Polytechnic University of Valencia

About: Polytechnic University of Valencia is a education organization based out in Valencia, Spain. It is known for research contribution in the topics: Catalysis & Population. The organization has 16282 authors who have published 40162 publications receiving 850234 citations.

Wideband double-fed planar monopole antennas

Abstract: Planar monopole antennas with multiple feed points are proposed to improve pattern and impedance bandwidth. A square planar monopole antenna including two feed points and a bevelled variant are designed. These antennas exhibit an excellent performance compared to existing planar monopoles.

Active sites on graphene-based materials as metal-free catalysts

Abstract: Graphenes and related materials have attracted growing interest as metal-free catalysts The present review is focused on describing the active sites that have been proposed to be responsible for the catalytic activity observed for such systems It will be shown that diverse defects and chemical functionalities on the graphene layers can catalyze reactions, including oxygenated functional groups, carbon vacancies and holes, edge effects, and the presence of dopant elements Besides discrete active sites, the catalytic activity arising from the collective properties of graphenes as materials by adsorbing substrates and reagents and activating them by charge transfer is also commented The review has an introductory general section summarizing the general methodologies that have been used to support the proposed structure of the active sites, including theoretical calculations, comparison of the catalytic activity of graphene samples with different compositions, the use of organic molecules as models of the active centers, and selective masking of functional groups The review is concluded with our view on future developments in the field