Must obtained from Airén grapes was fermented in the presence of wood chips (4 and 7 g/L) of either French oak (from Vosges, central France, and Allier zones) or American oak. Fermentation yields were higher than in the control fermentations carried out in the absence of wood, and production of volatile substances during fermentation (alcohols, esters, and acetates) was also higher. The volatile substances that leached out of the wood were analyzed by GC-MS-SIR. The results showed that their concentrations depended on the type and amount of the oak; some of these substances were consumed in part by the yeasts during fermentation. A taste panel favorably assessed the wines produced by fermentation in the presence of oak chips, which retained part of the must original fruity aroma.

No abstract

The symmetry breaking of the loads of a matrix converter (MC) generated an imbalance that induced a quasiperiodic behavior at the input side of the MC.In addition, the load imbalance generated a negative-sequence current at the input side. This paper adopts the time-delayed feedback control (TDFC) to attenuate the quasiperiodic oscillation and the negative-sequence component caused by the symmetry breaking. The results indicate that the attenuation of the quasiperiodic behavior directly leads to a decrease of the negative-sequence current component. As a result, the TDFC improves the operation of the MC under unbalanced loads and part of the periodic symmetry is regained at the input side.

No abstract

No abstract