13,159 research outputs found
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
- …