Mechanically assisted solid state synthesis of Mg2SnO4

Simultaneous TG?CDSC measurements have been used to study the solid state reaction in the system SnC₂O₄?C4MgCO₃·Mg(OH)₂·xH₂O (Sn:Mg?=?0.5). The results obtained with physically prepared mixture and with mixture mechanically activated by high-energy milling are compared. Synthesis of the compound Mg₂SnO₄ has been attempted starting from both type of mixture: Mg₂SnO₄ forms by annealing the activated mixture at temperatures between 850 and 1,000?°C while it can hardly be obtained from physical mixtures even by thermal treatment at temperature as high as 1,300?C1,350?°C. Mg₂SnO₄ prepared by annealing the activated mixture has been characterized by diffuse reflectance FT-IR spectroscopy, modulated temperature differential scanning calorimetry, scanning electron microscopy, and specific surface area measurements (B.E.T. method).     

Toxic mineral elements in Mytilus galloprovincialis from Sicilian coasts (Southern Italy)

Abstract

We assessed the relationship between V, Cr, Mn, Hg, As, Cd, Sn, Sb and Pb concentrations in Mytilus galloprovincialis samples from the coasts of Sicily and the expression of metallothioneins. Toxic mineral elements assessment was carried out by A.A. Spectrometry and ICP-MS. The metallothioneins expression was performed by q-PCR method. Low metals’ levels were found in the mussel samples examined, in comparison with what was reported in literature. The highest mean values of toxic mineral elements were found in Gela (Cr 0.178?±?0.03?mg/Kg, Mn 4.325?±?0.012?mg/Kg, As 3.706?±?0.009?mg/Kg, Sn 0.148?±?0.014?mg/Kg, Sb 0.009?±?0.004?mg/Kg e Pb 0.364?±?0.01?mg/Kg). Significant levels of Hg were found in samples from Catania (0.014?±?0.005?mg/Kg). Only vanadium and lead concentrations showed significant differences between sampling areas (p?<?0.05). Molecular analysis verified a basal expression of Mt1 and the absence of over-expression of Mt2, confirming the low mineral’s concentrations found in the samples examined.     

Tailoring “non conventional” ionic metallomesogens around an ortho-palladated fragment

A series of new ionic ortho-palladated mesogenic complexes [Pd(L)(4,4′-Rⁿ-bpy)][X] of unusual molecular shape have been prepared and characterised. The effect of slight structural changes on the molecular organization in the liquid crystalline phase is discussed in relation with their potential application as molecular materials.     

Well-posedness results and asymptotic behaviour for a phase transition model taking into account microscopic accelerations

We obtain an existence and uniqueness result to Frémond's phase transition model which take into account microscopic movements and accelerations. Moreover, the irreversible evolution of the phase variable is considered. Next, we perform an asymptotic analysis on the solution to the above problem, as the power of the microscopic acceleration forces goes to zero.     

Development of minimal fermentation media supplementation for ethanol production using two Saccharomyces cerevisiae strains

Ethanol production by fermentation is strongly dependent on media composition. Specific nutrients, such as trace elements, vitamins and nitrogen will affect the physiological state and, consequently, the fermentation performance of the micro-organism employed. The purpose of this study has been to assess the highest ethanol production by a minimal medium, instead of the more complex nutrients supplementation used during alcoholic fermentation. All fermentation tests were carried out using a microwell plate reader to monitor the processes. Two Saccharomyces cerevisiae strains (NCYC 2826 and NCYC 3445) were tested using three nitrogen sources, supplied with different vitamin and salts. The results show that solutions made of urea phosphate, KCl, MgSO₄·7H₂O, Ca-panthothenate, biotin allowed an ethanol yield of 22.9 and 23.4 g/L for strain NCYC 2826 and NCYC 3445, respectively, representing 90 and 92% of the theoretical yield. All tests were carried out using glucose as common reference carbon source.     

Metadynamics Simulations Rationalise the Conformational Effects Induced by N‐Methylation of RGD Cyclic Hexapeptides

We combined metadynamics, docking and molecular mechanics/generalised born surface area (MM/GBSA) re‐scoring methods to investigate the impact of single and multiple N‐methylation on a set of RGD cyclopeptides displaying different affinity for integrin αIIbβ3. We rationalised the conformational effects induced by N‐methylation and its interplay with receptor affinity, obtaining good agreement with experimental data. This approach can be exploited before entering time‐consuming and expensive synthesis and binding experiments.     

Turbulent time and length scale measurements in high-velocity open channel flows

In high-velocity open channel flows, the measurements of air–water flow properties are complicated by the strong interactions between the flow turbulence and the entrained air. In the present study, an advanced signal processing of traditional single- and dual-tip conductivity probe signals is developed to provide further details on the air–water turbulent level, time and length scales. The technique is applied to turbulent open channel flows on a stepped chute conducted in a large-size facility with flow Reynolds numbers ranging from 3.8E+5 to 7.1E+5. The air water flow properties presented some basic characteristics that were qualitatively and quantitatively similar to previous skimming flow studies. Some self-similar relationships were observed systematically at both macroscopic and microscopic levels. These included the distributions of void fraction, bubble count rate, interfacial velocity and turbulence level at a macroscopic scale, and the auto- and cross-correlation functions at the microscopic level. New correlation analyses yielded a characterisation of the large eddies advecting the bubbles. Basic results included the integral turbulent length and time scales. The turbulent length scales characterised some measure of the size of large vortical structures advecting air bubbles in the skimming flows, and the data were closely related to the characteristic air–water depth Y ₉₀. In the spray region, present results highlighted the existence of an upper spray region for C > 0.95–0.97 in which the distributions of droplet chord sizes and integral advection scales presented some marked differences with the rest of the flow.