 600 mm, thickness 12 mm, chord root 700 mm, chord tip …

Medium Density Fibreboard Made Of Acetylated Sludge From Paper Mill, Luthfi Hakim, Evalina Herawati, I Nyoman Jaya Wistara

Makara Journal of Technology

Medium Density Fibreboard Made of Acetylated Sludge from Paper Mill. Research of using sludge as raw material for making medium density fibreboard (MDF) was useful to create additional value of sludge. The objective of the research was to evaluate physical properties, mechanical properties, and durability of MDF from acetylated sludge in 4 levels of acetate anhydride (0%, 3%, 5%, and 7%) with 3 replicates. The MDF was made using dry process. After materials were mixed with adhesives, they were pressed using hotpress under 170 oC temperature and 45 Pa pressure for 25 minutes. The size of the MDF sample was …

Improvement Of High Temperature Oxidation Of Low Carbon Steel Exposed To Ethanol Combustion Product At 700 °C By Hot-Dip Aluminizing Coating, Mohammad Badaruddin

Makara Journal of Technology

Low carbon steel (AISI 1005) was coated by hot-dipping into a molten Al-10% Si bath at 700 °C for 18s. After hotdipping treatment, the coating layers consisted of Al, Si, FeAl3, τ5-Fe2Al8Si, and Fe2Al5. The bare steel and the aluminized steel were isothermally oxidized at 700 °C in ethanol combustion product at atmospheric pressure for 49 h. The aluminized steel shows good performance in high temperature oxidation because the formation of Al2O3 layer on the coating surface. The growth of iron oxide nodules on the surface coating was accelerated by rapid outward diffusion of Fe-ions due to the presence of …

Application Of Empirical Orthogonal Function Models To Analyze Shoreline Change At Bangkalan Madura, Darius Arkwright, Suntoyo Suntoyo

Makara Journal of Technology

Bangkalan’s shoreline, especially on the opposite side of Surabaya, has been evaluated to determine the morphological changes due to wave attack, near-shore current, long-shore sediment transport and coastal configuration. This research aims to determine the dominant patterns of variation of Bangkalan’s shoreline change, expressed by Eigen-function in empirical orthogonal function (EOF) models. That was started with data collection such as oceanographic data (wave and tidal), bathymetry and topographic map and sediment data. All data was used for forecasting two-monthly shoreline. Coordinate of two-monthly shoreline was used as input of EOF model. The first Eigen mode is a profile of shoreline …

The Effectiveness Of Anaerobic Baffled Reactor And Rotating Biological Contactor In Batik Wastewater Treatment, Augustinus Ignatius Kristijanto, Widhi Handayani, Purwanti Asih Anna Levi

Makara Journal of Technology

Batik is one of popular arts of Indonesia. The batik industries in Sragen, Central Java, are prepared to compete in global market. In order to realize that objective, batik products should fulfill some qualifications, one of which is “environmental friendliness”. As batik production is usually generating wastewater which pollutes the environment, the technology of wastewater treatment should be developed to solve the problem. This preliminary study has been done to assess the effectiveness of anaerobic baffled reactor (ABR) and rotating biological contactor (RBC) in batik wastewater treatment. In 40 days of treatment period, the ABR performance in reducing pollutants showed …

Cassava Pulp As A Biofuel Feedstock Of An Enzymatic Hydrolysis Proces, Djuma’Ali Djuma’Ali, Nonot Soewarno, Sumarno Sumarno, Dyah Primarini, Wahono Sumaryono

Makara Journal of Technology

Cassava pulp, a low cost solid byproduct of cassava starch industry, has been proposed as a high potential ethanolic fermentation substrate due to its high residual starch level, low ash content and small particle size of the lignocellulosic fibers. As the economic feasibility depends on complete degradation of the polysaccharides to fermentable glucose, the comparative hydrolytic potential of cassava pulp by six commercial enzymes were studied. Raw cassava pulp (12% w/v, particle size <320 >μm) hydrolyzed by both commercial pectinolytic (1) and amylolytic (2) enzymes cocktail, yielded 70.06% DE. Hydrothermal treatment of cassava pulp enhanced its susceptibility to enzymatic cleavageas compared …

Evaluation Of Dye And Pigment Based Ink Jet Ink Sets, Veronika Chovancova

The Hilltop Review

The development of high performance inkjet printers and inks is advancing rapidly. Manufacturers seem to introduce their new technology inks to the market on an almost daily basis. Chemists in ink laboratories are still fighting with the issue of combining a wide gamut of dye-based inks with the lightfast and weather resistance qualities of pigment-based inks into new-age ink formulations.

Three different inkjet printers and inks were investigated in this work: the Epson Stylus® Pro 5000, using a dye-based ink set, the Epson Stylus® Pro 5500, employing Archival ink technology, and the Epson Stylus® Photo 2200, with 7-color UltraChrome™ inks. …

The Study Of Ink Pigment Dispersion Parameters, Lokendra Pal, Paul D. Fleming Iii

The Hilltop Review

The purpose of this study was to investigate the influence of rotation speed and milling time on the pigment dispersion quality. The information can be used to obtain a standard laboratory condition at which a wide range of pigments may be dispersed to formulate water-based rotogravure inks. The influence of pigment concentration and shear forces on the pigment dispersion were also studied.

The procedure consisted of dispersing the pigment using a laboratory Dispermat® SL bead mill at various milling times with two different rotation speeds and measuring the particle size and particle size distribution of the milled samples. The pigment …

Synthesis Of Limnpo4/C Used As Cathode Material For Lithium Ion Batteries, Xin Yang, Xue-Wu Liu, Gui-Chang Liu, Zhi-Cong Shi, Xin Li, Guo-Hua Chen

Journal of Electrochemistry

The LiMnPO4/C composites were prepared using a solid-state reaction with addition of the resorcinol formaldehyde resin as the carbon source. The effects of reaction temperature and time on the crystal structure, morphology and electrochemical properties of the LiMnPO4/C composites were investigated. The results show that the best performance was achieved with the LiMnPO4/C composites synthesized at 600 oC for 12 h which had the particle sizes about 100~200 nm. The initial discharge capacities were 121.6 mAh?g-1 at 0.02C, 110 mAh?g-1 at 0.1C and more than 60 mAh?g-1 at 1C. An overall reversible capacity of 110 mAh?g-1 had been retained after …

Electrochemical Performance Of Tin Dioxide/Carbon Xerogel Composites As Anode Materials For Lithium-Ion Batteries, Xiao-Jing Liu, Lin-Lin Qin, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The tin dioxide/carbon xerogel composites were synthesized by using vacuum infiltration method. Structural characterization and morphology of the composites were investigated by using XRD, TEM and SEM techniques. BET test was performed to determine the pore size distributions of carbon xerogels and the composites. The results showed that the nano-sized SnO2 particles (5~10 nm) were encapsulated in the pores of carbon xerogels. During the electrochemical tests the SnO2 in the composites exhibited capacity retention of 61.9% after 100 cycles of charge-discharge tests at 100 mA/g.

Synthesis And Electrochemical Behaviors Of Li2coxmn1-Xsio4 As A Cathode Material For Lithium-Ion Batteries, Lin Wang, Dong-Ping Lv, Yong Yang

Journal of Electrochemistry

We have successfully synthesized Li2CoxMn1-xSiO4/C (x=0, 0.1, 0.3, 0.5, 1)/C composites using hydrothermal assisted sol-gel process and ball-milling method. The results of X-ray diffraction show that the solid solutions of Li2CoxMn1-xSiO4 can be achieved when x≤0.3. The initial capacities increase from 70 mAhg-1??? of Li2MnSiO4/C to 105 mAhg-1??? of Li2Co0.3Mn0.7SiO4/C. Cyclic Voltammetry (CV) curves show that the replacement of Mn with Co can reduce the electrochemical polarization, making the insertion-extraction reaction of Li+ much easier. EIS results also prove that Co can decrease the charge transfer impedance of the materials.

Comparison Of Catalytic Performance On Different Materials Supported Pd Catalysts For Formic Acid Oxidation, Su-Dong Yang, Yan-Yu Liang, Zhu-Liang Wen, Qi-Jun Song, Xiao-Gang Zhang

Journal of Electrochemistry

Graphite oxide (GO) was prepared from by Hummers method. Then the graphene nanosheets supporting Pd catalysts were prepared by a single-step chemical reduction method. The electrocatalytic performance for formic acid oxidation of the prepared Pd/graphene composite was studied as an electrode material in comparison with the composite catalysts based on the other carbons (MWCNTs, SWCNTs, and Vulcan XC-72 carbon black). X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements indicated that the Pd nanoparticles were well dispersed on the surface of the graphene nanosheets with a small particle size. The electrocatalytic oxidation of formic acid was studied by electrochemically active …

Study On Direct Electro-Oxidation Of Anisaldehyde, Lin-Lin Wu, Ying-Hong Zhu, Shan-Shan Li, Hong-Yan Zeng, Chun-An Ma

Journal of Electrochemistry

University of Technology, Hangzhou 310032, Zhejiang,China)
Abstract: The oxidation of anisole on Pt electrode was investigated by cyclic voltammery and constant potential electrolysis. The influence of scan rates, substrate concentration, supporting electrolytes and solvent were considered . The results show that the electro-oxidation process of anisole was irreversible. In this research the sulfuric acid was the best supporting electrolytes and acetone was the best solvent, and the process was controlled by diffusion . The product of constant potential electrolysis was charactered by GC-MS .The results show that the main products was anisaldehyde, and the selectivity was up to 66.5% when …

Anode Electrodeposition Of Ti/Mno2 Electrode And Electrocatalytic Oxidization Properties Of Phenol Degradation, Ye Chen, Wen-Li Zhao, Qing Wen

Journal of Electrochemistry

Ti-base manganese dioxide (Ti/MnO2) electrode was prepared by anodically electrodeposition technology in this paper. The structure of the electrode, the microstructure of the electrode surface and the element composition of the electrode were analyzed by XRD, SEM and EDS. The preparation process parameters of the electrode were studied in detail with the help of the V~logi curve and phenol degradation curve. The Ti/MnO2 electrode was anodically electrodeposited at current density 4mA•cm-2, the Mn2 + ions concentration 0.5mol•L-1 and temperature70℃. The V~logi curve and phenol degradation curve were used to evaluate electrocatalytic oxidization properties of the electrode with phenol as the …

Synthesis And Catalytic Property Of Flaked Spindle-Like Cuo Nanocrystals, Jian-Feng Fan, Li-Qing Li, Yu-Feng Huang, Lou-Zhen Fan

Journal of Electrochemistry

A simple and efficient electrochemical route was developed for the synthesis of flaked spindle-like CuO nanocrystals using aqueous electrolyte and Cu sacrificial anode (graphite as the cathode) in an undivided cell at a constant potential mode under room temperature. The morphologies, structure and component of CuO nanocrystals obtained were characterized by SEM, XRD, respectively. Flaked spindle-like CuO nanocrystals were successfully used to modify a GC electrode to detect H2O2 with cyclic voltammetry (CV) and amperometric (AC).The results showed that products were pure monoclinic CuO nanocrystals. The linear range for the determination of hydrogen peroxide is from 1.0 μmol?L-1 to 1.0 …