Search results for "Maran"
showing 10 items of 66 documents
CFD Study of an Innovative Catamaran with Asymmetrical Hulls
2013
The purpose of this paper is the study of the shape of catamaran with asymmetrical hulls by both experimental and numerical viewpoint. The experimental study is based on the towing tank tests on a catamaran hulls shape obtained from previous works, showing that the wave resistance is very low produces a lower energy loss and a greater effectiveness. The hulls shape is optimized by the CFD application by force of commercial software, which shows that the reduction of wasted energy is very sensitive to make some changes; in particular three different width of the catamaran are tested and their performances are compared.
ANALISI CFD DELLE PRESTAZIONI DI UN CATAMARANO CON SCAFI ASIMMETRICI DOTATO DI SOSTENTAMENTO IDRODINAMICO
2010
Nel presente lavoro è proposto uno studio di ottimizzazione su di un catamarano a scafi asimmetrici con murate piane esterne, grazie al progetto di due alettoni posizionati trasversalmente alla direzione del moto al di sotto del piano di galleggiamento ai quali è affidato il sostentamento idrodinamico dell’intero catamarano. L’obiettivo finale dello studio è quello di ridurre la resistenza totale all’avanzamento del catamarano dopo aver progettato in maniera opportuna le due appendici alari. Le analisi CFD, sia del catamarano senza alettoni che del catamarano con agli alettoni, hanno dato la possibilità di operare un confronto tra i due catamarani evidenziando un beneficio del 38% in termin…
Salvadore Cammarano, Calisto Bassi e «l’orditura del libretto» di Alzira
2023
On August 12, 1845, Alzira, Giuseppe Verdi’s eighth opera, made its debut at the Teatro San Carlo in Naples. Against the composer’s own expecta-tions, the opera—to a libretto by Salvadore Cammarano based on Vol-taire—proved a failure, getting only about 20 performances. Even subse-quent stagings (13 between 1845 and 1858) met with lukewarm reception. A year after the first performance, on August 17, 1846, Calisto Bassi, an experienced librettist and translator, sent some comments on the libretto and proposals for improvements to the publisher Tito Ricordi. In this con-tribution, I aim to discuss this hitherto unpublished letter as well as to re-flect on the dramaturgy of this opera and the …
New and little known species of the genus Parapholidoptera Maran (Insecta, Orthoptera)
2009
Material of species of the genus Parapholidoptera Maran is presented. New records of P. noxia (Ramme) are reported from Georgia, P. georgiae sp. n. from Georgia and P. kalashiani sp. n. from Armenia are described. P. syriaca is newly reported from Lebanon. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Suitability of the VOF Approach to Model an Electrogenerated Bubble with Marangoni Micro-Convection Flow
2022
When a hydrogen or oxygen bubble is created on the surface of an electrode, a micro-convective vortex flow due to the Marangoni effect is generated at the bottom of the bubble in contact with the electrode. In order to study such a phenomenon numerically, it is necessary to be able to simulate the surface tension variations along with a liquid-gas interface, to integrate the mass transfer across the interface from the dissolved species present in the electrolyte to the gas phase, and to take into account the moving contact line. Eulerian methods seem to have the potential to solve this modeling. However, the use of the continuous surface force (CSF) model in the volume of fluid (VOF) framew…
Herbicide resistance in France
1990
* INRA URD BP 86510 21065 Dijon cedex (FRA); International audience
Des mauvaises herbes a bien connaitre pour un desherbage efficace
1986
National audience
Phytotoxic effects of Lantana camara, Eucalyptus camaldulensis and Eriocephalus africanus essential oils in weeds of Mediterranean summer crops
2009
Abstract The essential oil composition of Lantana camara , Eucalyptus camaldulensis and Eriocephalus africanus was analyzed by means of GC and GC–MS and bioassayed in order to determine their activity against Amaranthus hybridus and Portulaca oleracea . E. camaldulensis essential oil, with spathulenol as the main compound, was the most effective, completely inhibiting germination and seedling growth on both weeds. The essential oil of E. africanus , rich in artemisia ketone, showed activity similar to that of E. camaldulensis on A. hybridus , but it was not so effective against P. oleracea , and L. camara essential oil, with high percentages in sesquiterpene hydrocarbons, also showed higher…
Floral synorganization and its influence on mechanical isolation and autogamy in Marantaceae
2012
The flowers of Marantaceae (∼ 550 species) exhibit a highly derived pollination mechanism within Zingiberales, with a rapid and irreversible style movement based on a close synorganization of different floral parts. Given the complexity of the structure, we assume that little variation is possible if functionality is to be maintained. To test this, we investigated how much floral diversity exists in the clade and whether this diversity potentially influences the breeding system and placement of pollen on the pollinator. Flowers of 66 species covering the five major phylogenetic clades of the family were analysed. All species are similar in their basic flower construction: the fleshy stamino…
A dammarane-type saponin from the roots of Ampelozizyphus amazonicus.
1993
A new C31 dammarane-type triterpenoid saponin has been isolated from the roots of Ampelozizyphus amazonicus. Its structure was elucidated to be ampelozigenin-15 alpha-O-acetyl- 3-O-alpha-L-rhamnopyranosyl-(1--2)-beta-D-glucopyranoside by 1D and 2D NMR spectroscopic methods, and by chemical transformations. Ampelozigenin is a novel triterpene, (20R,22R)-16 beta,22:16 alpha, 30-diepoxydammar-24(24')- methylene-3 beta, 15 alpha, 20-triol.