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61.
Yenagi J Arlikatti NV Tonannavar J 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,77(5):1025-1033
Ab initio conformers and dimers have been computed at RHF and B3LYP/6-31G* levels for isomers 2-chloro-3-hydroxybenzaldehyde and 3-chloro-4-hydroxybenzaldehyde to explain the observed infrared absorption and Raman vibrational spectral features in the region 3500-50 cm(-1). The position of the chlorine in ortho position with respect to aldehyde group in 2-chloro-3-hydroxybenzaldehyde yields four distinct conformers; whereas the chlorine in meta position in 3-chloro-4-hydroxybenzaldehyde yields effectively only three conformers. Major spectral features as strong absorptions near 3160-80 cm(-1), down-shifting of the aldehydic carbonyl stretching mode and up-shifting of hydroxyl group's in-plane bending mode are explained using ab initio evidence of O-H?O bond-aided dimerization between the most stable conformers of each molecule. Absorption width of about 700 cm(-1) (~8.28 kJ/mol) of O-H stretching modes suggests a strong hydrogen bonding with the ab initio bond lengths, O-H?O in the range of 2.873-2.832 ?. A strong Raman mode near 110-85 cm(-1) in each molecule is interpreted to be coupled vibrations of pseudo-dimeric trans and cis structures. 相似文献
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Bimlesh Lochab Indra K. Varma Jayashree Bijwe 《Journal of Thermal Analysis and Calorimetry》2010,102(2):769-774
A novel benzoxazine monomer (Bz-C) based on agrochemical renewable resource—cardanol (by-product of cashew nut tree, Anacardium occidentale) was synthesized. Bz-C, a liquid monomer, was used as reactive diluent for the solventless synthesis of bisphenol-A benzoxazine
monomer (Bz-A). Benzoxazine monomer based on cardanol and bisphenol-A in 3:1, 1:1 and 1:3 blend ratio were prepared by this
method. The resins had Brookfield viscosity at 316 K in the range of 145–81,533 mPa s. The resins were characterized by 1H-NMR, FTIR and elemental analysis. Curing characteristics were studied by DSC analysis. Thermal stability of cured resins
was found to improve with increase in Bz-C content in the blends. 相似文献
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Jayashree A. Dharmadhikari Rucha A. Deshpande Arpita Nath Krithika Dota Deepak Mathur Aditya K. Dharmadhikari 《Applied physics. B, Lasers and optics》2014,117(1):471-479
We experimentally investigate the spectral extent and spectral profile of the supercontinuum (SC) generated in transparent solids: barium fluoride, calcium fluoride, and fused silica upon irradiation by intense femtosecond-long pulses of 800, 1,380, and 2,200 nm light. These wavelengths correspond to the normal and anomalous group velocity dispersion (GVD) regimes in fused silica calcium fluoride and barium fluoride. We observe an isolated (anti-Stokes) wing on the blue side most prominently in fused silica but also in CaF2. The SC conversion efficiency is measured for the long wavelengths used in our experiments. We also present results on filamentation in BaF2 in the anomalous GVD regime, including visualization of focusing–refocusing events within the crystal; the size of a single filament is also determined. The 15-photon absorption cross section in BaF2 is deduced to be 6.5 × 10?190 cm30 W?15 s?1. 相似文献
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Angela Dibenedetto Antonella AngeliniMichele Aresta Jayashree EthirajCarlo Fragale Francesco Nocito 《Tetrahedron》2011,67(6):1308-1313
Glycerol carbonate, synthesised via a non-phosgene route using glycerol and CO2 or urea in presence of a heterogeneous catalyst, was efficiently converted into a series of derivatives through the functionalization of the -OH moiety, using high yield, high selectivity synthetic routes not affecting the carbonate functionality. So, for example, glycerol carbonate was converted into epichlorohydrin, a product that has a large industrial application, under very mild conditions, using a two-step reaction with a 98% yield and 100% selectivity. The high yield and mild reaction conditions (very often close to the ambient conditions) make the environmentally friendly synthetic approach described in this work of potential applicative interest. All compounds prepared were fully characterized. 相似文献
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Jayashree S Lalitha R Vadivukkarasi P Kato Y Seshadri S 《Applied biochemistry and biotechnology》2011,164(5):666-680
Pink pigmented facultative methylotrophs (PPFM) isolated from water samples of Cooum and Adyar rivers in Chennai and soil
samples of forests located in various districts of Tamil Nadu, India were screened for cellulase production using carboxymethylcellulose
agar (CMC agar) medium. The strains showed wide variations in the production of clearing zones around the colonies on CMC
agar medium flooded with Congo red. CMCase and filter paper assays were used to quantitatively measure the cellulase activity
of 13 PPFM strains. Among the strains, Methylobacterium gregans, MNW 60, MHW 109, MSF 34, and MSF 40 showed cellulolytic activity ranging from 0.73 to 1.16 U mL−1 with wide temperature (35–65°C) and pH (5 to 8) tolerance. SDS-PAGE analysis of the crude enzyme of PPFM strain MNW 60 exhibited
several protein bands, and zymogram analysis revealed two dimeric cellulase bands with molecular mass of ~92 and 42 kDa. Scanning
electron microscopic studies revealed significant morphological differences between the cells grown in normal and CMC amended
medium. The strain MNW 60 was identified as Methylobacterium sp. based on biochemical, physiological, and morphological analyses, and the methylotrophic nature was authenticated by the
presence of mxaF gene, encoding methanol dehydrogenase as a key indicator enzyme of methylotrophs, with 99% similarity to Methylobacterium lusitanum. With the 16S ribosomal RNA sequence showing 97% similarity to M. lusitanum strain MP2, this can be proposed as a novel taxon of the genus Methylobacterium. The study forms the first detailed report on the extracellular cellulase production by pink pigmented Methylobacterium sp., and it is expected that this might be the basis for further studies on cellulase production by PPFMs to explore the
molecular mechanism, strain improvement, and large-scale cellulase production for its application. 相似文献
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H. J. Pant Sunil Goswami Jayashree Biswal J. S. Samantray V. K. Sharma 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(2):1039-1042
Measurement of discharge rates of fluids and solids is an essential requirement in industrial and environmental systems. Radiotracer techniques are widely used for measurement of fluids/solids in situations where conventional techniques cannot be applied. The present paper describes application of radiotracer dilution technique to measure the discharge rate of water in a canal with an objective to validate efficiency of the Concrete Volute Pump used for pumping water in the canal. 131I radioisotope having activity of 55.5 GBq was used as radiotracer. The discharge rate of water was measured to be 20.6 m3/s. 相似文献
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Toba S Srinivasan J Maynard AJ Sutter J 《Journal of chemical information and modeling》2006,46(2):728-735
This study provides results from two case studies involving the application of the HypoGenRefine algorithm within Catalyst for the automated generation of excluded volume from ligand information alone. A limitation of pharmacophore feature hypothesis alone is that activity prediction is based purely on the presence and arrangement of pharmacophoric features; steric effects remained unaccounted. Recently reported studies have illustrated the usefulness of combining excluded volumes to the pharmacophore models. In general, these excluded volumes attempt to penalize molecules occupying steric regions that are not occupied by active molecules. The HypoGenRefine algorithm in Catalyst accounts for steric effects on activity, based on the targeted addition of excluded volume features to the pharmacophores. The automated inclusion of excluded volumes to pharmacophore models has been applied to two systems: CDK2 and human DHFR. These studies are used as examples to illustrate how ligands could bind in the protein active site with respect to allowed and disallowed binding regions. Additionally, automated refinement of the pharmacophore with these excluded volume features provides a more selective model to reduce false positives and a better enrichment rate in virtual screening. 相似文献