16,205 research outputs found
Estudos da ocorrência de fungos micorrizicos arbusculares e do potencial infectivo em espécies nativas da caatinga, na região de Petrolina, Pernambuco
O objetivo deste trabalho foi ampliar os conhecimentos sobre a associação micorrizica (número de glomerosporos, potencial de infectividade do solo, percentual de colonização e diversidade de FMA) em plantas nativas da caatinga
Simbiose micorrízica em plantas forrageiras.
Esse projeto teve como objetivos: verificar a condição micorrízica em plantas forrageiras nas condições do semi-árido, avaliar a eficiência de fungos micorrízicos arbusculares em promover o crescimento vegetal e o teor nutricional de plantas de Cajanus cajan var. Petrolina, passível de utilização na alimentação animal, e conhecer o potencial dessas forragens em incrementar a propagação desses fungos no solo
Associação micorrízica em plantas nativas da caatinga: ocorrência e eficiência simbiótica para produção de mudas.
O objetivo deste trabalho foi ampliar os conhecimentos sobre a associação micorrizica (número de glomerosporos, potencial de infectividade do solo, percentual de colonização e diversidade de FMA) em plantas nativas da caatinga, assim como avaliar o efeito do regime hídrico sobre a reprodução desses fungos
Resposta de plantas forrageiras à inoculação com fungos micorrízicos arbusculares (FMA) e bactérias fixadoras de nitrogênio (FBN): simbiose e eficiência no crescimento vegetal sob condições semi-áridas.
O presente trabalho teve por objetivos avaliar a condição micorrízica no campo das variedades Petrolina e Forrageiro de Cajanus cajan e a eficiência da inoculação com fungos micorrízicos arbusculares (FMA) e BFN no crescimento dessa forrageira em dois tipos de solo
Modeling Quasi-Static and Fatigue-Driven Delamination Migration
An approach was proposed and assessed for the high-fidelity modeling of progressive damage and failure in composite materials. It combines the Floating Node Method (FNM) and the Virtual Crack Closure Technique (VCCT) to represent multiple interacting failure mechanisms in a mesh-independent fashion. Delamination, matrix cracking, and migration were captured failure and migration criteria based on fracture mechanics. Quasi-static and fatigue loading were modeled within the same overall framework. The methodology proposed was illustrated by simulating the delamination migration test, showing good agreement with the available experimental data
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
The unfriendly ISM in the radio galaxy 4C12.50 (PKS 1345+12)
The radio source 4C12.50 has often been suggested to be a prime candidate for
the link between ultraluminous infrared galaxies and young radio galaxies. A
VLBI study of the neutral hydrogen in the nuclear regions of this object shows
that most of the gas detected close to the systemic velocity is associated with
an off-nuclear cloud (~50 to 100 pc from the radio core) with a column density
of ~10^22 T_spin/100 K) cm^(-2) and an HI mass of a few times 10^5 to 10^6
M_sun. We consider a number of possibilities to explain the results. In
particular, we discus the possibility that this cloud indicates the presence of
a rich and clumpy interstellar medium in the centre, likely left over from the
merger that triggered the activity and that this medium influences the growth
of the radio source. The location of the cloud -- at the edge of the northern
radio jet/lobe -- suggests that the radio jet might be interacting with a gas
cloud. This interaction could be responsible for bending the young radio jet.
The velocity profile of the gas is relatively broad (~150$ km/s) and we
interpret this as kinematical evidence for interaction of the radio plasma with
the cloud. We also consider the model where the cloud is part of a broader
circumnuclear structure. Only a limited region of this structure would have
sufficient background radio brightness and large enough column depth in neutral
gas to obtain detectable HI absorption against the counterjet. The VLBI study
of the neutral hydrogen in 4C12.50 suggests that HI detected near the systemic
velocity (as it is often the case in radio galaxies) may not necessarily be
connected with a circumnuclear disk or torus (as is very often assumed) but
instead could be a tracer of the large-scale medium that surrounds the active
nucleus and that may influence the growth of the young radio source.Comment: 7 pages, 2 figures. Accepted for publication in A&
Slepton mass-splittings as a signal of LFV at the LHC
Precise measurements of slepton mass-splittings might represent a powerful
tool to probe supersymmetric (SUSY) lepton flavour violation (LFV) at the LHC.
We point out that mass-splittings of the first two generations of sleptons are
especially sensitive to LFV effects involving transitions. If these
mass-splittings are LFV induced, high-energy LFV processes like the neutralino
decay {\nt}_2\to\nt_1\tau^{\pm}\mu^{\mp} as well as low-energy LFV processes
like are unavoidable. We show that precise slepton
mass-splitting measurements and LFV processes both at the high- and low-energy
scales are highly complementary in the attempt to (partially) reconstruct the
flavour sector of the SUSY model at work. The present study represents another
proof of the synergy and interplay existing between the LHC, i.e. the {\em
high-energy frontier}, and high-precision low-energy experiments, i.e. the {\em
high-intensity frontier}.Comment: 11 pages, 5 figures. v2: added discussion on backgrounds, added
references, version to be published on JHE
- …