Estudi de la degradació de materials de canvi de fase d’origen vegetal per a la millora de la eficiència energètica en sistemes actius

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2019, Tutores Ana Inés Fernández Renna, Camila Barreneche GuerisoliNowadays, sustainability is one of the most important fields of research due to the importance of making a profitable use of the planet resources. In many fields are working to develop new ways to improve energy efficiency. This is the case of development in phase change materials, a type of chemical substances which contribute to a better efficiency of the thermal energy storage in systems like buildings or refrigerate compartments. There are different materials that can be used as phase change materials, but bio-based materials are very interesting to overcome those made by fossil fuel, for their sustainable characteristics. However, bio-based PCM commercially distributed have been not investigated in deep and due to the lack of investigation on them, these phase change materials implementation in actual buildings is low. One of the principle problems of these materials is the lack of information about their degradation towards daily thermal conditions in a real building. This work focuses in the study of degradation of two fatty acids used as PCM, capric acid and myristic acid, in order to evaluate if their structure or their thermo-physical properties change after two different types of thermal treatments which try to reproduce the daily conditions of a building. Some similar investigations have been previously done on fatty acids degradation, but they focused characterization on infrared spectroscopy, not being able to determinate a structural change on the fatty acids molecules. In this work, further characterization is done, such as DSC and TGA to analyse thermo-physical properties, rheometry to determinate changes in viscosity, and gas chromatography with mass spectrometer detector to obtain better results in structural characterization

Pattern formation and optimization in army ant raids

Army ant colonies display complex foraging raid patterns involving thousands of individuals communicating through chemical trails. In this paper we explore, by means of a simple search algorithm, the properties of these trails in order to test the hypothesis that their structure reflects an optimized mechanism for exploring and exploiting food resources. The raid patterns of three army ant species, {em Eciton hamatum}, {em Eciton burchelli} and {em Eciton rapax}, are analysed. The respective diets of these species involve large but rare, small but common, and a combination of large but rare and small but common, food sources. Using a model proposed by Deneubourg and collaborators, we simulate the formation of raid patterns in response to different food distributions. Our results indicate that the empirically observed raid patterns maximise return on investment, that is, the amount of food brought back to the nest per unit of energy expended, for each of the diets. Moreover, the values of the parameters that characterise the three optimal pattern-generating mechanisms are strikingly similar. Therefore the same behavioural rules at the individual level can produce optimal colony-level patterns. The evolutionary implications of these findings are discussed.Postprint (published version

Mitjanit a la Platja d'Or. El jutge Bertrán de Quintana i els assassinats de Sitges durant la Guerra Civil

A l’agost de 1937 el jutge Bertran de Quintana arribava a Sitges amb una missió: fer justícia pels assassinats ocorreguts en esclatar la guerra civil. La seva investigació va resultar incòmoda per tothom. D’una banda, desarticulava el discurs de la propaganda franquista sobre la manca de justícia a la República; de l’altra, les forces antifeixistes veien com els seus militants eren empresonats i portats davant dels tribunals. El Sumari especial 168-C sobre el cementiri clandestí de Sitges, a través de més d’una seixantena de declaracions dels veïns i veïnes de la vila, no només descobreix una realitat marcada per la violència política a la rereguarda republicana de l’estiu de 1936, sinó que s’emmarca en un moment de la guerra en el qual el significat de la revolució es va intentar posar en qüestió per part de les institucions republicanes

Numerical analysis of heat pumps models: comparative study between equation-fit and refrigerant cycle based models

An equation-fit (EF) and a refrigerant cycle (RC) based heat pump models have been implemented, validated, analyzed and compared to each other under steady state conditions for a brine to water heat pump. Models validations have been provided through comparisons against experimental data obtained at ISFH. The advantages and disadvantages of the both models have been identified. This work provides significant inputs regarding the selection of a specific model depending on the needs. Analysis of mass flow rates and calculations far from typical catalogue data (non-standard conditions) are provided. The main conclusions can be summarized as: i) the EF model is recommended when the boundary conditions for the estimation and prediction modes are the same and when non-standard conditions are considered; ii) the RC model is the chosen alternative when the mass flow rates are modified from the estimation to the prediction mode.Peer ReviewedPostprint (published version

HPC-enabling technologies for high-fidelity combustion simulations

With the increase in computational power in the last decade and the forthcoming Exascale supercomputers, a new horizon in computational modelling and simulation is envisioned in combustion science. Considering the multiscale and multiphysics characteristics of turbulent reacting flows, combustion simulations are considered as one of the most computationally demanding applications running on cutting-edge supercomputers. Exascale computing opens new frontiers for the simulation of combustion systems as more realistic conditions can be achieved with high-fidelity methods. However, an efficient use of these computing architectures requires methodologies that can exploit all levels of parallelism. The efficient utilization of the next generation of supercomputers needs to be considered from a global perspective, that is, involving physical modelling and numerical methods with methodologies based on High-Performance Computing (HPC) and hardware architectures. This review introduces recent developments in numerical methods for large-eddy simulations (LES) and direct-numerical simulations (DNS) to simulate combustion systems, with focus on the computational performance and algorithmic capabilities. Due to the broad scope, a first section is devoted to describe the fundamentals of turbulent combustion, which is followed by a general description of state-of-the-art computational strategies for solving these problems. These applications require advanced HPC approaches to exploit modern supercomputers, which is addressed in the third section. The increasing complexity of new computing architectures, with tightly coupled CPUs and GPUs, as well as high levels of parallelism, requires new parallel models and algorithms exposing the required level of concurrency. Advances in terms of dynamic load balancing, vectorization, GPU acceleration and mesh adaptation have permitted to achieve highly-efficient combustion simulations with data-driven methods in HPC environments. Therefore, dedicated sections covering the use of high-order methods for reacting flows, integration of detailed chemistry and two-phase flows are addressed. Final remarks and directions of future work are given at the end. }The research leading to these results has received funding from the European Union’s Horizon 2020 Programme under the CoEC project, grant agreement No. 952181 and the CoE RAISE project grant agreement no. 951733.Peer ReviewedPostprint (published version

Objetivos formativos y estrategias docentes para el primer curso de las ingenierías informáticas

En este artículo se presentan una propuesta de objetivos formativos para el primer curso de las titulaciones universitarias en informática y un conjunto de estrategias docentes para conseguirlos. Los objetivos formativos se han clasificado en tres grupos: conocimientos, procedimientos y actitudes, valores y normas. El artículo se centra en los objetivos relativos a procedimientos, y en particular en aquéllos que pueden comenzar a conseguirse ya desde el primer curso, describiendo algunas estrategias docentes que permiten conseguirlos

Cómo diseñar un Grado en Informática

Este artículo pretende ser una guía con recomendaciones prácticas para el diseño de un plan de estudio de Grado con orientación profesional. Se describe una metodología para diseñar el plan de estudio a partir de una lista de competencias profesionales y otra de restricciones y criterios fijados por el centro. Al final de este proceso, se obtiene un plan de estudio donde todas las asignaturas están especificadas mediante una lista de objetivos y el número de créditos ECTS asociado a cada uno de dichos objetivos