1,123 research outputs found
Earthquake‐induced landslide scenarios for seismic microzonation. Application to the Accumoli area (Rieti, Italy)
Scenarios of earthquake-induced landslides are necessary for seismic microzonation (SM) studies since they must be integrated with the mapping of instability areas. The PARSIFAL (Probabilistic Approach to pRovide Scenarios of earthquake‐Induced slope FAiLures) approach provides extensive analyses, over tens to thousands of square kilometers, and is designed as a fully comprehensive methodology to output expected scenarios which depend on seismic input and saturation conditions. This allows to attribute a rating, in terms of severity level, to the landslide-prone slope areas in view of future engineering studies and designs. PARSIFAL takes into account first-time rock- and earth-slides as well as re-activations of existing landslides performing slope stability analyses of different failure mechanisms. The results consist of mapping earthquake-induced landslide scenarios in terms of exceedance probability of critical threshold values of co-seismic displacements (P[D≥Dc|a(t),ay]). PARSIFAL was applied in the framework of level 3 SM studies over the municipality area of Accumoli (Rieti, Italy), strongly struck by the 2016 seismic sequence of Central Apennines. The use of the PARSIFAL was tested for the first time to screen the Susceptibility Zones (ZSFR) from the Attention Zones (ZAFR) in the category of the unstable areas, according to the guidelines by Italian Civil Protection. The results obtained were in a GIS-based mapping representing the possibility for a landslide to be induced by an earthquake (with a return period of 475 years) in three different saturation scenarios (i.e. dry, average, full). Only 41% of the landslide-prone areas in the Municipality of Accumoli are existing events, while the remaining 59% is characterized by first-time earth- or rock-slides. In dry conditions, unstable conditions or P[D≥Dc|a(t),ay]>0 were for 54% of existing landslides, 17% of first-time rock-slides and 1% of first-time earth- slides. In full saturation conditions, the findings are much more severe since unstable conditions or P[D≥Dc|a(t),ay]>0 were found for 58% of the existing landslides and for more than 80% of first-time rock- and earth-slides. Moreover, comparison of the total area of the ZAFR versus ZSFR, resulted in PARSIFAL screening reducing of 22% of the mapped ZAFR
Cu-catalyzed Si-NWS grown on “carbon paper” as anodes for Li-ion cells
The very high theoretical capacity of the silicon (4200mAh/g more than 10 times larger than graphite), environmental-friendly, abundant and low-cost, makes it a potential candidate to replace graphite in high energy density Li-ion batteries. As a drawback, silicon suffers from huge volume changes (300%) on alloying and dealloying with Li, leading a structural deformation that induces disruption. The use of nanostructured silicon materials has been shown to be an effective way to avoid this mechanical degradation of the active material. In this paper the synthesis of silicon nanowires, grown on a highly porous 3D-like carbon paper substrate by CVD using Cu as the catalyst, is presented. The use of carbon paper allows to achieve remarkable loadings of active material (2-5 mg/cm2) and, consequently, high capacity densities. The silicon electrode was investigated both morphologically and electrochemically. To improve the electrochemical performance various strategies have been carried out. It was observed that a very slow first cycle (C/40), which helps the formation of a stable solid electrolyte interphase on the silicon surface, improves the performance of the cells; nevertheless, their cycle life has been found not fully satisfactory. Morphological analysis of the Si-NWs electrodes before and after cycling showed the presence of a dense silicon layer below the nanowires which could reduce the electrical contact between the active material and the substrate
Decidual endothelial cells express surface-bound C1q as a molecular bridge between endovascular trophoblast and decidual endothelium
This study was prompted by the observation that decidual endothelial cells (DECs), unlike endothelial cells (ECs) of blood vessels in normal skin, kidney glomeruli and brain, express surface-bound C1q in physiologic pregnancy. This finding was unexpected, because deposits of C1q are usually observed in pathologic conditions and are associated with complement activation. In the case of DECs, we failed to detect immunoglobulins and C4 co-localized with C1q on the cell surface. Surprisingly, DECs expressed mRNA for the three chains of C1q and secreted detectable level of this component in serum-free medium. The ability to synthesize C1q is acquired by DECs during pregnancy and is not shared by ECs obtained from endometrium and from other sources. Cell-associated C1q has a molecular weight similar to that of secreted C1q and is released from DECs following treatment with heparinase or incubation at low pH. This suggests that C1q binds to DECs and it is not constitutively expressed on the cell surface. C1q is localized at contact sites between endovascular trophoblast and DECs and acts as an intercellular molecular bridge because adhesion of endovascular trophoblast to DECs was inhibited by antibodies to C1q and to a receptor recognizing its globular portion expressed on trophoblast. © 2008 Elsevier Ltd. All rights reserved
Finite difference lattice Boltzmann model with flux limiters for liquid-vapor systems
In this paper we apply a finite difference lattice Boltzmann model to study
the phase separation in a two-dimensional liquid-vapor system. Spurious
numerical effects in macroscopic equations are discussed and an appropriate
numerical scheme involving flux limiter techniques is proposed to minimize them
and guarantee a better numerical stability at very low viscosity. The phase
separation kinetics is investigated and we find evidence of two different
growth regimes depending on the value of the fluid viscosity as well as on the
liquid-vapor ratio.Comment: 10 pages, 10 figures, to be published in Phys. Rev.
Shocked molecular hydrogen towards the Tornado nebula
We present near-infrared and millimetre-line observations of the Tornado
nebula (G357.7-0.1). We detected 2.12 micron_m H2 1-0 S(1) line emission
towards the suspected site of interaction with a molecular cloud revealed by
the presence of an OH(1720 MHz) maser. The distribution of the H2 emission is
well correlated with the nonthermal radio continuum emission from the Tornado,
and the velocity of the H2 emission spans over 100 km/s, which both imply that
the H2 emission is shock excited. We also detected millimetre-lines from 12CO
and 13CO transitions at the velocity of the maser, and mapped the distribution
of the molecular cloud in a 2 x 2 arcmin^2 region around the maser. The peak of
the molecular cloud aligns well with an indentation in the nebula's radio
continuum distribution, suggesting that the nebula's shock is being decelerated
at this location, which is consistent with the presence of the OH(1720 MHz)
maser and shocked H2 emission at that location.Comment: 10 pages, 8 figures, minor changes, accepted to MNRA
The GeV to TeV connection in the environment of SNR IC 443
We have recently interpreted the source MAGIC J0616+225 as a result of
delayed TeV emission of cosmic-rays diffusing from IC 443 and interacting with
a cloud in the foreground of the remnant. This model was used to make
predictions for future observations, especially those to be made with the Fermi
satellite. Just recently, AGILE, Fermi, and VERITAS have released new results
of their observations of IC 443. In this work, we compare them with the
predictions of our model, exploring the GeV to TeV connection in this region of
space. We use Fermi data to consider the possibility of constraining the
cosmic-ray diffusion features of the environment. We analyze the cosmic-ray
distributions, their interactions, and a possible detection of the SNR
environment in the neutrino channel.Comment: Accepted for publication in MNRAS. 20 pages, 10 figures, 1 tabl
Two-domains bulklike Fermi surface of Ag films deposited onto Si(111)-(7x7)
Thick metallic silver films have been deposited onto Si(111)-(7x7) substrates
at room temperature. Their electronic properties have been studied by using
angle resolved photoelectron spectroscopy (ARPES). In addition to the
electronic band dispersion along the high-symmetry directions, the Fermi
surface topology of the grown films has been investigated. Using ARPES, the
spectral weight distribution at the Fermi level throughout large portions of
the reciprocal space has been determined at particular perpendicular
electron-momentum values. Systematically, the contours of the Fermi surface of
these films reflected a sixfold symmetry instead of the threefold symmetry of
Ag single crystal. This loss of symmetry has been attributed to the fact that
these films appear to be composed by two sets of domains rotated 60 from
each other. Extra, photoemission features at the Fermi level were also
detected, which have been attributed to the presence of surface states and
\textit{sp}-quantum states. The dimensionality of the Fermi surface of these
films has been analyzed studying the dependence of the Fermi surface contours
with the incident photon energy. The behavior of these contours measured at
particular points along the Ag L high-symmetry direction puts forward
the three-dimensional character of the electronic structure of the films
investigated.Comment: 10 pages, 12 figures, submitted to Physical Review
Micromechanics of elastic lamellae: Unravelling the role of structural inhomogeneity in multi-scale arterial mechanics
Microstructural deformation of elastic lamellae plays important roles in maintaining arterial tissue homeostasis and regulating vascular smooth muscle cell fate. Our study unravels the underlying microstructural origin that enables elastic lamellar layers to evenly distribute the stresses through the arterial wall caused by intraluminal distending pressure, a fundamental requirement for tissue and cellular function. A new experimental approach was developed to quantify the spatial organization and unfolding of elastic lamellar layers under pressurization in mouse carotid arteries by coupling physiological extension–inflation and multiphoton imaging. Tissue-level circumferential stretch was obtained from analysis of the deformation of a thick-walled cylinder. Our results show that the unfolding and extension of lamellar layers contribute simultaneously to tissue-level deformation. The inner lamellar layers are wavier and unfold more than the outer layers. This waviness gradient compensates the larger tissue circumferential stretch experienced at the inner surface, thus equalizing lamellar layer extension through the arterial wall. Discoveries from this study reveal the importance of structural inhomogeneity in maintaining tissue homeostasis through the arterial wall, and may have profound implications on vascular remodelling in aging and diseases, as well as in tissue engineering of functional blood vessels
Cross-National Differences in Victimization : Disentangling the Impact of Composition and Context
Varying rates of criminal victimization across countries are assumed to be the outcome of countrylevel structural constraints that determine the supply ofmotivated o¡enders, as well as the differential composition within countries of suitable targets and capable guardianship. However, previous empirical tests of these ‘compositional’ and ‘contextual’ explanations of cross-national di¡erences
have been performed upon macro-level crime data due to the unavailability of comparable individual-level data across countries. This limitation has had two important consequences for cross-national crime research. First, micro-/meso-level mechanisms underlying cross-national differences cannot be truly inferred from macro-level data. Secondly, the e¡ects of contextual measures (e.g. income inequality) on crime are uncontrolled for compositional heterogeneity. In this
paper, these limitations are overcome by analysing individual-level victimization data across 18 countries from the International CrimeVictims Survey. Results from multi-level analyses on theft and violent victimization indicate that the national level of income inequality is positively related to risk, independent of compositional (i.e. micro- and meso-level) di¡erences. Furthermore, crossnational variation in victimization rates is not only shaped by di¡erences in national context, but
also by varying composition. More speci¢cally, countries had higher crime rates the more they consisted of urban residents and regions with lowaverage social cohesion.
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