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

In this paper, the dynamical behaviors of a delayed predator-prey model (PPM) with nonlinear harvesting effortsby using imprecise biological parameters are studied. A method is proposed to handle these imprecise parameters by using a parametric form of interval numbers. The proposed PP M is presented with Crowley-Martin type of predation and Michaelis-Menten type prey harvesting. The existence of various equilibrium points and the stability of the system at these equilibrium points are investigated. Analytical study reveals that the delaymodel exhibits a stable limit cycle oscillation. Computer simulations are carried out to illustrate the main analytical findings.

ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES

Stability analysis of a delayed predator-prey model with nonlinear harvesting efforts using imprecise biological parameters

World University root node

Bulletin of the American Physical Society

Astromers: Astrophysical Isomers

The cosmic evolution of the chemical elements from the Big Bang to the present time is driven by nuclear fusion reactions inside stars and stellar explosions. A cycle of matter recurrently re-processes metal-enriched stellar ejecta into the next generation of stars. The study of cosmic nucleosynthesis and this matter cycle requires the understanding of the physics of nuclear reactions, of the conditions at which the nuclear reactions are activated inside the stars and stellar explosions, of the stellar ejection mechanisms through winds and explosions, and of the transport of the ejecta towards the next cycle, from hot plasma to cold, star-forming gas. Due to the long timescales of stellar evolution, and because of the infrequent occurrence of stellar explosions, observational studies are challenging, as they have biases in time and space as well as different sensitivities related to the various astronomical methods. Here, we describe in detail the astrophysical and nuclear-physical processes involved in creating two radioactive isotopes useful in such studies, and. Due to their radioactive lifetime of the order of a million years, these isotopes are suitable to characterise simultaneously the processes of nuclear fusion reactions and of interstellar transport. We describe and discuss the nuclear reactions involved in the production and destruction of and, the key characteristics of the stellar sites of their nucleosynthesis and their interstellar journey after ejection from the nucleosynthesis sites. This allows us to connect the theoretical astrophysical aspects to the variety of astronomical messengers presented here, from stardust and cosmic-ray composition measurements, through observation of rays produced by radioactivity, to material deposited in deep-sea ocean crusts and to the inferred composition of the first solids that have formed in the Solar System. We show that considering measurements of the isotopic ratio of to eliminate some of the unknowns when interpreting astronomical results, and discuss the lessons learned from these two isotopes on cosmic chemical evolution. This review paper has emerged from an ISSI-BJ Team project in 2017-2019, bringing together nuclear physicists, astronomers, and astrophysicists in this inter-disciplinary discussion. ©

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Publications of the Astronomical Society of Australia

The radioactive nuclei and in the Cosmos and in the solar system

The dynamics of small, yet heavy, identical particles in turbulence exhibits singularities, called caustics, that lead to large fluctuations in the spatial particle-number density, and in collision velocities. For large particle inertia, the fluid velocity at the particle position is essentially a white-noise signal and caustic formation is analogous to Kramers escape. Here we show that caustic formation at small particle inertia is different. Caustics tend to form in the vicinity of particle trajectories that experience a specific history of fluid-velocity gradients, characterized by low vorticity and a violent strain exceeding a large threshold. We develop a theory that explains our findings in terms of an optimal path to caustic formation that is approached in the small inertia limit. © 2021 authors.

Physical Review Fluids

Paths to caustic formation in turbulent aerosols

The dynamics and deformation of red blood cells (RBCs) in microcirculation affect the flow resistance and transport properties of whole blood. One of the key properties that can alter RBC dynamics in flow is the contrast λ (or ratio) of viscosities between RBC cytosol and blood plasma. Here, we study the dependence of RBC shape and dynamics on the viscosity contrast in tube flow, using mesoscopic hydrodynamics simulations. State diagrams of different RBC dynamical states, including tumbling cells, parachutes, and tank-treading slippers, are constructed for various viscosity contrasts and wide ranges of flow rates and tube diameters (or RBC confinements). Despite similarities in the classification of RBC behavior for different viscosity contrasts, there are notable differences in the corresponding state diagrams. In particular, the region of parachutes is significantly larger for λ = 1 in comparison to λ = 5. Furthermore, the viscosity contrast strongly affects the tumbling-to-slipper transition, thus modifying the regions of occurrence of these states as a function of flow rate and RBC confinement. Also, an increase in cytosol viscosity leads to a reduction in membrane tension induced by flow stresses. Physical mechanisms that determine these differences in RBC dynamical states as a function of λ are discussed. © Copyright © 2021 Dasanna, Mauer, Gompper and Fedosov.

Frontiers in Physics

Importance of Viscosity Contrast for the Motion of Erythrocytes in Microcapillaries

Background: Chorea-acanthocytosis (ChAc) is a rare hereditary neurodegenerative disease with deformed red blood cells (RBCs), so-called acanthocytes, as a typical marker of the disease. Erythrocyte sedimentation rate (ESR) was recently proposed as a diagnostic biomarker. To date, there is no treatment option for affected patients, but promising therapy candidates, such as dasatinib, a Lyn-kinase inhibitor, have been identified. Methods: RBCs of two ChAc patients during and after dasatinib treatment were characterized by the ESR, clinical hematology parameters and the 3D shape classification in stasis based on an artificial neural network. Furthermore, mathematical modeling was performed to understand the contribution of cell morphology and cell rigidity to the ESR. Microfluidic measurements were used to compare the RBC rigidity between ChAc patients and healthy controls. Results: The mechano-morphological characterization of RBCs from two ChAc patients in an off-label treatment with dasatinib revealed differences in the ESR and the acanthocyte count during and after the treatment period, which could not directly be related to each other. Clinical hematology parameters were in the normal range. Mathematical modeling indicated that RBC rigidity is more important for delayed ESR than cell shape. Microfluidic experiments confirmed a higher rigidity in the normocytes of ChAc patients compared to healthy controls. Conclusions: The results increase our understanding of the role of acanthocytes and their associated properties in the ESR, but the data are too sparse to answer the question of whether the ESR is a suitable biomarker for treatment success, whereas a correlation between hematological and neuronal phenotype is still subject to verification. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Biomolecules

The erythrocyte sedimentation rate and its relation to cell shape and rigidity of red blood cells from chorea-acanthocytosis patients in an off-label treatment with dasatinib

arXiv preprint arXiv:2108.

Distinguishing Phases via Non-Markovian Dynamics of Entanglement in Topological Quantum Codes under Parallel Magnetic Field

Ovchinnikov postulated the possibility of ferromagnetism in organic compounds having a mixed density of sp 3 and sp 2 carbon atoms. Such systems provide an interesting avenue for exploring magnetism in the absence of the quintessential d- and f-block elements as ingredients. As graphene oxide (GO) and its derivatives naturally possess a mixture of sp 3 and sp 2 carbon atoms, it is pertinent to look at them as potential candidates for Ovchinnikov ferromagnetism. We have looked at the evolution of magnetic property in a series of GO samples with a gradual increase in the degree of oxidation and hence the sp 3/sp 2 fraction. Starting with a GO sample with a high sp 3/sp 2 ratio, we utilize chemical reduction technique to prepare another set of reduced graphene oxide (rGO) samples. Magnetization measurements on these samples further illustrate the importance of sp 3/sp 2 fraction on magnetic behavior suggesting GO and its derivatives as a potential Ovchinnikov ferromagnet candidate. The evolution of magnetic moment with sp 3/sp 2 carbons can be utilized in carbon based spintronic applications. © 2021 IOP Publishing Ltd.

Journal of Physics Condensed Matter

Graphene oxide and its derivatives as potential Ovchinnikov ferromagnets

Application of probiotics in aquaculture helps to improve the survivability, growth and immunity of aquatic organism in sustainable aquaculture practices. This study was conducted to evaluate the probiotic potentiality of Streptomyces antibioticus EW1 and Bacillus cereus EW5 isolated from the digestive tract of earthworm (Eisenia fetida) and also determine their effects as probiotic in juvenile catfish (Heteropneustes fossilis). The bio safety assay confirmed that the isolates were not pathogenic to the host fish. These strains were able to survive in acidic as well as alkaline conditions, higher tolerance to bile salt as well as gastric juice and high surface hydrophobicity to solvents and displayed extracellular enzyme activity and moreover susceptibility to various antibiotics. Their antimicrobial activity was assessed against two fish pathogens: Aeromonas veronii (MN602971) and Steno-trophomonas maltophilia (MN602972). Among two isolates, the EW1 confirmed good antimicrobial activity against fish pathogens. The isolated bacterial strains were identified and established on the basis of their colony morphology, biochemical characteristics and 16S rRNA sequencing which revealed that the isolates exhibited 99 \% sequence homology with Streptomyces antibioticus EW1 (MH301104) and Bacillus cereus EW5 (MH301102). A 45-day feeding trial was conducted to examine the effect of probiotic inoculated fish diet for the freshwater catfish Heteropneustes fossilis. Among three isonitrogenous (30 \% CP) diets: RD (reference diet), T1 (diet with Streptomyces antibioticus) and T2 (diet with Bacillus cereus), fish fed T1 diet showed significantly higher growth, digestibility and higher values of crude protein and lipid than fishes reared with T2 and RD. The result of present study suggest that diet supplemented with Streptomyces antibioticus (T1) can be perform as safe probiotic and alternative protein source in the formulation of diet for H. fossilis.

AQUACULTURE REPORTS

Evaluation of the probiotic potential of Streptomyces antibioticus and Bacillus cereus on growth performance of freshwater catfish Heteropneustes fossilis

We study the spin-1/2 ferromagnetic Heisenberg-Kitaev-Γ model in the anisotropic (Toric code) limit to reveal the nature of the quantum phase transition between the gapped Z2 quantum spin liquid and a spin-ordered phase (driven by Heisenberg interactions) as well as a trivial paramagnet (driven by pseudodipolar interactions Γ). The transitions are obtained by a simultaneous condensation of the Ising electric and magnetic charges - the fractionalized excitations of the Z2 quantum spin liquid. Both these transitions can be continuous and are examples of deconfined quantum critical points. Crucial to our calculations are the symmetry implementations on the soft electric and magnetic modes that become critical. In particular, we find strong constraints on the structure of the critical theory arising from time reversal and lattice translation symmetries with the latter acting as an anyon permutation symmetry that endows the critical theory with a manifestly self-dual structure. We find that the transition between the quantum spin liquid and the spin-ordered phase belongs to a self-dual modified Abelian Higgs field theory while that between the spin liquid and the trivial paramagnet belongs to a self-dual Z2 gauge theory. We also study the effect of an external Zeeman field to show an interesting similarity between the polarized paramagnet obtained due to the Zeeman field and the trivial paramagnet driven pseudodipolar interactions. Interestingly, both the spin liquid and the spin-ordered phases have easily identifiable counterparts in the isotropic limit and the present calculations may shed insights into the corresponding transitions in the material relevant isotropic limit. © 2020 American Physical Society.