Evolution of the colour,antioxidant activity and polyphenols in unusually aged Sherry wines

The present paper reports the results of a study monitoring several key analytical parameters in a set of aged samples of vintages from 1999 back to 1935. The analysed parameters were: colour, antioxidant activity, low molecular weight phenolics, index of total polyphenols and SO₂ content.     

A Simulation Environment for an Augmented Global Navigation Satellite System Assisted Autonomous Robotic Lawn-Mower

This paper presents the software architecture that was developed to evaluate the performance of different Global Navigation Satellite Systems (GNSSs) and Satellite/Ground-Based Augmentation Systems for the localization and navigation of an autonomous robotic lawn-mower. In particular, a complete simulation environment has been developed to analyse the system performance obtained by adopting the future European GNSSs when GALILEO will be fully operative. Moreover, this tool has been adopted in the development phase of a precise GNSS-based localization system and developed within the MOW-BY-SAT project, an FP7 project funded by the European Commission; this architecture relies on an innovative algorithm that allows for a Real Time Kinematic localization system, while requiring only a pair of low-cost GPS receivers. The results show the validity of the developed localization and control architecture and the potential of the future European GALILEO system.     

Role of 2‐hydroxyethyl end group on the thermal degradation of poly(ethylene terephthalate) and reactive melt mixing of poly(ethylene terephthalate)/poly(ethylene naphthalate) blends

In an attempt to minimize the acetaldehyde formation at the processing temperatures (280–300°C) and the outer–inner transesterification reactions in the poly (ethylene terephthalate) (PET)–poly(ethylene naphthalate) (PEN) melt‐mixed blends, the hydroxyl chain ends of PET were capped using benzoyl chloride. The thermal characterization of the melt‐mixed PET–PEN blends at 300°C, as well as that of the corresponding homopolymers, was performed. Degradations were carried out under dynamic heating and isothermal conditions in both flowing nitrogen and static air atmosphere. The initial decomposition temperatures (T_i) were determined to draw useful information about the overall thermal stability of the studied compounds. Also, the glass transition temperature (T_g) was determined by finding data, indicating that the end‐capped copolymers showed a higher degradation stability compared to the unmodified PET and, when blended with PEN, seemed to be efficient in slowing the kinetic of transesterification leading to, for a finite time, the formation of block copolymers, as determined by ¹H‐NMR analysis. This is strong and direct evidence that the end‐capping of the ? OH chain ends influences the mechanism and the kinetic of transesterification. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Catalytic combustion of volatile organic compounds on gold/iron oxide catalysts

Catalytic oxidation of 2-propanol, methanol, ethanol, acetone and toluene was investigated on coprecipitated Au/Fe₂O₃ catalysts in the presence of excess of oxygen. Gold catalysts have been found to be very active in the oxidation of tested volatile organic compounds (VOCs). The high activity of these systems has been related to the capacity of highly dispersed gold to weaken the Fe–O bond thus increasing the mobility of the lattice oxygen which is involved in the VOCs oxidation probably through a Mars–van Krevelen reaction mechanism.     

Recovery of Wine-Must Aroma Compounds by Supercritical CO2

The fractionation of wine musts (the fermentation broth that leads from grape juice to wine) of highly aromatic grape varieties was performed with supercritical carbon dioxide at pressures between 11 and 18 MPa and temperatures between 308 and 318 K. Different configurations of the separation devices were tested after the extraction step to improve the fractionation process. Headspace chromatography and Karl Fisher analyses were used to measure the composition of the extracts. A significant enrichment of the supercritical extracts on aromatic compounds was observed. The recovery of the aromatic compounds from the high pressure solvent stream poses technical problems that must be solved before the process can be feasible in an industrial scale.     

Combined MALDI-TOF MS and NMR characterization of copoly(arylen ether sulphone)s

The synthesis and the chemical characterization of some novel random copolyethersulphones of the type P(ESES-co-EES) (Polyethersulphone-ethersulphone:Polyetherethersulphone), is reported. The ESES:EES molar ratio was varied from 80:20 to 20:80 and all the copolymers were terminated with reactive amino groups, and then were fully characterized through (¹H and ¹³C)-NMR and MALDI-TOF MS analysis to confirm their chemical structures and chemical compositions. End chains were revealed by these techniques. Contrary to chlorine-ended copolymers, oligomers terminated with hydroxyl groups were revealed in the amine-ended copolymers, indicating that transetherification reactions occur during the capping reaction with m-aminophenol. Cycles were also revealed by MALDI-TOF MS, that revealed also some unexpected end chains may be formed for the impurities in the feed. The glass transition temperatures of the copolymers have been determined by differential scanning calorimetry (DSC).     

Antioxidant activity of Brandy de Jerez and other aged distillates,and correlation with their polyphenolic content

The antioxidant activities (AA) of commercial sherry brandies (Solera, Solera Reserva and Solera Gran Reserva) and samples obtained from an experimental ageing system were measured. In the dynamic ageing system, the data show that the casks containing the youngest distillate become exhausted over time. For experimental and commercial brandies, antioxidant activity and polyphenolic content both increase with increasing age, so the correlation between the two parameters was analysed. It is concluded that there is a significant relationship between them; however, it seems that some non-phenolic compounds could also contribute to the antioxidant activity. The results revealed certain differences between commercial and experimental sherry brandies, and these differences could be due to the addition of caramel colouring. Several other commercial aged distillates of various different geographical origins (Cognacs, Armagnacs, and Spanish, French and South African brandies) were studied, and their antioxidant power was compared with that of the three categories of Brandy de Jerez. It was found that Solera Gran Reserva sherry brandies show the highest antioxidant activity of all the products considered.     

Thermohygrometric and mechanical behaviour of concrete using damage models

A numerical formulation to analyse thermohygrometrically and mechanically coupled fields in concrete is presented. One of the main applications concerns the creep and shrinkage of concrete, wherein the transient hygrothermal effects are related to the mechanical behaviour and take account of geometrical non-linearities and anisotropic damage coupled with viscosity. The stress-strain relationship is represented by an integral equation. This procedure is implemented in a finite element code in order to analyse 2-D and 3-D structures of any shape, and the results regarding the numerical simulation of the creep and shrinkage in a concrete cylinder are presented.