ParisTech

About: ParisTech is a education organization based out in Paris, France. It is known for research contribution in the topics: Finite element method & Residual stress. The organization has 1888 authors who have published 1965 publications receiving 55532 citations. The organization is also known as: Paris Institute of Technology & ParisTech Développement.

Use of a Modification of the Patel-Teja Equation of State + van der Waals-Platteeuw Theory Based Model for Predicting Hydrate Phase Boundary of Methane - Ethylene Glycol - Water System from Ice Point Data of Aqueous Solution

Abstract: A major concern with the oil/gas pipelines and production/processing facilities is the possibility of flow restriction and blockage due to gas hydrate formation, which can lead to serious operational, economic and safety problems. Organic inhibitors such as methanol and ethylene glycol are normally used for preventing gas hydrate formation. Accurate knowledge of hydrate phase equilibrium in the presence of inhibitors is therefore crucial to avoid gas hydrate formation problems and to design/optimize production, transportation and processing facilities. Experimental data are needed for developing models capable of predicting hydrate phase behavior. In general, measuring hydrate phase equilibrium in the presence of inhibitor is more difficult than measuring ice point of inhibitor aqueous solution, particularly at high concentrations of inhibitor. This is partly due to the fact that the presence of inhibitor shifts hydrate phase boundaries to high pressures, which leads to difficulties in hydrate phase equilibria measurements. In this work, we examine the need for hydrate phase equilibrium data in the presence of inhibitor (ethylene glycol) aqueous solutions for tuning parameters of a thermodynamic model based on a modification of the Patel-Teja equation of state + van der Waals-Platteeuw theory. We consider two cases for tuning: use of ice point data or, using hydrate phase equilibrium data. The results show that using only ice point data of inhibitor aqueous solution for tuning thermodynamic model can lead to acceptable predictions of hydrate phase equilibrium in the presence of inhibitor and therefore experimental hydrate phase equilibrium data are not strictly indispensable.

Analysis of the mechanisms of idiopathic scoliosis progression using finite element simulation

Abstract: Because of the number of factors involved, the mechanisms of idiopathic scoliosis progression are still not fully understood, particularly the factors that induce the well known torsion phenomenon ...

Adhesion of thermal barrier coatings systems after long term oxidation : influence of preoxidation temperature and surface state of the bond coat

Abstract: The aim of this study was to determine the effect of the pre-oxidation temperature and surface state of the bond coat on the microstructure of the oxide scale formed at the first stages of oxidation and on its adhesion after subsequent long-term oxidation (1000 h) at 1100–C. Short-term isothermal oxidations of 1 h were performed at several temperatures (900–C, 1100–C) on a Pt-modified NiAl bond coat with two different surface states (as-aluminized or grit-blasted) deposited on a superalloy (AM1). The adherence of the different systems after an additional isothermal ageing treatment in air at 1100–C for 1000 h, was compared in order to deduce the initial oxide scale leading to the best resistance to spallation. Characterization was performed using SEM and analytical TEM. The crystalline structure and the morphology of the as-formed oxide scale were studied as a function of the different parameters.