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Microstructural Study (microstructural + study)
Selected AbstractsMicrostructural Study of Mn and Si Co-substituted Hydroxyapatite Thin Films Produced by a Sol,Gel MethodADVANCED ENGINEERING MATERIALS, Issue 7 2009Aligül Büyükaksoy Microstructural changes in sol,gel derived hydroxyapatite thin films associated with Mn and Si co-substitution are investigated. The apatite-forming ability of fabricated thin films in simulated body fluid are found to be affected by changes in the crystallinity and formation of a more dissolvable calcium phosphate phase. [source] Experimental dehydration kinetics of serpentinite using pore volumometryJOURNAL OF METAMORPHIC GEOLOGY, Issue 4 2007S. LLANA-FÚNEZ Abstract A series of dehydration experiments was carried out on both intact rock and cold-pressed powdered samples of serpentinite at temperatures in the range 535,610 °C, 100,170 °C above the onset of the breakdown temperature of 435 °C. Pore water pressures near 120 MPa were servo-controlled using a pore volumometer that also allowed dehydration reaction progress to be monitored through measurement of the amount of evolved water. Effective hydrostatic confining pressures were varied between 0 and 113 MPa. The reaction rate of intact specimens of initially near-zero porosity was constant up to 50,80% reaction progress at any given temperature, but decreased progressively as transformation approached completion. Water expulsion rates were not substantially affected by elevation of effective pressures that remained insufficient to cause major pore collapse. An Arrhenius relation links reaction rate to temperature with an activation enthalpy of 429 ± 201 and 521 ± 52 kJ mol,1 for powdered and intact specimens, respectively. Microstructural study of intact specimens showed extensive nucleation beginning at pre-existing cracks, veins and grain boundaries, and progressing into the interior of the lizardite grains. Extrapolation of these data towards equilibrium temperature provides an upper bound on the kinetics of this reaction in nature. [source] Microstructural study of micron-sized craters simulating Stardust impacts in aluminum 1100 targetsMETEORITICS & PLANETARY SCIENCE, Issue 2 2006Hugues Leroux First, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to study the morphology of the impact craters and the bulk composition of the residues left by soda-lime glass impactors. A more detailed structural and compositional study of impactor remnants was then performed using transmission electron microscopy (TEM), EDS, and electron diffraction methods. The TEM samples were prepared by focused ion beam (FIB) methods. This technique proved to be especially valuable in studying impact crater residues and impact crater morphology. Finally, we also showed that infrared microscopy (IR) can be a quick and reliable tool for such investigations. The combination of all of these tools enables a complete microscopic characterization of the craters. [source] Microstructure,magnetic properties relationships in nanocrystalline Nd,Fe,Co,Ge,B annealed ribbonsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 2 2006R. Gholamipour Abstract In this work, the effects of Ge addition on the microstructure and magnetic properties of some rapidly quenched Nd13.5Fe(74.9,z )Co5.5Gez B6 alloys with z = 0.0, 0.18, 0.36, 0.54, 0.72 and 0.9 prepared by a rapid solidification method were studied. For the first time, detailed microstructural study of nanometer size grain boundaries enriched with very small amount of Ge as well as Nd was carried out using 3 Dimensional Atom Probe (3DAP) technique. The magnitudes of Br and (BH )max were seen to increase for the samples substituted with up to 0.36 at% Ge in spite of the fact that Ge is a non-magnetic atom. This was related to the observed change of Co concenteration in matrix phase. However, the magnetic properties deteriorated for the samples with Ge addition beyond 0.36 at%. The observed magnetic properties are discussed in relation with the observed microstructural changes monitored by 3DAP and TEM techniques. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] PROVENANCE OF MARBLES FROM NAXOS BASED ON MICROSTRUCTURAL AND GEOCHEMICAL CHARACTERIZATIONARCHAEOMETRY, Issue 2 2010A. EBERT A detailed quantitative microstructural study coupled with cathodoluminescence and geochemical analyses on marbles from Naxos demonstrates that the analysis of microstructures is the most sensitive method to define the origin of marbles within, and between, different regions. Microstructure examination can only be used as an accurate provenance tool if a correction for the second-phase content is considered. If second phases are not considered, a large spread of different microstructures occurs within sample sites, making a separation between neighbouring outcrops difficult or impossible. Moreover, this study shows that the origin of a marble is defined more precisely if the microstructural observations are coupled with cathodoluminescence data. [source] | ||||||||||