The Experts below are selected from a list of 5892 Experts worldwide ranked by ideXlab platform
James E Krzanowski - One of the best experts on this subject based on the ideXlab platform.
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microStructure and vacuum tribology of tic ag composite coatings deposited by magnetron sputtering pulsed laser deposition
Surface & Coatings Technology, 2002Co-Authors: J L Endrino, J J Nainaparampil, James E KrzanowskiAbstract:Abstract Composite titanium carbide–silver films have been co-deposited by magnetron sputtering-pulsed laser deposition (MSPLD) to study their friction and wear properties in vacuum. The films deposited were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The silver content in the films ranged from 6 to 46 at.%. Structural characterization of the films revealed that Ag had a nano-crystalline Structure when dispersed in the film, but larger crystallites of Ag (∼50–200 nm) also formed on the surface. Films with higher Ag contents showed evidence of higher diffusion rates, leading to a Coarser Structure and greater surface coverage. Pin-on-disk friction tests were performed under vacuum to observe the friction and wear behavior of these films. Friction was lower with higher Ag content, but wear was higher; the optimal Ag concentration was found to be 15%. SEM images from the surface of the films and wear tracks were obtained to understand the morphology of this type of composite ceramic coating, and revealed Ag layers in the wear track elongated in the direction of wear. Based on these results, the significance of silver as a friction-reducing agent in vacuum environments was demonstrated.
Thierry Mateille - One of the best experts on this subject based on the ideXlab platform.
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Indirect effects of the bacterial soil aggregation on the distribution of Pasteuria penetrans , an obligate bacterial parasite of plant-parasitic nematodes
Geoderma, 2001Co-Authors: K.r. Dabiré, Robin Duponnois, Thierry MateilleAbstract:The effects of the inoculation of two fluorescent Pseudomonas strains (P. mendocina and Pseudomonas sp.) on the soil aggregation in the rhizosphere have been tested. Their indirect effects on the conservation of spores of Pasteuria penetrans, a bacterial endospore-forming parasite of plant-parasitic nematodes Meloidogyne spp., and on the infection of Meloidogyne javanica juveniles were investigated. The amount of rhizosphere soil adhering to the root systems was higher in the soils inoculated with both bacterial strains P. mendocina and Pseudomonas sp. However, juveniles of Meloidogyne were more numerous in the soil inoculated with Pseudomonas sp. and the multiplication rate of M. javanica did not differ regardless of the treatment. Furthermore, the proportion of juveniles infested by P. penetrans spores was highest in soil inoculated with P. mendocina (B23). The spores were distributed, following a similar pattern in the soil aggregate fractions excepted in the soil inoculated with P. mendocina (B23). In the soil inoculated with B23, about 50% of the spores present in the rhizosphere were retained in the Coarser Structure characterized by aggregates >200 μm. The role of the bacterial extracellular polysaccharides on soil and spores aggregation and on the Meloidogyne infection may explain these results.
Wen Yang - One of the best experts on this subject based on the ideXlab platform.
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structural characterization and mechanical behavior of a bivalve shell saxidomus purpuratus
Materials Science and Engineering: C, 2011Co-Authors: Neima Kashani, Xiaowu Li, G P Zhang, Wen Yang, M A MeyersAbstract:article i nfo Structure Hardness Compression Shells The Structure and mechanical behavior of Saxidomus purpuratus bivalve shell were investigated. XRD results show that the only form of calcium carbonate present in the shell is aragonite. The inner and middle layers have a cross-lamellar Structure, while the outer layer has porosity and does not have tiles, but instead has 'blocky' regions. The hardness of middle and inner layer are close in both plane view and cross section, but the hardness of outer layer is significantly less, especially in the plane view. The compressive strengths with loading along the three orientations were established and significant differences were found. The Weibull strength at 50% of the probability of failure varies between 59 and 148 MPa and is dependent on the loading orientation and in condition of shell (dry vs. hydrated). These differences are interpreted in terms of the anisotropic Structure and Coarser Structure of the external layer.
Joakim Odqvist - One of the best experts on this subject based on the ideXlab platform.
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effect of carbon activity and powder particle size on wc grain coarsening during sintering of cemented carbides
International Journal of Refractory Metals & Hard Materials, 2014Co-Authors: Ida Borgh, Peter Hedstrom, Annika Borgenstam, John Agren, Joakim OdqvistAbstract:Liquid-phase sintering is an important step in the production of cemented carbides. During sintering, the average WC grain size increases, leading to a Coarser Structure, which affects the performa ...
J L Endrino - One of the best experts on this subject based on the ideXlab platform.
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microStructure and vacuum tribology of tic ag composite coatings deposited by magnetron sputtering pulsed laser deposition
Surface & Coatings Technology, 2002Co-Authors: J L Endrino, J J Nainaparampil, James E KrzanowskiAbstract:Abstract Composite titanium carbide–silver films have been co-deposited by magnetron sputtering-pulsed laser deposition (MSPLD) to study their friction and wear properties in vacuum. The films deposited were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The silver content in the films ranged from 6 to 46 at.%. Structural characterization of the films revealed that Ag had a nano-crystalline Structure when dispersed in the film, but larger crystallites of Ag (∼50–200 nm) also formed on the surface. Films with higher Ag contents showed evidence of higher diffusion rates, leading to a Coarser Structure and greater surface coverage. Pin-on-disk friction tests were performed under vacuum to observe the friction and wear behavior of these films. Friction was lower with higher Ag content, but wear was higher; the optimal Ag concentration was found to be 15%. SEM images from the surface of the films and wear tracks were obtained to understand the morphology of this type of composite ceramic coating, and revealed Ag layers in the wear track elongated in the direction of wear. Based on these results, the significance of silver as a friction-reducing agent in vacuum environments was demonstrated.