1,721,345 research outputs found
Analysis of the Air Pollution Sources in the city of Rome (Italy)
Full text linkPollution depends on many natural and human factors. The variation of pollutant and weather changes modify the concentration of pollutant in time and space. In fact, this is not only a local problem, but a regional and even global influence is highlighted. People who moved from the countryside to the cities made the air condition worse, because of the factories activities and the domestic heating. These kinds of pollutants, together with the ones related to the urban traffic, are the base of the air toxicity, which can lead to a lot of health problems. Apart from people, even monuments and works of art can be damaged by pollution, especially in the city centres. Exposure to pollutants is usually higher in cities than in the countryside. The more common pollutants produced at high density urban areas are carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx), ozone (O3), particulate matter (PM) and benzene (C6H6). The aim of this work is to study the air pollutant level in the city of Rome in order to analyse the emissions from di-erent sources. Furthermore, the pollutant exceeds of the limit of the Directive 2008/50/EC, the main legislation about ambient air quality, was analysed for the period taken into account
Analysis of Convective Heat Transfer at Building Facades in Street Canyons
No full textThe natural convection effects on the flow structures and the heat processes have been analysed in an urban canyon. Predictions of convective heat transfer are essential in building and environmental studies on urban heat islands and building energy performance. An important part of the heat exchange between buildings and the ambient surrounding is due to convective and radiative heat flows. An idealized 2D urban canyon with Height/Width (H/W) equal to 1 were evaluated. The aim of this study is to quantify the influence of different wind intensity to the convective heat transfer coefficient when the walls were heated
Numerical Study of Buoyant Flows in Street Canyon Caused by Ground and Building Heating
Full text linkThe urban areas discomfort is related to the increase of local temperatures, which is induced by the large concentration of the built environment, road pavement and the high construction materials thermal capacitance. The particular configuration of buildings arrangement amplifies the population vulnerability and the exposure to pollution. These conditions can be related to the "urban fabric" density, road geometrical characteristics, buildings features and, finally, to the lack of wide-open spaces. An important part of the heat exchange between buildings and the ambient surrounding is due to convective and radiative phenomena. Computational fluid dynamics (CFD) is often used to predict flow structures in urban areas for the determination of pollutant dispersion, human comfort or heat fluxes. During daytime building façades and ground surfaces are heated by solar radiation and thereby they induce buoyancy, which changes the flow field around buildings significantly. A computational fluid dynamics (CFD) model is developed and used to investigate the thermo-fluid dynamic effects inside and above a street canyon. In this study different simulations have been performed and validated, investigating the micro-climatic condition, such as thermal and air velocity fields
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
Using Cool Pavements to Mitigate Urban Temperatures in a Case Study of Rome (Italy)
No full textThe urban density and the design of built and natural environments of cities play a crucial role in defining sustainable patterns. Urban heat islands (UHI) are phenomena tightly associated with the development of cities and urban expansion. Its effect is defined as the increase of the urban air temperature compared to surrounding rural areas. One of the main technology aimed at reducing the urban air temperature is the adoption of cool materials. As a matter of fact, the increasing of solar reflectance of urban materials can lead to reduce the built surface temperatures and mitigate the urban heat island intensity. Its features have vast impacts and implications on energy efficiency, environment and at last on human comfort and health. Measured temperatures were used to calibrate a model of a densely populated neighborhood in Rome inputted in ENVI-met software. The actual temperature field was evaluated in comparison with proposed areas consisting in the adoption of high albedo pavements application. Simulation results showed a significant reduction of air temperature closely correlated with the road solar reflectance
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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