1,720,960 research outputs found
Atlante geochimico-ambientale dei suoli e dei sedimenti fluviali della Basilicata
No full textNel presente atlante geochimico-ambientale sono illustrati i risultati ottenuti dalle indagini eseguite sull’intero territorio della Regione Basilicata, dove è stata effettuata una campionatura ex novo di sedimenti fluviali. Su una superficie di 9.992 Km2 sono stati raccolti, con una densità nominale di circa 1 campione per 10 km2, 801campioni, analizzati con una metodologia analitica che combina l’ICP-MS (spettrometria di massa al plasma accoppiato induttivamente) e l’ICP-ES (spettrometria ad emissione al plasma accoppiato induttivamente) per la determinazione delle concentrazioni di 39 elementi chimici. Le carte geochimico-ambientali che compongono questo atlante rappresentano una “fotografia” dell’attuale distribuzione delle concentrazioni degli elementi chimici analizzati nei sedimenti fluviali e potranno essere utilizzate in futuro come riferimento per la valutazione dell’impatto ambientale delle attività antropiche presenti nella Regione. Nello specifico, questo atlante raccoglie: le carte geochimiche (puntuali e interpolate) delle concentrazioni di 38 elementi chimici analizzati nei sedimenti fluviali: Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sc, Se, Sn, Sr, Te, Th, Ti, Tl, U, V, Zn; le carte geochimiche dei valori background degli stessi 38 elementi; le carte geochimiche (puntuali e interpolate) dei factor scores delle 4 associazioni fattoriali, scaturite dall’analisi fattoriale in R-mode
Geochemical and Pb isotopic characterization of soil, groundwater, human hair, and corn samples from the Domizio Flegreo and Agro Aversano area (Campania region, Italy)
No full textA geochemical survey was carried out to investigate metal contamination in the Domizio Littoral and Agro Aversano area (Southern Italy) by means of soil, groundwater, human hair and corn samples. Pb isotope ratios were also determined to identify the sources of metals. Specifically, the investigation focused on topsoils (n = 1064), groundwater (n = 26), 25 human hair (n = 24) and corn samples (n = 13). Topsoils have been sampled and analysed in a previous study for 53 elements (including potentially harmful ones), and determined by ICP-MS after dissolving with aqua regia. Groundwater was analysed for 72 elements by ICP-MS and by ICP-ES. Samples of human hair were prepared and analysed for 16 elements by ICP-MS. Dried corn collected at several farms were also analysed for 53 elements by ICP-MS. The isotopic ratios of 206Pb/207Pb and 208Pb/207Pb in selected topsoil (n = 24), groundwater (n = 9), human hair (n = 9) and corn (n = 4) samples were analysed from both eluates and residues to investigate possible anthropogenic contamination and geogenic contributions. All data were processed and mapped by ArcGis software to produce interpolated maps and contamination factor maps of potentially harmful elements, in accordance with Italian Environmental Law (Legislative Decree 152/06). Results show that soil sampling sites are characterized by As, Cd, Co, Cr, Cu, Hg, Pb, Se, and Zn contents exceeding the action limits established for residential land use (RAL) and, in some cases, also the action limits for industrial land use (IAL) as established by Legislative Decree 152/06. A map of contamination factors and a map showing the degrees of contamination indicate that the areas in the municipalities of Acerra, Casoria and Giugliano have been affected by considerable anthropogenic-related pollution. To interpret the isotopic data and roughly estimate proportion of Pb from an anthropogenic source we broadly defined possible natural and anthropogenic Pb end-member fields based on literature data. For example, we summarized data for Vesuvius and Campi Flegrei volcanic rocks, gasoline, and aerosol deposits.
Lead isotope data show mixing between geogenic and anthropogenic sources. Topsoil, groundwater, human hair and corn samples show a greater contribution from geogenic sources like the Yellow Tuff (from Campi Flegrei) and volcanic rocks from Mt. Vesuvius. Aerosols, fly ash and gasoline (anthropogenic sources) have also been contributors. In detail, 46% of the topsoil residues, 96% of topsoil leachates, 88% of groundwater, 90% of human hair, and 25% of corn samples indicate that > 50% percent of the lead in this area can be ascribed to anthropogenic activity
Geochemical characterization, isotopic approach and environmental risk assessment in the Domizio Flegreo and Agro Aversano area (Campania region)
No full textAtlante geochimico–ambientale dei suoli della Campania
No full textL’Atlante illustra i risultati ottenuti dalle indagini sui suoli superficiali della Campania. Su un’area di 13.595 Km2 sono stati raccolti 3.535 campioni di suolo e analizzati con una metodologia che combina l’ICP–MS (Spettrometria di massa al plasma accoppiato induttivamente) e l’ICP–ES (Spettrometria a emissione al plasma accoppiato induttivamente). Per ogni elemento chimico sono riportate le proprietà, le applicazioni, gli effetti sulla salute, nonché la distribuzione geochimica in Campania. Le carte geochimico–ambientali che compongono il volume rappresentano una “fotografia” risalente al momento del campionamento e potranno essere utilizzate in futuro come riferimento per la valutazione dell’impatto ambientale delle attività antropiche presenti sul territorio. Sono anche uno strumento di notevole valenza ambientale, soprattutto per quanto concerne la valutazione dei tenori di fondo (background) dei vari elementi chimici esaminati
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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