4,601 research outputs found

    Spelter Pan - Design, Heating Systems and Operations

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    This is decided by the shape of article to be galvanized. It should be possible to immerse and withdraw articles without much agitation of the bath. The pans for wire, tube, strip, fasteners, have suitable designs to take care of this factor

    Probing large distance higher dimensional gravity from lensing data

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    The modifications induced in the standard weak-lensing formula if Newtonian gravity differs from inverse square law at large distances are studied. The possibility of putting bounds on the mass of gravitons from lensing data is explored. A bound on graviton mass, esitmated to be about 100 Mpc1^{-1} is obtained from analysis of some recent data on gravitational lensing.Comment: 6 pages, 1 figure, added reference

    Study of one-dimensional nature of (Sr,Ba)_2Cu(PO_4)_2 and BaCuP_2O_7 via 31P NMR

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    The magnetic behavior of the low-dimensional phosphates (Sr,Ba)_2 Cu(PO_4)_2 and BaCuP_2O_7 was investigated by means of magnetic susceptibility and ^{31}P nuclear magnetic resonance (NMR) measurements. We present here the NMR shift K(T), the spin-lattice 1/T_1 and spin-spin 1/T_2 relaxation-rate data over a wide temperature range 0.02 K < T < 300 K. The T-dependence of the NMR K(T) is well described by the S=1/2 Heisenberg antiferromagnetic chain model with an intrachain exchange of J/k_B = 165 K, 151 K, and 108 K in Sr_2Cu(PO_4)_2, Ba_2Cu(PO_4)_2, and BaCuP_2O_7, respectively. Our measurements suggest the presence of magnetic ordering at 0.8 K in BaCuP_2O_7 (J/k_B = 108 K). For all the samples, we find that 1/T_1 is nearly T-independent at low-temperatures (1 K < T < 10 K), which is theoretically expected for 1D chains when relaxation is dominated by fluctuations of the staggered susceptibility. At high temperatures, 1/T_1 varies nearly linearly with temperature

    Detection of early osteogenic commitment in primary cells using Raman spectroscopy

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    Major challenges in the development of novel implant surfaces for artificial joints include osteoblast heterogeneity and the lack of a simple and sensitive in vitro assay to measure early osteogenic responses. Raman spectroscopy is a label-free, non-invasive and non-destructive vibrational fingerprinting optical technique that is increasingly being applied to detect biochemical changes in cells. In this study Raman spectroscopy has been used to obtain bone cell-specific spectral signatures and to identify any changes therein during osteoblast commitment and differentiation of primary cells in culture. Murine calvarial osteoblasts (COBs) were extracted and cultured and studied by Raman spectroscopy over a 14 day culture period. Distinct osteogenic Raman spectra were identified after 3 days of culture with strong bands detected for mineral: phosphate ν3 (1030 cm−1) and B-type carbonate (1072 cm−1), DNA (782 cm−1) and collagen matrix (CH2 deformation at 1450 cm−1) and weaker phosphate bands (948 and 970 cm−1). Early changes were detected by Raman spectroscopy compared to a standard enzymatic alkaline phosphatase (ALP) assay and gene expression analyses over this period. Proliferation of COBs was confirmed by fluorescence intensity measurements using the Picogreen dsDNA reagent. Changes in ALP levels were evident only after 14 days of culture and mRNA expression levels for ALP, Col1a1 and Sclerostin remained constant during the culture period. Sirius red staining for collagen deposition also revealed little change until day 14. In contrast Raman spectroscopy revealed the presence of amorphous calcium phosphate (945–952 cm−1) and carbonated apatite (957–962 cm−1) after only 3 days in culture and octacalcium phosphate (970 cm−1) considered a transient mineral phase, was detected after 5 days of COBs culture. PCA analysis confirmed clear separation between time-points. This study highlights the potential of Raman spectroscopy to be utilised for the early and specific detection of proliferation and differentiation changes in primary cultures of bone cells

    31P NMR study of Na2CuP2O7: a S=1/2 two-dimensional Heisenberg antiferromagnetic system

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    The magnetic properties of Na2CuP2O7 were investigated by means of 31P nuclear magnetic resonance (NMR), magnetic susceptibility, and heat capacity measurements. We report the 31P NMR shift, the spin-lattice 1/T1, and spin-spin 1/T2 relaxation-rate data as a function of temperature T. The temperature dependence of the NMR shift K(T) is well described by the S=1/2 square lattice Heisenberg antiferromagnetic (HAF) model with an intraplanar exchange of J/k_B \simeq 18\pm2 K and a hyperfine coupling A = (3533\pm185) Oe/mu_B. The 31P NMR spectrum was found to broaden abruptly below T \sim 10 K signifying some kind of transition. However, no anomaly was noticed in the bulk susceptibility data down to 1.8 K. The heat capacity appears to have a weak maximum around 10 K. With decrease in temperatures, the spin-lattice relaxation rate 1/T1 decreases monotonically and appears to agree well with the high temperature series expansion expression for a S = 1/2 2D square lattice.Comment: 12 pages, 8 figures, submitted to J. Phys.: Cond. Ma

    Phenol as a Non-aqueous Solvent

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    1017-101

    Antimicrobial susceptibility pattern of bacterial isolates in patients of chronic suppurative otitis media in a tertiary care hospital in India

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    Background: Chronic suppurative otitis media (CSOM) is a massive public health problem in developing countries like India, especially among low socio-economic class because of malnutrition, overcrowding, poor hygiene, inadequate health care and recurrent upper respiratory tract infections. CSOM cases unless managed effectively may land into various complications such as persistent otorrhoea, hearing impairment, mastoiditis, labyrinthitis, facial nerve paralysis to more serious intracranial abscesses.Methods: The study was carried out in a tertiary care hospital from January 2017 to December 2017 with an aim to determine the microbiological profile of ear discharge in patients suffering from CSOM and their antimicrobial susceptibility pattern using Kirby Bauer disc diffusion method.Results: Out of 630 samples processed, 407 (64.6%) samples were culture positive. Most common organism isolated was Pseudomonas spp. (43.2%) followed by S. aureus (39.1%). Most of isolates recovered were multidrug resistant.Conclusions: Management of CSOM consists mainly of eradicating infection and closure of tympanic membrane. Periodic monitoring of bacterial isolates and their antibiotic susceptibility pattern is necessary for administering appropriate antibiotics as empirical treatment and also helps in reducing the potentially disabling and fatal complications of CSOM
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