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Hybrid Renewable Energy Systems have been considered as a suitable way to supply electricity. The hybrid energy (Solar-Wind-Storage-hydrogen-diesel) is increasingly used in various applications, especially at isolated sites. This study proposes the optimization and analysis of a stand-alone photovoltaic/battery/fuel cell/electrolyzer/hydrogen hybrid system (HS) to find out the optimal sizes and costs. In the first step, SAM software was used to estimate the global solar irradiance (GHI) for the studied area and to select the best PV, battery and fuel cell components. MATLAB software was handled to predict the power output of the renewable source (PV system) using an Artificial Neural Network (ANN) model. Then, simulation, optimization and techno-economic analysis were carried out in the second step with HomerPro software. Four proposed configurations are optimized in this work and different comparisons have been made regarding the found results. The results of the cost optimization were found to be 50861.21 $ and 0.95657 $ for NCP and COE, respectively. Moreover, the same HS configurations are simulated and optimized under Moroccan climate. • Hybrid Renewable Energy Systems is a suitable way to supply electricity. • A stand-alone photovoltaic/battery/fuel cell/electrolyzer/hydrogen hybrid system. • SAM software was used to estimate the global solar irradiance. • MATLAB was handled using an Artificial Neural Network model. • Optimization and techno-economic analysis with HomerPro software. [ABSTRACT FROM AUTHOR]

In this paper, the main objective is the simulation of the electric supply for homes in remote areas located in Morocco (Oujda and Ouarzazate), Spain (Granada), and Algeria (Bechar). This simulation study is divided into two ideas, the first one is to optimize the hybrid system under a varied number of houses and the second part is to fix it in chosen values. This work relied on the particle swarm optimization (PSO) method to optimize and analyze the proposed stand-alone photovoltaic/wind/diesel/battery hybrid system. MATLAB software is used to run the simulations and to carry out the optimal solutions of the optimized system using a developed PSO algorithm. The PSO approach contains five principal operator axes, which are problem definition, PSO initial parameters, initialization, PSO main loop, and then run of the algorithm. Optimizing the system component sizes and reaching the minimum cost of energy (COE) were the function objectives of this optimization study. Moreover, calculation of the hydrogen production from the generated energy by PV and wind systems is performed. [ABSTRACT FROM AUTHOR]

In the eighties of 20th century, Vergil was interpreted from a precise and particular approach inspired by Nietzsche. This new vision could be categorized, basically, as the idea of death (Broch), the sickness of poetry (García Calvo), the commemoration (remembrance) of the bimillennium of his death (Colinas), his poetic rereading from a new aesthetics (Borges and Bernhard), the boom of verse translation (Fontán Barreiro) and, finally, the remarkable picto-rial rereading of his Eneida (Carlos Franco). Therefore, this essay tries to give an account of a specific decade in Vergil's historical reception. [ABSTRACT FROM AUTHOR]

In Spain, the COVID-19 pandemic has impacted the various regions of the country differently. The availability of reliable and up-to-date information has proved to be fundamental for the management of this health crisis. However, especially during the first wave of the pandemic (February–August 2020), the disparity in the recording criteria and in the timing of providing these figures to the central government created controversy and confusion regarding the real dimension of the pandemic. It is therefore necessary to have objective and homogeneous criteria at the national level to guide health managers in the correct recording and evaluation of the magnitude of the pandemic. Within this context, we propose using Benford's Law as an auditing tool to monitor the reliability of the number of daily COVID-related deaths to identify possible deviations from the expected trend. [ABSTRACT FROM AUTHOR]

This paper describes the configuration, modeling, and control of a fuel cell (FC)-battery-powered hybrid system for the Metro Centro tramway in Seville, Spain. The proposed hybrid system presents a polymer electrolyte membrane FC as the primary energy source and a nickel-metal hydride cell battery as the secondary energy source, which supplements the output of the FC during tramway acceleration or whenever else needed and cruise and for energy recovery during braking. The tramway presents a traction system which is composed of four traction induction motor drives. The hybrid system also supplies the power for the auxiliary services. The power conditioning system is composed of two converters: 1) a boost-type unidirectional dc/dc converter for the FC and 2) a boost-type bidirectional dc/dc converter for the battery. The energy management system (EMS) of the hybrid tramway determines the reference signals for the electric motor drives, FC, and power converters in order to regulate accurately the power from the two electrical sources. EMS also determines the reference signal for energy dissipation in braking chopper when required during regenerative braking. In this paper, the proposed hybrid system is evaluated for the real driving cycle of the tramway. The results demonstrate the hybrid system capability to meet appropriate driving cycle. [ABSTRACT FROM PUBLISHER]

Seasonality is a widely recognised and accredited phenomenon known to cause an imbalance in tourism activity throughout the year, prompting tourist destinations, both public and private, to consider how best to plan the use of their resources. One way of mitigating the economic imbalances that seasonality can cause is to find strategies for seasonal adjustment, such as travel programmes aimed at the elderly. This paper analyses the seasonality of tourism activity in some EU countries, and in particular in Spain. Different indicators are used to compare the results and carry out a sensitivity analysis. The study then focuses on tourism programmes for the elderly in Spain to see whether this type of programme helps to alleviate the seasonality of tourism activity. To corroborate this, an econometric model is specified and estimated, which enables the scope of these programmes to be compared. [ABSTRACT FROM AUTHOR]

The seasonality of births is an issue that has received much attention in the literature. Empirical evidence has revealed that annual birth distributions have evolved from environmentally-regulated fertility patterns to models that are dominated by socio-cultural factors. This study expands upon this literature by examining the weekly distribution of births and its evolution over the past decades. Using the micro-data of the municipal register files of the Valencian Community (n=3,674,110), we empirically reveal that the current organization of work schedules in the healthcare sector impacts the weekly distribution of births, resulting in the hegemonic position of the medical profession. This has been confirmed by the change in the distribution of births, by days of the week, since the mid-20th century until the present date. [ABSTRACT FROM AUTHOR]