Vine performance and leaf physiology of conventionally and minimally pruned Sangiovese grapevines

A three-year-study (1996-1998) was carried out on field-grown Sangiovese grapevines under the temperate, humid climate of the Po Valley (northern Italy) to assess their degree of adaptation to minimal pruning (NIT) as compared to conventional pruning (CP). Evaluation included canopy growth, yield, berry ripening and grape rot incidence. In 1996 leaf function was determined as net assimilation (A); seasonal total canopy light interception and percentage of canopy gaps were also measured. As compared to CP, over the 3-year period MP showed typical features of a more rapid canopy development and earlier growth cessation, higher shoot number with shorter shoots and smaller leaves, higher yields with smaller and looser clusters less susceptible to bunch rot. Must sugar concentration was significantly lowered. Seasonal rates of A recorded on single leaves of the two pruning treatments at different shoot positions were overall similar except for higher A in young MT leaves having a chronological age of about 8-10 d. MP also showed the tendency of retarded leaf senescence. The seasonal total light interception trends indicated a linear increase with formation of leaf area in CP, whereas total fight interception in MT augmented until about 50 % of canopy filling and then remained constant with further leaf area development. This suggests that about half the leaf area produced in the MP vines contributed mostly to mutual shading rather than enhancing light interception capability, and, hence, photosynthetic capacity. The overall data indicate that a satisfactory balance in the minimally pruned Sangiovese grapevines can only be reached with further adjustments of crop level to be performed either as partial winter and/or summer pruning. Nevertheless, in MP vines the consistent feature of looser clusters which are much less susceptible to bunch rot is crucial in an area usually characterized by abundant rainfall at pre-harvest.

Seguimiento continuado de un caso real de hundimiento de los bloques de hormigón de un dique sumergido

Para el diseño de obras marítimas construidas sobre fondos arenosos, suele hacerse una estimación del hundimiento de la misma para colocar un exceso de material que compense dicho efecto y permita mantener el francobordo de diseño. La gran repercusión económica de este fenómeno ha justificado el que se haya estudiado en ensayos de laboratorio la influencia de los procesos de socavación y/o licuefacción en el hundimiento de bloques o escolleras. Para un listado actualizado de los numerosos investigadores implicados y de sus respectivas publicaciones,puede acudirse a Sumer (2014). Sin embargo, debe destacarse que hay muy pocos datos sobre el hundimiento de bloques o escolleras en casos reales (una tabla recopilatoria puede consultarse en Muñoz-Perez et al., 2015). Más aún, que los autores conozcan, no se habían publicado hasta el momento datos continuados en el tiempo del descenso de bloques. El objetivode esta ponencia es la presentación de una metodología que permite el seguimiento continuado del hundimiento de bloques así como de los resultados obtenidos en el caso real de un dique sumergido

Emission of intermediate mass fragments from hot 116^{116}Ba∗^* formed in low-energy 58^{58}Ni+58^{58}Ni reaction

The complex fragments (or intermediate mass fragments) observed in the low-energy $^{58}$Ni+$^{58}$Ni$\to ^{116}$Ba$^*$ reaction, are studied within the dynamical cluster decay model for s-wave with the use of the temperature-dependent liquid drop, Coulomb and proximity energies. The important result is that, due to the temperature effects in liquid drop energy, the explicit preference for $\alpha$-like fragments is washed out, though the $^{12}$C (or the complementary $^{104}$Sn) decay is still predicted to be one of the most probable $\alpha$-nucleus decay for this reaction. The production rates for non-$\alpha$ like intermediate mass fragments (IMFs) are now higher and the light particle production is shown to accompany the IMFs at all incident energies, without involving any statistical evaporation process in the model. The comparisons between the experimental data and the (s-wave) calculations for IMFs production cross sections are rather satisfactory and the contributions from other $\ell$-waves need to be added for a further improvement of these comparisons and for calculations of the total kinetic energies of fragments.Comment: 22 pages, 15 figure

Extended Hauser-Feshbach Method for Statistical Binary-Decay of Light-Mass Systems

An Extended Hauser-Feshbach Method (EHFM) is developed for light heavy-ion fusion reactions in order to provide a detailed analysis of all the possible decay channels by including explicitly the fusion-fission phase-space in the description of the cascade chain. The mass-asymmetric fission component is considered as a complex-fragment binary-decay which can be treated in the same way as the light-particle evaporation from the compound nucleus in statistical-model calculations. The method of the phase-space integrations for the binary-decay is an extension of the usual Hauser-Feshbach formalism to be applied to the mass-symmetric fission part. The EHFM calculations include ground-state binding energies and discrete levels in the low excitation-energy regions which are essential for an accurate evaluation of the phase-space integrations of the complex-fragment emission (fission). In the present calculations, EHFM is applied to the first-chance binary-decay by assuming that the second-chance fission decay is negligible. In a similar manner to the description of the fusion-evaporation process, the usual cascade calculation of light-particle emission from the highly excited complex fragments is applied. This complete calculation is then defined as EHFM+CASCADE. Calculated quantities such as charge-, mass- and kinetic-energy distributions are compared with inclusive and/or exclusive data for the $^{32}$S+$^{24}$Mg and $^{35}$Cl+$^{12}$C reactions which have been selected as typical examples. Finally, the missing charge distributions extracted from exclusive measurements are also successfully compared with the EHFM+CASCADE predictions.Comment: 34 pages, 6 Figures available upon request, Phys. Rev. C (to be published

Resonant Dielectronic and Direct Excitation in Crystal Channels

We have observed dielectronic and direct excitation of H-like S15+ and Ca19+ and He-like Ti20+ ions in silicon channels caused by collision with weakly bound target electrons which behave as a free-electron gas. As in vacuo, relaxation of the doubly excited states can occur radiatively leading to ions of decreased charge, but in a crystal channel collisional effects can cause double ionization. The effects are seen in both the x-ray yields and charge-state fractions, and, in the case of Ti20+, in charge-state x-ray coincidences

EVOLUTION OF THE FUSION LIKE PROCESS AROUND THE FERMI ENERGY

The study of evaporation residue from the Ne + Ag system shows that there is qualitative change in the reaction mechanism in the Fermi energy domain. At 20 MeV/u the projectile is mostly absobered by the target, while at 30-37 MeV/u a continious range of mass transfer with a large transverse momentum is observed

Influence of Neutron Enrichment on Disintegration Modes of Compound Nuclei

Cross sections, kinetic energy and angular distributions of fragments with charge 6$\le$Z$\le$28 emitted in 78,82Kr+40C at 5.5 MeV/A reactions were measured at the GANIL facility using the INDRA apparatus. This experiment aims to investigate the influence of the neutron enrichment on the decay mechanism of excited nuclei. Data are discussed in comparison with predictions of transition state and Hauser-Feshbach models.Comment: 8 pages, 1 figure, paper presented at the First Workshop on "State of the Art in Nuclear Cluster Physics" 13-16 May, 2008, at Strasbourg, France (SOTANCP2008) and accepted for publication at International Journal of Modern Physics E (Special Issue), Proceedings of SOTANCP2008 (to be published

Theory of the two-proton radioactivity in the continuum shell model

We develop the microscopic description of the two-nucleon radioactivity in the framework of the Shell Model Embedded in the Continuum. This approach is applied for the description of spontaneous two-proton radioactivity in $^{45}$Fe, $^{48}$Ni and $^{54}$Zn.Comment: 61 pages, 5 figure

Elastic scattering and breakup of 17^F at 10 MeV/nucleon

Angular distributions of fluorine and oxygen produced from 170 MeV 17^F incident on 208^Pb were measured. The elastic scattering data are in good agreement with optical model calculations using a double-folding potential and parameters similar to those obtained from 16^O+208^Pb. A large yield of oxygen was observed near \theta_lab=36 deg. It is reproduced fairly well by a calculation of the (17^F,16^O) breakup, which is dominated by one-proton stripping reactions. The discrepancy between our previous coincidence measurement and theoretical predictions was resolved by including core absorption in the present calculation.Comment: 9 pages, 5 figure

Breakup of 17^{17}F on 208^{208}Pb near the Coulomb barrier

Angular distributions of oxygen produced in the breakup of $^{17}$F incident on a $^{208}$Pb target have been measured around the grazing angle at beam energies of 98 and 120 MeV. The data are dominated by the proton stripping mechanism and are well reproduced by dynamical calculations. The measured breakup cross section is approximately a factor of 3 less than that of fusion at 98 MeV. The influence of breakup on fusion is discussed.Comment: 7 pages, 8 figure