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This study focuses on the synthesis, characterization, and assessment of the synergistic effect of 2,2,6,6, tetramethylpiperidine-N-oxyl (TEMPO)-coated titanium dioxide nanorods (TiO 2 NRs) for photodynamic therapy (PDT). Firstly, TiO 2 NRs were synthesized by the sol–gel technique. Then, TEMPO was grafted on TiO 2 NRs with the aid of oxoammonium salts. Next, the final product was characterized by applying manifold characterization techniques. X-ray diffraction was used to perform crystallographic analysis; transmission electron microscopy (TEM) was used to conduct morphological analysis; Fourier transform infrared (FTIR) and Raman spectra were recorded to perform molecular fingerprint analysis. Furthermore, experimental and empirical modeling was performed to confirm the suitability of as-prepared samples for PDT applications using (MCF-7 cell line) Human Breast Cancer cell line. Our results revealed that bare TiO 2 NRs did not exhibit a significant response for therapeutic applications compared to TEMPO-conjugated TiO 2 NRs in the dark; however, they exhibited a prominent response for the PDT application under UV-A light. Therefore, it is concluded that TEMPO-coated TiO 2 NRs shows the synergistic response for therapeutic approach under UV-A light irradiation. In addition, TEMPO capped TiO2 nanorods not only overcome the multidrug resistance (MDR) hindrance but also exhibit excellent response for cancer cell (MCF-7 cells) treatment only under UV light irradiation via PDT. It is expected that the proposed TiO 2 NRs + TEMPO nanocomposite, which is suitable for PDT treatment, may be essential for photodynamic therapy. [ABSTRACT FROM AUTHOR]

Abstract: Zinc oxide semiconductor is a promising material for various optoelectronic applications such as visible light and UV detectors. The photoresponse and electrical characterization of the photodiode based nanofibers n-ZnO and p-Si semiconductors have been investigated. The Al/p-Si/n-ZnO/Al diode shows a clear rectifying behavior with a rectification ratio of 2.90×104 at ±4V. The diode exhibits a photoconducting behavior with a ratio I on/off of 60. The photoconducting mechanism of the diode is controlled by the presence of exponential distribution of impurity levels in the forbidden band of ZnO. The obtained results indicate that the Al/p-Si/n-ZnO/Al diode can be used as photodiode in optoelectronic applications. [Copyright &y& Elsevier]

Abstract: The pentacene thin film transistor was fabricated on a SiO2/Si substrate by thermal evaporated method at room temperature. Electrical characteristics of the pentacene transistor subjected to a UV light excitation at a wavelength of 365nm were analyzed. A significant increase in the drain current of the pentacene thin film transistor under a UV excitation of 365nm is observed with a maximum photosensitivity of 4.51 in the depletion regime. It is concluded that the pentacene thin film transistor can be used in UV photo-detecting devices. [ABSTRACT FROM AUTHOR]

In this paper, a generalized Newtonian nanofluid in a bio-microfluidics channel due to combined effects of peristalsis and external applied electric field in the presence of thermal radiation and Joule heating is considered. The Poisson and Nernst-Planck equations are taken into account. The obtained non-linear coupled ordinary differential equations are simulated numerically. The impacts of several parameters under the applied electric field on velocity, temperature, concentration, trapping isothermal lines, Nusselt, and Sherwood numbers are presented graphically. It is observed that the number of isothermal lines increases with the electro-osmotic parameter thermophoresis parameter and Brownian motion parameter while perter out with thermal radiation. The results are helpful to design the micro pumps/chips used in medical engineering and improved the thermal efficiency and the durability of microchip cooling devices. [ABSTRACT FROM AUTHOR]

Oblique stagnation point flow of incompressible Maxwell nanofluid past a stretching cylinder with active and passive controlled nanoparticles concentration condition is discussed numerically. The suitable coordinate decomposition reduce the governing boundary layer equations into the system of nonlinear ordinary differential equations which are approximated by Keller box procedure for several values of pertinent parameters. The Numerical results are compared and validated with existing ones as particular cases and found to be an excellent agreement. Velocity profile and lines of flow are sketched to discuss the Obliqueness of the flow. The temperature and concentration profiles drawn to illustrate the influence of involved parameters also variations in local Nusselt and Sherwood numbers are presented through tabular data. It is observed that the behavior of tangential velocity for the viscoelastic fluid and concentration of nanoparticles against thermophoresis diffusion over the cylinder are quite opposite when compared with the results over flat sheet. The temperature distribution and concentration of nanoparticles decreases with elasticity of the fluid. [ABSTRACT FROM AUTHOR]

This study elaborates on the flow of viscoelastic nanofluid consisting of gyrotactic microorganism over a rotating stretching disk along with convective boundary and zero mass flux conditions. Using the similarity transformations the nonlinear coupled partial differential equations regulating the present problem are converted into a set of ordinary differential equations which are approximated numerically by the Keller Box method. The numerically obtained results are verified with the available existing literature for particular values of the involved parameters which are limiting cases of the present analysis. Variation of heat and mass transfer and density numbers are presented graphically and the influence of various parameters on both radial and azimuthal velocities, temperature, concentration, and density of motile-microorganisms for convective and non-convective surfaces is shown through various plots and discussed. [ABSTRACT FROM AUTHOR]

Abstract A new solar-sensitive zinc oxide doped-amorphous carbon diode was fabricated using the electrochemical deposition technique. The current-voltage characteristics of the fabricated Al/ZnO-a:C/p-Si/Al diode were investigated under dark and various lighting intensities using both I-V and C-V methods. The fabricated diode was characterized by XRD, SEM-EDS, FTIR and XPS analysis. Through the analysis, it was determined that the photocurrents increased with increasing intensity of incident light. The capacitance-voltage (C-V) characteristics revealed that the capacitance of the diode depended on voltage, frequency and illumination, indicating the existence of a continuous distribution of interface states. It was found that the capacitance changed drastically with changing frequency and separation was observed in different frequencies, as identified in the reverse bias region. The ideality factor obtained was found to be higher than unity, with the average barrier height and ideality factor of the diode were found to be 0.528 ± 0.0069 eV and 5.24 ± 0.39, respectively. The newly fabricated ZnO-doped amorphous carbon (Al/ZnO-a:C/p-Si/Al) photodiode exhibited good solar sensitivity. The overall results indicated that the fabricated Al/ZnO-a:C/p-Si can be used as a solar sensitive diode in optoelectronic device applications as an alternative to graphene-based materials. [ABSTRACT FROM AUTHOR]

The present study particularizes the effects of nonlinear thermal radiation and the novel accepts of activation energy in the axisymmetric rotational stagnation point flow of hybrid fluid. Thermophysical properties of water and CWCNT / MWCNT are used for base fluid and nanoparticles respectively. The modeled partial differential equations are reduces to system of ordinary differential equations. The resulting equations are integrated numerically and the impact of involved parameters on velocity, temperature and nanoparticle concentration presented graphically. The tabular values for local Nusselt numbers in case of linear and nonlinear thermal radiation and the Sherwood number with and without activation energy are documented. It is observed that concentration of nanoparticles reduces with activation energy and increasing the solid volume fraction of SWCNT as well as MWCNT nanoparticles. Moreover the axial velocity increases while secondary velocity decreases by increasing the rotation parameter. [ABSTRACT FROM AUTHOR]

We developed a composite consisting of mesoporous ZrO 2 thin films supporting catalytically active gold nanoparticles (Au NPs) for the oxidative removal of carbon monoxide (CO). At first, highly ordered mesoporous ZrO 2 (m-ZrO 2) thin films are prepared by sol-gel-based spin-coating process followed by a controlled thermal treatment process in air. Then, Au NPs are successfully dispersed and deposited over the entire framework of mesoporous ZrO 2 thin films to form Au/m-ZrO 2 films. The specific surface area and crystallinity of the m-ZrO 2 thin films as well as the periodicity of the mesoporous framework can be controlled by adjusting the calcination temperature and the synthetic parameters. The catalytic efficiency of the optimized Au/m-ZrO 2 composite film toward CO conversion reaches 94% of circulation time, and is well-retained even after 1 h (∼88%). Image 1 • Oxidative removal of carbon monoxide (CO) at room temperature is introduced. • Ordered mesoporous ZrO 2 thin films are prepared by a sol-gel method. • Au nanoparticles (NPs) are dispersed over the entire framework of mesoporous ZrO 2. • The catalytic efficiency of the mesoporous ZrO 2 film with Au NPs reaches 94.0%. • Indoor air purification devices can be fabricated using our catalysts. [ABSTRACT FROM AUTHOR]