![]() showed that the resistance of ITO-Ag-ITO layers did not increase significantly, while pure ITO subjected to the same treatment showed a sevenfold increase in sheet resistance. By performing bending tests where the substrate is bent to a certain radius and stretched again, Lewis et al. This approach not only decreases the sheet resistance but also improves the mechanical stability because thinner layers are possible. substituted the single-layer system of ITO by the three-layer system ITO-Ag-ITO, thus reducing the sheet resistance below 16 Ω □ −1 while retaining transmission values above 80% at 550 nm. For sputtering processes on flexible, polymeric substrates, such high temperatures are not possible, which results in higher sheet resistances. To produce ITO with low sheet resistances, high temperatures are required. In most devices, ITO is used as transparent electrode. Steim, in Comprehensive Renewable Energy, 2012 1.20.5.2 Electrodesīoth cathode and anode are prone to degradation during storage and operation of the device. Thus, it is advisable to develop a membraneless design that could help overcome these limitations. The cost of construction is also increased if membranes are employed in the MEC designs. Furthermore, membrane fouling, if persists, can also aid in ohmic losses and can hinder the HER occurring at the cathode. They increase the internal resistance of the system, cause pH imbalance between the two electrodes, and thus lead to lower current densities at a given applied voltage. However, using membranes has shown a negative impact on the performance of MECs as described in the previous section. Apart from purity, another major advantage of using membrane is that it reduces the crossover of fuel and reduces the risk of short circuit. The most common membranes used are proton-exchange membranes, anion-exchange membranes (AEM), bipolar membranes, charge mosaic membranes, etc. The anode and cathode of MECs are separated using ion-exchange membranes to maintain the purity of hydrogen gas and further restrict the anodic bacteria to consume the electrochemically produced hydrogen. Debabrata Das, in Microbial Electrochemical Technology, 2019 5.7.5.1.3 Membrane ![]() Insignificant negative peaks are observed through the test, plus a larger peak at 340 s indicating the presence of a large droplet at this location ( Fig. The corresponding sensor detected occurrence of only a few droplets. Moreover, the cell operating conditions had been selected so that the gas was slightly oversaturated in the middle of the cell. Unclogging of liquid droplets allows transient recovery of the cell performance before liquid water gradually again clogs the channel, resulting in a slow decrease in the cell voltage. The three significant peaks of the outlet sensor correspond to a visible increase in the cell voltage. Flow of liquid droplets through this sensor is evidenced by regular impedance peaks. Conversely, and as predicted with water mass balance taking into account water formation and partial transfer to the anode by diffusion, significant amounts of liquid water are present near the outlet, because of water formation along the channel, from the inlet to the outlet. The signal emitted by the sensor located near the cell inlet, with an impedance near 560 kΩ, reveals the presence of dry gas, as expected. 9 shows the TEM image of the nanoparticles.Īn example of cell operation is shown in Fig. Wires of copper and silver having diameter of 1 mm were used and the efficiency regarding the nanofluid synthesis was optimal when T on < T off. The parameters of the process for the synthesis of Ag-Cu composites were proceeded. The metallic particles were constantly stirred by magnetically so that the metallic particles become homogeneously distributed in the dielectric fluid. As the arc discharge continued, the metallic particles got sputtered onto the surface of electrodes and ultimately the electrodes became isolated for the off duration until it followed the next cycle of discharge. The distance between the two electrodes was adjusted to about 30 μm. The two electrodes were adjusted by automatic servo system that made necessary modifications in the distance between the two electrodes for producing an arc discharge at both electrodes tips immersed in the dielectric medium. Cathode and anode of silver and copper of high purity were prepared and immersed in deionized distilled water or in ethyl alcohol (95%).
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