Search results for "method"

Impact of cyclic mechanical stress on the electrical contact resistance between gas diffusion layer and bipolar plates in Polymer Electrolyte Membran…

2018

WHEC 2018, 22nd edition of the WORLD HYDROGEN ENERGY CONFERENCE, Rio de Janeiro, BRESIL, 17-/06/2018 - 22/06/2018; and collisions) and the mechanical clamping stress applied during the stack assembly. The internal stresses come from the shrinking and the swelling of the membrane caused by water content and the difference between the thermal expansion coefficients of the cell components. These mechanical stresses have an impact on the global fuel cell's performance and one of the most sensitive cell's components to this pressure is the Gas Diffusion Layer (GDL). This layer, assembled with the membrane electrode assembly, provides the reactant gases, evacuates the produced heat and …

Determination of the effective permittivity of dielectric mixtures with the transmission line matrix methodDetermination of the effective permittivit…

2007

In this article, the effective permittivity of two-phase dielectric mixtures is calculated by applying the transmission line matrix (TLM) method. Two slightly different TLM algorithms are considered: a hybrid approach, which combines the TLM method with a subgriding technique based on dual capacitor circuits, to allow a refined description of the material, and a standard or pure TLM approach, which uses a mesh size smaller than the typical dimension of insertions in order to appropriately describe details of the geometry. A study of the statistical distribution of permittivity for insertions in random positions is also presented, showing that the effective permittivity of the mixture tends …

Evaluation of the impact of different odour notes on typicality of caramel aroma by recombination studies

2013

Poster (1 page); International audience; Aroma is one of the main factors that contribute to the consumer acceptability of a food product. Gas Chromatography/Olfactometry (GC/O) followed by accurate quantitation and recombination studies are usually carried out to evaluate key aroma compounds. The aim of this study is to develop a new approach taking into account odor qualities and to evaluate their impact on the typicality of caramel aroma. First, 58 aroma compounds, previously identified by GC/O analyses, were sorted into 8 odorant categories: animal, caramel, sour, vegetal, roasted, floral, fruity and nutty according to GC/O descriptors. For each category, a blend of compounds was prepar…

Structure and determinants of production in Textile-Clothing-Leather-Skins (TCLS) craft industry in Benin: a study based on investigations of the val…

2014

Lieu et date de la conférence modifiées. Prétoria 31Juillet au 2 Août 2014 (Au lieu de Kigali -Rwanda); International audience; Sustainable economic growth in Benin requires a better understand of the informalsector, which contributes to two-thirds of GDP. Particularly, craft industry and TCLSsubsector is one of informal activity sector to be handled. The objectives of this work wereto identify the structure and factors that determine the production in TCLS craft industry.This study was based on a survey carried out in February 2011 on value creationdata in craft industry of TCLS in Benin. Lack of data induced by informal activities wascircumvented using an imputation method. A Multiple Cor…

Initial strain effects in multilayer composite laminates

2001

A boundary integral formulation for the analysis of stress fields induced in composite laminates by initial strains, such as may be due to temperature changes and moisture absorption is presented. The study is formulated on the basis of the theory of generalized orthotropic thermo-elasticity and the governing integral equations are directly deduced through the generalized reciprocity theorem. A suitable expression of the problem fundamental solutions is given for use in computations. The resulting linear system of algebraic equations is obtained by the boundary element method and stress interlaminar distributions in the boundary-layer are calculated by using a boundary only discretization. …

COMPARISON OF CPML IMPLEMENTATIONS FOR THE GPU-ACCELERATED FDTD SOLVER

2011

Three distinctively difierent implementations of convolu- tional perfectly matched layer for the FDTD method on CUDA enabled graphics processing units are presented. All implementations store ad- ditional variables only inside the convolutional perfectly matched lay- ers, and the computational speeds scale according to the thickness of these layers. The merits of the difierent approaches are discussed, and a comparison of computational performance is made using complex real-life benchmarks.

The rational use of albumin in patients with cirrhosis and ascites

2004

Abstract Background. Ascites is one of the most frequent severe complications in patients with liver cirrhosis. The treatment of this chronic disease usually requires the prolonged use of albumin, frequently continued even after patients’ discharge from the hospital. Aims. Aim of the study was to define a consensus among Italian physicians with regard to the use of albumin in patients with decompensated cirrhosis and ascites. Methods. The study adopted the Delphi technique to conduct the consensus activities. All controversial issues related to the use of albumin were identified by the experts’ board and proposed to the 68 participating hepatology centres through two subsequent questionnair…

2015

Songs in passerine birds are important for territory defense and mating. Speciation rates in oscine passerines are so high, due to cultural evolution, that this bird lineage makes up half of the extant bird species. Leaf warblers are a speciose Old-World passerine family of limited morphological differentiation, so that songs are even more important for species delimitation. We took 16 sonographic traits from song recordings of 80 leaf warbler taxa and correlated them with 15 potentially explanatory variables, pairwise, and in linear models. Based on a well-resolved molecular phylogeny of the same taxa, all pairwise correlations were corrected for relatedness with phylogenetically independe…

Monte Carlo simulation of many-arm star polymers in two-dimensional good solvents in the bulk and at a surface

1991

A Monte Carlo technique is proposed for the simulation of statistical properties of many-arm star polymers on lattices. In this vectorizing algorithm, the length of each arml is increased by one, step by step, from a starting configuration withl=1 orl=2 which is generated directly. This procedure is carried out for a large sample (e.g., 100,000 configurations). As an application, we have studied self-avoiding stars on the square lattice with arm lengths up tol max=125 and up tof=20 arms, both in the bulk and in the geometry where the center of the star is adsorbed on a repulsive surface. The total number of configurations, which behaves asN∼l γ G–1μ fl , whereμ=2.6386 is the usual effective…

Neural Networks in ECG Classification

2011

In this chapter, we review the vast field of application of artificial neural networks in cardiac pathology discrimination based on electrocardiographic signals. We discuss advantages and drawbacks of neural and adaptive systems in cardiovascular medicine and catch a glimpse of forthcoming developments in machine learning models for the real clinical environment. Some problems are identified in the learning tasks of beat detection, feature selection/extraction, and classification, and some proposals and suggestions are given to alleviate the problems of interpretability, overfitting, and adaptation. These have become important problems in recent years and will surely constitute the basis of…