Capacitance Evaluation on Non-parallel Thick-Plate Capacitors by Means of Finite Element Analysis

[EN] In this work we show the influence of the edge-effect on the electric field distribution and, hence, on the inner and outer capacitance in an inclined-plate capacitor system surrounded by an insulating medium taking into account the thickness of the conducting plates for a complete set of dimensions and insulating characteristics. Where available, we compare our results with previously published works. Finally, using statistical tools, we obtain approximate expression for computing the relationship between capacitance and insulation material characteristics, insulation gap, plate dimensions and angle.Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Catalán Izquierdo, S. (2011). Capacitance Evaluation on Non-parallel Thick-Plate Capacitors by Means of Finite Element Analysis. Journal of Energy and Power Engineering. 5(4):373-378. doi:10.17265/1934-8975/2011.04.012S3733785

A Control Strategy for Combined Series-Parallel Pumps

[EN] When a solution is adopted for a pumping irrigation system, to variable or constant wealth, the engineer has to evaluate the different alternatives to decide the most suitable system of pumping. The majority of the companies of the sector, they choose for systems of pump gradation in parallel at constant speed, with what the variable that they control is the wealth. In this paper there is proposed a system of pumping that connects pumps in parallel and pumps in series, working at variable speed, controlled by an algorithm that allows that every bomb should work inside the area of maximum efficiency.Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Catalán Izquierdo, S. (2010). A Control Strategy for Combined Series-Parallel Pumps. Renewable Energy and Power Quality Journal. 1(8):1466-1469. http://hdl.handle.net/10251/92559S146614691

FEM Edge Effect and Capacitance Evaluation on Cylindrical Capacitors

[EN] The purpose of this paper is to show the influence of the edge-effect on the electric field distribution, and hence on the inner capacitance and outer capacitance of a cylindrical capacitor surrounded by an insulating medium. To generalize the results, a two-dimensional axisymmetric finite element model of a cylindrical capacitor has been generated and the problem has been resolved taking into account the distance between the conductors for a complete set of dimensions. The available obtained results have been compared with previous published works. Finally, using statistical tools, the mathematical expression for computing the relationship between capacitance and insulation gap and cylindrical plates dimensions has been obtained.Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Catalán Izquierdo, S. (2012). FEM Edge Effect and Capacitance Evaluation on Cylindrical Capacitors. Journal of Energy and Power Engineering. 6(12):2063-2069. doi:10.17265/1934-8975/2012.12.022S2063206961

Semejanza: una propuesta didáctica para 2º de E.S.O.

El trabajo propone una secuencia didáctica basada en la resolución de problemas para la enseñanza del concepto matemático de la semejanza. Se describe el campo de problemas, las técnicas para su resolución y las tecnologías que la sustentan

Magnetic anomalies of the NW Iberian continental margin and the adjacent abyssal plains

The NW Iberian margin is a hyperextended continental margin, formed during the opening of the North Atlantic Ocean, where a subsequent partial tectonic inversion has undergone during the Alpine Orogeny. This succession of tectonic episodes determines the magnetic signature of the margin. The Spanish Exclusive Economic Zone Project has carried out seven one-month cruises between 2001 and 2009. To extend and densify the spatial coverage, we have used data from the World Digital Magnetic Anomaly Map. Here, we describe the methodology used for the acquisition and data processing of the magnetic field data. The use of diverse instrumentation, a non-complete external field’s cancelation, and the use of different magnetic core field models, contributed to the total error budget. To reduce it, we have used a leveling algorithm which minimizes all these contributions. Finally, a statistical analysis was applied using crossover residuals, showing a resolution better than 28 nT

Capacitance evaluation on parallel-plate capacitors by means of finite element analysis

[EN] The electric field distribution produced by any disposition of insulating and conducting materials is a key aspect in electrical design, but exact values can only be obtained in simple geometries. In this work, using commercially available F.E.M. software we show the influence of the edge-effect on the electric field distribution of a two parallel-plane conducting plates system surrounded by an insulating medium taking into account the thickness of the conducting plates. We compare our results with previous published works. Finally, we obtain the relationship between capacitance and insulation characteristics, insulation gap, plate dimensions and plate thicknessCatalán Izquierdo, S.; Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Cavallé Sesé, F. (2009). Capacitance evaluation on parallel-plate capacitors by means of finite element analysis. Renewable Energy and Power Quality Journal. 1(7):613-616. http://hdl.handle.net/10251/92552S6136161

Analyzing the impact of the MPI allreduce in distributed training of convolutional neural networks

For many distributed applications, data communication poses an important bottleneck from the points of view of performance and energy consumption. As more cores are integrated per node, in general the global performance of the system increases yet eventually becomes limited by the interconnection network. This is the case for distributed data-parallel training of convolutional neural networks (CNNs), which usually proceeds on a cluster with a small to moderate number of nodes. In this paper, we analyze the performance of the Allreduce collective communication primitive, a key to the efficient data-parallel distributed training of CNNs. Our study targets the distinct realizations of this primitive in three high performance instances of Message Passing Interface (MPI), namely MPICH, OpenMPI, and IntelMPI, and employs a cluster equipped with state-of-the-art processor and network technologies. In addition, we apply the insights gained from the experimental analysis to the optimization of the TensorFlow framework when running on top of Horovod. Our study reveals that a careful selection of the most convenient MPI library and Allreduce (ARD) realization accelerates the training throughput by a factor of 1.2× compared with the default algorithm in the same MPI library, and up to 2.8× when comparing distinct MPI libraries in a number of relevant combinations of CNN model+dataset

Capacitance evaluation on perpendicular plate capacitors by means of finite elemental analysis

[EN] In this work we show the influence of the edge-effect on the electric field distribution, and hence on inner capacitance and outer capacitance of the inclined angle, of a inclined-plate capacitor system in a plane, surrounded by an insulating medium taking into account the thickness of the conducting plates for a complete set of dimensions and insulating characteristics. Where available we compare our results with previous published works. Finally, using statistical tools, we obtain the expression for computing the relationship between capacitance and insulation characteristics, insulation gap, plate dimensions and inclined angle.Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Catalán Izquierdo, S.; Cavallé Sesé, F. (2009). Capacitance evaluation on perpendicular plate capacitors by means of finite elemental analysis. Renewable Energy and Power Quality Journal. 1(7):617-621. http://hdl.handle.net/10251/92548S6176211

Modelization of earth electrode excited by atmospheric discharges based on FEM

[EN] The aim of this paper is to obtain the distribution of tensions in the land excited by currents type ray using different types of electrodes: the goad electrodes and the deep goad electrodes, and as an exceptional case an electrode type drags was used. In this work, the program ANSYS® that is based on the finite elements method (FEM) was used. After the simulation of the distribution of tensions, different parameters were obtained, such as the tensions of step (Vp) and of contact (Vc) which determine the security of the installation of put in the earth (PE) protection.Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Catalán Izquierdo, S.; Quijano Lopez, A. (2008). Modelization of earth electrode excited by atmospheric discharges based on FEM. Renewable Energy and Power Quality Journal. 1(6):727-732. http://hdl.handle.net/10251/92551S7277321