152 research outputs found

    A previously unpublished painting by José Risueño m the Church at Torvizcon (Granada)

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    Es escasa la documentación conocida de la obra de José Risueño y tampoco son numerosas sus obras firmadas. En el presente estudio se da a conocer la realización, por parte de Risueño, de un lienzo con destino a la iglesia de Torvizcón y la presencia en esta iglesia de un cuadro firmado por el pintor, aunque de tema aparentemente diferente. Asimismo, se ofrece la fotografía de otro cuadro casi idéntico, en formato y tema, al aquí estudiado, así como noticias sobre la actividad profesional de algunos familiares del artista.Little is known of the work of José Risueño and there are few authenticated paintings. In the present paper a painting designed for the church at Torvizcón is described, as is an authenticated painting in the same church, whose subject is however a different one. We discuss the photograph of another painting which is almost identical in forma! and subject to that described here, and also provide information about the professional activities of members of the painter's family

    Una obra de Alonso de Mena y Escalante el Cristo de la Expiración de Adra (Almería)

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    In this paper we review the historiographical studies, and especially those in Almería, which have dealt with Pedro de Mena y Medrano, a native of Adra (Almería). We provide important documentary evidence to show the relationship of the Mena family with Adra, and then proceed to an analysis of the "Dying Christ" (Cristo de la Expiración) to be found in this town. This image is especially significan! since it is the first clearly documented Crucifixion by Alonso de Mena y Escalante. Together with this Christ fi gure, Alonso de Mena contracted to sculpt a St. Sebastian, and sorne supports for this figure. Unfottunately the St. Sebastian, and sorne supports for this figure. Unfortunately the St. Sebastian has been lost, but it would have enriched the variety of iconographic types created by this sculptor.En este artículo se hace un repaso de la historiografía, y en concreto de la almeriense, que consideraba a Pedro de Mena y Medrano natural de Adra (Almería). Con un importante apoyo documental se explica la relación de los Mena con Adra, pasando después a analizar el Cristo de la Expiración de esta localidad, imagen especialmente significativa por ser el primer Crucificado documentado de Alonso de Mena y Escalante. Junto al Cristo, Alonso de Mena se comprometía a realizar un San Sebastián y unas andas para éste. El San Sebastián, desgraciadamente perdido, vendría a enriquecer la variada creación de tipos iconográficos de este escultor

    Causes of mortality among adults with Down syndrome before and after the COVID-19 pandemic in Spain

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    Background: The life expectancy of people with Down syndrome (DS) is limited by Alzheimer's disease (AD)-related deaths, mainly due to respiratory infections. The emergence of the COVID-19 pandemic could have changed known, past trends in mortality in this population. We analysed the differences in causes of mortality between individuals with DS deceased before and after the onset of the pandemic. Method: This is a cross-sectional study of adults with DS recruited at a tertiary, university outpatient clinic in Madrid, Spain. Demographic and clinical data were retrospectively collected from their medical records, including information on their deaths, if any. Results: Five hundred seventy-two adults were included in the study, and 67 (11.7%) died. The main cause of death was respiratory infections, which occurred in 36 participants [9 (45.0%) before, and 27 (58.7%) after the appearance of COVID-19]. No significant differences were found in the determinants of pre-pandemic and post-pandemic death after adjusting for age and AD, except for an association between the use of psychotropic medication and death in the post-pandemic period (odds ratio: 2.24; 95% confidence interval: 1.04–4.82). Vaccination against COVID-19 showed a marked protective effect against mortality (odds ratio: 0.0002; 95% confidence interval: 6.7e10−6 to 0.004). Conclusions: The appearance of COVID-19 has not impacted the overall trend of increase in mean age of death of adults with DS in our milieu, probably thanks to the very important protective effect of vaccination, which supports prioritising people with DS in future immunisation campaigns. The association between psychotropic medication use and mortality requires further explorationThis work was supported by a grant to Beatriz Sánchez (grant no. 2021b-2088) and Diego Real de Asúa (grant no. 2021a-2069) from the Fondation Jérôme Lejeun

    From local monitoring to a broad-scale viability assessment: a case study for the Bonelli’s Eagle in western Europe

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    Population viability analysis (PVA) has become a basic tool of current conservation practice. However, if not accounted for properly, the uncertainties inherent to PVA predictions can decrease the reliability of this type of analysis. In the present study, we performed a PVA of the whole western European population (France, Portugal, and Spain) of the endangered Bonelli's Eagle (Aquila fasciata), in which we thoroughly explored the consequences of uncertainty in population processes and parameters on PVA predictions. First, we estimated key vital rates (survival, fertility, recruitment, and dispersal rates) using monitoring, ringing, and bibliographic data from the period 1990-2009 from 12 populations found throughout the studied geographic range. Second, we evaluated the uncertainty about model structure (i.e., the assumed processes that govern individual fates and population dynamics) by comparing the observed growth rates of the studied populations with model predictions for the same period. Third, using the model structures suggested in the previous step, we assessed the viability of both the local populations and the overall population. Finally, we analyzed the effects of model and parameter uncertainty on PVA predictions. Our results strongly support the idea that all local populations in western Europe belong to a single, spatially structured population operating as a source-sink system, whereby the populations in the south of the Iberian Peninsula act as sources and, thanks to dispersal, sustain all other local populations, which would otherwise decline. Predictions regarding population dynamics varied considerably, and models assuming more constrained dispersal predicted more pessimistic population trends than models assuming greater dispersal. Model predictions accounting for parameter uncertainty revealed a marked increase in the risk of population declines over the next 50 years. Sensitivity analyses indicated that adult and pre-adult survival are the chief vital rates regulating these populations, and thus, the conservation efforts aimed at improving these survival rates should be strengthened in order to guarantee the long-term viability of the European populations of this endangered species. Overall, the study provides a framework for the implementation of multi-site PVAs and highlights the importance of dispersal processes in shaping the population dynamics of long-lived birds distributed across heterogeneous landscapes.Ministerio de Educación y Ciencia CGL200-64805/BOS CGL2010-17056 SAB-2006-0014/Roge

    Bistable Hofmann-Type FeII Spin-Crossover Two-Dimensional Polymers of 4-Alkyldisulfanylpyridine for Prospective Grafting of Monolayers on Metallic Surfaces

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    [EN] Aiming at investigating the suitability of Hofmann-type two-dimensional ( 2D) coordination polymers {Fe-II(L-ax)(2)[M-II(CN)(4)]} to be processed as single monolayers and probed as spin crossover (SCO) junctions in spintronic devices, the synthesis and characterization of the MII derivatives (M-II = Pd and Pt) with sulfur-rich axial ligands (L-ax = 4-methyl- and 4-ethyl-disulfanylpyridine) have been conducted. The thermal dependence of the magnetic and calorimetric properties confirmed the occurrence of strong cooperative SCO behavior in the temperature interval of 100-225 K, featuring hysteresis loops 44 and 32.5 K/21 K wide for PtII-methyl and Pt-II/Pd-II- ethyl derivatives, while the Pd-II-methyl derivative undergoes a much less cooperative multistep SCO. Excluding Pt-II-methyl, the remaining compounds display light-induced excited spin-state trapping at 10 K with T-LIESST temperatures in the range of 50-70 K. Single-crystal studies performed in the temperature interval 100-250 K confirmed the layered structure and the occurrence of complete transformation between the high- and low-spin states of the Fe-II center for the four compounds. Strong positional disorder seems to be the source of elastic frustration driving the multistep SCO observed for the Pd-II-methyl derivative. It is expected that the peripheral disulfanyl groups will favor anchoring and growing of the monolayer on gold substrates and optimal electron transport in the device.This work was supported by the Spanish Ministerio de Ciencia e Innovacion (MICINN) and FEDER founds (No. PID2019-106147GB-I00), Unidad de Excelencia Maria de Maeztu (Nos. MDM2015-0538-18-2, CEX2019-000919-M) and EU Framework FET-OPEN project COSMICS (Grant Agreement No. 766726). R.T.C. and M.M.S. thank the MICINN for a predoctoral grant.Turo-Cortés, R.; Valverde-Muñoz, FJ.; Meneses-Sánchez, M.; Muñoz Roca, MDC.; Bartual-Murgui, C.; Real, JA. (2021). Bistable Hofmann-Type FeII Spin-Crossover Two-Dimensional Polymers of 4-Alkyldisulfanylpyridine for Prospective Grafting of Monolayers on Metallic Surfaces. Inorganic Chemistry. 60(12):9040-9049. https://doi.org/10.1021/acs.inorgchem.1c0101090409049601

    Monte-Carlo Analysis of the Influence of the Electrical Component Tolerances on the Behavior of Series-Series- and LCC-Compensated IPT Systems

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    The use of compensation networks increases the power transfer capability of inductive power transfer (IPT) systems in the battery charging process of electric vehicles (EVs). Among the proposed topologies, the Series-Series (SS) and the LCC networks are currently in widespread use in wireless battery chargers based on IPT systems. This paper focuses on the study of the behavior of both compensation topologies when they are detuned due to the tolerances of their components. To compare their performances, a Monte-Carlo analysis was carried out using Simulink and MATLAB. The tolerance values, assigned independently to each component, fall within a [−20, 20] % range according to a normal distribution. Histograms and scatter plots were used for comparison purposes. The analysis reveals that the LCC network allows a tighter control over the currents that flow through the magnetic coupler coils. Moreover, it was found that the increments in those currents can be limited to some extent by selecting capacitors featuring low tolerance values in the LCC compensation. Nevertheless, the SS network remains an appropriate choice if size and cost are essential constraints in a given design

    Control Scheme of a Bidirectional Inductive Power Transfer System for Electric Vehicles Integrated into the Grid

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    Inductive power transfer (IPT) systems have become a very effective technology when charging the batteries of electric vehicles (EVs), with numerous research works devoted to this field in recent years. In the battery charging process, the EV consumes energy from the grid, and this concept is called Grid-to-Vehicle (G2V). Nevertheless, the EV can also be used to inject part of the energy stored in the battery into the grid, according to the so-called Vehicle-to-Grid (V2G) scheme. This bidirectional feature can be applied to a better development of distributed generation systems, thus improving the integration of EVs into the grid (including IPT-powered EVs). Over the past few years, some works have begun to pay attention to bidirectional IPT systems applied to EVs, focusing on aspects such as the compensation topology, the design of the magnetic coupler or the power electronic configuration. Nevertheless, the design of the control system has not been extensively studied. This paper is focused on the design of a control system applied to a bidirectional IPT charger, which can operate in both the G2V and V2G modes. The procedure design of the control system is thoroughly explained and classical control techniques are applied to tailor the control scheme. One of the advantages of the proposed control scheme is the robustness when there is a mismatch between the coupling factor used in the model and the real value. Moreover, the control system can be used to limit the peak value of the primary side current when this value increases, thus protecting the IPT system. Simulation results obtained with PSCADTM/EMTDCTM show the good performance of the overall system when working in both G2V and V2G modes, while experimental results validate the control system behavior in the G2V mode.Inductive power transfer (IPT) systems have become a very effective technology when charging the batteries of electric vehicles (EVs), with numerous research works devoted to this field in recent years. In the battery charging process, the EV consumes energy from the grid, and this concept is called Grid-to-Vehicle (G2V). Nevertheless, the EV can also be used to inject part of the energy stored in the battery into the grid, according to the so-called Vehicle-to-Grid (V2G) scheme. This bidirectional feature can be applied to a better development of distributed generation systems, thus improving the integration of EVs into the grid (including IPT-powered EVs). Over the past few years, some works have begun to pay attention to bidirectional IPT systems applied to EVs, focusing on aspects such as the compensation topology, the design of the magnetic coupler or the power electronic configuration. Nevertheless, the design of the control system has not been extensively studied. This paper is focused on the design of a control system applied to a bidirectional IPT charger, which can operate in both the G2V and V2G modes. The procedure design of the control system is thoroughly explained and classical control techniques are applied to tailor the control scheme. One of the advantages of the proposed control scheme is the robustness when there is a mismatch between the coupling factor used in the model and the real value. Moreover, the control system can be used to limit the peak value of the primary side current when this value increases, thus protecting the IPT system. Simulation results obtained with PSCADTM/EMTDCTM show the good performance of the overall system when working in both G2V and V2G modes, while experimental results validate the control system behavior in the G2V mode

    A Discrete-Time Control Method for Fast Transient Voltage-Sag Compensation in DVR

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    This paper presents a discrete-time domain control scheme for balanced voltage sag compensation using a Dynamic Voltage Restorer (DVR), which is recognized to be an appropriate and economical power electronic device with which to ameliorate these disturbances. The proposed control method is implemented in the synchronous reference frame (SRF), with two nested regulators, one of which includes an integral action. This algorithm has some advantages with respect to other control algorithms, such as the fact that the proposed methodology permits all the closed-loop poles of the DVR system to be placed in the desired locations in order to de ne the dynamical behavior with a reduction in the number of the electrical magnitudes to be measured and without the need for state observers, as occurs in traditional control methods. What is more, the well-known inner current loop implemented in other control schemes, which is employed to attenuate the resonance of the plant, is unnecessary. Furthermore, the unbalanced voltage sag compensation can be achieved by adding a ``plug-in'' controller and following the same methodology presented for balanced voltage sags to design the controller. The good performance of the proposed control scheme is validated by means of simulation and experimental results carried out with a 5 kW DVR laboratory prototype. The discrete-time control method is also compared with two control schemes previously proposed in literature

    Control and restrictions of a hybrid renewable energy system connected to the grid: a battery and supercapacitor storage case

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    This paper studies a Hybrid Renewable Energy System (HRES) as a reliable source of the power supply in the case of the connection to the grid. The grid connection imposes restrictions to the power delivered and harmonic content on the HRES. This causes the HRES to use multiple control systems and subsystems, as the normalization of the measurements, the current control, active harmonic compensation, synchronization, etc., described in this paper. Particular attention was paid to interactions in the storage system of the HRES. The durability of the HRES can be increased by the combination of the supercapacitors and batteries. This requires a power management solution for controlling the energy storage system. The aim of the supercapacitors is to absorb/inject the high-frequency fluctuations of the power and to smooth out the power of the batteries system of the HRES. This can be possible owing to the use of a low-pass second order filter, explained in this paper, which separates the high-frequency component of the storage system reference for the supercapacitor from the low-frequency component for the batteries system. This solution greatly increases the reliability and durability of the HRES

    Epitaxial thin-film vs single crystal growth of 2D Hofmann-type iron(II) materials: a comparative assessment of their bi-stable spin crossover properties

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    Integration of the ON−OFF cooperative spin crossover (SCO) properties of FeII coordination polymers as components of electronic and/or spintronic devices is currently an area of great interest for potential applications. This requires the selection and growth of thin films of the appropriate material onto selected substrates. In this context, two new series of cooperative SCO two-dimensional FeII coordination polymers of the Hofmann-type formulated {FeII(Pym)2[MII(CN)4]·xH2O}n and {FeII(Isoq)2[MII(CN)4]}n (Pym = pyrimidine, Isoq = isoquinoline; MII = Ni, Pd, Pt) have been synthesized, characterized, and the corresponding Pt derivatives selected for fabrication of thin films by liquid-phase epitaxy (LPE). At ambient pressure, variable-temperature single-crystal X-ray diffraction, magnetic, and calorimetric studies of the Pt and Pd microcrystalline materials of both series display strong cooperative thermal induced SCO properties. In contrast, this property is only observed for higher pressures in the Ni derivatives. The SCO behavior of the {FeII(L)2[PtII(CN)4]}n thin films (L = Pym, Isoq) were monitored by magnetization measurements in a SQUID magnetometer and compared with the homologous samples of the previously reported isostructural {FeII(Py)2[PtII(CN)4]}n (Py = pyridine). Application of the theory of regular solutions to the SCO of the three derivatives allowed us to evaluate the effect on the characteristic SCO temperatures and the hysteresis, as well as the associated thermodynamic parameters when moving from microcrystalline bulk solids to nanometric thin films
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