La eficiencia terminal en programas de licenciatura y su relación con la calidad educativa

Aún cuando la equidad sigue siendo el mayor reto del sistema educativo mexicano y que durante el siglo pasado el gobierno federal dedicó gran parte de sus esfuerzos a la expansión de dicho sistema, lo cierto es que la calidad de los servicios educativos no ha sido atendida con la misma intensidad. La calidad educativa abarca conceptos como el de pertinencia, cobertura, niveles de desempeño, eficacia y eficiencia y bajo este concepto, resulta fácilmente discernible concebir los problemas de baja eficiencia terminal, rezago académico y deserción como manifestaciones de una falta de calidad del proceso educativo. Se presentan los resultados de un estudio relacionado con dichos parámetros efectuado en una muestra conformada por cinco generaciones dentro del programa de Ingeniería Civil en la Universidad Autónoma de San Luis Potosí, a fin de identificar las causas relacionadas con la baja eficiencia terminal que de manera general afecta a nuestros programas. Se propone una serie de alternativas a fin de abatir dichos índices e incrementar la eficacia de los planes académicos, alternativas que se traducen en acciones tendientes a una mayor promoción de las carreras de ingeniería, modificaciones en los planes curriculares e incrementos en la efectividad de las tutorías individualizadas

Thermal and electrohydrodynamic plumes: a compartive study

This paper deals with self similar thermal and electrohydrodynamic (EHD) plumes. The former arises from hot lines or points, whereas the latter arises when sharp metallic contours submerged in non conducting liquids support high electrostatic potential, resulting in charge injection. Although the motive force is buoyancy in one case and Coulomb force in the other, it is shown that the solution for EHD plumes is the same as for thermal plumes in the limit of large Prandtl numbers. We present the analysis of axisymmetric plumes for large values of Prandtl number, and this analysis is subsequently applied to EHD plumes. The validity of the approximations for EHD plumes is discussed in the light of experimental data.Ministerio de ciencia y tecnología PB93-118

Hypnos: a Hardware and Software Toolkit for Energy-Aware Sensing in Low-Cost IoT Nodes

Through the Internet of Things, autonomous sensing devices can be deployed to regularly capture environmental and other sensor measurements for a variety of usage scenarios. However, for the market segment of stand-alone, self-sustaining small IoT nodes, long term deployment remains problematic due to the energy-constrained nature of these devices, requiring frequent maintenance. This article introduces Hypnos, an open hardware and software toolkit that aims to balance energy intake and usage through adaptive sensing rate for low-cost Internetconnected IoT nodes. We describe the hardware architecture of the IoT node, an open hardware board based on the Arduino Uno form-factor packing the energy measurement circuitry, and the associated open source software library, that interfaces with the sensing node’s microcontroller and provides access to the low-level energy measurements. Hypnos comes equipped with a built-in, configurable, modified sigmoid function to regulate duty cycle frequency based on energy intake and usage, yet developers may also plug in their custom duty/sleep balancing function. An experiment was set up, whereby two identical boards ran for two months: one with the Hypnos software framework and built-in energy balancing function to regulate sensing rate and the other with fixed sensing rate. The experiment showed that Hypnos is able to successfully balance energy usage and sensing frequency within configurable energy ranges. Hereby, it increases reliability by avoiding complete shutdown, while at the same time optimizing performance in terms of average amount of sensor measurements

Complex flow patterns at the onset of annular electroconvection in a dielectric liquid subjected to an arbitrary unipolar injection

We numerically investigated the annular electroconvection that takes place in a dielectric liquid lying between two concentric cylinder electrodes. A uniform injection of arbitrary strengths either from the inner or outer cylinder introduces free charge carriers into the system, and the resulting Coulomb force induces electroconvection. The problem is characterized by a linear instability that corresponds to the onset of flow motion. The linear stability criteria were determined from direct numerical results and by linear stability analysis, and the results obtained with the two approaches show an excellent agreement. We focused on the fully developed flow pattern in the finite amplitude regime. We observed very different flow motions that were highly dependent on the injection strength.Ministerio de Ciencia y Tecnología FIS2011-25161Junta de Andalucía P10-FQM-5735Junta de Andalucía P09-FQM-458

Chilean EFL teachers`perceptions of their working condition in the private, semi -private and public school systems

Tesis (Profesor de Inglés para la Enseñanza Básica y Media y al grado académico de Licenciado en Educación)This study followed a quantitative survey research design. The main purpose of the research was to explore Chilean English teachers’ perceptions of their working conditions, and compare the perceptions of teachers from the public, semi-private and private school systems. The data was collected by applying a questionnaire, a technique used in quantitative research. Sixty three teachers from forty six schools of the three educational sectors polled, answered the questionnaire using a 5-point Likert scale in order to express their perceptions regarding their working conditions. In the analysis process, the information collected was presented descriptively. In general, the participants showed positive perceptions concerning school environment and school support from their school authorities, but negative perceptions regarding salary, workload, time for non-instructional activities and society perceptions toward their profession.El presente estudio utilizó el diseño de encuesta cuantitativa. El propósito principal de nuestra investigación fue explorar las percepciones de los profesores de inglés chilenos acerca de sus condiciones laborales, y comparar estas percepciones de los profesores del sistema público, subvencionado y privado de la educación. La información fue recopilada a través de la aplicación de un cuestionario; técnica usada en el método cuantitativo de investigación. Sesenta y tres profesores de cuarenta y seis colegios de los tres sectores educacionales: público, subvencionado y privado, contestaron la encuesta usando la escala Likert del 1 al 5, de manera de obtener sus percepciones acerca de sus condiciones laborales. En el proceso de análisis, la información recolectada fue presentada descriptivamente. De manera general, los participantes demostraron percepciones positivas de acuerdo al clima laboral y el apoyo de las autoridades de los colegios; sin embargo, las percepciones fueron negativas acerca de su salario, carga laboral, tiempo para actividades extra curriculares y las percepciones de la sociedad acerca de la profesión docente

Electroconvection in a dielectric liquid between two concentric half-cylinders with rigid walls: Linear and nonlinear analysis

We study the linear stability and nonlinear behavior of the electroconvection between two concentric halfcylinders with no-slip conditions on all boundaries. The no-slip condition makes impossible to apply the standard modal approach. Hence, we apply a finite element technique similar to the one we have used in a previous paper about the electroconvection in a rectangular enclosed domain. When compared to the classical problem of electroconvection between two full concentric cylinders, the linear criterion is higher, due to the viscous shear introduced by the lateral walls. As a consequence, the structure of the eigenmodes is very different. There is a repulsion between modeswith the same symmetry, forcing pairs of modes to cross each other repeatedly. For inner injection and small value of the ratio between the inner and outer radii the no-slip condition changes the nature of the bifurcation from subcritical to supercritical, while it is always subcritical for outer injection. To understand this behavior, we perform a modal analysis using the eigenfunctions obtained from the linear stability analysis as modal basis. We show that the supercritical branch is originated by the nonorthogonality of the modes when no-slip boundary conditions are imposed. These mechanism explains the previously unexplained appearance of the supercritical branch in the enclosed rectangular configuration.Ministerio de Economía y Competitividad FIS2014-54539-

Onset of convection in a finite two-dimensional container due to unipolar injection of ions

This work addresses the stability of a two-dimensional plane layer of a dielectric liquid enclosed in wall bounded cavities of different aspect ratios and subjected to unipolar injection of ions. Numerical simulations have been conducted to investigate the effect of lateralwalls, especially in the development of the electroconvective instability. It is found that an unexpected change of the bifurcation nature occurs for certain cavity aspect ratios. We showthat above the linear stability threshold for the rest state a supercritical bifurcation arises. This bifurcation takes place at a given value Tc1 of the parameter T (the electric Rayleigh number). Then, a second subcritical bifurcation occurs at a second threshold Tc2, featuring a typical hysteresis loop with an associated nonlinear criterion Tf , which is very characteristic of the Coulomb-driven convection. This behavior has been confirmed by different numerical codes based on different numerical methods. The physical mechanism which leads to this situation is analyzed and discussed. The evolution of the bifurcation diagrams with the aspect ratio of the cavity is also provided and analyzed.Ministerio de ciencia y tecnología FIS2011-25161Junta de Andalucía P10-FQM-5735Junta de Andalucía P09-FQM-458

On two-dimensional finite amplitude electro-convection in a dielectric liquid induced by a strong unipolar injection

The hydrodynamic stability of a dielectric liquid subjected to strong unipolar injection is numerically investigated. We determined the linear criterion Tc (T being the electric Rayleigh number) and finite amplitude one Tf over a wide range of the mobility parameter M. A noticeable discrepancy is shown for Tf between our numerical prediction and the value predicted by stability analysis, which is due to the velocity field used in stability analysis. Recent studies revealed a transition of the flow structure from one cell to two with an increase in T. We demonstrate that this transition results in a new subcritical bifurcationMinisterio de Ciencia y Tecnología FIS2011-25161Junta de Andalucía P10-FQM-5735Junta de Andalucía P09-FQM-458