High resolution electron energy loss spectroscopy of manganese oxides: application to Mn3O4 nanoparticles

Manganese oxides particularly Mn3O4 Hausmannite are currently used in many industrial applications such as catalysis, magnetism, electrochemistry or air contamination. The downsizing of the particle size of such material permits an improvement of its intrinsic properties and a consequent increase in its performances compared to a classical micron-sized material. Here, we report a novel synthesis of hydrophilic nano-sized Mn3O4, a bivalent oxide, for which a precise characterization is necessary and for which the determination of the valency proves to be essential. X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and particularly High Resolution Electron Energy Loss Spectroscopy (HREELS) allow us to perform these measurements on the nanometer scale. Well crystallized 10–20 nm sized Mn3O4 particles with sphere-shaped morphology were thus successfully synthesized. Meticulous EELS investigations allowed the determination of a Mn3+/Mn2+ ratio of 1.5, i.e. slightly lower than the theoretical value of 2 for the bulk Hausmannite manganese oxide. This result emphasizes the presence of vacancies on the tetrahedral sites in the structure of the as-synthesized nanomaterial

Translating Principles Into Practice in Regulation Theory

Regulators must understand basic principles of regulation, to explain with credibility their decissions, to asess the universality of the proposals, to develop new solutions, etc. For the relevance of economic theory, economists must fight to include in their frameworks enough constraints, as regulators face in practice, including technology constraints, even informational constraints, bureaucratic and political ones. Debates on regulation are turning around the world more important, defining the discussion frontier about the role of government in the economy.regulation; economic theory; government in the economy

Environmental Protection, Producer Insolvency and Lender Liability

The present paper deals with some legal issues surrounding environmental protection, namely those issues concerning the liability of the different firms and individuals directly or indirectly involved in the generation of environment damaging accidents. We consider in particular the potential effects of extending a firm's liability in case of an environmental disaster to its lenders and financiers when the cost of this liability is too large in relation to the firm's assets. Such extended liability regimes exist or are considered in many countries. The most important case is the 1980/85 Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) in the USA that led to an extensive jurisprudence over the last fifteen years. Nous traitons ici du cadre légal de la responsabilité directe des entreprises lors de désastres environnementaux et de l'extension de cette responsabilité aux prêteurs en cas de faillite de l'entreprise. De tels régimes existent ou sont à l'étude dans plusieurs pays. Le cas le plus connu est le Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) de 1980/85 aux États-Unis et nous analysons les principaux cas de jurisprudence auxquels cette loi a donné lieu depuis 15 ans.Environment, Extended Lender Liability, CERCLA, Environnement, responsabilité, CERCLA

The Subsidiarity Bias in Regulation

We study the choice of the regulatory structure when a regulated firm engages in different activities for different countries. Under decentralization each activity is regulated independently and the contracts offered to the firm suffer from two oppos- ite distortions with respect to centralization: the competition between regulatory authorities forces them to offer too high-powered incentive contracts; however, be- cause the ownership structure of the firm is dispersed across the countries, each regulator does not fully internalize the effect of his regulation on the firm's rent and contracts tend to be too low-powered. When the activities of the firm are suf- ficiently substitutable we show that decentralization always leads to an inefficient drift of the regulatory contracts towards fixed-price contracts. Nonetheless, when regulators have private agendas and possess the discretion to distort their policy to gain the support of some interest groups, then decentralization of the regulat- ory powers may be preferred to centralization as competition between regulatory authorities eradicates their discretionary power.incentives, decentralization, regulation.

Telecommuications reform in Cote d'Ivoire

This paper analyzes C?e d'Ivoire's experience with telecommunications liberalization and privatization. C?e d'Ivoire privatized its incumbent operator in 1997, and granted the newly privatized firm seven years of fixed-line exclusivity while introducing"managed competition"in the cellular market and free competition in value-added services (VAS). By March 2001, three cellular operators and a number of VAS providers had entered the market. Reform has thus significantly changed the landscape of C?e d'Ivoire's telecommunications sector and has brought with it tremendous improvement in sector performance. Between 1997 and 2001, fixed-line telephone penetration grew from 1.03 to 1.80 per hundred people, while mobile penetration skyrocketed from 0.26 to 4.46. But it is still too early to assess the validity of granting exclusivity to the incumbent operator. While penetration increased, the operator did not meet objectives regarding rural telephony and service quality. Moreover, fixed-line penetration increased in areas where the operator faced competition from mobile providers.Payment Systems&Infrastructure,Telecommunications Infrastructure,Broadcast and Media,ICT Policy and Strategies,Economic Theory&Research,ICT Policy and Strategies,Telecommunications Infrastructure,Economic Theory&Research,Broadcast and Media,Rural Communications