Search results for "discontinuity"
showing 10 items of 76 documents
Coseismic Damage at an Archaeological Site in Sicily, Italy: Evidence of Roman Age Earthquake Surface Faulting
2018
Archaeoseismology can provide a useful chronological tool for constraining earthquakes and documenting significant evidence that would otherwise be lost. In this paper, we report a case of surface faulting on ancient man-made structures belonging to the archaeological site of Santa Venera al Pozzo situated along the eastern flank of Mt. Etna volcano in eastern Sicily (southern Italy), which is affected by well-developed tectonic faults. Geological surveys highlight a set of fractures affecting the archaeological ruins, suggesting the occurrence of a capable fault zone across the area. An integrated geophysical survey was carried out in order to identify the main subsurface tectonic disconti…
Improved global-local model to predict guided-wave scattering patterns from discontinuities in complex parts
2019
Ultrasonic guided-wave testing can greatly benefit from (1) an ability to provide quantitative information on the damage that is being detected, and (2) an ability to select the best mode-frequency combination for maximum sensitivity to a given type of damage. Achieving these capabilities in complex structures (e.g. nonprismatic structures such as a stiffened panel in aerospace fuselages) is a nontrivial task. This paper will discuss an improved Global-Local (GL) method where the geometrical “local” discontinuity (e.g. the stiffener) is modelled by traditional FE discretization and the rest of the structure (“global” part) is modelled by Semi-Analytical Finite Element (SAFE) cross-sectional…
When does Regression discontinuity design work? Evidence from random election outcomes
2018
We use elections data in which a large number of ties in vote counts between candidates are resolved via a lottery to study the personal incumbency advantage. We benchmark non‐experimental regression discontinuity design (RDD) estimates against the estimate produced by this experiment that takes place exactly at the cutoff. The experimental estimate suggests that there is no personal incumbency advantage. In contrast, conventional local polynomial RDD estimates suggest a moderate and statistically significant effect. Bias‐corrected RDD estimates that apply robust inference are, however, in line with the experimental estimate. Therefore, state‐of‐the‐art implementation of RDD can meet the re…
Inverse symmetry breaking and the exact renormalization group
1996
We discuss the question of inverse symmetry breaking at non-zero temperature using the exact renormalization group. We study a two-scalar theory and concentrate on the nature of the phase transition during which the symmetry is broken. We also examine the persistence of symmetry breaking at temperatures higher than the critical one.
The Landslide of Agrigento Hill (Sicily, Italy)
2018
This paper illustrated the geological, morphological and hydrogeological studies performed for the analysis and monitoring of the landslide involving the northern side of the hill of Agrigento (335 m a.s.l.) on which the ancient Cathedral was built during the 11th Century. The hill is made of a typical Plio-Pleistocene transgressive succession made of clays (M. Narbone formation), calcarenites, sands and clayey soils (Agrigento formation). The area has been unstable since 1315, involving both the little-welded, very porous and fractured calcarenitic sections (E-W) from Pleistocene and the clay layers interstratified within these sections. Since 1924, from time to time, various typologies of…
Learning in sport : from life skills to existential learning
2020
Youth sport is habitually promoted as an important context for learning that contributes to a person’s broader development beyond sport-specific skills. A growing body of research in this area has operated within a life skills discourse that focuses on useful, positive and decontextualised skills in the production of successful and adaptive citizens. In this paper, we argue that the ideological discourse of life skills, underpinned by ideas about sport-based positive youth development, has unduly narrowed the research on learning in sport to only what is deemed functional, teachable, and economically productive. After considering the problems associated with the currently dominant life skil…
Scratching Beneath the Surface: Distribution Dynamics
2018
This chapter explores how regional inequality has evolved in terms of mobility and persistence. Different statistical methods are used to determine whether there has been a general trend whereby the richest regions have maintained their position over time or whether, on the contrary, any relevant changes can be seen in the positions occupied by the various regions in terms of income levels per capita. The results allow identifying stories of relative success or failure among Spanish regions, discover when exactly these changes were most frequent, and then construct hypotheses about the economic and institutional conditions which led to the biggest changes in the map of regional inequality i…
Persistence of Asteroids After a Close Encounter
1999
We present here a first approximation to the planar circular restricted 2 + 2 problem. In this four body problem, we consider that the two secondaries do not affect the primaries but they do influence each other. It can be seen as a model for near collision orbits of two asteroids if the primaries are the Sun and Jupiter ([3], [5]). In particular, we analyze the values of the Jacobi constant of the two asteroids before and after the close approach.
The Latomiae of Syracuse: A Geotechnical Mapping Through Rock Reflectivity
2014
The archeological site of the Latomia del Paradiso (Syracuse) is endangered by severe instability phenomena due to the shape of walls and underground excava-tion related with the poor mechanical characteristics of the weathered and wet rock. The failure of huge blocks from the ceiling of the underground areas and the detaching of rock "flakes" from the walls surface make the geotechnical zon-ing particularly complex. the zoning is based on the characteristics of the rock wall surface that, in first approximation, can be distinguished in regularized sur-faces because of mining , and in irregular surfaces characterized by fracture prop-agation. The elaboration of reflectivity values obtained …
How to define variation of physical properties normal to an undulating one-dimensional object.
2009
One-dimensional flexible objects are abundant in physics, from polymers to vortex lines to defect lines and many more. These objects structure their environment and it is natural to assume that the influence these objects exert on their environment depends on the distance from the line-object. But how should this be defined? We argue here that there is an intrinsic length scale along the undulating line that is a measure of its "stiffness" (i.e., orientational persistence), which yields a natural way of defining the variation of physical properties normal to the undulating line. We exemplify how this normal variation can be determined from a computer simulation for the case of a so-called b…