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Radiocarbon content in biogenic samples is widely used to study the variation of atmospheric CO 2 due to anthropogenic activities. A total of 26 samples of evergreen and deciduous tree leaves, as well as seasonal small plant leaves, were analyzed for this study. Sampling was carried out at the end of the vegetation season from rural villages surrounding a cement factory in Mount Lebanon Province, Lebanon. Reference samples of identical species were collected during the same period from a clean zone. The conventional 14 C method was used for the determination of Δ 14 C values. The data showed that the 14 C concentration in the studied sites was significantly lower than the clean area, due to the release of anthropogenic CO 2 . In order to estimate the Suess effect, the fossil fuel fraction was determined based on equations of mass balance for CO 2 concentration, stable isotopic composition of carbon, and 14 C concentration. The results showed that selected locations are affected differently according to their distance from the factory and the wind direction.

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The kinetics of aquation of bromopentaamine cobalt(III) complex have been investigated spectrophotometrically in aqueous-organic solvent media using acetonitrile, urea, and dimethyl sulfoxide as co-solvents at 45 ≤ T ( • C) ≤ 65. The logarithms of rate constant of the aquation reaction vary nonlinearly with the reciprocal of the dielectric constant for all cosolvent mixtures, indicating a specific solute-solvent interaction. Also, the rate constants are correlated with the total number of moles of water and the organic solvents. However, the solvent effects on the solvation components of the enthalpy of activation, H ‡ , and the entropy of activation, S ‡ , have been studied. Analysis of the solvent effect confirmed a common I d mechanism for the aquation of the cobalt(III) complex. C

The potential energy curves of the low-lying doublet electronic states in the representation 2s+1 ⌳ (+/−) of the SrF molecule have been investigated by using the complete active space self-consistent field with multireference configuration interaction and multireference Rayleigh-Schrödinger perturbation theory methods. The harmonic frequency, e ; the internuclear distance, R e ; the dipole moment; and the electronic energy with respect to the ground state, T e , have been calculated for the considered electronic states. The eigenvalues, E v ; the rotational constants, B v ; and the abscissas of the turning points, R min and R max , have been investigated using the canonical functions approach. The comparison between the values of the present work and those available in the literature for several electronic states shows very good agreement. Nine new electronic states have been investigated here for the first time. PACS Nos.: 31.15.Ar, 31.25.Nj, 31.50.Df, 33.20.Vq. Résumé :Les courbes d'énergie potentielle des états électroniques de basse énergie dans la représentation 2s+1 ⌳ (+/-) de la molécule de SrF sont étudiées ici à l'aide de la méthode du champ auto-cohérent de l'espace actif complet, additionnée de l'interaction de configurations multi référence et de la théorie des perturbations de Rayleigh-Schrödinger multi référence. Nous calculons pour les états électroniques visés, la fréquence harmonique, e , la distance internucléaire, R e , le moment dipolaire et l'énergie électronique, T e , mesurée par rapport au fondamental. Dans l'approche des fonctions canoniques, nous étudions les valeurs propres, E v , les constantes rotationnelles, B v , et les abscisses des points de retour, R min et R max . Nous observons un très bon accord entre nos valeurs et celles déjà publiées dans la littérature. Neuf nouveaux états électroniques sont ici étudiés pour la première fois. [Traduit par la Rédaction]