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Abstract This paper deals with the control of the series FACTS (Flexible AC Transmission Systems) devices for the coordination between their transient stability controller and POD (Power Oscillation Damping) controller in multi-machine power systems. The design aspects and their implementation in form of fuzzy-logic coordination controller are presented. Furthermore, ANFIS (Adaptive Neuro-Fuzzy Inference System) is employed for the training of the proposed fuzzy-logic controller. The local signals of the FACTS devices are applied to achieve the coordination objectives. Digital simulations of multi-machine power system subjected to a wide variety of disturbances validate the efficiency of this approach. The proposed control scheme is not only robust, but also simple and easy to be realized in power systems.

Abstract The combined production of electricity, heat and cold by a polygeneration system connected to a district heating and cooling network can provide high energy utilization efficiency. The inherent complexity of simultaneous production of different services and the high variability in the energy demand make combined cooling and heating systems performance highly dependent on the operational strategy. In this paper, an operational optimization method based on the moving average of real-time measurements of energy demands and ambient conditions is proposed. Real energy demand data from a district heating and cooling network close to Barcelona, Spain, are used to test the method. A complex polygeneration system is considered, consisting of an internal combustion engine, a double-effect absorption chiller, an electric chiller, a boiler and a cooling tower. A detailed modelling of the system is provided, considering partial load behavior of the components and ambient conditions effects. Results of the real-time optimal management are discussed and compared to traditional operational strategies and to the ideal optimal management achievable with perfectly accurate forecast of energy demands. Moreover, the optimal width of the window adopted for the moving average of real-time data is identified.

Abstract The 21st Conference of the Parties (COP21) of the United Nations Framework Convention on Climate Change (UNFCCC) marked a milestone in the course of international efforts on global climate action. As part of the COP21 side events, on December 4th the Lima Paris Action Agenda presented a half-day of presentations and round table discussions titled Focus on Private Finance. The event was supported by the Secretary-General of the United Nation, Caisse des Depots, and the I4CE Institute for Climate Economics. This conference report summarizes the findings of the session and the messages delivered by finance industry representatives. Significant investment in low carbon assets is required to maintain global temperature increases below 2 °C. The two resounding themes throughout the session were that in order to attract capital for low carbon investments fossil fuel subsidies must end and a higher carbon price is needed to incentivise investment. Furthermore, accounting and regulatory bodies need to implement more stringent disclosure and reporting requirements so that climate risk is properly understood by investors. There is significant appetite for investment in the low carbon sector which is demonstrated by the growth in the green bond market. Financial institutions have a role to play in aggregating, structuring and de-risking investments to facilitate private finance investment. Policy makers also need to improve the investment environment by creating consistent and stable long term policies which will give investors' confidence.

Abstract The sustainable indicators are characterized by a low degree of aggregation and a high amount of information. An indicator must show a synthetic representation of a real environmental, by using a value or a parameter, so that they can be easily used by policy makers. It is necessary to connect, therefore, the various systems in an appropriately integrated sustainable system. The indicators need to be aggregated based on the structure of the data. Each indicator must to be defined through a weight with reference to another weighted indicator. In this paper is illustrated the calculation of the assigned weights that uses a procedure based on fuzzy logic and to define a model that allows us to estimate the sustainability of a city. The final result is, therefore, a combination of values assigned by expert opinion for the various criteria, processed using fuzzy logic to obtain a weight with significant objectivity and as it is possible to estimate the sustainability of the city through the weights.

Abstract District heating dynamic models arise as an alternative approach to in-situ experimental investigations. The main advantage of dynamic modeling and simulation is the possibility to avoid technical and operational risks that might occur during in-situ experimental investigations (e.g. heat demand is not met, damages in the energy systems etc.). Within this study, the authors present two models for an existing district heating system in Cottbus, Germany. One model is developed using the tool EBSILON Professional, while the other one is developed using the Simscape toolbox for physical modeling in Matlab/Simulink. The models were experimentally validated against measured data from the considered district heating system. The results show that the Simscape model has a better fit and better response than the EBSILON model. Yet, some discrepancies were found between the measured and the simulated data and, therefore, the uncertainties of the models were addressed. A comparative study between both tools is presented. The EBSILON models permit only unidirectional flow, whereas the Simscape toolbox permits reverse flow. Nevertheless, the EBSILON model outperforms the Simscape model in computation time. In addition, this study presents an approach for dynamic thermo-hydraulic modeling of district heating networks. This approach is utilized to examine the role of district heating networks as heat storage as an optimization configuration. The numerical results show less start-ups for additional heat sources. Yet, higher heat losses from the network are observed due to the installation of unburied pipelines.

The possibility of artificially inducing activation of MII buffalo oocytes may allow us to evaluate indirectly the quality of oocytes after in vitro maturation. The aim of this work was to compare buffalo embryo development after IVF and after chemical activation by two different agents. A further goal was to evaluate the effects of aging of oocytes on post-parthenogenetic and post-fertilization development. In Experiment 1 cumulus-oocyte complexes (COCs) were recovered from abattoir-derived ovaries and matured in vitro. After IVM the COCs were either fertilized in vitro (positive control) or activated with ethanol and ionomycin, both followed by immediate exposure to 6-diethylaminopurine (6-DMAP) for 4 h. In vitro culture (IVC) was carried out up to the blastocyst stage. In Experiment 2 COCs were matured in vitro for 18, 21, 24, 27 and 30 h before activation was triggered with ethanol, followed by 6-DMAP. In Experiment 3 COCs were fertilized in vitro at 18, 21, 24, 27 and 30 h post-maturation. Ethanol activation gave better results than the IVF control group, with higher cleavage rate (71.4 +/- 7.8 versus 55.8 +/- 5.8, respectively; P < 0.05) and a higher proportion of oocytes developing into morulae-blastocysts (32.6 +/- 6.5 versus 22.9 +/- 7.5, respectively; P < 0.05). Within the activation groups, ethanol supported the highest development in terms of cleavage (71.4 +/- 7.8 versus 59.4 +/- 10.7; P < 0.05) and morulae-blastocysts rate (32.6 +/- 6.5 versus 25.7 +/- 8.3; n.s.). It was also demonstrated that aging negatively affects post-parthenogenetic and post-fertilization development.

Abstract The reliability of nuclear structures relates directly to the reliability of mechanical and electronic systems. Nuclear structures may be viewed as part of operational system as well as part of standby safety system. Except for proof loading, most of the load types, seen by nuclear structures, such as containments, primary piping, etc. during their design life, are random in time and space. Structural resistances, governed mainly by the respective material properties show also random characteristics. Methods of structural reliability, as discussed here, provide the means to process rationally the available information. Hence, they are an indispensable tool within the frame work of probabilistic risk analyses (PRA's). The probabilistic analysis is exemplified by determining the reliability of a containment structure sited in an area with strong seismicity.