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Abstract: Buildings’ thermal-energetic assessment and the relative proposal of new technical solutions applied to both summer and winter analyses has a strategic role in increasing the year-round performance of buildings. Buildings’ dynamic analysis is by now a well-established procedure to study effective building energy performance given real climate considerations. Then in this work, a concise and effective methodology for analyzing buildings’ thermal performance in a dynamic environment is proposed and applied to different case studies, consisting of single-family residential buildings’ prototypes. This procedure is aimed to define different performance levels by proper non-dimensional indexes named thermal deviation indexes (TDI). These indexes values could express in a concise way buildings’ thermal behavior, different optimization strategies impact, sensitivity analysis results. Buildings’ prototypes representing the case studies are three free-floating houses where the architectural shape role and the sensitivity of different envelope features are analyzed, also supported by experimental results regarding envelope properties measured on existing residential buildings in Italy. The three prototypes are respectively designed to optimize summer or winter energy performance or to represent the typical Italian house before and after energy efficiency regulation is implemented. To better define the important envelope parameters necessary to calibrate the numerical models, experimental activities are conducted. In particular, thermal insulation level and roof reflectance, characterized by means of spectrophotometrical measurements, are measured both in the case of an old traditional Italian building and in the case of a modern building. The results of the dynamic analysis are expressed in terms of TDI values, to define buildings’ thermal performance with respect to the variation of all the considered architectural and envelope’s properties (i.e. architectural layout, mass and insulation, roof reflectance, Solar Heat Gain Coefficients of windows’ glasses, weather data) within a specific climatic context. For validating the proposed method, the obtained TDI results are compared with those obtained from existing procedures. In particular, the TDI values are correlated to an adaptive comfort indicator, for verifying how much the TDI could be effective for evaluating free-running buildings thermal performance during both summer and winter. [Copyright &y& Elsevier]

Abstract: Larderello–Travale is one of the few geothermal systems in the world that is characterized by a reservoir pressure much lower than hydrostatic. This is a consequence of its natural evolution from an initial liquid-dominated to the current steam-dominated system. Beneath a nearly impermeable cover, the geothermal reservoir consists of carbonate-anhydrite formations and, at greater depth, by metamorphic rocks. The shallow reservoir has temperatures in the range of 220–250°C, and pressures of about 20bar at a depth of 1000m, while the deep metamorphic reservoir has temperatures of 300–350°C, and pressures of about 70bar at a depth of 3000m. The 3D numerical code “TOUGH2” has been used to conduct a regional modeling study to investigate the production mechanism of superheated steam, the interactions between the geothermal field and the surrounding deep aquifers, and the field sustainability. All the available geoscientific data collected in about one century of exploration and exploitation have been used to provide the necessary input parameters for the model, which covers an area (4900km2) about 10 times wider than the Larderello–Travale geothermal field (400km2). The numerical model explains the origin of the steam extracted in about one century of exploitation and shows that, at the current level, the production is sustainable at least for the next 100 years. [ABSTRACT FROM AUTHOR]

Abstract: Useful geodynamic distinction of continental collision zones can be based on the degree of rheological coupling of colliding plates. Coupled active collision zones (which can be either retreating or advancing) are characterized by a thick crustal wedge and compressive stresses (i.e. Himalaya and Western Alps), while decoupled end-members (which are always retreating) are defined by a thin crustal wedge and bi-modal distribution of stresses (i.e., compressional in the foreland and extensional in the inner part of the orogen, Northern Apennines). In order to understand physical controls defining these different geodynamic regimes we conducted a 2D numerical study based on finite-differences and marker-in-cell techniques. In our experiments we systematically varied several major parameters responsible for the degree of rheological coupling between plates during collision such as convergence rate, crustal rheology and effective velocity of upward propagation of aqueous fluids and melts in the mantle wedge. Low convergence rates and fluids/melts propagation velocities favor continuous coupling and convergence between the plates. Coupled collision zones are characterized by continuous accretion of the weak upper continental crust resulting in the development of a thick and broad crustal wedge, by hot temperature in the inner parts of the orogen due to radiogenic heating of the thickened crust, by compressive orogenic stresses and appearance of a double seismogenic (brittle) layer involving upper crust and sub-Moho mantle. In contrast high convergence rates and fluid/melt percolation velocities produce efficient weakening of the mantle wedge and of the subduction channel triggering complete decoupling of two plates, mantle wedging into the crustal wedge and retreating style of collision. The evolution of fully decoupled collision zones are characterized by the disruption of the accretionary wedge, formation of an extensional basin in the inner part of the orogen and delamination of the weak portion of the continental crust that is first thrusted toward the foreland and, subsequently, dissected by extensional tectonics. Transition from coupled to decoupled regime occurs always at the early stages of continental collision indicating that insertion of rheologically weak crustal material in the subduction channel is critical for the subsequent evolution of the collision zone. We found good correlations of our numerical results with some of the major collisional orogens. In particular, the decoupled retreating collision regime reproduces what is observed in the Northern Apennines. [Copyright &y& Elsevier]