10 research outputs found
Robustness of the European power grids under intentional attack
The power grid defines one of the most important technological networks of
our times and sustains our complex society. It has evolved for more than a
century into an extremely huge and seemingly robust and well understood system.
But it becomes extremely fragile as well, when unexpected, usually minimal,
failures turn into unknown dynamical behaviours leading, for example, to sudden
and massive blackouts. Here we explore the fragility of the European power grid
under the effect of selective node removal. A mean field analysis of fragility
against attacks is presented together with the observed patterns. Deviations
from the theoretical conditions for network percolation (and fragmentation)
under attacks are analysed and correlated with non topological reliability
measures.Comment: 7 pages, 4 figure
Urinary thiodiacetic acid. A selective biomarker for the cytochrome P450-catalyzed oxidation of 1,2-dibromoethane in the rat. Drug Metab Dispos
ABSTRACT: 1,2-Dibromoethane (1,2-DBE) is a carcinogenic compound that is metabolized both by cytochrome P450 (P450) and glutathione Stransferase (GST) enzymes, and that has been used by us as a model compound to study interindividual variability in biotransformation reactions. In this study, the excretion of thiodiacetic acid (TDA) and S-(2-hydroxyethyl)-N-acetyl-l-cysteine (2-HEMA) were measured in the urine of rats dosed with 1,2-DBE, and experiments were performed to investigate to what extent P450 and GST enzymes contribute to the formation of TDA. To this end, CYP2E1, the main P450 isoenzyme catalyzing the oxidation of 1,2-DBE, was inhibited using disulfiram and diallylsulfide. Significant inhibition o
Presence of Li Clusters in Molten LiCl-Li
Molten mixtures of lithium chloride and metallic lithium are of significant interest in various metal oxide reduction processes. These solutions have been reported to exhibit seemingly anomalous physical characteristics that lack a comprehensive explanation. In the current work, the physical chemistry of molten solutions of lithium chloride and metallic lithium, with and without lithium oxide, was investigated using in situ Raman spectroscopy. The Raman spectra obtained from these solutions were in agreement with the previously reported spectrum of the lithium cluster, Li(8). This observation is indicative of a nanofluid type colloidal suspension of Li(8) in a molten salt matrix. It is suggested that the formation and suspension of lithium clusters in lithium chloride is the cause of various phenomena exhibited by these solutions that were previously unexplainable