Development of an Analytic Nodal Diffusion Solver in Multigroups for 3D Reactor Cores with Rectangular or Hexagonal Assemblies.

More accurate modelling of physical phenomena involved in present and future nuclear reactors requires a multi-scale and multi-physics approach. This challenge can be accomplished by the coupling of best-estimate core-physics, thermal-hydraulics and multi-physics solvers. In order to make viable that coupling, the current trends in reactor simulations are along the development of a new generation of tools based on user-friendly, modular, easily linkable, faster and more accurate codes to be integrated in common platforms. These premises are in the origin of the NURESIM Integrated Project within the 6th European Framework Program, which is envisaged to provide the initial step towards a Common European Standard Software Platform for nuclear reactors simulations. In the frame of this project and to reach the above-mentioned goals, a 3-D multigroup nodal solver for neutron diffusion calculations called ANDES (Analytic Nodal Diffusion Equation Solver) has been developed and tested in-depth in this Thesis. ANDES solves the steady-state and time-dependent neutron diffusion equation in threedimensions and any number of energy groups, utilizing the Analytic Coarse-Mesh Finite-Difference (ACMFD) scheme to yield the nodal coupling equations. It can be applied to both Cartesian and triangular-Z geometries, so that simulations of LWR as well as VVER, HTR and fast reactors can be performed. The solver has been implemented in a fully encapsulated way, enabling it as a module to be readily integrated in other codes and platforms. In fact, it can be used either as a stand-alone nodal code or as a solver to accelerate the convergence of whole core pin-by-pin code systems. Verification of performance has shown that ANDES is a code with high order definition for whole core realistic nodal simulations. In this paper, the methodology developed and involved in ANDES is presented

Impacto de las etiquetas em La interpretación de La escala de Likert

En este trabajo se comparan las distribuciones de las respuestas dadas a un cuestionario formulado en dos versiones, una con etiquetas representando el grado de acuerdo, frente a otra con etiquetas expresando la frecuencia de realización de una acción. Se examina la relación entre la percepción de cada etiqueta lingüística y las etiquetas frecuentistas mediante números borrosos. Se analiza la equivalencia entre ambos métodos, estudiando en detalle la equidistancia en la percepción de las etiquetas extremas. Se evalúan además las diferencias en función de la importancia del tema sobre el que se interroga

Nanosistemas quitosano/albúmina dirigidos a receptores de folato para la vehiculización de la doxorrubicina en la terapia del cáncer

A pesar de los numerosos avances que se ha conseguido en el diagnóstico del cáncer, así como en el tratamiento de la patología, todavía son muchas las mejoras que se tratan de conseguir para poder ponerle freno al avance de la enfermedad. Actualmente, una de las principales líneas de tratamiento es la quimioterapia, la cual ha demostrado su eficacia, pero su uso está limitado debido a los numerosos efectos adversos que derivan de él. Un ejemplo de estos fármacos antineoplásicos es la doxorrubicina, perteneciente a la familia de las antraciclinas, es un fármaco de amplio espectro empleado en numerosos tipos de cáncer. Sin embargo, presenta importantes efectos secundarios derivados de su uso tales como la cardiotoxicidad. Por otro lado, el auge de la nanotecnología y, más concretamente, de la nanomedicina, ha hecho posible el desarrollo de nuevos sistemas nanométricos de liberación controlada, capaces de transportar fármacos en su interior, aumentando su biodisponibilidad y disminuyendo los periodos de toxicidad e ineficacia propios de los tratamientos convencionales. La eficacia de la quimioterapia, unida a los efectos adversos de la misma, han hecho que los antineoplásicos sean buenos candidatos para ser encapsulados en el interior de nanosistemas de liberación controlada. Además, ciertas características propias de los tumores sólidos tales como el efecto de “Permeabilidad y Retención Aumentadas” (EPR), el microambiente ácido de las células tumorales o la sobreexpresión de ciertos receptores específicos de membrana, han hecho que estos sistemas puedan dirigirse de manera específica al tumor, aumentando su permanencia en el mismo y afectando en menor medida a las células sanas. Objetivos: Por todo lo expuesto anteriormente, el objetivo principal del presente trabajo se basa en la síntesis de nanosistemas basados en polímeros naturales (quitosano y albúmina) la vehiculización del fármaco antineoplásico doxorrubicina en la terapia del cáncer..

Valoración del daño corporal en pie y tobillo: aportaciones desde el ámbito del podólogo

En la Valoración del Daño Corporal se utilizan baremos ya que la cuantificación es primordial dentro de la labor pericial médica. Estos baremos en la mayoría de los casos no son de obligado cumplimiento y el hecho de que existan distintos baremos produce una falta de uniformidad. Revisados los baremos actuales en relación a la valoración del daño en tobillo y pie obtenemos las siguientes conclusiones: Cuando los baremos valoran los grados de limitación articular es preciso que se especifique cómo se realiza la medición. Sería necesario homogeneizar los criterios para reducir la variabilidad interobservador y favorecen la reproductibilidad de las mediciones. Se otorga mucha importancia a las mediciones clínicas que son muy variables y poca a las valoraciones funcionales. Es preciso valorar la necesidad de utilizar elementos ortoprotésicos para mejorar la función.In the Evaluation of damage corporal scales are used since the quantification is essential inside the medical expert work. These scales in most cases are not of forced fulfillment and the fact that different scales exist it produces an absence of uniformity. Checked the current scales as regards the evaluation of the damage in ankle and foot we obtain the following conclusions: When the scales value the limitation grades articulating is necessary that is specified how the measurement is realized. It would be necessary to homogenize the criteria to reduce the changeability interobserver and they favor the reproduce of the measurements. A lot of importance is granted to the clinical measurements that they are very variable and small to the functional evaluations. It is necessary to value the need to use elements ortoprotesics to improve the function

Propuesta de una guia para la valoración del daño corporal en tobillo y pie

En los baremos de valoración del daño utilizados en España existen diversas deficiencias en la valoración del tobillo y del pie. Se presenta una propuesta de guía para la valoración del daño corporal del tobillo y del pie y que recoge los efectos de las lesiones en sus articulaciones. Se determina que es necesario valorar el aparato locomotor desde el punto de vista funcional, así como el calzado y el desgaste del mismo. Por tratarse el tobillo y el pie de estructuras de carga deberían recibir una mayor puntuación en los baremos como se propone en la guía.In the scales of evaluation of the damage used in Spain diverse shortcomings exist in the evaluation of the ankle and of the foot. A guide proposal appears for the evaluation of the bodily harm of the ankle and of the foot and who gathers the effects of the injuries in its joints. One determines that it is necessary to value the locomotive device from the functional point of view, as well as the footwear and the wear of the same one. For there talk each other the ankle and the foot of structures of load they should receive a major punctuation in the scales as he proposes in the guide

Eficacia de un programa de entrenamiento combinado cognitivo y físico en la disminución del riesgo de caídas y del miedo a caer en ancianos

Tesis de la Universidad Complutense de Madrid, Facultad de Medicina, Departamento de Medicina, leída el 18-03-2019Depto. de MedicinaFac. de MedicinaTRUEunpu

Management of post-transplant diabetes mellitus: an opportunity for novel therapeutics

Post-transplant diabetes mellitus (PTDM) is a common problem after kidney transplantation (KT), occurring in 50% of high-risk recipients. The clinical importance of PTDM lies in its impactas a significant risk factor for cardiovascular and chronic kidney disease (CKD) after solid organ transplantation. Kidney Disease: Improving Global Outcomes (KDIGO) has recently updated the treatment guidelines for diabetes management in CKD with emphasis on the newer antidiabetic agents such as dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists and sodium-glucose co-transporter 2 inhibitors as add-on therapy to metformin. Given all these new diabetes treatments and the updated KDIGO guidelines, it is necessary to evaluate and give guidance on their use for DM management in KT recipients. This review summarizes the scarce published literature about the use of these new agents in the KT field. In summary, it is absolutely necessary to generate evidence in order to be able to safely use these new treatments in the KT population to improve blood glucose control, but specially to evaluate their potential cardiovascular and renal benefits that would seem to be independent of blood glucose control in PTDM patients

Transient analysis in the 3D nodal kinetics and thermal-hydraulics ANDES/COBRA coupled system

Neutron kinetics has been implemented in the 3D nodal solver ANDES, which has been coupled to the core thermal-hydraulics (TH) code COBRA-III for core transient analysis. The purpose of this work is, first, to discuss and test the ability of the kinetics solver ANDES to model transients; and second, by means of a systematic analysis, including alternate kinetics schemes, time step size, nodal size, neutron energy groups and spectrum, to serve as a basis for the development of more accurate and efficient neutronics/thermal-hydraulics tools for general transient simulations. The PWR MOX/UO2 transient benchmark provided by the OECD/NEA and US NRC was selected for these goals. The obtained ANDES/COBRA-III results were consistent with other solutions to the benchmark; the differences in the TH feedback led to slight differences in the core power evolution, whereas very good agreements were found in the other requested parameters. The performed systematic analysis highlighted the optimum kinetics iterative scheme, and showed that neutronics spatial discretization effects have stronger influence than time discretization effects, in the semi-implicit scheme adopted, on the numerical solution. On the other hand, the number of energy groups has an important influence on the transient evolution, whereas the assumption of using the prompt neutron spectrum for delayed neutrons is acceptable as it leads to small relative errors

SURFER v2.0: a flexible and simple model linking anthropogenic CO2 emissions and solar radiation modification to ocean acidification and sea level rise

We present SURFER, a novel reduced model for estimating the impact of CO2 emissions and solar radiation modification options on sea level rise and ocean acidification over timescales of several thousands of years. SURFER has been designed for the analysis of CO2 emission and solar radiation modification policies, for supporting the computation of optimal (CO2 emission and solar radiation modification) policies and for the study of commitment and responsibility under uncertainty. The model is based on a combination of conservation laws for the masses of atmospheric and oceanic carbon and for the oceanic temperature anomalies, and of adhoc parameterisations for the different sea level rise contributors: ice sheets, glaciers and ocean thermal expansion. It consists of 9 loosely coupled ordinary differential equations, is understandable, fast and easy to modify and calibrate. It reproduces the results of more sophisticated, high-dimensional earth system models on timescales up to millennia