On an upper bound for the arithmetic self-intersection number of the dualizing sheaf on arithmetic surfaces

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On the number of limit cycles bifurcating from a non-global degenerated center

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Endogenous population subgroups: the best population partition and optimal number of groups

The aim of this paper is to suggest a method to find endogenously the points that group the individuals of a given distribution in k clusters, where k is endogenously determined. These points are the cut-points. Thus, we need to determine a partition of the N individuals into a number k of groups, in such way that individuals in the same group are as alike as possible, but as distinct as possible from individuals in other groups. This method can be applied to endogenously identify k groups in income distributions: possible applications can be poverty

Lower bounds for the number of limit cycles of trigonometric Abel equations

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On the upper bound of the number of limit cycles obtained by the second order averaging method I

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On the upper bound of the number of limit cycles obtained by the second order averaging method II

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On the number of K3,3-minor-free and maximal K3,3-minor-free graphs

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Experimental investigation of transient natural convection cooling of high prandtl number fluid with variable viscosity

Report for the scientific sojourn at the James Cook University, Australia, between June to December 2007. Free convection in enclosed spaces is found widely in natural and industrial systems. It is a topic of primary interest because in many systems it provides the largest resistance to the heat transfer in comparison with other heat transfer modes. In such systems the convection is driven by a density gradient within the fluid, which, usually, is produced by a temperature difference between the fluid and surrounding walls. In the oil industry, the oil, which has High Prandtl, usually is stored and transported in large tanks at temperatures high enough to keep its viscosity and, thus the pumping requirements, to a reasonable level. A temperature difference between the fluid and the walls of the container may give rise to the unsteady buoyancy force and hence the unsteady natural convection. In the initial period of cooling the natural convection regime dominates over the conduction contribution. As the oil cools down it typically becomes more viscous and this increase of viscosity inhibits the convection. At this point the oil viscosity becomes very large and unloading of the tank becomes very difficult. For this reason it is of primary interest to be able to predict the cooling rate of the oil. The general objective of this work is to develop and validate a simulation tool able to predict the cooling rates of high Prandtl fluid considering the variable viscosity effects.

Computation of an integral basis of a quartic number field

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Computation of an integral basis of quartic number field

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On the number of higher order Delaunay triangulations

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A functional equation related to the product in a quadratic number field

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Avaluació del filtrat glomerular en candidats a donant renal viu

En una població de pacients candidats a ser donant renal viu, la determinació acurada i precisa de la de la taxa de filtrat glomerular (TFG) és important ja que d’ella en depen que s’accepti o rebutji un canditat a donant renal viu. En aquest estudi es compara la determinació de la TFG calculada segons el mètode isotòpic amb 51Cr-EDTA amb la TFG calculada amb mètodes estimatius basats en substàncies endògenes com la creatinina i la cistatina.

Cistatina C como nuevo marcador del Filtrado Glomerular en población seleccionada

Les fórmules que mesuren el filtrat glomerular basades en la creatinina sèrica son imprecises i infraestiman el FG en pacients ancians sense evidència d’ insuficiència renal. L’objectiu d’aquest treball es comparar les fórmules basades en creatinina amb la fórmula de Hoek basada en la cistatina C, molècula proposada com a nou marcador endogen d’insuficiència renal. S’estudiaren 40 individus amb una edat superior a 70 anys amb creatinina sèrica normal i sense evidència de malaltia renal, amb MDRD calculat & 60 ml/min, considerant el FG mesurat mitjançant TC 99m-DTPA com a prova gold estandad.