Browsing by Author "Kumar, Naresh"

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    A comparative study of chemically synthesized and Camellia sinensis leaf extract-mediated silver nanoparticles
    (3 Biotech, 2019) Kumar, Varun; Wadhwa, Ridhima; Kumar, Naresh; Maurya, Pawan Kumar
    Silver nanoparticles (AgNPs) are amongst the most fascinating nanomaterials which have been extensively synthesized by chemical reduction and biological method using enzymes, microorganisms and plant extracts. In our study, an aqueous extract of green tea was used as a stabilizing and reducing agent for AgNPs synthesis. The synthesized AgNPs were characterized by dynamic light scattering, UV–visible (UV–Vis) spectroscopy and scanning electron microscopy. These AgNPs were evaluated for antimicrobial activity and photocatalytic dye degradation. The AgNPs showed antibacterial activity against E. coli, S. aureus and S. pyogenes with 6 mm, 5 mm and 8 mm zone of inhibition, respectively. Our work also focused on methylene blue degradation in aqueous solution using AgNPs as catalyst which shows 65% of dye degradation. An absorbance peak of 427–437 nm was observed using UV–Vis spectrophotometer. Our study proves that the AgNPs show potent antimicrobial activity against pathogenic bacteria. At room temperature, AgNPs possess rapid, effective and steady catalytic activity in cationic organic dye degradation. The high catalytic activity of AgNPs can be employed in industries and water purification. Our study confirmed that green-synthesized AgNPs are eco-friendly and non-toxic.
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    Reinventing acquisition process of print books in university libraries
    (Annals of Library and Information Studies, 2022) Kumar, Naresh
    The paper aims to find the best practices of print book procurement in select central university libraries in northern India, including getting maximum discounts and supply of ordered books, and empanelling vendors. Through online questionnaires, selected libraries' book procurement procedures have been surveyed. Further, acquisition staff were consulted, and websites were accessed to learn book procurement procedures at central universities. Data collected from select seven university libraries were recorded in Microsoft Excel worksheets, aggregated, and summarized to create consolidated datasets for analysis. It is found that five universities buy books from empanelled vendors by setting minimum and maximum discount rates on print books. Vendors are increasingly being asked for discount quotes through expressions of interest. University libraries don't seem to buy books through tendering process or through government e-market place (GeM).