The electroosmotic flow of a micropolar fluid in a microchannel bounded by two parallel porous plates undergoing periodic vibration is studied. The equations for conservation of linear and angular momentums and Gauss...The electroosmotic flow of a micropolar fluid in a microchannel bounded by two parallel porous plates undergoing periodic vibration is studied. The equations for conservation of linear and angular momentums and Gauss's law of charge distribution are solved within the framework of the Debye-Hückel approximation. The fluid velocity and microrotation are assumed to depend linearly on the Reynolds number. The study shows that the amplitude of microrotation is highly sensitive to the changes in the magnitude of the suction velocity and the width of the microchannel. An increase in the micropolar parameter gives rise to a decrease in the amplitude of microrotation. Numerical estimates reveal that the microrotation of the suspended microelements in blood also plays an important role in controlling the electro-osmotically actuated flow dynamics in microbio-fluidic devices.展开更多
Zinc oxide (ZnO) thin films were grown on silicon substrate by RF (radio frequency) magnetron sputtering.Surface topography of these films exhibited a nanostructured granular appearance with the size of individual...Zinc oxide (ZnO) thin films were grown on silicon substrate by RF (radio frequency) magnetron sputtering.Surface topography of these films exhibited a nanostructured granular appearance with the size of individual grains between 50 to 100 nm.Corresponding cross-sectional electron micrographs revealed columnar grains in the form of aggregated nanorods/wires with length of about 500 nm,similar to the thickness of these thin films of ZnO nucleated and grown vertically on the silicon substrate.High resolution lattice scale imaging using high resolution transmission electron microscope (HRTEM) elucidated the single crystalline 1010 planes of hexagonal-ZnO constituting the columnar grains with the individual nanorod diameter between 3 and 4 nm.The photoluminescence measurements showed the prominent emission peak at around 460 nm for the blue band,normally attributed to intrinsic defects in particular interstitial zinc (Zn).These films were further characterized by X-ray diffraction (XRD),Fourier transform infrared spectroscopy (FTIR),Raman spectroscopy and electron paramagnetic resonance (EPR) to evaluate various aspects on preferred growth orientations,band structures and vibrational modes originated in such fascinating nano-grained thin films of ZnO.The present investigations inferred that these films are advantageous in various potential applications for fabricating nano-scaled devices.展开更多
文摘The electroosmotic flow of a micropolar fluid in a microchannel bounded by two parallel porous plates undergoing periodic vibration is studied. The equations for conservation of linear and angular momentums and Gauss's law of charge distribution are solved within the framework of the Debye-Hückel approximation. The fluid velocity and microrotation are assumed to depend linearly on the Reynolds number. The study shows that the amplitude of microrotation is highly sensitive to the changes in the magnitude of the suction velocity and the width of the microchannel. An increase in the micropolar parameter gives rise to a decrease in the amplitude of microrotation. Numerical estimates reveal that the microrotation of the suspended microelements in blood also plays an important role in controlling the electro-osmotically actuated flow dynamics in microbio-fluidic devices.
文摘Zinc oxide (ZnO) thin films were grown on silicon substrate by RF (radio frequency) magnetron sputtering.Surface topography of these films exhibited a nanostructured granular appearance with the size of individual grains between 50 to 100 nm.Corresponding cross-sectional electron micrographs revealed columnar grains in the form of aggregated nanorods/wires with length of about 500 nm,similar to the thickness of these thin films of ZnO nucleated and grown vertically on the silicon substrate.High resolution lattice scale imaging using high resolution transmission electron microscope (HRTEM) elucidated the single crystalline 1010 planes of hexagonal-ZnO constituting the columnar grains with the individual nanorod diameter between 3 and 4 nm.The photoluminescence measurements showed the prominent emission peak at around 460 nm for the blue band,normally attributed to intrinsic defects in particular interstitial zinc (Zn).These films were further characterized by X-ray diffraction (XRD),Fourier transform infrared spectroscopy (FTIR),Raman spectroscopy and electron paramagnetic resonance (EPR) to evaluate various aspects on preferred growth orientations,band structures and vibrational modes originated in such fascinating nano-grained thin films of ZnO.The present investigations inferred that these films are advantageous in various potential applications for fabricating nano-scaled devices.