Aprendiendo a estudiar las clases en el club de apoyo matemático del Huila.

Tradicionalmente ha sido el interés de muchos investigadores conocer las causas de los problemas relacionados con la enseñanza y el aprendizaje de la matemática, y el bajo rendimiento de los estudiantes en esta área; entre las principales se encuentran: los problemas en la formación de los profesores, la desmotivación y falta de interés hacia la matemática, la falta de recursos, la escasa relación entre lo que se enseña y los resultados recientes de investigación, los inconvenientes laborales de los docentes y los problemas socioculturales de los aprendientes, viendo esta situación nos tomamos en la tarea de investigar y poder ayudar con este problema implementando un modelo de clases diferente, usando el modelo de los japoneses, ellos usan tres pasos muy importantes que es la planificación de la clase, la implementación y lo más importante la evaluación, ya que esta nos indica si fue un éxito la clase

Mechanical model to approximate the behaviour of dowel-type joints with expansive kits in timber structures

Congreso celebrado en la Escuela de Arquitectura de la Universidad de Sevilla desde el 24 hasta el 26 de junio de 2015.This work presents some advanced 3D mechanical models, developed using the finite element method, for dowel-type joints with and without expansive kits used in timber structures. Some key points in the design of the models are the correct calculation of the design load working on the joint, the approximation of the mechanical behaviour of the different materials which constitute these joints, the accurate description of the contact zone between timber and dowel and finally the mechanism proposed to model the effect of the expansive kit using the tools available in the commercial finite element program used. The results obtained from the models have shown a good agreement with a battery of empirical tests carried out to complete the work, and the comparisons between the results of the models with and without expansive kits show very interesting outcomes

Design and calculation of dowel‐type joints in timber structures : Behaviour of load against displacement

Congreso celebrado en la Escuela de Arquitectura de la Universidad de Sevilla desde el 24 hasta el 26 de junio de 2015.A joint system widely used in the construction of timber structures is based on the use of dowels, which transmit efforts between the timber elements. In these connections, it is attempted to reduce the diameter of the dowel, because large diameters increase the possibility of brittle fracture. In the present work, based on the approach of the European Yield Model that provides the load capacity of the joint, the stress distribution is analyzed in detail and a model is proposed. This model takes into account the slip of the joint and the propagation of the yield areas near the contact surfaces between dowel and timber, as the load increases. An iterative method that links load and slip equations is developed. It also provides information to improve the joint design, especially taking into account its stiffness behaviour. The results obtained from this analytical model have been compared with those from empirical tests of different samples, showing a good agreement

THE ADVANTAGES OF EVAPORATION IN MICRO-SCALE CHANNELS TO COOL MICROELETRONIC DEVICES

In this paper, the importance of the development of new high power density thermal management systems for electronic devices is assessed. It is described the new heat sink technologies under development to be used in the cooling of microprocessors. The main difficulties to be overcome before the spreading of one specific heat sink configuration are identified. At the end, it is concluded that a heat sink based on flow boiling in micro-scale channels is the most promising approach

Comparison of 30 THz impulsive burst time development to microwaves, H-alpha, EUV, and GOES soft X-rays

The recent discovery of impulsive solar burst emission in the 30 THz band is raising new interpretation challenges. One event associated with a GOES M2 class flare has been observed simultaneously in microwaves, H-alpha, EUV, and soft X-ray bands. Although these new observations confirm some features found in the two prior known events, they exhibit time profile structure discrepancies between 30 THz, microwaves, and hard X-rays (as inferred from the Neupert effect). These results suggest a more complex relationship between 30 THz emission and radiation produced at other wavelength ranges. The multiple frequency emissions in the impulsive phase are likely to be produced at a common flaring site lower in the chromosphere. The 30 THz burst emission may be either part of a nonthermal radiation mechanism or due to the rapid thermal response to a beam of high-energy particles bombarding the dense solar atmosphere.Comment: accepted to Astronomy and Astrophysic

Global stability analysis of axisymmetric liquid-liquid flow focusing

Article number A10We analyse both numerically and experimentally the stability of the steady jetting tip streaming produced by focusing a liquid stream with another liquid current when they coflow through the orifice of an axisymmetric nozzle. We calculate the global eigenmodes characterizing the response of this configuration to small-amplitude perturbations. In this way, the critical conditions leading to the instability of the steady jetting tip streaming are determined. The unstable perturbations are classified according to their oscillatory character and to the region where they originate (convective and absolute instability). We derive and explain in terms of the velocity field a simple scaling law to predict the diameter of the emitted jet. The numerical stability limits are compared with experimental results, finding reasonable agreement. The experiments confirm the existence of the two instability mechanisms predicted by the global stability analysisMinisterio de Economía, Industria y Competitividad (España) DPI2016-78887Junta de Extremadura GR18175Junta de Andalucía P18-FR-362