4,615 research outputs found
PIL and CISG: Friends of Foes?
No full textIl contributo analizza il rapporto tra il diritto materiale uniforme, e in particolare la Convenzione di Vienna, e il diritto internazionale privat
A direct A.C. to A.C. regenerative frequency and voltage converter
No full textIncludes bibliographical references.The reliable variable speed operation of an a. c. machine over a wide speed range is a problem that has received attention for some time. In this thesis a system to permit such operation from a fixed frequency fixed voltage supply is proposed, under the name of the asynchronous modulation converter. This converter is of the cycloconverter family, but is force-commutated and is not synchronised with the supply frequency. The power switching element comprises a power transistor in a diode bridge, coupled to the control circuitry by opto-isolators. The output of the a-mod converter is produced by a "chopper" modulation process and this results in the harmonics present being at frequencies well removed from the fundamental. A feedback system to ensure smooth commutation of the output current from the power switches is described. This feedback system operates by sensing the rate of rise of the inductive voltage surge on the load when a switch is opened to operate a freewheel path switch
Eddy stirring in the Southern Ocean
No full textThere is an ongoing debate concerning the distribution of eddy stirring across the Antarctic Circumpolar Current (ACC) and the nature of its controlling processes. The problem is addressed here by estimating the isentropic eddy diffusivity ? from a collection of hydrographic and altimetric observations, analyzed in a mixing length theoretical framework. It is shown that, typically, ? is suppressed by an order of magnitude in the upper kilometer of the ACC frontal jets relative to their surroundings, primarily as a result of a local reduction of the mixing length. This observation is reproduced by a quasi-geostrophic theory of eddy stirring across a broad barotropic jet based on the scaling law derived by Ferrari and Nikurashin (2010). The theory interprets the observed widespread suppression of the mixing length and ? in the upper layers of frontal jets as the kinematic consequence of eddy propagation relative to the mean flow within jet cores. Deviations from the prevalent regime of mixing suppression in the core of upper-ocean jets are encountered in a few special sites. Such ‘leaky jet’ segments appear to be associated with sharp stationary meanders of the mean flow that are generated by the interaction of the ACC with major topographic features. It is contended that the characteristic thermohaline structure of the Southern Ocean, consisting of multiple upper-ocean thermohaline fronts separated and underlaid by regions of homogenized properties, is largely a result of the widespread suppression of eddy stirring by parallel jets
NUEVAS COMBINACIONES EN MONOCOTILEDÓNEAS MEXICANAS IV (BROMELIACEAE, ORCHIDACEAE)
No full textSe propone elevar a Tillandsia tortilis Klotzsch ex Baker ssp. curvifolia Ehlers et Rauh al nivel específico con el nombre de Viridantha curvifolia (Ehlers et Rauh) López- Ferrari et Espejo. Asimismo se presenta a Malaxis zempoalensis López-Ferrari et Espejo como nuevo nombre para Malaxis palustris Espejo et López-Ferrari
Dos nuevas especies de Commelina (Commelinaceae) mexicanas
No full textEn este trabajo se describen e ilustran Commelina nivea López-Ferrari, Espejo et Ceja y Commelina rzedowskii López-Ferrari, Espejo et Ceja, dos nuevas especies de flores blancas. La primera es conocida únicamente de Las Adjuntas, municipio de Pueblo Nuevo en Durango, en tanto
que la segunda proviene de las vecindades de Tenería, municipio de Tejupilco en el estado de México
Tres nuevas especies de Commelina (Commelinaceae) del centro de M\ue9xico
No full textEn este trabajo se describen como nuevas e ilustran Commelina congestispatha
López-Ferrari, Espejo et Ceja, Commelina ramosissima López-Ferrari, Espejo et Ceja y
Commelina queretarensis López-Ferrari, Espejo et Ceja. La primera es conocida de los
estados de Michoacán, Guanajuato y Querétaro, la segunda proviene de los estados de
Guanajuato, Querétaro y Michoacán y la tercera se conoce sólo del estado de Querétaro, de
los municipios de San Joaquín y Landa de Matamoros
Il Dialogo dell'Oratore di Cicerone
No full textMarca tip. en port., v. de h. 176 y v. de 2*\b8\sSign.: *\p8\s, A-Y\p8\s, 2*\p8\
Curci-Ferrari mass and the Neuberger problem
No full textCopyright © 2005. Physics Letters. All rights reserved. Printed in U.S.A. Submitted to Cornell University’s online archive www.arXiv.org in 2005 by Alexander Kalloniatis. Post-print sourced from www.arxiv.org.We study the massive Curci–Ferrari model as a starting point for defining BRST quantisation for Yang–Mills theory on the lattice. In particular, we elucidate this proposal in light of topological approaches to gauge-fixing and study the case of a simple one-link Abelian model.http://www.elsevier.com/wps/find/journaldescription.cws_home/505706/description#descriptio
Notas nomenclaturales sobre Iridaceae
No full textSe aclara la situación nomenclatural de T. vanhouttei (Baker) Espejo & López-Ferrari, T. augusta Drapiez y T. violacea Schiede ex Schltdl. y se proponen nuevas combinaciones en
Sisyrinchium
I materiali di età celtica dalla struttura 2 di Casalecchio di Reno (Bo), zona “A”
No full textSono presentati i materiali archeologici di età celtica rinvenuti in un'area limitrofa all'abitato etrusco di Casalecchio di Reno, zona A. I reperti, rappresentati principalmente da vasellame di ceramica e oggetti metallici, sono ascrivibili ad un arco cronologico compreso tra la seconda metà del IV e il terzo quarto del III sec. a.C. Tali ritrovamenti indicano la presenza di un abitato celtico nelle vicinanze, forse corrispondente ad una frequentazione tarda delle strutture abitative etrusche poste nelle vicinanze
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