1,721,225 research outputs found
EFFECTS OF ENERGETIC SOLAR PARTICLES ON OZONE AND MINOR ATMOSPHERIC COMPONENTS INSIDE THE POLAR REGIONS
No full textSolar activity influences the Earth’s environment, in particular the atmospheric
ozone, by the direct output of the e.m. radiation or through the variability of the
incoming cosmic ray flux (solar and galactic particles). Especially energetic particles,
arising from huge explosions on the Sun’s surface, travel in the interplanetary
medium and, if the circumstances were favorable, they could enter the terrestrial
atmosphere (driven by the geomagnetic field lines of our planet) and reach the polar
cap regions (geomagnetic latitude > 60°). There, they provide additional external
energy and are able to produce ionizations, dissociations, dissociative ionizations
and excitations phenomena by interacting with the minor constituents. The induced
changes are not confined to the ion chemistry but also to the neutral components. In
this way a rise of the concentration of HOx and NOx species and the triggering of
catalytic cycles which lead to short (hours) and medium (days) term ozone
destruction occur. Finally, also no-reactive reservoir species (e.g., HNO3, HCl, HOCl)
are involved in these processes and endure large variations.
The present thesis highlights the chemical variability of the middle atmosphere
during and after some Solar Energetic Particle (SEP) events recorded during the
current solar cycle. Special attention has been paid to the relationship between
ozone and HOx data (retrieved from the Microwave Limb Sounder of EOS AURA
satellite) for four events referred to 2005. The HOx data, recorded for the first time
during the intense ionization caused by the SEP flux, have pointed out some features
related to these phenomena not wholly captured by the current theoretical models. In
addition, they have highlighted that the HOx rise is able to destroy the so-called third
ozone peak at the polar latitudes of the winter hemisphere and it occurs also during
medium intensity events. Besides, the analyses of January 2005 SEP events have
shown that the changes on the hydrogen species leaded to variability in the
concentration and partitioning of chlorine family, not discernible in the summer
hemisphere. Further, the use of data coming from the HALOE instrument, referred to
SEP events occurred in July 2000 and April 2002, has in short confirmed past
experimental results. Finally, the study of a little SEP event occurred during May 2003
has pointed out that SEP events are not the unique ionization source inside the polar
latitudes during the winter.INAF-IFSI, CNR-ICESPublished1.7. Osservazioni di alta e media atmosferaope
La natura giuridica dei contratti di finanza etica
No full textI contratti di finanza etica rappresentano un fenomeno contrattuale nato nella prassi bancaria consistente in tutte quelle operazioni finanziarie in cui un soggetto privato, persona fisica o giuridica, stipula contratti con una banca regolamentando il rapporto in maniera da realizzare attribuzioni ad enti o organizzazioni non profit ovvero condizionando la Banca a finanziare alcuni settori con l’obbligo di non utilizzare le somme corrisposte dal cliente in maniera diversa da quanto pattuito.
Si è visto altresì che esistono tre categorie di contratti di finanza etica per ciascuna delle quali ne viene analizzata la natura giuridica. Si tenta di capire altresì se i contratti di finanza etica sono caratterizzati da una causa specifica loro propria. A tal proposito viene esaminata quella tesi dottrinale finalizzata a distinguere la causa donativa dalla causa di solidarietà sull’assunto che la solidarietà rappresenta un valore base dell’ordinamento giuridico. Dopo attenta disamina si conclude che il tipo donazione si presenta sufficientemente ampio da racchiudere nel suo ambito gran parte delle ipotesi negoziali connotate dall’assenza di obblighi, giuridici o morali, che impongono al soggetto agente il compimento dell’atto. Si potrà dunque far riferimento al contratto di donazione senza configurare una causa di solidarietà posto che le attribuzioni ad enti non profit non sono altro che donazioni realizzate mediante mandati conferiti alla Banca presso la quale si intrattiene il rapporto etico
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
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