Major phenolic and volatile compounds and their influence on sensorial aspects in stem-contact fermentation winemaking of Primitivo red wines.

In red winemaking de-stemming is crucial since the stems contain polymeric phenolic compounds responsible for the astringency of wine. Wine such as Primitivo has low phenolic constituents and tannins and stems affect aroma, taste body and olfactory characteristics. The aim of the study was to evaluate the effects of presence of stems during fermentation on polyphenolic, volatile compounds and sensory characteristics of wine. Primitivo grapes vinified in presence of different percentage of stems: 100 % de-stemmed (D100), 75 % de-stemmed (D75) and 50 % de-stemmed (D50). Results confirmed that the wines vinified in presence of stems were higher in tannins, flavans, to vanillin and proanthocyanidins, colour intensity with lower anthocyanins. The presence of stems during fermentation conferred more structure and flavour to wines. They facilitated must aeration thus promoting synthesis of higher alcohols and ethyl esters by yeast. In particular, a higher content of hexan-1-ol, hex-3-en-1-ol and 2-phenyl ethanol in D50 and D75 gave the wines that suggest green grass, herb and floral. Wine from D75 seemed to be better than D50 in terms of volatile compounds as well as fruity, floral and balsamic components preserved, without any unpleasant taste of long chain fatty acids found in D50.

On the use of advanced numerical models for the evaluation of dosimetric parameters and the verification of exposure limits at workplaces.

With the next transposition of the 2004/40/EC Directive, employers will become responsible for the electromagnetic field level at the workplace. To make this task easier, the scientific community is compiling practical guidelines to be followed. This work aims at enriching such guidelines, especially for the dosimetric issues. More specifically, some critical aspects related to the application of numerical dosimetric techniques for the verification of the safety limit compliance have been highlighted. In particular, three different aspects have been considered: the dosimetric parameter dependence on the shape and the inner characterisation of the exposed subject as well as on the numerical algorithm used, and the correlation between reference limits and basic restriction. Results and discussions demonstrate how, even by using sophisticated numerical techniques, in some cases a complex interpretation of the result is mandatory.

Parallel FD-TD simulation of radiobase antennae.

The rigorous characterisation of the behaviour of a radiobase antenna for wireless communication systems is a hot topic both for antenna or communication system design and for radioprotection-hazard reasons. Such a characterisation deserves a numerical solution, and the use of a finite-difference time-domain (FD-TD) approach is an attractive candidate. Unfortunately, it has strong memory and CPU-time requirements. Numerical complexity can be successfully afforded by using parallel computing. The parallel implementation of the FD-TD code, individuating the theoretical lower bound for its parallel execution time are discussed and the findings achieved on the APE/Quadrics massively parallel systems are presented. Results obtained from the simulation of actual radiobase antennae, clearly demonstrate that massively parallel processing is a viable approach to solving electromagnetic problems, allowing the simulation of radiating devices which could not be modelled through conventional computing systems. The tests showed a sustained computational speed equal to 17% of the theoretical maximum.