5,122 research outputs found
Efeito do feijoeiro Olathe Pinto M1-4 geneticamente modificado sobre o desenvolvimento do caruncho Zabrotes subfasciatus.
Foi avaliado o efeito do feijoeiro (Phaseolus vulgaris) Cv. Olathe Pinto M1-4 geneticamente modificado (FGM) sobre o desenvolvimento do Zabrotes subfasciatus durante 10 gerações e comparado com outros cultivares de acordo com os tratamentos: 1) FGM; 2) Cultivar Olathe Pinto convencional (FC); 3) Cultivar Jalo Precoce (padrão de comparação, grão utilizado na criação massal desse inseto); 4) Cultivar Pérola (padrão de comparação como cultivar suscetÃvel); 5) Linhagem de feijoeiro silvestre contendo o alelo arcelina 1, proteÃna que confere resistência ao caruncho.Resumo ID: 2040-1
On the role of shield wires in mitigating lightning-induced overvoltages in overhead lines. Part II: Simulation results for practical configurations
In the companion Part I, the theory relevant to the role of shield wires in mitigating lightning-induced overvoltages in overhead lines has been analyzed and clarified. A more consistent meaning has been assigned to the concept of Shielding Factor by introducing two innovations compared to the current literature: the first one concerning the distinction between internal and external parameters, and the other one concerning the point along the line where to assess the mitigation effect. Thanks to this new approach, uncertainties seen in the literature have been sorted out, and the Shielding Factor has been shown to be a parameter which can be precisely quantified. However, our new contribution was applied to a schematic (unrealistic) configuration: a line with a shield wire grounded at only one point. This Part II is precisely devoted to confirming the results obtained in Part I, by applying the proposed approach to more realistic and practical line configurations, namely a line with multi-grounded shield wire, and a line equipped with laterals too
On the role of shield wires in mitigating lightning-induced overvoltages in overhead lines. Part I: a critical review and a new analysis
The ability of shield wires installed in overhead lines to mitigate lightning-induced overvoltages has been extensively investigated. Unfortunately, these studies came to different results, sometimes contradicting each other: some authors found that shield wires produce a significant overvoltage reduction, while others found the reduction negligible; conflicting results also pertain to the role played by the various parameters involved, such as the relative height of the shield wires compared to the phase conductors. This paper aims to clarify this topic. The paper is organized in two parts: Part I, which starts from the analysis of the theory behind the mitigation effect, is devoted to establishing a more solid base to the topic. Two fundamental improvements are proposed: the first one is the distinction between internal and external of the parameters involved: current literature makes an indiscriminate grouping of all of them; the second one is concerned with the point along the line where the mitigation effect needs to be assessed. Thanks to this new approach, we show that this effect can be precisely quantified. The analysis in this Part I is limited to the basic case of a single grounding point of the shield wire, which represents an unrealistic case. Part II is devoted to completing the study, by applying the proposed approach to more realistic and practical cases
CaracterÃsticas agronômicas, botânicas, e fenológicas de genótipos de arroz-vermelho.
O objetivo deste trabalho foi apresentar algumas informações sobre os genótipos de arroz-vermelho coletados em regiões brasileiras
Caracterização morfoagronômica e fenológica de acessos da coleção de arroz da Embrapa Arroz e Feijão.
O objetivo deste trabalho foi estudar as caracterÃsticas morfoagronômicas e fenológicas de acessos de arroz-cateto coletados em regiões de cultivo no paÃs
Variation of the speed of light with temperature of the expanding universe
From an extended relativistic dynamics for a particle moving in a cosmic
background field with temperature T, we aim to obtain the speed of light with
an explicit dependence on the background temperature of the universe. Although
finding the speed of light in the early universe much larger than its current
value, our approach does not violate the postulate of special relativity.
Moreover, it is shown that the high value of the speed of light in the early
universe was drastically decreased before the beginning of the inflationary
period. So we are led to conclude that the theory of varying speed of light
should be questioned as a possible solution of the horizon problem.Comment: 3 pages and 1 figure; Phys. Rev. D86, 027703 (2012
Avaliação dos artrópodes em feijoeiro (Phaseolus vulgaris) convencional e geneticamente modificado em Sete Lagoas, MG.
O objetivo deste trabalho foi avaliar o efeito do feijoeiro geneticamente modificado sobre a população de artrópodes e outros invertebrados da superfÃcie do solo.CONAFE
Descritores botânicos, agronômicos e fenológicos do arroz (Oryza sativa L.).
O presente trabalho teve por objetivo apresentar os descritores morfológicos, agronômicos e fenológicos, bem como suas escalas e critérios utilizados na descrição das linhagens e genótipos de arroz, na Embrapa Arroz e Feijão, e que além de necessários para registro e proteção, são importantes para produtores e técnicos que conduzem campos de produção de sementes e úteis aos analistas que realizam análises de pureza em laboratórios oficiais e particulares de sementes.bitstream/CNPAF-2009-09/28149/1/doc_226.pd
Non-Hermitian Hamiltonians with real eigenvalues coupled to electric fields: from the time-independent to the time dependent quantum mechanical formulation
We provide a reviewlike introduction into the quantum mechanical formalism
related to non-Hermitian Hamiltonian systems with real eigenvalues. Starting
with the time-independent framework we explain how to determine an appropriate
domain of a non-Hermitian Hamiltonian and pay particular attention to the role
played by PT-symmetry and pseudo-Hermiticity. We discuss the time-evolution of
such systems having in particular the question in mind of how to couple
consistently an electric field to pseudo-Hermitian Hamiltonians. We illustrate
the general formalism with three explicit examples: i) the generalized Swanson
Hamiltonians, which constitute non-Hermitian extensions of anharmonic
oscillators, ii) the spiked harmonic oscillator, which exhibits explicit
supersymmetry and iii) the -x^4-potential, which serves as a toy model for the
quantum field theoretical phi^4-theory.Comment: 14 pages, 3 figures, to appear in Laser Physics, minor typos
correcte
PT-symmetric deformations of Calogero models
We demonstrate that Coxeter groups allow for complex PT-symmetric deformations across the boundaries of all Weyl chambers. We compute the explicit deformations for the A2 and G2-Coxeter group and apply these constructions to Calogero–Moser–Sutherland models invariant under the extended Coxeter groups. The eigenspectra for the deformed models are real and contain the spectra of the undeformed case as subsystems
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