Josephson Coupling in the Dissipative State of a Thermally Hysteretic μ\mu-SQUID

Micron-sized superconducting interference devices ($\mu$-SQUIDs) based on constrictions optimized for minimizing thermal runaway are shown to exhibit voltage oscillations with applied magnetic flux despite their hysteretic behavior. We explain this remarkable feature by a significant supercurrent contribution surviving deep into the resistive state, due to efficient heat evacuation. A resistively shunted junction model, complemented by a thermal balance determining the amplitude of the critical current, describes well all experimental observations, including the flux modulation of the (dynamic) retrapping current and voltage by introducing a single dimensionless parameter. Thus hysteretic $\mu$-SQUIDs can be operated in the voltage read-out mode with a faster response. The quantitative modeling of this regime incorporating both heating and phase dynamics paves the way for further optimization of $\mu$-SQUIDs for nano-magnetism.Comment: 10 pages, 11 figures, Revise

Estimating the technical efficiency of damage abatment inputs: an application to pesticides in France

Estimating the technical efficiency of damage abatment inputs: an application to pesticides in Franc

La croissance tendancielle des dépenses de santé : un problème sensible pour les finances publiques des pays développés.

De nombreux pays, dont la France, ont entrepris des réformes davantage orientées vers des solutions microéconomiques pour faire face à la hausse tendancielle des dépenses de santé.

Dynamic instabilities of fracture under biaxial strain using a phase field model

We present a phase field model of the propagation of fracture under plane strain. This model, based on simple physical considerations, is able to accurately reproduce the different behavior of cracks (the principle of local symmetry, the Griffith and Irwin criteria, and mode-I branching). In addition, we test our model against recent experimental findings showing the presence of oscillating cracks under bi-axial load. Our model again reproduces well observed supercritical Hopf bifurcation, and is therefore the first simulation which does so

Phase-field simulations of viscous fingering in shear-thinning fluids

A phase-field model for the Hele-Shaw flow of non-Newtonian fluids is developed. It extends a previous model for Newtonian fluids to a wide range of shear-dependent fluids. The model is applied to perform simulations of viscous fingering in shear- thinning fluids, and it is found to be capable of describing the complete crossover from the Newtonian regime at low shear rate to the strongly shear-thinning regime at high shear rate. The width selection of a single steady-state finger is studied in detail for a 2-plateaux shear-thinning law (Carreau law) in both its weakly and strongly shear-thinning limits, and the results are related to previous analyses. In the strongly shear-thinning regime a rescaling is found for power-law (Ostwald-de-Waehle) fluids that allows for a direct comparison between simulations and experiments without any adjustable parameters, and good agreement is obtained

Dispersion monitoring for high-speed WDM networks via two-photon absorption in a semiconductor microcavity

Due to the continued demand for bandwidth, network operators have to increase the data rates at which individual wavelengths operate at. As these data rates will exceed 100 Gbit/s in the next 5-10 years, it will be crucial to be able to monitor and compensate for the amount of chromatic dispersion encountered by individual wavelength channels. This paper will focus on the use of the novel nonlinear optical-to-electrical conversion process of two-photon absorption (TPA) for dispersion monitoring. By incorporating a specially designed semiconductor microcavity, the TPA response becomes wavelength dependent, thus allowing simultaneous channel selection and monitoring without the need for external wavelength filterin

Sensitivity of double resonance alignment magnetometers

We present an experimental study of the intrinsic magnetometric sensitivity of an optical/rf-frequency double resonance magnetometer in which linearly polarized laser light is used in the optical pumping and detection processes. We show that a semi-empirical model of the magnetometer can be used to describe the magnetic resonance spectra. Then, we present an efficient method to predict the optimum operating point of the magnetometer, i.e., the light power and rf Rabi frequency providing maximum magnetometric sensitivity. Finally, we apply the method to investigate the evolution of the optimum operating point with temperature. The method is very efficient to determine relaxation rates and thus allowed us to determine the three collisional disalignment cross sections for the components of the alignment tensor. Both first and second harmonic signals from the magnetometer are considered and compared

Appearance of Gauge Fields and Forces beyond the adiabatic approximation

We investigate the origin of quantum geometric phases, gauge fields and forces beyond the adiabatic regime. In particular, we extend the notions of geometric magnetic and electric forces discovered in studies of the Born-Oppenheimer approximation to arbitrary quantum systems described by matrix valued quantum Hamiltonians. The results are illustrated by several physical relevant examples

Spatialisation des Transaction Foncière Agricoles dans la Commune d’Abomey-Calavi

RésumeLa maîtrise du foncier constitue l’un des atouts essentiels de toute politique de développement digne de ce nom. Cependant, force est de constater que la gestion de terre dans la Commune d’Abomey-Calavi  souffre d’un mal rédhibitoire qui en fait un véritable instrument de désastre économique. Le présent travail est de spatialiser les différentes modes d’accès à la terre dans la Commune d’Abomey-calavi.La démarche méthodologique adoptée  porte sur la spatialisation des données cartographique issues de l’IGN sur chaque arrondissement de la commune d’          Abomey-calavi, les enquêtes de  terrain, le traitement des données et l’analyse des résultats. Les données et informations recueillies sont traitées et analysées puis complétées par les investigations en milieu réel.Les résultats montrent que l’héritage représente le mode d’accès le plus pratiqué dans la commune d’Abomey-calavi suivi de l’achat. L’héritage non-partagé représente 8 % des superficies cultivées dans la commune. Il prend en compte 18% des terres agricoles à Glo-djigbé, Akassato, Zinvié, ouèdo et Togba. Il représente  10 % à Abomey-Calavi, Hèvé, Kpanroun et Godomey.  Le don s’opère entre époux ou entre beau-père et gendre. Une analyse des taux des différents modes d’accès à la terre permet de constater que dans la commune d’Abomey-calavi le don est le mode d’accès à la terre qui est moins développé. Mots Clés : Spatialisation, Transaction foncière, Agricoles, Commune d’Abomey-calaviAbstractControl of land is one of the essential assets of any development policy worthy of the name. However, it is clear that land management in the Municipality of Abomey-Calavi suffers from a crippling evil that makes it a real instrument of economic disaster. The present work is to spatialize the different modes of access to land in the Municipality of Abomey-calavi.The methodological approach adopted concerns the spatialization of cartographic data from the IGN on each district of the municipality of Abomey-calavi, field surveys, data processing and analysis of the results. The data and information collected are processed and analyzed and then supplemented by investigations in the real environment.The results show that inheritance represents the most practiced mode of access in the municipality of Abomey-calavi followed by purchase. Non-shared inheritance represents 8% of cultivated areas in the municipality. It takes into account 18% of agricultural land in Glo-djigbé, Akassato, Zinvié, ouèdo and Togba. It represents 10% in Abomey-Calavi, Hèvé, Kpanroun and Godomey. The donation takes place between spouses or between father-in-law and son-in-law. An analysis of the rates of the different modes of access to land shows that in the municipality of Abomey-calavi, donation is the mode of access to land that is less developed.Keywords: Spatialization, Land transaction, Agricultural, Municipality of Abomey-calav

Euler hydrodynamics for attractive particle systems in random environment

We prove quenched hydrodynamic limit under hyperbolic time scaling for bounded attractive particle systems on $\Z$ in random ergodic environment. Our result is a strong law of large numbers, that we illustrate with various examples.Comment: 36 page