14 research outputs found

    Effect of PVP Intermediate Layer on the Properties of SAPO 34 Membrane

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    SAPO 34 zeolite membranes were prepared on a tubular mullite support. Before membrane preparation, the support surfaces were coated with seed crystals. Seeds particles were prepared by hydrothermal synthesis. Before seeding, the substrates were treated with polyvinylpyrrolidone (PVP) to orient the seeds. Both the treated and untreated supports were seeded, and membranes were synthesized on those support tubes by ex situ hydrothermal method. The PVP molecule exists in the two resonance structures. Hence the acylamino bond –N+ = C–O-– acts as intermediate linker between support surface and seed surface. Due to charge interaction, the seed crystals were anchored strongly to support surface. The synthesized membranes along with seed crystals were characterized by XRD, FESEM, and EDAX analysis. The single-gas permeation with CO2 and H2 was investigated. Up to 5 bar of feed pressure, the permselectivity of CO2 and H2 was as high as 4.2

    An incremental clustering of gene expression data

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    Abstract-This paper presents an incremental clustering algorithm based on DGC, a density-based algorithm we developed earlier [1]. We experimented with real-life datasets and both methods perform satisfactorily. The methods have been compared with some well-known clustering algorithms and they perform well in terms of z-score cluster validity measure

    Horizontal vs. Vertical Partitioning in Association Rule Mining: A Comparison

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    Association rules identify associations among data items and were introduced in [1,2,3]. There are useful rule mining algorithms [4] based on the horizontal partitioning approach. These algorithms partition the database and find frequent itemsets in each partition, and combine the itemsets in each partition to get the global candidate itemsets as well as the global support for the items. In this paper, a novel rule mining algorithm has been presented based on vertical partitioning approach. To establish the superiority of the algorithm in comparison to [4], it also includes experimental results. 1

    Molecular aspects of core shell intrinsic defect induced enhanced antibacterial activity of ZnO nanocrystals

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    Aim: To investigate molecular aspects of the antibacterial effect of size-dependent core-shell intrinsic defects of nanocrystalline ZnO synthesized through high energy ball milling technique. Materials & methods: Mechanically synthesized and characterized 7, 10 and 15 h milled ZnO nanoparticles were evaluated for antibacterial activity with molecular investigation by computational molecular docking. Results: Synthesized ZnO nanoparticles displayed shrinkage of core and increase of shell with reduction in size of bulk ZnO particles from 250 to 80, 40 and 20 nm and increase in zeta potential up to -19 mV in 7, 10 and 15 h nano ZnO. Antibacterial activity was found increased with decrease in size due to increased reactive oxygen species andmembrane damage in bacteria. Conclusion: Synthesized nano ZnO exhibit size-dependent antibacterial action as consequences of interactions with cell membrane proteins via hydrogen bond interaction with amino acid residues followed by internalization, membrane depolarization and induction of reactive oxygen species generation

    Ag-TiO2 Nanoparticle Codoped SiO2 Films on ZrO2 Barrier-Coated Glass Substrates with Antibacterial Activity in Ambient Condition

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    ABSTRACT Anatase TiO2 and Ag nanoparticles (NPs) codoped SiO2 films were prepared by the sol-gel method. Proportionate amounts of 3-(glycidoxypropyl)trimethoxysilane (GLYMO), tetraethylorthosilicate (TEOS) and 3-(methacryloxypropyl)trimethoxysilane (MEMO) derived inorganic-organic silica sol, commercially available dispersed anatase TiO2 NPs, and AgNO3 were used to prepare the sols. The films were prepared on ZrO2 (cubic) precoated soda-lime glass substrates by a single-dipping technique and heat-treated at 450 °C in air and H2/Ar atmosphere to obtain hard, relatively porous, and transparent coatings of thickness >600 nm. The ZrO2 barrier layer was previously applied on soda-lime glass to restrict the diffusion of Ag into the substrate. The Ag-TiO2 NPs incorporated SiO2 films were intense yellow in color and found to be fairly stable at ambient condition for several days under fluorescent light. These films show a considerable growth inhibition on contact with the gram negative bacteria E. coli
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