The nature of interactions between heme protein human hemoglobin (HHb) and gold nanoparticles of two different morphologies that is GNP (spherical) and GNS (star-shaped) have been investigated by using UV-vis absorption, steady state fluorescence, synchronous fluorescence, resonance light scattering (RLS), time resolved fluorescence, FT-IR, and circular dichroism (CD) techniques under physiological condition of pH ~7 at ambient and different temperatures. Analysis of the steady state fluorescence quenching of HHb in aqueous solution in the presence of GNP and GNS suggests that the nature of the quenching is of static type. The static nature of the quenching is also confirmed from time resolved data.
View Article and Find Full Text PDFAn array of excitable Josephson junctions under a global mean-field interaction and a common periodic forcing shows the emergence of two important classes of coherent dynamics, librational and rotational motion, in the weaker and stronger coupling limits, respectively, with transitions to chimeralike states and clustered states in the intermediate coupling range. In this numerical study, we use the Kuramoto complex order parameter and introduce two measures, a libration index and a clustering index, to characterize the dynamical regimes and their transitions and locate them in a parameter plane.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
December 2015
We report chimeralike states in an ensemble of oscillators using a type of global coupling consisting of two components: attractive and repulsive mean-field feedback. We identify the existence of two types of chimeralike states in a bistable Liénard system; in one type, both the coherent and the incoherent populations are in chaotic states (which we refer to as chaos-chaos chimeralike states) and, in another type, the incoherent population is in periodic state while the coherent population has irregular small oscillation. We find a metastable state in a parameter regime of the Liénard system where the coherent and noncoherent states migrate in time from one to another subpopulation.
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