In this research, effect of nanoparticles dimeter on free convection of aluminum oxide-water was investigated in a cavity by single phase and two phase models. The range of Rayleigh number is considered 105-107 in volume fractions of 0.01 to 0.03 for nanoparticles with various diameters (25, 33, 50 and 100 nm). Given that the two phase nature of nanofluids, necessity of modeling by this method ...

objective(s): a large ratio of surface to volume of nanoparticles in comparison with bulk ones, will increase the cell penetration and therefore their toxicity. materials and methods: chemical precipitation method was used in order to synthesis of zns:ag quantum dots. their physical properties and characteristics were assessed by x-ray diffraction, ultra violet-visible spectrophotometer, transm...

A means for synthesizing paramagnetic nanoparticles composed of an Au–Fe alloy is described using pulsed laser deposition (PLD) of the alloy into a mesoporous alumina membrane template. Nanoparticles 46 ± 13 nm in diameter and composed of a 17% Fe alloy have been created by depositing a 35% Fe alloy into a template with 65 nm diameter pores. These paramagnetic nanoparticles had a saturation mag...

Tetragonal Sn nanoparticles of ∼15 nm diameter are produced in Al2O3 by direct Sn implantation at room temperature. After thermal annealing at 1000 ◦C in oxygen, the implantation-induced amorphous region recrystallized and the Sn nanoparticles turned into SnO2 nanoparticles with an average diameter of ∼30 nm as revealed by transmission electron microscopy. While no absorption and photoluminesce...

The present paper focuses on problem of mixed convection fluid flow and heat transfer of Al2O3-water nanofluid with temperature and nanoparticles concentration dependent thermal conductivity and effective viscosity inside Lid-driven cavity having a hot rectangular obstacle. The governing equations are discretized using the finite volume method while the SIMPLER algorithm is employed to couple v...

nanoparticles of the zno and tio2 were synthesized and the physicochemical properties of the compounds were characterized by ir, x-ray diffraction (xrd), scanning electron microscopy (sem) and transmission electron microscopy (tem). the xrd patterns of the zno and tio2 nanoparticles could be indexed to hexagonal and rutile phase, respectively. aggregated nanoparticles of zno and tio2 with spher...

template synthesis is a powerful method for the preparation of nanoscale materials with specific size and shape. cadmium oxide (cdo) nanoparticles were synthesized by using sodium dodecyl sulfate (sds), cd(oac)2.2h2o and sodium hydroxide as starting materials. the sample was characterized by x-ray diffraction (xrd), scanning electron microscopy (sem). the xrd pattern proves that the final produ...

A numerical investigation has been carried out applying single phase approach on turbulent forced convection flow of water based Al2O3 and TiO2 nanofluids flowing through a horizontal circular pipe under uniform heat flux boundary condition applied to the wall. The effect of volume concentrations, Brownian motion and size diameter of nanoparticles on flow and heat transfer have been examined fo...

Changes in the shape and size of Co, Pt and Au nanoparticles induced by swift heavy-ion irradiation (SHII) have been characterized using a combination of transmission electron microscopy, small-angle x-ray scattering and x-ray absorption near-edge structure. Elemental nanoparticles of diameters 2-15 nm were first formed in amorphous SiO 2 by ion implantation and thermal annealing and then irrad...

In aqueous conditions, we monitor in real time the ionic current through individual artificial nanopores under an applied potential. The nanopores are drilled through Si 3 N 4 membranes 30 and 50 nm thick to diameters rangingfrom 2.5 to 6.5 nm. After chemical surface hydroxylation, and addition of bipyridyl, we are able to observe alterations of the ionic current recording when negatively charg...