Search results for "Carl"

Evaluating the material resource efficiency of secondary aluminium production: A Monte Carlo-based decision-support tool

2019

The contamination of aluminium streams during the different life cycle stages by alloy mixing and/or accumulation of foreign elements, in combination with the limited melt purification options during remelting, represents an important limiting factor in recycling. Consequently, in secondary aluminium production, primary aluminium is used to dilute the concentration of the residual elements, and alloying elements are added to adjust the composition to the target alloy specifications. However, adding elements, for which their refinement in a subsequent recycling step is problematic, results in permanent down-cycling or ‘quality losses’. Hence, it is crucial to more efficiently control the com…

Predictive Model Markup Language (PMML) Representation of Bayesian Networks: An Application in Manufacturing

2018

International audience; Bayesian networks (BNs) represent a promising approach for the aggregation of multiple uncertainty sources in manufacturing networks and other engineering systems for the purposes of uncertainty quantification, risk analysis, and quality control. A standardized representation for BN models will aid in their communication and exchange across the web. This article presents an extension to the predictive model markup language (PMML) standard for the representation of a BN, which may consist of discrete variables, continuous variables, or their combination. The PMML standard is based on extensible markup language (XML) and used for the representation of analytical models…

A simulated annealing-based approach for the joint optimization of production/inventory and preventive maintenance policies

2017

Even if more reliable than the past, the performance of modern manufacturing systems is still affected by machine’s deteriorations and breakdowns. As a consequence, adequate maintenance programs must be implemented to adequately satisfy demands during manufacturing stops due to unexpected failures or preventive maintenance (PM) actions. Despite production and maintenance are closely related issues, their joint optimization has become an important research topic just during the last decade. Therefore, the present paper proposes a model for the combined optimization of production/inventory control and PM policies with the aim of minimizing the total expected cost per unit time. The model is f…

Through-transmission laser welding of polymers – temperature field modeling and infrared investigation

2007

The purpose of the present study is to estimate the weldability of a polymeric material couple according to their thermal and optical properties. A first model based on Mie theory and Monte Carlo method describes the laser beam behavior in semi-transparent media and makes it possible to approximate the laser power distribution at the interface of the two materials. A second model based on finite element method permits the temperature field estimation into both parts to be welded. The results are validated by infrared thermography.

GOBERNANZA DEL AGUA Y TERRITORIOS HIDROSOCIALES: DEL ANÁLISIS INSTITUCIONAL A LA ECOLOGÍA POLÍTICA

2018

[ES] En las últimas décadas han surgido diversos enfoques para dar respuesta a los desafíos que plantea la gestión del agua. Este artículo presenta, de manera introductoria, las principales aproximaciones teóricas desde las cuales se está analizando en la actualidad el uso y la gobernanza del agua: las corrientes neoinstitucionalistas, la teoría de los recursos comunes y la perspectiva del empoderamiento que se relaciona con la ecología política. La descripción de estos enfoques sirve para contextualizar las distintas aportaciones que se presentan en este monográfico sobre el estudio de los territorios hidrosociales, cuyos principales resultados se exponen sucintamente.

Onset of cohesion in cement paste

2004

It is generally agreed that the cohesion of cement paste occurs through the formation of a network of nanoparticles of a calcium-silicate-hydrate ("C-S-H"). However, the mechanism by which these particles develop this cohesion has not been established. Here we propose a dielectric continuum model which includes all ionic interactions within a dispersion of C-S-H particles. It takes into account all co-ions and counterions explicitly (with pure Coulomb interactions between ions and between ions and the surfaces) and makes no further assumptions concerning their hydration or their interactions with the surface sites. At high surface charge densities, the model shows that the surface charge of…

Incorporaciones de obras de arte a las colecciones de la Real Academia de Bellas Artes de San Carlos, 2015-2016

2016

VV. AA. (Obra coordinada por Tito Llopis / VTiM) L' escultor Josep Ginés i Marín (1768-1823). A propòsit de "La matança dels innocents" : Catálogo de…

2020

2016

We determine knotting probabilities and typical sizes of knots in double-stranded DNA for chains of up to half a million base pairs with computer simulations of a coarse-grained bead-stick model: Single trefoil knots and composite knots which include at least one trefoil as a prime factor are shown to be common in DNA chains exceeding 250,000 base pairs, assuming physiologically relevant salt conditions. The analysis is motivated by the emergence of DNA nanopore sequencing technology, as knots are a potential cause of erroneous nucleotide reads in nanopore sequencing devices and may severely limit read lengths in the foreseeable future. Even though our coarse-grained model is only based on …

Intermittent targeted therapies and stochastic evolution in patients affected by chronic myeloid leukemia

2016

Front line therapy for the treatment of patients affected by chronic myeloid leukemia (CML) is based on the administration of tyrosine kinase inhibitors, namely imatinib or, more recently, axitinib. Although imatinib is highly effective and represents an example of a successful molecular targeted therapy, the appearance of resistance is observed in a proportion of patients, especially those in advanced stages. In this work, we investigate the appearance of resistance in patients affected by CML, by modeling the evolutionary dynamics of cancerous cell populations in a simulated patient treated by an intermittent targeted therapy. We simulate, with the Monte Carlo method, the stochastic evolu…