1,721,077 research outputs found
The optimal design for stacks of parallel rectangular fin cooled by forced convection
No full textSwieradow Zdroj - Polan
Climate Models for the Assessment of Office Building Energy Performance
No full textIn the last few years many advanced computer packages, characterised by a considerable integration between thermal and visual aspects, were developed to support designers and to study building energy performance, innovative materials and daylight control strategies and systems. These packages, as a function of their complexity and use, require different types of outdoor data, ranging from monthly (MTD) or seasonal typical days (STD) to more complex typical meteorological years (TMY). Both the deterministic and the stochastic components of outdoor data are present in TMYs, while MTDs and STDs take into account only the deterministic component. The use of MTDs or STDs produces a sensible reduction of the calculation time, above all appreciable in the first phase of the building design process, although it introduces an element of uncertainty in simulation results due to the absence of the stochastic component of outdoor data. This uncertainty is not easily predictable, as reported by many authors. The aim of the present work is to investigate the influence of the stochastic component of meteorological data in evaluating building energy performance in Mediterranean climate. The study is performed by an advanced numerical computer package, Integrated ENergy Use Simulation (IENUS), which can process different types of climatic data. Different typologies, systems and space managements are investigated
Electrochromic Windows as a Chance to Improve Energy Saving in Office Buildings in Mild Climate
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Assessment of outdoor thermal comfort and its relation to urban geometry
No full textMicroclimate conditions in urban open spaces are directly linked to the configuration of street axes and building heights and their attributes. Within street canyons, public places, and open spaces, the local microclimate depends directly on the physical properties of the surrounding surfaces and objects, producing well-known effects that can decrease or increase thermal loads. All of these phenomena can greatly influence the comfort of a city and the thermal comfort of pedestrians. Thermal comfort is an indicator that cannot be easily converted into physical parameters. However, it may be defined more qualitatively as the range of climatic conditions in which most people feel comfortable. One well-recognized thermal comfort index used to measure comfort levels inside a space is the predicted mean vote (PMV). Fanger's PMV index has been widely used in the last ten years. It is based on six factors: air temperature, air speed, humidity, mean radiant temperature, metabolic rate, and clothing levels. The comfort equation establishes relationships among the abovementioned environmental variables, clothing type, and metabolic rate. The authors present results of PMV simulations using a multi-objective optimization tool (i.e., modeFrontier). ModeFRONTIER is an integration platform used to optimize and arrange PMV algorithms linked to urban geometry parameters (e.g., the height-to-width (H/W) ratio of urban streets). The optimization process employs given constraints, custom procedural algorithms, and genetic algorithms to examine a wide urban space and identify interesting relationships among the variables considered. Urban geometry, meteorological data, and latent influences are examined and negotiated quantitatively to improve outdoor thermal comfort. © 2013 WIT Press
On the Interplay between Desert Dust and Meteorology Based on WRF-Chem Simulations and Remote Sensing Observations in the Mediterranean Basin Rizza, U.; Avolio, E.; Morichetti, M.; Di Liberto, L.; Bellini, A.; Barnaba, F.; Virgili, S.; Passerini, G.; Mancinelli, E.
No full textIn this study, we investigate a series of Saharan dust outbreaks toward the Mediterranean basin that occurred in late June 2021. In particular, we analyze the effect of mineral dust aerosols on radiation and cloud properties (direct, semi-direct and indirect effects), and in turn, on meteorological parameters. This is achieved by running the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) over a domain covering North Africa and the Central Mediterranean Basin. The simulations were configured using a gradual coupling strategy between the GOCART aerosol model and the Goddard radiation and microphysics schemes available in the WRF-Chem package. A preliminary evaluation of the model performances was conducted in order to verify its capability to correctly reproduce the amount of mineral dust loaded into the atmosphere within the spatial domain considered. To this purpose, we used a suite of experimental data from ground- and space-based remote sensing measurements. This comparison highlighted a model over-estimation of aerosol optical properties to the order of 20%. The evaluation of the desert dust impact on the radiation budget, achieved by comparing the uncoupled and the fully coupled (aerosol–radiation–clouds) simulation, shows that mineral dust induces a net (shortwave–longwave) cooling effect to the order of −10 W m−2. If we consider the net dust radiative forcing, the presence of dust particles induces a small cooling effect at the top of the atmosphere (−1.2 W m−2) and a stronger cooling at the surface (−14.2 W m−2). At the same time, analysis of the perturbation on the surface energy budget yields a reduction of −7 W m−2 when considering the FULL-coupled simulation, a positive perturbation of +3 W m−2 when only considering microphysics coupling and −10.4 W m−2 when only considering radiation coupling. This last result indicates a sort of “superposition” of direct, indirect and semi-direct effects of dust on the radiation budget. This study shows that the presence of dust aerosols significantly influences radiative and cloud properties and specifically the surface energy budget. This suggests (i) that dust effects should be considered in climate models in order to increase the accuracy of climate predictions over the Mediterranean region and (ii) the necessity of performing fully coupled simulations including aerosols and their effects on meteorology at a regional scale
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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