UVCVD silicon nitride passivation and ARC layers for multicrystalline solar cells

This work intends to investigate the effectiveness of silicon nitride layers (SiN_x : H) deposited by photochemical vapor deposition (UVCVD) for antireflection and passivation purposes when applied to electromagnetically casted silicon solar cells (EMC). Effective reflectivity of 10.8% is achieved, as well as 66% increase of minority carrier lifetime.     

New Challenges in Critical Infrastructures: A US Perspective

The emergence of a larger spectrum of threats – terrorism, sabotage, local conflicts, political unrest, and natural disasters – combined with the growing globalisation of economic activities, makes networks highly vulnerable. Rethinking national vulnerabilities requires the creation and the improvement of long‐term public‐private partnerships. This article discusses the US Presidential initiative launched in 1996 –the first initiative world wide to put these issues on the top‐level agenda– as well as the national structure of developed partnerships. It might constitute a starting point for other countries to develop their own national strategy, adapting it of course to their own national particularities. Terrorist attacks in 2001 show, however, that such an initiative is nothing but a first step in a general process to build preparedness nation wide; America still remains highly vulnerable. I conclude with a few myths that must be confronted to deal more efficiently with these new large‐scale risks at an international level.     

Modelling with stakeholders to integrate biodiversity into land-use planning – Lessons learned in Réunion Island (Western Indian Ocean)

This paper considers participatory modelling to integrate biodiversity conservation into land use planning and to facilitate the incorporation of ecological knowledge into public decision making for spatial planning. Réunion Island has experienced rapid urban and agricultural expansion, which threaten its unique biodiversity. In this context, we designed three participatory modelling sequences, involving overall 24 multidisciplinary researchers and stakeholders. The sequences aimed: (1) to map land-use and biodiversity, (2) to develop a conservation plan following systematic conservation planning principles using a spatial optimization tool (MARXAN) and (3) to simulate coupled land-use/conservation scenarios using a multi-agent system (MAS). The conservation plan confirms that priority areas for biodiversity protection are located on the coast where rapid land-use changes occur. Nevertheless, stakeholders from the urban and agricultural sector did not participate to this sequence. Indeed, conservation planning tools are useful to locate conservation priorities but they have to be designed with stakeholders to be accepted as negotiation tool. Besides, the researchers engaged in this second sequence were perceived as conservation stakeholders rather than holders of scientific knowledge. In the third sequence, the researchers involved adopted the stance of facilitating the elicitation of each stake and gathered trust from stakeholders. Overall, we conclude that the participatory development of land-use simulation models should be promoted to explore alternative scenarios for biodiversity conservation with stakeholders. In a situation of land-use conflict, a gradual and sequential participatory modelling approach should be implemented to fit into public decision-making processes.     

MBCP® biphasic calcium phosphate granules and tissucol® fibrin sealant in rabbit femoral defects: The effect of fibrin on bone ingrowth

An ageing population implies an increase in bone and dental diseases, which are in turn a source of numerous handicaps. These pathologies are an expensive burden for the European health system. As no specific bioactive materials are efficient enough to cope with this burden, we have to develop an injectable, mouldable, self-hardening bone substitute to support bone tissue reconstruction and augmentation.New, highly bioactive and suitable biomaterials have been developed to replace bone grafts in orthopedic revision and maxillofacial surgery for bone augmentation. These mouldable, self-hardening materials are based on the association of MBCP® Biphasic Calcium Phosphate Granules and Tissucol® Fibrin Sealant. The in vivo evaluation of ingrowth in relation to the composite was made in an experiment on rabbits. The results indicate that in the presence of fibrin sealant, newly-formed bone developed at a small distance from the surface of the calcium phosphate ceramic. Two different bone apposition processes were identified. Without the fibrin component (MBCP group), bone rested directly on the surface of the granules. This observation is commonly described as osteoconduction in calcium phosphate materials. On the contrary, the presence of the fibrinogen component seemed to modify this standard osteoconduction phenomenon: the newly-formed bone essentially grew at a distance from the surface of the granules, on the fibrillar network, and could be considered as an inductive phenomenon for osteogenic cell differentiation from mesenchymal stem cells.