325,060 research outputs found
Considerazioni Tecnico-Economiche sull’Applicazione dell’Annesso J dell’EC3 nella Progettazione di Telai in Acciaio
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Vlasov-Poisson: The waterbag method revisited
No full textWe revisit, with a view to refinement and generalization, the elegant waterbag method for the numerical treatment of Vlasov-Poisson equations. In this method, the phase space is decomposed into patches of constant density, and by exploiting Liouville's theorem, the dynamics is reduced to the evolution of the boundary of these patches (waterbags). We follow the boundary using an adaptive, oriented polygon, and recover the force by circulating along this polygon. We discuss sampling of initial conditions with a set of oriented isocontours, and propose a new refinement procedure for accurate rendering of the stretching and folding polygon. Time evolution is naturally undertaken with symplectic algorithms. Tools, initially developed for systems of self-gravitating sheets, generalize naturally to spherically symmetric systems. We conclude with examples of both cases. © 2007 Elsevier B.V. All rights reserved.CHANNELL PJ, 1990, NONLINEARITY, V3, P231, DOI 10.1088-0951-7715-3-2-001; CHENG CZ, 1976, J COMPUT PHYS, V22, P330, DOI 10.1016-0021-9991(76)90053-X; CUPERMAN S, 1971, ASTROPHYS SPACE SCI, V13, P411, DOI 10.1007-BF00649170; dePackh D.C., 1962, Journal of Electronics and Control, V13; FUJIWARA T, 1983, PUBL ASTRON SOC JPN, V35, P547; Henon M., 1964, Annales d'Astrophysique, V27; HOHL F, 1967, ASTROPHYS J, V147, P1164, DOI 10.1086-149106; JANIN G, 1971, ASTRON ASTROPHYS, V11, P188; Lorensen W. E., 1987, COMPUT GRAPH, V21, P163, DOI DOI 10.1145-37402.37422; ROBERTS KV, 1967, PHYS REV LETT, V19, P297, DOI 10.1103-PhysRevLett.19.297; Spitzer L, 1942, ASTROPHYS J, V95, P329, DOI 10.1086-144407; Toro E. F, 1999, RIEMANN SOLVERS NUME; Wisdom J., 1996, FIELDS I COMMUNICATI, V10, P217; WISDOM J, 1991, ASTRON J, V102, P1528, DOI 10.1086-115978; YOSHIDA H, 1990, PHYS LETT A, V150, P262, DOI 10.1016-0375-9601(90)90092-311
Un paese alla ricerca della felicità. L’Unione Sovietica negli anni della collettivizzazione: letteratura, cinema e iconografie.
No full textQuelques observations sur les stratégies de la compilation d’Eugippe
No full textL'article traite de la compilation d’extraits augustiniens connue sous le titre d’Excerpta ex operibus sancti Augustini, due à l’initiative d’Eugippe, abbé du monastère de Saint-Séverin près du Castellum Lucullanum au début du VIe siècle. Il en examine, d’une part, les problématiques du point de vue philologique et historico-textuel, et d’autre part, la structure de l’œuvre, formulant une hypothèse sur les noyaux thématiques fondamentaux qui pourraient avoir motivé la compilation elle-même
S. Prandi, I gesti di Virgilio,"Giornale storico della letteratura italiana", 1995, CLXXII, 557
No full textSolid state interaction of steroids with calixarenes. I. A preliminary FTIR and DSC study on 4-en-3-keto-steroids
No full textBoth DSC and FTIR studies indicate that co-grinding and co-precipitation cause steroids to interact with calixarenes. This interaction leads to breaking of the crystal lattice of the steroids, dispersion of the steroidal carbonyls in a hydrophobic environment and formation of hydrogen bonds between steroidal and calixarene hydroxyls. This interaction seems to be specific, depending on the structure of the calixarene and of the steroid involved. It is reasonable to assume that inclusion complexes are formed
Experimental and analytical investigation of PBO FRCM-concrete bond behavior using direct and indirect shear test set-ups
No full textExternally bonded reinforcement (EBR) represents an effective solution to strengthen existing reinforced concrete (RC) members. EBR comprising fiber-reinforced cementitious matrix (FRCM) has been increasingly adopted due to some advantages with respect to the more diffused fiber-reinforced polymer (FRP). Externally bonded FRCM often reported debonding failure at the matrix-fiber interface. In the literature, the matrix-fiber bond behavior was studied using mostly single- and double-lap direct shear (DS) tests. An alternative is represented by modified beam (MB) test set-ups. In this paper, a MB test set-up is adopted to study the effect of flexural deflection on the bond behavior of a polyparaphenylene benzobisoxazole (PBO) FRCM composite bonded to a concrete substrate. Two different MB test layouts are investigated and the results obtained are analyzed and compared with those of corresponding DS tests with the same PBO FRCM. Then, an analytical model able to describe the results of both DS and MB tests accounting for the presence of stresses normal to the matrix-fiber interface is proposed. The experimental results and analysis presented in this paper help to clarify the influence of the test set-up on the bond behavior of FRCM composites, which represents a key parameter for the design of FRCM EBR
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