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Villeurbanne, France

The Institut National des science Appliquées de Lyon or INSA Lyon is a Grande École d'Ingénieurs. INSA Lyon is ranked among the top universities of Science and Technology in Europe, pluridisciplinary and international, at the heart of the European Higher Education Area.The school was founded in 1957 to train highly qualified engineers, support continuing education, and conduct research and testing. The five-year curriculum aims at training engineers who possess human qualities and are well versed in the primary areas of science and engineering. Graduates from INSA are called "Insaliens".The education is organised as follows: the first cycle: highly selective, students acquire the necessary scientific background for future engineering studies. the second cycle: students are given the choice between 12 fields of specialisation. They may pursue a Phd upon completion of the 5-year curriculum.The university is located on the La Doua-Lyontech campus, home of science-related universities. La Doua is located in Villeurbanne, a suburb of Lyon. Wikipedia.

Auvergne R.,National Graduate School of Chemistry, Montpellier | Caillol S.,National Graduate School of Chemistry, Montpellier | David G.,National Graduate School of Chemistry, Montpellier | Boutevin B.,National Graduate School of Chemistry, Montpellier | And 2 more authors.
Chemical Reviews | Year: 2014

The works undertaken to obtain either partially or fully biobased epoxide materials are studied. The reaction between the phenate ion and ECH 2 reveals two competitive mechanisms, one-step nucleophilic substitution with cleavage of the C-Cl bond and a two-step mechanism based on ring opening of ECH (2) with ArO- (1') followed by intramolecular cyclization (SNi) of the corresponding alcoholate, containing one atom of chlorine in the β-position, formed in situ. Depending on the substituent position or nature in the phenol, it takes 6-20 h at reflux or 24-26 h at room temperature to complete the reaction. The reaction of ECH with an alcohol is more difficult, with many side reactions, since this reaction generates new alcohol groups with similar pKa values which are able to react with the epoxy group of ECH, thus leading to its homopolymerization. Epoxies are able to react with (meth)acrylic acid to give formulations for coating applications or vinyl ester monomers and networks after radical polymerization.

Thermal load calculation based on dynamic models is widely used in simulation software and it is the method recommended by ASHRAE (American Society of Heating, Refrigeration and Air-Conditioning Engineers) and CEN (European Committee for Standardization, in French: Comité Européen de Normalisation). The principle is to make the heat balance for the air volume of a room space considered at uniform temperature and to calculate from this equation the load, i.e. the power needed to obtain the required indoor temperature. The problem is that, by doing so, the physical causality is not respected. If the model is approximated by a piece-wise linear dynamical system, this procedure results in an improper transfer function in the case of non-negligible thermal capacity of the indoor air. In order to point out this problem, a method to obtain state-space and transfer function models from thermal networks is introduced. Then, the transfer function representation is employed to show that changing the physical causality results in an improper transfer function. The practical consequence is that when the space temperature has a step variation, the calculated load tends to infinity if the simulation time step approaches zero. The issue of causality may be a problem in equation-based simulation software, such as Modelica, in which the equations do not represent causal relations: a wrong choice of the causality in a balance equation may result in an improper transfer functions. © 2012 Elsevier Ltd.

Maire E.,INSA Lyon
Annual Review of Materials Research | Year: 2012

This article reviews studies in which X-ray tomography has been used to characterize the cellular microstructure or the deformation mechanisms of highly porous materials. The technique is suitable for imaging these materials with much detail. Such images can also be used to quantify the micro-structure (wall thickness and cell size distribution and tortuosity of the porous network). Finally, the methods available to produce finite element meshes from the three-dimensional images are presented and discussed in light of one example. © Copyright ©2012 by Annual Reviews. All rights reserved.

Renard Y.,INSA Lyon
Computer Methods in Applied Mechanics and Engineering | Year: 2013

In this paper, some new generalized Newton's methods for the resolution of elastostatic frictional contact problem approximated by finite elements are presented and compared to existing ones. A numerical experimentation is performed to compare the different methods, especially with respect to the sensitivity to the method parameter. Two different strategies to approximate the contact and friction condition are considered: a nodal and an integral one. Existence and uniqueness results of the solution to the discretized problem are also discussed. © 2012 Elsevier B.V.

Antoni J.,INSA Lyon
Mechanical Systems and Signal Processing | Year: 2016

A classical symptom of rotating machines faults in vibration signals is the presence of repetitive transients, whose distinctive signature is both impulsive and cyclostationary. Typical approaches for their detection proceed in the time or frequency domains, with tools such as the spectral kurtosis, the kurtogram, or the envelope spectrum. The object of this paper is to extend and somehow connect these concepts in order to capture the signature of repetitive transients in both domains. Motivated by ideas borrowed from the field of thermodynamics where transients are seen as departures from a state of equilibrium, it is proposed to measure the negentropy of the squared envelope (SE) and of the squared envelope spectrum (SES) of the signal. This defines the SE infogram, the SES infogram, and their average which is theoretically maximum for a Dirac comb according to Hirschman's uncertainty principle. It is demonstrated that the joint consideration of the infograms significantly extends the domain of applicability of the kurtogram, in particular to situations corrupted with impulsive noise or when the relaxation time of the transients is low as compared to their rate of repetition. This is illustrated on both synthetic and actual vibration signals. This paper is part of a special issue in honor of Professor Simon Braun and pays tribute to his early contribution to the field of mechanical signature analysis. © 2015 Elsevier Ltd. All rights reserved.

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