Many second phase additions to YBa₂Cu₃O7-x (YBCO) films, in particular those that self-assemble into aligned nanorod and nanoparticle structures, enhance performance in self and applied fields. Of particular interest for additions are Ba-containing perovskites that are compatible with YBCO. In this report, we discuss the addition of Ba₂YRuO₆ to bulk and thick-film YBCO. Sub-micron, randomly ori...

in this work, ag-cu nanoparticles (with different percentages of copper, 10%, 25%, 50%, 75% cu) were synthesized by wet chemical method. copper(ii) sulfate and silver nitrate were taken as metal precursors, ascorbic acid as reducing agent and anhydride maleic (ma) as a modifier. the prepared nanoparticles were characterized by means of x-ray diffraction (xrd) technique and scanning electron mic...

In isolated bimetallic nanoscale systems the limit amount of matter and surface-induced size effects can change the thermodynamics of first-order phase transformation. In this paper we present theoretical modification of Gibbs free energy concept describing first-order phase transformation of binary alloyed nanoparticles taking into account size effects as well as depletion and hysteresis effec...

In this report, we present a general method for a continuous gas-phase synthesis of size-selected metal/multi layer graphene (MLG) core shell nanoparticles having a narrow size distribution of metal core and MLG shell for direct deposition onto any desired substrate kept under clean vacuum conditions. Evolution of MLG signature is clearly observed as the metal-carbon agglomerates get transforme...

This paper investigates an analytical analysis for the flow and heat transfer in a viscous fluid over a nonlinear stretching sheet. The governing partial differential equations are transformed into coupled nonlinear differential equations by introducing a similarity transformation. The asymptotic analytical solutions are obtained by using differential transform method-basic functions (DTM-BF). ...

The aim of the present paper is to study the flow of nanofluid and heat transfer characteristics between two horizontal plates in a rotating system. The lower plate is a stretching sheet and the upper one is a solid porous plate. Copper Cu as nanoparticle and water as its base fluid have been considered. The governing partial differential equations with the corresponding boundary conditions are...

In this paper, Homotopy perturbation method (HPM) has been applied to investigate the effect of magnetic field on Cu-water nanofluid flow in non-parallel walls. The validity of HPM solutions were verified by comparing with numerical results obtained using a fourth order Runge–Kutta method. Effects of active parameters on flow have been presented graphically. The results show that velocity i...

The hot-wire method is applied in this paper to probe the thermal conductivity (TC) of Cu and Ni nanoparticle packed beds (NPBs). A different decrease tendency of TC versus porosity than that currently known is discovered. The relationship between the porosity and nanostructure is investigated to explain this unusual phenomenon. It is found that the porosity dominates the TC of the NPB in large...

ZnO-supported palladium-based catalysts have been shown in recent years to be both active and selective towards the steam reforming of methanol, although they are still considered to be less active than traditional copper-based catalysts. The activity of PdZn catalysts can be significantly improved by supporting them on alumina. Here we show that the Pd/ZnO/Al2O3 catalysts have better long-term...

We report the structural, morphological, and electrochemical properties of polypyrrole (PPy), copper doped PPy (Cu/PPy), multi-walled carbon nanotubes (Cu/PPy/MWCTs) prepared by oxidative polymerization technique. The incorporation Cu in form nanoparticles composites was confirmed from XRD data. granular morphology observed FESEM micrograph. However, size grains decreased with nanoparticle inse...