Search results for "strophe"
showing 10 items of 62 documents
On universality of critical behavior in the focusing nonlinear Schrödinger equation, elliptic umbilic catastrophe and the Tritronquée solution to the…
2008
We argue that the critical behavior near the point of “gradient catastrophe” of the solution to the Cauchy problem for the focusing nonlinear Schrodinger equation \(i\epsilon \varPsi _{t}+\frac{\epsilon^{2}}{2}\varPsi _{xx}+|\varPsi |^{2}\varPsi =0\) , e ≪1, with analytic initial data of the form \(\varPsi (x,0;\epsilon)=A(x)e^{\frac{i}{\epsilon}S(x)}\) is approximately described by a particular solution to the Painleve-I equation.
Transformation des milieux naturels et conscience environnementale à la fin du Moyen Âge : une esthétique du paysage manquante ?
2010
À partir du XIVe siècle, des exemples de plus en plus nombreux montrent que la société médiévale percevait les transformations environnementales opérées par l’action anthropique. Une réflexion, tendant à octroyer à l’aménagement humain du milieu naturel une part des responsabilités en cas de catastrophes, apparaît ainsi régulièrement dans un discours qui opposait la plupart du temps l’aspect négatif et dangereux de cette transformation du paysage à la nostalgie d’une nature « ancienne », marquée par la stabilité. Un souci environnemental important de préservation du milieu naturel, faisant plonger très loin les racines du discours écologique contemporain, se manifeste ainsi très tôt. Faisan…
Bader's analysis of the electron density in the Pbca enstatite - Pbcn protoenstatite phase transition
2011
The Bader’s topological analysis of the electron density obtained via ab initio quantum mechanical simulation at Hartree–Fock and DFT level has been performed for experimentally in situ heated structures of enstatite–protoenstatite MgSiO 3 . The measurements have been performed in the temperature range 1200–1400 K. The work was aimed at characterizing both the evolution of the electron arrangement in the crystal and that of the crystal-structure at the enstatite–protoenstatite phase transition in terms of topology of the electron density, with particular care about the Mg–O and the O–O bonds. The observed breaking of some chemical bonds with increasing temperature and/or due to the phase tr…
Truncated thermalization of incoherent optical waves through supercontinuum generation in photonic crystal fibers
2013
We revisit the process of optical wave thermalization through supercontinuum generation in photonic crystal fibers. We report theoretically and numerically a phenomenon of `truncated thermalization': The incoherent optical wave exhibits an irreversible evolution toward a Rayleigh-Jeans thermodynamic equilibrium state characterized by a compactly supported spectral shape. The theory then reveals the existence of a frequency cut-off which regularizes the ultraviolet catastrophe inherent to ensembles of classical nonlinear waves. This phenomenon sheds new light on the mechanisms underlying the formation of bounded supercontinuum spectra in photonic crystal fibers.
Condensation and thermalization of classsical optical waves in a waveguide
2011
http://pra.aps.org/; International audience; We consider the long-term evolution of a random nonlinear wave that propagates in a multimode optical waveguide. The optical wave exhibits a thermalization process characterized by an irreversible evolution toward an equilibrium state. The tails of the equilibrium distribution satisfy the property of energy equipartition among the modes of the waveguide. As a consequence of this thermalization, the optical field undergoes a process of classical wave condensation, which is characterized by a macroscopic occupation of the fundamental mode of the waveguide. Considering the nonlinear Schrödinger equation with a confining potential, we formulate a wav…
DNA Damage Response and the Balance Between Cell Survival and Cell Death
2009
DNA damage induces the activation of a cascade of kinases that trigger the DNA damage response (DDR). Downstream are targets that either help cells to survive or undergo cell death. DNA damage-induced cell death is executed by apoptosis, necrosis, mitotic catastrophe, and autophagy. Of these different forms of cell inactivation, apoptosis is often the main route of cell death following DNA damage. Cells undergo apoptosis upon genotoxic stress via the death receptor and/or the intrinsic mitochondrial damage pathway, with p53 and AP-1 involved decisively. Not every type of DNA damage induces apoptosis. Many DNA lesions are tolerated by the cell, some are mutagenic without being toxic and some…
L'alluvione di Palermo del 1557 tra rischio idrogeologico, speculazione edilizia e piani di ricostruzione
2014
Il saggio indaga, attraverso nuove significative fonti documentarie, cause e dinamiche di uno dei più drammatici eventi catastrofici che abbiano colpito la capitale del Regno di Sicilia, l'alluvione di Palermo del 1557, adesso ricondotta a scelte ingegneristiche errate e a interventi di prevenzione malfatti. Il contributo analizza, poi, gli importanti interventi di rinnovamento urbano che vennero intrapresi nell'ambito del piano di ricostruzione portato avanti congiuntamente dall'autorità viceregia e municipale.
Structural and Dynamical Complexities of Risk and Catastrophe Systems: an Approach by System Dynamics Modelling
2009
Risk and catastrophe are complex systems. Within the scope of this paper, we focus our attention on structural and dynamic complexities of catastrophes and on the possibility of modelling and simulating its double complexity with a formal and methodological framework: the General Systems Theory and System Dynamics modelling. Then we briefly propose a model of urban catastrophe related to a flood. After we propose some ways of research allowing exceeding the limits related to the modelling.
Les comportements de protection face au risque naturel : de la résistance à l’engagement
2011
An adequate risk management requires taking into account all the categories of stakeholders, including the exposed populations. Nowadays, one difficulty is to involve these populations and consequently to understand their reactions face to the eventuality of a disaster's occurrence. Several issues must be addressed: how is the representation of risk built up ? How do people develop adaptive strategies towards risk ? And above all, how is it possible to ensure an increase in behaviours suited for prevention and protection ? After drawing up a report on the research in this area, we will discuss the limitations of a persuasive communication, in order to better understand the interest of a bin…
Wege der Germanistik in transkultureller Perspektive. Akten des XIV. Kongresses der Internationalen Vereinigung für Germanistik (IVG) (Bd. 2)
2022
Exil, Migration, Vertreibung, Flucht sowie Katastrophen finden in der deutschsprachigen Literatur ein Echo. Die nach solchen Erlebnissen entstandenen psychischen Störungen und Traumata werden in diesem Band durch einen Fokus auf ein vielfältiges literarisches Korpus und auf eine breite Reihe von Autoren analysiert. Der Band enthält Beiträge zu folgenden Themen: - Katastrophenliteratur; - „Auf Leben und Tod" - zeitgenössische literarische Texte als Kommemorationsmedien des Todes im Hinblick auf transkulturelle Perspektiven einer interdisziplinären und komparatistisch orientierten thanatologischen Kulturwissenschaft; - Exil, Migration, Flucht und Vertreibung, Alte und Neue Kriege – Literarisc…