6 resultados para Cas contrastés

em Aston University Research Archive


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In a linguistic context where it seems the entire world is only interested in learning English, it is worth considering the idea of whether French still has a place in Mexico. In spite of the predominance of English, there is nevertheless a feeling that French remains alive in Mexico, and indeed in certain areas has retained its strength and appeal. This hypothesis was to put to the test by exploring the current linguistic environment prevalent in the state of Veracruz. An investigation in the form of questionnaires and interviews of all those connected to the teaching of French (including students, teachers and employees and directors of language schools) shows that the desire of the Mexican government of promoting English for everyone is not necessarily consistent with the desire and expectations of the general populace. This in turn suggest the need of adopting a policy that enables us not only to take into consideration what people seem to be telling us regarding the learning of foreign learning but also of what they are not telling us. If the teaching and learning of French as a foreign language remains strong in Veracruz, it is explained much more by the long and friendly relationship that people in the state have had with French people (and their culture) than it is by any instrumental needs of learning their language. This is seen in the fact that students here consistently describe their motivation for learning French from an emotional or affective standpoint rather than from professional one. It seems that the ties between the Mexican and French people remain solid. Another interesting characteristic of students of French in Veracruz is the positive attitude they seem to have regarding languages in general, which in turn enables them to take further advantage of the benefits made available from globalization. In reality, there exists no rivalry between French and English and therefore it is unnecessary to adopt measures that would address such struggle. It is however a matter of great urgency that authorities in the arenas of politics and academia take a closer look at the policies they design regarding the study of foreign languages in general, and that they consider, specifically, a wholly alternative to the one language model of teaching and learning of foreign language – in this case English-, a model that for all intents and purposes has failed. In the midst of a globalized world, and during this current period of increased linguistic activity, the aforementioned assertions serve not only to support my initial hypothesis, but also to help shake off the dust of some out-dated belief systems and lay down the framework for a new, better informed and well thought-out policy of foreign languages planning.

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The stability characteristics of an incompressible viscous pressure-driven flow of an electrically conducting fluid between two parallel boundaries in the presence of a transverse magnetic field are compared and contrasted with those of Plane Poiseuille flow (PPF). Assuming that the outer regions adjacent to the fluid layer are perfectly electrically insulating, the appropriate boundary conditions are applied. The eigenvalue problems are then solved numerically to obtain the critical Reynolds number Rec and the critical wave number ac in the limit of small Hartmann number (M) range to produce the curves of marginal stability. The non-linear two-dimensional travelling waves that bifurcate by way of a Hopf bifurcation from the neutral curves are approximated by a truncated Fourier series in the streamwise direction. Two and three dimensional secondary disturbances are applied to both the constant pressure and constant flux equilibrium solutions using Floquet theory as this is believed to be the generic mechanism of instability in shear flows. The change in shape of the undisturbed velocity profile caused by the magnetic field is found to be the dominant factor. Consequently the critical Reynolds number is found to increase rapidly with increasing M so the transverse magnetic field has a powerful stabilising effect on this type of flow.

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Magnetic nanoparticles (NPs) MnFe2O4 and Fe3O4 were stabilised by depositing an Al(OH)3 layer via a hydrolysis process. The particles displayed excellent colloidal stability in water and a high affinity to [18F]-fluoride and bisphosphonate groups. A high radiolabeling efficiency, 97% for 18F-fluoride and 100% for 64Cu-bisphosphonate conjugate, was achieved by simply incubating NPs with radioactivity solution at room temperature for 5min. The properties of particles were strongly dependant on the thickness and hardness of the Al(OH)3 layer which could in turn be controlled by the hydrolysis method. The application of these Al(OH)3 coated magnetic NPs in molecular imaging has been further explored. The results demonstrated that these NPs are potential candidates as dual modal probes for MR and PET. In vivo PET imaging showed a slow release of 18F from NPs, but no sign of efflux of 64Cu. © 2014 The Authors.