Cellular-Automata model for dense-snow avalanches

This paper introduces a three-dimensional model for simulating dense-snow avalanches, based on the numerical method of cellular automata. This method allows one to study the complex behavior of the avalanche by dividing it into small elements, whose interaction is described by simple laws, obtaining a reduction of the computational power needed to perform a three-dimensional simulation. Similar models by several authors have been used to model rock avalanches, mud and lava flows, and debris avalanches. A peculiar aspect of avalanche dynamics, i.e., the mechanisms of erosion of the snowpack and deposition of material from the avalanche is taken into account in the model. The capability of the proposed approach has been illustrated by modeling three documented avalanches that occurred in Susa Valley (Western Italian Alps). Despite the qualitative observations used for calibration, the proposed method is able to reproduce the correct three-dimensional avalanche path, using a digital terrain model, and the order of magnitude of the avalanche deposit volume

Impact of debris flows on filter barriers: Analysis based on site monitoring data

Debris flows are one of the most complex and devastating natural phenomena, and they affect mountainous areas throughout the world. Structural measures are currently adopted to mitigate the related hazard in urbanized areas. However, their design requires an estimate of the impact force, which is an open issue. The numerous formulae proposed in the literature require the assignment of empirical coefficients and an evaluation of the kinematic characteristics of the incoming flow. Both are generally not known a priori. In this article, we present the Grand Valey torrent site (Italian Alps). A monitoring system made up of strain gauges was installed on a filter barrier at the site, allowing the evaluation of impact forces. The system provides pivotal information for calibrating impact formulae. Two debris flows occurred during the monitoring period. We present the interpretation of videos, impact measurements, and the results of numerical analyses. The combined analysis allows a back calculation of the events in terms of forces, flow depth, and velocity. Thus, we investigate the applicability of the impact formulae suggested in the literature and of the recommended empirical coefficients. The results highlight that hydrostatic effects dominated the impact during the first event, while hydrodynamic effects prevailed in the second one

RICOVERI PER EFFETTI INDESIDERATI DA SOVRADOSAGGIO DI FARMACI PRESSO UN\u2019UNIT\uc0 OPERATIVA CARDIOLOGICA NEL PERIODO 2011-2013

Introduzione: Le statistiche dei casi di ricovero ospedaliero per effetti indesiderati da sovradosaggio farmacologico sono utili per valutare l\u2019incidenza di tale fenomeno nel mondo reale. Un sovradosaggio farmacologico pu\uf2 avvenire come conseguenza di un\u2019insufficiente o inadeguata comunicazione tra medico e paziente, per autoprescrizione o erronea assunzione di dosaggi superiori a quelli necessari, per erronea assunzione di due farmaci identici come molecola ma con nome commerciale diverso o per effetti collaterali imprevisti. Materiali e metodi: Sono state esaminate, retrospettivamente, le cartelle cliniche relative a tutti i ricoveri avvenuti presso l\u2019Unit\ue0 Operativa di Cardiologia del P.O. S. Antonio Abate di Trapani (ASP 9 - Sicilia) nel triennio compreso tra gennaio 2011 e dicembre 2013. Sono state ricercate le ospedalizzazioni avvenute per effetti indesiderati da sovradosaggio di farmaci appartenenti a varie classi quali digitalici, ACE-inibitori, betabloccanti e antiaritmici, in particolare l\u2019amiodarone. Risultati: Nel triennio in oggetto, su un totale di 7269 ospedalizzazioni, quelli per effetti indesiderati da sovradosaggio farmacologico sono stati 76 (1.05% del totale dei ricoveri). I pazienti ricoverati per tale motivo, 33 di sesso maschile e 43 di sesso femminile, avevano un\u2019et\ue0 compresa tra 62 e 90 anni. La Figura1 mostra le percentuali relative ai singoli farmaci interessati, secondo cui la principale causa di ricovero ospedaliero per effetti indesiderati da sovradosaggio farmacologico \ue8 attribuibile all\u2019amiodarone, antiaritmico di classe III, per i noti effetti collaterali a carico della tiroide e degli occhi. Segue la digitale, che ha causato nei pazienti bradiaritmie e in alcuni casi vere e proprie intossicazioni e, in percentuali minori, gli ACE-inibitori, cause di ipotensione e i betabloccanti, causa di bradicardia e ipotensione. Per tutti i casi l\u2019intervento mirava alla reversione della sintomatologia e alla momentanea sospensione dell\u2019assunzione. Per nessuno dei casi monitorati si \ue8 proposto il ricovero in terapia intensiva. Discussione: I ricoveri ospedalieri per effetti indesiderati da sovradosaggio farmacologico sono ancora un problema abbastanza diffuso nel mondo reale. Gli operatori sanitari, tra cui Medici e Farmacisti, dovrebbero ulteriormente mirare a una corretta informazione dei pazienti e dei loro familiari, in particolare al momento della dimissione, come prezioso e fondamentale strumento di prevenzione di questi danni iatrogenici che, a prescindere dei costi evitabili per il Sistema Sanitario Nazionale, possono comportare, se non adeguatamente trattati, rischi e gravi conseguenze per la salute

Methane and Nitrogen Abundances On Pluto and Eris

We present spectra of Eris from the MMT 6.5 meter telescope and Red Channel Spectrograph (5700-9800 angstroms; 5 angstroms per pix) on Mt. Hopkins, AZ, and of Pluto from the Steward Observatory 2.3 meter telescope and Boller and Chivens spectrograph (7100-9400 angstroms; 2 angstroms per pix) on Kitt Peak, AZ. In addition, we present laboratory transmission spectra of methane-nitrogen and methane-argon ice mixtures. By anchoring our analysis in methane and nitrogen solubilities in one another as expressed in the phase diagram of Prokhvatilov and Yantsevich (1983), and comparing methane bands in our Eris and Pluto spectra and methane bands in our laboratory spectra of methane and nitrogen ice mixtures, we find Eris' bulk methane and nitrogen abundances are about 10% and about 90%, and Pluto's bulk methane and nitrogen abundances are about 3% and about 97%. Such abundances for Pluto are consistent with values reported in the literature. It appears that the bulk volatile composition of Eris is similar to the bulk volatile composition of Pluto. Both objects appear to be dominated by nitrogen ice. Our analysis also suggests, unlike previous work reported in the literature, that the methane and nitrogen stoichiometry is constant with depth into the surface of Eris. Finally, we point out that our Eris spectrum is also consistent with a laboratory ice mixture consisting of 40% methane and 60% argon. Although we cannot rule out an argon rich surface, it seems more likely that nitrogen is the dominant species on Eris because the nitrogen ice 2.15 micron band is seen in spectra of Pluto and Triton.Comment: The manuscript has 44 pages, 15 figures, and four tables. It will appear in the Astrophysical Journa

Snow Avalanche Impact Measurements at the Seehore Test Site in Aosta Valley (NW Italian Alps)

In full-scale snow avalanche test sites, structures such as pylons, plates, or dams have been used to measure impact forces and pressures from avalanches. Impact pressures are of extreme importance when dealing with issues such as hazard mapping and the design of buildings exposed to avalanches. In this paper, we present the force measurements recorded for five selected avalanches that occurred at the Seehore test site in Aosta Valley (NW Italian Alps). The five avalanches were small to medium-sized and cover a wide range in terms of snow characteristics and flow dynamics. Our aim was to analyze the force and pressure measurements with respect to the avalanche characteristics. We measured pressures in the range of 2 to 30 kPa. Though without exhaustive measurements of the avalanche flows, we found indications of different flow regimes. For example, we could appreciate some differences in the vertical profile of the pressures recorded for wet dense avalanches and powder ones. Being aware of the fact that more complete measurements are necessary to fully describe the avalanche flows, we think that the data of the five avalanches triggered at the Seehore test site might add some useful information to the ongoing scientific discussion on avalanche flow regimes and impact pressure

Principi di dimensionamento della palificata loricata "Terrasafe"

Sulla base delle risultanze delle sperimentazioni in vera grandezza effettuate e dell’analisi strutturale dell’elemento Terrasafe assemblato nel presente lavoro è stato illustrata una procedura di calcolo della struttura quando sia stata installata in opera. La procedura proposta si basa sull’ipotesi che l’azione sollecitante sia la spinta attiva del terreno, che è stata ritenuta realistica nel caso in esame, data la grande deformabilità della struttura stessa e propone le metodologie di calcolo da adottarsi per le verifiche interne e esterne