Magnetic fluctuations in frustrated Laves hydrides R(Mn_{1-x}Al_{x})_{2}H_{y}

By neutron scattering, we have studied the spin correlations and spin fluctuations in frustrated Laves hydrides, where magnetic disorder sets in the topologically frustrated Mn lattice. Below the transition towards short range magnetic order, static spin clusters coexist with fluctuating and alsmost uncorrelated spins. The magnetic response shows a complexe lineshape, connected with the presence of the magnetic inhomogeneities. Its analysis shows the existence of two different processes, relaxation and local excitations, for the spin fluctuations below the transition. The paramagnetic fluctuations are discussed in comparison with classical spin glasses, cluster glasses, and non Fermi liquid itinerant magnets

Importance économique du Port Autonome de Liège: rapport 2003

The Port Autonome de Liège, with its 26 kilometres of berths and several multimodal platforms, plays an important role in the Walloon and Belgian economy. This update paper gives an extensive overview of the economic importance and the latest developments of the Port Autonome de Liège, through revised results for the period 1997 - 2003. Focusing on the three major variables of value added, employment and investment, it also provides some information about the financial situation of a few vital sectors. An indication concerning the financial health of the companies studied is also provided, using the National Bank's bankruptcy prediction model. In addition, it includes figures of several cargo traffics and draws a picture of social developments in the Port Autonome de Liège. Annual accounts data from the Central Balance Sheet Office were used for the calculation of direct effects, the study of financial ratios and the analysis of the social balance sheet. The indirect effects of these port activities are estimated in terms of value added (VA) and employment, on the basis of data from the National Accounts Institute. In the Liège harbour's network, direct VA came to 1 billion euro and total VA - the sum of direct and indirect VA - to 2 billion euro in 2003. In the same year direct and total employment respectively attained 12,400 and 28,500 fulltime equivalents, while investment directly linked with the port fell to 121 million euro. The position of the Port Autonome de Liège as the second largest inland port in Europe is threatened by the planned closure of the Cockerill Sambre's blast furnaces. This will take place gradually but will be completed by 2009. 2,700 direct and 4,500 indirect jobs are concerned, as well as 8 million tonnes of transhipment. However new spaces will be opened up, which means that new businesses will be created in the port area. New development sites are under construction and will soon be operative. An overall restructuring of the Liège harbour's network is under way and constitutes the main challenge for the Port Autonome de Liège's authorities in the next five years. In spite of this climate of uncertainty, the Port Autonome de Liège is striving to establish itself as a major logistic centre in the region, able to add value to the goods passing through it, in order to withstand the climate of increasing regional and international competition.branch survey, maritime cluster, subcontracting, indirect effects, transport intermodality, public investments.

Importance économique du Port Autonome de Liège: rapport 2002

This paper provides an extensive overview of the economic importance and development of the Port Autonome de Liège, over the period 1997 - 2002. Focusing on the three major variables of value added, salaried employment and investment, it also provides information about the financial situation of some vital segments in this inland port. In addition, it includes figures with respect to the ongoing growth of several cargo traffic segments and attempts to establish a link between these and the progress of the production in the industries at stake. The breakthrough of this research - compared to its first edition issued last year - consists of evaluating the indirect effects of the sectors in question in terms of value added and employment. A few refinements have also been made, such as the routine geographical and functional selection of companies according to the cluster they belong to (NACE-Bel code approach), the limitation of administrative work incurred, the review of the company-size analysis, etc. Annual reports data from the Central Balance Sheet have been computed for the calculation of direct effects, the study of financial ratios and the analysis of the social balance sheet. For the estimation of indirect effects, Supply and Use Tables from the National Accounts Institute have been resorted to. The developments in inland ports are numerous nowadays, as a parallel to the ever congesting road networks and the growing maritime traffic (e.g. increase in containerized shipments). The Port Autonome de Liège is the second largest inland port in Europe and therefore plays an important role in the development of inland waterways and of their traffic. Moreover, as it is the case for the maritime ports, the increase in scale and specialization of the vessels inevitably impacts the operation of this port. Production, trade and transport are no longer considered as individual, isolated activities, but are integrated within a single system. Therefore, ports have to evolve from mere centres of transport (discharging and loading of vessels) to logistic centres. The Port Autonome de Liège is a very good example of this evolution as it offers high-quality connections with the railways, motorways and the Liège airport. Intermodality is a great asset for the Port Autonome de Liège and is the spearhead of its future.branch survey, maritime cluster, subcontracting, indirect effects, transport intermodality, public investments.

Open problems in pluripotential theory

We propose a list of open problems in pluripotential theory partially motivated by their applications to complex differential geometry. The list includes both local questions as well as issues related to the compact complex manifold setting.Comment: 27 page

Time Segmentation Approach Allowing QoS and Energy Saving for Wireless Sensor Networks

Wireless sensor networks are conceived to monitor a certain application or physical phenomena and are supposed to function for several years without any human intervention for maintenance. Thus, the main issue in sensor networks is often to extend the lifetime of the network by reducing energy consumption. On the other hand, some applications have high priority traffic that needs to be transferred within a bounded end-to-end delay while maintaining an energy efficient behavior. We propose MaCARI, a time segmentation protocol that saves energy, improves the overall performance of the network and enables quality of service in terms of guaranteed access to the medium and end-to-end delays. This time segmentation is achieved by synchronizing the activity of nodes using a tree-based beacon propagation and allocating activity periods for each cluster of nodes. The tree-based topology is inspired from the cluster-tree proposed by the ZigBee standard. The efficiency of our protocol is proven analytically, by simulation and through real testbed measurements

Comparison of bacterial communities of tilapia fish from Cameroon and Vietnam using PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis)

Fishes in general and tilapia in particular are traded all over the world. However, it is difficult to find out their exact geographical location. One of the techniques used in the traceability of fish and its byproducts consist in analysing in a global way the whole viable and non viable bacterial communities. For this purpose, the molecular technique employing the bacterial 16S DNA banding profiles generated by PCR-DGGE (polymerase chain reaction-Denaturing gradient gel electrophoresis) was used to evaluate the differences between the bacterial profiles of fishes from Vietnam (An Giang, south province) and those of Cameroon (Yagoua, Maga, Lagdo). The different PCR-DGGE 16S rDNA banding profiles obtained were analysed and results showed that there were specific bands for each geographical location though some bands common to Cameroon and Vietnam were observed. This method could be used as a rapid analytical traceability tool for fish products and could be considered as a provider of a unique biological bar code. (Résumé d'auteur

Surface properties at the Kosterlitz-Thouless transition

Monte Carlo simulations of the two-dimensional XY model are performed in a square geometry with free and mixed fixed-free boundary conditions. Using a Schwarz-Christoffel conformal mapping, we deduce the exponent eta of the order parameter correlation function and its surface equivalent eta_parallel at the Kosterlitz-Thouless transition temperature. The well known value eta(T_{KT}) = 1/4 is easily recovered even with systems of relatively small sizes, since the shape effects are encoded in the conformal mapping. The exponent associated to the surface correlations is similarly obtained eta_1(T_{KT}) ~= 0.54.Comment: LaTeX file, 7 pages, 3 eps figure