18,292 research outputs found
Crystal structure and physical properties of EuPtIn intermetallic antiferromagnet
We report the synthesis of EuPtIn single crystalline platelets by the
In-flux technique. This compound crystallizes in the orthorhombic Cmcm
structure with lattice parameters \AA, \AA and
\AA. Measurements of magnetic susceptibility, heat capacity,
electrical resistivity, and electron spin resonance (ESR) reveal that
EuPtIn is a metallic Curie-Weiss paramagnet at high temperatures and
presents antiferromagnetic (AFM) ordering below K. In addition, we
observe a successive anomaly at K and a spin-flop transition at
T applied along the -plane. In the paramagnetic state, a
single Eu Dysonian ESR line with a Korringa relaxation rate of Oe/K is observed. Interestingly, even at high temperatures, both ESR
linewidth and electrical resistivity reveal a similar anisotropy. We discuss a
possible common microscopic origin for the observed anisotropy in these
physical quantities likely associated with an anisotropic magnetic interaction
between Eu 4 electrons mediated by conduction electrons.Comment: 5 pages, 5 figure
Hemispherical power asymmetries in the WMAP 7-year low-resolution temperature and polarization maps
We test the hemispherical power asymmetry of the WMAP 7-year low-resolution
temperature and polarization maps. We consider two natural estimators for such
an asymmetry and exploit our implementation of an optimal angular power
spectrum estimator for all the six CMB spectra. By scanning the whole sky
through a sample of 24 directions, we search for asymmetries in the power
spectra of the two hemispheres, comparing the results with Monte Carlo
simulations drawn from the WMAP 7-year best-fit model. Our analysis extends
previous results to the polarization sector. The level of asymmetry on the ILC
temperature map is found to be compatible with previous results, whereas no
significant asymmetry on the polarized spectra is detected. Moreover, we show
that our results are only weakly affected by the a posteriori choice of the
maximum multipole considered for the analysis. We also forecast the capability
to detect dipole modulation by our methodology at Planck sensitivity.Comment: 7 pages, 9 figures. Accepted for publication in MNRA
Assessing the influence of the carbon oxidation-reduction state on organic pollutant biodegradation in algal-bacterial photobioreactors
The influence of the carbon oxidation-reduction state (CORS) of organic pollutants on their biodegradation in enclosed algal-bacterial photobioreactors was evaluated using a consortium of enriched wild-type methanotrophic bacteria and microalgae. Methane, methanol and glucose (with CORS -4, -2 and 0, respectively) were chosen as model organic pollutants. In the absence of external oxygen supply, microalgal photosynthesis was not capable of supporting a significant methane and methanol biodegradation due to their high oxygen demands per carbon unit, while glucose was fully oxidized by photosynthetic oxygenation. When bicarbonate was added, removal efficiencies of 37¿±¿4% (20 days), 65¿±¿4% (11 days) and 100% (2 days) were recorded for CH(4,) CH(3)OH and C(6)H(12)O(6), respectively due to the additional oxygen generated from photosynthetic bicarbonate assimilation. The use of NO(3)(-) instead of NH(4)(+) as nitrogen source (N oxidation-reduction state of +5 vs. -3) resulted in an increase in CH(4) degradation from 0 to 33¿±¿3% in the absence of bicarbonate and from 37¿±¿4% to 100% in the presence of bicarbonate, likely due to a decrease in the stoichiometric oxygen requirements and the higher photosynthetic oxygen production. Hypothetically, the CORS of the substrates might affect the CORS of the microalgal biomass composition (higher lipid content). However, the total lipid content of the algal-bacterial biomass was 19¿±¿7% in the absence and 16¿±¿2% in the presence of bicarbonat
The effect of the environment on the Faber Jackson relation
We investigate the effect of the environment on the Faber Jackson (FJ)
relation, using a sample of 384 nearby elliptical galaxies and estimating
objectively their environment on the typical scale of galaxy clusters. We show
that the intrinsic scatter of the FJ is significantly reduced when ellipticals
in high density environments are compared to ellipticals in low density ones.
This result, which holds on a limited range of overdensities, is likely to
provide an important observational link between scaling relations and formation
mechanisms in galaxies.Comment: accepted by Ap
Hadronic decays of the tau lepton into K K pion modes within Resonance Chiral Theory
Tau decays into hadrons have a twofold interest: On the one hand, they are a
clean environment for studying the hadronization of the left-handed current of
QCD, while, on the other side, provide relevant dynamical information of the
resonances that mediate these processes. Within an effective field theory-like
framework, namely Resonance Chiral Theory, we analyse the decays ot the tau
into K K pion modes and compare the results with CLEO and BaBar data. In this
way, we provide bounds on the couplings entering our Lagrangian and predict the
corresponding spectral functions. As a main result -and contrary to the bulk of
theoretical studies and experimental analyses- we find vector current dominance
on these decays.Comment: 7 pages, 1 figure, Prepared for the conference QCD@Work07 in Martina
Franca, Bari, Italy. To appear in the Proceeding
Água-de-coco: métodos de conservação.
Atualmente, a cocoicultura e considerada a segunda cultura frutifera de importancia economica na regiao Nordeste brasileira, tendo os Tabuleiros Costeiros como maiores produtores. Em meados de 1990, ocorreu uma busca acirrada por produtos de coco oriundos ded paises africanos e asiaticos que trabalham com culturas subsidiadas (Sri Lanka, Costa do Marfin, Indonesia e Felipinas). O preco atrativo nao permitia a concorrencia com os produtos de origem nacional, levando os produtos de coco da regiao a situacoes de inviabilizacao de suas culturas. (...) Atualmente, a agua de coco verde consiste em um grande ramo de comercializacao de cocos da variedade anã verde, com acessos notadamente a mercados distantes dos produtores.bitstream/CNPAT-2010/4873/1/Dc-037.pd
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