Nonextensive Interpretation Of Radiative Recombination In Electron Cooling

An interest for the low-energy range of the nonextensive distribution function arises from the study of radiative recombination in electron cooling devices in particle accelerators, whose experimentally measured reaction rates are much above the theoretical prediction. The use of generalized distributions, that differ from the Maxwellian in the low energy part (due to subdiffusion between electron and ion bunches), may account for the observed rate enhancement. In this work, we consider the isotropic distribution function and we propose a possible experiment for verifying the existence of a cut-off in the generalized momentum distribution, by measuring the spectrum of the X-rays emitted from radiative recombination reactions.Comment: 8 pages, 2 figures, Submitted for publication in the Proceedings of the 3rd International Conference NEXT-SigmaPhi, 2005, Cret

Reduction of Lie--Jordan algebras: Quantum

In this paper we present a theory of reduction of quantum systems in the presence of symmetries and constraints. The language used is that of Lie--Jordan Banach algebras, which are discussed in some detail together with spectrum properties and the space of states. The reduced Lie--Jordan Banach algebra is characterized together with the Dirac states on the physical algebra of observables

On dissipated energy density in compression for concrete

An experimental investigation on drilled cylindrical concrete specimens in compression over a large scale range (1:19) has been carried out to evaluate the variation of some mechanical parameters by varying specimen size. The peculiarity of the present investigation consists in exploring very small specimen dimensions. The experimental results show scale effects on dissipated energy density rather than on uniaxial compressive strength. A theoretical explanation for such a phenomenon, based on fractal hypothesis, is presented and a comparison between experimental and theoretical values is discussed. © 2006 Elsevier Ltd. All rights reserved

Quality interoperability within digital libraries: the DL.org perspective

Quality is the most dynamic aspect of DLs, and becomes even more complex with respect to interoperability. This paper formalizes the research motivations and hypotheses on quality interoperability conducted by the Quality Working Group within the EU-funded project DL.org (<a href="http://www.dlorg.eu">http://www.dlorg.eu/</a>). After providing a multi-level interoperability framework – adopted by DL.org - the authors illustrate key-research points and approaches on the way to the interoperability of DLs quality, grounding them in the DELOS Reference Model. By applying the DELOS Reference Model Quality Concept Map to their interoperability motivating scenario, the authors subsequently present the two main research outcomes of their investigation - the Quality Core Model and the Quality Interoperability Survey

Health monitoring for strongly non‐linear systems using the Ensemble Kalman filter

Many structural engineering problems of practical interest involve pronounced non-linear dynamics the governing laws of which are not always clearly understood. Standard identification and damage detection techniques have difficulties in these situations which feature significant modelling errors and strongly non-Gaussian signals. This paper presents a combination of the ensemble Kalman filter and non-parametric modelling techniques to tackle structural health monitoring for non-linear systems in a manner that can readily accommodate the presence of non-Gaussian noise. Both location and time of occurrence of damage are accurately detected in spite of measurement and modelling noise. A comparison between ensemble and extended Kalman filters is also presented, highlighting the benefits of the present approach. Copyright © 2005 John Wiley & Sons, Ltd

Reduced lysosomal acid lipase activity: A new marker of liver disease severity across the clinical continuum of non-alcoholic fatty liver disease?

Lysosomal acid lipase (LAL) plays a key role in intracellular lipid metabolism. Reduced LAL activity promotes increased multi-organ lysosomal cholesterol ester storage, as observed in two recessive autosomal genetic diseases, Wolman disease and Cholesterol ester storage disease. Severe liver steatosis and accelerated liver fibrosis are common features in patients with genetic LAL deficiency. By contrast, few reliable data are available on the modulation of LAL activity in vivo and on the epigenetic and metabolic factors capable of regulating its activity in subjects without homozygous mutations of the Lipase A gene. In the last few years, a less severe and non-genetic reduction of LAL activity was reported in children and adults with non-alcoholic fatty liver disease (NAFLD), suggesting a possible role of LAL reduction in the pathogenesis and progression of the disease. Patients with NAFLD show a significant, progressive reduction of LAL activity from simple steatosis to non-alcoholic steatohepatitis and cryptogenic cirrhosis. Among cirrhosis of different etiologies, those with cryptogenic cirrhosis show the most significant reductions of LAL activity. These findings suggest that the modulation of LAL activity may become a possible new therapeutic target for patients with more advanced forms of NAFLD. Moreover, the measurement of LAL activity may represent a possible new marker of disease severity in this clinical setting

Cuore-Fegato-Rene: quando l'unione non fa la forza

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