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Resumen A pesar de que en las últimas décadas, el gobierno colombiano a través del Ministerio de Transporte et al., (2006), IDU (2011) e INVIAS (2013), han venido desarrollando e implementando especificaciones técnicas y metodologías orientadas al mantenimiento, reparación y rehabilitación de las vías pavimentadas a nivel nacional y distrital; se advierte que estas medidas no han sido suficientes para contrarrestar las problemáticas asociadas a los pavimentos rígidos, entre las que se encuentra el agrietamiento del concreto. Para mitigar este tipo de problemáticas, a nivel internacional se ha promovido el estudio de diferentes métodos de autorreparación a través de la adición de cepas bacterianas, que favorezcan la precipitación de cristales de carbonato de calcio (CaCO3) como una posible alternativa para el relleno y sellado de fisuras en el concreto. En este trabajo se plantean dos objetivos esenciales: primero, realizar una aproximación al estado del arte sobre diferentes métodos que pueden permitir la “Autorreparación de fisuras en concreto rígido para pavimentos mediante la adición de bacterias bioprecipitadoras de carbonato de calcio”, como una posible alternativa para la reparación, mantenimiento y durabilidad de las estructuras de pavimento en concreto. En segundo lugar, se busca formular un diseño experimental que sirva como marco de referencia para realizar investigaciones sobre métodos biológicos de autorreparación de concreto en la Universidad Nacional de Colombia, factibles de aplicarse en nuestro medio. Para ello, inicialmente se realizó una revisión teórica y conceptual sobre los principales aspectos que intervienen en el proceso de autorreparación de fisuras en concreto mediante la adición de bacterias bioprecipitadoras de carbonato de calcio (CaCO3). Igualmente, se realizó una recopilación bibliográfica sobre diferentes artículos científicos que evalúan la efectividad de diferentes bacterias bioprecipitadoras de carbonato de calcio (CaCO3) en la autorreparación de fisuras, mediante pruebas de resistencia a la compresión, flexión y tracción, permeabilidad y absorción de agua. Con base en las experiencias previas, se planteó una propuesta de diseño experimental que incluyó: la selección de materiales y cepas bacterianas; diseño de mezcla, preparación de muestras con y sin adición de bacterias; realización de pruebas físicas, mecánicas y microscópicas, que permitan evaluar la eficiencia del método de autorreparación estudiado y aproximación de los costos para un eventual desarrollo de la propuesta “Diseño experimental sobre métodos biológicos de autorreparación del concreto”. Abstract. Over the last few decades, the Colombian government, through the ministry of transport et al, (2006), IDU (2011) e INVIAS (2013), have developed and implemented specific techniques and methodologies used for the repairing and upgrading of paved roads, both on national and district roads. It is noted that these measures have not been enough to counteract the problems associated with rigid pavements, including concrete cracking. To mitigate this type of problem, the study of different self-healing methods has been promoted internationally through the addition of bacterial strains, favoring the precipitation of calcium carbonate crystals (CaCO3) as a possible alternative for the filling and sealing cracks in concrete. In this study two essential objectives are propose: firstly, to make an approximation to the state of the art on different methods that will allow the "Self-healing of cracks in concrete on rigid pavement through the addition of bio-precipitating calcium carbonate bacteria", as a possible alternative for the repair, maintenance and durability of concrete pavement structures. Secondly, it is intended to formulate an experimental design that serves as a support point for research on biological methods of self-healing concrete at the National University of Colombia, feasible to be applied in our environment. For this, initially a theoretical and conceptual review was carried out on the principals aspects involved in the process of self-healing of cracks in concrete through the addition of bioprecipitating calcium carbonate (CaCO3) bacteria. Also, a bibliographical compilation was carried out on different scientific articles that evaluate the effectiveness of different bioprecipitating calcium carbonate (CaCO3) bacteria, in the self - healing of cracks, through tests of strength compression, flexure and traction, permeability and water absorption. Based on the previous experiences, a proposal of experimental design was proposed that includes the selection of materials and bacterial strains, the design of mixture, preparation of samples with and without addition of bacteria and physical, mechanical and microscopic tests that allow to evaluate the efficiency of the self-healing method studied. Maestría

This paper reports the results of two experimental campaigns aimed at studying the high-frequency response of a raceway containing low voltage power, telephone, and Ethernet cables, to external electromagnetic field illumination. The raceway was tested against HPEM transients inside a GTEM cell and low power fields inside a reverberation chamber (RC). The HPEM tests revealed that the low voltage power cables have the greatest coupling under a hyperband illumination, compared to telephone and Ethernet cables. The RC tests allowed the determination of statistical transfer functions from random incident field configurations into DM voltage in cable loads. The responses were found to be governed by the raceway under test at the lower frequencies (below 1 GHz). Between 0.2-1 GHz, the raceway gives about 10 dB higher coupling than a short patch cable. The difference is even greater at lower frequencies and for shielded cables. In the frequency band 1-3 GHz, little difference was observed between short patch cables and the full raceway, but both were still significantly higher than direct coupling to the measurement card. Beyond 3 GHz, the coupling is clearly dominated by the terminal equipment. The experiments performed in this work provide a better understanding of the expected induced voltages and currents in commercial cable systems when exposed to IEMI-like signals.

The work presented in this thesis concerns the dimensioning of an Energy Storage System (ESS) which will be used as an energy buffer for a grid-connected PV plant. This ESS should help managing the PV plant to inject electricity into the grid according to the requirements of the grid System Operator. It is desired to obtain a final production not below 1300kWh/kWp with a maximum ESS budget of 0.9€/Wp. The PV plant will be sited in Martinique Island and connected to the main grid. This grid is a small one where the perturbations due clouds in the PV generation are not negligible anymore. A software simulation tool, incorporating a model for the PV-plant production, the ESS and the required injection pattern of electricity into the grid has been developed in MS Excel. This tool has been used to optimize the relevant parameters defining the ESS so that the feed-in of electricity into the grid can be controlled to fulfill the conditions given by the System Operator. The inputs used for this simulation tool are, besides the conditions given by the System Operator on the allowed injection pattern, the production data from a similar PV-plant in a close-by location, and variables for defining the ESS. The PV production data used is from a site with similar climate and weather conditions as for the site on the Martinique Island and hence gives information on the short term insolation variations as well as expected annual electricity production. The ESS capacity and the injected electric energy will be the main figures to compare while doing an economic study of the whole plant. Hence, the Net Present Value, Benefit to Cost method and Pay-back period studies are carried on as dependent of the ESS capacity. The conclusion of this work is that it is possible to obtain the requested injection pattern by using an ESS. The design of the ESS can be made within an acceptable budget. The capacity of ESS to link with the PV system depends on the priorities of the final output characteristics, and it also depends on which economic parameter that is chosen as a priority.