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Η αυξανόμενη ανησυχία για την περιβαλλοντική βιωσιμότητα στον κλάδο των αερομεταφορών έχει ωθήσει τα αεροδρόμια παγκοσμίως να υιοθετήσουν στρατηγικές που αντιμετωπίζουν την πολύπλοκη αλληλεπίδραση μεταξύ οικονομικής ανάπτυξης, περιβαλλοντικών επιπτώσεων και κοινωνικής ευθύνης. Η παρούσα συγκριτική μελέτη εξετάζει τις στρατηγικές βιωσιμότητας του Διεθνούς Αερολιμένα Βιέννης (FWAG) και του Διεθνούς Αερολιμένα Αθηνών ΑΕ (ΔΑΑ), δύο σημαντικών ευρωπαϊκών αεροδρομίων, με στόχο την κατανόηση των προσεγγίσεών τους για την επίτευξη περιβαλλοντικής, κοινωνικής και οικονομικής βιωσιμότητας. Στο θεωρητικό υπόβαθρο διερευνάται η περίπλοκη σχέση μεταξύ της βιώσιμης ανάπτυξης, του τουρισμού και των αερομεταφορών, αναδεικνύοντας τις προκλήσεις και τις ευκαιρίες που παρουσιάζουν. Η μελέτη χρησιμοποιεί μια μεθοδολογία μελέτης περίπτωσης, αναλύοντας τις πρακτικές διαχείρισης της βιωσιμότητας, τα προγράμματα ανάπτυξης των εργαζομένων, τις περιβαλλοντικές πρωτοβουλίες και τις προσπάθειες δέσμευσης των ενδιαφερομένων μερών της FWAG και του ΔΑΑ. Η εξέταση αυτών των αεροδρομίων μέσα από ένα συγκριτικό φακό υπογραμμίζει τις μοναδικές στρατηγικές τους για την αντιμετώπιση των Στόχων Βιώσιμης Ανάπτυξης των Ηνωμένων Εθνών (ΣΒΑ) και την εκπλήρωση του ρόλου τους ως κρίσιμων μεταφορικών και πολιτιστικών πυλών. Τα ευρήματα αποκαλύπτουν ότι, ενώ και τα δύο αεροδρόμια έχουν δεσμευτεί για βιώσιμες πρακτικές, οι προσεγγίσεις τους είναι συγκεκριμένες ως προς το πλαίσιο. Το FWAG δίνει προτεραιότητα στην ενεργειακή απόδοση και τη μείωση των εκπομπών για να ευθυγραμμιστεί με την ιδιότητά του ως βασικού ευρωπαϊκού κόμβου. Αντίθετα, ο ΔΑΑ δίνει έμφαση στην εμπλοκή της κοινότητας, την πολιτιστική διατήρηση και την καινοτόμο περιβαλλοντική διαχείριση στο ρόλο του ως πύλη εισόδου στην πολιτιστική κληρονομιά της Ελλάδας. Η ανάλυση καταδεικνύει ότι η βιώσιμη ανάπτυξη του αεροδρομίου είναι ένα πολύπλευρο εγχείρημα που περιλαμβάνει περιβαλλοντικές εκτιμήσεις, τη δέσμευση των ενδιαφερομένων μερών και την οικονομική βιωσιμότητα. Η μελέτη συμβάλλει στην κατανόηση της βιωσιμότητας των αεροδρομίων παρουσιάζοντας τον τρόπο με τον οποίο τα διαφορετικά επιχειρησιακά πλαίσια επηρεάζουν την υιοθέτηση προσαρμοσμένων στρατηγικών βιωσιμότητας. Καθώς η αεροπορική βιομηχανία αντιμετωπίζει προκλήσεις που σχετίζονται με τις περιβαλλοντικές επιπτώσεις, τη δέσμευση των ενδιαφερομένων μερών και την οικονομική βιωσιμότητα, οι γνώσεις από τις στρατηγικές της FWAG και του ΔΑΑ μπορούν να ενημερώσουν για τη μελλοντική λήψη αποφάσεων στον τομέα. Η παρούσα μελέτη προσφέρει πολύτιμες προοπτικές για την επίτευξη ενός ισορροπημένου και βιώσιμου μέλλοντος για τα αεροδρόμια παγκοσμίως.

The paper describes formation and spreading of dense shelf waters in the Adriatic Sea (North Adriatic Dense Water, NAdDW) during the winter of 2012 as a consequence of an intense and long cold air outbreak of northeasterly Bora winds. As a result, during February 2012 northern Adriatic Sea water temperature dropped to about 6 degrees C and density exceeded 1030 kg/m(3), most likely the maximum value since 1929. NAdDW dynamics has been investigated by means of a 3-D ocean-wave coupled model running on a high resolution and eddy-permitting grid. The numerical experiments have relied on the Coupled-Ocean-Atmosphere-Wave-Sediment-Transport (COAWST) system forced one-way with atmospheric forcings provided by the model COSMO-17. A suite of observational data has been used to characterize the Bora event and evaluate numerical model performance. At sub-basin scales, the newly formed waters flowing southerly have produced a water renewal of the northern Adriatic, as more than 50% of water volumes have left the basin. Dense waters volume transports, evaluated through different Adriatic cross-sections, have been modulated by tides (damped for the densest water masses) and reached about 1 Sv. The contribution of wave-induced forcings has been quantified and examined, indicating that these represent a major driving mechanism during NAdDW production and spreading phases. This work provides evidence that NAdDW is spread accordingly with two different mechanisms: at early stages of its formation, the wind-driven ocean circulation pushes newly formed waters to leave the northern basin with relatively high speeds (about 0.30 m/s). Later on, remaining NAdDW leaks slowly out (0.09 m/s as average) from the production site. Residence times of dense waters in the north, middle, and south Adriatic Sea are also documented. (C) 2014 Elsevier Ltd. All rights reserved.

Abstract The OECD/NEA Sandia Fuel Project provided unique thermal-hydraulic experimental data associated with Spent Fuel Pool (SFP) complete drain down. The study conducted at Sandia National Laboratories (SNL) was successfully completed (July 2009 to February 2013). The accident conditions of interest for the SFP were simulated in a full scale prototypic fashion (electrically heated, prototypic assemblies in a prototypic SFP rack) so that the experimental results closely represent actual fuel assembly responses. A major impetus for this work was to facilitate severe accident code validation and to reduce modeling uncertainties within the codes. Phase I focused on axial heating and burn propagation in a single PWR 17 × 17 assembly (i.e. “hot neighbors” configuration). Phase II addressed axial and radial heating and zirconium fire propagation including effects of fuel rod ballooning in a 1 × 4 assembly configuration (i.e. single, hot center assembly and four, “cooler neighbors”). This paper summarizes the comparative analysis regarding the final destructive ignition test of the phase I of the project. The objective of the benchmark is to evaluate and compare the predictive capabilities of computer codes concerning the ignition testing of PWR fuel assemblies. Nine institutions from eight different countries were involved in the benchmark calculations. The time to ignition and the maximum temperature are adequately captured by the calculations. It is believed that the benchmark constitutes an enlargement of the validation range for the codes to the conditions tested, thus enhancing the code applicability to other fuel assembly designs and configurations. The comparison of lumped parameter and CFD computer codes represents a further valuable achievement.

In this paper a tool for the evaluation of transmission system adequacy is presented. Although similar in the basic assumptions to the classic versions of the Fuzzy Power Flow (FPF), the approach has significant differences in the formulation. First, it is symmetrical (no influence of the slack bus in the results), so all the fuzzy power injections are in the same situation. Second, by including line constraints, only feasible deterministic power flows are accepted in the fuzzy variables calculations, leading to a more correct representation of the possible impact of uncertainty. Third, recalculation of the estimated node fuzzy injections leads to a clear picture of the repressed power flows and thus of the adequacy of the grid. On the other hand, the Constrained Fuzzy Power Flow (CFPF) separates completely the analysis of the network from the generation influence and costs, which is indispensable in a unbundled organization of the power system.

In the present work, a novel hybrid solar-based smart building energy system is introduced and studied. The system comprises innovative photovoltaic-thermal-cooling (PVTC) panels integrated with hot and cold storages with two-way interaction with electricity, heat, and cooling networks (if any). The proposed system is compared with PV-based systems integrated with battery and heat pump for a case study complex building in Aarhus, Denmark. The comparison is conducted by evaluating the performance and economic indicators and investigating the effect of significant parameters on each scenario via a parametric study. Furthermore, the optimal operating conditions and sizing of the proposed system are determined using the genetic algorithm method considering initial cost and traded energy with local energy networks as the objective functions. The comparison results show that the proposed solution is the most cost-effective scenario with the lowest initial cost of about 457,000 $ and a payback period of 6.6 years. This is mainly due to the simultaneous interaction with electricity/heat/cooling networks as well as the elimination of the battery and the heat pump, which are offered by the proposed scenario. It is shown that, in comparison to PV panels, the PVTC can produce 328.7 MWh and 125.6 MWh extra heat and cooling annually. The scatter distribution of significant parameters shows that the panel area and heat storage capacity are not sensitive parameters, and keeping the cold storage capacity at the lower bound is a techno-economically better option.

Abstract Building-integrated photovoltaic (BIPV) panels are emerging as a useful technology for helping to achieve net-zero energy buildings. At this time, the main drawback with BIPV systems is the cost per kilowatt per hour of electricity generated. Besides cheaper production of photovoltaic panels, increases in their efficiency can be obtained by reducing panel temperatures. This is often achieved by adding a cavity beneath the panels to allow ventilation of the rear of the panel. However, the details of airflow in the cavity and the effect on cooling have not been rigorously researched. Life-time enhancement against degradation is also an effective technique to reduce the cost of electricity generated. Moisture ingress and thermal stresses are among the primary reasons for degradation of BIPVs; these processes are directly affected by air and moisture flow around the panels. The surface temperature thermography and airflow observations performed in this work helps to understand the transport mechanisms above and below the panels. For this purpose, a novel setup was developed consisting of a building model with a mock BIPV panel plus a solar simulator placed inside an atmospheric wind tunnel. Particle image velocimetry (PIV) and infra-red thermography were performed to simultaneously monitor the surface temperature and airflow above and below the panel. The study clearly shows how the accelerated airflow within the cavity increases the heat exchange between the PV and airflow and consequently reduces the PV temperature. It is also shown that the stepped open arrangement of panels is more effective in reducing the temperature comparing to a flat arrangement. This arrangement also has a better resistant against the air and moisture ingress.

Consistent climate data and reliable sizing methods are fundamental for designing Technical Building Systems. This paper addresses both these aspects with reference to the Italian context analyzing 108 different locations. Regarding the climate data, a quality analysis through the application of rules and filters was performed on the locations. The results showed good data quality, with most sites having high percentages of usable material, although highlighting recursive criticalities in the detection of humidity and wind speed parameters. Regarding the sizing methods, a sensitivity analysis was carried on for the European standard EN ISO 15927-2 to evaluate its performances in selecting the Cooling Design Days in the 108 locations. The analysis highlighted great differences in terms of chosen Design Days when using different climatic parameters, showing at the same time a negligible influence of the wind speed on the selection process. Furthermore, a sizing process for a test building applied to the 108 locations was carried on by using the Cooling Design Days. The results highlighted that the Design Days obtained through the EN ISO method often give counterintuitive sizing outputs, even obtaining higher required powers for lower risk levels, the opposite of how it should be. This implies that a designer should be very careful in evaluating which parameters to use in the Design Day selection and if the output sizing powers obtained through them are reliable for its particular sizing process.