1,720,960 research outputs found
Softening and swelling mechanism affecting south slope of Civita di Bagnoregio (VT)
No full textCivita di Bagnoregio is a small village in Central Italy, located on the top of a hill and affected by landslides that are progressively reducing the urban area. The access consists of a pedestrian bridge that connects Bagnoregio municipality to the village. The south slope beneath the bridge, is involved by frequent instability phenomena. This work describes the analysis carried out and it aimed at the definitions of geological and geotechnical mechanism affecting the above mentioned slope. A geotechnical survey has been carried out. These surveys showed the presence of a superficial layer, resulting from the softening and swelling of underlying clay-silty strongly overconsolidated, responsible for the superficial landslide phenomena. A slope stability and a 3D laser scanner model has been carried out. The analysis demonstrates that a correct design for the landscape preservation and consolidation of unstable towns needs an understanding of triggering mechanism and geotechnical properties of the involved soils. © 2013 Taylor & Francis Group, London
Il permeametro di Boutwell
No full textLa caratterizzazione e la qualifica delle barriere
argillose avviene attraverso uno studio
articolato che ha come principale obiettivo
la determinazione della conducibilità idraulica,
o coefficiente di permeabilità k. Tale grandezza,
che esprime l’attitudine di un mezzo ad essere
attraversato da un fluido, è misurata sia mediante
prove di laboratorio su provini di piccole dimensioni
estratti dalle barriere che per mezzo di prove
eseguite direttamente sul manto. L’esperienza ha
dimostrato come la conducibilità ottenuta da prove
in sito sia un parametro di collaudo più affidabile
rispetto al dato ricavato in laboratorio in quanto,
interessando volumi maggiori di terreno, permette
di verificare direttamente la macrostruttura della
barriera realizzata. Tale considerazione, di validità
generale, ha un risalto particolarmente importante
nei manti argillosi artificiali in quanto la tecnica
di realizzazione mediante compattazione per strati
può determinare una significativa anisotropia della
barriera in direzione prevalentemente orizzontale.
Tra tutti i metodi di prova in sito (infiltrometri
semplici e doppi, lisimetri, permeametri vari, ecc.)
il Double Stage Boutwell Permeameter (TSB) è l’unico che permette di misurare separatamente
le due componenti della conducibilità idraulica,
verticale ed orizzontale, e quindi risulta il più
idoneo ad essere applicato a barriere multistrato.
La maggior parte dei metodi di prova in sito, a differenza
della prova TSB, indagano prevalentemente
la filtrazione in direzione verticale e forniscono
indicazioni incomplete o meglio non cautelative
nella progettazione dei manti. La prova TSB ha
come standard di riferimento la norma ASTM
D6391Clay liners or covers are an important components
of waste retention structures, are used as impervious
fluid containment barriers for the horizontal transport
of process fluids or the containment of pollutants for
the protection of groundwater resources from the
development of leachate that could migrate downward.
The most important geotechnical parameter for
compacted clay is hydraulic conductivity which
governs the barrier effect. Experience has show that
field hydraulic conductivities may be substantially larger
than those measured on small laboratory specimens.
Many different in situ tests have been proposed, of
these the Sealed, Double Ring Infiltrometer (SDRI)
and Two Stage Borehole (TSB) test have received
widest acceptance and use. The TSB method involves
three dimensional infiltration, from which both vertical
and horizontal conductivities are determined. These
hydraulic conductivity values are the maximum possible
for the vertical direction and minimum possible for the
horizontal direction. This test method may be utilized for compacted
fills or natural deposits that have a mean hydraulic
conductivity than or equal to 1.10-5 m/s. For this
purpose the norm ASTM 6391 “Standard Test Method
for Field Measurement of Hydraulic Conductivity of
Porous Materials Using Two Stages of Infiltration
from a Borehole” explains with accuracy the purpose,
terminology, apparatus, test site, test procedure and
calculation of TSB method
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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