Papers by Santiago Sanchez
Comptes Rendus Biologies, 2013
This paper reports the role of darkling beetles Pimelia laevigata costipennis and Hegeter amaroid... more This paper reports the role of darkling beetles Pimelia laevigata costipennis and Hegeter amaroides (Tenebrionidae) as intermediate hosts of spiruroid nematodes parasites of the black rat and house mouse of El Hierro (Canary Islands). Larvae of spiruroid species were found in the two tenebrionids (18.1% in P. l. costipennis, 7.8% in H. amaroides), Streptopharagus greenbergi being predominant in both (16.1% and 7.1%, respectively), ahead of Mastophorus muris and Gongylonema type larva. The larval stages of S. greenbergi are described for the first time, and adult worms were obtained experimentally from an infected laboratory rat, allowing the identification of the species. Morphometric measurements of experimental adults match those of adults detected in naturally infected rats on the island. Molecular data for S. greenbergi, and the ITS nucleotide sequence of the genus Streptopharagus are also provided for the first time. After the isolation of S. greenbergi DNA and amplification of the ITS region, the ITS1 of this spirocercid was sequenced and deposited in the GenBank database.
Acta Parasitologica, 2012
This article reports the geographical and host distribution of the flea Stenoponia tripectinata o... more This article reports the geographical and host distribution of the flea Stenoponia tripectinata on the Canary Islands. S. tripectinata is widely distributed throughout the Mediterranean and North Africa as a parasite of Muridae rodents. To date, Gran Canaria is the only island of the archipelago where S. tripectinata had been found. In this report, S. tripectinata has appeared parasitizing 116 specimens of Mus musculus out of a total of 660, and only 2 Rattus rattus of 215 captured. All the trapped Muridae hosts found to be parasitized by S. tripectinata came from humid biotopes. The results showed that S. tripectinata is present on all the western Canary Islands and on one of the eastern islands, Gran Canaria, the only island already reported. The detection of S. tripectinata on El Hierro, La Palma, La Gomera and Tenerife represents the first records of this flea species on those Canary Islands.
Acta Parasitologica, 2012
The parasite fauna (protozoa, helminths and insects) of the two most widespread Murinae rodents i... more The parasite fauna (protozoa, helminths and insects) of the two most widespread Murinae rodents in El Hierro (Canary Islands, Spain), the black rat (Rattus rattus) and the house mouse (Mus musculus domesticus) was studied. Faunistic, ecological, ecotoxicological data, as well as information on the biology of some nematode parasites of R. rattus are provided. The present work is unprecedented in the Canary Islands, and provides the first data on the parasite biodiversity in Murinae from the archipelago. Concerning to parasitofaunas stands out: a) impoverishment of biodiversity of helminths respect of which have the same hosts in other islands; b) increasing the number of species of Siphonaptera, even compared with flea species that parasitize the same hosts from continental biotopes.
2012 IEEE 13th Workshop on Control and Modeling for Power Electronics (COMPEL), 2012
ABSTRACT In DC series-connection of wind turbines the common variable for the turbines is the DC ... more ABSTRACT In DC series-connection of wind turbines the common variable for the turbines is the DC current and thus the simplest control approach is to use current source type converter to perform the speed control of the generators for maximum power extraction. When using current source type converters like the Current Source or the matrix converter, LC filters are needed at the input of the generator to remove switching harmonics. Thus resonance can be an issue and special care needs to be taken when designing controllers. In this article a wind farm topology with series connected turbines is presented along with the wind energy conversion system inside in which a matrix converter performs speed control of the generator. To counteract resonance, three nested loops controlling respectively the turbine rotational speed, the stator current and the filter capacitor voltage are implemented. The tuning should be performed carefully so that the control is fast, stable and tracking the maximum power point. The system model is analyzed in the dq reference frame to find appropriate controllers for each loop and a method is presented to tune each controller in a systematic manner for a satisfactory system response. Simulation results are presented.
IEEE Transactions on Smart Grid, 2014
ABSTRACT The classical distribution system can evolve in a new concept of grid, where the distrib... more ABSTRACT The classical distribution system can evolve in a new concept of grid, where the distributed generation has a big impact. These changes take into account the use of power electronic devices. With these devices it is necessary to study the stability of the system in a new form due to their multi-current domain and the influence of the controllers applied to each device. The paper presents a methodology that takes into account the structure of a DC microgrid system and evaluates its stability. The stability analysis uses the computational continuation to obtain the conclusions. The real time simulation results present the grid behavior and validate the limits of operation.
2012 15th International Power Electronics and Motion Control Conference (EPE/PEMC), 2012
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2012 IEEE Third International Conference on Smart Grid Communications (SmartGridComm), 2012
ABSTRACT Real-time lossy compression of voltage and current measurements in an electrical grid is... more ABSTRACT Real-time lossy compression of voltage and current measurements in an electrical grid is considered. It is assumed that a compressed version of measurements needs to be transmitted to the control center to be used for line voltage compensation. This necessitates tight delay and high accuracy requirements. Acquiring high compression, while also maintaining a high-quality reconstruction is achieved via differential quantization of consecutive samples. Zero delay is made possible using sample-by-sample processing of signals. The proposed scheme consists of two adaptive quantizers on transformed versions of voltage and current signals using Park's transform. The quantizers incorporate a predictor which is based on spectral characteristics of the transformed signals. The objective is to compress the measurements as efficiently as possible, while keeping the voltage within the stipulated values by grid standards. The suggested scheme is then applied in a model of a micro-grid with a voltage source converter based controller. The trade-off between compression ratio and quality of the grid voltage and current in terms of deviation from nominal values is studied and discussed.
2013 IEEE Grenoble Conference, 2013
ABSTRACT The classical distribution system can evolve in a new concept of grid, where the distrib... more ABSTRACT The classical distribution system can evolve in a new concept of grid, where the distributed generation is a great factor. These changes take into account the use of power electronic devices. With these devices it is necessary to study the stability of the system in a new form due to their multi-current domain and the influence of the controllers applied to the each device. The paper presents a methodology that takes into account the structure of a DC system and evaluates its stability. The stability analysis applies the computational continuation to obtain the conclusions over the limits of safe operation. Finally, the simulation results present the grid behavior.
PES T&D 2012, 2012
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IEEE Transactions on Circuits and Systems I: Regular Papers, 2000
ABSTRACT In this paper we investigate the sine qua non condition of existence of equilibria for e... more ABSTRACT In this paper we investigate the sine qua non condition of existence of equilibria for electrical systems with external (AC or DC) sources furnishing constant power to the loads, which is a scenario encountered in modern applications. Two general cases are considered, when the system is i) linear time-invariant or ii) nonlinear, with dynamic behavior described by a port-Hamiltonian model with constant dissipation and switching interconnection matrix. The latter class includes the practically important case of power converters. For both cases necessary and sufficient conditions for existence of equilibria are given, which give an upper bound on the power dissipated in steady-state that should exceed the extracted constant power. The existence of the equilibrium is ensured if and only if the inequality is satisfied.
ABSTRACT This paper presents the stability analysis of a DC micro-grid fed by renewable sources a... more ABSTRACT This paper presents the stability analysis of a DC micro-grid fed by renewable sources and the future interconnection with an AC micro-grid. This interconnection is realized through a voltage source converter, and the operation of the micro-grid is in island mode. The stability is analyzed by the Nyquist criteria with the impedance relation method. The frequency response of the models was obtained by the injection of a perturbation current at the operation point. Where this perturbation was at the input of the converter used to export power from the DC grid. Other perturbation was applied at the node of the micro-grid to evaluate its impedance. Finally the simulations show the impedance representation of the systems, and the stability for the interconnection of them. The experimental verification shows the impedance of the converter with the same tendency as the representation obtained by the analytical and simulation.
Por definición, la clonación es el procedimiento de obtener una población de varios individuos ge... more Por definición, la clonación es el procedimiento de obtener una población de varios individuos genéticamente homogéneos a partir de uno solo mediante reproducción asexuada. El concepto de clonación puede aplicarse, en la ciencia moderna, tanto a nivel molecular como celular. En la actualidad, la clonación molecular es un procedimiento de laboratorio consolidado que se utiliza amplia y rutinariamente dentro de la biología molecular y la genética. Constituye una poderosa herramienta que ha producido ya relevantes aplicaciones de diagnóstico y terapéuticas en la moderna biomedicina, así como importantes usos industriales por lo que a animales y plantas se refiere.
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Papers by Santiago Sanchez