Influence des paramètres de formulation des pâtes ciments sur les aspects de parements

Les principaux paramètres influençant la variation de la couleur (luminance=L*) dans les surfaces des pâtes de ciments (parement) ont été identifiés, tel que la variation du rapport eau sur ciment (E/C) et la rugosité de surface. Dans la littérature, les auteurs ont des avis divergents à propos de l'influence du rapport E/C et de la rugosité de surface sur la luminance dans les matériaux cimentaires. Donc, nous avons réalisé des essais expérimentaux pour déterminer la relation qui existe entre la luminance de surface des pâtes et le rapport E/C, d'une part, et la relation entre la luminance et la rugosité, d'autre part. Les résultats sont ensuite utilisés pour réaliser des simulations numériques afin de déterminer l'impact de la rhéologie de pâtes de ciments frais sur l'état de surface final. En effet, nous avons constaté que la formulation est l'un des facteurs déterminant la rhéologie des pâtes permettant ainsi de prédire l'état de surface à l'état durci. Cet état de surface peut être mesuré en termes de luminance. Cet article est composé en 3 parties : Dans une première partie, nous allons identifier les principaux défauts de parements et étudier la rhéologie du béton frais. Dans la deuxième partie, nous allons présenter les résultats des essais expérimentaux réalisés pour déterminer la relation existante entre la luminance et la rugosité, pour ensuite étudier le comportement des pâtes en utilisant un rhéomètre afin de déterminer la viscosité et le seuil de cisaillement. Finalement, nous allons utiliser les données expérimentales obtenus pour réaliser les simulations numériques via le logiciel COMSOL multiphysics avec « Computational Fluid Dynamics » (CFD) en utilisant la loi de Bingham Papanastasiou pour étudier le comportement de l'écoulement de pâtes frais

Micro-dilatation theory application to the spongy bones: Theoretical aspects and numerical modeling

The micro-structural study of the porous materials is an essential issue in understanding the transfer phenomenon and chemical reactions impact on their global response. The spongy bone entails many complex phenomena, i.e. remodeling, fluid transfer and so on. The generalized continuum mechanics can be used to handle these requirement in an inherent manner. The geometrically-exact Cosserat theory has been applied to the human spongy bones in the previous studies \cite{Ramezani2012c}. This prepares a multi-scale modeling for the spongy bones. The use of the Cosserat theory does not provide the spatial porosity distribution and its impact on the re-modeling for the next studies. The micro-dilatation theory or so-called void elasticity can perfectly achieve this assignment. The micro-dilatation theory belongs to the generalized continuum theory either and it provides deep understanding about the spatial porosity variation under the mechanical actions as well as the chemically-driven reactions through the porous media. In the present study, the micro-dilatation theory is used to investigate the spongy bones and some fresh routes in the remodeling issue of the human bones are discussed

On the numerical modeling of carbonation phenomenon via multi-reactional kinetics and 3D-randomly distributed spherical grains

In the present contribution, the mathematical modeling and numerical solution of the carbonation phenomenon have been investigated for the porous cement mortars. To achieve this goal, the Papadakis analytical proposal has been fully investigated. The molar concentration variations of the hydrate (CSH and Ca(OH)2 ) and unhydrated products (C2S and C3S) have been analyzed during the carbonation. The numerical simulations have been firstly achieved on the 3D numerical mortar samples including the aggregates using the relevant granulometry, whose applications sustain more realistic outcomes. The solution has been done using the FEM for the non-linear transient system of PDEs. The numerical results have been compared to those done from the experiments using the pH detector and Differential Thermal Analysis (DTA). Some conclusions and outlooks pertaining to the carbonation modeling have been emphasized

Wave overtopping and overflow hazards: application on the Camargue sea-dike

Hydrodynamic

Random materials modeling: Statistical approach proposal for recycling materials

The current paper aims to promote the application of demolition waste of the Civil Engineering constructions. To achieve this assignment, two main physical properties, i.e. dry density and water absorption of the recycled aggregates have been chosen and studied at the first stage. The material moduli of the recycled materials, i.e. the Lamé's coefficients, lambda and mu strongly depend on the porosity. Moreover, the recycling materials should be considered as random materials. As a result, the statistical approach would be the most suitable way to handle and assess the level of certitude of the materials behavior as well as structures response

Diagnostic Efficacy of PET/CT Plus Brain MR Imaging for Detection of Extrathoracic Metastases in Patients with Lung Adenocarcinoma

We aimed to evaluate prospectively the efficacy of positron emission tomography (PET)/computed tomography (CT) plus brain magnetic resonance imaging (MRI) for detecting extrathoracic metastases in lung adenocarcinoma. Metastatic evaluations were feasible for 442 consecutive patients (M:F=238:204; mean age, 54 yr) with a lung adenocarcinoma who underwent PET/CT (CT, without IV contrast medium injection) plus contrast-enhanced brain MRI. The presence of metastases in the brain was evaluated by assessing brain MRI or PET/CT, and in other organs by PET/CT. Diagnostic efficacies for metastasis detection with PET/CT plus brain MRI and with PET/CT only were calculated on a per-patient basis and compared from each other. Of 442 patients, 88 (20%, including 50 [11.3%] with brain metastasis) had metastasis. Regarding sensitivity of overall extrathoracic metastasis detection, a significant difference was found between PET/CT and PET/CT plus brain MRI (68% vs. 84%; P=0.03). As for brain metastasis detection sensitivity, brain MRI was significantly higher than PET/CT (88% vs. 24%; P<0.001). By adding MRI to PET/CT, brain metastases were detected in additional 32 (7% of 442 patients) patients. In lung adenocarcinoma patients, significant increase in sensitivity can be achieved for detecting extrathoracic metastases by adding dedicated brain MRI to PET/CT and thus enhancing brain metastasis detection

Recent Advances in Nanotechnology Applied to Biosensors

In recent years there has been great progress the application of nanomaterials in biosensors. The importance of these to the fundamental development of biosensors has been recognized. In particular, nanomaterials such as gold nanoparticles, carbon nanotubes, magnetic nanoparticles and quantum dots have been being actively investigated for their applications in biosensors, which have become a new interdisciplinary frontier between biological detection and material science. Here we review some of the main advances in this field over the past few years, explore the application prospects, and discuss the issues, approaches, and challenges, with the aim of stimulating a broader interest in developing nanomaterial-based biosensors and improving their applications in disease diagnosis and food safety examination

Low exposure long-baseline neutrino oscillation sensitivity of the DUNE experiment

The Deep Underground Neutrino Experiment (DUNE) will produce world-leading neutrino oscillation measurements over the lifetime of the experiment. In this work, we explore DUNE's sensitivity to observe charge-parity violation (CPV) in the neutrino sector, and to resolve the mass ordering, for exposures of up to 100 kiloton-megawatt-years (kt-MW-yr). The analysis includes detailed uncertainties on the flux prediction, the neutrino interaction model, and detector effects. We demonstrate that DUNE will be able to unambiguously resolve the neutrino mass ordering at a 3$\sigma$ (5$\sigma$) level, with a 66 (100) kt-MW-yr far detector exposure, and has the ability to make strong statements at significantly shorter exposures depending on the true value of other oscillation parameters. We also show that DUNE has the potential to make a robust measurement of CPV at a 3$\sigma$ level with a 100 kt-MW-yr exposure for the maximally CP-violating values \delta_{\rm CP}} = \pm\pi/2. Additionally, the dependence of DUNE's sensitivity on the exposure taken in neutrino-enhanced and antineutrino-enhanced running is discussed. An equal fraction of exposure taken in each beam mode is found to be close to optimal when considered over the entire space of interest

A Gaseous Argon-Based Near Detector to Enhance the Physics Capabilities of DUNE

This document presents the concept and physics case for a magnetized gaseous argon-based detector system (ND-GAr) for the Deep Underground Neutrino Experiment (DUNE) Near Detector. This detector system is required in order for DUNE to reach its full physics potential in the measurement of CP violation and in delivering precision measurements of oscillation parameters. In addition to its critical role in the long-baseline oscillation program, ND-GAr will extend the overall physics program of DUNE. The LBNF high-intensity proton beam will provide a large flux of neutrinos that is sampled by ND-GAr, enabling DUNE to discover new particles and search for new interactions and symmetries beyond those predicted in the Standard Model