Propagation of mesons in asymmetric nuclear matter in a density dependent coupling model

We study the propagation of the light mesons sigma, omega, rho, and a0(980) in dense hadronic matter in an extended derivative scalar coupling model. Within the scheme proposed it is possible to unambiguously define effective density-dependent couplings at the Lagrangian level. We first apply the model to study asymmetric nuclear matter with fixed isospin asymmetry, and then we pay particular attention to hypermatter in beta-equilibrium. The equation of state and the potential contribution to the symmetry coefficient arising from the mean field approximation are investigated.Comment: 17 pages, 15 PostScript figure

A phytosociological survey of the boreal forest (Vaccinio-Piceetea) in North America

A survey of syntaxa of vegetation of North American boreal forests (class Vaccinio-Piceetea) is presented. This phytosociological survey, carried out combining the Braun-Blanquet method with numerical syntaxonomical analyses (cluster and correspondence analysis), describes the associations of the North American boreal forests, which have several species, varieties or vicariant species in common with their Eurasian counterparts, and can be placed in the class Vaccinio-Piceetea. By means of tabular and multivariate analyses, 2084 North American relevés were compared with 3273 relevés from European, Japanese and Korean boreal forest, to describe and typify 4 orders, 10 alliances and 37 associations. Diagnostic tables, ordination, clustering, and climatic, edaphic and biogeographical data were used to show floristic affinities among these syntaxa and interpret their distribution areas. Syntaxa were briefly characterized by their floristic composition, physiognomy, succession, zonation, and biogeographical distribution

Granular flow through an aperture: influence of the packing fraction

For the last 50 years, the flow of a granular material through an aperture has been intensely studied in gravity-driven vertical systems (e.g. silos and hoppers). Nevertheless, in many industrial applications, grains are horizontally transported at constant velocity, lying on conveyor belts or floating on the surface of flowing liquids. Unlike fluid flows, that are controlled by the pressure, granular flow is not sensitive to the local pressure but rather to the local velocity of the grains at the outlet. We can also expect the flow rate to depend on the local density of the grains. Indeed, vertical systems are packed in dense configurations by gravity but, in contrast, in horizontal systems the density can take a large range of values, potentially very small, which may significantly alter the flow rate. In the present article, we study, for different initial packing fractions, the discharge through an orifice of monodisperse grains driven at constant velocity by a horizontal conveyor belt. We report how, during the discharge, the packing fraction is modified by the presence of the outlet and we analyze how changes in the packing fraction induce variations in the flow rate. We observe that variations of packing fraction do not affect the velocity of the grains at the outlet and, therefore, we establish that flow-rate variations are directly related to changes in the packing fraction

Rheological characterization of the thermal gelation of cowpea protein isolates: Effect of pretreatments with high hydrostatic pressure or calcium addition

Pretreatments with high hydrostatic pressure (HHP) or calcium addition were assessed for thermal gelation of two cowpea protein isolates (protein extraction at pHs 8.0, standard (A8) or 10.0, pH-shifting-modified (A10). Maximum temperature of thermal processing and protein concentration (PC) on rheological behavior during and after gelling process were evaluated for pretreated isolates. The main effects of pretreatments occurred during heating since the proportion of heat-induced interactions that stabilized the matrixes increased. Those effects were due to partial denaturation (induced by HHP) and increase in Td (induced by CaCl2). HHP allowed gelation at temperatures (50–70 °C) lower than denaturation temperature and the obtaining of stronger gels at the highest PC (10.5 or 12.0 g/100 g). Calcium addition allowed gelation at low PC, but higher temperatures (80–95 °C) were required. Despite both pretreatments, A10 retained its ability to gel at lower PC than A8. Pressurized A10-gels were stronger than A8-gels. Calcium-added A10-gels were stronger than A8-gels at low PC (up to 7.5 g/100 g) or at high temperatures (90–95 °C), but no differences were found at high PC or at low temperatures. Thus, calcium-addition canceled those differences between A8 and A10 at high PC and at low temperatures.Fil: Peyrano, Felicitas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentina. École Nationale Vétérinaire, Agroalimentaire et de l'Alimentation; Francia. Centre National de la Recherche Scientifique; FranciaFil: de Llamballerie, Marie. Centre National de la Recherche Scientifique; Francia. École Nationale Vétérinaire, Agroalimentaire et de l'Alimentation; Francia. Centre National de la Recherche Scientifique; FranciaFil: Avanza, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Speroni Aguirre, Francisco José. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

Luz Pepe de Suárez (et alii). Deixis Social y Performance en la Literatura Griega Clásica. La Plata, Centro de Estudios Helénicos, IdIHCS, Facultad de Humanidades y Ciencias de la Educación, Universidad de La Plata, 2011, 120 pp. (Edición a cargo de Graciela Zecchin de Fasano).

Fil: Aguirre de Zárate, Susana. Universidad Nacional de Cuy