Seawater zinc/polypyrrole-air cell possessing multifunctional charge-discharge characteristics

An environmentally friendly cell using polypyrrole-air regenerative cathode and zinc as anode is investigated in the 3% sodium chloride solution. The cell can operate in different charge and discharge mode. Polypyrrole can be reoxidized (doped) with chloride anions either by using dissolved oxygen or by an external power supply, e.g., small photovoltaic cell. In that way, after discharge, capacity retaining can be achieved by using seawater as the electrolyte. During low discharge rate, the delicate balance between solid state diffusion-controlled dedoping and chemical oxidation of polypyrrole produced by hydrogen peroxide is achieved, generating stable voltage plateau. The cell is proposed to operate as a power supply for different sensor devices in two modes. In the low discharge mode (10-20 mA g(-1)), it can be used for data acquisition, and at the fast discharge mode (up to 2 A g(-1)) for collecting data transmission

Electroweak parameters of the z0 resonance and the standard model

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Exploring the possibilities of laser interference patterning for the rapid fabrication of periodic arrays on macroscopic areas

Surface patterning engineering techniques are essential to fabricate advanced topographies that can be use to modulate macroscopic properties on different materials. Particularly, Laser Interference methods enable fabrication of repetitive periodic arrays and microstructures by irradiation of the sample surface with coherent beams of light. Depending on the used laser source, different methods have emerged in the last years including Laser Interference Lithography and Direct Laser Interference Patterning. A detailed description of these techniques is presented in this chapter. In addition, several examples including fabrication of micro and sub-micrometer patterns on photoresists, conducting polymers and carbon nanotubes are described

Theoretical Study of Oxygen Reduction Reaction Catalysts: From Pt to Non-precious Metal Catalysts

Fuel cells are regarded as one of the most promising candidates for stationary and mobile power generation due to their high energy yield and low environmental impact of hydrogen oxidation. The oxygen reduction reaction (ORR) at cathode is a very complex process and plays a crucial role during operation of the PEM fuel cells. However, its mechanism and the nature of intermediates involved remain vague. This chapter focuses on the recent theoretical modeling studies of ORR catalysts for PEMFC. Recent theoretical investigations on oxygen reduction electrocatalysts, such as Pt-based catalysts, non-Pt metal catalysts (Pd, Ir, CuCl), and non-precious metal catalysts (transitional metal macrocyclic complexes, conductive polymer materials, and carbon-based materials), are reviewed. The oxygen reduction mechanisms catalyzed by these catalysts are discussed based on the results. ? Springer-Verlag London 2013.EI0339-373