Plasma activated water: the next generation eco-friendly stimulant for enhancing plant seed germination,vigor and increased enzyme activity,a study on black gram (Vigna mungo L.)

Plasma Chemistry and Plasma Processing - Chemical fertilization in agriculture is threatening to the ecosystem. Therefore, the use of eco-friendly stimulant for crop revolution is highly desirable....     

Optimised polychromatic field-mediated suppression of H-atom tunnelling in a coupled symmetric double well: two-dimensional malonaldehyde model

The cis–cis isomerisation motion of malonaldehyde can be modelled as a symmetric double well coupled with an asymmetric double well, which includes the effect of the cis–trans out-of-plane motion on the cis–cis motion. We have presented an effective method for having control over the tunnelling dynamics of the symmetric double well which is coupled with the asymmetric double well by monitoring tunnelling splitting. When a suitable external field is allowed to interact with the system, the tunnelling splitting gets modified. As the external time perturbation is periodic in nature, the Floquet theory can be applied to calculate the quasi-energies of the perturbed system and hence the tunnelling splitting. The Floquet analysis is coupled with a stochastic optimiser in order to minimise the tunnelling splitting, which is related to slowering of the tunnelling process. The minimisation has been done by one of the stochastic optimisers, simulated annealing. Optimisation has been performed on the parameters which define the external polychromatic field, such as intensities and frequencies of the components of the polychromatic field. With the optimised sets of parameters, we have followed the dynamics of the system and have found suppression of tunnelling which is manifested by a much higher tunnelling time.     

Interaction phenomena of ion‐acoustic quasi‐solitons and classical‐solitons in three component plasma

The space–time evolution of the cnoidal‐soliton solution, characteristics of the quasi‐soliton solution of Korteweg‐de‐Vries (KdV) equation, and the interaction phenomena of ion‐acoustic waves (IAWs) are investigated in a plasma system consisting of positive and negative ions with superthermal electrons. To do this, and (Ar⁺, F^?) plasmas are considered and two‐sided KdV equations (KdVEs) are derived applying the extended Poincaré‐Lighthill‐Kuo (ePLK) method. The effects on wave structures, potential profiles, and propagation characteristics with plasma parameters of the cnoidal‐wave, quasi‐soliton solution, and head‐on collision phenomena of IAWs are presented graphically. It was found that the superthermality parameter and the mass ratio of ions play a significant role in the head‐on collision between soliton and standing cnoidal wave and reveal that the collision is elastic and both waves change their phase shifts due to collision. Moreover, the superthermality parameters are also responsible for the production of compressive and rarefactive phase shifts in overtaking collision processes between right travelling classical soliton (CS) and cnoidal wave (CW) and reduced the amplitudes of IAWs. It was also found that a new wave is created with a high amplitude in the interacting region during collision depending on the plasma parameters.     

Electron impact ionization of helium isoelectronic systems

The electron impact single ionization cross sections, on the helium isoelectronic He, Li¹⁺, B³⁺, C⁴⁺, N⁵⁺, O⁶⁺, Ne⁸⁺, Na⁹⁺, Ar⁺¹⁶, Fe²⁴⁺, Mo⁴¹⁺, Ag⁴⁵⁺, and U⁹⁰⁺ targets, are calculated modifying the simplified Bell (SBELL) model [Eur. Phys. J. D 46, 281 (2008)]. The results of the present analysis are compared with the available experimental and theoretical data. The modified SBELL (MSBELL) model, incorporating the ionic correction factor in it, produces excellent agreement with the experimental data and theoretical calculations for all the two-electron systems, neutral or ions. This model may be a prudent choice in plasma modeling due to its simple inherent structure.     

Superluminal to subluminal transition in the pulse propagation in a resonantly absorbing medium

We have examined the propagation of femtosecond laser pulses in an absorbing dye solution through a short to a long range of propagation distance. The transmitted pulses show strong spectral shift and a superluminal to subluminal transition in the propagation velocity keeping its initial shape almost intact. It is verified that the peak velocity is well described by a modified group velocity v(S) defined within the framework of the saddle-point method as well as by a recent prediction of the net group delay of surviving frequency.     

On fringe multiplication by superimposition of negatives

The mechanism of superimposition of negatives has been explained fully and it has been shown that though the technique gives the desired results, the governing equations derived by Dally and Ahimaz for the fringemultiplication technique contain inaccuracies.     

Synthèse de l'oxo-7 7H cyclohepta[b] pyridine et de quelques dérivés

This communication describes the synthesis of 7-one (7H) cyclohepta[b]pyridine and some derivatives (6,8-dimethyl; 8-methyl; 8-ethyl….). These compounds have been obtained by condensation of ketones with 2,3-diformylpyridine.     

Functor category dualities for varieties of Heyting algebras

Let be a finitely generated variety of Heyting algebras and let be the class of subdirectly irreducible algebras in . We prove that is dually equivalent to a category of functors from into the category of Boolean spaces. The main tool is the theory of multisorted natural dualities.     

Generalized Kolbenstvedt model for electron impact ionization of K-, L- and M-shell atoms

The recently modified Kolbenstvedt (MKLV) model [Eur. Phys. J. D 37, 361 (2006)], developed for electron impact ionization (EII) of the K-shell atomic targets, has been extended to generalize its two parameters in terms of the electronic orbitals nl. The generalized MKLV (GKLV) with two sets of the species independent parameters for the same nl, one set for the ionization of inner orbits and another for the outermost orbit, is found profoundly successful in accounting for the EII cross section data of the K, L and M-shell neutral atoms with atomic numbers Z = 1-92 for the incident energies up to 1000 MeV in a consistent manner.