Impact of the aging of a photovoltaic module on the performance of a grid-connected system

Photovoltaic systems belong to the green energy dynamics which is an ambitious program based on energy efficiency and sustainable development. In this study, the impact of the aging of a photovoltaic module is investigated on the electrical performance of a grid-connected system. A photovoltaic conversion chain with MPPT (Maximum Power Point Tracking) control and LC (Inductor-Capacitor) filter is modeled and dimensioned according to the grid constraints. A method of hybridation detection of the MPPT coupling long-time aging evolution and short-time determination is proposed. Aging laws for the electrical and optical degradations of the photovoltaic module are introduced for the long-time evolution. Results display the lowering of the maximal power point with a rate of 1%/year and a slight augmentation of the THD over time even though it remains inferior to the IEEE standard STD 19-1992 maximum value of 5% for a usage of 20 years. Moreover, an equivalent scheme for the additional electrical resistance engendered by the aging of the photovoltaic module regarding other resistances of the photovoltaic system is given. Finally, the elevation of this resistance by 12.8% in 20 years may have non-negligible consequences on the power production of a large-scale installation. © 201

Plasma membrane depolarization induced by abscisic acid in Arabidopsis suspension cells involves reduction of proton pumping in addition to anion channel activation, which are both Ca2+ dependent

In Arabidopsis suspension cells a rapid plasma membrane depolarization is triggered by abscisic acid (ABA). Activation of anion channels was shown to be a component leading to this ABA-induced plasma membrane depolarization. Using experiments employing combined voltage clamping, continuous measurement of extracellular pH, we examined whether plasma membrane H(+)-ATPases could also be involved in the depolarization. We found that ABA causes simultaneously cell depolarization and medium alkalinization, the second effect being abolished when ABA is added in the presence of H(+) pump inhibitors. Inhibition of the proton pump by ABA is thus a second component leading to the plasma membrane depolarization. The ABA-induced depolarization is therefore the result of two different processes: activation of anion channels and inhibition of H(+)-ATPases. These two processes are independent because impairing one did not suppress the depolarization. Both processes are however dependent on the [Ca(2+)](cyt) increase induced by ABA since increase in [Ca(2+)](cyt) enhanced anion channels and impaired H(+)-ATPases

OX40L blockade protects against inflammation-driven fibrosis.

Treatment for fibrosis represents a critical unmet need, because fibrosis is the leading cause of death in industrialized countries, and there is no effective therapy to counteract the fibrotic process. The development of fibrosis relates to the interplay between vessel injury, immune cell activation, and fibroblast stimulation, which can occur in various tissues. Immunotherapies have provided a breakthrough in the treatment of immune diseases. The glycoprotein OX40-OX40 ligand (OX40L) axis offers the advantage of a targeted approach to costimulatory signals with limited impact on the whole immune response. Using systemic sclerosis (SSc) as a prototypic disease, we report compelling evidence that blockade of OX40L is a promising strategy for the treatment of inflammation-driven fibrosis. OX40L is overexpressed in the fibrotic skin and serum of patients with SSc, particularly in patients with diffuse cutaneous forms. Soluble OX40L was identified as a promising serum biomarker to predict the worsening of lung and skin fibrosis, highlighting the role of this pathway in fibrosis. In vivo, OX40L blockade prevents inflammation-driven skin, lung, and vessel fibrosis and induces the regression of established dermal fibrosis in different complementary mouse models. OX40L exerts potent profibrotic effects by promoting the infiltration of inflammatory cells into lesional tissues and therefore the release of proinflammatory mediators, thereafter leading to fibroblast activation

On the Runtime Enforcement of Timed Properties

International audienceRuntime enforcement refers to the theories, techniques, and tools for enforcing correct behavior of systems at runtime. We are interested in such behaviors described by specifications that feature timing constraints formalized in what is generally referred to as timed properties. This tutorial presents a gentle introduction to runtime enforcement (of timed properties). First, we present a taxonomy of the main principles and concepts involved in runtime enforcement. Then, we give a brief overview of a line of research on theoretical runtime enforcement where timed properties are described by timed automata and feature uncontrollable events. Then, we mention some tools capable of runtime enforcement, and we present the TiPEX tool dedicated to timed properties. Finally, we present some open challenges and avenues for future work. Runtime Enforcement (RE) is a discipline of computer science concerned with enforcing the expected behavior of a system at runtime. Runtime enforcement extends the traditional runtime verification [12-14, 42, 43] problem by dealing with the situations where the system deviates from its expected behavior. While runtime verification monitors are execution observers, runtime enforcers are execution modifiers. Foundations for runtime enforcement were pioneered by Schneider in [98] and by Rinard in [95] for the specific case of real-time systems. There are several tutorials and overviews on runtime enforcement for untimed systems [39, 47, 59], but none on the enforcement of timed properties (for real-time systems). In this tutorial, we focus on runtime enforcing behavior described by a timed property. Timed properties account for physical time. They allow expressing constraints on the time that should elapse between (sequences of) events, which is useful for real-time systems when specifying timing constraints between statements, their scheduling policies, the completion of tasks, etc [5, 7, 88, 101, 102]. This tutorial comprises four stages: 1. the presentation of a taxonomy of concepts and principles in RE (Sec. 1); 2. the presentation of a framework for the RE of timed properties where specifications are described by timed automata (preliminary concepts are recalled in Sec. 2, the framework is overviewed in Sec. 3, and presented in more details in Sec. 4); 3. the demonstration of the TiPEX [82] tool implementing the framework (Sec. 5); 4. the description of some avenues for future work (Sec. 6)