Many studies deal with the correlation between landslide velocity and damage degree of buildings or infrastructure. For shallow or moderate depth, slow landslides such as complex, slow flow or ...roto-translation type are well studied by InSAR or other ground-based instruments to retrieve a matrix correlation of velocity damage. However, few of them investigate the effects of deep-seated gravitational slope deformation (DsGSD) displacement. These phenomena usually have a very deep sliding surface, covering a vast area with constant velocity. This study investigates the building damage, mapped with a detailed field survey, correlated with one of the massive DsGSD of the Alps (Sauze d’Oulx DsGSD, NW Italy) affecting several villages. We used multi-temporal InSAR data and ground-based monitoring to obtain 26 years of displacement time series. The results show a complicated correlation, in which several factors influence the degree of building damage, such as the material of the building, their state of maintenance, the position on DsGSD, the depth of movement, the secondary process or the velocity range variability. A simple correlation with velocity is not exhaustive: the central part of DsGSD shows a higher velocity rate (up to 30 mm/yr), but with limited damage; while at the toe boundary of deformation, slow rate of movement produces more severe damage. These findings show that several in-depth studies should integrate velocity data from monitoring to assess the coexistence of these huge complex phenomena and define their impact on anthropic structures before making a risk assessment and a suitable land use planning of mountainous territory.
The status of contamination by chemical pollutants on large filter feeding sharks is still largely unknown. This study investigated for the first time the presence of legacy, emerging contaminants ...and trace elements in multiple tissues of basking sharks. In general, skin showed higher concentration of legacy and emerging contaminants probably due to pollutants being adsorbed onto the dermal denticles of the skin rather than accumulated in the tissue itself. Contaminants measured in both subcutaneous tissue and muscles appeared to strongly correlate with each other, indicating that the former might be a good proxy of muscle contamination in basking sharks. Considering the migratory nature of this species, longevity and feeding ecology, this species represents the perfect candidate to act as early warning bioindicator of regional contamination. In this context, non-lethal subcutaneous biopsies could allow the early detection of any temporal variation in the bioaccumulation of pollutants in the Mediterranean Sea.
•Trace elements, PCBs, DDT and PFAS were quantified in basking sharks.•The DDE/DDT ratio suggests that residues derive from old input in the Mediterranean.•A predominance of odd-chain length (PFTrDA and PFUnA) was found.•Correlations between pollutant levels in subcutaneous tissue and muscles were found.•Subcutaneous tissue is a good proxy of muscle levels for PFAS, PCBs and few elements.
V391 Peg (alias HS 2201+2610) is a subdwarf B (sdB) pulsating star that shows both
p
- and
g
-modes. By studying the arrival times of the
p
-mode maxima and minima through the O–C method, in a ...previous article the presence of a planet was inferred with an orbital period of 3.2 years and a minimum mass of 3.2
M
Jup
. Here we present an updated O–C analysis using a larger data set of 1066 h of photometric time series (~2.5× larger in terms of the number of data points), which covers the period between 1999 and 2012 (compared with 1999–2006 of the previous analysis). Up to the end of 2008, the new O–C diagram of the main pulsation frequency (
f
1
) is compatible with (and improves) the previous two-component solution representing the long-term variation of the pulsation period (parabolic component) and the giant planet (sine wave component). Since 2009, the O–C trend of
f
1
changes, and the time derivative of the pulsation period (
p
.
) passes from positive to negative; the reason of this change of regime is not clear and could be related to nonlinear interactions between different pulsation modes. With the new data, the O–C diagram of the secondary pulsation frequency (
f
2
) continues to show two components (parabola and sine wave), like in the previous analysis. Various solutions are proposed to fit the O–C diagrams of
f
1
and
f
2
, but in all of them, the sinusoidal components of
f
1
and
f
2
differ or at least agree less well than before. The nice agreement found previously was a coincidence due to various small effects that are carefully analyzed. Now, with a larger dataset, the presence of a planet is more uncertain and would require confirmation with an independent method. The new data allow us to improve the measurement of
p
.
for
f
1
and
f
2
: using only the data up to the end of 2008, we obtain
p
.
1
= (1.34 ± 0.04) × 10
−12
and
p
.
2
= (1.62 ± 0.22) × 10
−12
. The long-term variation of the two main pulsation periods (and the change of sign of
p
.
1
) is visible also in direct measurements made over several years. The absence of peaks near
f
1
in the Fourier transform and the secondary peak close to
f
2
confirm a previous identification as
l
= 0 and
l
= 1, respectively, and suggest a stellar rotation period of about 40 days. The new data allow constraining the main
g
-mode pulsation periods of the star.
ABSTRACT
We present rotation period measurements for 107 M dwarfs in the mass range $0.15\!-\!0.70 \, \mathrm{M}_\odot$ observed within the context of the APACHE photometric survey. We measure ...rotation periods in the range 0.5–190 d, with the distribution peaking at ∼30 d. We revise the stellar masses and radii for our sample of rotators by exploiting the Gaia DR2 data. For ${\sim}20{{\ \rm per\ cent}}$ of the sample, we compare the photometric rotation periods with those derived from different spectroscopic indicators, finding good correspondence in most cases. We compare our rotation periods distribution to the one obtained by the Kepler survey in the same mass range, and to that derived by the MEarth survey for stars in the mass range $0.07\!-\!0.25 \, \mathrm{M}_\odot$. The APACHE and Kepler periods distributions are in good agreement, confirming the reliability of our results, while the APACHE distribution is consistent with the MEarth result only for the older/slow rotators, and in the overlapping mass range of the two surveys. Combining the APACHE/Kepler distribution with the MEarth distribution, we highlight that the rotation period increases with decreasing stellar mass, in agreement with previous work. Our findings also suggest that the spin-down time scale, from fast to slow rotators, changes crossing the fully convective limit at ${\approx}0.3 \, \mathrm{M}_\odot$ for M dwarfs. The catalogue of 107 rotating M dwarfs presented here is particularly timely, as the stars are prime targets for the potential identification of transiting small planets with TESS and amenable to high-precision mass determination and further atmospheric characterization measurements.
Aims.
We aim to investigate variations in the arrival time of coherent stellar pulsations due to the light-travel time effect to test for the presence of sub-stellar companions. Those companions are ...the key to one possible formation scenario of apparently single sub-dwarf B stars.
Methods.
We made use of an extensive set of ground-based observations of the four large amplitude
p
-mode pulsators DW Lyn, V1636 Ori, QQ Vir, and V541 Hya. Observations of the TESS space telescope are available on two of the targets. The timing method compares the phase of sinusoidal fits to the full multi-epoch light curves with phases from the fit of a number of subsets of the original time series.
Results.
Observations of the TESS mission do not sample the pulsations well enough to be useful due to the (currently) fixed two-minute cadence. From the ground-based observations, we infer evolutionary parameters from the arrival times. The residual signals show many statistically significant periodic signals, but no clear evidence for changes in arrival time induced by sub-stellar companions. The signals can be explained partly by mode beating effects. We derive upper limits on companion masses set by the observational campaign.
Depuis une vingtaine d'années, les ateliers pour enfants n'ont cessé de se multiplier dans les musées d'art, les précurseurs ayant souvent été les musées d'art moderne et contemporain, auxquels nous ...allons nous intéresser plus particulièrement. Quels sont donc les buts et les spécificités de ce type d'ateliers, que peut apporter à l'enfant la fréquentation des œuvres d'art?
This contribution focuses the attention on an innovative approach in diagnostics of paintings, based on the combine use of two imaging techniques named Hypecolorimetric Multispectral Imaging (HMI) ...and Pulse Compression Thermography (PuCT) applied to a 15th century wall painting, attributed to the Italian artist Antonio del Massaro, also known as Pastura. HMI technique is based on the simultaneous exploitation of the electromagnetic spectrum from the ultraviolet to the near infrared region. The acquisition, made under a standard metric, allows for characterizing the investigated surfaces in a more detailed way than the standard colorimetry. The system transforms any spectra in the range 300-1000nm into sevenfold hypecolorimetric coordinates. HMI guarantees very high radiometric (better than 95%) and colorimetric precision (better than ΔE = 2). PuCT is a thermography technique based on the use of coded modulated heating stimuli in combination with the pulse-compression technique. A PuCT scheme, based on coded LED excitation capable of optimizing the estimation of the impulse responses compared to the state-of-the-art PuCT literature has also been proposed. The combined use of HMI and PuCT recently revealed its potentiality in the investigation of important panel paintings by highlighting hidden details, mapping the conservation status, characterizing painting materials, etc. in a completely non-invasive way. Their combined capabilities are here tested on a wall painting representing the Madonna with the Child and the Saints Jerome and Francis, which was investigated during the restoration in the Laboratory in order to supply information about the materials and techniques.
The APACHE Project Sozzetti, A.; Bernagozzi, A.; Bertolini, E. ...
EPJ Web of conferences,
01/2013, Volume:
47
Journal Article
Peer reviewed
Open access
First, we summarize the four-year long efforts undertaken to build the final setup of the APACHE Project, a photometric transit search for small-size planets orbiting bright, low-mass M dwarfs. Next, ...we describe the present status of the APACHE survey, officially started In July 2012 at the site of the Astronomical Observatory of the Autonomous Region of the Aosta Valley, in the Western Italian Alps. Finally, we briefly discuss the potentially far-reaching consequences of a multi-technique characterization program of the (potentially planet-bearing) APACHE targets.
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