Electrochemical preparation of erythrosin and eosin

The paper highlights the preparation of erythrosin (tetra iodofluorescein) and eosin (tetra bromofluorescein) by electrolytic method at a graphite anode using a solution of sodium carbonate containing iodine and fluorescein for erythrosin and sodium bromide and fluorescein for eosin at a divided cell. The yield is compared with that of chemical method

Agricultural and biomedical application of Silver Nanoparticles synthesized by Halimeda gracilis Harvey ex J. Agardh

The present work is focused on the biosynthesis of the Silver (Ag) Nanoparticles using an aqueous extract of the green seaweed Halimeda gracilis. The visible colour change indicated the biosynthesis of Silver Nanoparticles and the specific peak produced within the UV-Vis spectrum confirmed the biosynthesis of Silver Nanoparticles. The possible functional groups were identified with Fourier Infrared Spectroscopy. The morphological characterization of biosynthesized Silver Nanoparticles was done by Scanning Electron Microscopy and Dynamic light scattering measurements and Zeta potential. The average size distribution of Ag-Nanoparticles were 295.9 (d.nm) and fairly stable with a zeta potential value of -28.6 mV. The size of biosynthesized Ag-Nanoparticles was also measured with X-ray diffraction assay. Due to agglomeration, the size difference of biosynthesized Ag-Nanoparticles in case of SEM and EDX occurred. The biosynthesized Ag-Nanoparticles were assayed for their antibacterial activity against some human pathogens and for their potential on seed germination of Abelmoschus esculentus and Raphanus sativus var. longipinnatus. The antibacterial activity of biosynthesized Ag Nanoparticles was the highest against Proteus mirabilis (2.33±0.2 cm), followed by Klebsiella pneumoniae, (1±0.0 cm). The effect of biosynthesized Ag-Nanoparticles on the seed germination of Raphanus sativus var. longipinnatus was excellent as the germination rate was 100 percent for Ag-Nanoparticles treated seeds, which was better than normal seaweed extract and seaweed liquid fertilizer treated seeds. The seed germination was also good for Abelmoschus esculentus with the treatment of seaweed mediated Ag-Nanoparticles as germination rate was 60 percent. This work proved that seaweed synthesized Ag-Nanoparticles are Phyto-friendly in nature and in future nano-bio fertilizer may be used as the growth promoter and eco-friendly Nano-bio-fertilizer

Entropy of semiclassical measures for nonpositively curved surfaces

We study the asymptotic properties of eigenfunctions of the Laplacian in the case of a compact Riemannian surface of nonpositive sectional curvature. We show that the Kolmogorov-Sinai entropy of a semiclassical measure for the geodesic flow is bounded from below by half of the Ruelle upper bound. We follow the same main strategy as in the Anosov case (arXiv:0809.0230). We focus on the main differences and refer the reader to (arXiv:0809.0230) for the details of analogous lemmas.Comment: 20 pages. This note provides a detailed proof of a result announced in appendix A of a previous work (arXiv:0809.0230, version 2

Delocalization of slowly damped eigenmodes on Anosov manifolds

We look at the properties of high frequency eigenmodes for the damped wave equation on a compact manifold with an Anosov geodesic flow. We study eigenmodes with spectral parameters which are asymptotically close enough to the real axis. We prove that such modes cannot be completely localized on subsets satisfying a condition of negative topological pressure. As an application, one can deduce the existence of a "strip" of logarithmic size without eigenvalues below the real axis under this dynamical assumption on the set of undamped trajectories.Comment: 28 pages; compared with version 1, minor modifications, add two reference

Some open questions in "wave chaos"

The subject area referred to as "wave chaos", "quantum chaos" or "quantum chaology" has been investigated mostly by the theoretical physics community in the last 30 years. The questions it raises have more recently also attracted the attention of mathematicians and mathematical physicists, due to connections with number theory, graph theory, Riemannian, hyperbolic or complex geometry, classical dynamical systems, probability etc. After giving a rough account on "what is quantum chaos?", I intend to list some pending questions, some of them having been raised a long time ago, some others more recent

Simulation study of phenol degradation by Fenton process using ASPEN-Plus

Present study deals with the simulation of the Fenton’s process for the removal of phenol using ASPEN-Plus. The effect of phenol concentration, catalyst loading, mole ratio of H2O2 to iron ion, and temperature on the phenol degradation rate has been studied using the developed process flow diagram. The result shows higher flow rate of hydrogen peroxide (4.2 kmol/h) favours phenol degradation (98%) since the hydroxyl radical availability rises. Increase in catalyst loading (186 g) and rise in mole ratio of hydrogen peroxide to iron ion (~1) improves the removal of phenol (~97%) from wastewater since the hydroxyl radical formation improves and thus affect the mechanism and chemical kinetics of Fenton reaction. Increase in temperature improves the degradation, however high temperature above optimum condition (32.5C) does not favour the degradation of phenol

Padina boergessenii ameliorates carbon tetrachloride induced nephrotoxicity in Wistar rats

AbstractThis research investigates the ameliorative effect of brown alga Padina boergessenii against CCl4-induced nephrotoxicity in rats. Twenty-four Wistar albino rats were divided into four groups as follows: control group (saline), CCl4 group, CCl4+P. boergessenii extract group and P. boergessenii extract alone group. At the end of the experimental period, the animals are sacrificed and tissue samples (kidney) were collected. CCl4 at a dose of 2mL/kg, administered subcutaneously, produced significantly decreased activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT). Histopathological examinations showed massive centrilobular necrosis and fat accumulation in CCl4-induced animals. In the protective test, especially in animals pretreated with P. boergessenii (150mg/kg) extract, there was a significant increase in antioxidant enzyme levels although there was no sign of abnormality in the kidney of rats pretreated with extract as evidenced by histopathological sections against CCl4-induced decrease of lipid peroxidation (TBARS). The ameliorative effect may be due to the presence of various bioactive compounds in alga. These results suggest that an extract of P. boergessenii is able to significantly alleviate the nephrotoxicity induced by CCl4 in Wistar rats

First record of Coelastrella vacuolata (Chlorophyta: Scenedesmaceae) in Tuticorin coast, Gulf of Mannar

Present study was aimed to isolate marine green algae from the sea water samples of Tuticorin coast, Gulf of Mannar. The collected seawater was maintained in Walne’s medium with optimum conditions (pH: 8.2-8.7, light intensity: 1000 Lux, salinity: 35 ppt and temperature: 18-25 °C and) for obtaining maximum growth. Then the mixed culture was purified by streak plate method and monoalgal sample was isolated. Monoalgal sample was identified as Coelastrella vacuolata by Light Microscope (LM), Fluorescent Microscope (FM) and Scanning Electron Microscope (SEM) based on its morphology. It was further confirmed by the molecular identification by 18s rDNA sequencing. Cells were observed either in isolated or in the colony and the size was ranged from 7 to 11 µ. It is the first record for the presence of C. vacuolata in the seawater of Tuticorin coast, Gulf of Mannar

Semiclassical measures and the Schroedinger flow on Riemannian manifolds

In this article we study limits of Wigner distributions (the so-called semiclassical measures) corresponding to sequences of solutions to the semiclassical Schroedinger equation at times scales $\alpha_{h}$ tending to infinity as the semiclassical parameter $h$ tends to zero (when $\alpha _{h}=1/h$ this is equivalent to consider solutions to the non-semiclassical Schreodinger equation). Some general results are presented, among which a weak version of Egorov's theorem that holds in this setting. A complete characterization is given for the Euclidean space and Zoll manifolds (that is, manifolds with periodic geodesic flow) via averaging formulae relating the semiclassical measures corresponding to the evolution to those of the initial states. The case of the flat torus is also addressed; it is shown that non-classical behavior may occur when energy concentrates on resonant frequencies. Moreover, we present an example showing that the semiclassical measures associated to a sequence of states no longer determines those of their evolutions. Finally, some results concerning the equation with a potential are presented.Comment: 18 pages; Theorems 1,2 extendend to deal with arbitrary time-scales; references adde

Fluorinated graphene oxide for enhanced S and X-band microwave absorption

Here we report the microwave absorbing properties of three graphene derivatives, namely, graphene oxide (GO), fluorinated GO (FGO, containing 5.6 at. % Fluorine (F)), and highly FGO (HFGO, containing 23 at. % F). FGO is known to be exhibiting improved electrochemical and electronic properties when compared to GO. Fluorination modifies the dielectric properties of GO and hence thought of as a good microwave absorber. The dielectric permittivities of GO, FGO, and HFGO were estimated in the S (2 GHz to 4 GHz) and X (8 GHz to 12 GHz) bands by employing cavity perturbation technique. For this, suspensions containing GO/FGO/HFGO were made in N-Methyl Pyrrolidone (NMP) and were subjected to cavity perturbation. The reflection loss was then estimated and it was found that −37 dB (at 3.2 GHz with 6.5 mm thickness) and −31 dB (at 2.8 GHz with 6 mm thickness) in the S band and a reflection loss of −18 dB (at 8.4 GHz with 2.5 mm thickness) and −10 dB (at 11 GHz with 2 mm thickness) in the X band were achieved for 0.01 wt. % of FGO and HFGO in NMP, respectively, suggesting that these materials can serve as efficient microwave absorbers even at low concentrations