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Radiation is a form of energy where the angular variable of the direction of its photons has a primary importance, particularly for radiation concentration processes, which are essential tools to reach high temperatures from radiation beams (as the solar ones) with moderate intensities. Solar radiation cannot be used directly to feed thermodynamic cycles, and optical concentration must be applied to that goal. In general, reflection from mirrors is preferred to refraction by lenses in this case, because they have less optical aberrations. Concentration conveys very high temperatures in the receiver. However, the higher the temperature, the lower the efficiency of the solar thermal apparatus. Besides that, economy also suffers quite a lot when going to very high concentration factors, which is one of the main burdens in the development of Solar Thermal Energy. A new configuration of solar radiation concentrator is presented. It includes a salient innovation in the way the mirrors are given the right curvature by mechanical forces. Those mirrors are originally flat and do not need any special thermal treatment for this purpose. The whole device concept has been guided by the principle of thermo-economic coherence, which requires similar efforts in all degrees of freedom that have strong influence in the performance and cost of the system. The paper shows the decision tree that has oriented the project, following the principle of equilibrium in efforts, which leads to a design window of moderate values in the main variables. The prototype of this new configuration has already been built, and the first stage of research is considered to be finished, because the prototype has shown excellent conditions to include selected (fitting) technologies at a very low cost.

La información geoespacial es comúnmente proporcionada por servicios web estándar. Sin embargo, en muchos casos es difícil encontrar que servicios contienen la información deseada. Este artículo propone un proceso para construir un modelo geoespacial de datos enlazados que facilite la búsqueda de información geoespacial en la web.

Nowadays a trend focused on developing new tools in order to ease the decision making process in traffic central post facilities is clearly demanded by railway administrations. Also, hardware and software technical improvement allows new and more complex control and planning systems to be developed.In this paper a new tool developed for railway planning and traffic regulation is presented. Intelligent planning and traffic regulation is carried out with the help of a simulation tool that provides very valuable information to the planning and regulating tools of the way the railway line will react to the control orders. This simulator gives information of both mechanical and electrical behaviour of the system so electrical consumption can be taken into consideration in order to obtain an operational plan.The way the line planning is carried out can be described this way: First, planning tool gets the operator inputs to the tool that are mainly the starting position of the train units in the line, the interval between circulations throughout the day or the departure time of the train. Then the planning tool calculates the optimal theoretical schedule and the routing list for each station in the line according to the inputs, conditions and restrictions of the line. This theoretical planning is tested using the simulator and if it fulfils line operational requirements is stored as a valid plan. Finally, a traffic regulation tool is in charge of executing the theoretical plan. This tool compares the theoretical plan with the result of the operation of the railway line, calculates the deviation from the theoretical plan (conflict detection) and sends orders to the traffic control system trying to lessen the deviations from the theoretical plan (conflict resolution). If deviations can't be reduced, a new planning taking into consideration the actual state of the line is obtained in order to operate the line while a degraded situation is taking place. Then, once the degraded situation is overridden, the first theoretical plan is recovered if possible.