University of Patras

About: University of Patras is a education organization based out in Pátrai, Greece. It is known for research contribution in the topics: Population & Catalysis. The organization has 13372 authors who have published 31263 publications receiving 677159 citations. The organization is also known as: Panepistímio Patrón.

Diol-type ligands as central ‘players’ in the chemistry of high-spin molecules and single-molecule magnets

Abstract: The combination of diol-type ligands with paramagnetic transition metal ions has led to the isolation of a host of new homometallic and heterometallic clusters, high-spin molecules and single molecule magnets ranging in nuclearity from two to forty four and with spin ground states as large as S = 61/2. The ligands, whose cluster coordination chemistry is discussed in this article, are 1,3-propanediol and its derivatives, diethanolamine and its derivatives, pyridine-2,6-dimethanol and the gem-diol form of di-2-pyridyl ketone. The structural diversity of the complexes stems from the ability of the ligands to adopt a variety of bridging coordination modes depending on the positions of the two hydroxyl groups in the molecule, the presence/absence of extra donor groups and on the reaction conditions. Examples of ‘true’ reactivity chemistry involving clusters of diol-type ligands are also given. The activation of pyridine-2,6-dimethanol and di-2-pyridyl ketone by 3d-metal centres towards further reactions seems to be an emergent area of synthetic chemistry.

Energy, cost and LCA results of PV and hybrid PV/T solar systems

Abstract: Hybrid photovoltaic/thermal (PV/T) solar systems provide a simultaneous conversion of solar radiation into electricity and heat. In these devices, the PV modules are mounted together with heat recovery units, by which a circulating fluid allows one to cool them down during their operation. An extensive study on water-cooled PV/T solar systems has been conducted at the University of Patras, where hybrid prototypes have been experimentally studied. In this paper the electrical and thermal efficiencies are given and the annual energy output under the weather conditions of Patras is calculated for horizontal and tilted building roof installation. In addition, the costs of all system parts are included and the cost payback time is estimated. Finally, the methodology of life cycle assessment (LCA) has been applied to perform an energy and environmental assessment of the analysed system. The goal of this study, carried out at the University of Rome ‘La Sapienza’ by means of SimaPro 5·1 software, was to verify the benefits of heat recovery. The concepts and results of this work on energy performance, economic aspects and LCA results of modified PV and water-cooled PV/T solar systems, give a clear idea of their application advantages. From the results, the most important conclusion is that PV/T systems are cost effective and of better environmental impact compared with standard PV modules. Copyright © 2005 John Wiley & Sons, Ltd.