Nuclear track detector response to energetic heavy ions: study case

Journal of Radioanalytical and Nuclear Chemistry - Nuclear track methodology (NTM), is employed to analyze PADC detectors response to different energetic ion beams. Due to the passive device...     

Paraexponentials, Muckenhoupt weights, and resolvents of paraproducts

We analyze the stability of Muckenhoupt's and classes of weights under a nonlinear operation, the -operation. We prove that the dyadic doubling reverse Hölder classes are not preserved under the -operation, but the dyadic doubling classes are preserved for . We give an application to the structure of resolvent sets of dyadic paraproduct operators.

     

Solving confluent Vandermonde systems of Hermite type

In this paper the authors develop two algorithms to solve systems of linear equations where the coefficients form a confluent Vandermonde matrix of Hermite type, or its transpose. These algorithms reduce the given system to upper triangular form by means of elementary matrix transformations. Recursive formulas to obtain the upper triangular form in an economical way are derived. Applications and numerical results are included.Algol-60 programs are appended.     

Monte Carlo simulation of the enantioseparation process

By means of Monte Carlo simulation, a study of enantioseparation by capillary electrophoresis has been carried out. A simplified system consisting of two enantiomers S (R) and a selector chiral C, which reacts with the enantiomers to form complexes RC (SC), has been considered. The dependence of Δμ$\Delta \mu$ (enantioseparation) with the concentration of chiral selector and with temperature have been analyzed by simulation. The effect of the binding constant and the charge of the complexes are also analyzed. The results are qualitatively satisfactory, despite the simplicity of the model.     

Surface diffusion on heterogeneous correlated substrates

The behaviour of the surface diffusion coefficient on an heterogeneous correlated surface is studied in the framework of the lattice-gas model. Using the multivariate adsorptive energy distribution function the statistical properties of the heterogeneous correlated surface can be appropriately described and the effect of the heterogeneity on the collective diffusion coefficient at finite coverage can be analized through a correlation length. Monte Carlo simulation is also performed to test the analytical results.     

Frontier molecular orbital analysis for determining the equilibrium geometries of atmospheric prenucleation complexes

A systematic characterization of the frontier molecular orbitals (FMO) of gas-phase prenucleation complexes between H₂SO₄ and other molecules present in the atmosphere (NH₃, H₂O, (CH₃)OH, HF, (CH₃)₂PH, (CH₃)SH) is carried out using the ωB97X-D/6-311++(2d,2p) method at the density functional theory level of theory. The FMO theory principles are taken into account to gain insight into the nature of intermolecular interactions. The results show that the highest occupied molecular orbital/lowest unoccupied molecular orbital molecular system characterization can be adopted as a complementary tool of analysis in supporting the study of atmospheric prenucleation processes. It is shown that the stability and the spatial arrangement of molecular systems can be also thought in terms of inter- and intra-molecular energy gaps ΔE_HL that play an important role in the development of association processes.     

Selection rules for optical transition probabilities in superlattices

Based on numerical evaluations of the transition probabilities, and using true superlattice eigenfunctions derived from the theory of finite periodic systems, new superlattice selection rules are obtained. We show that the evaluation of the large number N   of the possible recombination transitions reduces by a factor of two. We also show that taking into account these selection rules, the theoretical calculations for specific blue emitting GaN?(In_xGa_1-xN?In_yGa_1-yN)ⁿ?GaN$\text{GaN}?({\text{In}}_x{\text{Ga}}_{1-x}\text{N}?{\text{In}}_y{\text{Ga}}_{1-y}\text{N}{)}^n?\text{GaN}$ superlattices agree with those reported by Nakamura et al. [1].     

Non-interacting dimer kinetics in hypercubic lattices

The exact formulation of the kinetic of dimer in hypercubic lattices is developed in the framework of the kinetic lattice gas model. The so-called local evolution rules are used to obtain the hierarchy of equation of motion for the correlation functions where processes like adsorption and desorption are included. The hierarchy of equations are truncated using a mean field (m, n) closures which allows the analytical treatment of the system. A general expression for non-interacting dimer isotherm and two particle correlation functions are obtained in hypercubic lattices.