1,720,979 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Double-Skin Façades for Building Retrofitting and Climate Change: A Case Study in Central Italy
Full text linkIn recent years, the need to make the built environment more resilient and adaptable to climate change has become essential. In Europe, this aspect concerns most existing buildings with several deficiencies from the energy efficiency point of view, considering they were designed before the introduction of modern codes. Among the various strategies for building energy retrofitting, Double-Skin Façades (DSFs) have gained attention due to their potential to improve the building performance and inhabitants’ comfort. This research aims to evaluate the use of adequately designed DSFs for the energy restoration of buildings. In detail, various DSF configurations are applied to a residential building located in Central Italy and investigated under present and future climate conditions, estimated through regional climate models. The installation of multi-layered façades, particularly the Multi-Storey typology, greatly reduces energy consumption and increases the expected comfort rates. When the selected configuration was considered, the results underline a decrease in the annual building energy requirement of about 37–56% up to 42–59%, respectively, for 2030 and 2070. Moreover, using multi-layer façades can increase indoor minimum operative temperatures up to 3.8% during the coldest months and reduce the maximum summer ones by 1.9–3.8%, raising comfort levels
Naturally Ventilated Double Skin Façades: Comparisons Between Different CFD Models
No full textDouble Skin Façades (DSFs) have become widespread solutions commonly employed in new and existing buildings in the last decades. Since its introduction, the multilayered façade has improved profoundly, assuming more articulate and complex shapes for better energy performances and combining advanced technologies as innovative materials or systems. However, the effectiveness and the thermal behaviour of DSFs should be carefully evaluated since the design phase by selecting proper methodologies, thus avoiding inaccurate results. In fact, the correct estimation of the airflows inside DSF channels is heavily influenced by the simulation settings. Furthermore, the lack of measurements or empirical validations in the field is the primary source of concern for researchers. Considering the available numerical methods for investigating DSFs, Computational Fluid Dynamics (CFD) simulations have proven to be the most appropriate option. The present work compares multiple Double Skin Façade configurations by performing CFD analyses and adopting different turbulence models in bi and three-dimensional domains. The results underline the capability of 2D models in predicting the fluxes inside the DSF channel and in the domain. Furthermore, comparisons among the velocity profiles estimated by adopting different turbulence formulations highlight only slight variations, especially in proximity to the perturbated areas of the cavit
Atti dei Corsi di Aggiornamento per docenti della Scuola Secondaria di Secondo Grado anni 2006 e 2007. Facoltà di Scienze Mat. Fis. e Nat. Università Roma Tre - CD-ROM
No full textChurches Acoustics as Intangible Cultural Heritage: Experimental and Numerical Characterization of the Temple of San Biagio
Full text linkThe acoustic properties of churches are, to date, as much a cultural asset as their architectural features. The study, understanding and conservation of acoustic phenomena that characterize liturgical spaces, to date, make use of new technologies and methodologies that facilitate their practice. The study presented here analyzes the acoustic phenomena that characterize the Temple of San Biagio (Montepulciano, Tuscany, Italy). It makes use of experimental acoustic surveying and the aid of the laser scanning surveying technique for the creation of the geometry, subsequently adopted for numerical acoustic modeling of the church in Odeon Acoustics software, used for the study of its acoustic characteristics. The selected methodology allowed us to delve into dynamics often encountered in acoustic simulations, such as the calibration of numerical models and the influence of the mesh number of the generated geometric models, and to understand the acoustic characteristics of the church
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
A Mesoscale-Microscale approach for the energy analysis of buildings
Full text linkThis work is aimed to suggest a numerical approach able to select the most useful building orientation with respect to the local wind in complex urban areas. It is showed a mesoscale-microscale numerical approach able to predict local flow patterns for building designers. The city of Ancona was selected to analyse wind patterns over complex orography in presence of buildings. The analysed area is characterized by a densely built hilly promontory flanked by a poorly urbanized valley. Two buildings were chosen to carry out energy analyses. At first, the MM5 weather prediction model is used to assess the wind patterns and the wind occurrence distribution. The 2010 year was simulated and compared with real data from a met-mast. After, computational fluid dynamic (CFD) analyses are conducted with and without the surrounding buildings to appreciate speed and inflow e ̇ects. CFD results showed great changes in the examined building area. The final step was the energy simulation, by means of EnergyPlus, of two multistoried buildings equipped with a double skin façade; results show a great impact on the energy consumption by comparing a wrong orientation with respect to the best solution derived from the mesoscale-microscale approach
Towards DES/DDES computation of the flow field and heat transfer adopting elliptic relaxation and local correlation based transition approaches
No full textAs Large-Eddy Simulation (LES) shall remain too expensive in the following few decades for the ever increasing number of engineering complexities, researches have shifted much of the attention and effort to hybrid formulations incorporating Reynolds-Averaged Navier- Stokes (RANS) equations and LES in a certain ways. The long term goal of this research activity is to develop accurate hybrid RANS/LES methods. These approaches are particularly appealing in massively separated flows since they offer good prediction performance and they can be considered a good trade-off, in terms of computational resources, if compared with standard LES techniques. In particular with this work we want to deeply investigate Detached-Eddy Simulation (DES) based on: (i) elliptic relaxation turbulence model; (ii) Spalart Allmaras local correlation based transition model (LCTM). Specifically, we analyze v2-f DES approach for the convective heat transfer around a sphere at Re = 5000 (with Pr = 0.71) and we compare these results with the so called delayed version of the model. At the same time we also investigate the LCTM version of the SA model, in the DES context
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