2,207 research outputs found

    Pengaruh Teknik Sintesis Terhadap Kualitas Produk Fattyamina Sekunder

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    Secondary fattyamines has been synthesized by reacting primary fatty amines with acylchlorides and continued with reducing the corresponding secondary fattyamides formed to secondary fattyamines using LiAIH<I'Fatty amines are raw material of natural-based surfactants that can be derived from fatty acids, olefins, or alcohols, of which can be synthesized from natural sources such as palm oil. Conversion of secondary fatty amides to secondary fatty amines was evaluated through the quality of FTIR spectra on wave number of 1639-1645 em' (C=O vibration) and 1544-1555 em" (vibrations of C-H and of secondary amine N-H). Method of synthesis by using closed reflux syncore reactor was better than those of using microwave teflon tubes, and open reflux. The yield of 9 different secondary fatty amines obtainedfrom 5 to 27 replicates by the closed reflux syncore reactor method varied from 17%to 96%

    Gravitational multi-NUT solitons, Komar masses and charges

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    Generalising expressions given by Komar, we give precise definitions of gravitational mass and solitonic NUT charge and we apply these to the description of a class of Minkowski-signature multi-Taub-NUT solutions without rod singularities. A Wick rotation then yields the corresponding class of Euclidean-signature gravitational multi-instantons.Comment: Some references adde

    Consequences of a covariant Description of Heavy Ion Reactions at intermediate Energies

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    Heavy ion collisions at intermediate energies are studied by using a new RQMD code, which is a covariant generalization of the QMD approach. We show that this new implementation is able to produce the same results in the nonrelativistic limit (i.e. 50MeV/nucl.) as the non-covariant QMD. Such a comparison is not available in the literature. At higher energies (i.e. 1.5 GeV/nucl. and 2 GeV/nucl.) RQMD and QMD give different results in respect to the time evolution of the phase space, for example for the directed transverse flow. These differences show that consequences of a covariant description of heavy ion reactions within the framework of RQMD are existing even at intermediate energies.Comment: LaTex-file, 28 pages, 8 figures (available upon request), accepted for publication in Physical Review

    Bird Movement Predicts Buggy Creek Virus Infection in Insect Vectors

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    Predicting the spatial foci of zoonotic diseases is a major challenge for epidemiologists and disease ecologists. Migratory birds are often thought to be responsible for introducing some aviozoonotic pathogens such as West Nile and avian influenza viruses to a local area, but most information on how bird movement correlates with virus prevalence is anecdotal or indirect. We report that the prevalence of Buggy Creek virus (BCRV) infection in cimicid swallow bugs (Oeciacus vicarius), the principal invertebrate vector for this virus, was directly associated with the likelihood of movement by cliff swallows (Petrochelidon pyrrhonota), an amplifying host for the virus, between nesting colonies. The prevalence of BCRV in bugs was also directly correlated with the number of swallows immigrating into a site. Birds that move into a site are often transient individuals that may have more often encountered virus elsewhere. These results indicate that the magnitude and direction of daily bird movement in a local area can accurately predict transmission foci for this virus and provide rare quantitative evidence that birds can play a critical role in the dispersal of certain vector-borne viruses

    Effective Values of Komar Conserved Quantities and Their Applications

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    We calculate the effective Komar angular momentum for the Kerr-Newman (KN) black hole. This result is valid at any radial distance on and outside the black hole event horizon. The effcetive values of mass and angular momentum are then used to derive an identity (Kχμ=2STK_{\chi^{\mu}}=2ST) which relates the Komar conserved charge (KχμK_{\chi^{\mu}}) corresponding to the null Killing vector (χμ\chi^{\mu}) with the thermodynamic quantities of this black hole. As an application of this identity the generalised Smarr formula for this black hole is derived. This establishes the fact that the above identity is a local form of the inherently non-local generalised Smarr formula.Comment: v3, minor modifications over v2; LaTex, 9 pages, no figures, to appear in Int. Jour. Theo. Phy

    Elementary particles, holography and the BMS group

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    In the context of asymptotically flat space-times, it has been suggested to label elementary particles as unitary irreducible representations of the BMS group. We analyse this idea in the spirit of the holographic principle advocating the use of this definition.Comment: 5 pages, revtex Several comments added, enhanced bibliograph

    Bird Movement Predicts Buggy Creek Virus Infection in Insect Vectors

    Get PDF
    Predicting the spatial foci of zoonotic diseases is a major challenge for epidemiologists and disease ecologists. Migratory birds are often thought to be responsible for introducing some aviozoonotic pathogens such as West Nile and avian influenza viruses to a local area, but most information on how bird movement correlates with virus prevalence is anecdotal or indirect. We report that the prevalence of Buggy Creek virus (BCRV) infection in cimicid swallow bugs (Oeciacus vicarius), the principal invertebrate vector for this virus, was directly associated with the likelihood of movement by cliff swallows (Petrochelidon pyrrhonota), an amplifying host for the virus, between nesting colonies. The prevalence of BCRV in bugs was also directly correlated with the number of swallows immigrating into a site. Birds that move into a site are often transient individuals that may have more often encountered virus elsewhere. These results indicate that the magnitude and direction of daily bird movement in a local area can accurately predict transmission foci for this virus and provide rare quantitative evidence that birds can play a critical role in the dispersal of certain vector-borne viruses
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