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21.
H. Sukumar J. A. Stone T. Nishiyama C. Yuan G. A. Eiceman 《International Journal for Ion Mobility Spectrometry》2011,14(2-3):51-59
A paper spray ion source was combined with a drift tube operating at ambient pressure for mobility measurements of ions derived from pharmaceutical solutions. Paper spray ionization with solvent alone resulted in a mixture of ions convolved to a single peak with a reduced mobility of 2.19 cm2/Vs in the mobility spectrum. These were mass-identified principally as m/z 157, (MeOH)2(HCOOH)2H+ and m/z 129, (MeOH)4(H2O)H+ while pharmaceuticals with nitrogen bases formed MH+ product ions. The duration of response was governed by the volume of liquid added to the paper source and was limited by evaporation of solvent in gas at 58 °C venting the drift tube. Quantitative variation was attributed in part to morphologic changes in the tip of the paper spray source. This was associated with mass flow in the electrical discharge and not due alone to cycles of wetting and drying of the paper. Mobility spectra of chlorpromazine in urine, exhibited a single product ion peak and linear response was 30 to 500 ng with an estimated limit of detection of 1.5 ng. Ion flux could be prolonged by continuous addition of liquid and findings portend a combination of paper spray ionization IMS with paper chromatography. 相似文献
22.
Quadrupole coupling constants of Co59 has been measured in several octahedral cobaltic complexes. The compounds are diamagnetic and polycrystalline in nature. The magnitudes of the coupling constants were evaluated assumingη as zero. The temperature variation of the coupling constants are correlated with the nature of Co-ligand bond and molecular motions in the solid. 相似文献
23.
J.R. Falck Sukumar Manna Jacques Viala Arup K. Siddhanta Christine A. Moustakis Jorge Capdevila 《Tetrahedron letters》1985,26(19):2287-2290
The preparation and initial evaluation of a series of potent arachidonate epoxygenase inhibitors and heteroatom analogues of epoxyeicosatrienoic acid are described. 相似文献
24.
V. Saraswati M.S. Multani V.R. Palkar R. Vijayaraghavan A. Gurjar 《Journal of magnetism and magnetic materials》1984,43(3):256-260
Polycrystalline ceramic YIG has been synthesized with submicron microstructure. The log-log plot of FMR linewidth versus average grain size gives a power law dependence α-10 where α0 is the average grain size. The instability threshold hcrit for increasing magnetic field vector of the microwave parallel pump shows a linear log-log dependence with average grain size. 相似文献
25.
In this article, we construct a commutative unital Banach algebra, in which the property is true for the invertible elements, but cannot be extended to the whole algebra. 相似文献
26.
Synthetic dyes are released into the environment from textile industrial effluents. The discharge of this colored wastewater
into rivers and lakes leads to a reduction in sunlight penetration in natural water bodies, which, in turn, decreases both
photosynthetic activity and dissolved oxygen concentration and is toxic to living beings. Bacterial isolates are optimized
for growth and biomass production before using them for decolorizing dye effluent. The bacterial isolates Bacillus sp. 1 and Bacillus sp. 2 were employed at different percentages by volume with standard nutrient concentration. Of these bacterial isolates
Bacillus sp. 2 recorded maximum color reduction. The pH and electrical conductivity (EC) were reduced in the decolorized effluent,
and a reduction in biologic oxygen demand, chemical oxygen demand, total suspended solids, and total dissolved solids (TDS)
were also observed. 相似文献
27.
Dibyendu S. Bag Sukumar Maiti 《Journal of polymer science. Part A, Polymer chemistry》1998,36(10):1509-1513
Methylene blue sensitized photopolymerization of acrylamide (AM) and methyl methacrylate (MMA) using triethanolamine or the sodium salt of EDTA as a reducing agent has been investigated under the influence of a magnetic field (0–7.3 kG). There was no effect of the magnetic field (MF) on the polymerization of AM and MMA in aqueous medium. However, in the water–methanol mixture (1 : 1) the yield of polymer decreases and the molecular weight increases in both cases under MF. This has been explained on the basis of the triplet mechanism. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1509–1513, 1998 相似文献
28.
Kartini Ahmad Mat Ropi Mukhtar Jean-Frederic Faizal Weber Saraswati S. Velu Hiroshi Morita A. Hamid A. Hadi 《Tetrahedron》2009,65(7):1504-5660
The FeCl3-promoted oxidative cyclization/coupling of acetamidostilbenes possessing 3-methoxy, 4-methoxy and 3,5-methoxy substitutions (21), (22) and (23) is described. Only 3,5-substitution gave rise to novel indolostilbenes, each possessing two stereogenic axes (axially chiral but racemic dimers (39) and (40)). The 4-methoxy substituted acetamidostilbenes, by contrast, yielded the bisindoline dimer (36). 相似文献
29.
Sambhu Charan Barman Sukumar Mondal Madhumangal Pal 《Journal of Applied Mathematics and Computing》2009,31(1-2):369-384
In this paper, we present an efficient algorithm to find next-to-shortest path between any pair of vertices u,v on permutation graphs with n vertices which runs in O(n 2) time. 相似文献
30.
The formation and dissociation of methane gas hydrate at an interface between synthetic seawater (SSW) and methane gas have been experimentally investigated in the present work. The amount of gas consumed during hydrate formation has been calculated using the real gas equation. Induction time for the formation of hydrate is found to depend on the degree of subcooling. All the experiments were conducted in quiescent system with initial cell pressure of 11.14 MPa. Salinity effects on the onset pressure and temperature of hydrate formation are also observed. The dissociation enthalpies of methane hydrate in synthetic seawater were determined by Clausius-Clapeyron equation based on the measured phase equilibrium data. The dissociation data have been analyzed by existing models and compared with the reported data. 相似文献