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Belvaux, Luxembourg

Drillet J.,ArcelorMittal | Valle N.,CRP Gabriel Lippmann | Iung T.,ArcelorMittal
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2012

The current trend toward producing lighter vehicles in the automotive industry is driven by the need to conform to the new exhaust emission control regulations. This objective presents a challenge to steel manufacturers. The difficulty lies in designing new alloys with an optimum strength/formability/ cost balance for the various components. Here, the key to success lies in controlling the steel microstructure and especially the phase transformations at the smallest possible scale. Among the different alloying elements, light elements such as carbon and boron are of prime importance due to their major effects on the kinetics of phase transformations. Characterization tools combining high spatial and analytical resolution such as secondary ion mass spectrometry (SIMS) and field emission gun-transmission electron microscopy (TEM) were used. In this article, the examples presented are as follows. (1) Boron segregation and precipitation effects to control hardenability in martensitic steels. (2) Local carbon distribution in advanced high-strength steels, with a specific emphasis on martensite tempering. Links have been established between the boron and carbon distribution and the formability. © 2012 The Minerals, Metals & Materials Society and ASM International.

Istoan P.,CRP Gabriel Lippmann | Istoan P.,University of Rennes 1
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

To support the constant evolution of modern enterprises, business process models are becoming exponentially more complex. Business process composition is regarded as a flexible mechanism capable to cope with this issue and make processes easier to understand, maintain and evolve. Composition operators are the foundation and the enablers of process composition. BPMN, the standard language for modelling business processes, is lacking such composition operators. Therefore, in this paper, we propose to extend the BPMN standard with a set of composition operators and with the concept of composition interface. © 2012 Springer-Verlag.

Guennou M.,CRP Gabriel Lippmann | Bouvier P.,Stendhal University | Bouvier P.,European Synchrotron Radiation Facility | Toulemonde P.,CNRS Neel Institute | And 6 more authors.
Physical Review Letters | Year: 2014

The interaction of coexisting structural instabilities in multiferroic materials gives rise to intriguing coupling phenomena and extraordinarily rich phase diagrams, both in bulk materials and strained thin films. Here we investigate the multiferroic BiMnO3 with its peculiar 6s2 electrons and four interacting mechanisms: electric polarity, octahedra tilts, magnetism, and cooperative Jahn-Teller distortion. We have probed structural transitions under high pressure by synchrotron x-ray diffraction and Raman spectroscopy up to 60 GPa. We show that BiMnO3 displays under pressure a rich sequence of five phases with a great variety of structures and properties, including a metallic phase above 53 GPa and, between 37 and 53 GPa, a strongly elongated monoclinic phase that allows ferroelectricity, which contradicts the traditional expectation that ferroelectricity vanishes under pressure. Between 7 and 37 GPa, the Pnma structure remains remarkably stable but shows a reduction of the Jahn-Teller distortion in a way that differs from the behavior observed in the archetypal orthorhombic Jahn-Teller distorted perovskite LaMnO3. © 2014 American Physical Society.

Toledano P.,University of Picardie Jules Verne | Guennou M.,CRP Gabriel Lippmann | Kreisel J.,CRP Gabriel Lippmann | Kreisel J.,University of Luxembourg
Physical Review B - Condensed Matter and Materials Physics | Year: 2014

The symmetry of boundaries between ferroelectric, ferroelastic, and antiphase domains is a key element for a theoretical understanding of their properties. Here, we derive this symmetry from their organic relation to the symmetry of the primary transition order parameters. The domain wall symmetries are shown to coincide with directions of the order-parameter n-dimensional vector space, corresponding to sum of the vectors associated with adjacent domain states. This property is illustrated by the determination of the maximal symmetries of domain walls in BaTiO3, LaAlO3, SrTiO3, and Gd2(MoO4)3. Besides, the domain pattern in YMnO3 is interpreted as resulting from an annihilation-creation process, the annihilation of the antiphase domain walls creating six ferroelectric domain walls merging at a single point. © 2014 American Physical Society.

Hody S.,University of Liege | Leprince P.,University of Liege | Sergeant K.,CRP Gabriel Lippmann | Renaut J.,CRP Gabriel Lippmann | And 3 more authors.
Medicine and Science in Sports and Exercise | Year: 2011

Introduction: Delayed-onset muscle soreness (DOMS), a condition triggered by eccentric exercise, affects muscle cells at a biochemical level in a poorly understood fashion. The objective of the present study was to examine human muscle proteome modifications induced by strenuous eccentric exercises after a specific training aimed to prevent DOMS. Methods: Biopsy samples of the rectus femoris were obtained from healthy human volunteers in three successive conditions: 1) at rest, 2) 24 h after an injuring exercise protocol consisting of three series of 30 maximal contractions of the quadriceps on an isokinetic dynamometer, and 3) 24 h after a similar exercise bout preceded either by five eccentric training sessions or by no training. RESULTS: Muscle damage was assessed before and 1 d after each maximal eccentric test by comparing three indirect markers: plasma activity of creatine kinase, muscle stiffness, and subjective pain intensity. Compared with the first eccentric test, those markers were reduced after the second test and further reduced if this second test followed the eccentric training, thus confirming the protective effect of such training. Muscle protein extracts were subjected to a two-dimensional difference gel electrophoresis proteomic analysis coupled with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry protein identification. Surprisingly, we observed that myosin heavy chains decreased after the first eccentric test and were reduced further with other contractile proteins after the second test. Furthermore, the expression of several glycolytic enzymes decreased only after the second test, which was preceded by a specific training. Conclusions: These findings suggest that the eccentric training resulted in a switch to oxidative metabolism, which may be associated with protection from DOMS. © 2011 by the American College of Sports Medicine.

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