University of Palermo

About: University of Palermo is a education organization based out in Palermo, Italy. It is known for research contribution in the topics: Population & Cancer. The organization has 15621 authors who have published 40250 publications receiving 964384 citations. The organization is also known as: Università degli Studi di Palermo & Universita degli Studi di Palermo.

Fibropolycystic Liver Disease: CT and MR Imaging Findings

Abstract: Fibropolycystic liver disease encompasses a spectrum of related lesions of the liver and biliary tract that are caused by abnormal embryologic development of the ductal plates. These lesions (congenital hepatic fibrosis, biliary hamartomas, autosomal dominant polycystic disease, Caroli disease, choledochal cysts) can be clinically silent or can cause signs and symptoms such as cholangitis, portal hypertension, gastrointestinal bleeding, infections, and space-occupying masses. The different types of fibropolycystic liver disease demonstrate characteristic findings at computed tomography (CT) and magnetic resonance (MR) imaging. Patients with congenital hepatic fibrosis typically have imaging evidence of liver morphologic abnormalities, varices, splenomegaly, renal lesions, and other associated ductal plate abnormalities. Biliary hamartomas usually manifest as multiple cysts that are nearly uniform in size and measure up to 15 mm in diameter. Autosomal dominant polycystic disease typically manifests as an enlarged and diffusely cystic liver. In Caroli disease, cystic or fusiform dilatation of the intrahepatic ducts is seen, as well as the "central dot sign," which corresponds to a portal vein branch protruding into the lumen of a dilated bile duct. Choledochal cyst manifests as a fusiform or cystic dilatation of the extrahepatic bile duct. Awareness of these CT and MR imaging features is essential in detecting and differentiating between various fibropolycystic liver diseases and can assist in proper management.

Straw mulch as a sustainable solution to decrease runoff and erosion in glyphosate-treated clementine plantations in Eastern Spain. An assessment using rainfall simulation experiments

Abstract: In many Mediterranean areas, citrus orchards exhibit high soil loss rates because of the expansion of drip irrigation that allows cultivation on sloping terrain and the widespread use of glyphosate. To mitigate these non-sustainable soil losses, straw mulch could be applied as an efficient solution but this has been poorly studied. Therefore, the main goal of this paper was to assess the use of straw mulch as a tool to reduce soil losses in clementine plantations, which can be considered representative of a typical Mediterranean citrus orchard. A total of 40 rainfall simulation experiments were carried out on 20 pairs of neighbouring bare and mulched plots. Each experiment involved applying 38.8 mm of rain at a constant rate over 1 h to a circular plot of 0.28 m2 circular plots. The results showed that a cover of 50% of straw (60 g m−2) was able to delay the time to ponding from 32 to 52 s and the time to runoff initiation from 57 to 129 s. Also, the mulching reduced the runoff coefficient from 65.6 to 50.5%. The effect on sediment transport was even more pronounced, as the straw mulch reduced the sediment concentration from 16.7 g l−1 to 3.6 g l−1 and the soil erosion rates from 439 g to 73 g. Our results indicated that mulching can be used as a useful management practice to control soil erosion rates due to the immediate effect on high soil detachment rate and runoff initiation reduction in conventional clementine orchards on sloping land, by slowing down runoff initiation and by reducing runoff generation and, especially, sediment losses. We indirectly concluded that straw mulch is also a sustainable solution in glyphosate-treated citrus plantations.

Phase Equilibria of Lattice Polymers from Histogram Reweighting Monte Carlo Simulations

Abstract: Histogram reweighting Monte Carlo simulations were used to obtain polymer/solvent phase diagrams for lattice homopolymers of chain lengths up to r = 1000 monomers. The simulation technique was based on performing a series of grand canonical Monte Carlo calculations for a small number of state points and combining the results to obtain the phase behavior of a system over a range of temperatures and densities. Critical parameters were determined from mixed-field finite-size scaling concepts by matching the order parameter distribution near the critical point to the distribution for the three-dimensional Ising universality class. Calculations for the simple cubic lattice (coordination number z = 6) and for a high coordination number version of the same lattice (z = 26) were performed for chain lengths significantly longer than those in previous simulation studies. The critical temperature was found to scale with a chain length following the Flory−Huggins functional form. For the z = 6 lattice, the extrapolat...

Numerical simulation of fatigue-driven delamination using interface elements

Abstract: This paper presents a computational technique for the prediction of fatigue-driven delamination growth in composite materials. The interface element, which has been extensively applied to predict delamination growth due to static loading, has been modified to incorporate the effects of cyclic loading. Using a damage mechanics formulation, the constitutive law for the interface element has been extended by incorporating a modified version of a continuum fatigue damage model. The paper presents details of the fatigue degradation strategy and examples of the predicted fatigue delamination growth in mode I, mode II and mixed mode I/II are presented to demonstrate that the numerical model mimics the Paris law behaviour usually observed in experimental testing. Copyright © 2005 John Wiley & Sons, Ltd.

Experimental Crystallization of a High-K Arc Basalt: the Golden Pumice, Stromboli Volcano (Italy)

Abstract: The near-liquidus crystallization of a high-K basalt (PST-9 golden pumice, 49·4 wt % SiO2, 1·85 wt % K2O, 7·96 wt % MgO) from the present-day activity of Stromboli (Aeolian Islands, Italy) has been experimentally investigated between 1050 and 1175°C, at pressures from 50 to 400 MPa, for melt H2O concentrations between 1·2 and 5·5 wt % and {Delta}NNO ranging from –0·07 to +2·32. A drop-quench device was systematically used. AuPd alloys were used as containers in most cases, resulting in an average Fe loss of 13% for the 34 charges studied. Major crystallizing phases include clinopyroxene, olivine and plagioclase. Fe–Ti oxide was encountered in a few charges. Clinopyroxene is the liquidus phase at 400 MPa down to at least 200 MPa, followed by olivine and plagioclase. The compositions of all major phases and glass vary systematically with the proportion of crystals. Ca in clinopyroxene sensitively depends on the H2O concentration of the coexisting melt, and clinopyroxene Mg-number shows a weak negative correlation with {Delta}NNO. The experimental data allow the liquidus surface of PST-9 to be defined. When used in combination with melt inclusion data, a consistent set of pre-eruptive pressures (100–270 MPa), temperatures (1140–1160°C) and melt H2O concentrations is obtained. Near-liquidus phase equilibria and clinopyroxene Ca contents require melt H2O concentrations <2·7–3·6 and 3 ± 1 wt %, respectively, overlapping with the maximum frequency of glass inclusion data (2·5–2·7 wt % H2O). For olivine to crystallize close to the liquidus, pressures close to 200 MPa are needed. Redox conditions around {Delta}NNO = +0·5 are inferred from clinopyroxene compositions. The determined pre-eruptive parameters refer to the storage region of golden pumice melts, which is located at a depth of around 7·5 km, within the metamorphic arc crust. Golden pumice melts ascending from their storage zone along an adiabat will not experience crystallization on their way to the surface.