arXiv subjects

Prakash Kumar

Publications and source records attributed to Prakash Kumar.

5 recordsLinked to original sources

arXiv2026

An Approach to Simultaneous Acquisition of Real-Time MRI Video, EEG, and Surface EMG for Articulatory, Brain, and Muscle Activity During Speech Production

Speech production is a complex process spanning neural planning, motor control, muscle activation, and articulatory kinematics. While the acoustic speech signal is the most accessible product of the speech production act, it does not directly reveal its causal neurophysiological substrates. We present the first simultaneous acquisition of real-time (dynamic) MRI, EEG, and surface EMG, capturing several key aspects of the speech production chain: brain signals, muscle activations, and articulatory movements. This multimodal acquisition paradigm presents substantial technical challenges, including MRI-induced electromagnetic interference and myogenic artifacts. To mitigate these, we introduce an artifact suppression pipeline tailored to this tri-modal setting. Once fully developed, this framework is poised to offer an unprecedented window into speech neuroscience and insights leading to brain-computer interface advances. The source code and data are available.

eess.AS↗

arXiv2026

Analytical characterization of self sustained nonlinear oscillators modelling human walking and bouncing

Researchers have developed hybrid Van der Pol Rayleigh Duffing type oscillators to model human induced forces; however, their analytical framework has largely relied on the Lindstedt Poincare perturbation method, energy balance approaches, and harmonic balance techniques. This paper aims to apply new mathematical tools to these existing models and address potential research gaps. An analytical proof for the stability of the limit cycle has been formulated by using the Krylov Bogolyubov perturbation method. The multiple scales method has been modified to highlight an iterative algorithm for determining the order of approximation required to capture nonlinear effects. The describing function method is utilised to formulate an alternate amplitude. Comparisons between first order amplitudes obtained from perturbation analysis and the describing function formulations reveal conditions under which the two approaches converge. These conditions are exploited to formulate additional constraints for the estimation of model parameters, offering a systematic alternative to purely optimisation based approaches.

nlin.AO↗

arXiv2024

Analysis of a Hydrodynamic Thermoelastic Mixture Model

This study proposes and explores a hydrodynamic thermo-elasticity system within the context of mixture models, encompassing fluid and solid phases, with particular emphasis on biological tissues and tumor-related phenomena. While tumor growth dynamics are not explicitly modeled yet, this work examines the interaction between thermal effects and hydrodynamics on short-time scales where the tumor size typically remains stable. We establish the existence of a unique weak solution within the framework of implicit evolution equations where we exploit the intricate coupling mechanisms inherent to the PDE system. To further investigate the model, we then study the one-dimensional model and explore in detail the complex interplay between fluid flow, solid deformation, and heat transfer. This complex coupled system of equations is then reduced over a short time scale to obtain semi-analytical solutions.

math.AP↗

arXiv2022

High pressure structural and magneto-transport studies on type-II Dirac semimetal candidate Ir2In8S: Emergence of superconductivity upon decompression

The structural and magneto-transport properties of type-II Dirac semimetal candidate Ir2In8S have been investigated under high pressure. The ambient tetragonal structure (P4_2/mnm) is found to be stable up to 7 GPa, above which the system takes an orthorhombic Pnnm structure, possibly destroying the Dirac cones due to the loss of the four-fold screw symmetry. In the tetragonal structure, a gradual suppression of the transverse magneto-resistance and a rapid change in the magnetic field dependence above 50K suggest possible T-dependent Fermi surface modification. In the high pressure phase, the metallic character increases marginally (as evident from the increased RRR value) accompanied with suppressed magneto-resistance, without emergence of superconductivity up to 20 GPa and down to 1.4K. Most surprisingly, upon release of pressure to 0.2 GPa, a sharp resistance drop below 4K is observed, field varying measurements confirm this as the onset of superconductivity. The observed changes of the carrier density and mobility in the pressure-released tetragonal phase indicate electronic structural modification resulting from the irreversible polyhedral distortion. A simultaneous increase in the residual resistivity and carrier density upon decompression indicates that an enhanced impurity scattering play a key role in the emergence of superconductivity in the tetragonal Ir2In8S, making it an ideal platform to study topological superconductivity.

cond-mat.supr-con↗

arXiv2019

Developing ZnO Nanoparticle embedded Antimicrobial Starch Biofilm for Food Packaging

Starch based bio-films act as biodegradable packaging material for coating and wrapping food products, which is alternate to the synthetic polymer. Nanoparticles (NPs) are also alternative to antibiotics to target pathogens. Through interaction of nanoparticles with food packaging material the overall quality of the packaged food also get enhanced. In this research work, ZnO NP embedded corn starch films were developed. First, ZnO NP were synthesized by two approaches (a) Sol-gel approach and (b) Green synthesis approach; and then ZnO NP embedded corn-starch bio-films were developed. In sol-gel technique ZnO NP were synthesized at different pH ranging from 8 to 11, with an average crystallite size of 28 to 53 nm. In green synthesis technique ZnO NP were synthesized by using Azadirachta indica (Neem) at different concentration of 2\% and 3\% with an average crystallite size of 36 nm and 32 nm, respectively. Characterization of synthesized ZnO NPs were done with XRD, UV-DRS, UV-VIS, FTIR and FE-SEM. The functional properties of the ZnO embedded starch film were enhanced with addition of 5\% citric acid solution(w/w) as cross-linker and 0.90 g glycerol(w/w) as plasticizer. Film-F1 embedded with chemically synthesized ZnO NP, Film-F2 embedded with biochemcially synthesized ZnO NP and Film-F3 without being embedded by any NPs. Characterization of synthesized films were done with SEM and XRD. Film solution of F2 showed higher antimicrobial effectiveness than F1; against E.coli and S.aureus bacterial strains with an inhibition zone of 14 mm and 6 mm. 7days biodegradability analysis of the films were also done. Along with this, their current application and future perspectives in the food sector are also explored

physics.app-ph↗