Stability and performance analysis of classical decentralized control of irrigation canals

Irrigation canals have a series structure which is generally used to design multivariable controllers based on the aggregation of decentralized monovariable controllers. SISO controllers are designed for each canal pool, assuming that the interactions will not destabilize the overall system. It is shown that, when the canal pools are controlled using the discharge at one boundary, the multivariable decentralized control structure is stable if and only if the SISO controllers are stable. The performance of the multivariable system is also investigated, and it is shown that the interactions decrease the overall performance of the controlled system. This loss of performance can be reduced by using a feedforward controller. Experimental results show the effectiveness of the method

Strategies to design push-pull osmotic systems for delivering low and pH-dependent soluble drugs

In the recent years, novel oral drug delivery systems have been recognized as an attractive niche for pharmaceutical industry. Among these systems, controlledrelease formulations have been developed based on their significant advantages over conventional immediate release dosage forms, such as the decrease of dosing frequency, the increase of patient compliance, better dosing patterns, the reduction of side effects, or the maintenance of the drug concentration within a desired range, i.e, an overall improved therapeutic benefit. However, oral controlled release formulations are exposed to changing environment during transit through the GI-tract which may affect their performances e.g. physiological factors such as patient age or food-intake. Reported as releasing drug independently of these factors, oral osmotically-driven systems (OODS) have taken an increasing place in the MR field. Using osmotic pressure as driving force, various OODS designs and compositions have been developed and launched..

Gignac Canal

Presented at SCADA and related technologies for irrigation district modernization, II: a USCID water management conference held on June 6-9, 2007 in Denver, Colorado.Includes bibliographical references.Theoretical progress in the domain of open channel automatic control has been achieved in the last decades. Controllers are generally designed with the help of mathematical software and tested on computer simulation models. Nevertheless, a phase of real-time testing appears to be necessary before the full validation allowing wide spread implementations of given automatic controllers. This helps taking into account and solving problems linked to the physical limits of sensors or actuators or to usually neglected phenomenon such as communication delays, faults and model errors. The Gignac canal project aims at addressing this issue and sharing a research platform with diverse industrial and academic partners. It involves mainly the equipment of the canal with sensors and actuators, and an opened SCADA system. It has been designed to make possible the test of a wide range of control architectures and algorithms. The equipment also helps the canal manager facing strengthening management constraints. They appear with the strict application of new legislations which lead to diminish intake withdrawals and to modernize parts of the secondary network. The project associates in a scientific committee: the canal manager, research teams, engineering companies, Universities and Colleges. It helps transferring academic knowledge and focusing the experiments on problem solving and end-users' requirements. Universities and Colleges take benefit from the facilities for practical work for teaching programmes in hydraulics and automatics

Efficacité et tolérance du géfitinib dans le cancer bronchique non à petites cellules / Vincent Malaterre

STRASBOURG ILLKIRCH-Pharmacie (672182101) / SudocSudocFranceF

Analyse de la stabilité et de la performance des méthodes classiques de contrôle décentralisé des canaux d'irrigation

Irrigation canals have a series structure which is generally used to design multivariable controllers based on the aggregation of decentralized monovariable controllers. SISO controllers are designed for each canal pool, assuming that the interactions will not destabilize the overall system. It is shown that, when the canal pools are controlled using the discharge at one boundary, the multivariable decentralized control structure is stable if and only if the SISO controllers are stable. The performance of the multivariable system is also investigated, and it is shown that the interactions decrease the overall performance of the controlled system. This loss of performance can be reduced by using a feedforward controller. Experimental results show the effectiveness of the method

Benchtop-magnetic resonance imaging (BT-MRI) characterization of push-pull osmotic controlled release systems

The mechanism of drug release from push-pull osmotic systems (PPOS) has been investigated by Magnetic Resonance Imaging (MRI) using a new benchtop apparatus. The signal intensity profiles of both PPOS layers were monitored non-invasively over time to characterize the hydration and swelling kinetics. The drug release performance was well-correlated to the hydration kinetics. The results show that (i) hydration and swelling critically depend on the tablet core composition, (ii) high osmotic pressure developed by the push layer may lead to bypassing the drug layer and incomplete drug release and (iii) the hydration of both the drug and the push layers needs to be properly balanced to efficiently deliver the drug. MRI is therefore a powerful tool to get insights on the drug delivery mechanism of push-pull osmotic systems, which enable a more efficient optimization of such formulations

Éthique et innovation thérapeutique

Disposer de médicaments innovants pour soigner les maladies neuromusculaires marque incontestablement un tournant historique. Ce bond en avant scientifique suscite bien des interrogations éthiques, qu’elles concernent la prise en charge des patients, la participation aux essais cliniques ou encore le dépistage néonatal. Autant de pistes de réflexion ouvertes, en trois questions

Commande en dimension finie

Extrait de documentThis book is dedicated to automatic control methods for irrigation canals as well as current research about automatic control of open-channel hydraulic systems. It gives an overview on the approaches developed in the french-speaking scientific community. These research works are motivated by the problem of managing water resources, and by intrincic difficulties linked to these special problems of fluids mechanics.Cet ouvrage est dédié aux méthodes de régulation des canaux d'irrigation ainsi qu'aux recherches en cours dans le domaine de la régulation des systèmes hydrauliques dits à surface libre. Il fait le point sur les approches développées depuis une quinzaine d'années dans la communauté scientifique francophone. Ces travaux sont motivés non seulement par les enjeux de la maîtrise des ressources en eau mais également par les difficultés intrinsèques de ces problèmes particuliers de mécanique des fluides. L'ouvrage est composé de cinq chapitres. Le chapitre 1 présente la problématique générale de la gestion des systèmes hydrauliques à surface libre. Le chapitre suivant expose les différents types de modèles qui ont été développés et utilisés pour les systèmes hydrauliques à surface libre. Le chapitre 3 propose différentes méthodes de commande en temps réel des systèmes hydrauliques à surface libre, dans le contexte de la dimension finie. Le chapitre 4 offre des perspectives sur la commande en dimension infinie. Il s'attache à présenter des résultats récents sur l'analyse et la commande. Enfin, le chapitre 5 développe quelques exemples de systèmes hydrauliques à surface libre

Commande en dimension finie

Extrait de documentThis book is dedicated to automatic control methods for irrigation canals as well as current research about automatic control of open-channel hydraulic systems. It gives an overview on the approaches developed in the french-speaking scientific community. These research works are motivated by the problem of managing water resources, and by intrincic difficulties linked to these special problems of fluids mechanics.Cet ouvrage est dédié aux méthodes de régulation des canaux d'irrigation ainsi qu'aux recherches en cours dans le domaine de la régulation des systèmes hydrauliques dits à surface libre. Il fait le point sur les approches développées depuis une quinzaine d'années dans la communauté scientifique francophone. Ces travaux sont motivés non seulement par les enjeux de la maîtrise des ressources en eau mais également par les difficultés intrinsèques de ces problèmes particuliers de mécanique des fluides. L'ouvrage est composé de cinq chapitres. Le chapitre 1 présente la problématique générale de la gestion des systèmes hydrauliques à surface libre. Le chapitre suivant expose les différents types de modèles qui ont été développés et utilisés pour les systèmes hydrauliques à surface libre. Le chapitre 3 propose différentes méthodes de commande en temps réel des systèmes hydrauliques à surface libre, dans le contexte de la dimension finie. Le chapitre 4 offre des perspectives sur la commande en dimension infinie. Il s'attache à présenter des résultats récents sur l'analyse et la commande. Enfin, le chapitre 5 développe quelques exemples de systèmes hydrauliques à surface libre