1,721,024 research outputs found
Water-gas dynamics and coastal land subsidence over Chioggia Mare field, Northern Adriatic sea
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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
Interpretation of radioactive marker measurements to evaluate compaction in the Northern Adriatic gas fields
No full textWhen the field consists of multi-pay reservoirs with the heterogeneity scale of the porous medium smaller than the marker spacing (10.5 m) a great care must be exercised in the interpretation of a radioactive marker survey. The rock may expand, or, if the monitored depth interval incorporates thin low permeable layers or the measurement is made in an active well, the measured compaction can occur in non-oedometric conditions. In the present paper a set of radioactive marker measurements made by ENI-Divisione Agip over the last decade in 3 deep boreholes of the Northern Adriatic basin are simulated with the aid of a FE coupled poroelastic model. The modeling results show that the measurements can be reproduced satisfactorily in several case, both from a qualitative and also quantitative viewpoint, and indicate that an efficient marker installation requires that the monitored depth interval be made mostly of sand entirely depleted, with the markers placed far from a producing well and approximately 10.5 m apart. The cM constitutive law used in the numerical analysis appears to be realistically accurate for a depth larger than 2500 m and generally underestimated between 800 and 1500 m. The measured expansions due to a natural pore pressure recovery allow for the assessment also of the reservoir cM under unloading/reloading conditions
Valutazione della ipoacusia in responsabilita' civile. Analisi Comparativa fra due metodiche
No full textStochastic analysis of the Venice uplift due to seawater injection into deep aquifers
No full textIn recent years, a project of anthropogenic Venice uplift by seawater injection into a deep brackish aquifer underlying the lagoon has been advanced. A major concern is the possible generation of differential vertical displacements at the ground surface, which should not exceed prescribed regulatory thresholds to guarantee the structural preservation of historical buildings. In this work, we analyze the effects that spatially heterogeneous hydraulic conductivity distributions in the injected formations may have on the uniformity of the induced land uplift
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
Stochastic compressibility for land subsidence modelling
No full textNumerical models for predicting land subsidence due to fluid withdrawal require the correct evaluation of representative mechanical properties of the deforming porous medium. One such property is the vertical uniaxial compressibility cM which is obtained through either lab oedometer tests or in situ measurements, and typically exhibits a marked scattering. The present communication addresses the influence of the cM uncertainty for the predicted land settlement using a stochastic approach where cM is regarded as a random variable. A compressibility law, characterized by a log-normal distribution with depth-dependent mean and constant variance, is implemented into a Finite Element poroelastic model and used in a preliminary study based on the Monte Carlo method. The results show how the cM variance affects the reliability of the expected land subsidence and point out the impact of the cM uncertainty on the quality of prediction
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