16,653 research outputs found
Deformation method for generalized Abelian Higgs-Chern-Simons models
We present an extension of the deformation method applied to self-dual
solutions of generalized Abelian Higgs-Chern-Simons models. Starting from a
model defined by a potential and a non-canonical kinetic term
whose analytical domain wall solutions are
known, we show that this method allows to obtain an uncountable number of new
analytical solutions of new models defined by other functions
and . We present some examples of deformation functions
leading to new families of models and their associated analytic solutions.Comment: 6 pages, 10 figure
Topological vortices in generalized Born-Infeld-Higgs electrodynamics
A consistent BPS formalism to study the existence of topological axially
symmetric vortices in generalized versions of the Born-Infeld-Higgs
electrodynamics is implemented. Such a generalization modifies the field
dynamics via introduction of three non-negative functions depending only in the
Higgs field, namely, , and . A set of
first-order differential equations is attained when these functions satisfy a
constraint related to the Ampere law. Such a constraint allows to minimize the
system energy in such way that it becomes proportional to the magnetic flux.
Our results provides an enhancement of topological vortex solutions in
Born-Infeld-Higgs electrodynamics. Finally, we analyze a set of models such
that a generalized version of Maxwell-Higgs electrodynamics is recovered in a
certain limit of the theory.Comment: 8 pages, 8 figures, to appear in EPJ
Estudos para definição de meios de cultura e métodos de desinfestação de explantes de plantas adultas de erva-mate (Ilex paraguarienses St. Hill).
Este trabalho é o resultado de uma série de estudos objetivando avaliar os efeitos de diferentes tratamentos (desinfestantes, antioxidantes, bactericidas, reguladores de crescimento e meios de cultura) na desinfestação e no controle da oxidação para o estabelecimento in vitro de explantes de erva-mate (Ilex paraguariensis), procedentes de árvores de 8 anos de idade, de Colombo - PR. A avaliação dos experimentos foi realizada sete dias após sua introdução in vitro, sendo verificadas grandes taxas gerais de contaminação por fungos e bactérias, bem como, a ocorrência de oxidação nos explantes. De forma geral, conclui-se que o hipoclorito de sódio a 1,5%, com tempo de imersão de 30 minutos e o etanol (álcool 70%) a dois minutos em explantes oriundos de brotações de mudas enxertadas foram os que proporcionaram os melhores resultados.Secão: Conservação, Melhoramento e Multiplicação. Feira do Agronegócio da Erva-mate, 1., 2003, Chapecó. Integrar para promover o agronegócio da erva-mate
Dynamical evolution of V-type asteroids in the central main belt
V-type asteroids are associated with basaltic composition, and are supposed
to be fragments of crust of differentiated objects. Most V-type asteroids in
the main belt are found in the inner main belt, and are either current members
of the Vesta dynamical family (Vestoids), or past members that drifted away.
However, several V-type photometric candidates have been recently identified in
the central and outer main belt.
The origin of this large population of V-type objects is not well understood.
Since it seems unlikely that Vestoids crossing the 3J:-1A mean-motion resonance
with Jupiter could account for the whole population of V-type asteroids in the
central and outer main belt, origin from local sources, such as the parent
bodies of the Eunomia, and of the Merxia and Agnia asteroid families, has been
proposed as an alternative mechanism.
In this work we investigated the dynamical evolution of the V-type
photometric candidates in the central main belt, under the effect of
gravitational and non-gravitational forces. Our results show that dynamical
evolution from the parent bodies of the Eunomia and Merxia/Agnia families on
timescales of 2 Byr or more could be responsible for the current orbital
location of most of the low-inclined V-type asteroids.Comment: 16 pages, 10 figures, 3 tables. Accepted for publication in MNRA
Organização da informação sobre o método de coordenação da qualidade na cadeia de processamento mínimo da alface americana.
Visando contribuir para o modelo de coordenação da qualidade de vegetais minimamente processados, no âmbito do projeto "Transferência de um novo modelo de coordenação da qualidade para a cadeia de produção de hortaliças minimamente processadas" (ALVARENGA, 2008), a Embrapa está reunindo, organizando e armazenando informações e tecnologias geradas pela empresa e por outras instituições de pesquisa relevantes ao segmento de VMP para, posteriormente, disponibilizá-las na internet. O presente trabalho relata esta experiência
- …