Real-time simulation and hardware-in-the-loop approaches for integrating renewable energy sources into smart grids : challenges & actions

The integration of distributed renewable energy sources and the multi-domain behaviours inside the cyber-physical energy system (smart grids) draws up major challenges. Their validation and roll out requires careful assessment, in term of modelling, simulation and testing. The traditional approach focusing on a particular object, actual hardware or a detailed model, while drastically simplifying the remainder of the system under test, is no longer sufficient. Real-time simulation and Hardware-in-the-Loop (HIL) techniques emerge as indispensable tools for validating the behaviour of renewable sources as well as their impact/interaction to with the cyber-physical energy system. This paper aims to provide an overview of the present status-quo of real-time and HIL approaches used for smart grids and their readiness for cyber-physical experiments. We investigate the current limitations of HIL techniques and point out necessary future developments. Subsequently, the paper highlights challenges that need specific attention as well as ongoing actions and further research directions

Study of Rare Corrosion Forms Found in a Karst Syphon

The aim of this article is to describe two-dimensional scallops (scallops guided inside ribs) found in a syphon, to compare them to the ordinary three-dimensional corrosion forms frequently found in karst systems (scallops and flutes). We also raise a certain number of questions regarding analogical and numerical modeling. The syphon is named “Combe du Creux” (department of the Doubs, France, EU). We have been exploring this flooded cave since 2003. Since 2015, we are studying its morphology and especially its scallops. When diving underwater underground (cave diving), observation work is more difficult. Therefore, photographs of the forms, of the tools used to measure them, have been made in order to be processed afterwards. The ordinary scallops found at four locations inside the cave have been documented, as well as two-dimensional scallops found at a fifth location. Very likely, these particular scallops have formed inside pre-existing ribs. They seem, from a qualitative point of view, to behave like ordinary scallops: they have qualitatively the same profile and obey the Curl relationship. However, regarding details, differences appear and lead to new questions about the formation and evolution of scallops: what is the influence of the material (kinetic and diffusion coefficients)? Of the flow rate? Of the boundary conditions? Ultimately, we insist on the fact that studying scallops in caves or modeling them is still an open field

Cave Diving: Results of the Exploration of the “Combe du Creux”

This article deals with speleology applied to the exploration of a siphon named “Combe du Creux”. It is located in France, in the department of the Doubs. We present surveys and the specific forms that are encountered in this flooded cave; eventually we propose a possible evolution of this sump. Cave diving, regarded as cave science, closely associated to underwater photography, is a good mean to investigate such a cave. We have been diving in this sump since 2003 and we present the results of 13 years of explorations, up to July 2016. After having explored this cave up to the farthest known point, we made a survey (elevation and plane view). Further dives, using a rebreather when necessary, enabled a work of observation and underwater photography. We observed concretions – limestone as well as clay – and potholes below the current water level. We also observed ribs and scallops. The underground development of the cave seems well correlated with geologic elements that can be observed outside. The set of all the observations leads to the conclusion that, at long time scale, the water level has fluctuated. It has been, at least once, 46 m (151 ft) below its current position. In one place inside the cave, it has been observed interactions between flutes and scallops: this new information should be taken in account in any new theoretical or computational modeling of scallops

Cave Diving: Results of the Exploration of the “Combe du Creux”

This article deals with speleology applied to the exploration of a siphon named “Combe du Creux”. It is located in France, in the department of the Doubs. We present surveys and the specific forms that are encountered in this flooded cave; eventually we propose a possible evolution of this sump. Cave diving, regarded as cave science, closely associated to underwater photography, is a good mean to investigate such a cave. We have been diving in this sump since 2003 and we present the results of 13 years of explorations, up to July 2016. After having explored this cave up to the farthest known point, we made a survey (elevation and plane view). Further dives, using a rebreather when necessary, enabled a work of observation and underwater photography. We observed concretions – limestone as well as clay – and potholes below the current water level. We also observed ribs and scallops. The underground development of the cave seems well correlated with geologic elements that can be observed outside. The set of all the observations leads to the conclusion that, at long time scale, the water level has fluctuated. It has been, at least once, 46 m (151 ft) below its current position. In one place inside the cave, it has been observed interactions between flutes and scallops: this new information should be taken in account in any new theoretical or computational modeling of scallops

Modeling the Dynamics of Flutes and Scallops: Preliminary Results

Our aim is to develop a computational model of the corrosion forms known as scallops and flutes, common in karst environment. This model is designed to take in account dynamical interactions between successive forms, which has previously never be done, and to be as simple as possible. We present preliminary results corresponding to numerical simulations that have been run during February 2018. The evolution of scallops and flutes is summarized in some simple equations that model how the length of a form evolves, how too large forms split into smaller forms and how too small forms are erased by larger ones. These equations are used in programs written in C language. They enable to investigate how a system of numerous scallops or flutes evolves and to investigate the corresponding statistical distribution. The preliminary results we present are very encouraging because of their good quantitative agreement with the well-known Curl relationship in the case of steady flows. When the velocity of the water (or air) responsible for the formation of scallops or flutes change, the model predicts that the average size of the forms changes too. However, in such a situation, the Curl relationship is not always accurately verified. This progressive model depends upon few parameters and does not require huge computing power. Further comparisons with field data may render it even more realistic, particularly regarding the statistical distributions it generates

CALCUL DES PERFORMANCES D'UN LASER CO2 A EXCITATION ÉLECTRIQUE. COMPARAISON AVEC L'EXPÉRIENCE

En utilisant les vitesses d'excitation vibrationnelle calculées à partir de la fonction de distribution des électrons et les équations de relaxation d'un système moléculaire à 3 températures de vibration, on calcule le coefficient d'amplification et l'énergie pouvant être extraite du milieu amplificateur. Quelques résultats expérimentaux obtenus sur un laser à préionisation par faisceau d'électrons sont présentés.Calculation of laser beam amplification and laser output power have been made by resolving the vibrational relaxation equations of a molecular system characterized by three vibrational temperatures. The electron vibrational excitation rates are obtained from numerical calculation of the electron distribution function. Preliminary laser output measurements on an e-beam controlled discharge CO2 laser indicate good agreement between theoretical prediction and experiment

In vivo gene transfer into the ocular ciliary muscle mediated by ultrasound and microbubbles.

This study aimed to assess application of ultrasound (US) combined with microbubbles (MB) to transfect the ciliary muscle of rat eyes. Reporter DNA plasmids encoding for Gaussia luciferase, β-galactosidase or the green fluorescent protein (GFP), alone or mixed with 50% Artison MB, were injected into the ciliary muscle, with or without US exposure (US set at 1 MHz, 2 W/cm(2), 50% duty cycle for 2 min). Luciferase activity was measured in ocular fluids at 7 and 30 days after sonoporation. At 1 week, the US+MB treatment showed a significant increase in luminescence compared with control eyes, injected with plasmid only, with or without MB (×2.6), and, reporter proteins were localized in the ciliary muscle by histochemical analysis. At 1 month, a significant decrease in luciferase activity was observed in all groups. A rise in lens and ciliary muscle temperature was measured during the procedure but did not result in any observable or microscopic damages at 1 and 8 days. The feasibility to transfer gene into the ciliary muscle by US and MB suggests that sonoporation may allow intraocular production of proteins for the treatment of inflammatory, angiogenic and/or degenerative retinal diseases

LABELLED PROOF SYSTEMS FOR INTUITIONISTIC provability

In this paper, we propose new labelled proof systems to analyse the intuitionistic provability in classical and linear logics. An important point is to understand how search in a non-classical logic can be viewed as a perturbation of search in classical logic. Therefore, suitable characterizations of intuitionistic provability and related labelled sequent calculi are defined for linear logic. An alternative approach, based on the notion of proof-net and on the definition of suitable labelled classical proof-nets, allows to directly study the intuitionistic provability by constructing intuitionistic proof-nets for sequents of classical linear logic