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Troyon M.,CNRS Nanosciences Research Laboratory | Abbes F.,University of Reims Champagne Ardenne | Garcia Guzman J.A.,Pontifical Bolivarian University

Kaupp and Naimi-Jamal (2010) claimed that the analysis of published loading curves reveals the exponent 3/2 to the depth for nanoindentations with sharp pyramidal or conical tips. To demonstrate this, they plotted the load vs. the penetration depth to the power 3/2. We show, through examples, the authors' assertion is not credible because the methodology used is misleading and it cannot be asserted that the exponent 3/2 has a universal validity that applies to all kinds of materials. © Wiley Periodicals, Inc. Source

Mouetsi S.,University of Oum El Bouaghi | El Hdiy A.,CNRS Nanosciences Research Laboratory
Journal of Applied Physics

The 1/f noise is investigated in an epitaxial AlGaAs/GaAs/AlGaAs heterostructure in the temperature range of [4-300 K]. The sample is biased at very low voltage to avoid velocity saturation at low temperature. Hooge parameters are determined at very low frequency assuming the absence of correlation between existing noise sources. These parameters are weakly fluctuating but do not show clear variation with temperature; αH varies in the range of 10-5 to 10-2, which are higher than theoretical values based on the mobility fluctuations. γ remains close to unity. αH and γ values suggest that the 1/f noise originates from the mobility fluctuation due to the lattice scattering, but the difference between theoretical and experimental αH suggests the existence of the noise originating from electron number fluctuations. © 2013 AIP Publishing LLC. Source

Guillard T.,Reims University Hospital Center | Guillard T.,University of Reims Champagne Ardenne | Lebreil A.-L.,University of Reims Champagne Ardenne | Hansen L.H.,Reims University Hospital Center | And 9 more authors.
Antimicrobial Agents and Chemotherapy

We developed a two-step PCR-based strategy to detect genes encoding OqxAB, allowing a specific assignment of Tn6010-associated oqxAB in Enterobacteriaceae. Chromosomal location in this setup was confirmed by hybridization with I-CeuI-restricted genomes. This approach led us to find that Klebsiella sp. and Raoultella sp. reference strains chromosomally carried oqxAB. Copyright © 2015, American Society for Microbiology. All Rights Reserved. Source

Khanna P.K.,Indian Defence Institute of Advanced Technology | Kate K.,CNRS Nanosciences Research Laboratory | Dhanabalan K.,Indian Defence Institute of Advanced Technology | Banerjee S.,Indian Defence Institute of Advanced Technology | And 3 more authors.
Journal of Nanoscience and Nanotechnology

Herein we describe synthesis of ZnO nanoparticles by using alkaline solution of ZnX 2 (X = NO 3, Cl) under ultrasound energy of 20 KHz. The reaction can be completed in about 1-2 hours. As prepared powders were analyzed by XRD measurement to find that the product is hexagonal phase pure ZnO. UV-Visible measurement of aq. solution showed absorption band at ̃365 nm and photoluminescence (PL) indicated multiple bands in visible region due to deep traps owing to high temperature sintering. The hydrophilicity can be imparted by use of a suitable polyelectrolyte. Freshly prepared samples showed good dispersion in aqueous and alcoholic medium. The thick films derived from the ZnO nano-particles showed excellent sensing for hydrogen sulphide gas. Copyright © 2012 American Scientific Publishers. Source

Levi S.,CNRS Laboratory of Engineering and Materials Science | Rousse C.,CNRS Laboratory of Engineering and Materials Science | Mancier V.,CNRS Laboratory of Engineering and Materials Science | Michel J.,CNRS Nanosciences Research Laboratory | Fricoteaux P.,CNRS Laboratory of Engineering and Materials Science
Journal of Materials Research

Copper-silver core-shell nanowires were synthesized using a combination of two methods: electrodeposition in a polycarbonate membrane as a template for the synthesis of a copper core and a galvanic replacement reaction for the elaboration of a silver shell. A comparative study between aqueous and ionic liquid media was performed for the silver shell elaboration. The kinetics of the reaction in both media was monitored by using energy dispersive x-ray spectroscopy. The shape and size of the nanowires were observed by both scanning electron microscopy and transmission electron microscopy. The core-shell structure was determined by electron energy loss spectroscopy analyses for the Cu90Ag10 composition. A homogenous silver shell was formed in aqueous media. Whereas in ionic solvent, well defined silver crystals were obtained at the surface of the nanowires but without a total formation of a silver shell structure. © Materials Research Society 2015. Source

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