Synthesis and studies of the zinc acetate (ZA) crystal for dielectric,nano-photonics and electronic applications

Journal of Materials Science: Materials in Electronics - The ZA are finely full-grown by usual slow evaporation solution growing scheme and the single XRD shows the crystal size as well as the...     

A robust image steganography using teaching learning based optimization based edge detection model for smart cities

Recently, Internet becomes a most common medium for transferring critical data and the security of the transmitted data gains maximum priority. Image steganography has been developed as a well-known model of data hiding which verifies the security level of the transferred data. The images offer high capacity, and the occurrence of accessibility over the Internet is more. An effective steganography model is required for achieving better embedding capacity and also maintaining the other variables in an acceptable value. This article introduces a new robust image steganography using Teaching Learning Based Optimization (TLBO) edge detection model. The TBLO is basically a metaheuristic algorithm which is inspired from the teaching and learning procedure in classrooms. The former stage indicates the learning from the teacher and the latter phase represents the interaction among the learners. The experimental validation takes place in a comprehensive way under several views and the outcome pointed out the superior results of the presented model.     

Enhanced performance for photocatalytic hydrogen evolution using MoS2/graphene hybrids

A MoS₂/graphene hybrid (MSG) is synthesized by microwave hydrothermal method. Both of the charge transfer resistance and the photocurrent are tuned in graphene modified MoS₂ by enhancing photocatalytic nature, where the charge transfer resistance significantly decreases from 36,000 Ω–8.49 Ω and the photocurrent promotes from 0.29 mA cm^?2 to 16.47 mA cm^?2. In this article, the result reveals that the appropriate modification of graphene can reach the maximum yield of hydrogen gas. In addition, the appropriate conditions, such as the concentration of 0.32 M formic acid and the MoS₂ photocatalyst with 0.8 wt% graphene (MSG_0.8) dose of 0.013 g L^?1, can complete the outstanding photocatalytic hydrogen evolution, where the hydrogen evolution using MSG_0.8 composite photocatalyst has the maximum yield of 667.2 μmol h^?1 g^?1.     

Rice-net: an efficient artificial fish swarm optimization applied deep convolutional neural network model for identifying the Oryza sativa diseases

Neural Computing and Applications - This research aims to identify rice diseases, namely Leaf blast, Brown spot, Healthy and Hispa. The purpose of this research is to utilize deep convolutional...     

One‐Step Sonochemical Synthesis of Reduced Graphene Oxide/Pt/Sn Hybrid Materials and Their Electrochemical Properties

Low frequency ultrasound (20 kHz) was used for the reduction of graphene oxide (GO), Pt and Sn precursors with simultaneous loading of Pt and Sn monometallic and Pt–Sn bimetallic nanoparticles on the surface of reduced GO (rGO). The physicochemical characterizations of the catalysts were carried out using transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), energy dispersive X‐ray spectroscopy (EDX), and selected area electron diffraction (SAED) techniques. The reduced monometallic and bimetallic nanoparticles were spherical in shape with diameters around 2–6 nm, uniformly embedded on rGO sheets of few layers thickness. The electrocatalytic activities of the synthesized materials were evaluated by cyclic voltammetric studies.     

Synthesis of ZnO and Au tethered ZnO pyramid-like microflower for photocatalytic degradation of orange II

Pyramid-like microflower structured zinc oxide (ZnO) nanoparticles were successfully prepared under hydrothermal processes. Then Au nanoparticles were tethered on ZnO pyramid-like microflower (Au-ZnO) by the reduction of HAuCl₄ in the presence of β-d-glucose as stabilizer. The materials were well characterized by different analytical techniques and they could be potentially utilized for the photocatalytic degradation of orange II in the visible region. SEM images reveal that the ZnO microflowers are well formed at 100 °C and on increasing the temperature ZnO nuclei typically grow in the direction of c-axis alone due to typical increase in the dipole moment along that direction. TEM image shows that gold nanoparticles are tethered on the ZnO surface. A possible mechanism for the formation of ZnO and Au-ZnO microflowers has been also discussed.     

Role of substrate temperature on the growth mechanism and physical properties of spray deposited lead oxide thin films

Thin films of lead oxide were synthesized by cost effective spray pyrolysis technique at different substrate temperatures on glass substrates. Effect of substrate temperature on the growth mechanism and physical properties of the films was investigated. All the films were polycrystalline in nature with tetragonal structure corresponding to α-PbO. The films coated at 225 °C and 275 °C were (1 0 1) oriented, while the films deposited at 325 °C and 375 °C were (0 0 2) oriented. Above 375 °C, the pure tetragonal nature deteriorated and the peaks corresponding to orthorhombic phase were observed. The band gap value was found to be in the range of 2.3 to 2.62 eV. All the films had a resistivity of the order of 10³ ohm-cm. A minimum resistivity of 0.0191 × 10³ ohm-cm was obtained for the film coated at 325 °C. The activation energy increased with increase in substrate temperature.     

Study on antioxidant activity of certain plants in Thailand: Mechanism of antioxidant action of guava leaf extract

The ethanol extracts from 24 samples plant species commonly found in Thailand were investigated and compared on their antioxidant activity by ABTS assay. The ethanol extract from the leaves of guava (Psidium guajava) showed the highest antioxidant capacity with the TEAC value of 4.908 ± 0.050 mM/mg, followed by the fruit peels of rambutan (Nephelium lappaceum) and mangosteen (Garcinia mangostana) with the TEAC values of 3.074 ± 0.003 and 3.001 ± 0.016 mM/mg, respectively. The further investigation of guava leaf extracts from different solvents; n-hexane, ethyl acetate, n-butanol, and methanol, was examined using ABTS and FRAP assays. The total phenolic content was done by Folin–Ciocalteu reaction. The results indicated that the methanol fraction possessed the highest antioxidant activity, followed by the butanol and ethyl acetate fractions, respectively. The hexane fraction showed the lowest antioxidant activity. The results demonstrated that the mechanism of antioxidant action of guava leaf extracts was free radical scavenging and reducing of oxidized intermediates. The phenolic content in guava leaf fraction played a significant role on the antioxidant activity via reducing mechanisms.