Jean-Philippe Bras, Larbi Chouikha, dirs, Médias et technologies de communication au Maghreb et en Méditerranée. Mondialisation, redéploiement et « arts de faire »

L’ouvrage rassemble les contributions de chercheurs qui, lors d’un séminaire (Tunis, 6-7 oct. 2000), avaient été invités à dresser un état des lieux des stratégies, mises en œuvre par les pays arabes, pour s’adapter et réagir à l’internationalisation du paysage médiatique. En effet, l’avènement de l’Internet et la transgression – de plus en plus flagrante – des frontières géographiques par les images satellitaires, amènent les pouvoirs politiques à craindre de perdre leur emprise sur les cont..

Ioanna Vovou, dir., Les médias en Grèce

Dresser un état des lieux de la situation des médias grecs et comprendre leur fonctionnement, telles sont les tâches que se sont fixées les auteurs du dossier spécial consacré aux médias helléniques, publié dans la revue Mésogeios. Dans cette livraison, il n’est pas question d’aborder les médias dans une acception qui sous-entendrait qu’ils disposent d’un pouvoir absolu, comme s’ils agissaient en se positionnant en dehors du corps social, voire au-dessus de lui ; il n’est pas question non plu..

Abdelkrim Hizaoui, Addalil attadribi hawla houqouq al insan lil i’lamiyyine

La bibliographie arabe s’est enrichie d’une publication destinée à promouvoir la culture des droits de l’homme chez les journalistes et les professionnels des médias : il s’agit d’un ouvrage intitulé Guide pratique sur les droits de l’homme pour les professionnels des médias, édité par l’Institut arabe des droits de l’homme (IADH) et rédigé par Abdelkrim Hizaoui, Professeur à l’Institut de presse et des sciences de l’information de Tunis. Publié en langue arabe, le livre part du postulat que ..

Ioanna Vovou, dir., Les médias en Grèce

Dresser un état des lieux de la situation des médias grecs et comprendre leur fonctionnement, telles sont les tâches que se sont fixées les auteurs du dossier spécial consacré aux médias helléniques, publié dans la revue Mésogeios. Dans cette livraison, il n’est pas question d’aborder les médias dans une acception qui sous-entendrait qu’ils disposent d’un pouvoir absolu, comme s’ils agissaient en se positionnant en dehors du corps social, voire au-dessus de lui ; il n’est pas question non plu..

The number of blade effects on the performance of a mixed turbine rotor

Turbochargers have become widely applied to diesel vehicle engines. The mixed flow turbine type is suitable for systems where compact power sources are required with higher boost pressure. The sensitivity of the rotor to incidence effects and tendency of the flow to separate have given rise to considerations of the optimum number of blades. This paper investigates the performance of a mixed inflow turbine under steady conditions with the effect of the blade number. This study deals with the determination of the performance characteristics of a mixed flow turbine by solving numerically the 3D Reynolds averaged Navier-Stokes equations. The ANSYSICEM software is used to build the geometry and generate the unstructured meshes while the ANSYS-CFX code is used to simulate the flow in the mixed flow turbine. The numerical method is also used to determine optimum geometrical characteristics such as the optimum number of blades. It has been found that the rotor with 14 blades exhibits better performance

Computational aerodynamic performance of mixed-flow turbine blade design

The performance of two mixed flow turbocharger turbine rotors is numerically investigated. Significantly, the two rotors differ mainly in their inlet angle geometry, one has a constant blade angle (rotor A) and the other has a nominal constant incidence angle (rotor B). Since experimental data alone are not sufficient for understanding the detailed flow field within the turbocharger turbine stage, a complete 3-D Computational Fluid Dynamics model is developed using commercial software Ansys CFX. The model is validated against experimental data for all steady conditions. This study presents a numerical performance prediction of two mixed flow turbine rotors for a wide range of rotational speeds and pressure ratios. The influence of inlet blade angle on the turbine performances is also investigated

A numerical analysis of pollutant dispersion in street canyon: influence of the turbulent Schmidt number

Realizing the growing importance and availability of motor vehicles, we observe that the main source of pollution in the street canyons comes from the dispersion of automobile engine exhaust gas. It represents a substantial effect on the micro-climate conditions in urban areas. Seven idealized-2D building configurations are investigated by numerical simulations. The turbulent Schmidt number is introduced in the pollutant transport equation in order the take into account the proportion between the rate of momentum turbulent transport and the mass turbulent transport by diffusion. In the present paper, we attempt to approach the experimental test results by adjusting the values of turbulent Schmidt number to its corresponding application. It was with interest that we established this link for achieving our objectives, since the numerical results agree well with the experimental ones. The CFD code ANSYS CFX, the k, e and the RNGk-e models of turbulence have been adopted for the resolutions. From the simulation results, the turbulent Schmidt number is a range of 0.1 to 1.3 that has some effect on the prediction of pollutant dispersion in the street canyons. In the case of a flat roof canyon configuration (case: runa000), appropriate turbulent Schmidt number of 0.6 is estimated using the k-epsilon model and of 0.5 using the RNG k-e model

The separation wall effect of a volute twin entry cross section area on the mixed inflow turbine performance

The pulse turbocharging system is used in many diesel engines and it is fortunate that nozzleless mixed turbines allow unsteady flow with less performance losses. It operates with a double or sometimes triple-entry casing creating different flow regimes in each sector. A nozzleless casing is used. The division of the cross section area takes the form of a solid wall in the radial plane. When the flow rate through one or the other volute inlet drops to zero, some reverse flow is observed from the other inlet. This situation suffers undesirable effects, diminishing the benefits of the divided volute casing types. A numerical investigation on the effect of the length of the dividing wall in the radial plane is performed using the ANSYS code. This possibility is explored and the results show that extending the wall to a limiting length enhances the flow behavior with better performance

Computational aerodynamic performance of mixed-flow turbine blade design

The performance of two mixed flow turbocharger turbine rotors is numerically investigated. Significantly, the two rotors differ mainly in their inlet angle geometry, one has a constant blade angle (rotor A) and the other has a nominal constant incidence angle (rotor B). Since experimental data alone are not sufficient for understanding the detailed flow field within the turbocharger turbine stage, a complete 3-D Computational Fluid Dynamics model is developed using commercial software Ansys CFX. The model is validated against experimental data for all steady conditions. This study presents a numerical performance prediction of two mixed flow turbine rotors for a wide range of rotational speeds and pressure ratios. The influence of inlet blade angle on the turbine performances is also investigated

TELEVISION, INTEGRATION ET CHANGEMENT SOCIOCULTUREL EN ALGERIE (PROBLEMATIQUE DES IMPLICATIONS SOCIOCULTURELLES ET IDEOLOGIEQUES DU PETIT ECRAN A L'AUNE DE SON INSTRUMENTALISATION PAR LE POLITIQUE)

PARIS-CUJAS-BU Droit (751052119) / SudocSudocFranceF