Programación de un software para el prediseño del sistema de potencia de un satélite de órbita baja "Satellite Power simulation"

Programación de un software para el prediseño del sistema de potencia de un satélite de órbita baja. satellite power simulato

Diseño de un programa para disminuir los síntomas del burnout en los profesionales sanitarios

En los últimos años y sobre todo en los profesionales dedicados al ámbito asistencial, como es el caso del personal sanitario, se ha incrementado el número de casos de profesionales que padecen el síndrome de Burnout o síndrome de estar quemado, debido entre otras cosas al estrés que genera el contacto permanente con los pacientes. En este trabajo se describen los principales factores y variables que generan el síndrome de burnout, y que posteriormente tendremos en cuenta para el diseño del programa, con la finalidad de intentar disminuir los síntomas generadores de éste y crear un perfil específico que atienda individualmente al profesional sanitario

Pantograph-Catenary Dynamic Models and their Implementation in Hardware-in-the-Loop Tests

Tesis por compendio[ES] Existe una extensa red de líneas ferroviarias electrificadas en todo el mundo. La mayoría de ellas utilizan líneas aéreas de contacto o catenarias para suministrar electricidad a los trenes. Las catenarias son estructuras de cables ubicadas sobre las vías ferroviarias, diseñadas para ser contactadas por los pantógrafos que se encuentran sobre la parte superior de los trenes. El correcto funcionamiento del sistema requiere un alto nivel de exigencia, especialmente a alta velocidad, cuando la continuidad del contacto se ve comprometida. La herramienta más empleada el sistema pantógrafo-catenaria es el uso de simulaciones numéricas. En particular, el Método de los Elementos Finitos (MEF) es la técnica más extendida para modelar y simular la interacción dinámica del pantógrafo con la catenaria. Después de la etapa de simulación, el pantógrafo y la catenaria tienen que ser testados mediante ensayos experimentales en vía. Sin embargo, existe una alternativa que puede reemplazar esos ensayos con una reducción significativa de costes. Dicha alternativa, llamada Hardware In the Loop (HIL), permite testar pantógrafos en el laboratorio mediante un banco de ensayos que emula la interacción con una catenaria virtual. Diferentes grupos de investigación han implementado HIL; sin embargo, en todos los intentos se han adoptado soluciones de compromiso, lo que demuestra el reto que supone la aplicación de HIL. Esta Tesis pretende avanzar en el campo de ensayos HIL, impulsando las capacidades de la técnica y solventando algunas de las limitaciones encontradas en la literatura. Para ello se proponen dos tipos diferentes de modelos de catenaria para su uso en ensayos HIL. El primero es un modelo analítico basado en un cable tensado con perfil geométrico periódico que proporciona la solución estacionaria del sistema. Este enfoque reduce la complejidad de la catenaria, pero mantiene las principales características que intervienen en la dinámica. El modelo ha demostrado ser útil para explicar el comportamiento fundamental de la catenaria, ayudando a comprender el fenómeno de interferencia entre dos pantógrafos. Este modelo analítico es adecuado para HIL debido a su bajo coste computacional. En el presente trabajo se propone un algoritmo iterativo para utilizar el modelo analítico en HIL. El hecho de que el modelo sea periódico permite la aplicación de una estrategia específica para compensar el retraso del lazo de control. Esta estrategia tiene un excelente rendimiento y precisión, validados al comparar ensayos HIL con simulaciones. La validación se realiza con un peso en el lugar del pantógrafo para eliminar las potenciales diferencias en el modelo. Si bien la precisión alcanzada es buena, el modelo analítico de catenaria carece de fidelidad, lo que ha motivado el desarrollo del siguiente modelo. El segundo modelo de catenaria para ensayos HIL es el Modelo Periódico de Elementos Finitos (MPEF), discretizado con el MEF para evitar adicionales simplificaciones topológicas y estructurales. En la formulación se incluye la condición de periodicidad y la dinámica se resuelve mediante análisis en frecuencia. Además, las no linealidades de la catenaria se consideran en la formulación. Un algoritmo iterativo, similar al utilizado para los ensayos HIL con catenaria analítica, es usado para realizar ensayos HIL con catenarias MPEF. La estrategia anterior de utilización de un peso se emplea para validar el sistema de ensayos, resultando tener una gran precisión. Los resultados son gratificantes debido a la sofisticación del modelo de catenaria, la precisión de los ensayos y la cancelación del retraso. Los ensayos realizados simulan la respuesta de catenarias realistas con la hipótesis simplificativa de periodicidad. Son adecuados para la dinámica de catenarias de vanos iguales en la zona central de cada cantón, sin embargo es necesario seguir realizando esfuerzos para eliminar la condición de periodicidad sin comprometer la precisión de los resultados.[CA] Existeix una extensa xarxa de línies ferroviàries electrificades a tot el món. La majoria d'elles utilitzen Línies Aèries de Contacte o catenàries per a subministrar electricitat als trens. Les catenàries són estructures de cables situades sobre les vies ferroviàries, dissenyades per a ser contactades pels pantògrafs que es troben sobre la part superior de la locomotora. El correcte funcionament del sistema requereix un alt nivell d'exigència, especialment a alta velocitat, quan la continuïtat del contacte es veu compromesa. L'eina majoritària per el sistema pantògraf-catenària és l'ús de simulacions numèriques. En particular, el Mètode dels Elements Finits (MEF) és la tècnica més usada per a modelar i simular la interacció dinàmica del pantògraf amb la catenària. Aquest mètode permet modelar catenàries. Després de l'etapa de simulació, el pantògraf i les catenàries han de ser testats en assajos experimentals en via. No obstant això, existeix una alternativa que pot reemplaçar eixos assajos amb una reducció significativa de costos. Aquesta alternativa, anomenada Hardware in the Loop (HIL), permet testar pantògrafs en el laboratori amb un banc d'assajos que emula la interacció amb una catenària virtual. Diferents grups d'investigació han implementat HIL; no obstant això, en tots els intents s'han adoptat solucions de compromís, la qual cosa demostra el repte que suposa l'aplicació de HIL. Aquesta Tesi pretén avançar en el camp dels assajos HIL, impulsant les capacitats de la tècnica i solucionant algunes de les limitacions trobades en la literatura. Aquesta Tesi proposa dos tipus diferents de models de catenària per al seu ús en assajos HIL. El primer és un model analític basat en un cable tens amb perfil geomètric periòdic que proporciona la solució estacionària del sistema. Aquest model redueix la complexitat de la catenària, però manté les principals característiques que intervenen en la dinàmica. El model ha demostrat ser útil per a explicar la dinàmica fonamental de la catenària, ajudant a comprendre el fenomen d'interferència entre dos pantògrafs. Aquest model analític és adequat per a realitzar assajos HIL a causa del seu baix cost computacional. Aquest treball proposa un algoritme iteratiu per a utilitzar el model analític en assajos HIL de pantògrafs. El fet que el model siga periòdic permet l'aplicació d'una estratègia específica per a compensar el retard del llaç de control. Aquesta estratègia té un excel·lent rendiment i precisió, validats en comparar assajos HIL amb simulacions numèriques. La validació es realitza amb una massa en el lloc del pantògraf per a eliminar les potencials diferències en el model. Si bé la precisió aconseguida és bona, el model analític de catenària manca de fidelitat, la qual cosa ha motivat el desenvolupament d'un model periòdic més avançat. El segon model de catenària per a assajos HIL és el Model Periòdic d'Elements Finits MPEF, discretitzat amb el MEF per a evitar simplificacions topològiques i estructurals addicionals. El model inclou la condició de periodicitat i la dinàmica es resol mitjançant anàlisi en freqüència. A més, les no linealitats de la catenària es consideren en la formulació. Un algoritme iteratiu, similar a l'utilitzat per als assajos HIL amb catenària analítica, és usat per a realitzar assajos HIL amb catenàries MPEF. L'estratègia anterior d'utilització d'una massa s'empra per a validar el sistema d'assajos, resultant tindre una gran precisió. Els resultats són gratificants a causa de la sofisticació del model de catenària, la precisió dels assajos i la cancel·lació del retard. Els assajos realitzats simulen la resposta de catenàries realistes amb la hipòtesi simplificativa de periodicitat. Són adequats per a la dinàmica de catenàries de vans iguals en la zona central dels seccionaments, no obstant això és necessari continuar fent esforços per a eliminar la condició de periodicitat sense comprometre la precisió dels res[EN] There is an extensive network of electrified railway lines over the world. Most of them use overhead contact lines or catenaries to provide the trains with electrical power. Catenaries consist of electrified wires placed over the rail track, designed to contact the pantograph placed on the roof of the train. The proper operation of the system is very demanding, especially at high speed, when the continuity of the contact is compromised. The most predominant tool for studying and designing the pantograph-catenary system is the use of numerical simulations. Notably, the Finite Element Method (FEM) is the most popular technique for modelling and simulating the dynamic interaction of the pantograph and the catenary. This method allows modelling catenaries with outstanding fidelity and without any loss of generality. After the simulation stage, the pantograph and the catenaries have to be assessed by in-line experimental tests. However, there is an alternative that can replace those tests with a significant reduction in costs. The alternative method, called Hardware In the Loop (HIL), allows testing pantographs in the laboratory with a test rig that emulates the interaction with a virtual catenary. Different research groups have implemented HIL; however, in every attempt, a compromise solution has been adopted, demonstrating the challenging nature of HIL. This Thesis aims to advance in the field of HIL tests, pushing forward the capabilities of the technique and solving some of the limitations found in the literature. This Thesis proposes two different kinds of catenary models for their use in HIL tests. The first is an analytical model based on a string of periodic geometric profile that accounts for the steady state. It reduces the complexity of the catenary but keeps the main features involved in the dynamic. The model has proven useful in explaining the fundamental dynamics of the catenary, helping understand the interference between two pantographs. This analytical model is suitable for HIL because of its low computational cost. An iterative algorithm is proposed to use the analytical model in HIL. The fact that the model is periodic permits a specific strategy to compensate the control loop delay. This strategy has excellent performance and accuracy, validated by comparing HIL tests with numerical simulations and getting an agreement. This agreement will not be possible if the pantograph model of the simulations is inaccurate. Therefore, the validation is carried out with a weight or mass model in place of the pantograph to eliminate potential differences. Even though the precision achieved is good, the analytical catenary model lacks fidelity, which has motivated the development of a more advanced periodic model. The second catenary model for HIL tests is the Periodic Finite Element Model (PFEM), discretised with FEM to avoid further topological and structural simplifications. The model includes the periodicity condition, and the dynamics are solved by frequency analysis. Furthermore, the catenary non-linearities are considered in the formulation. An iterative algorithm, similar to the one used for the HIL tests with the analytical catenary, is used to realise HIL tests with PFEM catenaries. The previous strategy with a mass model is used to validate the test, confirming great precision. The results are gratifying due to the sophistication of the model, the accuracy of the tests and the cancellation of the delay. The tests simulate the response of realistic catenaries with the simplifying periodicity hypothesis. They are adequate for the dynamic of equal-span catenary at the central zone of every section, but future efforts have to be made to get rid of the periodicity condition while keeping the accuracy of the results.The authors would like to acknowledge the financial support received from the State Research Agency of the Spanish Science and Innovation Ministry (PID2020- 113458RB-I00) and from the Valencian Regional Government (PROMETEO/2021/046) (PROMETEO/2016/007) and the Spanish Ministry of Economy, Industry and Competitiveness (TRA2017-84736-R), also the funds received jointly from the Regional Government of Valencia and the Euro- pean Social Fund, under Grant APOSTD/2019/205Gil Romero, J. (2022). Pantograph-Catenary Dynamic Models and their Implementation in Hardware-in-the-Loop Tests [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/191501Compendi

Measures to promote renewable energy for electricity generation in Algeria

Algeria has enormous renewable energy potential. However, fossil fuels remain the main electricity generation source, and the country is the third largest CO2 emitter in Africa. Algeria is also particularly vulnerable to climate change. Therefore, a set of actions related to energy, forests, industry and waste sectors have been programmed, over the period 2015–2030, and the government action program has given priority to promote renewable energy. In this sense, Algeria is committed to significantly promote investment in renewable energy, during the period 2020–2030. Thus by 2030, renewable electricity production capacity will achieve 22,000 MW, representing 27% of total electricity generation. This paper analyzes the electricity generation measures implemented in Algeria to reach the required energy mix, the legislative framework, financial aid, the feed-in tariff system, the tax incentives, and the tender and auctions undertaken. The analyses reveal that, although the electricity price premium policy has not been revoked, the newly enacted tender scheme is designed to become the standard procedure for launching renewable energy projects in Algeria in the coming years

Residential electricity consumption and economic growth in Algeria

Within the framework of the COP21 (Conference of the Parties) agreement, Algeria submitted its Intended Nationally Determined Contribution pledging to reduce carbon emissions by at least 7% by 2030. However, it will be a difficult task to reach this target as total final energy consumption has increased 32% from 2010 to 2014, with the major energy increases being related to electricity use in the residential sector. In this context, the relationship between residential electricity consumption and income is analyzed for Algeria in the period 1970–2013, by estimating a residential electricity consumption per capita demand function which depends on GDP per capita, its squared and cubed terms, the electricity prices, and the goods and services imports. An extended Autoregressive Distributed Lag model (ARDL) was adopted to consider the different growth patterns registered in the evolution of GDP. The estimate results show that the relationships between electricity use and GDP (in per capita terms) present an inverted N-shape, with the second turning point having been reached. Therefore, promoting growth in Algeria could be convenient to reduce the electricity consumption, as a higher income level may allow the use of more efficient appliances. Additionally, renewable energies may be adequate to increase the electricity production in order to cover the increasing residential demand.Junta de Andalucía proyecto SEJ-132Ministerio de Economía y Competitividad de España, Cátedra de Economía de la Energía y del Medio Ambiente (Cátedra de Energía y Economía Ambiental) ECO2014-56399-

The relationships between total, electricity and biofuels residential energy consumption and income in Latin America and the Caribbean Countries

Controlling residential energy consumption in Latino America and the Caribbean countries is crucial to reduce CO2 emissions, as it has an important energy-saving potential, and its environmental controls are difficult to displace offshore. The aim of this study is to analyze the relationships between residential energy consumption and income for 22 Latin America and the Caribbean countries in the period 1990-2013. For this purpose, residential energy environmental Kuznets curves (EKC) are estimated by taking into account the heterogeneity among the countries by including two control variables: one representing the possible effect of urbanization on residential energy use and the second representing the possible effect of petrol production. The EKC are estimated for total residential energy consumption, for residential electricity consumption and for biofuels and waste energy consumption. The elasticities of total, electricity and biofuels residential energy consumption with respect to income are calculated for each year and country, analyzing the different behavior between countries. Obtained results show that the EKC hypothesis is confirmed for the residential sector when the biofuels energy consumption is considered. Moreover, the results also show that the turning point has been reached in some countries. Nevertheless, the EKC is not confirmed when electricity or total residential energy consumption is considered. Thus, for total residential energy consumption, the elasticity is always positive, growing also as the income does. For electricity energy consumption, the elasticity is also always positive, since although the elasticity decreases until a threshold, from an per capita income value it begins to grow

Coupled electric and magnetic dipole formulation for planar arrays of dipolar particles: metasurfaces with various electric and/or magnetic meta-atoms per unit cell

The optical properties of infinite planar array of scattering particles, metasurfaces and metagratings, are attracting special attention lately for their rich phenomenology, including both plasmonic and high-refractive-index dielectric meta-atoms with a variety of electric and magnetic resonant responses. Herein we derive a coupled electric and magnetic dipole (CEMD) analytical formulation to describe the reflection and transmission of such periodic arrays, including specular and diffractive orders, valid in the spectral regimes where only dipolar multipoles are needed. Electric and/or magnetic dipoles with all three orientations arising in turn from a single or various meta-atoms per unit cell are considered. The 2D lattice Green function is rewritten in terms of a 1D (chain) version that fully converges and can be easily calculated. Modes emerging as poles of such lattice Green function can be extracted. This formulation can be applied to investigate a wealth of plasmonic, all-dielectric, and hybrid metasurfaces/metagratings of interest throughout the electromagnetic spectrum.Comment: 8 pages, 4 figure

Organización eclesiástca y vida rural en la temprana edad moderna: la Tierra de Montánchez, dominio de la Orden de Santiago

-

Tourism and hospitality sector electricity use: evidences from 12 EU countries

At the Paris Conference of the Parties (COP21) in 2015, 195 countries agreed to strengthen the global response to the threat of climate change. Along this line, the EU is committed to a 40% reduction in their domestic greenhouse gas emissions by 2030. This new target represents a significant progression beyond its existing 20% emission reduction commitment by 2020. Thus, greater efforts will be needed affecting all productive sectors in order to reduce CO2 emissions and energy consumption. In order to reach this ambitious target, new measures affecting all economic sectors would be needed. This paper focuses on the tourism sector. This aim of this study is to investigate the relationships between tourist overnight stays and the hospitality sector electricity consumption. These relationships are studied for 12 EU countries during the period 2005-2012, accordingly with the available data. With this aim, econometric panel data techniques are used in order to estimate an electricity consumption function for the hospitality sector which depends on tourism, income, price and climate variables. The Environmental Kuznets Curve hypothesis is also tested. An Energy-tourism Kuznets Curve would show that increasing earnings from tourism will bring about reduced electricity consumption from a threshold point, which could be related to the fact that more earnings could imply undertaking more energy efficiency measures