Search results for "COU"
showing 10 items of 14566 documents
De barrio-problema a barrio de moda: gentrificación comercial en Russa-fa, El “Soho” valenciano
2015
Russafa neighborhood in Valencia (Spain) has become the center of one of the most ambitious urban redevelopment plans implemented by the local council in recent years. This old neighborhood of merchants and artisans, that during the 80's and 90’s experienced a long period of degradation and neglect, is today the multicultural trendy district for tourists and citizens The aim of this paper is to show the gentrification process emerged in this neighborhood, and how from the abandonment that characterized it just a decade ago, it has undergone a fast process of festivalization and economic transformation with the arrival of the “creative classes”, that so far has caused few reactions, despite …
Do Vulnerable Youth Dream Of Precarious Employment? Decision Making at (In/Ex) clusion Pathways
2015
Este trabajo aborda el análisis de los discursos de jóvenes que han tenido dificultades en su itinerario educativo y que han participado en “itinerarios de segunda oportunidad”. A partir de entrevistas a jóvenes, pretendemos aproximarnos a los argumentos desde los que dan sentido a sus itinerarios académicos y a las decisiones a las que se han enfrentado. Estos argumentos muestran fuertes implicaciones de la posición social de los actores, y están influidos por agentes de la institución educativa y familiar. En ese marco los jóvenes van configurando unas expectativas de futuro. Estas expectativas se debaten entre tres vías: salidas a espacios laborales poco cualificados y precarios, aunque …
Profesorado : revista de curriculum y formación del profesorado
2015
Este trabajo aborda el análisis de los discursos de jóvenes que han tenido dificultades en su itinerario educativo y que han participado en 'itinerarios de segunda oportunidad'. A partir de entrevistas a jóvenes, pretendemos aproximarnos a los argumentos desde los que dan sentido a sus itinerarios académicos y a las decisiones a las que se han enfrentado. Estos argumentos muestran fuertes implicaciones de la posición social de los actores, y están influidos por agentes de la institución educativa y familiar. En ese marco los jóvenes van configurando unas expectativas de futuro. Estas expectativas se debaten entre tres vías: salidas a espacios laborales poco cualificados y precarios, aunque …
Nocardiosis complicated with Addison's disease
2011
A 77-year-old woman presented with subacute respiratory symptoms which were demonstrated to be due to nocardiosis. After initial improvement with antimicrobial therapy, new symptoms appeared, consisting of persistent vomits, abdominal pain and hypotension, which led to the diagnosis of Addison's disease.
Mechanical, thermal and acoustical characterizations of an insulating bio-based composite made from sunflower stalks particles and chitosan
2014
International audience; This study has for objective the determination of thermal, mechanical and acoustical properties of insulating bio-based composite made with chitosan and sunflower's stalks particles. An experimental design was established to find the size grading of particles, the ratio chitosan/sunflower particles and the stress of compaction influencing the thermal and mechanical properties. Composites with a thermal conductivity $(\kappa)$ of 0.056 W/m/K, a maximum stress $(\sigma_{\text{max}})$ of 2 MPa and an acoustic coefficient of absorption $(\alpha)$ of 0.2 were obtained with a ratio of chitosan of 4.3% (w/w) and a size grading of particles higher to 3 mm. These mechanical a…
Sound conversion phenomena at the free surface of liquid helium. I. Calculation of the coefficients of reflection, transmission, and transformation o…
1980
On the basis of a set of boundary conditions describing quite generally mass and energy transport processes across the free surface of helium II, the acoustic coefficients of reflection, transmission, and transformation of first sound, second sound, and the sound wave propagating in the vapor are calculated in the case of perpendicular incidence of sound waves against the liquid-vapor phase boundary. Considering rigorously the influences of the Onsager surface coefficients, the isobaric thermal expansion coefficients, and the thermal conductivities of the liquid and the vapor, we derive sets of equations from which the acoustic coefficients are determined numerically. For estimations, simpl…
On the variations of acoustic absorption peak with particle velocity in micro-perforated panels at high level of excitation.
2010
The acoustic behavior of micro-perforated panels (MPP) is studied theoretically and experimentally at high level of pressure excitation. A model based on Forcheimer's regime of flow velocity in the perforations is proposed. This model is valid at relatively high Reynolds numbers and low Mach numbers. The experimental method consists in measuring the acoustical pressure at three different positions in an impedance tube, the two measurement positions usually considered in an impedance tube and one measurement in the vicinity of the rear surface of the MPP. The impedance tube is equipped with a pressure driver instead of the usual loudspeaker and capable of delivering a high sound pressure lev…
Acoustic characterization of Silica aerogel clamped plates for perfect absorption purpose
2017
International audience; Silica aerogel has been widely studied as bulk material for its extremely low density and thermal conductivity. Plates or membranes made of this extremely soft materials exhibits interesting properties for sound absorption. A novel signal processing method for the characterization of an acoustic metamaterial made of silica aerogel clamped plates is presented. The acoustic impedance of a silica aerogel clamped plate is derived from the elastic theory for the flexural waves, while the transfer matrix method is used to model reflection and transmission coefficients of a single plate. Experimental results are obtained by using an acoustic impedance tube. The difference b…
Experimental investigation of holes interaction effect on the sound absorption coefficient of micro-perforated panels under high and medium sound lev…
2011
Abstract This paper experimentally investigates the holes interaction effect on the sound absorption coefficient of micro-perforated panels under high and medium sound levels. The theoretical formulations are based on a semi-empirical approach and the use of Fok’s function to model the acoustic surface impedance. For the high sound level regime, an empirical power law involving three coefficients is adapted. It is shown theoretically and experimentally that these coefficients can lead to optimized absorption performance and particularly, a formula relating the critical Reynolds number (Reynolds number value after which the absorption coefficient decreases with the increase of sound level) a…
Investigation of molecular dimers by ensemble and single molecule spectroscopy
2002
International audience; We have investigated molecular dimers with different electronic coupling strengths by bulk and single molecule spectroscopy. In one of the dimers the two monomers (perylene-monoimide) are directly connected via a single bond while in the other one they are separated by the benzil motif. The close proximity of the monomers in the first case gives rise to excitonic band splitting which is clearly observable in the bulk absorption spectra. For the benzil structure the electronic interactions are governed by Förster-type energy hopping between the monomers. Fluorescence intensity trajectories at the single molecule level show one-step and two-step bleaching behaviour whi…