Calcium silicate hydrate (CSH) is the major volume phase in the matrix of Portland cement concrete. Total x-ray scattering measurements with synchrotron x rays on synthetic CSH(I) shows nanocrystalline ordering with a particle diameter of 3.5(5) nm, similar to a size-broadened 1.1 nm tobermorite crystal structure. The CSH component in hydrated tricalcium silicate is found to be similar to CSH(I...

A new physical mechanism or mode of plastic deformation in nanocrystalline metals and ceramics is suggested and theoretically described. The mode represents the cooperative grain boundary (GB) sliding and stress-driven GB migration process. It is theoretically revealed that the new deformation mode is more energetically favorable than "pure" GB sliding and enhances the ductility of nanocrystall...

The thermal conductivities of quartz and the siliceous zeolites sodalite, faujasite and zeolite-A have been calculated using molecular dynamics simulations. The predicted thermal conductivities range over one order of magnitude at room temperature, and the quartz values are in reasonable agreement with the available experimental data. Evidence of phonon scattering is found by considering the la...

This paper describes a new strategy to generate nanocrystalline drugs through the precipitation of drug molecules in attoliter nanowells. We controlled the size of arsenic trioxide (ATO) nanocrystals by simply changing the concentration of ATO solution in the nanowells; particles with sizes ranging from 55 to 175 nm were formed. This approach only requires the drugs to be soluble in a solvent a...

AB -type intermetallic compounds were prepared by the melt spinning method. Structure analysis was carried out by X-ray 5 diffractometry, SEM and high resolution electron microscopy. The hydrogen storage capacity was determined by isothermic mass controlled absorption of hydrogen and by electrochemical charge /discharge cycles. A variation of the preparation parameters showed that a nanocrystal...

It is believed that the dynamics of dislocation processes during the deformation of nanocrystalline materials can only be visualized by computational simulations. Here we demonstrate that observations of dislocation processes during the deformation of nanocrystalline Ni with grain sizes as small as 10 nm can be achieved by using a combination of in situ tensile straining and high-resolution tra...

Nanocrystalline partially stabilised zirconia (PSZ) and yttria-fully stabilised zirconia (YSZ) powders were prepared by solution combustion process. Nanocrystalline nature of the powders was confirmed by XRD and TEM. Nanocomposite Ni/PSZ and Ni/YSZ films were electrodeposited from a suspension of nanoparticles in nickel sulfamate solution. The strengthening of the nanocomposite due to nanoparti...

Confirmation of the suggestion of B site zn2+ in nanocrystalline ZnFe204 has heen sought through X-ray diffraction, 5 7 ~ e Miissbauer spectroscopy, magnetic susceptibility and TEM measurements on bulk and nanocrystalline samples prepared by different techniques. Measurements on bulk samples are in agreement with previously reported ones. Samples prepared at low temperature from solutions of sa...

Coexistent amorphous and nanoscale bcc-Mg7Li3 phases were found in slowly quenched alloys of the Mg65–xLixCu25Y10 system containing 3 to 15 at. % Li. The crystallization behavior of these alloys has been studied. The grain size of the nanocrystalline bcc phase which is formed ranges from 2 to 20 nm. The volume fraction of nanocrystalline phases as well as the grain size of the nanocrystals incr...