383 research outputs found

    Investigation of the dynamical slowing down process in soft glassy colloidal suspensions: comparisons with supercooled liquids

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    The primary and secondary relaxation timescales of aging colloidal suspensions of Laponite are estimated from intensity autocorrelation functions obtained in dynamic light scattering (DLS) experiments. The dynamical slowing down of these relaxation processes are compared with observations in fragile supercooled liquids by establishing a one-to-one mapping between the waiting time since filtration of a Laponite suspension and the inverse of the temperature of a supercooled liquid that is rapidly quenched towards its glass transition temperature. New timescales, such as the Vogel time and the Kauzmann time, are extracted to describe the phenomenon of dynamical arrest in Laponite suspensions. In results that are strongly reminiscent of those extracted from supercooled liquids approaching their glass transitions, it is demonstrated that the Vogel time calculated for each Laponite concentration is approximately equal to the Kauzmann time, and that a strong coupling exists between the primary and secondary relaxation processes of aging Laponite suspensions. Furthermore, the experimental data presented here clearly demonstrates the self-similar nature of the aging dynamics of Laponite suspensions within a range of sample concentrations.Comment: 30 pages, includes supporting informatio

    Countable Fuzzy Topological Space and Countable Fuzzy Topological Vector Space

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    This paper deals with countable fuzzy topological spaces, a generalization of the notion of fuzzy topological spaces. A collection of fuzzy sets F on a universe X forms a countable fuzzy topology if in the definition of a fuzzy topology, the condition of arbitrary supremum is relaxed to countable supremum. In this generalized fuzzy structure, the continuity of fuzzy functions and some other related properties are studied. Also the class of countable fuzzy topological vector spaces as a generalization of the class of fuzzy topological vector spaces has been introduced and investigated

    A Note on Strongly Lower Semi-Continuous Functions and the Induced Fuzzy Topological Space Generated by Them

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    A new class of functions called strongly lower semi-continuous (SLSC) functions is defined and its properties are studied. It is shown that the arbitrary supremum and finite infimum of SLSC functions are again SLSC. Using these functions, an induced fuzzy topological space, called s-induced fuzzy topological space on a topological space (X, T), is introduced. Moreover, some incorrect results on fuzzy topological spaces obtained previously by some authors are identified and modified accordingly. Examples of the newly defined induced space are given and their various properties are investigated. Interrelationships between a fuzzy topological space (X, F) and the s-induced fuzzy topological space generated by the crisp members of F are examined. In this process, different lower semi-continuities and induced fuzzy spaces generated by them have been defined in a general set up and their few properties have been studied

    LIGO-VIRGO constraints on dark matter and leptogenesis triggered by a first order phase transition at high scale

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    We study the possibility of constraining a scenario with high scale first order phase transition (FOPT) responsible for the cogenesis of baryon and dark matter using gravitational wave (GW) (non)-observations. While the FOPT at high scale is responsible for generating baryon asymmetry through leptogenesis and dark matter via the \textit{mass-gain} mechanism, the resulting GW spectrum falls within the ongoing LIGO-VIRGO experimental sensitivity. The dark matter is preferred to be in the non-thermal ballpark with sub-GeV masses and the criteria of successful dark matter relic rules out a large portion of the parameter space consistent with high scale FOPT and successful leptogenesis. Some part of the parameter space allowed from dark matter and leptogenesis criteria also gives rise to a large signal-to-noise ratio at ongoing experiments and hence can be disfavoured in a conservative way from the non-observation of such stochastic GW background. Future data from ongoing and planned experiments will offer a complementary and indirect probe of the remaining parameter space which is typically outside the reach of any direct experimental probe.Comment: 15 pages, 5 captioned figure

    Swift J1728.9-3613 is a black hole X-ray binary: spectral and timing study using NICER

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    We study different timing and spectral properties of the new Galactic X-ray transient Swift J1728.9-3613 using NICER and Swift, discovered by the Burst Alert Telescope (BAT) on the Neil Gehrels Swift Observatory. The source went through multiple transitions to different spectral states during the outburst, and the complete evolution created a q-shaped track in the hardness intensity diagram. A partial hysteresis is also observed in the RMS-intensity diagram, which is another well-defined phenomenon of black hole transients. In SIMS, power density spectra were dominated by broadband noise components, and two type B QPOs were detected. We have fitted 1-10 keV energy spectra obtained from NICER observations that were performed during the outburst, and the temporal evolution of spectral parameters were studied. On MJD 58584.69, a small-scale reflare happened, and we observed that the spectral index decreased to a much lower value associated with finite changes in other spectral parameters also, and the 1-10 keV averaged flux also increased. We observed that the innermost radius of the accretion disc was almost constant during the soft state, which corresponds to the Innermost Stable Circular Orbit (ISCO). We have measured the lower limit of mass of the compact object to be approximately 4.6 M, considering a non-spinning black hole binary system, by fitting 1-10 keV NICER spectra with the diskbb component. The soft-to-hard transition occurred when the bolometric luminosity was 0.01 times the Eddington luminosity. Based on our combined study of the evolution of the timing and spectral properties, we conclude that the new source Swift J1728.9-3613 is a black hole X-ray binary.Comment: 6 figures, 2 tables, submitted in MNRA

    Evaluation of Lercanidipine in Paclitaxel-Induced Neuropathic Pain Model in Rat: A Preliminary Study

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    Objective. To demonstrate the antinociceptive effect of lercanidipine in paclitaxel-induced neuropathy model in rat. Materials and Methods. A total of 30 rats were divided into five groups of six rats in each group as follows: Gr I: 0.9% NaCl, Gr II: paclitaxel + 0.9% NaCl, Gr III: paclitaxel + lercanidipine 0.5 μg/kg, Gr IV: paclitaxel + lercanidipine 1 μg/kg, and Gr V: paclitaxel + lercanidipine 2.5 μg/kg. Paclitaxel-induced neuropathic pain in rat was produced by single intraperitoneal (i.p.) injection of 1 mg/kg of paclitaxel on four alternate days (0, 2, 4, and 6). The tail flick and cold allodynia methods were used for assessing the pain threshold, and the assessments were done on days 0 (before first dose of paclitaxel) and on days 7, 14, 21, and 28. Results. There was a significant decrease (P < 0.001) in the tail flick and cold allodynia latency in the paclitaxel-alone group from day 14 onward when compared with day 0. In the lercanidipine groups, the decrease in the tail flick and cold allodynia latency was not observed in 1.0 and 2.5 μg/kg groups and it was statistically significant (P < 0.01) when compared with paclitaxel-alone group
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