Search results for "strophe"
showing 10 items of 62 documents
Electronic fluxes during diels-alder reactions involving 1,2-benzoquinones: mechanistic insights from the analysis of electron localization function …
2012
By means of the joint use of electron localization function (ELF) and Thom's catastrophe theory, a theoretical analysis of the energy profile for the hetero-Diels-Alder reaction of 4-methoxy-1,2-benzoquinone 1 and methoxyethylene 2 has been carried out. The 12 different structural stability domains obtained by the bonding evolution theory have been identified as well as the bifurcation catastrophes (fold and cusp) responsible for the changes in the topology of the system. This analysis permits finding a relationship between the ELF topology and the evolution of the bond breaking/forming processes and electron pair rearrangements through the reaction progress in terms of the different ways o…
Health sector spending and spending on HIV/AIDS, tuberculosis, and malaria, and development assistance for health: progress towards Sustainable Devel…
2020
BACKGROUND: Sustainable Development Goal (SDG) 3 aims to "ensure healthy lives and promote well-being for all at all ages". While a substantial effort has been made to quantify progress towards SDG3, less research has focused on tracking spending towards this goal. We used spending estimates to measure progress in financing the priority areas of SDG3, examine the association between outcomes and financing, and identify where resource gains are most needed to achieve the SDG3 indicators for which data are available. METHODS: We estimated domestic health spending, disaggregated by source (government, out-of-pocket, and prepaid private) from 1995 to 2017 for 195 countries and territories. For …
Nature of the ring-closure process along the rearrangement of octa-1,3,5,7-tetraene to cycloocta-1,3,5-triene from the perspective of the electron lo…
2011
We analyze the behavior of the energy profile of the ring-closure process for the transformation of (3Z,5Z)-octa-1,3,5,7-tetraene 5 to (1Z,3Z,5Z)-cycloocta-1,3,5-triene 6 through a combination of electron localization function (ELF) and catastrophe theory (CT). From this analysis, concepts such as bond breaking/forming processes, formation/annihilation of lone pairs, and other electron pair rearrangements arise naturally through the reaction progress simply in terms of the different ways of pairing up the electrons. A relationship between the topology and the nature of the bond breaking/forming processes along this rearrangement is reported. The different domains of structural stability of …
Risque urbain, catastrophes et villes méditerranéennes
2007
International audience
A proposition of classification of the catastrophe systems based on complexity criteria
2007
Cet article est diffusé sur internet et ne figure pas dans un ouvrage : voir à l'adresse suivante http://www-lih.univ-lehavre.fr/~bertelle/epnacs2007-proceedings/provitolo4epnacs07.pdf; International audience; A classification system of catastrophic events is a methodologyassembling all the catastrophes groups. It is possible to identify several catastrophesclassifications. The most widely known are classified into: nature, consequencesof the event, duration, affected territories and areas of the destroyedzone, and at last into the needed intervention measures. But these criteria ofclassification allow with difficulty to apprehend the complexity of the catastrophe.Thus we propose a classifi…
On critical behaviour in systems of Hamiltonian partial differential equations
2013
Abstract We study the critical behaviour of solutions to weakly dispersive Hamiltonian systems considered as perturbations of elliptic and hyperbolic systems of hydrodynamic type with two components. We argue that near the critical point of gradient catastrophe of the dispersionless system, the solutions to a suitable initial value problem for the perturbed equations are approximately described by particular solutions to the Painlevé-I (P $$_I$$ I ) equation or its fourth-order analogue P $$_I^2$$ I 2 . As concrete examples, we discuss nonlinear Schrödinger equations in the semiclassical limit. A numerical study of these cases provides strong evidence in support of the conjecture.
Electron-density critical points analysis and catastrophe theory to forecast structure instability in periodic solids
2018
The critical points analysis of electron density,i.e. ρ(x), fromab initiocalculations is used in combination with the catastrophe theory to show a correlation between ρ(x) topology and the appearance of instability that may lead to transformations of crystal structures, as a function of pressure/temperature. In particular, this study focuses on the evolution of coalescing non-degenerate critical points,i.e. such that ∇ρ(xc) = 0 and λ1, λ2, λ3≠ 0 [λ being the eigenvalues of the Hessian of ρ(x) atxc], towards degenerate critical points,i.e. ∇ρ(xc) = 0 and at least one λ equal to zero. The catastrophe theory formalism provides a mathematical tool to model ρ(x) in the neighbourhood ofxcand allo…
"Far-off gleams of evangelium" : a study of how J. R. R. Tolkien's The lord of the rings reflects the biblical "Kingdom of Heaven"
2008
Knowledge-driven multi-agent simulation engineering for assessing the effectiveness of disaster management plans
2020
Protecting humans from disasters has been an active mission of governments and experts through the definition of disaster management plans. Defining disaster response strategies is crucial in order to reduce the number of victims and the economic impact. In order to select which response plan is best suited to a specific disaster situation, these plans must be evaluated. However, such evaluation is limited by the high cost of exercises and the specificity of existing simulation models. The approach defended in this thesis combines techniques from Semantic Web and multi-agent simulation to evaluate disaster management response plans. It is composed of four steps : (1) modeling disaster manag…
Wicked behavior and catastrophes in the Roman world: believes, religiosity and politic
2014
La religión es un componente tan esencial en las sociedades del Mundo Antiguo que de su correcta difusión y de la perfecta realización de los cultos depende la disposición de los dioses y, con ella, el devenir de los acontecimientos. En la vida práctica, esto se transmite en dos ámbitos: la élite, el grupo encargado de la celebración de los ritos no puede cometer errores en su tarea; y el pueblo, todos los habitantes del territorio tienen que adherirse a la religión “estatal”. Cuando en alguno de estos dos elementos se producen fallos, se suceden prodigios y catástrofes de cualquier tipo. Frente a esto, la solución consiste en: castigo del causante o causantes de la impiedad y reparación de…