1,180 research outputs found

    Modeling stochastic hybrid systems

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    Optimizing chlorophyll meter (SPAD) reading to allow efficient nitrogen use in rice and wheat under rice-wheat cropping system in eastern India

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    Conventional agricultural practices that rely heavily on blanket fertilizer recommendation, eventually leading to deteriorated partial factor productivity and N use efficiency. We investigated the effect of SPAD-based N-management on productivity and N use efficiency of rice and wheat in eastern India. Here, in the experiment three SPAD thresholds (34, 36 and 38 in rice and 38, 40 and 42 in wheat) using three N levels (15, 25 and 35 kg N ha−1) in split were incorporated as real-time N management (RTNM), one fixed-time N management (FTNM), farmers’ fertilizer practice (FFP) and control (No fertilizer) were introduced in wet and dry seasons for rice and wheat, respectively, during the years 2010 to 2012. Topdressing with 25 kg N ha−1 at medium SPAD (S36 in rice and S40 in wheat) increased soil N availability, leaf N content and grain yield of rice (5215 kg ha−1) and wheat (4483 kg ha−1) over the grain yield recorded under a low rate of N topdressing at low SPAD. While saving 33.3% N in rice and 18.8% N in wheat, the agronomic N use efficiency (58.5% in both rice and wheat) and nitrogen recovery efficiency (32.2% in rice and 15.1% in wheat) can be increased when compared with conventional FTNM. The SPAD-based management strategy showed great promise in efficient management of N fertilizer, and we estimated the optimal SPAD threshold for rice and wheat as 37.5 and 41.8, respectively

    Quantum corrections to the entropy of charged rotating black holes

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    Hawking radiation from a black hole can be viewed as quantum tunneling of particles through the event horizon. Using this approach we provide a general framework for studying corrections to the entropy of black holes beyond semiclassical approximations. Applying the properties of exact differentials for three variables to the first law thermodynamics, we study charged rotating black holes and explicitly work out the corrections to entropy and horizon area for the Kerr-Newman and charged rotating BTZ black holes. It is shown that the results for other geometries like the Schwarzschild, Reissner-Nordstr\"{o}m and anti-de Sitter Schwarzschild spacetimes follow easily

    A note on an LQG regulator with Markovian switching and pathwise average cost

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    Physiological Responses of Salvinia natans L. to Aluminium Stress and Its Interaction with Putrescine

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    Salvinia natans L. a water fern is displayed with some of its physiological attributes in response to aluminium (Al) stress in aqua culture as well as its interaction with externally applied putrescine (put). At the tissue level the Al deposition is prominent and mostly distributed in the intracellular spaces as well as cellular interfaces. The accumulation of Al and its induced oxidative damages are also revealed through Evan’s blue staining. In both the cases dose dependent responses of Al induced oxidative damages and its mitigation with Put was the resultant. Under non enzymatic antioxidation pathways, anthocyanin and flavonoids were the two phenolics over expressed as a function of Al and ameliorated with Put application. The property of root membranes was changed with an up regulation of H+/ATPase activity which was moderated by Put.The peroxidase activity particularly those were restricted to the wall bound also showed variability according to Al doses as revealed through in gel staining. From these studies of Al accumulation and its concomitant changes in physiological attributes in Salvinia plants, the species could be selected as a potential hyper accumulator of Al. The role of Put in Al accumulation as well as its moderation has been discussed with reference to physiological activities

    Time-reversal symmetry breaking in the noncentrosymmetric Zr3Ir superconductor

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    We report the discovery of Zr3Ir as a structurally different type of unconventional noncentrosymmetric superconductor (with Tc=2.3 K), here investigated mostly via muon-spin rotation/relaxation (μSR) techniques. Its superconductivity was characterized using magnetic susceptibility, electrical resistivity, and heat capacity measurements. The low-temperature superfluid density, determined via transverse-field μSR and electronic specific heat, suggests a fully gapped superconducting state. The spontaneous magnetic fields, revealed by zero-field μSR below Tc, indicate the breaking of time-reversal symmetry in Zr3Ir and hence the unconventional nature of its superconductivity. By using symmetry arguments and electronic-structure calculations we obtain a superconducting order parameter that is fully compatible with the experimental observations. Hence, our results clearly suggest that Zr3Ir represents a structurally different member of noncentrosymmetric superconductors with broken time-reversal symmetry

    Elevated serum ceruloplasmin levels are associated with higher impulsivity in people with Parkinson’s Disease

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    Background. Heightened impulsivity has been reported in a subset of people with Parkinson’s disease (PwP) and is considered a risk factor for the development of impulse control disorders (ICDs). However, at present, there are no recognised biochemical markers of heightened impulsivity. Objectives. To determine if ceruloplasmin, a serum marker involved in the regulation of iron and copper homeostasis, is associated with trait impulsivity in PwP. Methods. The study measured serum ceruloplasmin and impulsivity using the Barratt Impulsiveness Scale (BIS-11) in an Australian cohort of 214 PwP. Multivariate general linear models (GLMs) were used to identify whether higher serum ceruloplasmin levels (>75th percentile) were significantly predictive of BIS-11 scores. Results. Serum ceruloplasmin was higher in females with PD (p<0.001) and associated with MDS-UPDRS III, Hoehn and Yahr, and ACE-R scores (p<0.05). When correcting for covariates, higher serum ceruloplasmin concentrations were associated with the 2nd order nonplanning impulsivity and with the 1st order self-control and cognitive complexity impulsivity domains. Conclusions. Higher serum ceruloplasmin levels are independently associated with heightened nonplanning impulsivity in PwP. Thus, serum ceruloplasmin levels may have clinical utility as a marker for heightened impulsivity in PD

    Thermodynamics Inducing Massive Particles' Tunneling and Cosmic Censorship

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    By calculating the change of entropy, we prove that the first law of black hole thermodynamics leads to the tunneling probability of massive particles through the horizon, including the tunneling probability of massive charged particles from the Reissner-Nordstr\"om black hole and the Kerr-Newman black hole. Novelly, we find the trajectories of massive particles are close to that of massless particles near the horizon, although the trajectories of massive charged particles may be affected by electromagnetic forces. We show that Hawking radiation as massive particles tunneling does not lead to violation of the weak cosmic-censorship conjecture

    Remarks on 't Hooft's Brick Wall Model

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    A semi-classical reasoning leads to the non-commutativity of the space and time coordinates near the horizon of Schwarzschild black hole. This non-commutativity in turn provides a mechanism to interpret the brick wall thickness hypothesis in 't Hooft's brick wall model as well as the boundary condition imposed for the field considered. For concreteness, we consider a noncommutative scalar field model near the horizon and derive the effective metric via the equation of motion of noncommutative scalar field. This metric displays a new horizon in addition to the original one associated with the Schwarzschild black hole. The infinite red-shifting of the scalar field on the new horizon determines the range of the noncommutativ space and explains the relevant boundary condition for the field. This range enables us to calculate the entropy of black hole as proportional to the area of its original horizon along the same line as in 't Hooft's model, and the thickness of the brick wall is found to be proportional to the thermal average of the noncommutative space-time range. The Hawking temperature has been derived in this formalism. The study here represents an attempt to reveal some physics beyond the brick wall model.Comment: RevTeX, 5 pages, no figure

    Hybrid stars with the color dielectric and the MIT bag models

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    We study the hadron-quark phase transition in the interior of neutron stars (NS). For the hadronic sector, we use a microscopic equation of state (EOS) involving nucleons and hyperons derived within the Brueckner-Bethe-Goldstone many-body theory, with realistic two-body and three-body forces. For the description of quark matter, we employ both the MIT bag model with a density dependent bag constant, and the color dielectric model. We calculate the structure of NS interiors with the EOS comprising both phases, and we find that the NS maximum masses are never larger than 1.7 solar masses, no matter the model chosen for describing the pure quark phase.Comment: 11 pages, 5 figures, submitted to Phys. Rev.
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