Thermal and Lighting Consumption Savings in Classrooms Retrofitted with Shading Devices in a Hot Climate

Most educational buildings in southern Spain do not meet current energy requirements as weak thermal envelopes and the lack of cooling systems lead to severe discomfort in classrooms, especially when temperatures are above 30 °C. Given that global warming is expected to worsen this situation in coming decades, one of the first steps to be taken is to protect window openings from high levels of solar radiation by adding shading devices to reduce indoor temperatures and improve visual comfort. The aim of this research is to evaluate the reduction in thermal and lighting consumption in a classroom where a solar protection system in the form of an egg-crate shading device was installed. Two classrooms—one with an egg-crate device and another with no shading system—were monitored and compared for a whole year. The use of an egg-crate device in these classrooms reduced indoor operative temperatures during warmer periods while also improving indoor natural illuminance levels. Moreover, annual electric air conditioning consumption decreased by approximately 20%, with a 50% reduction in electric lighting consumption. These savings in electricity were largely conditioned by the use patterns observed in these ambient systems.Spanish government BIA2014-53949-RMinistry of Economy and Competitiveness, Spanish GovernmentEuropean Regional Development Fun

New Management Discourses: Difussion, impacts and resistances

El presente monográfico de Recerca titulado «Los nuevos discursos del management: contribuciones desde una perspectiva crítica», se compone de siete artículos de investigación y dos recensiones. A través de los diferentes escritos se pretende realizar un recorrido por el estado actual de los discursos del management y sus repercusiones no solo en el mundo del trabajo, sino en el grueso de la sociedad desde una perspectiva crítica. Así pues, a lo largo de las siguientes páginas el/la lector/a podrá transitar por los diferentes discursos que hoy en día caracterizan el espacio social. Nos referimos a marcos generales de sentido como el individualismo y la descolectivización de lo social, pero también a cuestiones más concretas como el emprendimiento y la precariedad; todos ellos componentes que conforman el escenario al que nos estamos remitiendo en todo momento, esto es, el del discurso neoliberal o el «nuevo espíritu del capitalismo» (Boltanski y Chiapello, 2002)

Estudio de la aerodinámica de una cometa de kitesurf incluyendo su forma

Este trabajo consiste en el desarrollo de un programa que evalúe de forma preliminar las fuerzas aerodinámicas sobre una cometa de kitesurf y la deformación que provocan estas a su tela. Este programa está planteado para favorecer el diseño de cometas y facilitar el cálculo de la fuerza que puede proporcionar la cometa al deportist

Guerra jurídica contra el personal militar un problema de seguridad nacional

La conformación de un derecho penal dirigido al desconocimiento del derecho natural de las fuerzas militares de ejercer el fuero militar, para respaldar la legalidad de sus procesos y acciones, ha determinado un movimiento que utiliza los derechos humanos y el derecho internacional humanitario, en beneficio de los grupos al margen de la ley con el objeto de vencer la capacidad de lucha y la moral del combatiente, descalificando el actuar y el proceder de la Fuerzas Militares, es una estrategia inteligente basada en la combinación de las formas de lucha, las cuales categorizan a la denominada guerra política, como estrategia para descalificar y suprimir a las víctimas y negarles su derecho a reclamar verdad, justicia y reparación, colocando al Estado y su institucionalidad en una encrucijada jurídica.The creation of a criminal law led to ignorance of the natural right of the military exercise military jurisdiction, to support the legality of its processes and actions, has led a movement that uses human rights and international humanitarian law for the benefit of groups outside the law in order to overcome the fighting capacity and morale of the fighter, disqualifying the act and the actions of the Armed Forces, is a smart strategy based on the combination of the forms of struggle, which categorizes the so-called political warfare as a strategy to discredit and invisible victims and deny them their right to demand truth, justice and reparation, placing the state and its institutions in a legal crossroads

Model and neural control of the depth of anesthesia during surgery

At present, the experimentation of anesthetic drugs on patients requires a regulation protocol, and the response of each patient to several doses of entry drug must be well known. Therefore, the development of pharmacological dose control systems is a promising field of research in anesthesiology. In this paper it has been developed a non-linear compartmental pharmacokinetic-pharmacodynamical model which describes the anesthesia depth effect on a sufficiently reliable way over a set of patients with the depth effect quantified by the Bi-Spectral Index. Afterwards, an Artificial Neural Network (ANN) predictive controller has been designed based on the depth of anesthesia model so as to keep the patient on the optimum condition while he undergoes surgical treatment. For the purpose of quantifying the efficiency of the neural predictive controller, a classical proportional-integral-derivative controller has also been developed to compare both strategies. Results show the superior performance of predictive neural controller during Bi- Spectral Index reference tracking.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Empirical and numerical analysis of an opaque ventilated facade with windows openings under Mediterranean climate conditions

In recent years, there has been growing concern regarding energy efficiency in the building sector with energy requirements increasing worldwide and now responsible for about 40% of final energy consumption in Europe. Previous research has shown that ventilated façades help to reduce energy use when cooling buildings in hot and temperate climates. Of the different ventilated façade configurations reported in the literature, the configuration of ventilated façade with window rarely has been studied, and its 3D thermodynamic behavior is deserving of further analysis and modeling. This paper examines the thermal behavior of an opaque ventilated façade with a window, in experimentally and numerical terms and its impact in energy savings to get indoor comfort. Field measurements were conducted during the winter, spring and summer seasons of 2021 using outdoor full scale test cells located in Seville (southern Spain). The modeling of the ventilated façade was carried out using a three-dimensional approach taking into account the 3D behavior of the air flow in the air cavity due to the presence of the window. The validation and comparison process using experimental data showed that the proposed model provided good results from quantitative and qualitative point of view. The reduction of the heat flux was assessed by comparing the energy performance of a ventilated façade with that of an unventilated façade. Both experimental and numerical results showed that the ventilated façade provided a reduction in annual total energy consumption when compared to the unventilated façade, being compensated the winter energy penalization by the summer energy savings. This reduction is about 21% for the whole typical climatic year showing the ability of the opaque ventilated façade studied to reduce energy consumption to insure indoor comfort, making its suitable for use in retrofitting the energy-obsolete building stock built in Spain in the middle decades of the 20 century

Indoor environmental assessment: comparing ventilation scenarios in pre- and post-retrofitted dwellings through test cells

In the next few years, outdoor temperature is expected to increase significantly as a result of climate change, a noticeable phenomenon, especially in the Mediterranean. In this future scenario, ventilation is a low-cost and useful strategy for tackling indoor overheating, mainly in energy-poor housing buildings. This research assesses the influence of different ventilation systems, air rates and schedules on the thermal comfort and indoor air quality of a residential retrofitted space when compared to an un-retrofitted environment, through test cell measurements. To do so, the methodology combines on-site monitoring with numerical models, simultaneously analysing both spaces under the same climate conditions. Results obtained show barely perceptible differences between the implementation of a mechanical ventilation system and a natural one, when it comes to thermal comfort in spaces with low thermal inertia, highlighting the clear advantage of energy and economic savings of the passive system

Making metals transparent: A circuit model approach

Solid metal films are well known to be opaque to electromagnetic waves over a wide frequency range, from low frequency to optics. High values of the conductivity at relatively low frequencies or negative values of the permittivity at the optical regime provide the macroscopic explanation for such opacity. In the microwave range, even extremely thin metal layers (much smaller than the skin depth at the operation frequency) reflect most of the impinging electromagnetic energy, thus precluding significant transmission. However, a drastic resonant narrow-band enhancement of the transparency has recently been reported. The quasi-transparent window is opened by placing the metal film between two symmetrically arranged and closely spaced copper strip gratings. This letter proposes an analytical circuit model that yields a simple explanation to this unexpected phenomenon. The proposed approach avoids the use of lengthy numerical calculations and suggests how the transmissivity can be controlled and enhanced by manipulating the values of the electrical parameters of the associated circuit model. � 2016 Optical Society of America.Ministerio de Economía y Competitividad TEC2013-41913-PJunta de Andalucía P12-TIC-143

Dynamical Equivalent Circuit for 1-D Periodic Compound Gratings

Metallic compound gratings are studied in this work by means of an analytical equivalent circuit approach in order to obtain its transmission and reflection properties when illuminated by a TM-polarized plane wave. A compound grating consists of the periodic repetition of a finite number of slits carved out of a thick metal slab (reflection grating) or connecting two separated open regions through groups of slits in the metal slab (transmission grating). The equivalent circuit is rigorously obtained starting from a simplified version of the integral equation for the electric field at the slits apertures. That equivalent circuit involves transmission-line sections that account for the fundamental and lowest order diffracted modes (which does give the 'dynamical' nature to the present equivalent circuit), and lumped components to model the effect of all the higher order diffracted modes. All the relevant and complex features of the spectra can be satisfactorily explained in terms of the topology and characteristics of the equivalent circuit. In contrast with some previously reported circuit models, all the dynamical and quasi-static circuit elements are analytically and explicitly obtained in terms of the geometric and electrical parameters of the grating. The accuracy of the approximate circuit model is very good over a very wide band, as it is demonstrated by comparison with full-wave data computed with commercial electromagnetic solvers.Ministerio de Economía y Competitividad TEC2013- 41913-PJunta de Andalucía P12-TIC-143

Analytical circuit model for 1-D periodic T-shaped corrugated surfaces

An analytical circuit model is obtained to study the reflection of TM polarized electromagnetic waves that impinge obliquely on a 1-D periodic corrugated surface consisting of dielectric-loaded T-shaped planar corrugations backed by an infinite ground plane. The model is based on transmission line theory and equivalent lumped-element circuits. For the case of perfect conductors, the topology of the circuit is directly inferred from a rigorous full-wave formulation of the periodic problem without using any heuristic argument. This procedure leads to fully analytical expressions for all the circuit parameters. Ohmic losses are further incorporated in the model under the assumption of strong skin effect. The results thus obtained are compared with those given by an accurate Method of Moments numerical code and HFSS software showing a very good agreement. The strong numerical efficiency as well as the good physical insight provided by the present equivalent circuit model can be advantageously employed for the analysis and/or design of a variety of devices. As examples of the latter, the circuit model is used for the first-stage design of an electrically thin hard impedance surface, a corrugated surface that prevents specular reflection, and an absorber.Ministerio de Ciencia e Innovación TEC2010-16948, CSD2008-0006