A fully polarizable and dissociable potential for water

A new classical interaction potential for water simulations is presented. Water is modeled as a fully dissociable set of atoms with a point dipole, determined self-consistently, on every oxygen atom. The oxygen polarizability is not fixed but depends on the geometry of the system. We show that, in spite of the limited number of free parameters, the model reproduces the geometrical and vibrational properties of microclusters in a satisfactory way

An Exploratory Study of Field Failures

Field failures, that is, failures caused by faults that escape the testing phase leading to failures in the field, are unavoidable. Improving verification and validation activities before deployment can identify and timely remove many but not all faults, and users may still experience a number of annoying problems while using their software systems. This paper investigates the nature of field failures, to understand to what extent further improving in-house verification and validation activities can reduce the number of failures in the field, and frames the need of new approaches that operate in the field. We report the results of the analysis of the bug reports of five applications belonging to three different ecosystems, propose a taxonomy of field failures, and discuss the reasons why failures belonging to the identified classes cannot be detected at design time but shall be addressed at runtime. We observe that many faults (70%) are intrinsically hard to detect at design-time

Modeling of Euclidean braided fiber architectures to optimize composite properties

Three-dimensional braided fiber reinforcements are a very effective toughening mechanism for composite materials. The integral yarn path inherent to this fiber architecture allows for effective multidirectional dispersion of strain energy and negates delamination problems. In this paper a geometric model of Euclidean braid fiber architectures is presented. This information is used to determine the degree of geometric isotropy in the braids. This information, when combined with candidate material properties, can be used to quickly generate an estimate of the available load-carrying capacity of Euclidean braids at any arbitrary angle

FUTUR -E: Quale futuro per la centrale Marzocco a Livorno?

Lo scenario energetico italiano ha conosciuto, in questi ultimi anni, un cambiamento repentino e inedito sulle linee delle norme nazionali e sovranazionali in merito a questioni climatiche e ambientali. In particolare il settore elettrico ha un lungo passato fatto di impatti ambientali notevoli, data l'invasività e pervasività delle sue infrastrutture. Quest'ultimo settore è quello che ha registrato una maggiore rivoluzione in termini di risorse impiegate ma anche modello territoriale di rete e gestione. Il rapido sviluppo di nuove tecnologie ha assestato un duro colpo al vecchio sistema elettrico centralizzato che ha lasciato ormai lo schema "one-to-many" per passare ad uno più integrato. Cosa fare quindi con le vecchie infrastrutture elettriche? Possono essere considerate parte del patrimonio industriale e culturale italiano? A che stregua? Questo paper analizza innanzitutto il progetto promosso da Enel S.p.A. dal nome Futur-E, alludendo al futuro dell'energia. Il progetto Futur-E è nato all'inizio del 2015 per portare l'attenzione su questo particolare settore del patrimonio industriale, per lo più datato 1960-80 che in un breve periodo di tempo è stato considerato obsoleto, e quindi spesso chiuso e abbandonato. Il progetto comprende 22 centrali termoelettriche inserite nel territorio italiano, la cui vita è ormai cessata/sta cessando per motivi di obsolescenza tecnologica o mancato utilizzo. La maggior parte di questi insediamenti si trovano in zone rurali, ma alcune impianti, come Genova, La Spezia, Livorno, Piombino e Bari si trovano in aree periurbane o urbane e rappresentano aree strategiche sia dal punto di vista del posizionamento, che della dimensione dell'area, e dell'impatto che una possibile riconversione di questi impianti possano avere sulle città e aree metropolitane stesse. Il caso preso in considerazione è quello della Centrale Marzocco, sita a Livorno e scelta per la sua rilevanza architettonica, situazione urbana ambigua e interesse ambientale. L'impianto è infatti collocato vicino al centro cittadino all'interno dell'area industrial portuale, che costituisce un terzo dell'agglomerato urbano. Il paper ha come obiettivo l'analisi del sito e della città di Livorno, e lo studio di uno scenario di sviluppo per l'area che non neghi il suo passato produttivo ma che anzi, ne rafforzi l'identità industriale, mettendo in luce la qualità architettonica e paesaggistica di un'area al momento conclusa, rinnovando la sua vocazione inserendovi all'interno una funzione che può servire l'intera città per i prossimi decenni. Lo scenario prevede l'inserimento di funzioni che abbiano come tema centrale il ciclo e il ri-ciclo dell'acqua, promuovendo da una parte la valorizzazione dell'asset industriale e dall'altra la cultura dell'acqua in una città nata e scolpita da questa risorsa naturale

Thermal neutron captures on dd and 3^3He

We report on a study of the $nd$ and n\,^3He radiative captures at thermal neutron energies, using wave functions obtained from either chiral or conventional two- and three-nucleon realistic potentials with the hyperspherical harmonics method, and electromagnetic currents derived in chiral effective field theory up to one loop. The predicted $nd$ and n\,^3He cross sections are in good agreement with data, but exhibit a significant dependence on the input Hamiltonian. A comparison is also made between these and new results for the $nd$ and n\,^3He cross sections obtained in the conventional framework for both potentials and currents.Comment: 4 pages, 4 eps figures; references added; corrections to text and abstract as suggested by referee adde

Electromagnetic structure of A=2 and 3 nuclei in chiral effective field theory

The objectives of the present work are twofold. The first is to address and resolve some of the differences present in independent, chiral-effective-field-theory (\chiEFT) derivations up to one loop, recently appeared in the literature, of the nuclear charge and current operators. The second objective is to provide a complete set of \chiEFT predictions for the structure functions and tensor polarization of the deuteron, for the charge and magnetic form factors of 3He and 3H, and for the charge and magnetic radii of these few-nucleon systems. The calculations use wave functions derived from high-order chiral two- and three-nucleon potentials and Monte Carlo methods to evaluate the relevant matrix elements. Predictions based on conventional potentials in combination with \chiEFT charge and current operators are also presented. There is excellent agreement between theory and experiment for all these observables for momentum transfers up to q< 2.0-2.5 (1/fm); for a subset of them, this agreement extends to momentum transfers as high as q~5-6 (1/fm). A complete analysis of the results is provided.Comment: 34 pages, Revte

Effect of Finnsheep crossbreeding on Lamon sheep performance: in vivo traits

The objective of this trial was the comparison of the in vivo traits of Lamon (L), a local meat breed of the Eastern Italia Alps, and Finnsheep X Lamon (F x L) fattening lambs. Forty-one lambs (25 L and 16 F x L) of both sexes were weaned at 8 weeks of age and fattened for 14 weeks. The diet (11,6 MJ/kg d.m.M.E.) consisted of maize silage ad lib., 200 g/d of dried sugar beet pulp, 150 g/d of soybean meal and 30 g/d supplement. F x L lambs grew slightly more than L lambs (197 vs 176 g/d; P .1) while M.E. requirements for growth, estimated assuming a maintenance requirement of.44 MJ • d-1 • kg-1 • L.W.-75, resulted higher (+7 %) for F x L than for L lambs (2.18 vs 2.04 MJ • kgDG • kg-1 • L.W.-75; P < .1). The ram-lambs showed superior growth potential and feed efficiency in respect to the ewe-lambs. In conclusion it appears that crossbreeding with Finnsheep is not detrimental to the in vivo performance of fattening Lamon lambs except for a slight increase of the energy requirements for growth

Hospital volume allocation: integrating decision maker and patient perspectives

Planning problems in healthcare systems have received greater attention in the last decade, especially because of the concerns recently raised about the scattering of surgical interventions among a wide number of different facilities that can undermine the quality of the outcome due to the volume-outcome association. In this paper, an approach to plan the amount of surgical interventions that a facility has to perform to assure a low adjusted mortality rate is proposed. The approach explicitly takes into account the existing interaction among patients’ choices and decision makers’ planning decisions. The first objective of the proposed approach is to find a solution able to reach quality in health outcomes and patients’ adherence. The second objective is to investigate the difference among solutions that are identified as optimal by either only one of the actors’ perspective, i.e., decision makers and patients, or by considering both the perspectives simultaneously. Following these objectives, the proposed approach is applied to a case study on Italian colon cancer interventions performed in 2014. Results confirm a variation in the hospital planned volumes when considering patients’ behaviour together with the policy maker plan, especially due to personal preferences and lack of information about hospital quality