Search results for "RISA"
showing 10 items of 788 documents
Residual strain effects on the two-dimensional electron gas concentration of AlGaN/GaN heterostructures
2001
Ga-face AlGaN/GaN heterostructures with different sheet carrier concentrations have been studied by photoluminescence and Raman spectroscopy. Compared to bulk GaN, an energy shift of the excitonic emission lines towards higher energies was observed, indicating the presence of residual compressive strain in the GaN layer. This strain was confirmed by the shift of the E2 Raman line, from which biaxial compressive stresses ranging between 0.34 and 1.7 GPa were deduced. The spontaneous and piezoelectric polarizations for each layer of the heterostructures have been also calculated. The analysis of these quantities clarified the influence of the residual stress on the sheet electron concentratio…
Marchés du travail et disparités régionales en Pologne
2001
This article evaluates empirically the effect o f market introduction on the level o f regional inequalities and on the polarisation o f economic activities in Poland. We note an increase o f the disparities between regions over the relevant period. The re-polarisation process cannot been explained by a spatial re-allocation of labour force but rather results o f the differentiation of sectoral restructuring between regions the regional diversity o f sectoral adaptation. The search for agglomeration economies explains the spatial concentration o f services and o f added value in the regions where the biggest cities are located. A cumulative process o f agglomeration is observed. Therefore, …
Les mouvements de capitaux en union économique et monétaire : approches historiques et théoriques
2019
The liberalization of international capital flows seems linked to the increase and worsening of financial crisis. Since the financial crisis in 2007-2008, the ideological dimension of “happy globalization” has brought to light and given new strength to dissentient voices that could not be heard before. This thesis tries to evaluate the importance of capital flows on the stability of à financial system. Its purpose is to compare different financial systems and levels of financial liberalization, using the Economic and Monetary Union as an example because it combined full liberalization of the capital market within the zone a well as in relations with the outside. We have considered the need …
Long-term properties and end-of-life of polymers from renewable resources
2017
[EN] The long-term properties and end-of-life of polymers are not antagonist issues. They actually are inherently linked by the duality between durability and degradation. The control of the service-todisposal pathway at useful performance, along with low-impact disposal represents an added-value. Therefore, the routes of design, production, and discarding of bio-based polymers must be carefully strategized. In this sense, the combination of proper valorisation techniques, i.e. material, energetic and/ or biological at the most appropriate stage should be targeted. Thus, the consideration of the end-of-life of a material for a specific application, instead of the end-of-life of a material s…
Comparative study of the effectiveness of educational policies of inclusion in France and sub-Saharan Africa: a literature review
2013
Recommended by international bodies (UNESCO, 2006; 2008), inclusive education is based on the principle of equal opportunity. It aims to promote inclusion in the broad sense of the term by addressing specific audiences excluded or marginalized from educational systems. In recent years, regulatory frameworks have been defined for the education of certain categories excluded from educational systems including children with disabilities. Educational policies concerned with taking into account the needs of this group are also implemented. Do these policies promote effective integration of students with disabilities? To what extent can these policies be considered as effective? This paper presen…
The effects of armed conflict on schooling in Sub-Saharan Africa
2012
In the past decades, most of the countries in sub-Saharan Africa have been affected by armed conflicts. By means of a time-series cross-sectional (TSCS) database, we attempt to measure the impact of war on a sample of 43 countries in Africa from 1950 to 2010. These conflicts, and especially civil wars, are shown to have a strong negative effect on the educational performances of the countries studied. The rate of children not attending school, as well as secondary school enrollment rates, seems particularly sensitive to periods of conflict. It also appears that government expenditures in social sectors including education are a positive factor in increasing school enrollment. In contrast, m…
L'intelligence de l'enfant : l'empreinte du social
2007
07069; L'intelligence en général, l'intelligence de l'enfant en particulier, sont des questions vives, éternellement en débat. Est-il légitime d'évaluer l'intelligence par un chiffre de QI ? L'intelligence est-elle innée ou acquise ? Quel est le rôle de la famille, de l'école, de la société et de la culture dans la genèse de l'intelligence ? Quels enjeux autour de l'inégalité des capacités intellectuelles? Cet ouvrage fait suite à un premier volume qui présentait les nouvelles avancées de la psychologie cognitive. Il réunit un large éventail de travaux qui analysent le rôle de l'environnement dans la définition et le développement de l'intelligence ; ils pointent aussi les multiples enjeux,…
Suitability of blends from virgin and reprocessed polylactide: performance and energy valorization kinetics
2018
[EN] A blending strategy of virgin and reprocessed polylactide may be postulated as an alternative to reduce the material cost at industrial level, and as a valorisation route to plastic waste management of production scraps. The performance of blends prepared from virgin polylactide and polylactide mechanically reprocessed up to two cycles (PLA-V/R) was assessed in terms of thermo-oxidative stability, morphology, viscoelasticity and thermal kinetics for energetic valorisation. PLA-V/R blends showed appropriate thermo-oxidative stability. The amorphous nature of polylactide was preserved after blending. The viscoelastic properties showed an increment of the mechanical blend effectiveness, w…
On-body to on-body channel characterization
2011
Interest in on-body communication channels is growing as the use of wireless devices increases in medical, consumer and military sensor applications. This paper presents an experimental investigation and analysis of the narrowband on-body propagation channel. This analysis considers each of the factors affecting the channel during a range of stationary and motion activities in different environments with actual wireless mote devices on the body. Use of such motes allows greater freedom in the subject's movements and the inclusion of real-world indoor and outdoor environments in a test sequence. This paper identifies and analyses the effect of the different components of the signal propagati…
New Solution of Classical Hydraulic Jump
2009
This technical note, applying dimensional analysis and incomplete self-similarity, proposes a new functional relationship for the sequent depth ratio for hydraulic jumps over both smooth and rough horizontal beds. For the smooth bed condition, experimental measurements in the literature were used to calibrate the new relationship. For the rough bed condition the data of a previous investigation were used with new measurements carried out in a rectangular horizontal flume having a gravel bed. Finally, a generalized solution of the sequent depth ratio is proposed.