9,607 research outputs found
On Weierstra{\ss} semigroups at one and two points and their corresponding Poincar\'e series
The aim of this paper is to introduce and investigate the Poincar\'e series
associated with the Weierstra{\ss} semigroup of one and two rational points at
a (not necessarily irreducible) non-singular projective algebraic curve defined
over a finite field, as well as to describe their functional equations in the
case of an affine complete intersection.Comment: Beginning of Section 3 and Subsection 3.1 were modifie
Effect of Solution pH on the Removal of Paracetamol by Activated Carbon of Dende Coconut Mesocarp
Activated carbon of dende coconut mesocarp was used to investigate the removal of paracetamol from water by adsorption. The results indicated that the retention of paracetamol was favored in activated carbon with neutral surface properties. The textural features and presence of a transport pores network contributed to ensuring the accessibility to the inner porosity, and the microporosity must be large enough to accommodate the paracetamol molecule. Chemisorption and mainly physisorption are important in the
paracetamol removal. Pseudo-second order equation and Langmuir model were chosen to best present the experimental data. The adsorption process was non-spontaneous and endothermic with increase in system disorder
Searches for Lepton Flavour Violation at a Linear Collider
We investigate the prospects for detection of lepton flavour violation in
sparticle production and decays at a Linear Collider (LC), in models guided by
neutrino oscillation data. We consider both slepton pair production and
sleptons arising from the cascade decays of non-leptonic sparticles. We study
the expected signals when lepton-flavour-violating (LFV) interactions are
induced by renormalization effects in the Constrained Minimal Supersymmetric
extension of the Standard Model (CMSSM), focusing on the subset of the
supersymmetric parameter space that also leads to cosmologically interesting
values of the relic neutralino LSP density. Emphasis is given to the
complementarity between the LC, which is sensitive to mixing in both the left
and right slepton sectors, and the LHC, which is sensitive primarily to mixing
in the right sector. We also emphasize the complementarity between searches for
rare LFV processes at the LC and in low-energy experiments.Comment: 19 pages, 10 figure
Avaliação da produtividade agrícola da cana-planta e cana-soca sob diferentes espaçamentos entre plantas para produção de açúcar e etanol.
Para avaliar a influência da variação do espaçamento entre linhas na produtividade e na qualidade da cana-de-açúcar para produção de etanol e açúcar foi instalado um experimento em gleba sob reforma na área agrícola da Usina Renuka - Unidade Madhu. Tal unidade sucroalcooleira, localizada na Bacia do Médio Rio Tietê, com área agrícola no Município de Guaiçara, SP, é uma das cinco maiores do mundo, com capacidade de moagem de 6,5 milhões de toneladas de cana-de-açúcar por ano.bitstream/item/146625/1/BolPesq40-Silva.pd
Magnetic Properties of Weakly Doped Antiferromagnets
We study the spin excitations and the transverse susceptibility of a
two-dimensional antiferromagnet doped with a small concentration of holes in
the t-J model. The motion of holes generates a renormalization of the magnetic
properties. The Green's functions are calculated in the self-consistent Born
approximation. It is shown that the long-wavelength spin waves are
significantly softened and the shorter-wavelength spin waves become strongly
damped as the doping increases. The spin wave velocity is reduced by the
coherent motion of holes, and not increased as has been claimed elsewhere. The
transverse susceptibility is found to increase considerably with doping, also
as a result of coherent hole motion. Our results are in agreement with
experimental data for the doped copper oxide superconductors.Comment: 20 page
Adaptabilidade e estabilidade de híbridos de milho na região Meio-Norte do Brasil na safra 2007-2008.
A seleção de cultivares de alto potencial para a produtividade de grãos, elevada estabilidade de produção aliada às características agronômica superiores é o principal objetivo da maioria dos programas de melhoramento genético vegetal. O objetivo deste trabalho foi estimar a adaptabilidade e a estabilidade de híbridos de milho no Meio-Norte brasileiro. Dados experimentais da produtividade de grãos obtidos em diversos ambientes do Meio-Norte do Brasil, na safra 2007-2008, foram avaliados. Foi utilizado o delineamento de bloco ao acaso, composto por 42 tratamentos, e duas repetições. Para a estimativa dos parâmetros de adaptabilidade e estabilidade utilizou-se o método de Cruz et al. (1989). Os híbridos que expressam adaptabilidade ampla tornam-se de grande interesse para exploração nos diferentes sistemas de produção presentes na região
Covariant Description of Flavor Conversion in the LHC Era
A simple covariant formalism to describe flavor and CP violation in the
left-handed quark sector in a model independent way is provided. The
introduction of a covariant basis, which makes the standard model approximate
symmetry structure manifest, leads to a physical and transparent picture of
flavor conversion processes. Our method is particularly useful to derive robust
bounds on models with arbitrary mechanisms of alignment. Known constraints on
flavor violation in the K and D systems are reproduced in a straightforward
manner. Assumptions-free limits, based on top flavor violation at the LHC, are
then obtained. In the absence of signal, with 100 fb^{-1} of data, the LHC will
exclude weakly coupled (strongly coupled) new physics up to a scale of 0.6 TeV
(7.6 TeV), while at present no general constraint can be set related to Delta
t=1 processes. LHC data will constrain Delta F=2 contributions via same-sign
tops signal, with a model independent exclusion region of 0.08 TeV (1.0 TeV).
However, in this case, stronger bounds are found from the study of CP violation
in D-bar D mixing with a scale of 0.57 TeV (7.2 TeV). In addition, we apply our
analysis to models of supersymmetry and warped extra dimension. The minimal
flavor violation framework is also discussed, where the formalism allows to
distinguish between the linear and generic non-linear limits within this class
of models.Comment: 24 pages, 6 figures. Some corrections and clarifications; references
added. Matches published versio
Charged lepton Flavor Violation in Supersymmetry with Bilinear R-Parity Violation
The simplest unified extension of the Minimal Supersymmetric Standard Model
with bi-linear R-parity violation naturally predicts a hierarchical neutrino
mass spectrum, suitable to explain atmospheric and solar neutrino fluxes. We
study whether the individual violation of the lepton numbers L_{e,mu,tau} in
the charged sector can lead to measurable rates for BR(mu->e gamma)and
$BR(tau-> mu gamma). We find that some of the R-parity violating terms that are
compatible with the observed atmospheric neutrino oscillations could lead to
rates for mu->e gamma measurable in projected experiments. However, the Delta
m^2_{12} obtained for those parameters is too high to be compatible with the
solar neutrino data, excluding therefore the possibility of having measurable
rates for mu->e gamma in the model.Comment: 29 pages, 8 figures. Constraint from solar neutrino data included,
conclusions changed respect v
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