High aspect ZnO nanorod growth over electrodeposited tubes for photocatalytic degradation of EtBr dye

In this work, vertically grown rod type ZnO nanostructures have been synthesized on metallic nickel tube films fabricated through the cost-effective process of electroforming..

Polishing Technology and Phenomena of the Inner/Outer Surfaces of Small Cup-Type Nickel Tube-Study of Ultraviolet-Ray Aided Machining

Our main purposes were to establish ultraviolet-ray aided machining (here after reffered to as U-RAM) and clarify the chemical and mechanical polishing mechanism. The inner/outer surfaces of small cup-type nickel tube is strongly required to polish, simultaneously. The present study deals with the new development of simultaneous polishing technology and the verify of polishing phenomena that uses a photocatalyst and a cathilon (a luminous dye: Cathilon Brilliant Flavine; hereafter referred to as cathilon) excited by an ultraviolet ray (hereafter referred to as UV). Measurements and observations clarified that TiO2of 0.18-μm grain size polished chemically/mechanically the outer surface using cathilon, and cathilon chemically polished the inner surface of small cup-type nickel tube, simultaneously. Further measurements indicated that the chemical erosion roughened the inner surface, when cathilon increased from 2.5, 5 to 20wt%. An increase of TiO2to 20wt% at 20wt% of cathilon did not result the flatter surface. Aluminum oxide does not provide the polishing ability due to the poor photocatalyst effect compared with TiO2.

Heat Transfer Investigation of Air Flow in Microtubes—Part II: Scale and Axial Conduction Effects

In this paper, the scale effects are specifically addressed by conducting experiments with air flow in different microtubes. Three stainless steel tubes of 962, 308, and 83 μm inner diameter (ID) are investigated for friction factor, and the first two are investigated for heat transfer. Viscous heating effects are studied in the laminar as well as turbulent flow regimes by varying the air flow rate. The axial conduction effects in microtubes are experimentally explored for the first time by comparing the heat transfer in SS304 tube with a 910 μm ID/2005 μm outer diameter nickel tube specifically fabricated using an electrodeposition technique. After carefully accounting for the variable heat losses along the tube length, it is seen that the viscous heating and the axial conduction effects become more important at microscale and the present models are able to predict these effects accurately. It is concluded that neglecting these effects is the main source of discrepancies in the data reported in the earlier literature.

FABRICATION AND CHARACTERIZATION OF Ni-SHEATHED MgB2 SUPERCONDUCTING TAPES

The preparation route for Nickel-sheathed MgB2 tapes has been studied in order to achieve improved transport properties at temperatures above that of liquid helium. Superconducting tapes have been manufactured by the Powder-In-Tube method, that consists in the cold working of a Nickel tube filled by reacted MgB2 powders, and in a final heat treatment carried out in Argon atmosphere. The could working procedure has been tuned in order to achieve the highest degree of MgB2 density, while limiting the formation of sausaging of the superconducting core cross section. The effect of the final heat treatment has been studied both on the superconducting and microstructural properties of the MgB2 tapes. The critical current of the reacted MgB2 tapes has been measured as a function of the magnetic field and of the temperature on short samples as well as on a small pancake coil. Finally, the microstructural and XRD analyses have revealed the clear presence of a MgB2Ni2.5 reaction layer between the Nickel sheath and the Nickel sheath and the MgB2 superconducting core in the reacted samples.