A new spectrophotometric method for the determination of Baygon in environment and biological samples

A sensitive, selective, cheaper and extractive spectrophotometeric method has been developed for the detection and determination of Baygon in fruits, vegetables, and grains is based on the coupling of their hydrolysation products with diazotized aniline. The dyes formed are measured at 450nm for Baygon after extraction in chloroform. Beer’s law is obeyed over concentration ranges of 0.8-5.0µg. The Molar absorptivity and Sandell’s sensitivity were found to be 9.7×105 L mol-1 cm-1 and 0.5×10-4 µg cm-2 respectively. The standard deviation and relative standard deviation were observed as ± 0.00336 and 0.0145% respectively. Various important analytical parameters were evaluated. The method was applied successfully to the determination of Baygon in water, grain, fruits, plant material and biological sample

Low cost spectro photometric determination of paraquat in environmental and biological sample

An extractive, sensitive spectrophotometer method has been developed for the detection and determination of paraquat using glucose ( as easily available reducing agent ). Paraquat is reduced with glucose in alkaline medium to give a blue colored ion with an absorbance maxima at 610 nm. Beer’s law is obeyed in the range 0.5-5.0 µg of paraquat in 10ml of the final solution (ppm). The important analytical parameters and the optimum reaction conditions were evaluated. The method was applied successfully to the determination of paraquat in water, grain, plant material and biological sample

Dissociative Autoionization in (1+2)-photon Above Threshold Excitation of H2 Molecules

We have theoretically studied the effect of dissociative autoionization on the photoelectron energy spectrum in (1+2)-photon above threshold ionization(ATI) of H2 molecules. We have considered excitation from the ground state X-singlet-Sigma-g+(v=0,j) to the doubly excited autoionizing states of singlet-Sigma-u+ and singlet-Pi-u+ symmetry, via the intermediate resonant B-singlet-Sigma-u+(v=5,j) states. We have shown that the photoelectron energy spectrum is oscillatory in nature and shows three distinct peaks above the photoelectron energy 0.7 eV. This feature has been observed in a recent experiment by Rottke et al, J. Phys. B, Vol. 30, p-4049 (1997).Comment: 11 pages and 4 figure

Some entanglement features of three-atoms Tavis-Cummings model: Cooperative case

In this paper we consider a system of identical three two-level atoms interacting at resonance with a single-mode of the quantized field in a lossless cavity. The initial cavity field is prepared in the coherent state while the atoms are taken initially to be either in the uppermost excited state "$|eee>$" or The $\textmd{GHZ}$-state or the $\textmd{W}$-state. For this system we investigate different kinds of atomic inversion and entanglement, which arise between the different parts of the system due to the interaction. Also the relationship, between entanglement and some other nonclassical effects in the statistical properties, such as collapses and revivals in the atomic inversion where superharmonic effects appear, is discussed. The $Q$-functions for different cases are discussed. Most remarkably it is found that the $\textmd{GHZ}$-state is more robust against energy losses, showing almost coherent trapping and Schr\"odinger-cat states can not be produced from such state. Also the entanglement of $\textmd{GHZ}$-state is more robust than the $\textmd{W}$-state. Another interesting feature found is that the state which has no pairwise entanglement initially will have a much improvement of such pairwise entanglement through the evolution. Sudden death and sudden revival of atoms-pairwise entanglement are produced with the $\textmd{W}$-state.Comment: 14 pages, 7 figure

Variation of rayleigh wave group velocity dispersion and seismic heterogeneity of the Indian crust and uppermost mantle

We present group velocity dispersion results from a study of regional fundamental mode Rayleigh waves propagating across the Indian region. 1-D, path-averaged dispersion measurements have been made for 1001 source-receiver paths and these combined to produce tomographic images between 15 and 45 s period. Because of the dense station coverage in peninsular India, these images have substantially higher lateral resolution for this region than is currently available from global and regional group velocity studies. Testing of the group velocity model shows that the average resolution across the region is about 7.5° for the periods used in this study. The tomographic maps demonstrate that while the Indian shield is characterized by high crustal and uppermost-mantle group velocities, comparatively lower velocities exist beneath the Himalaya due to the thickened crust and beneath the Gangetic plains caused by the mollasse sediments and recent alluvium cover in the Himalayan foredeep. Northeastern India north of the Shillong Plateau also displays higher velocities, similar to the south Indian shield, indicative of colder crust beneath the region. The northern Bay of Bengal shows extremely low velocities due to the thick sediment blanket of the Bengal fan. Likewise, the Katawaz Basin in southern Pakistan shows lower velocities that resemble those seen in the Bay of Bengal. The geometry of the velocity contours south of the Katawaz Basin closely matches the prograding Indus fan in the Arabian Sea. Finally, the Tibetan Plateau has lower group velocities compared to the Indian shield at all periods as a result of the thick crust beneath southern Tibet

A new sensitive spectrophotometric determination of cypermethrin insecticide in environmental and biological samples

A new and highly sensitive spectrophotometric method was developed for the determination of parts per million levels of widely used cypermethrin insecticide. The method is based on alkaline hydrolysis of cypermethrin to cyanide ion, which further reacts with potassium iodide and leuco crystal violet. The absorption maxima of the crystal violet dye formed was measured at 595 nm in acidic medium. Beer's law obeys over the concentration range of 3.0 to 17 µg in a final solution volume of 25 mL (0.12-0.68 ppm). The molar absorptivity and Sandell's sensitivity were found to be 3.3<FONT FACE=Symbol>&acute;</FONT>10(5) L mol-1 cm-1 and 0.054 µg cm-2, respectively. The standard deviation and relative standard deviation were found to be &plusmn; 0.001 and 0.22%, respectively. The method is simple, sensitive and free from interferences of other pesticides and diverse ions. Other pyrethroid insecticides do not interfere in the proposed method. The method has been satisfactorily applied to the determination of cypermethrin in environmental and biological samples

Oscillation frequency of B and B mesons in a QCD potential model with relativistic effect

Wavefunction at the origin with the incorporation of relativistic effect leads to singularity in a specific potential model. To regularise the wavefunction, we introduce a short distance scale here and use it to estimate masses and decay constants of Bd and Bs mesons within the QCD potential model.These values are then used to compute the oscillation frequency \Delta mB of Bd and Bs mesons. The values are found to be in good agreement with experiment and other theoretical values.Comment: 10 page