The corrosion resistance of nanopowders of borides and carbides of metals of IV-VIB groups, as well as of silicon carbide, was studied in the standard nickeling electrolytes. As objects of study, nanopowders with the content of the main phase 91.8-97.6% and with the average particle size 32-78 nm were used. Their corrosion resistance was evaluated depending on the acidity of the electrolyte, te...

We fabricate nanosized superconducting YBa(2)Cu(3)O(7-δ) (Y-123) and nonsuperconducting Y(2)BaCuO(5) (Y-211) powders using carbon nanotubes as template. The mean particle size of Y-123 and Y-211 is 12 and 30 nm, respectively. The superconducting transition temperature of the Y-123 nanopowder is 90.9 K, similar to that of commercial, micrometer-scale powders fabricated by conventional processing...

Nanoscale hydroxyapatite based ceramics are a relatively new form of materials that are currently being investigated for a number of potential biomedical applications. This study reports on a straightforward wet chemical method that uses calcium hydroxide and phosphoric acid as precursors. After chemical synthesis a conventional thermal treatment was used to produce an ultrafine hydroxyapatite ...

A novel flexible room temperature ethanol gas sensor was fabricated and demonstrated in this paper. The polyimide (PI) substrate-based sensor was formed by depositing a mixture of SnO2 nanopowder and poly-diallyldimethylammonium chloride (PDDAC) on as-patterned interdigitated electrodes. PDDAC acted both as the binder, promoting the adhesion between SnO2 and the flexible PI substrate, and the d...

The alpha and gamma phases of aluminum oxide were fingerprinted using electron energy-loss spectroscopy (EELS) with an energy resolution of 0.4 eV. Electron diffraction and powder x-ray diffraction were used to determine the phase of micron and nanopowder alumina samples. The results from indexing peak and ring diffraction patterns proved to be ambiguous and were resolved by comparing EELS spec...

The nature of observed growth of solid carbon on palladium from ethylene-hydrogen mixtures is consistent with the supposition that the primary source of carbon for growth is homogeneously generated radicals. Evidence includes the lack of growth in the absence of a reacting mixture, sharp maxima as a function of temperature, and dramatic differences in temperature of growth as a function of mixt...

(Bi0.5Na0.5)TiO3 doped with 8 mol % BaTiO3 powder (BNT-BT0.08), prepared by sol-gel method was compacted and sintered by Spark Plasma Sintering (SPS) process. The influence of SPS temperature on the densification of BNT-BT0.08 ceramic was investigated. Starting from sol-gel nanopowder of BNT-BT containing 8 mol % BaTiO3 with an average particles size of about 30 nm, were obtained ceramics with ...

The quenching of the photoluminescence of Si nanopowder grown by plasma-enhanced chemical vapor deposition due to pressure was measured for various gases ~ H2, O2, N2, He, Ne, Ar, and Kr! and at different temperatures. The characteristic pressure, P0, of the general dependence I(P) 5 I0 exp( 2 P/P0) is gas and temperature dependent. However, when the number of gas collisions is taken as the var...

Enhanced thermal conductivity of nanofluids has proven importance in enhancing heat transfer for many application. In this study, graphite nanopowder dispersed water at different temperatures was studied experimentally. Stable concentrations (0.2 vol%, 0.5 0.8 1 vol% and 1.5 vol%) are prepared using ultrasonic cleaner by sonicating 3 hour. Thermal measured from temperature 25 to 55 ºC with an i...