1,720,996 research outputs found
Late Quaternary uplift and valley evolution in the Northern Apennines: Lamone catchment
No full textThe topographic evolution of mountain chains is fundamentally dictated by the balance of erosional and tectonic processes. In the Northern Apennines, several questions about the late Holocene to present deformation style and uplift rates are still open. We consider a typical NE facing drainage basin, focusing on all the geomorphic markers capable of supplying direct or indirect information regarding tectonic forcing on the landscape. Characteristics of altitude and relief, drainage pattern, river profile and fluvial response expressions were found to be in good agreement, indicating that the most recent tectonic activity consists of a general persistent uplift of the chain, associated with an extensional regime, where different sectors are distinguished through differential uplift. Such differences have been found to act both along and transverse to the chain, causing similar coherent patterns of response in erosional processes. The geomorphology of the catchment displays several features, which together with the long sustained tectonic forcing indicate the near-attainment of a dynamic equilibrium between the rates of tectonic forcing and erosional processes, creating steady-state topography. © 2002 Elsevier Science Ltd and INQUA. All rights reserved
Grandi colate nell’Appennino settentrionale.
No full textDato l’interesse per la loro diffusione, dimensioni e pericolosità, l’attenzione è stata rivolta alle frane delle Argille Scagliose, costituite in assoluta prevalenza da colate. Sono
state identificate, cartografate ed esaminate, dal punto di vista delle caratteristiche morfologiche, geometriche e di attività, alcune grandi colate ad ovest del T. Sillaro nell’Appennino bolognese ed in parte modenese, dove le Argille Scagliose affiorano su estensioni superiori al 50-60% dell’intero territorio montano
Geomorphological aspects, with environmental implications.
No full textThis chapter treats some applicational subjects) partly described in preceding chapters) with particular emphasis on geomorphological hazards due to both natural processes and human activities. The former essentially regard seismicity) subsidence) and fluvial and marine processes (flooding, beach erosion) storm surges). Risks due to antbropic activities are mainly linked to urban expansion) operations on watercourses and coastlines) quarrying, pumping of grounduiaters, and exploitation of hydrocarbon deposits
Structure and mineralogy of layer silicates: recent perspectives and new trends
No full textBecause of their many novel and advanced applications, there is increasing interest in layer silicates from the scientific and technical communities. Appropriate application of these minerals requires deep understanding of their properties and of the processes where they are involved. This chapter, by providing fundamental definitions and crystal structural and chemical data pertaining to layer silicates, aims to introduce this field to new researchers and technicians, by describing the fundamental features leading to different behaviours of layer silicates in different natural or technical processes. The subject addressed is vast and so the reader is referred in some cases to work already published. The focus here is on layer silicates for which detailed crystal structures are given in the literature and which are likely to be used in an applied way in the future. Layer-silicate minerals fulfilling these requirements are: (1) kaolin-serpentine group (e. g. kaolinite, dickite, nacrite, halloysite, hisingerite, odinite, lizardite, berthierine, amesite, cronstedtite, nepouite, kellyite, fraipontite, brindleyite, guidottiite, bementite, greenalite, caryopilite; minerals of the pyrosmalite series); (2) talc and pyrophyllite groups (e. g. pyrophyllite, ferripyrophyllite, willemseite); (3) mica group (i.e. some recent advances in crystal chemistry and structure of dioctahedral and trioctahedral micas); (4) smectite group (e. g. montmorillonite, saponite, hectorite, sauconite, stevensite, swinefordite); (5) vermiculite group; (6) chlorite group (e. g. trioctahedral chlorite such as clinochlore, di,trioctahedral and dioctahedral chlorites such as cookeite and sudoite); (7) some 2: 1 layer silicates involving a discontinuous octahedral sheet and a modulated tetrahedral sheet such as kalifersite, palygorskite and sepiolite; and (8) imogolite and allophane
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
Preliminary results from pore pressure monitoring on an unstable clay slope.
No full textWe monitored positive pore water pressure in a clay slope in the Apennines to investigate how rainfall influences the pore
pressure distribution along the soil profile and, consequently, affects slope stability conditions. Data refers to the first season of
monitoring activities (August 2001–June 2002). The study site is located at the head of a complex landslide, where incipient
shallow failures are visible along the slope.
The preliminary analysis of pressure data allowed to point out consistent trends, which manifested throughout 11 months.
During the cold and wet season, saturation always extends close to the ground surface ( < 1 m) and pore water pressure
measurements indicate a strong downward component of the flow, which is largely dominant over the downslope component, in
any condition. Response to rainfalls at shallow depth (1 to 3 m) generally consists in a pressure pulse whose delay is relatively
short if compared to low permeability of the soil and whose nature appears clearly transient. Although no failure occurred along
the slope during the observation period, it is very likely such transient response would mimic the pore water pressure pattern
capable to cause sliding.
The presence of prefertial flow path in the sub-surface can only explain anomalous response of some sensors or substantial
differences between buried at similar depths
Monitoraggio delle pressioni interstiziali in un versante argilloso in frana
No full textLa frana di Ca’ di Malta, localizzata nell’Appennino settentrionale, a circa 30 km a sud di Bologna, nella Valle del
Fiume Reno, nei pressi del centro abitato di Vergato, per i suoi lenti cinematismi e per il volume limitato di materiale
coinvolto nel franamento, non costituisce un fenomeno a rischio molto elevato, secondo i canoni della L. 267/98,
ma si presta molto bene allo studio di dettaglio dei meccanismi che regolano il franamento di argilloscisti fessurati.
I campi di sperimentazione affrontati in questo caso sono il rilevamento topografico con tecniche innovative, il
monitoraggio delle pressioni interstiziali nei materiali alterati di superficie e nel substrato, nonché alcune proposte
di interventi di stabilizzazione
- …
