9,984 research outputs found
Manejo de plantas daninhas na produção de arroz orgânico.
bitstream/item/78976/1/documento-304.pd
Diferenças entre espécies de Ervilhaca (Vicia sativa e Vicia villosa) quanto à sensibilidade aos herbicidas utilizados para seu controle em trigo.
bitstream/item/36298/1/comunicado-244.pd
Tolerância de Capim-arroz (Echinochloa crus-galli spp.) ao Herbicida Imazetapir + Imazapic em arrozais da região Sudeste do RS.
bitstream/item/55943/1/comunicado-253.pd
Controle químico de um biótipo de capim-arroz com provável resistência aos herbicidas inibidores de ALS - recomendação preliminar.
bitstream/item/46796/1/Circular-96.pd
Orientações para o uso correto de herbicidas no arroz BRS Sinuelo CL.
bitstream/item/32586/1/Orientacoes.para.uso.correto.de.herbicidas.no.arroz.BRS.Sinuelo.pdfResponsáveis técnicos: Giovani Theisen, André Andres (CPACT)
Épocas de controle de angiquinho e prejuízos em arroz irrigado cv. BRS QUERÊNCIA.
bitstream/item/30503/1/boletim-93.pd
On the properties of compacton-anticompacton collisions
We study the properties of compacton-anticompacton collision processes. We
compare and con- trast results for the case of compacton-anticompacton
solutions of the K(l, p) Rosenau-Hyman (RH) equation for l = p = 2, with
compacton-anticompacton solutions of the L(l,p) Cooper-Shepard- Sodano (CSS)
equation for p = 1 and l = 3. This study is performed using a Pad\'e
discretization of the RH and CSS equations. We find a significant difference in
the behavior of compacton- anticompacton scattering. For the CSS equation, the
scattering can be interpreted as "annihila- tion" as the wake left behind
dissolves over time. In the RH equation, the numerical evidence is that
multiple shocks form after the collision which eventually lead to "blowup" of
the resulting waveform.Comment: 8 pages, 7 figure
Stability and dynamical properties of Rosenau-Hyman compactons using Pade approximants
We present a systematic approach for calculating higher-order derivatives of
smooth functions on a uniform grid using Pad\'e approximants. We illustrate our
findings by deriving higher-order approximations using traditional second-order
finite-differences formulas as our starting point. We employ these schemes to
study the stability and dynamical properties of K(2,2) Rosenau-Hyman (RH)
compactons including the collision of two compactons and resultant shock
formation. Our approach uses a differencing scheme involving only nearest and
next-to-nearest neighbors on a uniform spatial grid. The partial differential
equation for the compactons involves first, second and third partial
derivatives in the spatial coordinate and we concentrate on four different
fourth-order methods which differ in the possibility of increasing the degree
of accuracy (or not) of one of the spatial derivatives to sixth order. A method
designed to reduce roundoff errors was found to be the most accurate
approximation in stability studies of single solitary waves, even though all
derivates are accurate only to fourth order. Simulating compacton scattering
requires the addition of fourth derivatives related to artificial viscosity.
For those problems the different choices lead to different amounts of
"spurious" radiation and we compare the virtues of the different choices.Comment: 12 figure
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