477 research outputs found

    Collisional Quenching at Ultralow Energies: Controlling Efficiency with Internal State Selection

    Full text link
    Calculations have been carried out for the vibrational quenching of excited H2_2 molecules which collide with Li+^+ ions at ultralow energies. The dynamics has been treated exactly using the well known quantum coupled-channel expansions over different initial vibrational levels. The overall interaction potential has been obtained from the calculations carried out earlier in our group using highly correlated ab initio methods. The results indicate that specific features of the scattering observables, e.g. the appearance of Ramsauer-Townsend minima in elastic channel cross sections and the marked increase of the cooling rates from specific initial states, can be linked to potential properties at vanishing energies (sign and size of scattering lengths) and to the presence of either virtual states or bound states. The suggestion is made that by selecting the initial state preparation of the molecular partners, the ionic interactions would be amenable to controlling quenching efficiency at ultralow energies

    Individualized Breakfast Programs or Glycogen Super-Compensation: Which Is the Better Performing Strategy? Insights from an Italian Soccer Referees Cohort

    Get PDF
    The role of soccer referees has grown in importance in the last decades, as has attention to their performance, which may be influenced and improved with specific and evolved training programs. Today, multiple specialists are working as a team in order to develop effective training programs. Moreover, for athletes, it is becoming more and more important to be attentive to nutrition. By considering such items, in this study, we aimed to investigate the nutritional habits of a group of referees belonging to the Italian Soccer Referees' Association (on behalf of AIA-FIGC). Our main aim was to spread a "culture of nutrition" in refereeing, starting with a survey on referees' breakfast attitudes and in order to disseminate such a "culture", we chose top-level elite referees who were younger subjects (despite the average 4 years' experience). Therefore, we enrolled 31 subjects (aged 22.74 \ub1 1.79, BMI 22.30 \ub1 1.53) and asked them about their breakfast habits. Then, for measuring their performance, we used the conventional fitness test named Yo-Yo (YYiR1), performed in three different sessions (test 1, test 2, test 3). Test 1 was carried out without any nutritional indications, test 2 was given after individualized breakfast suggestions by a designed dietician, and test 3 after an individualized glycogen super-compensation strategy. The Wilcoxon statistical analysis indicates that following an individualized breakfast strategy may enhance referees' performance (p < 0.0001), whereas no significant effects were observed with the glycogen super-compensation option. However, further studies will be necessary to better address this topic and clarify whether high-carbohydrates (high-CHO) intake may be useful in other sports

    Neutral and ionic dopants in helium clusters: interaction forces for the Li2(a3Σu+)−HeLi_2(a^3\Sigma_u^+)-He and Li2+(X2Σg+)−HeLi_2^+(X^2\Sigma_g^+)-He

    Full text link
    The potential energy surface (PES) describing the interactions between Li2(1Σu+)\mathrm{Li_{2}(^{1}\Sigma_{u}^{+})} and 4He\mathrm{^{4}He} and an extensive study of the energies and structures of a set of small clusters, Li2(He)n\mathrm{Li_{2}(He)_{n}}, have been presented by us in a previous series of publications [1-3]. In the present work we want to extend the same analysis to the case of the excited Li2(a3Σu+)\mathrm{Li_{2}}(a^{3}\Sigma_{u}^{+}) and of the ionized Li2+(X2Σg+)_{2}^{+}(X^{2}\Sigma_{g}^{+}) moiety. We thus show here calculated interaction potentials for the two title systems and the corresponding fitting of the computed points. For both surfaces the MP4 method with cc-pV5Z basis sets has been used to generate an extensive range of radial/angular coordinates of the two dimensional PES's which describe rigid rotor molecular dopants interacting with one He partner
    • …
    corecore