Une division du travail contrainte produite par l’anticipation d’une situation anomique ? Une analyse néo-durkheimienne de la loi HADOPI et des pratiques de téléchargement illégal de musique

En France, la question du non-respect des droits d’auteur en matière de musique a été indissociablement un problème politique, aboutissant à la création de l’HADOPI et un problème scientifique. À rebours des analyses juridiques, économiques, de gestion ou de management, qui soulignent les attitudes réalistes des consommations illégales de musique (soit pour les criminaliser, soit pour que les industries en tirent profit), nous adoptons la perspective néo-durkheimienne élaborée par Cyril Lemieux et focalisons l’attention sur le caractère moral de telles pratiques. En nous appuyant sur l’enquête statistique des pratiques culturelles des Français de 2008 et sur une enquête qualitative de consommateurs de musique, nous soutenons que l’HADOPI, en considérant comme stratégiques les attitudes critiques des consommateurs qui, en fait, revendiquent à leur égard un plus grand respect de la règle d’équité, a produit une situation de division du travail contrainte, en pensant lutter contre une situation anomique.

Role of irradiation and irradiation defects on the oxidation first stages of a 316L austenitic stainless steel

The role of irradiation and irradiation defects on the oxidation first stages of 316 L alloy was investigated. A sample with both a proton pre-irradiated and an unirradiated area was exposed to a simulated PWR environment during 24 hours. Irradiation defects and Radiation Induced Segregation at grain boundary and on irradiation defects were characterized and quantified and their effect on the oxidation was evaluated. Irradiation affects the morphology, thickness and chemistry of the oxide layers formed. It enhances the oxidation kinetic and induces the formation of an inner oxide richer in chromium. Defects induced by irradiation act as preferential nucleation sites

Integrated piezoelectric function in a high thermostable thermoplastic PZT/PEEK composite

A piezoelectric structural material has been developed. Lead Zirconate Titanate (PZT) submicronic nanoparticles have been dispersed in a thermostable high performance thermoplastic polymer Poly(Ether Ether Ketone) i.e. PEEK to ensure piezoelectric properties. The inorganic particles with a mean diameter of 900 nmare polycrystalline as highlighted by HRTEM with a grain diameter estimated at 15 nm. XRD patterns have shown that the crystalline structure is rhombohedral i.e. ferroelectric. The PZT/PEEK composites have been elaborated by extrusion which allows reaching a satisfactory dispersion of particles even at high volume fraction (30% in volume). One of the challenges was to find poling conditions compatible with the thermal stability of the matrix. Indeed, this composite must be poled above the polymer glass transition temperature to improve matching of dielectric permittivity between inorganic and organic phases. The influence of the poling electric field on the final piezoelectric activity of the composite has also been studied to better understand the role of the polymer matrix. Finally, after a poling step, the PZT/PEEK composite exhibits a piezoelectric strain coefficient which can be exploited over a wide temperature range

Tilted Fiber Bragg Grating photowritten in microstructured optical fiber for improved refractive index measurement

International audienceWe report what we believe to be the first Tilted short-period Fiber Bragg Grating photowritten in a microstructured optical fiber for refractive index measurement. We investigate the spectral sensitivity of Tilted Fiber Bragg Grating to refractive index liquid inserted into the holes of a multimode microstructured fiber. We measure the wavelength shift of the first four modes experimentally observed when calibrated oils are inserted into the fiber holes, and thus we determine the refractive index resolution for each of these modes. Moreover, a cross comparison between experimental and simulation results of a modal analysis is performed. Two simulation tools are used, respectively based on the localized functions method and on a finite element method. All results are in very good agreement

Towards antenna miniaturization at radio frequencies using plasma discharges

An original electrically small antenna concept relying on plasma discharges is presented in this paper. It consists of a small coaxial probe placed above a ground plane and surrounded by a hemispherical inductively coupled plasma discharge. This plasma discharge behaves as a subwavelength epsilon-negative resonator exhibiting a localized surface plasmon resonance at microwave frequencies with significant radiation efficiency. Measurements show that the plasma allows impedance matching of the radiating element and frequency agility from 310 to 390 MHz by controlling the power delivered to the discharge. Meanwhile, significant radiation enhancement up to 20 dB at 300 MHz is measured. The existence of the localized surface plasmon resonance is finally confirmed by a Mie analysis considering the measured plasma characteristics

Utilisation de la résonance plasmonique de surface d'une décharge plasma pour la conception d’antennes miniatures accordables.

Cette communication présente un concept original d'antenne miniature reposant sur des plasmas de décharge. Cette antenne consiste en une petite sonde coaxiale placée au-dessus d'un plan de masse et entourée d'un plasma hémisphérique. Ce plasma se comporte alors comme un résonateur à permittivité diélectrique négative présentant une résonance plasmonique de surface aux fréquences microondes. Les mesures montrent que le plasma permet une adaptation d'impédance de l’antenne miniature ainsi qu'une agilité en fréquence de 310 à 390 MHz. Une augmentation significative du rayonnement est aussi mise en évidence. Enfin, l’existence de la résonance plasmonique de surface est confirmée par une analyse de Mie tenant compte des caractéristiques mesurées du plasma

A harmonic oscillator model to study the intensification of microwave radiation by a subwavelength uniform plasma discharge

A harmonic oscillator model is proposed to study the intensification of microwave radiation of an electrically small antenna when surrounded by a subwavelength plasma discharge. This model describes the oscillations of free electrons in a spherical plasma when it is excited by an incident electromagnetic wave. It shows that at resonance, these charge oscillations lead to a significant volume current, and thus to an enhancement of the radiation. Depending on the electron density of the plasma, this radiation enhancement may occur in the microwave range. The proposed model is compared with the Mie scattering theory with perfect agreement when the electrical size ka of the spherical plasma remains smaller than 0.1. Despite its apparent simplicity, this model unveils the main mechanism that stands behind the intensification of microwave radiation by a subwavelength plasma discharge

Experimental and numerical studies of the plasmonic resonance of a low-pressure hemispherical plasma discharge in the upper VHF band

This paper aims to present investigations of the plasmonic resonance of a hemispherical plasma discharge in the high VHF band. First, this plasmonic resonance is experimentally studied by illuminating the plasma discharge with an incident plane wave and by measuring its response using a coaxial probe located directly inside the plasma. In order to validate the experimental results, a numerical study is then proposed by coupling plasma and electromagnetic simulations

Nonlinear Effects of Electromagnetic Pulse on a Plasma-Based Electrically Small VHF Antenna

Demonstration of the electromagnetic hardening properties of a plasma-based electrically small VHF antenna is presented in this paper. It is shown that when illuminated by an electromagnetic pulse, the maximum voltage collected by the antenna grows linearly with the maximum magnitude of the incident electric field, but beyond a certain threshold around 70 kV/m, the maximum voltage collected ceases to grow linearly and seems to saturate around a value of 200 V

Design of a Tunable Subwavelength Plasma-Based Resonator for Electrically Small Antenna Applications in L-band

A preliminary study of the design of an electrically small plasma-based resonator using a localized surface plasmon resonance (LSPR) above 1 GHz is presented. Such a resonator is intended to be used to develop an electrically small antenna with frequency agility. This resonator consists of a plasma discharge confined in a hemispherical glass shell 3 cm in diameter on a ground plane. From 1 to 1.5 GHz, the plasma electron density required to achieve the LSPR must be between 0.5 × 1011 and 1.4×1011 cm−3. Plasma losses are taken into account in this study and provide information on the required gas pressure. Typically for neon gas, the working pressure must be around 50 mTorr. A practical implementation using a miniature inductively coupled plasma (mICP) source is finally discussed