THEORETICAL CONSIDERATIONS FOR A PRELIMINARY DESIGN OF A SOLAR CELL GENERATOR ON A SATELLITE

Solar cell generators for satellite power supply - design theor

Enhancement of mobilities in a pinned multidomain crystal

Mobility properties inside and around degenerate domains of an elastic lattice partially pinned on a square array of traps are explored by means of a fully controllable model system of macroscopic particles. We focus on the different configurations obtained for filling ratios equal to 1 or 2 when the pinning strength is lowered. These theoretically expected but never observed configurations are degenerated, which implies the existence of a multidomain crystal. We show that the distinction between trapped and untrapped particles that is made in the case of strong pinning is not relevant for such a weaker pinning. Indeed, one ought to distinguish between particles inside or around the domains associated to positional degeneracies. The possible consequences on the depinning dynamics of the lattice are discussed.Comment: 7 pages, 10 figures Version 2 : longer versio

The effect of undrained heating on a fluid-saturated hardened cement paste

The effect of undrained heating on volume change and induced pore pressure increase is an important point to properly understand the behaviour and evaluate the integrity of an oil well cement sheath submitted to rapid temperature changes. This thermal pressurization of the pore fluid is due to the discrepancy between the thermal expansion coefficients of the pore fluid and of the solid matrix. The equations governing the undrained thermo-hydro-mechanical response of a porous material are presented and the effect of undrained heating is studied experimentally for a saturated hardened cement paste. The measured value of the thermal pressurization coefficient is equal to 0.6MPa/°C. The drained and undrained thermal expansion coefficients of the hardened cement paste are also measured in the heating tests. The anomalous thermal behaviour of cement pore fluid is back analysed from the results of the undrained heating test.Comment: Cement and Concrete Research (2008) In pres

Polluting emissions standards and clean technology trajectories under competitive selection and supply chain pressure

Based on a model of industrial dynamics, this paper examines the impact of polluting emissions standards on trajectories of clean technologies implemented by firms subject to competitive selection and supply chain pressure. The model incorporates a few stylised facts on the relationships between environmental regulation, innovation and diffusion. The main objective is to highlight the forces influencing the long term dynamics of an industry faced with evolving emissions standards in a ‘history-friendly’ way. The paper gives guidance to the conditions of dynamic efficiency of emissions standards taking into account the coevolution of technology, user requirements and market structure. We show that emission standards not only play a significant role in orienting research and innovation activities of supplier firms, but they are also likely to support the diffusion of environmental innovation in the supply chain. In some cases, emission standards lead to prevent both a situation of lock-in on the supply side and a situation of behavioural inertia on the user side. Standards may thus lead to preserve a certain form of technological and behavioural diversity. Based on the computer simulations, it will be shown that the efficiency of standards depends on the nature of performance standards (process or product), on the market structure and on the timing of intervention.environmental innovation; industrial dynamics; environmental supply chain pressure; emission standards

Guaranteed Inertia Functions in Dynamical Games.

This paper deals with inertia functions in control theory introduced in Aubin, Bernardo and Saint-Pierre (2004, 2005) and their adaptation to dynamical games. The inertia function associates with any initial state-control pair the smallest of the worst norms over time of the velocities of the controls regulating viable evolutions. For tychastic systems (parameterized systems where the parameters are tyches, disturbances, perturbations, etc.), the palicinesia of a tyche measure the worst norm over time of the velocities of the tyches. The palicinesia function is the largest palicinesia threshold c such that all evolutions with palicinesia smaller than or equal to c are viable. For dynamical games where one parameter is the control and the other one is a tyche (games against nature or robust control), we define the guaranteed inertia function associated with any initial state-control-tyche triple the best of the worst of the norms of the velocities of the controls and of the tyches and study their properties. Viability Characterizations and Hamilton-Jacobi equations of which these inertia and palicinesia functions are solutions are provided.Viability; dynamical games; inertia function; Tychastic systems; palicinesia;

Incrementalism of environmental innovations versus paradigmatic change: A comparative study of the automotive and chemical industries

Environmental innovations; technological regime; technological paradigm; environmental regulation; automotive industry; green chemistry

Single File Diffusion enhancement in a fluctuating modulated 1D channel

We show that the diffusion of a single file of particles moving in a fluctuating modulated 1D channel is enhanced with respect to the one in a bald pipe. This effect, induced by the fluctuations of the modulation, is favored by the incommensurability between the channel potential modulation and the moving file periodicity. This phenomenon could be of importance in order to optimize the critical current in superconductors, in particular in the case where mobile vortices move in 1D channels designed by adapted patterns of pinning sites.Comment: 4 pages, 4 figure

Les enfants de l'immigration : identité inachevée, normes à inventer

Las poblaciones imigradas rechazan su relégacion. No son revendicaciones de su comunidad que llevo a las révoltas afueras de Paris sino pedir igualdad de los derechos. En Marsella, la movilizacion por revendicacions sociales engendra un sentimiento de pertinancia y emergencia de una idendidad parlicular cuale participa a construir una identitaire inclusiva en contra le las normas excluantes y exclusivas.Les populations issues de l'immigration refusent leur relégation. Ce ne sont pas des revendications identitaires qui ont suscité la « révolte des banlieues » mais la revendication d'égalité de droit. À Marseille, la mobilisation autour de revendications sociales génère un sentiment d'appartenance et l'émergence d'une identité particulière pour construire une identité inclusive contre des normes excluantes et exclusives

Dynamic Management of Portfolios with Transaction Costs under Tychastic Uncertainty.

We use in this chapter the viability/capturability approach for studying the problem of dynamic valuation and management of a portfolio with transaction costs in the framework of tychastic control systems (or dynamical games against nature) instead of stochastic control systems. Indeed, the very definition of the guaranteed valuation set can be formulated directly in terms of guaranteed viable-capture basin of a dynamical game. Hence, we shall “compute” the guaranteed viable-capture basin and find a formula for the valuation function involving an underlying criterion, use the tangential properties of such basins for proving that the valuation function is a solution to Hamilton-Jacobi-Isaacs partial differential equations. We then derive a dynamical feedback providing an adjustment law regulating the evolution of the portfolios obeying viability constraints until it achieves the given objective in finite time. We shall show that the Pujal—Saint-Pierre viability/capturability algorithm applied to this specific case provides both the valuation function and the associated portfolios.dynamic games; dynamic valuation; tychastic control systems; management of portfolio;