[en] The study of quantum manifestations of chaos in a generalized van der Waals potential can be carried out using the SO(4, 2) group theoretical approach. We discuss certain salient features of using the method. By analysing some of the recently introduced measures such as the cumulative spacing distribution, T-function and U-function, we demonstrate the efficacy of using the Brody distribution in this problem. (author)

[en] Understanding quantum manifestations of classical chaos is of intrinsic and practical interest. In the recent years several finger prints of chaos have been recognized in microscopic systems. In this connection Rydberg atoms and molecules, which are highly excited systems under various external interactions, are found to be testing grounds to understand quantum chaos. Recent developments and their implications and future outlook are discussed. (author). 50 refs., 3 figs., 1 tab

[en] Short communication

[en] The classical dynamics of a hydrogen atom in a generalized van der Waals potential is investigated. In order to carry out the analytical and numerical investigations for a range of parametric values, we removed the singularity of the problem using Levi-Civita regularization and converted the problem into that of two coupled sextic anharmonic oscillators. We identify the integrable choices of the oscillator system using the Painleve singularity analysis, and the associated second integrals of motion are derived using the extended Lie transformations. Numerical investigations are carried out for other nonintegrable regions and we observe chaos-order-chaos type of transition regions when one of the system parameters is varied

[en] A Comment on the Letter by Y. Alhassid, E. A. Hinds, and D. Meschede, Phys. Rev. Lett. 59, 1545 (1987)

[en] Castor (Ricinus communis L.) is an important oilseed crop in India. To create variability mutations were induced in two cultivars 'TMV5' (maturing in 130-140 days) and 'CO1' (perennial type). Gamma rays and diethyl sulphate and ethidium bromide were used for seed treatment. Ten doses, from 100 to 1000 Gy were employed. For chemical mutagenesis five concentrations of mutagenes from 10 to 50 mM were tried. No economic mutants could be isolated after treatment with the chemical mutagens. The following economic mutants were identified in the dose 300 Gy of gamma rays. Annual types from perennial CO 1 castor CO 1 is a perennial variety (8-10 years) with bold seeds (100 seed weight 90 g) and high oil content (57%). Twenty-one lines were isolated with annual types (160-180 days) with high yield potential as well as bold seeds and high oil content. These mutants, identified in M₃ generation were bred true in subsequent generations up to M₈ generation. Critical evaluation of the mutants in yield evaluation trials is in progress

[en] Mesoporous CuO–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard, a well known chemical warfare agent. They were prepared by precipitation pyrolysis method and characterized by means of X-ray diffraction, transmission electron microscopy, nitrogen adsorption, Fourier transform infrared spectroscopy techniques. Obtained data indicated the presence of mesopores with diameter ranging from 2 to 80 nm and the materials exhibited relatively high surface area 86 m² g⁻¹ when compared to the individual metal oxide nanoparticles. Reactive sites of mesoporous CuO–ZnO binary metal oxide nanocomposites were studied by infrared spectroscopy technique using pyridine as a probe molecule. These materials demonstrated superior decontamination properties against sulfur mustard when compared to single component metal oxides and decontaminated it to divinyl sulfide, chloroethyl vinyl sulfide, hemisulfur mustard, etc. - Graphical abstract: Mesoporous CuO–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard, a well known chemical warfare agent. These materials demonstrated superior decontamination properties against sulfur mustard and decontaminated it to divinyl sulfide, chloroethyl vinyl sulfide, hemisulfur mustard, etc. - Highlights: • Preparation of mesoporous CuO–ZnO binary metal oxide nanocomposite. • CuO–ZnO with better surface area was synthesized by precipitation pyrolysis. • Decontamination of HD using mesoporous CuO–ZnO binary metal oxide nanocomposite. • HD decontaminated by elimination and hydrolysis reactions

[en] We consider n = 20 Rydberg states of the hydrogen atom interacting with a nearby metal surface over an atom-surface distance range of 105 nm-530 nm. We show that the traditional quadratic approximation to the potential is insufficient to follow the true potential and one needs to include higher order terms to obtain accurate energies for these Rydberg states. We include terms up to eighth order in the electron-proton distance in the potential and demonstrate by means of basis set calculations that the resulting spectra differ significantly from those obtained in the quadratic approximation. We observe an energy spread of the n = 20 manifold which is roughly twice that given by the quadratic approximation. Observed level repulsions are attributed to z-parity symmetry breaking. We compare our results with those from degenerate perturbation theory. (Author)

[en] Full text: The 5U Melbourne Pelletron is a single-ended National Electrostatics Corporation machine with three beamlines: the Melbourne microprobe, the CSIRO microprobe and an RBS/ion channeling line. Typical beams are He⁺ or H⁺ ions in the energy range 500 keV – 5.0 MeV. The accelerator facility is used for ion beam analysis and ion implantation. Analyses primarily utilise particle induced x-ray emission (PIXE), microbeam mapping and microanalysis, Rutherford backscattering spectrometry and ion channeling and nuclear reaction analysis. The accelerator supports the quantum computer development program of the Centre of Excellence for Quantum Computation and Communication Technology, diamond device and materials programs, SiC device and single photon source development and microanalyses related to mining and minerals exploration, botany and biosciences. A Maia x-ray pixel detector array has recently been installed on the CSIRO microbeam line. The detector array, with its large solid angle and parallel detection capability, enormously increases the microanalytical capabilities that are available. This presentation will provide an overview of the 5U Melbourne Pelletron facility and examples of recent analyses performed using the facility will be given to highlight the capabilities of the machine, the beamlines and accompanying instrumentation. (author)

[en] Chaos based cryptosystems are an efficient method to deal with improved speed and highly secured multimedia encryption because of its elegant features, such as randomness, mixing, ergodicity, sensitivity to initial conditions and control parameters. In this paper, two chaos based cryptosystems are proposed: one is the higher-dimensional 12D chaotic map and the other is based on the Ikeda delay differential equation (DDE) suitable for designing a real-time secure symmetric video encryption scheme. These encryption schemes employ a substitution box (S-box) to diffuse the relationship between pixels of plain video and cipher video along with the diffusion of current input pixel with the previous cipher pixel, called cipher block chaining (CBC). The proposed method enhances the robustness against statistical, differential and chosen/known plain text attacks. Detailed analysis is carried out in this paper to demonstrate the security and uniqueness of the proposed scheme.