157 research outputs found

    On the Class of Exact Solutions of an Incompressible Second-order Fluid Flow by Creating Sinusoidal Disturbances

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    Exact solution of an incompressible fluid of second-order by causing disturbances in theliquid, which is initially at rest due to bottom oscillating sinusoidally, has been obtained in thisstudy. The results presented are in terms of nondimensional elasticoviscosity parameter ( )which depends on the non-Newtonian coefficient and the frequency of excitation of the externaldisturbance while considering the porosity (K) of the medium. The flow parameters are foundto be identical with that of Newtonian case as0 and K

    Flow of an Elastico-viscous Fluid Past an Infinite Platewith Variable Suction

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    Unsteady state flow of an incompressible elastico-viscous fluid of second-order type pastan infinite vertical porous flat plate by considering uniform and variable suction normal to theplate has been studied  and an exact solution is obtained for the velocity field. In the presentsituation, only two prescribed boundary conditions are available while the governing equationof motion is of third-order due to the presence of elastico-viscosity parameter.  The conceptfollowing Walters has been used for a much more meaningful solution.  The results for thevelocity distribution and skin friction have been analysed and discussed for different values ofthe parameters encountered in the governing equation of motion and skin friction on the plate.It is found that the effect of elastico-viscosity  and suction has significant contribution on thebackflow at the wal

    DETECTION OF PHISHING WEBSITES USING HYBRID MODEL

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    Online technologies have revolutionized the modern computing world. Thereare number of users who purchase products online and make payment through variouswebsites. There are multiple websites who ask user to provide sensitive data such asusername, password or credit card details etc. often for malicious reasons. This type ofwebsite is known as phishing website. The phishing website can be detected based on someimportant characteristics like URL (Uniform Resource Locator) and Domain identity.Several approaches have been proposed for detection of phishing websites by extracting thephishing data sets criteria to classify their legitimacy. However, there is no such approachthat can provide better results to the users from phishing attacks. This paper is an attemptto contribute in that area by presenting a hybrid model for classification to detect phishingwebsites with high accuracy and less error rate

    Exact Solutions of an Incompressible Fluid Flow of Second Order byForced Oscillations on the Porous Boundary

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    Exact solution of an incompressible fluid of second-order type  by causing forced oscillationsin the liquid of finite depth bounded by a porous bottom has been obtained.  The results presentedare in terms of nondimensional elastico-viscosity parameter () which depends on the non-Newtonian coefficient and the frequency of excitation () of the external disturbance whileconsidering the porosity (K) of the medium. The flow parameters are found to be identical withthat of  Newtonian case as  and K.  It is seen that the effect of  and the porosityof the bounding surface has significant effect on the velocity parameter.  Further, the nature ofthe paths of the fluid particles have also been studied with reference to  and the porosity ofthe bounding surface

    Rhodovulum aestuarii sp. nov., isolated from a brackish water body

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    A yellowish brown, phototrophic, purple non-sulfur bacterium, strain JA924r, was isolated in pure culture from a brackish water sample collected from an estuary. Single cells were oval to rod-shaped, non-motile and Gram-stain-negative and had a vesicu!ar architecture of intracellular photosynthetic membranes. Bacteriochlorophyll-a and carotenoids of the spheroidene series were present as photosynthetic pigments. Photolithoautotrophy, chemo-organoheterotrophy and photo-organoheterotrophy were the growth modes observed. Strain JA924T had complex growth requ1rements. Strain JA924 T was mesophilic and moderate!y halophilic. The DNA G -t- C content was 64 mal% (HPLC). The major cellular fatty acids were C18 1f·)7c/C 18 : 11·)6c, Ct 6 0 and C 18 . 0 . The major quinone was ubiquinone-1 0 (0-1 0). Phosphatidylg!ycerol, phosphatidylethanolamine, sulfolipid and an aminolipid were the main polar Iipids of strain JA924r. EzTaxon-e BLAST searches based on the 168 rRNA gene sequence of JA924T revealed highest similarity with Rhodovulum mangrovi AK41 T (98.19 %) and other members of the genus Rhodovulum (5 oc). Phenotypic, chemotaxonomic and molecular differences indicate that strain JA924 T represents a novel species of the genus Rhodovulum, for which the name Rhodovulum aestuarii sp. nov. is proposed. The type strain is JA924 T ( = LMG 29031 T = KCTC 15485 T)

    Rhodobium gokarnense sp. nov., a novel phototrophic alphaproteobacterium from a saltern

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    A pink-pigmented, phototrophic, purple nonsulfur bacterium, strain JA173T, was isolated in pure culture from a saltern in Gokarna, India, in a medium containing 2 % (w/v) NaCl. Strain JA173T was a non-motile Gram-negative rod that multiplied by budding. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JA173T clusters with the class Alphaproteobacteria; highest sequence similarity (98 %) was to the type strain of Rhodobium orientis and 94 % similarity was observed to the 16S rRNA gene sequence of the type strain of Rhodobium marinum. However, DNA–DNA hybridization with R. orientis DSM 11290T revealed a relatedness value of only 35.1 % with strain JA173T. Strain JA173T contained lamellar internal membranes, bacteriochlorophyll a and carotenoids of the spirilloxanthin series. Strain JA173T had an obligate requirement for NaCl (optimum growth at 2–6 %, w/v) and grew photoheterotrophically with a number of organic compounds as carbon source or electron donor. Photoautotrophic, chemoautotrophic and fermentative growth could not be demonstrated. Yeast extract was required for growth. Based on 16S rRNA gene sequence analysis, DNA–DNA hybridization data and morphological and physiological characteristics, strain JA173T is sufficiently different from other species of the genus Rhodobium to be recognized as a representative of a novel species, Rhodobium gokarnense sp. nov. The type strain is JA173T (=ATCC BAA-1215T=DSM 17935T=JCM 13532T)

    Rhodovulum visakhapatnamense sp. nov.

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    A Gram-negative, rod-shaped, phototrophic bacterium (JA181T) was isolated from a tidal water sample. On the basis of 16S rRNA gene sequence similarity, strain JA181T was shown to belong to the class Alphaproteobacteria, most closely related to Rhodovulum sulfidophilum (97.8 % similarity to the type strain), Rhodovulum adriaticum (93 %), Rhodovulum robiginosum (93 %), Rhodovulum iodosum (94 %), Rhodovulum imhoffii (94 %), Rhodovulum strictum (95 %), Rhodovulum euryhalinum (94.6 %) and Rhodovulum marinum (94.6 %). DNA–DNA hybridization with Rdv. sulfidophilum DSM 1374T (relatedness of 39 % with strain JA181T) and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain JA181T from the eight Rhodovulum species with validly published names. Strain JA181T therefore represents a novel species, for which the name Rhodovulum visakhapatnamense sp. nov. is proposed (type strain JA181T =JCM 13531T =ATCC BAA-1274T =DSM 17937T)

    Two novel species of marine phototrophic Gammaproteobacteria: Thiorhodococcus bheemlicus sp. nov. and Thiorhodococcus kakinadensis sp. nov.

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    Two coccoid phototrophic purple sulfur bacteria were isolated from marine habitats (marine aquaculture pond near Bheemli, Visakhapatnam and marine tidal waters from a fishing harbour, Kakinada) in a medium that contained 3 % NaCl (w/v). Strains JA132T and JA130T are Gram-negative, motile cocci with a single flagellum. Both have an obligate requirement for NaCl. Intracellular photosynthetic membranes are of the vesicular type. Bacteriochlorophyll a and most probably carotenoids of the spirilloxanthin series were present as photosynthetic pigments. Both strains were able to grow photolithoautotrophically and photolithoheterotrophically. Chemotrophic and fermentative growth could not be demonstrated. There is no vitamin requirement for strain JA132T, while strain JA130T requires niacin, biotin and pantothenate as growth factors. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that both strains cluster with species of the genus Thiorhodococcus belonging to the Gammaproteobacteria. The DNA G+C contents of strains JA132T and JA130T were 65.5 and 57.5 mol%, respectively. Based on the 16S rRNA gene sequence analysis, morphological and physiological characteristics, strains JA132T and JA130T are significantly different from each other and from other species of the genus Thiorhodococcus and are recognized as two novel species, for which the names Thiorhodococcus bheemlicus sp. nov. and Thiorhodococcus kakinadensis sp. nov. are proposed. The type strains of T. bheemlicus sp. nov. and T. kakinadensis sp. nov. are JA132T (=MTCC 8120T=ATCC BAA-1362T=JCM 14149T=DSM 18805T) and JA130T (=ATCC BAA-1353T=DSM 18858T=JCM 14150T), respectivel

    Thiohalocapsa marina sp. nov., from an Indian marine aquaculture pond

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    A spherical-shaped, phototrophic, purple sulfur bacterium was isolated in pure culture from anoxic sediment in a marine aquaculture pond near Bheemli (India). Strain JA142T is Gram-negative and non-motile. It has a requirement for NaCl (optimum of 2 % and maximum of 6 % w/v NaCl). Intracellular photosynthetic membranes are of the vesicular type. In vivo absorption spectra indicate the presence of bacteriochlorophyll a and carotenoids of the okenone series as photosynthetic pigments. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA142T is related to halophilic purple sulfur bacteria of the genera Thiohalocapsa and Halochromatium, with the highest sequence similarity to Thiohalocapsa halophila DSM 6210T (97.5 %). Morphological and physiological characteristics differentiate strain JA142T from other species of the genera Halochromatium and Thiohalocapsa. Strain JA142T is sufficiently different from Thiohalocapsa halophila based on 16S rRNA gene sequence analysis and morphological and physiological characteristics to allow the proposal of a novel species, Thiohalocapsa marina sp. nov., with the type strain JA142T (=JCM 14780T =DSM 19078T). The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain JA142T is AM491592. A phase-contrast micrograph of cells of strain JA142T, whole-cell and acetone absorption spectra and 16S rRNA gene sequence-based neighbour-joining, maximum-likelihood, minimum-evolution and maximum-parsimony trees are available as supplementary material with the online version of this paper

    Thiophaeococcus mangrovi gen. nov., sp. nov., a photosynthetic marine gammaproteobacterium isolated from Bhitarkanika mangrove forest, India

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    A coccoid, phototrophic purple sulfur bacterium was isolated in pure culture from a mud sample collected from brackish water in the Bhitarkanika mangrove forest of Orissa, India, in a medium containing 2 % NaCl (w/v). This bacterium, strain JA304T, was Gram-negative and had a requirement for NaCl. Intracellular photosynthetic membranes were of the vesicular type. The colour of the phototrophically grown culture was saddle-brown. Bacteriochlorophyll a and the carotenoid lycopene were present as photosynthetic pigments. Strain JA304T was able to grow photolithoautotrophically and could photoassimilate a number of organic substrates. Yeast extract was required for growth of strain JA304T. The DNA G+C content was 68.1–68.9 mol%. 16S rRNA gene sequence comparisons indicate that the isolate represents a member of the Chromatiaceae within the class Gammaproteobacteria. According to sequence comparison data, strain JA304T is positioned distinctly outside the group formed by the four genera Thiocystis, Chromatium, Allochromatium and Thermochromatium, with only 86.7–91.0 % sequence similarity. Distinct morphological, physiological and genotypic differences from these previously described taxa support the classification of this isolate as a representative of a novel species in a new genus, for which the name Thiophaeococcus mangrovi gen. nov., sp. nov. is proposed. The type strain of Thiophaeococcus mangrovi is JA304T (=JCM 14889T =DSM 19863T). PABA, para-aminobenzoic acid The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain JA304T is AM748925. A phase-contrast micrograph and whole-cell absorption spectrum and an acetone spectrum of extracted pigments of strain JA304T are available as supplementary material with the online version of this paper
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