Disentangling the reaction mechanisms of weakly bound nuclei

Complete and incomplete fusion cross sections for the ⁹Be + ¹⁴⁴Sm reaction have been measured at near-barrier energies, using the delayed X-ray detection technique. At above-barrier energies these show a suppression of complete fusion for this weakly bound projectile on an intermediate mass target. The suppression factor, attributed to ⁹Be break-up, was deduced from a comparison of complete fusion yields with coupled-channels calculations, and appears consistent with measured incomplete fusion product yields. At ∼10%, it is considerably smaller than the value of ∼30% previously found for a ²⁰⁸Pb target. Simultaneous measurements of elastic and inelastic scattering permit a clearer picture of the reaction mechanisms.     

Multielemental analysis of food and agricultural matrixes by inductively coupled plasma-mass spectrometry

The suitability of quadrupole inductively coupled plasma-mass spectrometry (ICP-MS) for multielemental analysis of food following microwave closed vessel digestion of samples was evaluated in relation to analytical challenges presented by some major food and agricultural matrixes. Fifteen key analytes (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Sn, V, Zn) were determined in 9 reference materials representative of 3 major groups of staple foods (cereals, seafood, and meat). For all measurements, the method of external calibration was used and Rh was selected as internal standard. Matrix-induced interferences were evaluated for each material, and suitable methods to overcome them were applied. Spectral interferences caused by C, Cl, and Ca content of digestates were quantitated and corrected by entering a simple system of mathematical correction equations into the instrument software before each analytical run. Full mastering of interferences together with adoption of a series of measures to control the reliability of analytical measurements produced accurate results for all the analytes. A standard analytical protocol is outlined for the benefit of both research and routine high-throughput laboratories that perform ICP-MS analyses of food.     

Die quantitative Bestimmung des Methylalkohols bei Gegenwart von ?thylalkohol im Spiritus und in Lik?ren

Ohne Zusammenfassung     

Fractional square functions and potential spaces

Carlos Segovia and Richard Wheeden defined fractional square functions involving fractional derivatives. They obtained characterizations of potential spaces via square functions. Our aim in this paper is to reconsider the ideas of Segovia and Wheeden under the light of the semigroups of operators. We develop a quite general theory of fractional square functions associated to certain classes of operators. We present some examples of differential operators where our theory applies. We recover in a more compact way the results of Segovia and Wheeden and we obtain new characterizations of the potential spaces associated to the harmonic oscillator and Ornstein–Uhlenbeck operators.     

Analysis on distribution coefficients of Strontium and Cesium for safety assessment studies

The distribution coefficients of strontium and cesium in an Italian nuclear site were studied. Distribution coefficient is a fundamental parameter in safety assessment studies on radionuclide migration into the environment. A sensitivity analysis to identify the main influencing factors on the variation of distribution coefficient in subsoil was carried out. Cation exchange capacity was identified as the main influencing parameter, thus a correlation between cation exchange capacity and distribution coefficient was estimated. In this way, the determination of cation exchange capacity, that is less consuming, makes it possible to easily obtain a preliminary, but reliable distribution coefficient on extensive sites.