Correlations of structural, magnetic, and dielectric properties of undoped and doped CaCu3Ti4O12

The present work reports synthesis, as well as a detailed and careful characterization of structural, magnetic, and dielectric properties of differently tempered undoped and doped CaCu3Ti4O12 (CCTO) ceramics. For this purpose, neutron and x-ray powder diffraction, SQUID measurements, and dielectric spectroscopy have been performed. Mn-, Fe-, and Ni-doped CCTO ceramics were investigated in great detail to document the influence of low-level doping with 3d metals on the antiferromagnetic structure and dielectric properties. In the light of possible magnetoelectric coupling in these doped ceramics, the dielectric measurements were also carried out in external magnetic fields up to 7 T, showing a minor but significant dependence of the dielectric constant on the applied magnetic field. Undoped CCTO is well-known for its colossal dielectric constant in a broad frequency and temperature range. With the present extended characterization of doped as well as undoped CCTO, we want to address the question why doping with only 1% Mn or 0.5% Fe decreases the room-temperature dielectric constant of CCTO by a factor of ~100 with a concomitant reduction of the conductivity, whereas 0.5% Ni doping changes the dielectric properties only slightly. In addition, diffraction experiments and magnetic investigations were undertaken to check for possible correlations of the magnitude of the colossal dielectric constants with structural details or with magnetic properties like the magnetic ordering, the Curie-Weiss temperatures, or the paramagnetic moment. It is revealed, that while the magnetic ordering temperature and the effective moment of all investigated CCTO ceramics are rather similar, there is a dramatic influence of doping and tempering time on the Curie-Weiss constant.Comment: 10 pages, 11 figure

Search for excited leptons in Z0^0 decay

Due to the severity of system-wide power outages, though their probability of occurrence is slight, regulatory authorities require that a system restoration plan be drawn up and kept up to date at all times. The power outage that affected northeastern North America in 2003 proved the need for such a requirement. The particular structure of Hydro-Québec's power system requires the use of a highly specific system restoration procedure. The daily preparation of the system restoration plan is based on a strategy whose application requires that a restoration sequence be drawn up that uses available equipment, the electrical behavior of which has been validated using appropriate studies. Over the years, Hydro-Québec has accumulated a sizeable pool of knowledge that brings together all the solutions already studied. System restoration planners use their know-how to find the best solution, determine whether it is appropriate, and proceed to apply it. When required, new solutions must be developed. The new RECRÉ software program (French acronym for “Remise En Charge du Réseau” – System Restoration) has been implemented by Hydro-Québec in 2005. The aim of this knowledge management system is to have system restoration knowledge become a tangible, growth-oriented and enhanceable asset. The system is made up of two modules: the knowledge engineering module, whereby modeling can be done of the system restoration strategy and known solutions in a knowledge base, and the planning module, whereby system restoration plans can be drawn up based on the unavailability of power system equipment. The RECRÉ system can produce a validated and adequate plan in a few seconds along with all the documents required for its dissemination. The RECRÉ system can also analyze in a few minutes all of the situations that apply to scheduled outages for the weeks that follow or the upcoming year. This allows solution gaps to be identified in the knowledge base

A precise determination of the number of families with light neutrinos and of the Z boson partial widths

Title : The socialization at work in the federal universe, the determining element of the social regulation of the sports organization. Contribution to the social politics of the sport service of Nice city Abstract : This study postulates the existence of certain specific cultural determinism in the social regulation of the sports organization. It leans on a work of inquiry which concerns 148 agents of the municipal service of the sports of the Nice city. The investigation puts in evidence a causal report between the type of trajectory of professional insertion of the municipal agents and their level of support in the manager politics of the organization. The agents, whose bibliographic route contains a passage within the federal sports universe, the member more mainly in rules, procedures to be respected and verbal orders were promulgated by the management. This commitment seems inferred by the institutional logics at work in sporting clubs where from partially arise these professionals. This original and specific socialization, in the work within sports unions and centred on the values of an ideal sportsman, can consider as a sociological determiner in the management of the sports organization

Search for excited leptons in Z0^0 decay

Due to the severity of system-wide power outages, though their probability of occurrence is slight, regulatory authorities require that a system restoration plan be drawn up and kept up to date at all times. The power outage that affected northeastern North America in 2003 proved the need for such a requirement. The particular structure of Hydro-Québec's power system requires the use of a highly specific system restoration procedure. The daily preparation of the system restoration plan is based on a strategy whose application requires that a restoration sequence be drawn up that uses available equipment, the electrical behavior of which has been validated using appropriate studies. Over the years, Hydro-Québec has accumulated a sizeable pool of knowledge that brings together all the solutions already studied. System restoration planners use their know-how to find the best solution, determine whether it is appropriate, and proceed to apply it. When required, new solutions must be developed. The new RECRÉ software program (French acronym for “Remise En Charge du Réseau” – System Restoration) has been implemented by Hydro-Québec in 2005. The aim of this knowledge management system is to have system restoration knowledge become a tangible, growth-oriented and enhanceable asset. The system is made up of two modules: the knowledge engineering module, whereby modeling can be done of the system restoration strategy and known solutions in a knowledge base, and the planning module, whereby system restoration plans can be drawn up based on the unavailability of power system equipment. The RECRÉ system can produce a validated and adequate plan in a few seconds along with all the documents required for its dissemination. The RECRÉ system can also analyze in a few minutes all of the situations that apply to scheduled outages for the weeks that follow or the upcoming year. This allows solution gaps to be identified in the knowledge base