6,030 research outputs found

    Indian seas: a megadiversity hotspot

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    Marine biological research in India dates back to the 18th century, and the surveys and expeditions conducted by Europeans, particularly the British. The most notable among these pioneers were great naturalists such as Francis Day (1829-1889) , Nelson Annandale (1876-1924) and Herbert Robinson (1874-1929) who worked during the latter part o f the 19th century and early 20th century. This foundation helped India to create a network o f marine research laboratories in government funded institutions and universities all along the coastline

    Applicability of a Representation for the Martin's Real-Part Formula in Model-Independent Analyses

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    Using a novel representation for the Martin's real-part formula without the full scaling property, an almost model-independent description of the proton-proton differential cross section data at high energies (19.4 GeV - 62.5 GeV) is obtained. In the impact parameter and eikonal frameworks, the extracted inelastic overlap function presents a peripheral effect (tail) above 2 fm and the extracted opacity function is characterized by a zero (change of sign) in the momentum transfer space, confirming results from previous model-independent analyses. Analytical parametrization for these empirical results are introduced and discussed. The importance of investigations on the inverse problems in high-energy elastic hadron scattering is stressed and the relevance of the proposed representation is commented. A short critical review on the use of Martin's formula is also presented.Comment: Two comments and one reference added at the end of Subsec. 3.3; 23 pages, 9 figures; to be published in Int. J. Mod. Phys.

    Xenobiotic induced functional alterations in Hepatopancreas of the Penaeid shrimp Metapenaeus dobsoni (Miers)

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    Xenobiocic-induced imbalance between production and ulilisation of cylosolic lipid provides biochemical evidence of structural and functional alaerations in animal tissues . The present study investigates metal induced accumulalion of unsaturated neutral lipid inthe hepatopancreas of the penaei

    Effect of sublethal copper on growth efficiency of the shrimp Metapenaeus dobsoni (Miere)

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    In this investigation, an attempt is made to elucidate the effect of copper sublethal concentrations, on the energy conversion and growth efficiency of a commercially important Penaeid shrimp Metapenaeus dobsoni (Miere

    Doping, density of states and conductivity in polypyrrole and poly(p-phenylene vinylene)

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    The evolution of the density of states (DOS) and conductivity as function of well controlled doping levels in OC_1C_10-poly(p-phenylene vinylene) [OC_1C_10-PPV] doped by FeCl_3 and PF_6, and PF_6 doped polypyrrole (PPy-PF_6 have been investigated. At a doping level as high as 0.2 holes per monomer, the former one remains non-metallic, while the latter crosses the metal-insulator transition. In both systems a similar almost linear increase in DOS as function of charges per unit volume c* has been observed from the electrochemical gated transistor data. In PPy-PF_6, when compared to doped OC_1C_10-PPV, the energy states filled at low doping are closer to the vacuum level; by the higher c* at high doping more energy states are available, which apparently enables the conduction to change to metallic. Although both systems on the insulating side show log(sigma) proportional to T^-1/4 as in variable range hopping, for highly doped PPy-PF_6 the usual interpretation of the hopping parameters leads to seemingly too high values for the density of states.Comment: 4 pages (incl. 6 figures) in Phys. Rev.

    Settlement pattern of the larvae of Hydroides elegans (Polychaeta) in the presence of petroleum hydrocarbon compounds

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    Polyaromatic hydrocarbons (PAHs) have been recognised as the main toxic components of crude oil polluting the manne environment. The larvae of invertebrates, including polychaetes, are more susceptible to toxicants in the environment. The effect of different concentrations of water accommodated hydrocarbons on survival and settlement of Hydroides elegans (Haswell) was studied in the laboratory. A parallel study of the settlement pattern In the field were conducted using terra-cotta tiles. The dissolved / dispersed hydrocarbon concentration in the chosen area of Cochin harbour was mOnItored dunng the study period. The presence of PAHs in high concentrations was observed to have an adverse effect on the settlement of the larvae of Hydroides elegans

    Limits on monopole fluxes from KFG experiment

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    The nucleon decay experiment at KGF at a depth of 2.3 Km is eminently suited for the search of Grand Unified theory (GUT) monopoles, whose velocities at the present epoch are predicted to be around 0.001C. At this depth the cosmic ray background is at a level 2/day in the detector of size 4m x 6m x 3.7m and one can look for monopoles traversing the detector in all directions, using three methods, i.e., (1) dE/dx (ionization); (2) time of flight and (3) catalysis of nucleon decay. The detector is composed of 34 layers of proportional counters arranged in horizontal planes one above the other in an orthogonal maxtrix. Each of the 1594 counters are instrumented to measure ionization in the gas (90% Argon + 10% Methane) as well as the time of arrival of particles

    Distribution and abundance of the genus Vinciguerria (Gonostomatidae) in the DSL of Indian EEZ with a note on the biology of Vinciguerria nimbaria

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    In the DSL fish biomass one of the dominant genus was Vinciguerria, represented by three species such as V. nimbaria, V. attenuata and V. poweriae. The occurrence of Vinciguerria was frequent in nortliwest and southwest area of EEZ at varying depths. The average number per haul in Isaac Kidd mid water trawl (IKMT) was 149 in day and 191 in night collection. Vinciguerria nimbaria has accounted for more than 95% of the total catch of the genus. Its total length varied from 10-56 mm. The length weight relationship is log W = -5.5691 + 3.1676 log I. Invariably the species fed on copepods, ostracods, cladocerans, appendicularians euphausiids, chaetognaths, fish larvae etc. with variations in feeding intensity during day and night. About 92 % of the catch belonged to mature fishes. The species spawns only once in a year and the fecundity ranged from 140 to 770 ova in fishes of 34 - 55 mm total length

    A quantitative evaluation of metallic conduction in conjugated polymers

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    As the periodicity in crystalline materials creates the optimal condition for electronic delocalization, one might expect that in partially crystalline conjugated polymers delocalization is impeded by intergrain transport. However, for the best conducting polymers this presumption fails. Delocalization is obstructed by interchain rather than intergrain charge transfer and we propose a model of weakly coupled disordered chains to describe the physics near the metal-insulator transition. Our quantitative calculations match the outcome of recent broad-band optical experiments and provide a consistent explanation of metallic conduction in polymers.Comment: 4 pages incl. 3 figure
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