1,057 research outputs found
Sensitivity analysis of surface ozone to modified initial and boundary conditions in both rural and industrial zones
International audienceA three-dimensional air quality model based on a set of chemical species mass conservation equations describes the time evolution of chemical species in the atmosphere. In order to solve this set of equations, proper choices of initial and boundary conditions are needed. Ideally, initial and boundary conditions should be determined on the basis of observations. However, since such high-resolution observations are generally not available, it becomes necessary to use other information sources to specify the initial and boundary values. The fact that both the initial and the boundary conditions are specified with some degree of presumption makes it important to evaluate their influence in the model results. In this paper we present a study of the impact of initial and boundary concentrations on the modelled surface ozone concentration over two environments: Huelva and Badajoz, an industrial and a rural zone, respectively. The impacts are analysed for the same meteorological period (10?15 August 2003)
Detecting transient gravitational waves in non-Gaussian noise with partially redundant analysis methods
There is a broad class of astrophysical sources that produce detectable,
transient, gravitational waves. Some searches for transient gravitational waves
are tailored to known features of these sources. Other searches make few
assumptions about the sources. Typically events are observable with multiple
search techniques. This work describes how to combine the results of searches
that are not independent, treating each search as a classifier for a given
event. This will be shown to improve the overall sensitivity to
gravitational-wave events while directly addressing the problem of consistent
interpretation of multiple trials.Comment: 11 pages, 5 figure
Stripe charge ordering in SrO-terminated SrTiO3(001) surfaces
The local electronic structure of the SrO-terminated SrTiO3(001) surface was
explored using scanning tunneling microscopy. At low bias voltages in the empty
states, a unidirectional structure with a periodicity of 3 unit cells,
superimposed on a c(2 x 2) reconstructed structure, was found to develop along
the crystallographic a axis. This structure indicates a charge-ordered stripe
induced by carrier doping from oxygen vacancies in the SrO and the subsurface
TiO2 planes. In the filled states, localized deep in-gap states were observed
in addition to large energy gaps in the tunneling spectra. This result
represents inelastic tunneling due to significant electron-lattice interaction
associated with unidirectional lattice distortion in the SrO-terminated
surface.Comment: 6 pages, 5 figures, accepted for publication in PR
Likelihood-ratio ranking of gravitational-wave candidates in a non-Gaussian background
We describe a general approach to detection of transient gravitational-wave
signals in the presence of non-Gaussian background noise. We prove that under
quite general conditions, the ratio of the likelihood of observed data to
contain a signal to the likelihood of it being a noise fluctuation provides
optimal ranking for the candidate events found in an experiment. The
likelihood-ratio ranking allows us to combine different kinds of data into a
single analysis. We apply the general framework to the problem of unifying the
results of independent experiments and the problem of accounting for
non-Gaussian artifacts in the searches for gravitational waves from compact
binary coalescence in LIGO data. We show analytically and confirm through
simulations that in both cases the likelihood ratio statistic results in an
improved analysis.Comment: 10 pages, 6 figure
Fatores afetando o consumo e utilização de forrageiras de baixa qualidade por ruminantes - revisão.
A quantidade máxima de alimento capaz de ser consumida por um ruminante e de grande importância para o produtor. De um modo geral, quanto maior for o consumo, menor será a quantidade de alimento necessário por unidade de produção. Este fato e que caracteriza a eficiência produtiva de um animal. A conseqüência econômica seria que maiores lucros estariam dependentes da capacidade dos ruminantes em digerir alimentos fibrosos mais baratos e disponÃveis em maiores quantidades. O Maximo consumo de uma forragem pelo ruminante depende, primariamente, das taxas de escoamento do rúmen da celulose e hemicelulose. Estas taxas, por sua vez, depende de vários fatores que interferem na atividade da flora microbiana do rúmen, quais sejam: evolução do processo de lignificação com o estágio de maturação das forrageiras, parcial ausência de nutrientes para a microflora como nitrogênio ou minerais e a presença em excesso de agentes bacteriostáticos. Dada a sua importância econômica e cientifica, este assunto vem sendo estudado extensivamente por nutricionistas e fisiologistas em varias partes do mundo, gerando uma enorme gama de conceitos relacionados ao binômio animal-planta, parte dos quais foram reunidos no presente trabalho de revisão.bitstream/item/131377/1/fatores-afetando-o-consumo.pd
A Beta Beam complex based on the machine upgrades for the LHC
The Beta Beam CERN design is based on the present LHC injection complex and
its physics reach is mainly limited by the maximum rigidity of the SPS. In
fact, some of the scenarios for the machine upgrades of the LHC, particularly
the construction of a fast cycling 1 TeV injector (``Super-SPS''), are very
synergic with the construction of a higher Beta Beam. At the energies
that can be reached by this machine, we demonstrate that dense calorimeters can
already be used for the detection of at the far location. Even at
moderate masses (40 kton) as the ones imposed by the use of existing
underground halls at Gran Sasso, the CP reach is very large for any value of
that would provide evidence of appearance at T2K or
NOA (). Exploitation of matter effects at the
CERN to Gran Sasso distance provides sensitivity to the neutrino mass hierarchy
in significant areas of the plane
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