1,305 research outputs found

    Levy statistical fluctuations from a Random Amplifying Medium

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    We report the studies of emission from a novel random amplifying medium that we term a ``Levy Laser'' due to the non-Gaussian statistical nature of its emission over the ensemble of random realizations. It is observed that the amplification is dominated by certain improbable events that are ``larger than rare'', which give the intensity statistics a Levy like ``fat tail''. This, to the best of our knowledge, provides the first experimental realization of Levy flight in optics in a random amplifying medium.Comment: 22 pages, 14 figures (postscript format

    EFFECT OF AQUEOUS EXTRACT OF CITRULLUS LANATUS PULP ON SCOPOLAMINE INDUCED COGNITIVE DYSFUNCTION IN SWISS ALBINO MICE

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    Objective: Amnesia is a medical condition involving the loss of memory. The memory loss is attributed to a number of illnesses or factors including Alzheimer’s disease (AD) and dementia, amnesia is often caused by head injury, brain trauma, or brain surgery. The incidence of amnesia affects only a small percent of the world’s population, the relevant study is becoming increasingly important with the rising numbers of people with AD. Alzheimer’s is predicted to strike 34 million people globally by 2025 and 14 million within the U.S. alone over subsequent 40 years. Methods: The study the possible protective effect of aqueous extract of Citrullus lanatus pulp (ACL) using scopolamine-induced amnesia in Swiss Albino mice. The mice were divided randomly into six groups each of five mice (n=5). Groups IV, V, and VI received mice feed and ACL 25%, 50%, and 100% instead of water for 21 days. Mice of Groups I, II, and III were treated with mice feed and water ad libitum. The animals were subjected to a single dose of scopolamine (1 mg/kg b.wt. ip) except in Group I on the 21st day 60 min after respective drug administration and observed for the effects in brain activity for the learning and memory. The behavioral parameters such as passive avoidance, Morris water maze, Y-Maze, and elevated plus maze were used as a tool for cognitive dysfunction study. Results: The ACL significantly reversed the scopolamine induced amnesia in mice. This is evident as C. lanatus is rich in lycopene content. The experimental models demonstrated that all the concentration of ACL treated mice showed remarkable results in restoring the effect of amnesia induced by scopolamine. Conclusion: To concise, these results suggest that ACL may exhibit protective effect on the brain to reverse the scopolamine induced amnesia. Further, it can be explored extracting the lycopene content of watermelon

    Design of a Secure Architecture for Last Mile Communication in Smart Grid Systems

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    AbstractEver increasing need of electricity has paved the need for Smart Grids. Smart Meters, digitalized networks and fault tolerant systems are the basic infrastructure which supports Smart Grid. Security in Smart Grid has become a major concern in the present scenario. In this paper we have proposed security architecture at the last mile distribution in Home Area Networks. A Secure communication architecture has been modeled which focuses on secure data transmission between the Smart Meters at home and Central Gateway at the utility centre. Hybrid Encryption algorithms and Digital Signature has been used to provide data integrity. The strength of the model has been verified with the help of an attacker and the model is found to resist attacks. The Encryption time and Decryption time of the cyptostack is lower when compared with other encryption algorithms

    Light scattering from a magnetically tunable dense random medium with weak dissipation : ferrofluid

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    We present a semi-phenomenological treatment of light transmission through and its reflection from a ferrofluid, which we regard as a magnetically tunable system of dense random dielectric scatterers with weak dissipation. Partial spatial ordering is introduced by the application of a transverse magnetic field that superimposes a periodic modulation on the dielectric randomess. This introduces Bragg scattering which effectively enhances the scattering due to disorder alone, and thus reduces the elastic mean free path towards Anderson localization. Our theoretical treatment, based on invariant imbedding, gives a simultaneous decrease of transmission and reflection without change of incident linear polarisation as the spatial order is tuned magnetically to the Bragg condition, namely the light wave vector being equal to half the Bragg vector (Q). Our experimental observations are in qualitative agreement with these results. We have also given expressions for the transit (sojourn) time of light and for the light energy stored in the random medium under steady illumination. The ferrofluid thus provides an interesting physical realization of effectively a "Lossy Anderson-Bragg" (LAB) cavity with which to study the effect of the interplay of spatial disorder, partial order and weak dissipation on light transport. Given the current interest in propagation, optical limiting and storage of light in ferrofluids, the present work seems topical

    IN VITRO ANTIOXIDANT ACTIVITY OF ETHANOLIC EXTRACT OF TERMINALIA CATAPPA LEAVES

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    Objectives: Free radicals are the important role in causing various kinds of diseases. Free radicals neutralized with the help of antioxidants, so the aimof this study is to find out the antioxidant potential of ethanolic extract of Terminalia catappa Linn. leaves by in vitro models.Methods: The plant material is collected, authenticated, dried, and grind into powder. The powdered plant material is subjected to successivelySoxhlet extraction with a solvent of ethanol. Ethanol extract of leaves were taken and the extract is subjected to reducing power assay, H assay,nitric oxide assay, and 2,2-diphenylpicrylhydrazyl (DPPH) assay by using standardized methods.Results: The results of all the assays proved that the ethanolic extract of T. catappa has an antioxidant potential on a dose-dependent manner. Thehighest percentage of reducing power (78.04%) is recorded at 500 μg/ml, 500 µg/ml have a (56.4%) of scavenging activity, (74.68%) activity ofnitrous oxide production and DPPH percentage of inhibition is (99.6%). The results were compared with the antioxidant activity of standard ascorbicacid.Conclusion: The study proves that the ethanolic extract of T. catappa leaves is a good source of antioxidants, and future medicated world choose thisphytochemical constituent rich plant for their drug preparation after the deepness of research. In all the methods the plant leaves has been found topossess the antioxidant activity. which may be the responsible for various therapeutic properties. The current study showing that T.catappa is havinghigh quantity of phytochemicals and a worthy source of natural antioxidants. Using this kind of herbal medicine we can lead the life with harmlessdrug for harmful illness.Keywords: Terminalia catappa, Reducing power assay, Hydrogen peroxide assay, Nitric oxide assay and 2-2-diphenyl-1-picrylhydrazylassay

    Markovian embedding of nonlocal equations using spectral representation

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    Nonlocal evolutionary equations containing memory terms model a variety of non-Markovian processes. We present a Markovian embedding procedure for a class of nonlocal equations by utilising the spectral representation of the nonlinear memory kernel. This allows us to transform the nonlocal system to a local-in-time system in an abstract extended space. We demonstrate our embedding procedure and its efficacy for two different physical models, namely the (i) 1D walking droplet and (ii) the 1D single-phase Stefan problem

    Coherent forecasting of NoGeAR(1) model

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    This article focuses on the coherent forecasting of the recently introduced novel geometric AR(1) (NoGeAR(1)) model - an INAR model based on inflated - parameter binomial thinning approach. Various techniques are available to achieve h - step ahead coherent forecasts of count time series, like median and mode forecasting. However, there needs to be more body of literature addressing coherent forecasting in the context of overdispersed count time series. Here, we study the forecasting distribution corresponding to NoGeAR(1) process using the Monte Carlo (MC) approximation method. Accordingly, several forecasting measures are employed in the simulation study to facilitate a thorough comparison of the forecasting capability of NoGeAR(1) with other models. The methodology is also demonstrated using real-life data, specifically the data on CW{\ss} TeXpert downloads and Barbados COVID-19 data
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