Shantanu Das

Bio: Shantanu Das is an academic researcher from Bhabha Atomic Research Centre. The author has contributed to research in topics: Fractional calculus & PID controller. The author has an hindex of 24, co-authored 152 publications receiving 2925 citations. Previous affiliations of Shantanu Das include University of Chicago & Jadavpur University.

Observation of Fractional Calculus in Physical System Description

Abstract: Fractional calculus allows a more compact representation and problem solution for some spatially distributed systems. Spatially distributed system representation allows a better understanding of the fractional calculus. The idea of fractional integrals and derivatives has been known since the development of regular calculus. Although not well known to most engineers, prominent mathematicians as well as scientists of the operational calculus have considered the fractional calculus. Unfortunately many of the results in the fractional calculus are given in language of advanced analysis and are not readily accessible to the general engineering and science community. Many systems are known to display fractional order dynamics. Probably the first physical system to be widely recognized as one demonstrating fractional behavior is the semi-infinite lossy (RC) transmission line. The current into the line is equal to the half-derivative of the applied voltage.

Modeling and control of four quadrant chopper fed DC series motor using two-degree of freedom digital fractional order PID controller

Abstract: The aim of the paper is to implement two degree of freedom digital fractional order proportional-integral-derivative (2-DOF FOPID) controller for speed control of DC series motor. Speed control is achieved by pulse width modulated control method through four quadrant chopper circuit. For realization of digital fractional order controller in integer order sense, pole-zero interlacing method is used. The controller parameters are tuned by using improved dynamic particle swarm optimization (IDPSO) technique. The effectiveness of proposed control scheme is simulated using FPGA (field programmable gate array)-in-loop wizard of MATLAB/Simulink. The performance comparison shows improvement with proposed controller as compared to integer counterpart.

Denoising SPND signal by discrete wavelet analysis for efficient power feedback in regulating system of PHWRs under noisy environment

Abstract: This paper aims to denoise a neutron power sensor data which is the output of Self Powered Neutron Detector (SPND) in each of the Liquid Zone Compartments (LZC) in a nuclear reactor core. Noisy data measured over long period is analyzed with different types of wavelets by one dimensional Discrete Wavelet Transform (DWT) technique to investigate the local feature of the measured signal by selecting proper basis wavelet to feedback the processed signal for global reactor power control and safety purposes. Denoising has also been carried out, considering the SPND signal, corrupted with fractional order (FO) noise. A relative Maximum Absolute Error (MAE) based analysis, adopted in this paper is done to precisely compare the wavelet performances in integer and fractional order type noisy SPND signal.

Physics of electrostatic resonance with negative permittivity and imaginary index of refraction for illuminated plasmoid in the experimental set up for microwave near field applicator

Abstract: In this paper electrodynamics of plasmoid lighting is explained, which we are generating via creation of localized hot spot by application of microwave energy. The microwave radiation is applied via co-axial applicator, the monopole antenna; and the ‘near field’ of the radiation causes local hot spots and thereby thermal runaway causing ejection of small particles from the base substrate. These particles interact with the Electromagnetic field, and due to electrostatic resonances occurring from negative dielectric permittivity (thereby imaginary refractive index) of these small particles, giant electromagnetic energy fields are locally accumulated; making local discharge thus giving illuminated plasmoid ball. This paper explains the formation of giant electric field at electrostatic resonance, which is primary cause of localized discharge thus plasmoid illumination, is observed in microwave drilling experiments.

Ultracapacitors: Why, How, and Where is the Technology

Abstract: The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

Multi-index Mittag-Leffler Functions

Abstract: Consider the function defined for \(\alpha _{1},\ \alpha _{2} \in \mathbb{R}\) (α 1 2 +α 2 2 ≠ 0) and \(\beta _{1},\beta _{2} \in \mathbb{C}\) by the series $$\displaystyle{ E_{\alpha _{1},\beta _{1};\alpha _{2},\beta _{2}}(z) \equiv \sum _{k=0}^{\infty } \frac{z^{k}} {\varGamma (\alpha _{1}k +\beta _{1})\varGamma (\alpha _{2}k +\beta _{2})}\ \ (z \in \mathbb{C}). }$$ (6.1.1) Such a function with positive α 1 > 0, α 2 > 0 and real \(\beta _{1},\beta _{2} \in \mathbb{R}\) was introduced by Dzherbashian [Dzh60].