Collapse displacements of masonry arch with geometrical uncertainties on spreading supports

This work is aimed at evaluating the collapse displacement of masonry arch subjected to spreading supports. This is achieved through a general application of the virtual works principle. The problem is described in a finite displacements formulation and investigated with a probabilistic approach, also considering the effects of the geometrical uncertainties. This aspect is related to the imperfections of the voussoirs, which affect the structural shape. The comparison between the numerical and experimental results, derived both by the literature and laboratory tests, confirms that the geometrical irregularities can significantly affect the results obtained on the nominal structural geometry. Moreover, the disagreement observed in the experimental tests is explained

Detection of pulsations and a spectral feature in the X-ray emission of the isolated neutron star 1RXS J214303.7+065419/RBS 1774

We report on the results of a deep XMM-Newton observation of RBS 1774, the most recent dim isolated neutron star candidate found in the ROSAT archive data. Spectral and timing analysis of the high-quality PN and MOS data confirm the association of this source with an isolated neutron star. The spectrum is thermal and blackbody-like, and there is evidence at a significance level > 4sigma that the source is an X-ray pulsar, with spin period of 9.437 s. Spectral fitting reveils the presence of an absorption feature at ~0.7 keV, but at this level data do not have enough resolution to allow us to discriminate between an absorption line or an edge. We compare the newly measured properties of RBS 1774 with those of other known dim isolated neutron stars, and discuss possible interpretations for the absorption feature.Comment: 21 pages, 5 figures, ApJ accepte

Distribution of amiodarone and desethylamiodarone in a patient with acute myocardial infarction after intravenous administration

The autopsy tissues concentration of amiodarone and desethylamiodarone of a man with acute myocardial infarction treated acutely with intravenous amiodarone is reported. Our data indicate that amiodarone is quickly distributed into all highly perfused tissues after intravenous administration with a high amiodarone/desethylamiodarone ratio. We also report here the autopsy case of a woman who died after 30 days of oral therapy with amiodarone. The increase in heart/plasma ratio of amiodarone and desethylamiodarone concentrations and the decrease in amiodarone/desethylamiodarone ratio after one month of therapy could explain the latency in the antiarrhythmic action of the drug

Study on the differences of BMI between olms found in cave and the ones sampled in spring

The olm (Proteus anguinus) is a blind amphibian, depigmented and with an extremely reduced metabolism. These are adaptations to cave life that allow the animals to exploit this hostile (from a human perspective) habitat. Adaptations to cave life, should prevent successful exploitation of the external environment. However, although the Proteus is a cave animal, it has been reported by some authors in the spring environment, Our previous results showed that this presence, would seem not to be random, in but linked to very specific factors such as hydroperiod the absence of potential predators. In the light of these results, we have conducted a study with the aim of verifying whether the Proteus benefits from exploiting the trophic resources occurring in springs. Since June 2020 we have sampled 64 springs and 12 caves in the Monfalcone province, each olm found during the sampling was photographed, measured and weighed. A total of 73 different olms were analyzed and the Body Mass Index (BMI) was calculated for each individual. Olms found in springs had a significantly higher BMI than those found in caves. The BMI of springs’ olms was significantly related to amount of the trophic available, evidencing that they took advantages from exploiting the external environment. These results contribute to support the hypothesis of the non-random presence of the Proteus in the spring environment, the olm, in fact, seem to benefit from this type of habitat taking advantage of the greater number of resources present in it

Radiative acceleration and transient, radiation-induced electric fields

The radiative acceleration of particles and the electrostatic potential fields that arise in low density plasmas hit by radiation produced by a transient, compact source are investigated. We calculate the dynamical evolution and asymptotic energy of the charged particles accelerated by the photons and the radiation-induced electric double layer in the full relativistic, Klein-Nishina regime. For fluxes in excess of $10^{27}$ ${\rm erg} {\rm cm}^{-2} {\rm s}^{-1}$, the radiative force on a diluted plasma (n\la 10^{11} cm$^{-3}$) is so strong that electrons are accelerated rapidly to relativistic speeds while ions lag behind owing to their larger inertia. The ions are later effectively accelerated by the strong radiation-induced double layer electric field up to Lorentz factors $\approx 100$, attainable in the case of negligible Compton drag. The asymptotic energies achieved by both ions and electrons are larger by a factor 2--4 with respect to what one could naively expect assuming that the electron-ion assembly is a rigidly coupled system. The regime we investigate may be relevant within the framework of giant flares from soft gamma-repeaters.Comment: 14 pages, 7 figures, ApJ, in press (tentatively scheduled for the v. 592, 2003 issue

Optical and Ultraviolet Observations of the Very Young Type IIP SN 2014cx in NGC 337

Extensive photometric and spectroscopic observations are presented for SN 2014cx, a type IIP supernova (SN) exploding in the nearby galaxy NGC 337. The observations are performed in optical and ultraviolet bands, covering from -20 to +400 days from the peak light. The stringent detection limit from prediscovery images suggests that this supernova was actually detected within about 1 day after explosion. Evolution of the very early-time light curve of SN 2014cx is similar to that predicted from a shock breakout and post-shock cooling decline before reaching the optical peak. Our photometric observations show that SN 2014cx has a plateau duration of ~ 100 days, an absolute V-band magnitude of ~ -16.5 mag at t~50 days, and a nickel mass of 0.056+-0.008 Msun. The spectral evolution of SN 2014cx resembles that of normal SNe IIP like SN 1999em and SN 2004et, except that it has a slightly higher expansion velocity (~ 4200 km/s at 50 days). From the cooling curve of photospheric temperature, we derive that the progenitor has a pre-explosion radius of ~ 640 Rsun, consistent with those obtained from SNEC modeling (~ 620 Rsun) and hydrodynamical modeling of the observables (~ 570 Rsun). Moreover, the hydrodynamical simulations yield a total explosion energy of ~ 0.4*10e51 erg, and an ejected mass of ~ 8 Msun. These results indicate that the immediate progenitor of SN 2014cx is likely a red supergiant star with a mass of ~ 10 Msun.Comment: 47 pages, 12 figures and 7 tables. Accepted by Ap