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[Display omitted] Herein, we reported the in-situ preparation of manganese ferrite (MnFe 2 O 4) grafted polyaniline (Pani), a magnetic nanocomposite for the potential visible light photocatalytic material as well as electrode material for supercapacitor. The physical characterization of the prepared nanoparticle and nanocomposite was examined with various spectroscopic and microscopic analyses. The peaks observed in the X-ray diffraction study confirm the face-centered cubic phase of MnFe 2 O 4 nanoparticles with a grain size of ∼17.6 nm. The surface morphology analysis revealed the uniform distribution of spherical-like MnFe 2 O 4 nanoparticles on the surface of Pani. The degradation of malachite green (MG) dye under exposure to visible light was investigated using MnFe 2 O 4 /Pani nanocomposite as a photocatalyst. The results exposed the faster degradation of MG dye was accomplished by MnFe 2 O 4 /Pani nanocomposite than MnFe 2 O 4 nanoparticles. The energy storage performance of the MnFe 2 O 4 /Pani nanocomposite was analyzed through cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy analyses. The results exposed that the MnFe 2 O 4 /Pani electrode achieved a capacitance of 287.1 F/g than the MnFe 2 O 4 electrode (94.55 F/g). Further, the respectable capacitance of 96.92% was achieved even after 3000 repetitive cycles stability. Based on the outcomes, the MnFe 2 O 4 /Pani nanocomposite can be suggested as a promising material for both photocatalytic and supercapacitor applications. [ABSTRACT FROM AUTHOR]

• Generalized model for harvesting pressure ripples using the piezoelectric effect is developed. • Force-deflection relationship of the system is determined as a Duffing hardening response. • Expressions for input energy, output electrical energy and energy efficiency are developed. • Good agreement observed between model and experiment for output voltage and power. There is an increasing desire to monitor and control hydraulic systems in an autonomous and battery-free manner. One solution to this challenge is to harvest hydraulic pressure ripples and noise by exploiting the piezoelectric effect. This paper develops a new generalized model of a hydraulic piezoelectric harvester based on a circular edge-clamped flat plate interface with a central piezoelectric stack. Such a model allows the relationships between harvesting performance and structure to be assessed in detail. It is demonstrated that the force-deflection relationship of a circular edge-clamped plate with a central lumped mass follows a cubic hardening Duffing equation. A single degree of freedom (SDOF) lumped-parameter model of the system is established where the nonlinear frequency response resulting from hardening nonlinearities are explored. The input mechanical energy and the output electrical energy both exhibit a quadratic nonlinear relationship with vibration amplitude. The maximum output occurs at the jump-down frequency and the overall energy conversion efficiency of the system is determined. The optimum resistance load for maximum output energy and energy efficiency are obtained as non-dimensional excitation frequency. Experimental validation is performed and good agreement is observed between model results and experimental measurements. The developed model provides important insights into the optimization of power output and response of future hydraulic energy harvesting devices. [ABSTRACT FROM AUTHOR]

Highlights • A new adaptive evolutionary digital filter is proposed for gear fault detection. • The speed and noise cancellation performance of the proposed method are validated. • The proposed method exhibits much faster convergence rate than other methods. Abstract Evolutionary digital filter (EDF) is an adaptive filter that controlled by adaptive algorithm based on the evolutionary strategies: cloning and mating. The adaptive algorithm of EDF exhibits the advantage of avoiding local optimum problems that arise from a multiple-peak performance surface of an adaptive noise cancellation (ANC) system. However, the convergence rate of the classic EDF is limited by inappropriate arrangement of evolutionary strategies and large population of individuals. In this paper, a new method referred to alternately evolutionary digital filter (AEDF) is proposed in order to solve the problem of lower convergence rate of the classic EDF. The basic concept of the proposed method is to alternately apply mating evolutionary strategy to locate the peaks in performance surface quickly and then apply cloning evolutionary strategy to get the global optimum near the peaks accurately. The convergence rate and noise cancellation performance of the proposed method is verified by both simulated signals and experimental signals. The results show that the proposed AEDF-based ANC method can effectively detect the gear tooth spalling faults in noisy environment and exhibits much faster convergence rate compared to previous methods. [ABSTRACT FROM AUTHOR]