Micrometre double-quantum ionization of Rydberg hydrogen using linearly and circularly polarized light

The European Physical Journal D - We investigate the two-color two-photon K-shell ionization of neutral atoms based on the relativistic second-order perturbation theory and independent particle...     

Electrochemical synthesis and characterization of conducting polymers in supercritical carbon dioxide

This contribution reports the first synthesis of conducting polymers (CPs), specifically, polyaniline (PAn) and polypyrrole (PPy), in supercritical carbon dioxide (scCO2). CPs synthesized electrochemically in scCO2 were characterized with cyclic voltammetry (CV), four-point probe conductivity, scanning electron microscopy (SEM), and UV-vis spectroscopy. Preliminary data indicate that CPs synthesized by this method exhibit novel morphology and high conductivity comparable to that synthesized by traditional methods.     

Base Catalysed Condensation of Acetone with Uracil Derivatives: One Step Synthesis of Pyranopyrimidines

Condensation of uracil derivatives (1,3,4) with acetone in the presence of triethylamine gave pyranopyrimidines (2,5,6).     

Activities of Hydrolases and Oxidases as Influenced by the Application of Monocrotophos in Sandy Loam Soil of Rajasthan

Continuous and repeated use of pesticides affects soil microbial flora and fauna and hence indirectly affects the activity of diverse microbial enzymes present within it. The present study investigates the interaction effect of different concentrations of monocrotophos on diverse hydrolases and oxidases, viz., protease, alkaline phosphatase, acid phosphatase, cellulase, amylase, invertase, arginine deaminase, and dehydrogenase, present in sandy loam soil of Rajasthan under in vitro conditions for 30 days. Soil sample was inoculated with three different concentrations of monocrotophos, viz., 50, 100, and 150 μg kg^-1, and incubated in dark at room temperature. At regular interval of 5 days, sample was withdrawn and enzyme activity was calculated and compared with that of control. Application of various concentrations of monocrotophos enhanced the activity of diverse enzymes present in soil. Therefore, the study revealed synergistic or additive effect of monocrotophos on all the tested microbial enzyme entities. Increasing concentration of the pesticide, however, poses an antagonistic interaction on the increment of different enzymes activities. Therefore, it can be concluded from the study that monocrotophos impose a positive effect at low concentration of pesticide, whereas high concentration poses negative effect on the activity of different enzymes present in soil.     

Time resolved spectroscopy in laser grade organic dyes

Time resolved spectroscopy is discussed along with the theoretical and experimental methods used to measure the fluorescence lifetimes in various laser grade organic dyes. The role of solvents and their viscosities in the fluorescence life time is also discussed. Different photophysical parameters have been obtained in rigid and non-rigid dye molecules.     

Applications of Fruit Polyphenols and Their Functionalized Nanoparticles Against Foodborne Bacteria: A Mini Review

The ingestion of contaminated water and food is known to cause food illness. Moreover, on assessing the patients suffering from foodborne disease has revealed the role of microbes in such diseases. Concerning which different methods have been developed for protecting food from microbes, the treatment of food with chemicals has been reported to exhibit an unwanted organoleptic effect while also affecting the nutritional value of food. Owing to these challenges, the demand for natural food preservatives has substantially increased. Therefore, the interest of researchers and food industries has shifted towards fruit polyphenols as potent inhibitors of foodborne bacteria. Recently, numerous fruit polyphenols have been acclaimed for their ability to avert toxin production and biofilm formation. Furthermore, various studies have recommended using fruit polyphenols solely or in combination with chemical disinfectants and food preservatives. Currently, different nanoparticles have been synthesized using fruit polyphenols to curb the growth of pathogenic microbes. Hence, this review intends to summarize the current knowledge about fruit polyphenols as antibacterial agents against foodborne pathogens. Additionally, the application of different fruit extracts in synthesizing functionalized nanoparticles has also been discussed.     

New catanionic surfactants, phase stability and synthesis of ultrafine CdS nanoparticles

A systematic study on the water-intake capacity of the microemulsion formed using a catanionic surfactant (synthesized by taking equimolar mixture of acid and amine) with varying hydrocarbon chain length of the acid has been carried out. A decrease in the water-intake capacity with increase in the chain length was observed. Shorter chain length of co-surfactant (1-butanol compared to 1-octanol) led to higher water-intake capacity of microemulsions which may also be attributed to the high hydrophilic-lipophilic balance (HLB) of 1-butanol. Three new microemulsions based on catanionic surfactants have been used to synthesize quantum dots of CdS. The size of CdS quantum dots decreased with increase in chain length of the acid component of the catanionic surfactant.     

Densities, speeds of sound and viscosities of binary liquid mixtures of octan-2-ol with benzene and halobenzenes at 298.15 and 303.15 K

Densities ρ, speeds of sound u, viscosities η and refractive indices n_D of binary mixtures of octan-2-ol with benzene, chlorobenzene and bromobenzene have been measured over the entire range of composition at 298.15 and 303.15 K and atmospheric pressure. From the experimental data, excess molar volumes V^E, isentropic compressibilities κ_S, excess isentropic compressibilities κ_S^E, and deviations of speeds of sound u^D, have been calculated at 298.15 and 303.15 K. These excess functions have been fitted to the Redlich-Kister polynomial equation. The viscosity data have been correlated using Kendall-Monroe, Grunberg-Nissan, Tamura-Kurata, Hind-Mclaughlin Ubbelohde and Katti-Chaudhary viscosity models, and McAllister's three-body interaction model at different temperatures.     

Preparation of cholesterol oxidase nanoparticles and their application in amperometric determination of cholesterol

Highly dispersed platinum nanoparticles were deposited on gram quantities of non-functionalized multiwalled carbon nanotubes (MWCNTs) by atomic layer deposition (ALD) in a fluidized bed reactor at 300 °C. (Methylcyclopentadienyl) trimethylplatinum and oxygen were used as precursors. The results of TEM analysis showed that ~1.3 nm Pt nanoparticles were highly dispersed on non-functionalized MWCNTs. The porous structures of MWCNTs did not change with the deposition of Pt nanoparticles. For comparison, the commercial 3 wt% Pt/C catalyst was also characterized. The ALD-prepared Pt/MWCNT was used for the hydrogenation of xylose to xylitol. The ALD-prepared Pt/MWCNT showed the best catalytic performance with 100 % conversion of xylose and 99.3 % selectivity to xylitol, compared to commercially available Pt/C, Ru/C, and Raney Ni catalysts. The stability of ALD produced Pt/MWCNT catalyst was higher than that of the commercial Pt/C, due to the presence of surface defects on the MWCNTs and the strong metal–support interaction for the ALD-prepared Pt/MWCNT catalyst.     

Characterizations of Null Holomorphic Sectional Curvature of G C R-Lightlike Submanifolds of Indefinite Nearly K ¨ahler Manifolds

We obtain the expressions for sectional curvature, holomorphic sectional curvature and holomorphic bisectional curvature of a GCR-lightlike submanifold of an indefinite nearly K ¨ahler manifold and obtain characterization theorems for holo-morphic sectional and holomorphic bisectional curvature. We also establish a condi-tion for a GCR-lightlike submanifold of an indefinite complex space form to be a null holomorphically flat.