10,470 research outputs found
Review article "Remarks on factors influencing shear wave velocities and their role in evaluating susceptibilities to earthquake-triggered slope instability: case study for the Campania area (Italy)"
Shear wave velocities have a fundamental role in connection with the mitigation of seismic hazards, as their low values are the main causes of site amplification phenomena and can significantly influence the susceptibility of a territory to seismic-induced landslides. The shear wave velocity (Vs) and modulus (<i>G</i>) of each lithological unit are influenced by factors such as the degree of fracturing and faulting, the porosity, the clay amount and the precipitation, with the latter two influencing the unit water content. In this paper we discuss how these factors can affect the Vs values and report the results of different analyses that quantify the reduction in the rock Vs and shear modulus values connected to the presence of clay and water. We also show that significant results in assessing seismic-induced slope failure susceptibility for land planning targets could be achieved through a careful evaluation, based only on literature studies, of the geo-lithological and geo-seismic features of the study area
No more time to stay ‘single’ in the detection of Anisakis pegreffii, A. simplex (s. s.) and hybridization events between them: a multi-marker nuclear genotyping approach
A multi-marker nuclear genotyping approach was performed on larval and adult specimens of Anisakis spp. (N = 689) collected from fish and cetaceans in allopatric and sympatric areas of the two species Anisakis pegreffii and Anisakis simplex
(s. s.), in order to: (1) identify specimens belonging to the parental taxa by using nuclear markers (allozymes loci) and sequence analysis of a new diagnostic nuclear DNA locus (i.e. partial sequence of the EF1 α−1 nDNA region) and (2) recognize hybrid categories. According to the Bayesian clustering algorithms, based on those markers, most of the individuals
(N = 678) were identified as the parental species [i.e. A. pegreffii or A. simplex (s. s.)], whereas a smaller portion (N = 11)
were recognized as F1 hybrids. Discordant results were obtained when using the polymerase chain reaction–restriction
fragment length polymorphisms (PCR–RFLPs) of the internal transcribed spacer (ITS) ribosomal DNA (rDNA) on
the same specimens, which indicated the occurrence of a large number of ‘hybrids’ both in sympatry and allopatry.
These findings raise the question of possible misidentification of specimens belonging to the two parental Anisakis and
their hybrid categories derived from the application of that single marker (i.e. PCR–RFLPs analysis of the ITS of
rDNA). Finally, Bayesian clustering, using allozymes and EF1 α−1 nDNA markers, has demonstrated that hybridization
between A. pegreffii and A. simplex (s. s.) is a contemporary phenomenon in sympatric areas, while no introgressive hybridization takes place between the two species
Semiclassical almost isometry
Let M be a complex projective manifold, and L an Hermitian ample line bundle
on it. A fundamental theorem of Gang Tian, reproved and strengthened by
Zelditch, implies that the Khaeler form of L can be recovered from the
asymptotics of the projective embeddings associated to large tensor powers of
L. More precisely, with the natural choice of metrics the projective embeddings
associated to the full linear series |kL| are asymptotically symplectic, in the
appropriate rescaled sense. In this article, we ask whether and how this result
extends to the semiclassical setting. Specifically, we relate the Weinstein
symplectic structure on a given isodrastic leaf of half-weighted
Bohr-Sommerfeld Lagrangian submanifolds of M to the asymptotics of the the
pull-back of the Fubini-Study form under the semiclassical projective maps
constructed by Borthwick, Paul and Uribe.Comment: exposition improve
Magnetic signature of submarine volcanoes in the Phlegrean Fields-Ischia Ridge (North-Western side of the Bay of Naples, Southern Italy)
This paper presents a study of the Phlegrean Fields-Ischia submarine ridge by the analysis and interpretation of
high-resolution aeromagnetic data recently acquired in the Western Procida offshore. The investigated area is located
along the ridge connecting Ischia to the Phlegrean Fields and is characterized by the existence of several
monogenetic volcanoes aligned on a NE-SW system of faults. The high-resolution magnetic data yielded new
information on the area, highlighting particularly the signature of a volcanic body located between Pt. Serra and
the Ruommoli shoal. This structure has not been clearly described before and we named it as the Pt. Serra submarine
volcano. The computation of the analytic signal and horizontal gradient of the data distinctly located this
structure and definined the position of its rims. A 2D modeling and 3D inversion of data provided information
on the volcano’s thickness, width and magnetization, disclosing a meaningful igneous body extending down to
several hundred meters b.s.l
Drilling polymeric matrix composites
This chapter presents the basics of drilling of polymeric matrix composites
(PMCs). PMCs are becoming widely used in the manufacturing of products where
a high mechanical strength must be accompanied by a low weight. However, the
machining of PMCs implies coping with problems that are not encountered when
machining other materials. Drilling is a particularly critical operation for PMCs
laminates because the large concentrated forces generated can lead to widespread
damage. This damage causes aesthetic problems but, more importantly, may compromise
the mechanical properties of the finished part
A Computationally Efficient Tool for Assessing the Depth Resolution in Potential-Field Inversion
In potential-field inversion problems, it can be difficult to obtain reliable information about the
source distribution with respect to depth. Moreover, spatial resolution of the solution decreases
with depth, and in fact the more ill-posed the problem – and the more noisy the data – the less
reliable the depth information. Based on early work in depth resolution, defined in terms of
the singular value decomposition, we introduce a tool APPROXDRP which uses an approximation of the singular vectors obtained by the iterative Lanczos bidiagonalization algorithm,
making it well suited for large-scale problems. This tool allows a computational/visual analysis
of how much the depth resolution in a computational potential-field inversion problem can be
obtained from the given data.We show that when used in combination with a plot of the approximate SVD quantities, APPROXDRP may successfully show the limitations of depth resolution
resulting from noise in the data. This allows a reliable analysis of the retrievable depth information and effectively guides the user in choosing the optimal number of iterations, for a given
problem
Explicit characterization of the identity configuration in an Abelian Sandpile Model
Since the work of Creutz, identifying the group identities for the Abelian
Sandpile Model (ASM) on a given lattice is a puzzling issue: on rectangular
portions of Z^2 complex quasi-self-similar structures arise. We study the ASM
on the square lattice, in different geometries, and a variant with directed
edges. Cylinders, through their extra symmetry, allow an easy determination of
the identity, which is a homogeneous function. The directed variant on square
geometry shows a remarkable exact structure, asymptotically self-similar.Comment: 11 pages, 8 figure
SiPM and front-end electronics development for Cherenkov light detection
The Italian Institute of Nuclear Physics (INFN) is involved in the
development of a demonstrator for a SiPM-based camera for the Cherenkov
Telescope Array (CTA) experiment, with a pixel size of 66 mm. The
camera houses about two thousands electronics channels and is both light and
compact. In this framework, a R&D program for the development of SiPMs suitable
for Cherenkov light detection (so called NUV SiPMs) is ongoing. Different
photosensors have been produced at Fondazione Bruno Kessler (FBK), with
different micro-cell dimensions and fill factors, in different geometrical
arrangements. At the same time, INFN is developing front-end electronics based
on the waveform sampling technique optimized for the new NUV SiPM. Measurements
on 11 mm, 33 mm, and 66 mm NUV SiPMs
coupled to the front-end electronics are presentedComment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Leaf water diffusion dynamics in vivo through a sub-terahertz portable imaging system
The development of terahertz based technology has given the opportunity for the realization of non destructive techniques capable of gaining meaningful information on delicate systems such as biological samples. Here, the health status of leaves in vivo has been monitored through a portable terahertz imaging system. The data have been extracted and analysed from the images acquired and compared with analogous results reported in the literature on similar systems. The possibilty of extracting additional information from the images regarding leaf details has also been explored
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