This paper proposes a robust nonlinear controller for a proton exchange membrane fuel cell coupled with a DC-DC boost converter. The key feature is to maintain the desired reference output voltage despite significant disturbances while improving transient stability. In order to do this, a nonlinear robust integral terminal sliding mode controller (ITSMC) is proposed, along with the derivation of the control law, explanation of the reachability analysis, and stability condition. An adapted integral sliding surface is used to capture the dynamics caused by variations in the input voltage and loads. In addition, a modified reaching law is proposed to guarantee the finite time convergence while reducing the chattering. Afterward, the Lyapunov control theory is employed to evaluate the DC-DC boost converter’s large-signal stability while guaranteeing the resilience of the proposed controller. Finally, the applicability of the proposed controller is evaluated through comprehensive analyses on both the simulation platform and the real-time processor-in-loop (PIL) platform under various operating conditions, such as the variation in load resistance, reference output voltage, etc. All of the results, when compared to an existing integral terminal sliding mode controller, indicate quick reference tracking capability with reduced overshoots and robustness against disturbances.

A grapefruit-shape hollow-core liquid infiltrated photonic crystal fiber (LI-PCF) is proposed and evaluated to identify the percentage of kerosene in adulterated petrol. The proposed hollow-fiber sensor is designed with Cyclo Olefin Polymer (Zeonex) and likely to be filled with different samples of petrol which is adulated by the kerosene up to 100%. Considering the electromagnetic radiation in THz band, the sensing properties are thoroughly investigated by adopting finite element method (FEM) based COMSOL Multiphysics software. However, the proposed sensor offers a very high relative sensitivity (RS) of 97.27% and confinement loss (CL) less than 10⁻¹⁰ dB/m, and total loss under 0.07 dB/cm, at 2 THz operating frequency. Besides that, the sensor also possesses a low effective material loss (EML), high numerical aperture (NA), and large Marcuse spot size (MSS). The sensor structure is fabrication feasible through existing fabrication methodologies consequently making this petrol adulteration sensor a propitious aspirant for real-life applications of petrol adulteration measurements in commercial and industrial sensing.

We propose an electric field tunable nematic liquid crystal (NLC) infiltrated single-hole hollow fiber sensor for voltage measurement. Due to only an air hole, the proposed sensor got a straightforward structure, and the liquid-filling process will be uncomplicated. The addition of the gold wire successfully incorporated the surface plasmon resonance (SPR) phenomenon as a sensing methodology in the proposed sensor. Besides that, the use of metal wire instead of the metal film will reduce the complicacy associated with the acquisition of uniform film thickness. The sensor characterization and performance evaluation have been done using the finite element method (FEM) for a wide voltage range from 200V to 400V. The sensor exhibits wavelength sensitivity (WS) and linearity as high as 5 nm/V and 0.9935, respectively. In addition, maximum amplitude sensitivity (AS) and wavelength resolution (R) is attained of −353.46 RIU⁻¹ and 0.02V, respectively. Due to its excellent performance with a wide sensing range, and a simple and compact structure, the proposed sensor can be used for voltage measurement in a sophisticated place.

In this paper gate on source tunnel field effect transistor structure has been considered which is an unconventional one. In analytical derivation of current, impact of field-induced quantum confinement under the gate has been successfully incorporated which has resulted in a significant modification in tunneling current as compared to semiclassical models. The model has also used a more accurate potential term at the Si/HfO₂(Source/Gate oxide) interface in the source through some rigorous calculation of electron concentration in both strong and weak inversion regimes. Exponential integral function is introduced for the derivation of the analytical formula of the band to band tunneling current. The obtained analytical expressions are compared with results from the simulator and good agreement is found.