Récupération d'énergie à partir des vibrations ambiantes (dispositif électromagnétique et circuit électronique d'extraction synchrone)

La récupération d énergie vise à réaliser des dispositifs électromécaniques de taille centimétrique permettant d alimenter des systèmes électroniques en puisant de manière opportuniste l énergie du milieu environnant. Parmi les différentes sources disponibles (solaire,thermique etc.) les vibrations ambiantes sont susceptibles de fournir assez de puissance pour alimenter des microsystèmes autonomes tels que des noeuds de réseaux de capteurs communicants. L enjeu consiste à concevoir des microgénérateurs effectuant la conversion de cette énergie mécanique ambiante en énergie électrique exploitable de manière optimale.Ces travaux de thèse proposent dans un premier temps un critère d étude et de comparaison des performances des générateurs de types piézoélectriques ou électromagnétiques, à partir d un modèle normalisé unifié. Dans un second temps, un circuit non linéaire d extraction de l énergie est étudié pour les générateurs électromagnétiques, et ses performances sont discutées en comparaison avec un circuit classique d extraction de l énergie. A partir de ces résultats, une nouvelle structure de générateur électromagnétique est conçue, optimisée puis validée expérimentalement.Energy harvesting from ambient energy aims at realizing electromechanical miniaturized generators to supply electronic systems from energy of our local environment. Among the available sources (solar, thermal ), ambient vibrations show the requirements to supply autonomous microsystems like communication sensors nodes of sensors networks. The issue is to develop microgenerators doing the optimal conversion of the mechanical energy into usable electrical energy, and supplying the maximal power density. This works presents a criterium to compare piezoelectric systems and electromagnetic systems, based on a common normalized model. In a second part, a new nonlinear extraction circuit for electromagnetic generators is theoretically studied, and its practical advantages are highlighted in comparison with a classical extraction circuit. Based on these results, a new structure of electromagnetic generator is studied,optimized and experimentally validated.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

H19 Antisense RNA Can Up-Regulate Igf2 Transcription by Activation of a Novel Promoter in Mouse Myoblasts

It was recently shown that a long non-coding RNA (lncRNA), that we named the 91H RNA (i.e. antisense H19 transcript), is overexpressed in human breast tumours and contributes in trans to the expression of the Insulin-like Growth Factor 2 (IGF2) gene on the paternal chromosome. Our preliminary experiments suggested that an H19 antisense transcript having a similar function may also be conserved in the mouse. In the present work, we further characterise the mouse 91H RNA and, using a genetic complementation approach in H19 KO myoblast cells, we show that ectopic expression of the mouse 91H RNA can up-regulate Igf2 expression in trans despite almost complete unmethylation of the Imprinting-Control Region (ICR). We then demonstrate that this activation occurs at the transcriptional level by activation of a previously unknown Igf2 promoter which displays, in mouse tissues, a preferential mesodermic expression (Pm promoter). Finally, our experiments indicate that a large excess of the H19 transcript can counteract 91H-mediated Igf2 activation. Our work contributes, in conjunction with other recent findings, to open new horizons to our understanding of Igf2 gene regulation and functions of the 91H/H19 RNAs in normal and pathological conditions

Performance of a large scale prototype of the ATLAS accordion electromagnetic calorimeter

A 2 m long prototype of a lead-liquid argon electromagnetic calorimeter with accordion-shaped electrodes, conceived as a sector of the barrel calorimeter of the future ATLAS experiment at the LHC, has been tested with electron and pion beams in the energy range 10 to 287 GeV. A sampling term of 10%/root E(GeV) was obtained for electrons in the rapidity range 0 < eta < 1, while the constant term measured over an area of about 1 m(2) is 0.69%. With a cell size of 2.7 cm the position resolution is. about 4 mm/root E(GeV)

Construction and test of a fine-grained liquid argon preshower prototype

A separate liquid argon preshower detector consisting of two layers featuring a fine granularity of 2.5~10$^{\mathrm{-3}}$ was studied by the RD3 collaboration. A prototype covering approximately 0.8 in pseudo-rapidity and 9 degrees in azimuth was built and tested at CERN in July 94. CMOS and GaAs VLSI preamplifiers were designed and tested for this occasion. The combined response of this detector and an accordion electromagnetic calorimeter prototype to muons, electrons and photons is presented. For minimum ionizing tracks a signal-to-noise ratio of 4.5 per preshower layer was measured. Above 150~GeV the space resolution for electrons is better than 250~$\mu$m in both directions. The precision on the electromagnetic shower direction, determined together with the calorimeter, is better than 4 mrad above 50~GeV. It is concluded that the preshower detector would adequately fulfil its role for future operation at CERN Large Hadron Collider

Performance of an endcap prototype of the ATLAS accordion electromagnetic calorimeter

The design and construction of a lead-liquid argon endcap calorimeter prototype using an accordion geometry and conceived as a sector of the inner wheel of the endcap calorimeter of the future ATLAS experiment at the LHC is described. The performance obtained using electron beam data is presented. The main results are an energy resolution with a sampling term below $11\%/\sqrt{E(\rm GeV)}$ and a small local constant term, a good linearity of the response with the incident energy and a global constant term of 0.8\% over an extended area in the rapidity range of $2.2 < \eta <2.9$. These properties make the design suitable for the ATLAS electromagnetic endcap calorimeter

Test beam results of a stereo preshower integrated in the liquid argon accordion calorimeter

This paper describes the construction of an integrated preshower within the RD3 liquid argon accordion calorimeter. It has a stereo view which enables the measurement of two transverse coordinates. The prototype was tested at CERN with electrons, photons and muons to validate its capability to work at LHC ( Energy resolution, impact point resolution, angular resolution, $\pi^o$/$\gamma$ rejection )

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

EDEN3 : Dispositif pédagogique pour l'enseignement à distance en dernière année d'école d'ingénieur retour d'expérience et positionnement stratégique

International audienc