1,512 research outputs found
Prestation indue et enrichissement in?quitable : ? propos de deux quasi-contrats dans l\u27avant-projet d\u27ordonnance r?formant le droit fran?ais des obligations
No full textLes quasi-contrats constituent une institution juridique discr?te mais durable en m?me temps que passionnante. Pourtant, dans le cadre de la r?forme du droit des obligations, peu d?analyses doctrinales ont port? sur cette mati?re. La pr?sente ?tude consiste alors en une analyse des dispositions relatives ? ce qui est appel? le ? paiement de l?indu ? et ? l?enrichissement injustifi? ? dans le dernier ?tat du projet de r?forme.
D?une mani?re g?n?rale, l?heure n?est pas ? la refonte totale des quasi-contrats, si tant est qu?elle e?t ?t? n?cessaire. Par cons?quent, nous proposons principalement des modifications d?ordre terminologique, en axant notre analyse sur la s?mantique et sur la linguistique juridique en g?n?ral
Triterpenoid saponins of Bellis perennis
No full textTen saponins have been isolated from the deacylated saponin mixture of Bellis perennis L. The structures of these saponins can be divided into two groups that show differences both in the aglycone and the carbohydrate moieties bound at C-28. The first group consists of glycosides of polygalacic acid with tri- or tetrasaccharide moieties consisting mainly of deoxyhexoses and a second group of glycosides of bayogenin or asterogenic acid which possess glucose as major carbohydrate moiety and one xylose or rharnnose unit. From the most polar fraction of the alkaline hydrolysate obtained from the underground parts of Bellis perennis one saponin possessing only glucose residues has been obtained. On the basis of a sugar methylation analysis and NMR spectral data, the structure was established as 3-O-ß-D-glucopyranosyl-2ß,3ß,23-trihydroxyolean-12-en-28-oic acid 28-O-ß-D-glucoyranosyl-(1→2)-[ß-D-glucopyranosyl(1→6)]-ß-D-glucopyranoside
Recensione di A. CORSANO, Tommaso Campanella, a cura di D. M. Fazio, Congedo, Galatina 2000
No full textSi tratta della recensione della riedizione, a cura di Domenico M. Fazio, dell'importante monografia di Antonio Corsano su Tommaso Campanella, Bari, Laterza, 1961
I poteri di intervento dell’Esma
No full textCon la sentenza Regno Unito di Gran Bretagna e Irlanda del Nord, la Corte di giustizia fa salvi i poteri di emergenza attribuiti all’Esma (Autorità europea degli strumenti finanziari e dei mercati) dal regolamento (Ue) n. 236/2012 in materia di vendite allo scoperto di credit default swap (Cds). Una pronuncia importante, perché rafforza la legittimazione delle autorità europee di vigilanza finanziaria. Nelle sue argomentazioni, la Corte mostra di volersi muovere in un’ottica di continuità rispetto ai criteri da essa stessa sanciti in precedenza in materia di delega di poteri all’interno dell’Ue, in particolare con la c.d. dottrina Meroni. Accanto a tale iter logico - non privo di alcuni profili critici - si fa però strada l’elaborazione di nuovi principi che tengono conto del particolare scenario politico-economico nell’ambito del quale le nuove autorità di vigilanza finanziaria sono state istituite e che ne costituiscono la più salda base di legittimazione
PFM characterization of piezoelectric PVDF/ZnONanorod thin films
No full textThe present work reports the development and the piezoelectric characterization of nano-engineered thin-films of Polyvinylidene Fluoride (PVDF) and vertical array of zinc oxide nanorods (ZnO-NRs). In particular, the piezoelectric response of the produced samples was investigated by evaluating the piezoelectric coefficient (d33), through Piezoresponse Force Microscopy (PFM). We compared the piezoelectric response of three different samples: a neat PVDF thin-film, an array of vertically oriented ZnO-NRs and an array of vertically oriented ZnO-NRs embedded in PVDF. We tested two types of substrates: a flexible substrate namely PET-ITO and a rigid substrate namely ITO coated glass. The highest piezoelectric response was found to be exerted by the hybrid system made of vertically aligned ZnO-NRs array embedded in PVDF on PET-ITO substrate, showing a piezoelectric coefficient, as high as 14.91 pm/V
Anatomo-fisiologia della postura - metodiche strumentali per lo studio della postura in condizioni statiche
No full textA COSSERAT BASED MULTI-SCALE MODEL FOR MASONRY STRUCTURES
No full textThis paper presents a multi-scale model for the analysis of the in-plane structural response of regular masonry. It is based on a computational periodic homogenization technique and is characterized by the adoption of the Cosserat continuum model at the macroscopic structural level, taking into account the influence of the microstructure on the global response and correctly describing the localization phenomena; at the microscopic representative volume element (RVE) level, where the nonlinear constitutive behavior, geometry, and arrangement of the masonry constituents are modeled in detail, a standard Cauchy model is employed. An isotropic nonsymmetric damage model is adopted for the bricks and mortar joints. The solution algorithm is based on a parallelization strategy and on the finite-element method. Some numerical applications on typical masonry structures are reported, showing both the global response curves and the stress and damage distributions on the RVEs
A micromechanical approach for the micropolar modeling of heterogeneous periodic media
No full textComputational homogenization is adopted to assess the homogenized two-dimensional response of
periodic composite materials where the typical microstructural dimension is not negligible with respect to the
structural sizes. A micropolar homogenization is, therefore, considered coupling a Cosserat medium at the
macro-level with a Cauchy medium at the micro-level, where a repetitive Unit Cell (UC) is selected.
A third order polynomial map is used to apply deformation modes on the repetitive UC consistent with the
macro-level strain components. Hence, the perturbation displacement field arising in the heterogeneous
medium is characterized. Thus, a newly defined micromechanical approach, based on the decomposition of the
perturbation fields in terms of functions which depend on the macroscopic strain components, is adopted.
Then, to estimate the effective micropolar constitutive response, the well known identification procedure based
on the Hill-Mandel macro-homogeneity condition is exploited.
Numerical examples for a specific composite with cubic symmetry are shown. The influence of the selection of
the UC is analyzed and some critical issues are outlined
A micromechanical approach for the Cosserat modeling of composites
No full textThe present paper deals with the homogenization problem of periodic composite materials, considering a Cosserat continuum at the macro-level and a Cauchy continuum at the micro-level. Consistently with the strain-driven approach, the two levels are linked by a kinematic map based on a third order polynomial expansion. Because of the assumed regular texture of the composite material, a Unit Cell (UC) is selected; then, the problem of determining the displacement perturbation fields, arising when second or third order polynomial boundary conditions are imposed on the UC, is investigated. A new micromechanical approach, based on the decomposition of the perturbation fields in terms of functions which depend on the macroscopic strain components, is proposed. The identification of the linear elastic 2D Cosserat constitutive parameters is performed, by using the Hill–Mandel technique, based on the macrohomogeneity condition. The influence of the selection of the UC is analyzed and some critical issues are outlined. Numerical examples for a specific composite with cubic symmetry are show
Design of tunable acoustic metamaterials with periodic piezoelectric microstructure
No full textAn innovative special class of tunable periodic metamaterials is designed, suitable for realizing high-performance acoustic filters. The metamaterial is made up of a phononic crystal coupled to local resonators. Such local resonators consist of masses enclosed into piezoelectric rings, shunted by either dissipative or non-dissipative electrical circuit. By tuning the impedance/admittance of such electrical circuits, it is possible to fully adjust the constitutive properties of the shunting piezoelectric material. This feature paves the way for unconventional behaviours, well beyond the capabilities achievable with classical materials. It follows that the acoustic properties of the periodic metamaterial can be adaptively modified, in turn, opening new possibilities for the control of pass and stop bands. By exploiting a generalization of the Floquet-Bloch theory, the in-plane free wave propagation in the tunable metamaterial is investigated, by varying a certain tuning parameter, to show the efficiency of the proposed shunting piezoelectric system as a wave propagation control device. Particular attention is devoted to the determination of the in-plane constitutive equations of the shunting piezoelectric phase in the transformed Laplace space. Finally, broad design directions of tunable acoustic filters aiming to a changing performance requirement in real-time, is also provided. (C) 2020 Elsevier Ltd. All rights reserved
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