Search results for "LIMIT"
showing 10 items of 2826 documents
The limit state of indefinite plates on elastoplastic continuum
1972
The limit analysis of indefinite plates resting on a continuous elastoplastic medium and subjected to a load distributed over a partial surface with a circular boundary yields the fundamental equation governing the problem. Minimum conditions are set and the solution that supplies the collapse load of the plate-soil system is found by variational calculus.
Deviations from equilibrium at the interface of a charged membrane
1989
The local equilibrium assumption commonly employed for the transport through the interface of a charged membrane has been analysed from a simplified electric double layer model. This layer is characterized on the basis of a surface potential arising from a non-zero surface charge density placed on the membrane surface. The dependence of deviations from local equilibrium on the characteristic parameters of the problem is shown. Connection with the classical treatment by Donnan is discussed. Although the complexity of the problem calls for a number of simplifications, the results obtained appears to be significative. Thus, the analysis carried out displays not only that deviations from equili…
Mechanical desorption of a single chain: unusual aspects of phase coexistence at a first-order transition.
2012
The phase transition occurring when a single polymer chain adsorbed at a planar solid surface is mechanically desorbed is analyzed in two statistical ensembles. In the force ensemble, a constant force applied to the nongrafted end of the chain (that is grafted at its other end) is used as a given external control variable. In the $z$-ensemble, the displacement $z$ of this nongrafted end from the surface is taken as the externally controlled variable. Basic thermodynamic parameters, such as the adsorption energy, exhibit a very different behavior as a function of these control parameters. In the thermodynamic limit of infinite chain length the desorption transition with the force as a contro…
Limit Periodic Sets
1998
As explained at the end of the previous chapter, the most difficult problem in the study of bifurcations in a family of vector fields on a surface of genus 0 is the control of the periodic orbits. In fact, in generic smooth families the periodic orbits will be isolated for each value of the parameter. For analytic families we have two possibilities for each orbit: it may be isolated or belong to a whole annulus of periodic orbits. In this last case and for the parameter values for which the system has infinitely many periodic orbits, the vector field has a local analytic first integral and the nearby vector fields in the family may be studied by the perturbation theory introduced in Chapter…
Bridging scales with thermodynamics: from nano to macro
2014
We have recently developed a method to calculate thermodynamic properties of macroscopic systems by extrapolating properties of systems of molecular dimensions. Appropriate scaling laws for small systems were derived using the method for small systems thermodynamics of Hill, considering surface and nook energies in small systems of varying sizes. Given certain conditions, Hill's method provides the same systematic basis for small systems as conventional thermodynamics does for large systems. We show how the method can be used to compute thermodynamic data for the macroscopic limit from knowledge of fluctuations in the small system. The rapid and precise method offers an alternative to curre…
Kirkwood–Buff Integrals Using Molecular Simulation: Estimation of Surface Effects
2020
Kirkwood&ndash
Surface homeomorphisms with zero dimensional singular set
1998
We prove that if f is an orientation-preserving homeomorphism of a closed orientable surface M whose singular set is totally disconnected, then f is topologically conjugate to a conformal transformation.
Tree Singularities: Limits, Series and Stability
2013
A tree singularity is a surface singularity that consists of smooth components, glued along smooth curves in the pattern of a tree. Such singularities naturally occur as degenerations of certain rational surface singularities. To be more precise, they can be considered as limits of certain series of rational surface singularities with reduced fundamental cycle. We introduce a general class of limits, construct series deformations for them and prove a stability theorem stating that under the condition of finite dimensionality of T 2 the base space of a semi-universal deformation for members high in the series coincides up to smooth factor with the “base space of the limit”. The simplest tree…
Calcul direct d'une tesselation de la surface limite pour les schémas de subdivision uniformes
2017
International audience; Le peu d'utilisation des surfaces de subdivision dans les systèmes CAO est principalement lié au fait que la surface est le plus souvent seulement approchée par des niveaux de raffinement successifs, ce qui induit un manque de pré-cision. De plus, il est difficile d'intégrer la représentation des surfaces de subdivision dans le noyau géométrique (ensemble de primitives et d'outils) des applications CAO. C'est dans ce but que nous décrirons un formalisme général de construction de surfaces de subdivision basé sur les Systèmes Itérés de Fonctions. Le principal apport est que toutes les surfaces de subdivision classiques sont gérées de la même manière quel que soit le s…
Limits of Surgical Resection for Bile Duct Cancer
2015
<b><i>Introduction:</i></b> Perihilar cholangiocarcinoma is the most frequent cholangiocarcinoma and poses difficulties in preoperative evaluation. For its therapy, often major hepatic resections as well as resection and reconstruction of the hepatic artery or the portal vein are necessary. In the last decades, great advances were made in both the surgical procedures and the perioperative anesthetic management. In this article, we describe from our point of view which facts represent the limits for curative (R0) resection in perihilar cholangiocarcinoma. <b><i>Methods:</i></b> Retrospective data of a 6-year period (2008-2014) was collected in …