1,721,005 research outputs found
Geomechanical characterisation of the outcropping rock masses in the immediate vicinity of Wadi El-Kaffrein Dam site (Jordan)
No full textthis paper, the geomechanical characteristics of the discontinuities present in the rock masses, exposed in and around the existing Kaffrein dam site (Western
~,Jan), have been investigated for a probable heightening project of the dam in the near future.
r this purpose, eighteen detailed line surveys were carried out to determine the geometrical and the mechanical properties of the discontinuities. These
.tions were located on both the abutments as well as on the exposed rocks near the reservoir area.
lalysis of the discontinuity orientations, plotted on equal-area stereographic contour nets, have indicated the presence of two sub-vertical joint sets and a
rd one attributed to bedding planes. On the one hand, right abutment rock masses are characterised by low persistence, closely spaced joints that caused
e formation of small to very small block sizes. On the other hand, exposed rocks on the left abutment reflect the presence of closely to widely spaced,
oderately persistent joints which result in small sized blocks.
':k mass Uniaxial Compression Strength (UCS) was determined both in the laboratory and in situ. In situ measurements classified the rock masses as
:~g, while those measured in the laboratory, classified the rock masses as weak to moderately strong. Low UCS values were assigned to samples taken
n the left abutment. Such values (UCS < 20 Mpa) are believed to be questionable in view of the large difference observed between these values and those
.~i.ned from in situ measurements (UCS = 80 MPa).
-k mass shear strength behaviour of the studied rocks was estimated considering the JRC, JCS of the main discontinuity sets as well as the empirical
,uulae of Barton and Choubey (1977). The estimated shear strength envelopes relevant to the rock masses of both abutments were similar, and thus, they
.:sent similar shear strength characteristics. These results indicate the necessity of conducting further laboratory tests on samples to be taken from the left
butment in order precisely to determine the spatiel variation of the shear strength parameters, taking into consideration that future works, regarding the
~illway heightening, are to be done on the left abutment.
ock mass quality was determined through the employment of the two widely known geomechanical classification systems : RMR and Q. Both systems
ssigned a fair to good quality class to the rocks of both abutments. The cross correlation of their results gave a regression equation that is closely similar to
tat of Bieniawski. However, it should be stressed that its validity is applicable, preferably, to the study area.
~e geological and geomechanical investigations, presented in this work, established two main problems that are directly related to the dam arts/or to any
; :ure developments or works related to it. The first, concerns the heterogeneous nature, from the fracture intensity point of view, of the rock masses of the
! rnmar formation. While the second, concerns the permeable alIuvial deposits which cover the reservoir area, through which, an unallowable quantity of
ping water is taking place.
',e conveyed results are believed to furnish valuable technical information regarding the geomecbanical behaviour of the exposed rock masses in the vicinity
' ~he dam. This information could be used to direct or to lead future field &/or technical works in an efficient way in order to pass to the design and execution
:ases
Expeditious seismic methods for noninvasive diagnostics of the dynamic characteristics of the subsoil in urban centers using Rayleigh waves: The case of the city of Ferrara
No full textExploring the paleolithic cave of Fumane (Italy): Geophysical methods as planning tool for archaeology
No full textGeophysical techniques are seldom used for the investigation of paleolithic archeological sites, mostly due to their sedimentary nature and the almost complete absence of architectural remains that can result in clear geophysical anomalies. The Fumane cave (Italy) is considered one of the most important sites in Europe. Recent investigations and studies carried out by the archaeological group of the Dep. Of Humanities (University of Ferrara) with the enrollment of the Department of Engineering of the same University allowed for the reconstruction of the 3D model of the Fumane Cave. This offered an opportunity for the applied geophysics group of the same university to assess the capability of Electrical Resistivity Tomography to retrieve subsurface information of archaeological interest. As primary goals, the study aimed at the creation of a three-dimensional resistivity model of the subsurface, to infer the nature of the sedimentary infill, so enabling a better understanding of the depositional processes involved in the formation of this important archaeological deposit and at the same time, for planning long-term field-investigations and to locate areas interesting for excavation. Moreover a Ground penetrating radar and a Nakamura survey were attempted in an integrate approach to test whether the combined methodologies could provide further insight about the subsurface. With respect to previous work, we present new and improved results both on ERT, GPR and HVSR. In particular, the HVSR test was accomplished to gain information about the maximum thickness of the deposit and to see if other impedance contrast discontinuities are present as was anticipated by previous archaeological studies
The HVSR technique from array data, speeding up mapping of paleo-surfaces and buried remains. The case of the Bronze-Age site of Pilastri (Italy)
No full textIn the framework of a geophysical survey at the “Pilastri Terramara“ Middle Bronze Age archeological site (Northern Italy), which aimed at using cost-effective approaches to investigate a 12.000 m2 portion of land, we verified that in this site the most commonly used GPR, magnetometry and ERT geophysical methods were hampered by specific unfavorable conditions. Since the main purpose of the survey was to obtain information on ancient walking surfaces, we speculated that compaction, caused by the trampling of human activity over centuries, increased both density and seismic velocity of these paleo-surfaces. Assuming that such compacted layers still lie embedded in the shallow subsurface we successfully used the Horizontal-to-Vertical Spectral Ratio of microtremors, popular as HVSR, as a mapping tool. HVSR technique is seldom used in archaeological studies. The curve obtained by this method shows peaks and features that can be associated to the elastic impedance contrasts of a layered subsurface. Results from a previous single-station HVSR survey carried out on the whole area and consisted of 67 measurement points, allowed to obtain an indication about acoustic impedance contrasts and to spot few anomalies. The preliminary, yet promising result however, needed further acquisitions in order to achieve a better spatial sampling. We then tested microtremors acquisition using a linear array of seismic prospection geophones (4.5 Hz proper frequency) which have a worse response with respect the short period sensor used in single-station configuration. Yet the use of the array allowed for a comparable mapping of both paleo-surfaces and anomalies and data collection was performed at 24 locations simultaneously, so greatly accelerating the field work. In the following the two approaches are compared and an anomaly is highlighted which was located outside the hypothesized Bronze Age settlement area. Once excavated, such feature revealed to be a layer of roman age remains. Further, we show our best GPR section over the same anomaly. An indication was present in the GPR section but this became clear only afterward
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
Earth Resistivity Tomography (ERT) investigation of Machaerus Fortress
No full textNew campaigns to survey the structures and materials, explorative studies and specialist localized surveys permit constant up-dates to knowledge of the fortress and the village in a broader cognitive framework concerning both historical aspects and this directly tied to the material consistency of the architectural remains. The aforementioned initiative also offers new occasion for assessing the future potential of the research and the risk levels for the structures. The results of Machaerus may constitute a useful cognitive element for comparison with other sites/monuments in Jordan and offer occasions for reflection about the current management policy of the historical and artistic patrimony.
In this work we present and discuss the results obtained following the application of the Electrical Resistivity Tomography (ERT) in the subsurface investigation of a portion of the Qala’at al Mishaqa
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
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