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Un approccio micromorfologico per lo studio dei processi di degradazione dei suoli in contesto agropastorale
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Catalytic removal of methane over thermal-proof nanostructured catalysts for CNG engines
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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
Il ruolo della pedofauna nella variabilità spaziale e temporale delle forme di humus: indagini micromorfologiche su sezioni sottili ed osservazioni allo stereoscopio
No full textL'osservazione allo stereoscopio dei campioni di orizzonti diagnostici di diverse forme di humus permette di distinguere l'origine biologica di queste e di riconoscere i grandi gruppi di animali coinvolti nel processo di trasformazione della lettiera e della sua integrazione nel profilo del suolo.
- - - - - (ABSTRACT: In a spruce forest of the Autonomous Province of Trento, located on an acid substrate and with a north exposition, within the Village of Pellizzano, a transect has been traced; along this transect 19 humus profiles have been examined, one at every three meters. For each of them, OH and A horizons (respectively the humic organic and the organo-mineral horizon) have been sampled and studied following the methodology formulated by Ponge (1984) and Bernier et al. (1994). The morphological and semi-quantitative observation of these horizons with the stereoscope and the use of an identification key of soil fauna’s faecal pellets (Galvan et al. 2005) allowed us to determine and point out their relative abundance and to formulate interesting remarks on spatial and temporal variability of humus forms in forests. For four profiles of the transect, a micro-morphological study, with the microscope, of the thin sections of every horizon has been carried out as well, in order to observe those more detailed characters such as: the presence of fossilized coprolites, of paleo-aggregates and of those soil fauna’s dung, in particular mites’ faecal pellets, hardly identifiable with the stereoscope. Both methodology of morphological investigation proved to be necessary for an accurate research and to be a substantial aid for a better identification of humus forms, after they have been described in field following the French morphological-genetic approach (Jabiol et al. 1995)
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