Papers by Keyword: Electrode

Abstract: Welding is basic part of the most modern assembly and manufacturing operations. Shielded metal Arc Welding process has hard facing and fabrication job application due to low cost electrode, increasing alloy transfer efficiency and low dilution with substrate without losing production capacity. SMAW electrode is coated with metal mixture called flux, which on decompose produce gases to restrict weld contamination, generating deoxidizers to disinfect the weld. The choice of electrode for SMAW lies on a number of factors, like weld material, welding direction and the preferred weld properties. The present paper investigate the microstructure and hardness properties of the Low carbon steel pipe welded using shielded metal arc welding with different electrode combinations.

Abstract: We have investigated the influence of the modes of adaptive pulse-arc welding and surfacing on the structure and physical-mechanical properties of welded joints of steel 09Mn2Si and the surfaced composition of this steel coated with a modified powder material of chromium carbide with the submicrocrystalline structure. It is shown that the pulsed mode of welding and surfacing can improve the homogeneity of the structure of the welded joint of steel and a surfaced coating and reduce the grain size of metals in both of them. Structural changes lead to an increase in ductility and toughness of the weld metal.

Abstract: An alkaline fuel cell (AFC) is a device that converts the chemical energy of a fuel directly into electrical energy and heat. Efforts to improve the performance of the AFC is continuously conducted, and one of the work that has been investigated in this study was to examine the effect of the use of stainless steel as an electrode in the AFC. More specifically, this study focuses on to the influence of the thickness of the stainless steel plates used as an electrode. During the experiments, the design of the AFC with a particular dimension has been prepared with the flow of hydrogen enters at the anode and the flow of oxygen enters at the cathode at a certain pressure. Potassium hydroxide (KOH) is used as an electrolyte with a particular concentration dissolved in the water. The experiment results showed that the variation in the thickness of the stainless steel plates used as an electrode significantly affect the performance of the AFC. Similar results were also obtained for the effect of KOH concentration in the electrolyte also provide significant impact on the performance of the AFC, especially from the electrical voltage and current obtained during the experiment.

Abstract: Carbon electrodes have been successfully synthesized and characterized for desalination system based on Capacitive Deionization (CDI) technology. The carbon electrodes were synthesized with an activated carbon (700 – 1400 m²/g), carbon black, glutaric acid and polyvinyl alcohol as a binder using cross-linking method at 120 °C. The study was to investigate salt removal percentage value of 0.1 M NaCl, MgCl and KCl using CDI cell. A solution with 0.1 M was supplied to the cell using a Boyu Submersible pump (model SP-601) at a flow rate of 10 mL/min. When potentials of 1.0, 2.0, and 3.0 V were applied to the CDI cell, the result showed that a solution of 0.1 M KCl has greater salt-removal percentage than the solutions with 0.1 M NaCl and MgCl. The salt-removal percentage of KCl was achieved at 55% for 3.0 V whilst resulted in 20 and 30% for NaCl and MgCl, respectively.

Abstract: Physical parameters effects are considered as sticking point to increase and decrease the electrode performance for PEMFCs, which is related to the electrode structural degradation under diverse operating conditions, such as various air and hydrogen pressures, humidifier temperatures, and air and hydrogen flow rates. The operating for electrode prepared with 20 wt% Pt loaded 0.3 mg_Pt/cm² in single cell (25 cm²) showed that diverse parameters as pressures, humidifier temperatures, flow rate of air /hydrogen have an effects on the electrode performance. Results show better power density for high pressure, high air flow rate, and for low humidifier temperature, low H₂ flow rate. The increase in pressure ratio results increases in the current density and power density from 91.96 to 99.96 mA/cm² and from 32.56{mW/cm²} to 35.48 {mW/cm²} for an air/H₂ ratio of 1/0.5 bar and 3/2 bar, respectively. The hydrogen and air flow with the stoichiometry coefficient ratio 2/1 is the best value to achieve better performance by a flow rate of 0.3 L/min for H₂ and 0.6 L/min for air, which correspond to a current density and power density of 103.96{mA/cm²} and 31.56{mW/cm²}.

Abstract: The traditional supercapacitor is made of activated carbon, which shows lower specific capacity and higher resistance. In this paper, we demonstrated preparation of high performance supercapacitor electrode materials based on activated carbon and conducting polymer polypyrrole (ppy). In order to obtain well dispersion of ppy in activated carbon for lower resistance of electrode, a high-speed agate beads milling process was used to mix the ppy and porous carbon powder. By controlling the synergistic effect between ppy and activated carbon, a uniform structure composite electrode was prepared and the performance of this composite based supercapacitor was investigated. Compared with pure activated electrode, the obvious electrochemical performance improvement was achieved in composite electrode after the introduction of ppy. It has been found that electrode based on this composite has a maximum specific capacitance about 159 F/g, which was higher than pure activated carbon, and exhibited low resistance about 3.35 Ohm. The cycle performance results revealed that a 142 F/g (more than 88% of initial capacitance) capacitance was kept in composite electrode after 1000 cycles charge/discharge process. We conclude that the excellent synergistic effect between activated carbon and ppy resulted in superior electrochemical performance of composite electrode. Furthermore, the simple preparing method of composite electrode for supercapacitor assembly has potential commercial applications.

Abstract: Polymeric poly (vinyliden fluoride) (PVDF) is nontoxic. It possesses a better mechanical flexibility and requires a lower synthesis temperature, as compared to the piezoceramic counterparts. In order to achieve a competitive advantage against the current piezoelectric sensor, graphite could replace a more expensive silver-palladium as the electrodes for the piezoelectric PVDF. This paper reports the preliminary results on the synthesis of steel-supported graphite-PVDF/PVDF/graphite-PVDF composite films using the two-step process, consisted of the electrophoretic deposition (EPD) and heat treatment. The composite films were characterized by means of the optical microscopy, scanning electron microscopy, X-ray diffraction and differential scanning calorimetry. The heat treated graphite-PVDF electrode deposited by EPD provides adequate mechanical strength for the subsequent depositions of pure PVDF layer and the second layer of graphite-PVDF composite electrode. However, the final heat treatment stage did not eliminate the fine and large cracks of the composite film, which might be attributed to high residue stresses and weak bonding between graphite and PVDF particles in the post-heat treated composite films. Nevertheless, the increase in final heat treatment temperature of the composite film at Stage 3 improved the graphite and PVDF grain alignment, as well as its crystallinity.

Abstract: Highly (100)-oriented LaNiO₃ (LNO) thin films were prepared on p-type Si (100) substrates by metal organic solution deposition (MOSD). The LNO thin films were driven by series precursor solutions with different ratio of acetic acid to deionized water (R_aaw) and pH values. The dependences of viscosity, pH value and the thermal property of the gel-derived powders of the precursor solution on R_aaw values were systematically investigated. AFM images showed that R_aaw can dramatically influence the surface roughness. When R_aaw changed from 7:1 to 1:1, the surface roughness decreased from 3.695 nm to 1.488 nm. The resistivities of all the films are less than 2.1×10^-3Ω·cm. It shows that the precursor solution has strong effect on the microstructure of the thin films and relatively slight effect on the resistivity.

Abstract: The plasma cutting technology has been emerged as a developing technology which finds tremendous potential in fabrication and metal cutting industries. Thus for the cutting operation, the electrode inside the plasma torch plays a vital role for the plasma arc generation. The temperature of the arc is very high and at the electrode is around 3500°C. The cutting torch requires proper cooling system in order to prevent the electrode from quick wear due to the existence of high thermal gradient. The presented work aimed to study the impact of three coolants propylene glycol, ethylene glycol and de-ionized water flow over the electrode life. The experimental setups were arranged to study the heat transfer capabilities of the three coolants for different flow values and aimed to achieve the optimal flow rates for the efficient heat removal. The electrode life test trials were conducted to measure the electrode life for the flow values of three coolants in the temperature rise test. The optimal flow rates arrived from temperature rise test and the electrode life measured from life test are compared for the three coolant cases considered.

Abstract: The performance of the electrode is the core technology of the electrolytic process of seawater pretreatment, and has the decisive influence on the systematic technological process and water quality. In the initial stage of electrolytic technology being applied in seawater pretreatment, soluble anodes, which use the aluminum, ferrum or other metal elements as the main ingredient, are chosen for most cases. And this method can effectively reduce the turbidity of raw seawater and sludge density index (SDI). While applying a variety of methods, the proportion of electrolytic aluminum, ferrum and other metal elements in the water can be effectively controlled. And this can increase the ratio of hydrolysate, but will also introduce the composition of soluble electrode into the seawater inevitably. At the same time, the use of soluble electrode will be consumed continuously with the production process, which is likely to add the cost of production. This study uses electrodes which contain a variety of precious metal (such as Ti, Ru, and Ir) oxide in the seawater pretreatment process, which is different from traditional chlor-alkali industry.