Exploring the Pion Phenomenology Within a Fully Covariant Constituent Quark Model

An overview of the vector and tensor Generalized Parton Distributions for a charged pion is presented. Such observables, belonging to the set of quantities fundamental for a detailed investigation of the hadronic inner dynamics, have been evaluated within a fully covariant Constituent Quark Model, based on a proper Ansatz of the pion Bethe–Salpeter Amplitude and the Mandelstam formula for matrix elements of operators acting on relativistic composite systems. Given the very encouraging results already obtained for the vector distribution of a charged pion, the model has been extended to the tensor one, and some preliminary calculations will be illustrated.     

Elliptic operators with general Wentzell boundary conditions,analytic semigroups and the angle concavity theorem

We prove a very general form of the Angle Concavity Theorem, which says that if (T (t)) defines a one parameter semigroup acting over various L^p spaces (over a fixed measure space), which is analytic in a sector of opening angle θ_p, then the maximal choice for θ_p is a concave function of 1 – 1/p. This and related results are applied to give improved estimates on the optimal L^p angle of ellipticity for a parabolic equation of the form ?u /?t = Au, where A is a uniformly elliptic second order partial differential operator with Wentzell or dynamic boundary conditions. Similar results are obtained for the higher order equation ?u /?t = (–1)^{m +l}A^mu, for all positive integers m.     

Asymmetric electron spin relaxation in ClO2 solution. Deviation of the motional correlation time from modified Debye theory

In highly viscous solutions the ESR spectra of chlorine dioxide are asymmetrically broadened. Modulation of the anisotropic hyperfine and g tensors accounts for the observed broadening but the correlation time for the motion is much smaller than expected from Debye theory. The calculated hydrodynamic radius is compared with that derived from spin rotational relaxation.     

Synthesis and characterization of functionalized silica as fillers of polymeric systems

This study investigates the functionalization of sol-gel silica with selected organic species, and compares the materials obtained to a commercially available silica functionalized under comparable conditions. Anilines with different active groups were grafted onto the surface of the silicas, via reaction with key surface sites, to modulate the hydrophobicity of the materials. The properties of the functionalized materials, as determined by FT-IR, DTA-TGA and nitrogen adsorption (surface area, S_BET) are discussed.     

Complete 1H and 13C NMR spectral assignment of N-aralkylsulfonamides, N-sulfonyl-1,2,3,4-tetrahydroisoquinolines and N-sulfonyl-2,3,4,5-tetrahydro-1H-2-benzazepines. Conformational analysis of N-[((3',4'-dichlorophenyl)methyl)sulfonyl]-3-methyl-2,3,4,5-tetrahydro-1H-2-benzazepin

The complete and unambiguous assignment of the 1H NMR and 13C NMR spectra of 26 N-aralkylsulfonamides, N-sulfonyl-1,2,3,4-tetrahydroisoquinolines and N-sulfonylbenz[c]azepines was performed on the basis of APT, DEPT, homonuclear (gs-COSY) and 1H-detected heteronuclear one-bond (gs-HMQC) and long-range (gs-HMBC) correlation experiments. The methylated 2,3,4,5-tetrahydro-1H-2-benzazepine derivative 26 adopts a chair conformation as determined by 1H-1H coupling analysis and gamma-gauche effects. This is supported by a single-crystal X-ray structure analysis.     

Comparative analysis of pulsed electron spin resonance spectrometers at X-band and S-band

Comparative analysis of pulsed electron spin resonance spectroscopy at X-band and at S-band indicates that despite the lower sensitivity at the lower frequency, electron spin echo spectroscopy at S-band provides valuable information on the electron-nuclear interactions in systems where the electron spin echo modulation is too small to study well at X-band. It is shown that independent experimental data on electron spin echo modulation and decay at both X-band and S-band put additional constraints on the structural parameters obtained by comparison of experimental and simulated nuclear modulation patterns, and can also help to elucidate the electron spin relaxation mechanism.