Production de vins mousseux a partir de "Vinhos Verdes" blancs monovarietaux

On a fait l'étude comparative de vins mousseux élaborés à partir de vins de base issus de cinq cépages recommandés pour la Région: Loureiro, Trajadura, Avesso, Pedernã et Azal blanc, en ce qui concerne les propriétés organoleptiques. Les vins de base ont été produits selon le processus utilisé dans la Région -égrappage, pressurage, débourbage et fermentation alcoolique-, ayant été soumis aussi à une fermentation malolactique. La prise de mousse a été effectuée en bouteille, avec des levures immobilisées en billes d'alginate, pendant cinq mois à 14 °C. Les propriétés sensorielles des vins ont été évaluées en utilisant des fiches classificatrices et descriptives, par une chambre de neuf dégustateurs expérimentés. Le traitement statistique des résultats, effectué par le logiciel SPSS, a été fait en recourrant à l'analyse de variance. On a trouvé quelques différences parmi les cinq vins mousseux surtout en ce qui concerne l'aspect du cordon et l'arôme. Cependant, tous ces vins ont obtenu des classifications globales au-dessus de l'acceptable, atteignant parfois l'excellent. Ces résultats préliminaires ainsi obtenus, basés sur les caractéristiques organoleptiques, suggèrent la possibilité d'obtenir des vins mousseux de qualité à partir des cépages de "Vinho Verde"

Modeling of chemical wear in ferrous alloys/silicon nitride contacts during high speed cutting

The wear resistance of SisN4 in machining of iron alloys can be surprisingly low due to chemical affinity for dissolution in the metal. This limits the use of SisN4 inserts in high speed machining of steels, while Si3N4 retains the best performance of all cutting materials in turning of grey cast iron, a different ferrous alloy. The chemical wear of several ceramics has been investigated on the basis of dissolution in pure iron by Kramer and Suh. Nevertheless, the influence of alloy elements was not studied. In the present work, solid solution thermodynamics is applied to predict chemical wear of S&N4 by setting the influence of interaction coefficients of the alloy elements in the Henrian activity of Si and N in austenite. The model predicts the relative order of magnitude of the crater wear of SisN4 inserts in machining of tool steels, carbon steels and grey cast iron

Synergistic effect of Glomus intraradices and Frankia spp. on the growth and stress recovery of Alnus glutinosa in an alkaline anthropogenic sediment

The presence of actinorhizas and arbuscular mycorrhizas may reduce plant stresses caused by adverse soil conditions. A greenhouse experiment was conducted using a sediment with a high pH, resulting from the disposal of waste originated at an acetylene and polyvinylchloride factory, in which Black alder (Alnus glutinosa) seedlings were inoculated either with Glomus intraradices BEG163 (originally isolated from the same sediment), Frankia spp. or both symbionts. After a 6-month growth period, plants inoculated with both symbionts had significantly greater leaf area, shoot height and total biomass when compared with the uninoculated control, the Frankia spp. and the G. intraradices treatments alone. In dual inoculated plants the N and P leaf content was significantly increased. A defoliation experiment was performed to evaluate the stress recovery of A. glutinosa and plants inoculated with both symbionts had a faster leaf regrowth and produced greater numbers of leaves. The dual inoculation resulted in greater numbers of and larger root nodules than when inoculated with Frankia spp. alone. The length and NADH diaphorase activity of the extraradical mycelium of G. intraradices was also significantly greater when dual inoculation was performed. The inoculation with Frankia spp. alone was shown to improve A. glutinosa growth, whereas G. intraradices alone had no positive effect under these environmental conditions. However, when the two symbionts were inoculated together a synergistic effect was observed resulting in a greater benefit for the plants and for both symbionts. The relevance of these findings for the phytorestoration of anthropogenic stressed sediments with high pH is discussed

Studies on the diversity of arbuscular mycorrhizal fungi and the efficacy of two native isolates in a highly alkaline anthropogenic sediment

A field survey of the arbuscular mycorrhizal status of herbaceous plant species was conducted in a highly alkaline anthropogenic sediment resulting from the disposal of waste from an acetylene and polyvinyl chloride factory. Most plant species found at the site were mycorrhizal and the dominant mycotrophic plant species was Conyza bilbaoana. Fungal species richness was assessed by identification of spores extracted from the sediment and from continuously propagated trap pot cultures. All of the six species of arbuscular mycorrhizal fungi (AMF) found were from the genus Glomus. Glomus intraradices and G. mosseae were found in field-collected sediment samples and also occurred most frequently in trap cultures. To test the symbiotic effectiveness of these two fungi, seedlings of C. bilbaoana were inoculated with either native G. intraradices BEG163 or G. mosseae BEG198 and non-native G. intraradices BEG75 or G. mosseae BEG25 isolates in sterile and non-sterile sediment collected from the study site. All four isolates were able to colonise C. bilbaoana. However, AMF native to the target sediments were generally more effective than the non-native fungi in promoting plant establishment and growth under highly alkaline conditions. The non-native G. intraradices was, however, more effective than the non-native G. mosseae. The results of this study suggest the use of adapted AMF as inoculants for phytorestoration of alkaline anthropogenic-stressed sediments

Hole concentration in a diluted ferromagnetic semiconductor

We consider a mean-field approach to the hole-mediated ferromagnetism in III-V Mn-based semiconductor compounds to discuss the dependence of the hole density on that of Mn sites in Ga_{1-x}Mn_xAs. The hole concentration, p, as a function of the fraction of Mn sites, x, is parametrized in terms of the product m*J_{pd}^2 (where m* is the hole effective mass and J_{pd} is the Kondo-like hole/local-moment coupling), and the critical temperature Tc. By using experimental data for these quantities, we have established the dependence of the hole concentration with x, which can be associated with the occurrence of a reentrant metal-insulator transition taking place in the hole gas. We also calculate the dependence of the Mn magnetization with x, for different temperatures (T), and found that as T increases, the width of the composition-dependent magnetization decreases drammatically, and that the magnetization maxima also decreases, indicating the need for quality-control of Mn-doping composition in diluted magnetic semiconductor devices.Comment: 4 pages, 3 figures, RevTeX 3; Fig. 1 changed, new references adde

Minimizing airport peaks problem by improving airline operations performance through an agent based system

Airports are important infra-structures for the air transportationbusiness. One of the major operational constraints is the peak of passengers inspecific periods of time. Airline companies take into consideration the airportcapacity when building the airline schedule and, because of that, the executionof the airline operational plan can contribute to improve or avoid airport peakproblems. The Airline Operations Control Center (AOCC) tries to solveunexpected problems that might occur during the airline operation. Problemsrelated to aircrafts, crewmembers and passengers are common and the actionstowards the solution of these problems are usually known as operationsrecovery. In this paper we propose a way of measuring the AOCC performancethat takes into consideration the relation that exists between airline scheduleand airport peaks. The implementation of a Distributed Multi-Agent System(MAS) representing the existing roles in an AOCC, is presented. We show thatthe MAS contributes to minimize airport peaks without increasing theoperational costs of the airlines