R-Matrices for Leibniz Algebras

Leibniz agebras are a generalization of Lie algebras, where no symmetry properties of the bracket are required. In this Letter we introduce a notion of R-matrices for this structure and the related Yang–Baxter equations, and discuss some of their basic properties.     

Adsorption of the Cu<Superscript>2+</Superscript> ions from aqueous solutions on the active carbon oxidized with hydrogen peroxide and impregnated with nitrogen-containing compounds

Adsorption of the copper ions from aqueous solutions, benzene, and water on the active carbon obtained by chemical activation from walnut shells was studied. The active carbon was additionally oxidized with hydrogen peroxide and then impregnated with nitrogen-containing compounds. As a result of impregnation with melamine, a secondary porosity is formed within the oxidized active carbon, leading to an increase in the specific surface of the sorbent. A modified carbon surface is heterogeneous, and the carbons themselves exhibit catalytic activity in the oxidation of luminol and decomposition of hydrogen peroxide.     

Adsorption of cyclic hydrocarbons on Pt and the interaction of the adsorbed species with hydrogen

The adsorption of six-membered hydrocarbon cycles and cyclopentane and the interaction of hydrogen with the adsorbed layer on polycrystalline Pt-foil have been studied. The work function change (Δφ) was followed by a Kelvin probe and the C/Pt peak ratio was determined by Auger electron spectroscopy. Combining these two techniques made it possible to distinguish between chemisorption via σ-bonds and π-complex formation. Benzene and toluene adsorbed first as π-complex while cyclohexane showed initially a partial aromatization and a π-complex-like bonding to the surface. Excess hydrocarbon or addition of hydrogen transformed the π-complex into σ-bonded species. Cyclopentane adsorbed via σ-bonds and showed no significant hydrogen effect.     

Structural characterization of nanopatterned surfaces

In this work, chemically and topographically nanopatterned surfaces were produced by a top-down processing approach for biosensing devices. The nanopatterning was the result of the combination of plasma polymerisation (pp) of biofunctional materials and colloidal lithography techniques. The morphological and chemical properties induced by the plasma deposition-etching treatment were characterised by optical method combining ellipsometry and Fourier Transform Infrared spectroscopy studies. This method supported by atomic force microscopy measurements, allowed the full optical characterization of each step of the top-down process. The optical characterization of the end-up nanopatterned samples demonstrated that the chosen process is able to produce well-defined nanostructured surfaces with controlled chemical and morphological properties.     

Sample preparation procedure for the determination of sulphur and trace metals in oil products by the ICP with a minitorch using emulsions

A quick sample preparation method was used for the determination of sulphur and trace metals in oil and oily products by the ICP with a minitorch. Stable aqueous emulsions of oils and oil products were made by using two kinds of emulsifiers (one with low sulphur content, the other sulfonated). Aqueous standard solutions can be used for the preparation of calibration solutions. The contents of S, Al, Cr, Cu, Fe, Mg, Ni and Pb in aqueous emulsions were determined and the results were in good agreement with the composition of oil standard solutions used for control analysis procedure.     

Ab initio potential energy surface and pressure broadening coefficients for the He-CH3F complex

Symmetry-adapted perturbation theory has been applied to compute the He-CH₃F potential with the CH₃F molecule assumed rigid. The potential has a global minimum of −48.9 cm⁻¹ at the center of mass separation of 7.2 bohr with the helium atom lying along the C-F bond on the hydrogen’s side. The computed points were fitted to an analytic energy surface with a correct asymptotic behaviour. This potential has been used to compute the pressure broadening (PB) coefficients for the (j, k) = (0, 0) → (1, 0) and (1, 0) → (2, 0) rotational transitions of CH₃F perturbed by helium for a wide range of temperatures. Close-coupling results are compared with the experimental data of Willey et al. [J. Chem. Phys. 97 (1992) 4723], Beaky et al. [J. Mol. Struct. 352/353 (1995) 245] and infinite order sudden results are compared with those of Grigoriev et al. [J. Mol. Struct. 186 (1997) 48] for the ν₆ band of CH₃F perturbed by helium at room temperature. To our knowledge, present work is the first attempt of making fully ab initio calculations of collisional cross-sections and pressure broadening coefficients for this simple symmetric top system at low and room temperature.     

The Random Average Process and Random Walk in a Space-Time Random Environment in One Dimension

We study space-time fluctuations around a characteristic line for a one-dimensional interacting system known as the random average process. The state of this system is a real-valued function on the integers. New values of the function are created by averaging previous values with random weights. The fluctuations analyzed occur on the scale n ^1/4, where n is the ratio of macroscopic and microscopic scales in the system. The limits of the fluctuations are described by a family of Gaussian processes. In cases of known product-form invariant distributions, this limit is a two-parameter process whose time marginals are fractional Brownian motions with Hurst parameter 1/4. Along the way we study the limits of quenched mean processes for a random walk in a space-time random environment. These limits also happen at scale n ^1/4 and are described by certain Gaussian processes that we identify. In particular, when we look at a backward quenched mean process, the limit process is the solution of a stochastic heat equation.