Simultaneous photoproduction of eta and pi0 mesons on the proton

The analysis of the gammap-->etapi(0)p reaction has been performed using data from the GRAAL experiment. The total and differential cross sections and the beam asymmetry have been obtained from threshold up to 1.5 GeV of beam energy. The two resonances S11(1535) and Delta(1700) are expected to be excited in the intermediate states of this reaction. The results are used to test predictions based on the assumption that both resonances are dynamically generated from the meson-baryon interaction provided by chiral Lagrangians. The term involving the Delta(1700) excitation, followed by the decay into etaDelta(1232), is found to be dominant.     

Interdonato lemon from Nizza di Sicilia (Italy): chemical composition of hexane extract of lemon peel and histochemical investigation

Considering that the determination of authenticity and of the geographical origin of food is a very challenging issue, in this study we studied by means of histological and histochemical analyses the famous Sicilian lemon known as ‘Interdonato Lemon of Messina PGI’. Since the protected geographical indication Interdonato lemon of Messina possesses high organoleptic properties, the composition of the hexane extract of lemon peel was determined by HRGC and HRGC–MS analyses and compared with that of lemon of different cultivars. The results obtained are informative of the oil’s quality and explain the variation of the lemon essential oil composition. Given the fundamental economic implications of any fraud, the aim of this study was to determine a fingerprint able to evaluate the authentication of the geographic origin in such way to prevent frauds in national and international markets.     

Preparation and properties of a new polytype of tantalum disulfide (4Hb-TaS2)

A new polymorph of the layered compound tantalum disulfide, 4Hb-TaS₂, has been prepared in single crystal form. Measurements of magnetic susceptibility, electrical resistivity, and differential heat capacity show two first order transitions at 20 and 315°K. The 315°K transition involves only a small volume and enthalpy change, as in the previously observed transitions of another polymorph, 1T-TaS₂. The resistivity measurements show metallic like conductivity, as in 2H-TaS₂, when the current is parallel to the layers, but semiconducting like conductivity, as in 1T-TaS₂, when perpendicular to the layers. The properties of 4Hb-TaS₂ are moderately well described as a ‘mix’ of those of 1T-TaS₂ and 2H-TaS₂.     

Solvation and structure of LiAlH(4) in ethereal solvents

The nature of the solute species present in ethereal solutions of LiAlH(4) is of crucial importance for understanding the mechanisms for the reduction of ketones and other functional groups by LiAlH(4). We have employed a combination of theoretical and experimental techniques to investigate the structure of LiAlH(4) in ethereal solutions. Using complexation agents, we measured the IR spectra of LiAlH(4) and AlH(4)(-) in tetrahydrofuran (THF). Hybrid quantum-classical (QM-MM) simulations have also been carried out to compute the IR spectra of associated and dissociated LiAlH(4) species and the free-energy profile for the dissociation process in solution. Our experimental estimate of the dissociation constant in THF is 0.021 +/- 0.002, while the predicted computational value corresponding to a model dimethyl ether solvent is 0.001. The free-energy profile shows only one minimum corresponding to a contact ion pair at a Li-Al separation distance of 3.0 A. These results are consistent with the fact that LiAlH(4) is essentially associated in ethereal solutions forming contact ion pairs.     

The metabolic profile of lemon juice by proton HR-MAS NMR: the case of the PGI Interdonato Lemon of Messina

We have studied by means of High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HR-MAS NMR) the metabolic profile of the famous Sicilian lemon known as 'Interdonato Lemon of Messina PGI’. The PGI Interdonato Lemon of Messina possesses high organoleptic and healthy properties and is recognised as one of the most nutrient fruits. In particular, some of its constituents are actively studied for their chemo-preventive and therapeutic properties. In this paper, we have determined by means of HR-MAS NMR spectroscopy the molar concentration of the main metabolites constituent the juice of PGI Interdonato Lemon of Messina in comparison with that of the not-PGI Interdonato Lemon of Turkey. Our aim is to develop an analytical technique, in order to determine a metabolic fingerprint able to reveal commercial frauds in national and international markets.     

Magnetic ordering of a d1 compound: VF4

Magnetic susceptibility and nuclear magnetic resonance above and below the ordering temperature show that VF₄ is an $\text{S =}\text{1}\text{2}$, 3d¹ canted antiferromagnet with a transition temperature near 28°K and a canting angle of ～ .02 rad. The compound is not an example of a proposed nonmagnetic singlet ground state of resonating covalent bonds.     

Polarization observable measurements for γp → K+Λ and γp → K+Σfor energies up to 1.5 GeV

Beam asymmetries and hyperon recoil polarizations for the reactions γp → K ⁺Λ and γp → K ⁺Σ⁰ have been measured from the threshold production to 1500MeV with the GRAAL facility located at the ESRF in Grenoble. These results complement the database for the beam asymmetry, covering for the first time the production threshold region. Recent theoretical analyses are presented for which the beam asymmetry data bring interesting new information and allow to better determine some resonance parameters. Most importantly, these results strengthen the need of a new D₁₃ state around 1900MeV.