Damped and sub-damped Lyman-α absorbers in z > 4 QSOs

We present the results of a survey of damped (DLA, log N(H I) > 20.3) and sub-damped Lyman-α systems (19.5 2.55 along the lines-of-sight to 77 quasars with emission redshifts in the range 4 19.5 were detected of which 40 systems are damped Lyman-α systems for an absorption length of ΔX = 378. About half of the lines of sight of this homogeneous survey have never been investigated for DLAs. We study the evolution with redshift of the cosmological density of the neutral gas and find, consistent with previous studies at similar resolution, that Ω_(DLA,HI) decreases at z > 3.5. The overall cosmological evolution of Ω_(HI) shows a peak around this redshift. The H I column density distribution for log N(H I) ≥ 20.3 is fitted, consistent with previous surveys, with a single power-law of index α ~ −1.8 ± 0.25. This power-law overpredicts data at the high-end and a second, much steeper, power-law (or a gamma function) is needed. There is a flattening of the function at lower H I column densities with an index of α ~ −1.4 for the column density range log N(H I) = 19.5−21. The fraction of H I mass in sub-DLAs is of the order of 30%. The H I column density distribution does not evolve strongly from z ~ 2.5 to z ~ 4.5

Comparison of 120Sn(6He,6He)120Sn and 120Sn(alpha,alpha)120Sn elastic scattering and signatures of the 6He neutron halo in the optical potential

Cross sections of $^{120}$Sn($\alpha$,$\alpha$)$^{120}$Sn elastic scattering have been extracted from the $\alpha$ particle beam contamination of a recent $^{120}$Sn($^6$He,$^6$He)$^{120}$Sn experiment. Both reactions are analyzed using systematic double folding potentials in the real part and smoothly varying Woods-Saxon potentials in the imaginary part. The potential extracted from the $^{120}$Sn($^6$He,$^6$He)$^{120}$Sn data may be used as the basis for the construction of a simple global $^6$He optical potential. The comparison of the $^6$He and $\alpha$ data shows that the halo nature of the $^6$He nucleus leads to a clear signature in the reflexion coefficients $\eta_L$: the relevant angular momenta $L$ with $\eta_L \gg 0$ and $\eta_L \ll 1$ are shifted to larger $L$ with a broader distribution. This signature is not present in the $\alpha$ scattering data and can thus be used as a new criterion for the definition of a halo nucleus.Comment: 13 pages, 7 figures, accepted for publication in Phys. Rev.

Manual de reconhecimento e controle das principais pragas do antúrio no Estado do Ceará.

Introdução; fungos gnats Bradysia sp. (Diptera: Sciaridae); pulgões Myzus ascalonicus Doncaster e Aphis fabae Scopoli (Hemiptera: Aphididae); Cochonilhas (Hemiptera: Diaspididae); Tripes Scirtothrips sp. (Thysanoptera: Thripidae); lagarta Phyciodes sp. (Lepidoptera: Nymphalidae); ácaros Tetranychus sp. (Acari: Tetranychidae); literatura recomendada.bitstream/CNPAT-2010/10887/1/Dc-114.pd

Efeito de indutores de resistência contra brusone em arroz

Objetivou-se comparar o efeito do ácido-acetilsalicílico e do acibenzolar-s-metílico (Bion®) em diferentes concentrações como indutores de resistência contra o patógeno Pyricularia oryzae, aplicados sete dias antes da inoculação.Pôster - pós-graduação

Coleta de germoplasma de bacuri (Platonia insignis Mart.) na Amazônia I. Microrregião campos do Marajó (Soure/Salvaterra).

bitstream/item/42253/1/Boletim-Pesquisa-132-CPATU.pd

Residue and residue flour from Chardonnay wine processing.

The aim of this study was to evaluate the viability of the production of the flour from the residue of production of Chardonnay white wines and characterize the change of the quality attributes during the transformation of the residue in residue flour