Mines ParisTech

About: Mines ParisTech is a education organization based out in Paris, France. It is known for research contribution in the topics: Finite element method & Microstructure. The organization has 6564 authors who have published 11676 publications receiving 359898 citations. The organization is also known as: École nationale supérieure des mines de Paris & École des mines de Paris.

Driving Force and Logic of Development of Advanced High Strength Steels for Automotive Applications

Abstract: The major scientific and technological advances and breakthroughs of advanced high strength steels (AHSS) were achieved due to the strong demands of automotive industry. The development of AHSS began in the early 1980s with the aim of improving passenger safety and weight-saving. The present paper presents the driving forces and logic of development of various AHSS for automotive applications since 1980s. The importance of crash performance, weight-saving, formability, and rigidity are critically reviewed for the development of new steel grades for automotive applications. The logical sequences of the development of dual phase (DP) steel, transformation induced plasticity (TRIP) steels, tempered DP steels, complex phases (CP) steels, Ferrite-Bainite steels, hot-stamping technology, twinning induced plasticity (TWIP) steels, Quench and Partitioning (Q&P) steels, Medium Mn steels, and steels–polymer composites are presented.

Sequential Data Assimilation Techniques in Oceanography

Abstract: Summary We review recent developments of sequential data assimilation techniques used in oceanography to integrate spatio-temporal observations into numerical models describing physical and ecological dynamics. Theoretical aspects from the simple case of linear dynamics to the general case of nonlinear dynamics are described from a geostatistical point-of-view. Current methods derived from the Kalman filter are presented from the least complex to the most general and perspectives for nonlinear estimation by sequential importance resampling filters are discussed. Furthermore an extension of the ensemble Kalman filter to transformed Gaussian variables is presented and illustrated using a simplified ecological model. The described methods are designed for predicting over geographical regions using a high spatial resolution under the practical constraint of keeping computing time sufficiently low to obtain the prediction before the fact. Therefore the paper focuses on widely used and computationally efficient methods.

Coagulation and flocculation of dye-containing solutions using a biopolymer (Chitosan)

Abstract: Chitosan, dissolved in acetic acid, was used for the coagulation–flocculation of an anionic dye (Reactive Black 5). In acidic solutions protonated amine groups of chitosan attract dye sulfonic groups. Increasing chitosan dosage increases dye removal up to a concentration resulting in complete neutralization of anionic charges; above, the excess of cationic charges leads to suspension re-stabilization. Process efficiency increases with decreasing the initial pH of dye solution: the molar ratio between dye molecules and amine groups ([ n ]) respects the stoichiometry between sulfonic functions and protonated amine groups at initial pH 5; at initial pH 3 a possible dye aggregation phenomenon results in higher molar ratio [ n ]. The coefficient [ n ] depends on both the pH and the molecular weight of chitosan. The main mechanism for dye coagulation with chitosan sounds to be charge neutralization at acidic pH.