324,167 research outputs found
Il pianto nei primi tre mesi di vita: uno studio italiano
No full textQuesto studio si pone come obiettivo quello di individuare, in una popolazione non-clinica da 0 a tre mesi, le principali caratteristiche del pianto, la sua durata, i pattern quotidiani, le risposte dei genitori, la percezione del pianto, i significati ad esso attribuiti e le strategie maggiormente utilizzate per farvi fronte. Il nostro campione è composto da 60 bambini e dalle loro madri. I neonati (31 femmine e 29 maschi) sani e a termine, sono suddivisi in 5 coorti di 12 soggetti ciascuna, rispettivamente di 2, 4, 6, 8 e 10 settimane di età. Per la raccolta dei dati è stato utilizzato un questionario costruito ad hoc che è stato affiancato alla compilazione di un diario quotidiano sul pianto del bambino i cui dati sono già stati precedentemente presentati e discussi (Mazzotti, Bonichini, Axia, 2003). I risultati evidenziano che le quantità di pianto riportate nel questionario corrispondono a quelle calcolate attraverso l’elaborazione del diario e seguono un pattern evolutivo come quello riportato in letteratura che prevede un andamento crescente fino alle 4 settimane seguito da un graduale decremento delle quantità di pianto quotidiano. Viene inoltre confermata la presenza del picco di pianto serale riportato in letteratura e nello studio italiano precedente
Le scene di battaglia dell'Iliade
No full textThe review (Oliver Hellmann, Die Schlachtszenen der Ilias: das Bild des Dichters vom Kampf in der Heroenzeit, Franz Steiner Verlag, Stuttgart 2000) focuses on Hellmann?s method in the analysis of the connection between war and heroic society and in the study of the conditions of the recruitment and fighting (formation and organization of troops, tactics, individual duel and mass-attack), although the author admits that Homer?s Iliad is an artistic work and so he gives up the idea of offering a precise and consistent historical description on the grounds of Homeric poetry
Stratigraphic interpretation of amplitude processed seismic data: a case history in the Lombardian Plain
No full text
Joint estimation of AVO and kinematic parameters
No full textConventional amplitude-versus-offset (AVO) analysis such as linear fitting of isotime samples after NMO correction does not give reliable results in the presence of interfering reflections or velocity errors. For this reason we propose a new method that is able to remove interference effects on the AVO of the target reflection and minimize the effects of residual moveout. The method is based on the minimization of the difference between observed data and a model that includes theoretical descriptions of the AVO and traveltimes. This minimization is carried out jointly with respect to AVO and minematic parameters (velocities and traveltimes) and requires the a priori knowledge of the propagating wavelet. The kinematic parameters are given by the NMO equation extended to the fourth-order term and the AVO is described as a linear combination of a set of orthogonal functions. The AVO functions are derived from a statistical model of reflection amplitude in the presence of velocity error. Applications to synthetic and real data demonstrate the ability of the method to attenuate distortion effects on the AVO of the primary reflection by interfering coherent noise. The real data example pertains to a marine case where the primary event is contaminated by multiple reflections generated in the water layer and by another event, reflected from an interface deeper than the target, that merges with the examined reflections at the far-offsets. This causes a subtle tuning that distorts the AVO of the target. Our method attenuates the effects of the multiples and discriminates the 'double event' nature of the target reflection at the far-offsets
The effect of CO2 and salinity on olivine dissolution kinetics at 120 {ring operator} C
No full textThis paper reports the results of an experimental study on the dissolution kinetics of olivine (Mg1.82 Fe0.18 SiO4) at operating conditions relevant to the mineral carbonation process for the permanent storage of CO2. In particular, we investigated the effects of CO2 fugacity (fCO2) and of salinity on the kinetics of olivine dissolution, which is assumed to be the rate-limiting step of the overall carbonation process. Dissolution experiments were carried out at 120 {ring operator} C in a stirred flow-through reactor. Different pH values (between 3 and 8) and solution compositions were investigated by varying fCO2 and by dosing LiOH (for pH control), NaCl, and NaNO3. The specific dissolution rate values, r, were estimated from the experimental data using a population balance equation (PBE) model coupled with a mass balance equation. The logarithms of the obtained r values were regressed with a linear model as a function of pH and compared to the model reported earlier [Hänchen, M., Krevor, S., Mazzotti, M., Lackner, K.S., 2007. Validation of a population balance model for olivine dissolution. Chem. Eng. Sci. 62, 6412-6422] for experiments with neither CO2 nor salts. Our results confirm that, at a given temperature, olivine dissolution kinetics depends on pH only, and that fCO2 and the concentrations of NaCl and NaNO3 affect it through their effect on pH. © 2009 Elsevier Ltd. All rights reserved
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