Parameter characterization of HTPEMFC using numerical simulation and genetic algorithms

This paper develops a novel approach to the parameterisation of high temperature exchange membrane fuel cells (HTPEMFC) with limited and non-invasive measurements. The proposed method allows an effective identification of electrochemical parameters for three-dimensional fuel cell models by combining computational simulation tools and genetic algorithms. To avoid each evaluation undertaken by the optimisation method involving a complete computational simulation of the 3D model, a strategy has been designed that, thanks to an iterative process, makes it possible to decouple the fluid dynamic resolution from the electrochemistry one. Two electrochemical models have been incorporated into these tools to describe the behaviour of the catalyst layer, Butler-Volmer and spherical aggregate. For each one, a case study has been carried out to validate the results by comparing them with empirical data in the first model and with data generated by numerical simulation in the second. Results show that, from a set of measured operating conditions, it is possible to identify a unique set of electrochemical parameters that fits the 3D model to the target polarisation curve. The extension of this framework can be used to systematically estimate any model parameter in order to reduce the uncertainty in 3D simulation predictions. © 2021 The Author(s

Macroscopic heat release in a molecular solar thermal energy storage system

The development of solar energy can potentially meet the growing requirements for a global energy system beyond fossil fuels, but necessitates new scalable technologies for solar energy storage. One approach is the development of energy storage systems based on molecular photoswitches, so-called molecular solar thermal energy storage (MOST). Here we present a novel norbornadiene derivative for this purpose, with a good solar spectral match, high robustness and an energy density of 0.4 MJ kg -1 . By the use of heterogeneous catalyst cobalt phthalocyanine on a carbon support, we demonstrate a record high macroscopic heat release in a flow system using a fixed bed catalytic reactor, leading to a temperature increase of up to 63.4 °C (83.2 °C measured temperature). Successful outdoor testing shows proof of concept and illustrates that future implementation is feasible. The mechanism of the catalytic back reaction is modelled using density functional theory (DFT) calculations rationalizing the experimental observations

Iglesia parroquial de Santiago, Calahorra (La Rioja): realización de catas para la comprobación de existencia de policromía bajo capas de pintura visible

Durante las obras realizadas en la iglesia de Santiago de Calahorra, en el año 2005 y a la vez que llevábamos a cabo la restauración de las pinturas murales de la capilla de San Martín de esta parroquia, realizamos una serie de catas para comprobar la existencia de otras pinturas murales bajo la pintura visible en esos momentos en diversas zonas de la iglesia. Los resultados quedaron recogidos en un informe escrito y gráfico. Reflejamos en este artículo los más interesantes

Restauración de las pinturas murales de la capilla del Espíritu Santo de la Catedral de Calahorra

Este artículo es en gran parte un extracto del informe final de la restauración de las pinturas murales de la capilla del Espíritu Santo de la catedral de Calahorra,. Pinturas murales que presentaban un pésimo estado hasta el punto de peligrar su conservación y futura existencia, y que gracias al empeño de la Asociación Amigos de la Catedral se han podido salvar y restaurar

Restauración de las pinturas murales de la capilla del Espíritu Santo de la Catedral de Calahorra

Este artículo es en gran parte un extracto del informe final de la restauración de las pinturas murales de la capilla del Espíritu Santo de la catedral de Calahorra,. Pinturas murales que presentaban un pésimo estado hasta el punto de peligrar su conservación y futura existencia, y que gracias al empeño de la Asociación Amigos de la Catedral se han podido salvar y restaurar

Computational exploration of the photoprotective potential of gadusol

Gadusol shows one of the simplest structures among a series of natural UV-absorbing compounds that have been related to the photoprotective and antioxidant functions in aquatic organisms. CASPT2//CASSCF methodology was used to carry out a theoretical study on this basic structure in order to describe the underlying features responsible for the photoprotective capacity of the molecule. The influence of the enol-enolate equilibrium on the photophysical properties was explored. The results confirm that both forms undergo a rapid deactivation, which very efficiently dissipates light energy as heat. This work highlights the potential of molecular-level studies to provide an understanding of natural photoprotective mechanisms and gives support to the future design of structurally related new synthetic sunscreens. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA