1,720,970 research outputs found
3. Lo studio della pianura
No full textIl capitolo si suddivide in 3 paragrafi: 3.1 - Il rilevamento geologico e pedologico (a cura di A. Amorosi e M. Guermandi); 3.2 - La stratigrafia del sottosuolo (a cura di A. Amorosi); 3.3 - La cartografia geologica e pedologica (a cura di A. Amorosi e M. Guermandi
Nitrate leaching through the unsaturated zone following pig slurry applications
No full textAs the increase of nitrate concentration in groundwater has often been ascribed to an inappropriate use of liquid manure, the main purpose of this study was to better understand the factors controlling nitrate dynamics in the unsaturated zone of soils subjected to characteristic agronomic practices, and to contribute to improving Action Programmes, with reference to EU
Directive 91/676, for nitrate vulnerable zones (NVZ).
Water infiltration and nitrate leaching have been studied in experimental fields located inside nitrate vulnerable zones of the Emilia-Romagna region (Northern Italy), characterized by different pedological and hydrogeological properties and equipped with meteorological station, tensiometers, ceramic-cup samplers and piezometers. This article describes the
results obtained from one of these sites, monitored over a 6-year period, which was cereal cropped and treated with pig slurry. MACRO and SOILN field-scale models have been used in order to verify the reliability of simulated water flow and nitrogen transport.
The results demonstrate how nitrogen inputs from slurry, substantially higher than crop uptake, cause nitrate accumulation in the surface layer of the soil especially in warm periods (concentrations of up to 300 mg NO3–N lK1 were found in soil water).
Even if the soil texture was fine, the shrinking–swelling properties of clay minerals determined fast drainage conditions (related to macroporosity), so that during the early rainy periods nitrates leached through the first meters of the unsaturated zone, at least
down to 4 m. This shows that nitrate accumulation should be limited before these periods, i.e. by reducing manure application rates, especially if the soil is to be left uncultivated
The pedogeochemical map as a support for environment planning strategies in Emilia-Romagna
No full textA reliable evaluation of metal contents in soils, under both natural and anthropogenic conditions, is a fundamental issue. In this work, we show our methodology applied to the case study of the western Emilia-Romagna plain in determining the pedogeochemical contents of heavy metals and their anomalies. In this context, where natural values of some metals (Cr and Ni) for several soil types exceed the threshold limits indicated by the law, the application of an adequate methodology in geochemical anomalies evaluation assumes a significant role
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
CONFRONTO TRA DIVERSE MISURE DI LABORATORIO DELLA CURVA DI RITENZIONE IDRICA DEI SUOLI PER IL MIGLIORAMENTO DELLA STIMA DEL BILANCIO IDRICO IN EMILIA ROMAGNA
No full textLa curva di ritenzione idrica dei suoli è una proprietà di fondamentale importanza che mette in relazione il potenziale dell’acqua nel suolo ed il suo contenuto idrico. Essa influenza un vastissimo numero di processi quali la germinazione dei semi e la disponibilità idrica per le piante, i flussi idrici nel suolo, l’attività microbica e quindi la degradazione della sostanza organica, l’evaporazione, i flussi di soluti ed in generale il bilancio idrico. Le piastre a pressione (anche chiamate piastre di Richards) sono tra gli strumenti di laboratorio più comuni per la determinazione
della curva di ritenzione idrica. Negli ultimi anni, numerose ricerche hanno messo in luce i limiti sperimentali e gli errori introdotti dall’utilizzo delle piastre di Richards, in particolare a valori intermedi e molto negativi di potenziale idrico. Si presenta qui un confronto tra due diversi metodi di misura per la curva di ritenzione idrica, le piastre di Richards e il metodo a punto di rugiada, per due suoli dell’Emilia Romagna. Lo studio ha il fine di migliorare la qualità della misura e quindi la stima del bilancio idrico, che necessita di precise parametrizzazioni delle funzioni idrologiche del suolo.La curva di ritenzione idrica dei suoli è una proprietà di fondamentale importanza che mette in relazione il potenziale dell’acqua nel suolo ed il suo contenuto idrico. Essa influenza un vastissimo numero di processi quali la germinazione dei semi e la disponibilità idrica per le piante, i flussi idrici nel suolo, l’attività microbica e quindi la
degradazione della sostanza organica, l’evaporazione, i flussi di soluti ed in generale il bilancio idrico. Le piastre a pressione (anche chiamate piastre di Richards) sono tra gli strumenti di laboratorio più comuni per la determinazione della curva di ritenzione idrica. Negli ultimi anni, numerose ricerche hanno messo in luce i limiti sperimentali e gli errori introdotti dall’utilizzo delle piastre di Richards, in particolare a valori intermedi e molto negativi di potenziale idrico. Si presenta qui un confronto tra due diversi metodi di misura per la curva di ritenzione idrica, le piastre di
Richards e il metodo a punto di rugiada, per due suoli dell’Emilia Romagna. Lo studio ha il fine di migliorare la qualità della misura e quindi la stima del bilancio idrico, che necessita di precise parametrizzazioni delle funzioni idrologiche del suolo
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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