Department of Physics

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

We investigate temporal cooperative behaviour in a realistic model of a molecular motor-cargo assembly by simulating a one-dimensional stochastic model of a motor-bound bead in an optical trap. Here, each motor is linked to a bead through an elastic spring, and performs forward and backward hopping motions on the filament. The rates characterising the forward and backward steps are different because of the free energy change associated with ATP hydrolysis. Apart from forward and backward hopping, motor bind to, and unbind from the filament with specific rates, while remaining attached to the bead. The bead is subjected to elastic force originating from the stretched motor-springs, thermal noise as well as an external force from an optical trap. We constructed a Gillespie code which can simulate the dynamics of up to six motors. Our results indicate that the emergence of cooperative behaviour, as observed in experiments, is closely connected with the load-sharing properties of the team. Simulation results of the mean first passage time show excellent agreement with experimental data of the same in the literature. © 2022, Indian Association for the Cultivation of Science.

World University root node

Indian Journal of Physics

Temporal cooperativity of a group of elastically coupled motor proteins stalled in an optical trap

The present study deals with the dynamical response of an eco-epidemiological model consisting of prey and predator species having infection in prey population. The inclusion of prey refugia is taken into account to avoid predator attack. The entire prey population is divided into two parts: healthy prey which are capable of reproducing following the logistic law and infected prey which is removed by predation or death before having the possibility of reproducing. Also we have considered the role of harvesting of the susceptible prey and the predator. For biological validity of the model, positivity and boundedness of the system are studied. The dynamical behaviour of the model has been analyzed elaborately. The stability aspects of the basic model around the infection free state, predator free state and the infected steady state from a local as well as a global perspective are studied. The main aim is to study the role of harvesting on the dynamics of disease propagation and/or eradication. By considering harvesting in susceptible prey and predator population, our study gives a new direction to eco-epidemiological model. Changes in local and global dynamical behaviour in terms of important system parameters are obtained. By the numerical simulation Hopf-bifurcation and the stable and unstable behaviour of the system due to harvesting and rate of infection have been observed.

ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES

Qualitative analysis of an eco-epidemiological model with a role of prey and predator harvesting

Bulletin of the American Physical Society

Cavity magnonics with van der Waals antiferromagnet

We report a systematic study on the thermal transport properties of gold nanoparticles (Au NPs) decorated single-layer graphene on a SiO2/Si substrate by the opto-thermal Raman technique. Our results, with moderate Au NPs coverage (<10%), demonstrate an enhancement in the thermal conductivity of graphene by ∼55% from its pristine value and a decrement in the interface conductance by a factor of 1.5. A detailed analysis of our results shows the importance of the photo-thermal conversion efficiency of Au NPs, plasmon-phonon coupling and lattice modifications in the graphene developed after gold nanoparticles deposition in enhancing the thermal conductivity and reducing the interface thermal conductance of the system. Our study paves way for a better understanding of the thermal management in such hybrid systems, which are envisioned as excellent candidates for optoelectronics and photonics applications. © 2022 IOP Publishing Ltd.

Nanotechnology

Investigating the thermal transport in gold decorated graphene by opto-thermal Raman technique

In plant breeding research, naturally existing genetic variability has been successfully utilized to some extent for sustainable production of desirable crops and the diversity in plant genetic resources is most useful part to the breeders. The present experiment was conducted to estimate the genetic variation as well as divergence also of 29 sesame genotypes based on morphological traits. The high genotypic co-efficient of variation (GCV) and phenotypic co-efficient variation (PCV) observed for number of branches / plant and also for no. of capsules / plant. High heritability coupled with high genetic advance was estimated against seed yield / plant, number of branches / plant and capsules/ plant and HI indicating predominant role of additive genetic components for their expression and also indicating better scope for utilization of direct selection for those traits. The genotypes are grouped into 5 clusters based on 16 morphological traits i.e. Plant height, root length, vegetative dry weight, leaf-area index, days to 50\% flowering, no. of branches per plant, number of capsules per plant, capsule length, number seeds per capsule, 100 seed weight, seed yield per plant. The maximum inter-cluster distance noticed between cluster II and IV indicating their most diverse relationship. Genotypes of two clusters with wider genetic diversity and with desirable agronomic traits were selected as promising genotypes for hybridization programmes. Crosses can be made between genotypes of cluster II with genotypes of cluster IV to achieve promising recombinants.

PLANT SCIENCE TODAY

The estimation of genetic variability and genetic divergence of some advance lines of sesame based on morphological traits

We study interacting active Brownian particles (ABPs) with a space-dependent swim velocity via simulation and theory. We find that, although an equation of state exists, a mechanical equilibrium does not apply to ABPs in activity landscapes. The pressure imbalance originates in the flux of polar order and the gradient of swim velocity across the interface between regions of different activity. An active-passive patch system is mainly controlled by the smallest global density for which the passive patch can be close packed. Below this density a critical point does not exist and the system splits continuously into a dense passive and a dilute active phase with increasing activity. Above this density and for sufficiently high activity the active phase may start to phase separate into a gas and a liquid phase caused by the same mechanism as motility-induced phase separation of ABPs with a homogeneous swim velocity. © 2022 The Author(s). Published by IOP Publishing Ltd on behalf of the Institute of Physics and Deutsche Physikalische Gesellschaft.

New Journal of Physics

Interacting particles in an activity landscape

The erythrocyte (or red blood cell) sedimentation rate (ESR) is commonly interpreted as a measure of cell aggregation and as a biomarker of inflammation. It is well known that an increase of fibrinogen concentration, an aggregation-inducing protein for erythrocytes, leads to an increase of the sedimentation rate of erythrocytes, which is generally explained through the formation and faster settling of large disjoint aggregates. However, many aspects of erythrocyte sedimentation conform well with the collapse of a particle gel rather than with the sedimentation of disjoint aggregates. Using experiments and cell-level numerical simulations, we systematically investigate the dependence of ESR on fibrinogen concentration and its relation to the microstructure of the gel-like erythrocyte suspension. We show that for physiological aggregation interactions, an increase in the attraction strength between cells results in a cell network with larger void spaces. This geometrical change in the network structure occurs due to anisotropic shape and deformability of erythrocytes and leads to an increased gel permeability and faster sedimentation. Our results provide a comprehensive relation between the ESR and the cell-level structure of erythrocyte suspensions and support the gel hypothesis in the interpretation of blood sedimentation. © 2022 American Physical Society.

Fulltext

Physical Review E

Erythrocyte sedimentation: Effect of aggregation energy on gel structure during collapse

arXiv preprint arXiv:2202.

Effects of magnetic and non-magnetic doping on the vortex lattice in MgB

Abstract: We study the velocity-force (V-F) relation for a Brownian ratchet consisting of a linear rigid polymer growing against a diffusing barrier, acted upon by a opposing constant force (F). Using a careful mathematical analysis, we derive the V-F relations in the extreme limits of fast and slow barrier diffusion. In the first case, V depends exponentially on the load F, in agreement with the well-known formula proposed by Peskin, Odell and Oster (1993), while the relationship becomes linear in the second case. For a bundle of two filaments growing against a common barrier, equal sharing of load in the corresponding V-F relation is predicted by a mean-field argument in both limits. However, the scaling behaviour of velocity with the number of filaments is different for the two cases. In the limit of large D, the validity of the mean-field approach is tested, and partially supported by a detailed and rigorous analysis. Our principal predictions are also verified in numerical simulations. Graphic abstract: [Figure not available: see fulltext.]. © 2022, The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature.

European Physical Journal E

Force-velocity relation and load-sharing in the linear polymerization ratchet revisited: the effects of barrier diffusion

This paper studies the uniqueness of two non-integral finite ordered meromorphic functions with finitely many poles when they share two finite sets. Also, it provides an answer to a question posed by Gross for a particular class of meromorphic functions. Moreover, some observations are made on some results due to Sahoo and Karmakar, Acta Univ. Sapient. Math., doi:10.2478/ausm-2018-0025; Sahoo and Sarkar, Bol. Soc. Mat. Mex., doi:10.1007/s40590-019-00260-4.