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.

An insight into Newton's cooling law using fractional calculus

Abstract: For small temperature differences between a heated body and its environment, Newton's law of cooling predicts that the instantaneous rate of change of temperature of any heated body with respect to time is proportional to the difference in temperature of the body with the ambient, time being measured in integer units Our experiments on the cooling of different liquids (water, mustard oil, and mercury) did not fit the theoretical predictions of Newton's law of cooling in this form The solution was done using both Caputo and Riemann-Liouville type fractional derivatives to check if natural phenomena showed any preference in mathematics In both cases, we find that cooling of liquids has an identical value of the fractional derivative of time that increases with the viscosity of the liquid On the other hand, the cooling studies on metal alloys could be fitted exactly by integer order time derivative equations The proportionality constant between heat flux and temperature difference was examined with resp

Joining of Mild Steel Plates Using Microwave Energy

Abstract: This paper describes joining of bulk MS (mild steel) plates using a domestic microwave oven at a frequency of 2.45 GHz and a power of 900 W. Microwave Hybrid Heating (MHH) is used for joining of MS plate by placing an interlayer of Ni powder of average thickness of about 0.3 mm between two interfacing surfaces. Characterization of the joints has been carried out using X ray diffraction (XRD), SEM (Scanning Electron Microscope), and Vickers micro indentation. The back scattered electron (BSE) image shows complete melting of powder particle yielding diffusion bonding between interfacing powder particles and MS plates The average micro hardness of the joints observed to be 420 ± 30 Hv which is significantly higher than the substrate hardness of 230 ± 10 Hv. The results obtained after performing tensile test show that the joints have an average strength of 250 MPa with a percentage elongation of 6 percent

Investigation on microstructure and mechanical properties of the dissimilar weld between mild steel and stainless steel-316 formed using microwave energy

Abstract: Dissimilar weld between a mild steel and a stainless steel-316 was formed by exposing the candidate materials to electromagnetic radiation in the microwave band. Characterisations of the joints wer...

Fractional Order PID controller design for speed control of chopper fed DC Motor Drive using Artificial Bee Colony algorithm

Abstract: This article deals with an interesting application of Fractional Order (FO) Proportional Integral Derivative (PID) Controller for speed regulation in a DC Motor Drive. The design of five interdependent Fractional Order controller parameters has been formulated as an optimization problem based on minimization of set point error and controller output. The task of optimization was carried out using Artificial Bee Colony (ABC) algorithm. A comparative study has also been made to highlight the advantage of using a Fractional order PID controller over conventional PID control scheme for speed regulation of application considered. Extensive simulation results are provided to validate the effectiveness of the proposed approach.

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].