Tuhin Subhra Sarkar

A power reaching law-robust nonlinear double integral sliding mode controller is developed in this study to solve the sub-synchronous resonance (SSR) problem in DFIG-based wind farms. The suggested controller is designed using the rotor-side-converter (RSC) dynamic to improve SSR removal. The sliding mode approach is based on a rapid power reaching rule, which ensures that SSR difficulties are eliminated while transient stability performance is improved more quickly. The RSC dynamical model additionally handles external disturbances to illustrate the proposed controller's resiliency. The control law is then obtained using the suggested control technique, and the overall stability is validated using the Lyapunov theorem. A simulation study is performed to demonstrate its performance and compare it with an existing single integral SMC scheme.

The key objective of this paper is to design a control strategy to maintain the DC bus voltage of DC microgrids as well as to ensure efficient power flow within the system. To achieve such an aim a power reaching law-based integral sliding mode controller (PRL-ISMC) is introduced in this paper. The proposed DC microgrid compromises with a solar photovoltaic system connected with a boost converter, a battery energy storage system (BESS) connected with a DC-DC bidirectional converter (DBC), and DC loads. The control law of each component is obtained using the proposed PRL-ISMC scheme. Afterward, the system's stability is proved at every stage using the theory of Lyapunov candidate. Finally, the controller's performance is verified under different operating conditions by simulating on MATLAB / SIMULINK platform. Moreover, to show its usefulness the result also compares with a designed conventional reaching law-ISMC (CRL-ISMC).

Macrophomina phaseolina, a necrotrophic fungal pathogen is known to cause charcoal rot disease in food crops, pulse crops, oil crops and cotton and fibre crops. Necrotrophic fungi survive on dead plant tissue. It is well known that reactive oxygen species (ROS) are produced by the host plant during plant–pathogen interaction. However, it is still unclear how M. phaseolina can overcome the ROS-induced cellular damage. To mimic the invasion of M. phaseolina inside the plant cell wall, we developed solid substrate fermentation where M. phaseolina spore suspension was inoculated on a wheat bran bed and incubated for vegetative growth. To analyse the secretome of M. phaseolina after different day interval, its secretory material was collected and concentrated. Both superoxide dismutase (SOD) and catalase were detected in the secretome by zymogram. The presence of SOD and catalase was further confirmed by liquid chromatography based mass spectrometry. The physicochemical properties of M. phaseolina catalase in terms of stability towards pH, temperature, metal ions and chaotropic agent and inhibitors indicated its fitness at different environmental conditions. Apart from the production of catalase in SSF, the studies on this particular microorganism may also have significance in necrotrophic fungal pathogen and their susceptible host plant interaction.

In this paper an Optical type dual axis tilt sensor is demonstrated for the measurement of surface inclination in the range of ±900. The proposed sensor measured the surface tilt by tracking a pendulum motion in two different axes. Unlike the traditional tilt sensor, the proposed concept used an absolute encoder for sensing the pendulum motion. This newly designed encoding track (named as index and code track) is attached separately with two pendulum blocks. As the encoder tracks are used a gray color coded pattern instead of binary code, hence the pendulum position is encoded as the variant intensity of gray colors. Thus, during the inclination of the sensor, a pair of optical trans-receiver reads the pendulum position by capturing the track information’s as well as transformed it into the variant intensity of lights. Furthermore, a simple signal processing circuit (SPC) has been used for calibrating the light intensity as measured surface inclination. The static behavior of the proposed sensor has been observed in laboratory conditions and found satisfactory performance in the above said measured range.