Ground state wave functions in the hyperspherical formalism for nuclei with A>4

The general formulation of a technically advantageous method to find the ground state solution of the Schrödinger equation in configuration space for systems with a number of particles A greater than 4 is presented. The wave function is expanded in pair-correlated hyperspherical harmonics beyond the lowest order approximation and then calculated in the Faddeev approach. A recent efficient recursive method to construct antisymmetric A-particle hyperspherical harmonics is used. The accuracy is tested for the bound state energies of nuclei with A = 6–12. The high quality of the obtained results becomes evident from a comparison with other approaches.     

Adsorption of water on reconstructed rutile TiO2(011)-(2 x 1): Ti=O double bonds and surface reactivity

Recent combined experimental and theoretical studies (Beck et al., Phys. Rev. Lett. 2004, 93, 036104) have provided evidence for Ti=O double-bonded titanyl groups on the reconstructed rutile TiO(2)(011)-(2 x 1) surface. The adsorption of water on the same surface is now investigated to further probe the properties of these groups, as well as to confirm their existence. Ultraviolet photoemission experiments show that water is adsorbed in molecular form at a sample temperature of 110 K. At the same time, the presence of a 3sigma state in the photoemission spectra and work function measurements indicate a significant amount of hydroxyls within the first monolayer of water. At room temperature, scanning tunneling microscopy (STM) suggests that dissociated water is present, and about 30% of the surface active sites are hydroxylated. These findings are well explained by total energy density functional theory calculations and Car-Parrinello molecular dynamics simulations for water adsorption on the titanyl model of TiO(2)(011)-(2 x 1). The theoretical results show that a mixed molecular/dissociative layer is the most stable configuration in the monolayer regime at low temperatures, while complete dissociation takes place at 250 K. The arrangement of the protonated mono-coordinated oxygens in the mixed molecular/dissociated layer is consistent with the observed short-range order of the hydroxyls in the STM images.     

Transverse (e,e′) Response Functions for 4He

This poster presentation is intended to show preliminary results from calculations of the inclusive (e,e′) transverse response functions of ⁴He. Up to now we have only included the E1 and M1 multipoles and therefore no comparison with experiment is shown. That will be done once all relevant multipoles have been calculated. Details of the calculation are summarized in the text below.     

Multiscale entanglement in ring polymers under spherical confinement

The interplay of geometrical and topological entanglement in semiflexible knotted polymer rings confined inside a spherical cavity is investigated by using advanced numerical methods. By using stringent and robust algorithms for locating knots, we characterize how the knot length l(k) depends on the ring contour length L(c) and the radius of the confining sphere R(c). In the no- and strong-confinement cases, we observe weak knot localization and complete knot delocalization, respectively. We show that the complex interplay of l(k), L(c), and R(c) that seamlessly bridges these two limits can be encompassed by a simple scaling argument based on deflection theory. The same argument is used to rationalize the multiscale character of the entanglement that emerges with increasing confinement.     

Higher-q Quasi-elastic 3He Transverse (e,e��) Response in a Two-Fragment Model

Recently (Efros et?al. in Phys Rev C81:034001, 2010) we have computed the ³He transverse response in the quasielastic region for momentum transfers up to 700?MeV/c using the AV18 potential with the UrbanaIX three body potential. These calculations were carried out in the active nucleon Breit (ANB) frame. Owing to the use of the ANB frame the disagreement of the conventional non-relativistic calculations with experiment has been removed for q values up to 500?MeV/c. However, for higher q values some disagreement still persists. In order to further study the issue we present here results for R _T (q, ??) computed in the Breit and Lab frames with the use of the two-fragment model.     

Multivariate optimisation and validation of a capillary electrophoresis method for the analysis of resveratrol in a nutraceutical

A rapid and simple method based on capillary electrophoresis was developed for the quality control of nutraceuticals containing resveratrol. Setting the UV detector at 280nm, the optimisation involved the separation of 11 effervescent tablet components, including the active compounds vitamin C, vitamin B(2), flavanones and hydroxycinnamic acids. Flufenamic acid was employed as internal standard. The effects of background electrolyte concentration, acetonitrile percentage and voltage were investigated by means of response surface methodology, considering as responses the critical resolution values and analysis time. The optimum conditions were found by Derringer desirability function. The background electrolyte consisted of 23mM borate buffer, adjusted to pH 10.0 with 1M sodium hydroxide, containing 7% (v/v) acetonitrile. Temperature and voltage were set at 25 degrees C and 26kV, respectively. Applying these conditions, the analysis time was below 7min. The performances of the method were tested in terms of selectivity, robustness, linearity and range, accuracy and precision and system suitability, following ICH guidelines.     

Identification and determination of mainstream and sidestream smoke components in different brands and types of cigarettes by means of solid-phase microextraction-gas chromatography-mass spectrometry

The qualitative and quantitative determination of components of mainstream and sidestream smoke has been performed by solid-phase microextraction-gas chromatography-mass spectrometry. Several brands and types of cigarettes sold in Italy were considered: normal, mild, light, extra light, some with filter and some without. Extraction of the analytes was performed by means of solid-phase microextraction (SPME) and the optimisation of the extraction procedure was performed by experimental design, taking into consideration type of fiber polymer, exposure temperature and time. Sixty-seven components of mainstream and sidestream smoke were identified. The quantified compounds (by means of deuterium-labelled isotopologues) were benzene, toluene, p-xylene, m-xylene, pyridine, o-xylene, limonene, naphthalene, phenol and nicotine. Finally, a comparison between the chemical profile of smoke from the different cigarettes was made.