14,509 research outputs found
CaracterÃsticas do herbicida Foramsulfuron lodosulfuron-Methyl-Sodium na cultura do milho.
bitstream/item/25616/1/Circ-58.pd
Atomic and nano-scale characterization of a 50-year-old hydrated C3S paste
This paper investigates the atomic and nano-scale structures of a 50-year-old hydrated alite paste. Imaged by TEM, the outer product C-S-H fibers are composed of particles that are 1.5-2 nm thick and several tens of nanometers long. 29Si NMR shows 47.9% Q1 and 52.1% Q2, with a mean SiO4 tetrahedron chain length (MCL) of 4.18, indicating a limited degree of polymerization after 50 years' hydration. A Scanning Transmission X-ray Microscopy (STXM) study was conducted on this late-age paste and a 1.5 year old hydrated C3S solution. Near Edge X-ray Absorption Fine Structure (NEXAFS) at Ca L3,2-edge indicates that Ca2 + in C-S-H is in an irregular symmetric coordination, which agrees more with the atomic structure of tobermorite than that of jennite. At Si K-edge, multi-scattering phenomenon is sensitive to the degree of polymerization, which has the potential to unveil the structure of the SiO44 - tetrahedron chain
Teste de vigor em progênies de cupuaçu (Theobroma grandiflorum Willd. ex Spreng.) K. Schum.
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Functional integral over velocities for a spinning particle with and without anomalous magnetic moment in a constant electromagnetic field
The technique of functional integration over velocities is applied to the
calculation of the propagator of a spinning particle with and without anomalous
magnetic moment. A representation for the spin factor is obtained in this
context for the particle in a constant electromagnetic field. As a by-product,
we also obtain a Schwinger representation for the first case.Comment: latex, 19 page
Granular Pressure and the Thickness of a Layer Jamming on a Rough Incline
Dense granular media have a compaction between the random loose and random
close packings. For these dense media the concept of a granular pressure
depending on compaction is not unanimously accepted because they are often in a
"frozen" state which prevents them to explore all their possible microstates, a
necessary condition for defining a pressure and a compressibility
unambiguously. While periodic tapping or cyclic fluidization have already being
used for that exploration, we here suggest that a succession of flowing states
with velocities slowly decreasing down to zero can also be used for that
purpose. And we propose to deduce the pressure in \emph{dense and flowing}
granular media from experiments measuring the thickness of the granular layer
that remains on a rough incline just after the flow has stopped.Comment: 10 pages, 2 figure
Efeito de alguns aditivos sobre a qualidade e valor nutritivo da silagem de capim-elefante.
bitstream/item/143033/1/2052.pd
Capim-colonião e seus efeitos sobre o crescimento inicial de clones de Eucalyptus x urograndis.
Esta pesquisa teve o objetivo de avaliar o efeito da convivência de capim-colonião sobre o crescimento inicial de plantas de clones de eucalipto. Foram instalados dois ensaios com mudas de clones de eucalipto e de capim-colonião, que cresceram em parcelas delimitadas lateralmente por paredes de alvenaria preenchidas com terra. O primeiro ensaio obedeceu ao delineamento experimental inteiramente casualizado, com três repetições, e tratamentos em esquema fatorial 5 x 2 (cinco clones de eucalipto, e a ausência ou presença de duas plantas de capim-colonião plantadas a 10 cm da muda de eucalipto). O segundo ensaio foi semelhante ao primeiro, porém, com apenas três clones de eucalipto, cinco repetições, e tratamentos em esquema fatorial 3 x 2 (três clones de eucalipto e a ausência ou presença de capim-colonião). Os clones de eucalipto não afetaram de modo diferenciado o crescimento de capim-colonião, sendo que aqueles que conviveram com a planta daninha não apresentaram diferença no seu desenvolvimento, igualando-os quando sob competição. As caracterÃsticas dos clones de eucalipto mais sensÃveis à convivência com capim-colonião foram: área foliar, matéria seca de folhas e caule. O clone 3 foi o que se mostrou mais sensÃvel à convivência com capim-colonião e o clone 1 mais tolerante, porém todos os clones estudados tiveram influência negativa da convivência com capim-colonião
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