32 research outputs found
DAPHNE: a large-acceptance tracking detector for study of photoreactions at intermediate energies
No full textA large-acceptance (94% of 4π sr) hadron detector capable of handling multiparticle final states is described. The track reconstruction capability, energy resolution, particle identification capability and neutral-particle detection efficiency of the detector are discussed and the results of tests shown. Tests have been performed both with cosmic rays and in a realistic experimental situation using a 500 MeV photon beam impinging on hydrogen and deuterium targets
[catalog] Catalog der Gemälde-Sammlungen aus dem Nachlasse der Freifrau von und zu Brenken ... und des Herrn Julius Baron Bechade ... Gemälde niederländischer, italienischer und deutscher Meister des XIV-XVIII Jahrhunderts : Versteigerung zu Köln den 1 April ... und den 2 April ... durch J. M. Heberle ...
No full textGeannoteerd met prijzen en kopersnamen (L. Soullié)Bijzondere collectie
The Influence Of Carbon And Oxygen Content On The Martensitic Transformation Temperatures And Enthalpies Of Niti Shape Memory Alloy
No full textThe martensitic transformation temperatures and enthalpies of NiTi shape memory alloy strongly depend on the content of nickel and on carbon and oxygen impurities. Nickel stabilizes the high-temperature phase while carbon and oxygen enrich the surrounding matrix with nickel. In this work it is shown that, as a consequence, the martensitic transformation temperatures and enthalpy changes are lower than specially prepared low-contamination reference samples. Furthermore, the enthalpy changes increase linearly with increasing peak martensitic transformation temperature. This means that the lower the enthalpies, the lower is the peak martensitic transformation temperature suggesting that at some lower temperature no phase change should occur. © 2007 Elsevier B.V. All rights reserved.481-4821-2 C639642J. Otubo, P.R. Mei, S. Koshimizu, L.G. Martinez, In: The Third Pacific Rim International Conference on Advanced Materials and Processing (PRICM 3), M.A. Imam, R. DeNale, S. Hanada, Z. Zhong, D.N. Lee (Eds.), The Minerals, Metals & Materials Society, TMS, vol. 1, 1998, pp. 1063-1068Otubo, J., Rigo, O.D., Moura Neto, C., Kaufman, M.J., Mei, P.R., (2003) J. Physique IV (France), 112, pp. 873-876Otubo, J., Rigo, O.D., Moura Neto, C., Kaufman, M.J., Mei, P.R., (2004) Mater. Res., 7, pp. 263-267Otubo, J., Rigo, O.D., Moura Neto, C., Mei, P.R., (2006) Mater. Sci. Eng. A, 438-440, pp. 679-682Rigo, O.D., Otubo, J., Moura Neto, C., Mei, P.R., (2005) J. Mater. Process. Technol., 162-163, pp. 116-120O.D. Rigo, J. Otubo, P.R. Mei, Proceedings of the 60° Congresso Anual da ABM, Belo Horizonte, MG, Brazil, 25-28 July, 2005, 2412-2420Shugo, Y., Yamauchi, K., Miyagawa, R., Honma, T., (1982) Bull. Res. Inst. Miner. Dress. Metall. (Tohoku Univ.), 38, pp. 11-20Olier, P., Barcelo, F., Bechade, J.L., Brachet, J.C., Lefevre, E., Guenin, G., (1997) J. Physique IV (France), 7 (C5), pp. 143-148Frenzel, J., Zhang, Z., Neuking, K., Eggeler, G., (2004) J. Alloys Compd., 385, pp. 214-223Sawaguchi, T., Kausträter, G., Yawny, A., Wagner, M., Eggeler, G., (2003) Met. Mater. Trans., 34 A, pp. 2847-2859ASTM F-2063-00, Standard specification for wrought nickel-titanium shape memory alloys for medical devices and surgical implants, 2000Verhoeven, J.D., (1975) Fundamental of Physical Metallurgy, , John Wiley & Sons pp. 490-49
Les trois accents graphiques utilisés dans la transcription du français (de la Renaissance à nos jours, à travers l'étude des dictionnaires de l'Académie française)
No full textLa langue française utilise, dans sa forme écrite, des accents : aigus, graves et circonflexes. Ces petites marques graphiques ont connu de nombreuses péripéties avant de s'imposer dans notre orthographe. Elles ont occupé des emplois divers, inspirés de leur usage chez les grammairiens grecs et latins. Puis l'Académie française les a progressivement intégrées dans ses Dictionnaires et chacune d'elles s'est vue attribuer un ou plusieurs rôles spécifiques. Or, à notre époque, les accents semblent en voie de disparition non seulement dans l'écriture manuscrite mais également sur les imprimés ou les écrans. L'auteur de ce travail a voulu essayer de comprendre pourquoi les accents étaient négligés, oubliés, déformés. Il constate que de nombreux Français ressentent un réel attachement pour ces signes qui, tout en conservant un rôle phonogrammique souvent important, sont aussi des traces du passé qui nous racontent la longue aventure d'un mot.The French language uses, in its written shape, acute, grave and circumflex accents. These small graphic symbols knew numerous events before prevailing in our spelling. They occupied different uses, inspired by their usage with Greek and Latin grammarians. Then the French Academy gradually integrated them into its dictionaries and each of them was attributed one or several specific roles. Nowadays, accents seem to be in the process of disappearance, not only in handwriting but also on printed documents or screens. The author of this work wanted to try to understand why accents were neglected, forgotten or deformed. He notices that French people have a real affection for these signs which, while preserving an important phonetic role, are also remnants that tell us the long adventure of a word.PARIS4-BU Serpente (751052129) / SudocSudocFranceF
Orientation relationship in various 9%Cr ferritic/martensitic steels–EBSD comparison between Nishiyama–Wassermann, Kurdjumov–Sachs and Greninger–Troiano
No full textSimultaneous DAFS and XAFS analyses to evidence the Y- and Ti-species in nano-structured ODS steels
No full textInternational audienceTo characterize the microstructure of neutron irradiated materials, various experimental tools are available at the present time in nuclear environment:SEM, TEM, APT, RBS and NRA… However, these techniques are local probes and bring information for an extremely limited sample volume which could be not representative of the whole volume. Therefore, a good statistic can only be obtained by performing many examinations which are very time consuming
Characterizations with the MARS beamline (synchrotron SOLEIL) of materials irradiated in nuclear reactors
No full textInternational audienceMARS (Multi-Analyses on Radioactive Samples) is the X-ray bending magnet beamline of the French synchrotron facility SOLEIL dedicated to the study of radioactive matter. The MARS beamline aims at extending the possibilities of synchrotron based X-ray characterizations towards a wider variety of radioactive elements (et61537;et61484;et61472;et61538;et61484;et61472;et61543; and n emitters). Thus, its specific and innovative infrastructure has been optimized to carry out analyses on radioactive materials with activities up to 18.5 GBq per sample. This beamline, which has been built thanks to a close partnership and support by the CEA, has been designed to provide X-rays in the energy range of 3.5 keV to 35 keV. Three main techniques are progressively proposed on MARS beamline transmission and high-resolution powder X-ray diffraction (respectively T-XRD and HR-XRD), X-ray absorption spectroscopy (XAS) and X-ray fluorescence (XRF).After the preliminary experiences performed on un-irradiated samples, this presentation deals with recent results obtained on the MARS beamline, thanks to very powerful and useful improvements brought to the experimental set-up of the beamline and to various materials irradiated in nuclear reactors Oxide dispersion-strengthened (ODS) steels at high doses and also Zr based alloys irradiated in Pressurized Water Reactors up to 7 PWR cycles.Results concerning secondary phases evolutions as a function of irradiation doses for both ODS and Zr based alloys will be presented using XRD, but also experiences using XAS especially on ODS will be given.Finally, future prospects and main objectives concerning the evolution of the beamline and studies on irradiated materials will be discussed
Lanthanum- and Oxygen-Deficient Crystal Structures of Oxide–Ion Conducting Apatite-Type Silicates
No full textInternational audienceThe structural change of La9.332x(SiO4)6O23x with increasing x value was investigated by means of laboratory X-ray powder diffraction (CuKa1). Crystal structures of the three types of specimens with x50, 0.06, and 0.085 were refined by the Rietveld method, with the anisotropic displacement (U) parameters being assigned for all atoms. Each crystal structure was composed of three types of polyhedra: La1O9, La2O7, and SiO4. With increasing x value, the occupancies (g) of both La1 and La2 sites decreased steadily. The La vacancies were charge balanced by the deficiency of the mobile O atoms that were not covalently bonded to Si atoms. The polyhedral volume of La2O7 decreased steadily about 0.7% with a decrease of the g(La2) value from 0.995 to 0.982. On the other hand, the polyhedral volume of La1O9 showed an increase of about 1.0%with a decrease of the g(La1) value from 0.841 to 0.818. The marked difference in deformation behavior of the two types of polyhedra could be attributable to the distinction in site occupancies between La1 [g(La1)o0.85] and La2 [g(La2)40.98]. For the mobile O atoms, the displacement magnitudes, being evaluated from the U parameters, decreased steadily with increasing x value. The positional disordering of these atom
Effects of Impurities Content (Oxygen, Carbon, Nitrogen) on Microstructure and Phase Transformation Temperatures of Near Equiatomic TiNi Shape Memory Alloys
No full textInvestigation of precipitation is performed on several near equiatomic TiNi alloys elaborated by arc melting or by powder metallurgy (combustion synthesis mode). These alloys contain various amount of impurities (oxygen, carbon , nitrogen). We show that such impurities result in both oxides (Ti4Ni2Ox, with x ≤ 1) and carbonitrides (TiCxN1-x, with ≤ 1) precipitation. X-ray diffraction measurements are performed on residues of electrochemical extraction to determine the structure and the lattice parameters of these precipitates. The precipited fractions are quantified for various amount of impurities by image analysis. A very good correlation is obtained between the nominal content of impurities determined by chemical analysis and the precipited fraction measured by image analysis and X-ray measurements. Our results indicate that almost all the nominal oxygen has precipited to form Ti4Ni2O type oxides.
As a consequence, an increase of the impurities content in near equiatomic TiNi alloys implies a lowering of the phase transformation temperatures. This phenomenon is attributed to the precipitates stoichiometry which induces a deficit of titanium content in solid solution.. On the other hand, we find that fine precipitation improve the grain size reduction during hot working. Possible explanation is that the precipitates act as grain refiners through a "pinning" or a "grinding" process
