International Trade and CO2 Emissions: A Dynamic Panel Data Analysis by the STIRPAT Model

This paper focuses on the study of the effect of international trade on CO2 emissions. The study focuses on a dynamic panel of 176 countries over the period 1995-2012. On the first hand, we will proceed to the estimation of STIRPAT model. Then, we will test the effect of trade and trade intensity with developed countries on CO2 emissions. The results have been proven with The Environmental Kuznets Curve in the case of the total sample and for developed and developing countries. Concerning the case of the effect of international trade on CO2 emissions, the results show that international trade increases pollution in developed and developing countries. In the developing countries, pollution increases because of their trade with developed countries. However, if the developed countries trade together the CO2 emissions are reduced. Keywords: International Trade- CO2 Emissions- EC

Strain localization analysis using a multiscale model

In order to analyze the formability of steels in sheet metal forming, a ductility loss criterion is coupled with a multiscale model. The behavior at the mesoscopic (grain) scale is modeled by a large strain micromechanical constitutive law, which is then used in a self-consistent scale transition scheme. Hardening at the slip system level is taken into account through mean dislocation densities considered as internal variables. The determination of active slip systems and the calculation of plastic slip activity are achieved with help of a regularization technique drawn from viscoplastic formulations. The model is shown to be able to correctly simulate the macroscopic behavior for single-phase steels during both monotonic and sequential loading paths. Finally, Rice's localization criterion, based on the ellipticity loss of the elastic-plastic tangent modulus, is introduced and applied to determine forming limit diagrams (FLDs). The model allows us to obtain correct FLDs for monotonic as well as sequential loading paths. Pre-strain impact on FLDs is qualitatively reproduced as well.ArcelorMittal CNR

Modeling and simulation of architectured iron-based SMA materials

ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 2017), Snowbird, UT, SEP 18-20, 2017International audienceThe paper presents results of finite element analysis of architectured iron-based shape memory alloy (SMA) samples consisting of bulk SMA and void combined to different proportions and according to different geometric patterns. The finite element simulation uses a constitutive model for iron-based SMAs that was recently developed by the authors in order to account for the behavior of the bulk material. The simulation of the architectured SMA is then carried out using a unit cell method to simplify calculations and reduce computation time. For each unit cell, periodic boundary conditions are assumed and enforced. The validity of this assumption is demonstrated by comparing the average behavior of one unit cell to that of a considerably larger sample comprising multiple such cells. The averaging procedure used is implemented numerically, by calculating volume averages of mechanical fields such as stress and strain over each finite element model considered as a combination of mesh elements

Atmospheric pollution and economic growth : an empirical analysis of the Environnemental Kuznets curve in Tunisia (1970-2009)

In this paper, we examined the relationship between air pollution and economic growth for the case of Tunisia at the biginnig of 1970.Our study carried out in particular on the basis of verification of the hypothesis of environmental Kuznets curve by using time series data in VAR model

Intégration de la sémantique dans les Grammaires d'Interaction

Le présent travail est une étude qui s'inscrit dans le cadre d'un stage de recherche pour l'obtention du diplôme Master 2 de recherche en informatique pour le traitement automatique des Langues. L'étude s'intitule "Intégration de la sémantique dans les grammaires d'interaction". Il s'agit d'étudier l'interface syntaxe/sémantique dans les formalismes grammaticaux et de s'inspirer de cette étude pouThis work is done in the context of the Masters in Computer Science, specialization in "Natural Language Processing (NLP)". It concerns the "Integration of semantics in Interaction Grammars (IG)" and studies how the syntax/semantics interface used for other formalisms can be adapted to IG. The solution proposed is implemented in a parser called LEOPAR

Ellipticity loss analysis for tangent moduli deduced from a large strain elastic–plastic self-consistent model

In order to investigate the impact of microstructures and deformation mechanisms on the ductility of materials, the criterion first proposed by Rice is applied to elastic–plastic tangent moduli derived from a large strain micromechanical model combined with a self-consistent scale-transition technique. This approach takes into account several microstructural aspects for polycrystalline aggregates: initial and induced textures, dislocation densities as well as softening mechanisms such that the behavior during complex loading paths can be accurately described. In order to significantly reduce the computing time, a new method drawn from viscoplastic formulations is introduced so that the slip system activity can be efficiently determined. The different aspects of the single crystal hardening (self and latent hardening, dislocation storage and annihilation, mean free path, etc.) are taken into account both by the introduction of dislocation densities per slip system as internal variables and the corresponding evolution equations. Comparisons are made with experimental results for single and dual-phase steels involving linear and complex loading paths. Rice’s criterion is then coupled and applied to this constitutive model in order to determine the ellipticity loss of the polycrystalline tangent modulus. This criterion, which does not need any additional “fitting” parameter, is used to build Ellipticity Limit Diagrams (ELDs).ArcelorMittal Researc

Modeling of niobium precipitates effect on the Ni 47Ti 44Nb 9 Shape Memory Alloy behavior

Commercial Ni 47Ti 44Nb9 Shape Memory Alloy (SMA) is generally adopted for tightening applications thanks to its wide transformation hysteresis, compared with classical NiTi. Its sensibility to thermo-mechanical treatments allows it to be either martensitic or austenitic in a wide range of temperature, between -60 °C and 80 °C. A modeling of niobium precipitates effects on Ni 47Ti 44Nb9 SMA behavior is proposed. For this object, a two phase thermo-mechanical model is developed. It describes the global effective behavior of an elastoplastic inclusion (niobium precipitates) embedded within an SMA matrix. The constitutive law developed by Peultier et al. (2006) and improved by Chemisky et al. (2011) is adopted to model the matrix shape memory behavior. The elastoplastic constitutive law for inclusion is the one proposed by Wilkins with Simo and Hughes's radial return algorithm. The Mori-Tanaka scale transition scheme is considered for the determination of the effective constitutive equations. Obtained results highlight the effect of niobium precipitates on the thermomechanical behavior of Ni47Ti 44Nb9, and particularly on the corresponding hysteresis size. It appears that the niobium plasticity increases this hysteresis size. The developed constitutive law has been implemented in the ABAQUS Finite Element code and considered for the numerical prediction of the tightening pressure in a connection applicatio

Assessing the antimicrobial strength of Moroccan propolis from four regions on human infection-causing bacteria and yeast strains

This study aims to explore the potential of ethanolic extracts of propolis from different regions in Morocco as a means of combatting microbial infections. Specifically, we investigate the antimicrobial activity of these extracts against five distinct microbial strains and analyze the correlation between this activity and the polyphenol and flavonoid content of the extracts. The inhibitory effects of the extracts on Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans were evaluated by measuring the inhibition diameters, followed by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and the minimal fungicidal concentration (MFC). The study revealed that the ethanolic extract of Moroccan propolis displayed potent antibacterial and antifungal activity, with a greater sensitivity towards Staphylococcus aureus. The extracts\u27 antimicrobial activities were correlated with the concentration of flavonoids and polyphenols present in them. The results also suggest that propolis collected from Rabat and Agadir exhibited more substantial antimicrobial potential than that collected from Settat or Marrakech. Overall, the findings of this study provide valuable insights into the possibility of Moroccan propolis as an antimicrobial agent

A finite-element based numerical tool for Ni47Ti44Nb9 SMA structures design application to tightening rings

This paper deals with the design of Ni47Ti44Nb9 Shape Memory Alloy (SMA) tightening components. The tightening of an SMA ring on an elastic pipe is analyzed using the finite element code ABAQUS® and a UMAT subroutine developed in our group to model the specific behavior of Ni47Ti44Nb9 SMA. Main features of the thermomechanical model implemented in this UMAT routine are briefly recalled. Numerical predictions are validated using experimental tightening pressures obtained on a test bed developed in this work. The validation strategy is documented and the results for different ring thicknesses are presented. This finite element tool is then applied to a parametric study of the influence of ridges on the tightening pressure. Eventually, geometrical defects like out of roundness are considered

Modélisation micromécanique de l'effet de précipités sur le comportement d'un polycristal en alliage à mémoire de forme

Le processus de fabrication des AMF conduit à la formation de précipités. Des études expérimentales montrent leur influence sur les propriétés de la transformation martensitique. Le développement d'un modèle micro-mécanique utilisant une transition d'échelle de type Mori-Tanaka permet de prendre en compte l'effet des précipités à l'échelle intra-granulaire. Une seconde transition d'échelle de type auto-cohérente permet le passage de l'échelle du grain à celle du polycristal