Faculty Publications
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Publications by NITK Faculty
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Item Recovery of Cu and Zn from complex sulphide ore(Institute of Physics Publishing custserv@iop.org, 2015) Talapaneni, T.; Sarkar, S.; Yedla, N.; Reddy, D.P.L.N.Complex Sulphide Ores are often found to be a close mutual association with each other and with the nonmetallic gangue. The beneficiation experiments showed that it would be very difficult to recover Cu and Zn from the lean complex Sulphide ores using traditional ore beneficiation methods. In the present work, leaching of complex sulfide ores in sulfuric acid was investigated by the Electro hydrometallurgy process. The lab-scale experiments were conducted to investigate the influences of pulp-density, electrolyte concentration, particle size, current density and time on recovery of Cu and Zn. The leach liquor obtained after electrolysis was subjected to Atomic Absorption Spectroscopy analysis for the recovery of minerals.Item Quantum Machine Learning: A Review and Current Status(Springer Science and Business Media Deutschland GmbH, 2021) Mishra, N.; Kapil, M.; Rakesh, H.; Anand, A.; Mishra, N.; Warke, A.; Sarkar, S.; Dutta, S.; Gupta, S.; Prasad Dash, A.; Gharat, R.; Chatterjee, Y.; Roy, S.; Raj, S.; Kumar Jain, V.; Bagaria, S.; Chaudhary, S.; Singh, V.; Maji, R.; Dalei, P.; Behera, B.K.; Mukhopadhyay, S.; Panigrahi, P.K.Quantum machine learning is at the intersection of two of the most sought after research areas—quantum computing and classical machine learning. Quantum machine learning investigates how results from the quantum world can be used to solve problems from machine learning. The amount of data needed to reliably train a classical computation model is evergrowing and reaching the limits which normal computing devices can handle. In such a scenario, quantum computation can aid in continuing training with huge data. Quantum machine learning looks to devise learning algorithms faster than their classical counterparts. Classical machine learning is about trying to find patterns in data and using those patterns to predict further events. Quantum systems, on the other hand, produce atypical patterns which are not producible by classical systems, thereby postulating that quantum computers may overtake classical computers on machine learning tasks. Here, we review the previous literature on quantum machine learning and provide the current status of it. © 2021, Springer Nature Singapore Pte Ltd.Item Rhodamine-based Cu2+-selective fluorosensor: Synthesis, mechanism, and application in living cells(2013) Sikdar, A.; Roy, S.; Haldar, K.; Sarkar, S.; Panja, S.S.A rhodamine B-based fluorescence probe (1) for the sensitive and selective detection of Cu2+ ion has been designed and synthesized using pyridine moiety. The optical properties of this compound have been investigated in acetonitrile-water binary solution (7:3 v/v). Compound 1 is found to be an excellent sensor for a biologically/physiologically very important transition metal ion (Cu2+) using only the two very different modes of measurements (absorption and emission); one case displayed intensity enhancement whereas in other case showed intensity depletion (quenching). A mechanistic investigation has been performed to explore the static nature of quenching process. The sensor has been found to be very effective in sensing Cu 2+ ion inside living cells also. © 2013 Springer Science+Business Media New York.Item Chaotic Scenario in Three-Component Fermi Plasma(Abdus Salam International Centre for Theoretical Physics, 2020) Ghosh, T.; Pramanick, S.; Sarkar, S.; Dey, A.; Chandra, S.Electron Acoustic Solitary structures in Fermi Plasma with two temperature electrons have various applications in space and laboratory-made plasmas. Formulation of an adequate theory is important to understand various physical systems with various physical parameters. The motion of two temperature electrons in a quantum Fermi plasma system highly affects the solitary profile of the system. We study the quantum Fermi plasma system with two temperature electrons where the streaming velocities of two-electron population are opposite. We consider quantum hydrodynamic model (QHD) and derive a linear dispersion relation for the system. For non-linear study of the system, we use standard perturbative technique to derive Kortewegde Vries Burger's equation and show the evolution of solitary profile with different plasma parameters. We analyse the stable Rouge wave structure using NLSE and show simulation results. We study the dynamical properties and phase plot for two-stream quantum Fermi plasma system with two temperature electrons. © 2020. All Rights Reserved.Item Homotopy Study of Spherical Ion-Acoustic Waves in Relativistic Degenerate Galactic Plasma(Institute of Electrical and Electronics Engineers Inc., 2022) Sarkar, S.; Sett, A.; Pramanick, S.; Ghosh, T.; Das, C.; Chandra, S.In this work, we start with the ion-acoustic waves in galactic plasma with the degenerate matter. We use the reductive perturbation technique to derive the spherical Kadomtsev-Petviashvili (SKP) equation. We next employ homotopy-aided symbolic simulation (HASS) to study the evolution of the spherical solitary wavefront. We compare the results obtained by HPM and RPT. To understand how the system behaves, we transform the evolutionary equations into a dynamical system. The phase portraits and the superperiodic waves reflect on the intricate processes within the plasma and determine the stability criteria and possible situations of chaos. The work will find applications in many astrophysical observations, such as electrostatic wave modes, gamma-ray bursts, and double-layer solitons. PACS-95.30.Qd, 52.65.-y, 52.35.-g, 52.35.Tc. © 1973-2012 IEEE.Item Circuit Complexity in Z2 EEFT(MDPI, 2023) Adhikari, K.; Choudhury, S.; Kumar, S.; Mandal, S.; Pandey, N.; Roy, A.; Sarkar, S.; Sarker, P.; Shariff, S.S.Motivated by recent studies of circuit complexity in weakly interacting scalar field theory, we explore the computation of circuit complexity in (Formula presented.) Even Effective Field Theories ((Formula presented.) EEFTs). We consider a massive free field theory with higher-order Wilsonian operators such as (Formula presented.), (Formula presented.), and (Formula presented.) To facilitate our computation, we regularize the theory by putting it on a lattice. First, we consider a simple case of two oscillators and later generalize the results to N oscillators. This study was carried out for nearly Gaussian states. In our computation, the reference state is an approximately Gaussian unentangled state, and the corresponding target state, calculated from our theory, is an approximately Gaussian entangled state. We compute the complexity using the geometric approach developed by Nielsen, parameterizing the path-ordered unitary transformation and minimizing the geodesic in the space of unitaries. The contribution of higher-order operators to the circuit complexity in our theory is discussed. We also explore the dependency of complexity on other parameters in our theory for various cases. © 2022 by the authors.Item A Simplified Bubble Size Relation Compatible with the Energy Minimization Multiscale Drag Model for Studying Hydrodynamics in a 2D Gas–Solid Tapered Fluidized Bed(John Wiley and Sons Inc, 2025) Sahoo, L.K.; Sarkar, S.Gas–solid fluidized bed reactors are extensively utilized in direct reduced iron production. In practice, these reactors will have a wide particle size distribution, which is better handled by tapered fluidized beds due to their vertical velocity gradient. Herein, a simplified bubble size relation is proposed to remove implicit interdependency between the bubble size and its drag coefficient in the bubble-based energy minimization multiscale (EMMS) heterogeneous drag model. Further, the proposed drag model is coupled with the two-fluid kinetic theory of granular flow model to investigate hydrodynamics. The heterogeneous flow structure predicted by the model is similar to experiments. Further, the bulk parameters such as bed expansion ratio and bubble fraction obtained from the simulations using a simplified EMMS drag model are compared and are found to be in good agreement with the experimental findings, with mean relative deviations of 3.95% and 14.64%, respectively. The time-averaged bubble fraction and bed expansion ratio are found to increase with air velocity and decrease with taper angle, whereas a reverse trend is observed for the mean particulate fluidized area fraction. Based on the current study, the taper angle between 5° and 10° is found to be most suitable. © 2024 Wiley-VCH GmbH.Item An Experimental Investigation of Slugging Phenomenon in 2D Binary Gas–Solid Tapered Fluidized Beds(John Wiley and Sons Inc, 2025) Sahoo, L.K.; Sarkar, S.Gas–solid fluidized beds are widely employed in metallurgical industries to produce direct reduced iron. For such practical applications, tapered fluidized beds are most suitable for handling particles with wide size distribution due to the axial velocity gradient. Herein, the slug behavior in binary tapered fluidized beds has been studied using a high-speed camera and digital image analysis method. The influence of taper angle, air velocity, and fine fraction on local parameters such as slug size, rise velocity, and aspect ratio, and bulk parameters such as slug number and its area fraction, and bed expansion ratio has been investigated. The local parameters increase with taper angle, air velocity, and fine fraction. The slug area fraction and the bed expansion ratio increase with air velocity and fine fraction. The bed expansion ratio increases while the slug area fraction decreases with taper angle. The slug number fraction, slug area fraction, and bed expansion ratio range from 0.027–0.241, 0.20–0.63, and 1.11–1.42, as taper angle, air velocity, and binary composition vary from 0°–15°, 0.20–0.35 m s?1, and 0.25–0.75, respectively. An empirical correlation is proposed for bed expansion ratio prediction. Based on the present investigation, the optimum taper angle is 5°–10°. © 2024 Wiley-VCH GmbH.Item Controlling the Morphology and Orientation of the Helical Self-Assembly of Pyrazine Derivatives by Tuning Hydration Shells(John Wiley and Sons Inc, 2025) Sarkar, S.; Mathath, A.V.; Chakraborty, D.A combination of density functional theory (DFT) and classical molecular dynamics simulations is performed to unveil the guiding force in the self-assembly process of the pyrazine-based biopolymers to helical nanostructures. The highlight of the study shows the decisive role of the solvent-ligand H-bonding and the inter-molecular pi-pi stacking not only ensures the unidirectional packing of the helical structure but also the rotation of left-handed to the right-handed helical structure of the molecule. This transition is supported by the bulk release of the “ordered” water molecules. The extent of this bonding can be tuned by the temperature, concentration, and type of the metal ions. Smaller ions like Na+ and Al3+ destroy the structure, whereas bigger ions like Zn2+, Ni2+, and Au3+ preserve and rotate the structure according to their concentration. The interaction energy between the pyrazine derivatives is found to be high (?9000 kJ mol?1) for right-handed rotation of the helix, which increases further with the addition of D-histidine, forming a superhelical structure (?10300 kJ mol?1). The insights gained from this work can be used to generate nanostructures of desired morphology. © 2025 Wiley-VCH GmbH.Item Mathematical Modeling of Fluidized Bed Magnetizing Roasting of Iron Ore Fines(John Wiley and Sons Inc, 2025) Sahoo, L.K.; Mantripragada, V.T.; Sarkar, S.The fluidized bed magnetizing roasting of low-grade iron ore fines is employed as a beneficiation technique in iron-making and steel-making industries. In the present work, the unreacted shrinking core reaction kinetic model is coupled with the two-fluid and kinetic theory of granular flow gas–solid flow model to simulate magnetizing roasting of hematite to magnetite in iron ore fines using a fluidized bed reactor. The model is validated with published experimental findings. Thereafter, the influence of different process parameters such as gas temperature, composition, velocity, and particle size on the reduction fraction and rate along with (Formula presented.) mass fraction and emission is studied. The reduction rate increases with gas temperature and (Formula presented.) mass fraction while it decreases with particle size. The (Formula presented.) emission increases with gas temperature, particle size, and (Formula presented.) mass fraction. However, the influence of gas velocity on these parameters is not significant. The reduction rate and time vary from 0.0010 to 0.0067 s?1 and 65 to 553 s, respectively, at a reduction fraction of 0.5. The (Formula presented.) mass fraction and emission range from 0.80 to 0.92 and from 0.63 to 4.14 g kg?1 ore, respectively. © 2024 Wiley-VCH GmbH.