Bharathiar University

About: Bharathiar University is a education organization based out in Coimbatore, Tamil Nadu, India. It is known for research contribution in the topics: Thin film & Adsorption. The organization has 5812 authors who have published 8628 publications receiving 143934 citations. The organization is also known as: BU.

Synchronization of reaction–diffusion neural networks with time-varying delays via stochastic sampled-data controller

Abstract: This paper discusses the synchronization problem for a class of reaction–diffusion neural networks with Dirichlet boundary conditions. Unlike other studies, a sampled-data controller with stochastic sampling is designed in order to synchronize the concerned neural networks with reaction–diffusion terms and time-varying delays, where $$m$$ sampling periods are considered whose occurrence probabilities are given constants and satisfy the Bernoulli distribution. A novel discontinuous Lyapunov–Krasovskii functional with triple integral terms is introduced based on the extended Wirtinger’s inequality. Using Jensen’s inequality and reciprocally convex technique in deriving the upper bound for the derivative of the Lyapunov–Krasovskii functional, some new synchronization criteria are obtained in terms of linear matrix inequalities. Numerical examples are provided in order to show the effectiveness of the proposed theoretical results.

Photocatalytic degradation of organic dyes under visible light irradiation by floral-like LaFeO3 nanostructures comprised of nanosheet petals

Abstract: A facile and cost-effective surfactant assisted hydrothermal technique was used to prepare functional floral-like LaFeO3 nanostructures comprised of nanosheets via a self-assembly process. Scanning electron microscopy images revealed the floral structure of LaFeO3 comprising of nanosheet petals. The petals of ∼15 nm thickness and ∼70–80 nm length observed from transmission electron microscopy self-assembled to form floral structures. X-ray powder diffraction, Fourier-transform infrared spectroscopy and thermal analysis techniques were utilized to determine the structural information and thermal stability. The structural characterization revealed the orthorhombic phase of the prepared LaFeO3 product with high purity even at a high temperature of 800 °C. The growth mechanism of LaFeO3 floral nanostructures has been proposed and the band gap energy was estimated to be 2.10 eV using UV-Vis diffuse reflectance spectroscopy. The Brunauer–Emmett–Teller specific surface area was found to be 90.25 m2 g−1. The visible light photocatalytic activities of LaFeO3 floral nanostructures exhibited higher photocatalytic efficiency compared to the bulk LaFeO3 samples for the degradation of rhodamine B (RhB) and methylene blue (MB). The degradation of MB was higher than RhB. The photocatalytic mechanism for the degradation of organic dye has also been proposed.

Sampled-Data H ∞ Synchronization of Chaotic Lur'e Systems with Time Delay

Abstract: This paper deals with the problem of robust $$H_{\infty }$$H? synchronization of chaotic Lur'e systems with time-varying delays via sampled-data control. In order to make full use of the information about sampling intervals, nonlinear functions and time-varying delays, an improved Lyapunov---Krasovskii (L---K) functional is introduced. Based on reciprocal convex combination technique, sufficient conditions are derived in terms of linear matrix inequalities (LMIs) to ensure the asymptotic synchronization of the considered Lur'e system with a guaranteed $$H_{\infty }$$H? performance. By solving the obtained LMIs, the required sampled-data control gain matrix is obtained, which assures the asymptotic stability of the error system and reduces the effect of external disturbance according to $$H_{\infty }$$H? norm. Finally, the effectiveness and less conservatism of the proposed method are verified through numerical simulations of the Chua's circuit and neural networks.