1,720,976 research outputs found
Dal fronte della lotta antigradine: ‹cartoline› trentine, 1949-1981
No full textLa difesa attiva o “lotta” contro la grandine ha antiche origini e ancora oggi si confonde spesso con credenze popolari. In questo articolo si racconta l’epopea dei razzi esplodenti quale mezzo di “lotta alla grandine” in Trentino e in Italia, una tecnica che iniziò a diffondersi appena dopo la fine della Seconda Guerra mondiale, sotto la spinta delle aspettative, degli entusiasmi contagiosi e di metodi di validazione dal significato (oggi) dubbio, che si avvalevano di conoscenze ancora parziali e non ben consolidate. Nei decenni centrali del secolo scorso i razzi esplodenti furono al centro di uno sforzo “bellico” distribuito in tutta Italia, documentato da relazioni periodiche e da uno speciale registro di ciascun evento meteorologico: le “cartoline dei temporali”. Tali cartoline venivano compilate per ogni evento temporalesco dalla fine del 1800 fino agli anni 1970; in alcuni formati veniva annotato anche l’effetto “osservato” delle misure antigrandine. Agli occhi di chi oggi rilegge le vicende, si evidenzia un disallineamento non chiaro ai protagonisti di allora: le cartoline dovevano servire come banca dati per validare l’efficacia dei razzi esplodenti, ma le basi scientifiche del loro presunto effetto erano già state messe in discussione 50 anni prima.Attraverso la lettura di 1650 cartoline dei temporali, provenienti da 117 località della provincia di Trento, raccolte presso l’archivio meteorologico storico del CREA1, recentemente organizzato nel corso del progetto ASTRO2, si racconta, nella sua cronologia, la diffusione e il successivo abbandono dei razzi esplodenti come mezzo di difesa attiva. L’infondatezza del funzionamento dei razzirisulta evidente anche da alcuni elementi scientifici riportati, che prendono in coinsiderazione anche altre “armi” di lotta alla grandine. In fondo, l’epopea dei razzi esplodenti è la storia di un errore sistematico di valutazione, tutt’oggi diffuso in molti ambiti, noto in psicologia come “bias di conferma”, in cui le persone tendono a selezionare (a vedere solo) gli elementi a favore di una data spiegazione e a screditare i fatti contrari. Ancora oggi, ritornano proposte commerciali di “moderni” mezzi esplodenti contro la grandine di “sicura” efficacia
Impact of Cool Materials on Ambient Temperatures in an Urban Area
No full textThe urban heat island is a problem that affects our cities and results in a warmer climate in the urban and residential areas compared to the surrounding rural areas. One solution to this problem involves the use of materials with high solar reflectance and high thermal emissivity, the so-called “Cool Materials”. Their surface temperatures are much lower than those of typical building materials. Usually Cool Materials are used to decrease heat flow entering in a building, but if used on an urban scale, their lower surface temperature lead to a lower heat exchange between air and surfaces, helping to decrease the air temperature of the urban environment. The paper reports the results of a study carried out on a densely populated area in Rome of about 500.000 m2. The study was divided into three parts. The first part involves the comparison and the analysis of data collected by weather stations of airports and public agencies located both in urban areas and in peripheral areas in order to monitor the magnitude of the heat island effect. The second part includes measurements of the thermal properties of some Cool asphalts. The third part is focused on numerical analysis of the phenomenon through the creation of a model included in a S.V.A.T. software that allows to compare the outdoor air temperature of an area before and after a hypothetical use of Cool Materials on external surfaces of buildings and street pavements. The results of this study demonstrated the significant influence of cool materials on the reduction of the heat island phenomenon
Impact of Cool Materials on Ambient Temperatures in an Urban Area
No full textThe urban heat island is a problem that affects our cities and results in a warmer climate in the urban and residential areas compared to the surrounding rural areas. One solution to this problem involves the use of materials with high solar reflectance and high thermal emissivity, the so-called “Cool Materials”. Their surface temperatures are much lower than those of typical building materials. Usually Cool Materials are used to decrease heat flow entering in a building, but if used on an urban scale, their lower surface temperature lead to a lower heat exchange between air and surfaces, helping to decrease the air temperature of the urban environment. The paper reports the results of a study carried out on a densely populated area in Rome of about 500.000 m2. The study was divided into three parts. The first part involves the comparison and the analysis of data collected by weather stations of airports and public agencies located both in urban areas and in peripheral areas in order to monitor the magnitude of the heat island effect. The second part includes measurements of the thermal properties of some Cool asphalts. The third part is focused on numerical analysis of the phenomenon through the creation of a model included in a S.V.A.T. software that allows to compare the outdoor air temperature of an area before and after a hypothetical use of Cool Materials on external surfaces of buildings and street pavements. The results of this study demonstrated the significant influence of cool materials on the reduction of the heat island phenomenon
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
