A rigorous approach to the magnetic response in disordered systems

This paper is a part of an ongoing study on the diamagnetic behavior of a 3-dimensional quantum gas of non-interacting charged particles subjected to an external uniform magnetic field together with a random electric potential. We prove the existence of an almost-sure non-random thermodynamic limit for the grand-canonical pressure, magnetization and zero- field orbital magnetic susceptibility. We also give an explicit formulation of these thermodynamic limits. Our results cover a wide class of physically relevant random potentials which model not only crystalline disordered solids, but also amorphous solids.Comment: 35 pages. Revised version. Accepted for publication in RM

Data assimilation for hydraulic state estimation of a development project

International audienceAssurer la sûreté hydraulique sur les aménagements du Rhône est la priorité pour la Compagnie Nationale du Rhône. Cela signifie qu'il est indispensable de respecter les consignes d'exploitation sur les aménagements. Pour la régulation automatique des aménagements, le calcul de la commande prédictive s'appuie sur les mesures en cote en certains points caractéristiques ainsi que sur les débits aux ouvrages. De ce fait, lors de pannes de capteurs ou bien lors de forts phénomènes transitoires (tels que des arrêts ou démarrages de turbines), la régulation est perturbée. Suite à la présente étude, la solution proposée pour corriger les observations et mettre à jour les lignes d'eau intervenant dans le calcul des commandes, est la mise en place d'une méthode d'assimilation de données de type filtre de Kalman. Cette méthode est optimale dans le sens où elle assure la minimisation de l'erreur d'estimation. Mais cela n'est pas suffisant pour certaines applications industrielles. C'est pourquoi les notions de détectabilité et de convergence ont été approfondies. Cette étude a permis de déterminer des conditions suffisantes qui assurent une erreur de l'estimation convergente vers une moyenne nulle. Pour tester la mise en place d'une telle méthode, celle-ci a été implémentée sur l'outil de test industriel appelé " plateforme de simulation ". Des exemples de scénarios habituellement difficiles pour les régulations automatiques, telles que la perte de capteur et l'arrêt brutal d'une turbine sont présentés. Ils permettent de démontrer l'apport de la solution proposée. / Ensure the safety of development projects of the Rhône is the priority of the Compagnie Nationale du Rhône. That means it is essential to respect the water levels at some set points along the river. To regulate its development projects, the computation of the predictive control is based on measurements at the characteristic points as well as flows at the hydraulic facilities. Thus, when failures of sensors occur or during strong transients (such as stopping or starting the turbines), the regulation process can be disturbed. Following this study, the new solution suggested to detect sensor defaults, to correct the observations and to update the water profiles involved in the calculation of control actions, is based on a data assimilation method (Kalman Filter). This method is optimal because it ensures minimizing the estimation error. But this property is not sufficient for our industrial application. This is why the notions of detectability and convergence have been studied into detail. This study has identified sufficient conditions that ensure the error of the estimate to converge towards a nil average. In order to test and validate such a method, it has been implemented into the industrial test tool called "simulation platform." Examples of usually difficult scenarios simulating a loss of sensor and an unexpected stopping of a turbine are presented in this document. It allows demonstrating the benefits of the presented solution

A coproduct structure on the formal affine Demazure algebra

In the present paper we generalize the coproduct structure on nil Hecke rings introduced and studied by Kostant-Kumar to the context of an arbitrary algebraic oriented cohomology theory and its associated formal group law. We then construct an algebraic model of the T-equivariant oriented cohomology of the variety of complete flags.Comment: 28 pages; minor revision of the previous versio

PRELIMINARY SURVEY OF COUNTERFEITING OF ALBENDAZOLE AND METRONIDAZOLE MARKETED IN LUBUMBASHI

Objective: Counterfeit medicines represent a major health risk in the treatment of various pathologies. They are responsible for resistance emergence in the treatment of infectious diseases. This study was conducted in order to identify illegal and legal drugs marketed in the city of Lubumbashi and assess the quality of all samples concerned by this study.Methods: The study included albendazole and metronidazole for oral administration. Visual inspection of medicines, investigation of the authenticity of drugs from pharmaceutical regulatory authorities, and determination of content were used as study parameters.Results: A total of 34 samples were collected including 19 of albendazole and 15 of metronidazole. 11 (32%) samples were not permitted to be marketed. 9 (26 %) samples were substandard according to the US Pharmacopoeia in terms of the content of active ingredient: all of them, the active ingredient was found to present in a lower amount (under-dosing). The proportion of non-compliance is highest among medicines not permitted to be marketed (78% vs 8.0%; p˂0.005). Conclusion: It is obvious that strengthening the capacity of drug regulatory authority of the DR Congo can reduce the influx of counterfeit/substandard drugs in Lubumbashi.Keywords: Medicines, Counterfeiting, Antiparasitics, DR Congo, Lubumbash

Diamagnetism of quantum gases with singular potentials

We consider a gas of quasi-free quantum particles confined to a finite box, subjected to singular magnetic and electric fields. We prove in great generality that the finite volume grand-canonical pressure is jointly analytic in the chemical potential ant the intensity of the external magnetic field. We also discuss the thermodynamic limit

Vigour and behaviour of fifteen citrus varieties against tristeza in the forest zone of Cameroon

Fifteen varieties or combinations of citrus (lime, grapefruit, lemons, oranges, mandarin and hybrids) were characterized in the forest zone of Cameroon. Characterization was carried out based on the behaviour of these citrus varieties against citrus tristeza virus (CTV). Foliar and cortical symptoms were evaluated. Six years old plants did not show any immune reaction against the disease. Unusual mild symptoms were observed in varieties normally tolerant to the disease, which constitute an indicator of  the presence of a virulent viral complex. Satsuma mandarin, Lisbon lemon, Eureka lemon and in some aspects Tahiti lime showed a satisfactory behaviour for their vigour and reaction against CTV

The importance of a small ephemeral tributary for fine sediment dynamics in a main‐stem river

Studies of ephemeral streams have focused mainly in arid and semi‐arid regions. Such streams also occur widely in temperate regions, but much less is known about their influence on fluvial processes in main‐stem rivers here. In this paper, we present evidence of the importance of a small ephemeral temperate stream for main‐stem fine sediment dynamics. The paper focuses on a restoration project (River Ehen, North West England) which involved the reconnection of a headwater tributary to the main‐stem river. We present data on suspended sediment transport 2 years prior to and 2 years following the reconnection. Despite the small size and non‐perennial flow of the tributary, its reconnection resulted in an increase of 65% in the main‐stem sediment yield. During both the pre‐reconnection and post‐reconnection periods, a higher proportion of the annual yield was conveyed during short events with relatively high suspended sediment concentrations. Following the reconnection, the magnitude and frequency of such events increased, primarily due to sediment being delivered from the tributary at times when main‐stem flows were not elevated. Overall, the main‐stem remains supply limited and so is highly dependent on sediment delivered from the tributary. The study helps stress that even non‐perennial tributaries yielding only a small increase in catchment size (+1.2% in this case) can have a major influence on main‐stem fluvial dynamics. Their role as sediment sources may be especially important where, as in the case of the Ehen, the main‐stem is regulated and the system is otherwise starved of sediment.Damià Vericat is funded by a Ramon y Cajal Fellowship (RYC‐2010‐06264). Authors acknowledge the support from the Economy and Knowledge Department of the Catalan Government through the Consolidated Research Group “Fluvial Dynamics Research Group”—RIUS (2014 SGR 645), and the additional support provided by the CERCA Programme, also from the Catalan Government

Models and Strategies for Variants of the Job Shop Scheduling Problem

Recently, a variety of constraint programming and Boolean satisfiability approaches to scheduling problems have been introduced. They have in common the use of relatively simple propagation mechanisms and an adaptive way to focus on the most constrained part of the problem. In some cases, these methods compare favorably to more classical constraint programming methods relying on propagation algorithms for global unary or cumulative resource constraints and dedicated search heuristics. In particular, we described an approach that combines restarting, with a generic adaptive heuristic and solution guided branching on a simple model based on a decomposition of disjunctive constraints. In this paper, we introduce an adaptation of this technique for an important subclass of job shop scheduling problems (JSPs), where the objective function involves minimization of earliness/tardiness costs. We further show that our technique can be improved by adding domain specific information for one variant of the JSP (involving time lag constraints). In particular we introduce a dedicated greedy heuristic, and an improved model for the case where the maximal time lag is 0 (also referred to as no-wait JSPs).Comment: Principles and Practice of Constraint Programming - CP 2011, Perugia : Italy (2011

High-Level Behavior Regulation for Multi-Robot Systems

International audienceWe propose a new collaborative guidance platform for a team of robots that should protect a fixed ground target from one or several threats. The team of robots performs high-level behaviors. These are hand-coded since they consist in driving the robots to some given position. However, deciding when and how to use these behaviors is much more challenging. Scripting high-level interception strategies is a complex problem and applicable to few specific application contexts. We propose to use a gene regulatory network to regulate high-level behaviors and to enable the emergence of efficient and robust interception strategies