8,175 research outputs found

    Biotransformation of indigo carmine to isatin sulfonic acid by lyophilized mycelia from Trametes versicolor

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    Indigo carmine (IC) was biotrasformed to 5-isatinsulfonic acid using intracellular and associated enzymes from Trametes versicolor lyophilized mycelia; even when extracellular enzymes were absent, in high concentration solutions of IC (4 000 mg L-1) and non-sterile condition. T. versicolor was grown in wheat strew and malt extract liquid medium and harvested during the stationary growth phase, it was lyophilized and made to react with indigo carmine. Experimental series were performed at different IC concentrations (from 100 to 4000 mg L-1). Color removal was 99.90, 98.75, 88.35, 79.47, 70.0 and 40.35% for 100, 500, 1000, 2000, 3000 and 4000 mg L-1 of IC, respectively after 120 h with exception for 100 mg L-1 of IC, which reached total color removal after 1 h. Reacted mixture byproducts were separated by column chromatography. IC biotransformation to 5-isatinsulfonic acid was confirmed by HPLC, UV-VIS, FT- IR, 1H and 13C NMR spectroscopy. Activity of laccase from lyophilized mycelia was conserved after one year at 4°C. Dehydrated biological material in colorant biodegradation is a new method which allows obtaining high discoloration efficiencies. Lyophilized mycelia could be more stable than traditionally used wet biomass or liquid culture for biodegradation of color dye.Key words: Biodegradation, indigo carmine, Trametes versicolor

    Synchronization of the Frenet-Serret linear system with a chaotic nonlinear system by feedback of states

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    A synchronization procedure of the generalized type in the sense of Rulkov et al [Phys. Rev. E 51, 980 (1995)] is used to impose a nonlinear Malasoma chaotic motion on the Frenet-Serret system of vectors in the differential geometry of space curves. This could have applications to the mesoscopic motion of biological filamentsComment: 12 pages, 7 figures, accepted at Int. J. Theor. Phy

    Tunable entanglement distillation of spatially correlated down-converted photons

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    We report on a new technique for entanglement distillation of the bipartite continuous variable state of spatially correlated photons generated in the spontaneous parametric down-conversion process (SPDC), where tunable non-Gaussian operations are implemented and the post-processed entanglement is certified in real-time using a single-photon sensitive electron multiplying CCD (EMCCD) camera. The local operations are performed using non-Gaussian filters modulated into a programmable spatial light modulator and, by using the EMCCD camera for actively recording the probability distributions of the twin-photons, one has fine control of the Schmidt number of the distilled state. We show that even simple non-Gaussian filters can be finely tuned to a ~67% net gain of the initial entanglement generated in the SPDC process.Comment: 12 pages, 6 figure

    1.5V fully programmable CMOS Membership Function Generator Circuit with proportional DC-voltage control

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    A Membership Function Generator Circuit (MFGC) with bias supply of 1.5 Volts and independent DC-voltage programmable functionalities is presented. The realization is based on a programmable differential current mirror and three compact voltage-to-current converters, allowing continuous and quasi-linear adjustment of the center position, height, width and slopes of the triangular/trapezoidal output waveforms. HSPICE simulation results of the proposed circuit using the parameters of a double-poly, three metal layers, 0.5 μm CMOS technology validate the functionality of the proposed architecture, which exhibits a maximum deviation of the linearity in the programmability of 7 %

    Inference of magnetic field strength and density from damped transverse coronal waves

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    A classic application of coronal seismology uses transverse oscillations of waveguides to obtain estimates of the magnetic field strength. The procedure requires information on the density of the structures. Often, it ignores the damping of the oscillations. We computed marginal posteriors for parameters such as the waveguide density; the density contrast; the transverse inhomogeneity length-scale; and the magnetic field strength, under the assumption that the oscillations can be modelled as standing magnetohydrodynamic (MHD) kink modes damped by resonant absorption. Our results show that the magnetic field strength can be properly inferred, even if the densities inside and outside the structure are largely unknown. Incorporating observational estimates of plasma density further constrains the obtained posteriors. The amount of information one is willing to include (a priori) for the density and the density contrast influences their corresponding posteriors, but very little the inferred magnetic field strength. The decision to include or leave out the information on the damping and the damping time-scales have a minimal impact on the obtained magnetic field strength. In contrast to the classic method which provides with numerical estimates with error bars or possible ranges of variation for the magnetic field strength, Bayesian methods offer the full distribution of plausibility over the considered range of possible values. The methods are applied to available datasets of observed transverse loop oscillations, can be extended to prominence fine structures or chromospheric spicules and implemented to propagating waves in addition to standing oscillations.Comment: 16 pages, A&A accepte
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