538 research outputs found
Matrizes de contabilidade social (SAM) para o Brasil de 1990 a 2005
Bibliografia: p. 358-359Este texto descreve como foi construĂdo um conjunto consistente de matrizes de contabilidade social (SAM) para o Brasil, para os anos de 1990 a 2005. A metodologia empregada Ă© uma adaptação e aprimoramento daquela utilizada para a construção da SAM 2003, descrita em Tourinho, Silva e Alves (2006). O objetivo das principais extensĂ”es Ă© detalhar o papel do sistema financeiro na transferĂȘncia de poupança entre entidades da economia e assegurar a consistĂȘncia intertemporal das tabelas de dados suplementares Ă s contas nacionais. Ademais, a metodologia foi empregada de modo sistemĂĄtico e uniforme para todos os anos e, portanto, o conjunto de SAMs Ă© consistente para todo o perĂodo considerado. Para cada ano, foram obtidas matrizes a preços correntes e a preços do ano anterior, que permitem decompor a variação entre dois anos consecutivos entre aquelas devidas a variaçÔes de quantidades e aquelas devidas a variaçÔes de preços. O conjunto completo de matrizes Ă© disponibilizado em formato eletrĂŽnico no endereço http://www.bndes.gov.br.This text describes how a set of Social Accounting Matrices (SAM) spanning the period 1990 to 2005 was constructed for Brazil. The methodology employed is an adaptation and improvement of the one used in the construction of the SAM for 2003, described in Tourinho, Silva e Alves (2006). The objective of the main extensions is to detail the role of the fi nancial system in transferring savings between diferente entities of the economy, and to insure that the tables of supplementary data to the national accounts are consistente from the intertemporal perspective. In addition, the methodology was employed in a systematic and uniform manner for all years, so that the set of SAMs is consistent for the complete period considered. For all years we obtained matrices at current prices and at previous year prices, which allows the decomposition of the variation in two successive years between those that are due to quantity variations and those due to price changes. The complete set of matrices is available in electronic format at the web address: http://www.bndes.gov.br
EFEITOS DE CONSEQUĂNCIAS CULTURAIS SOBRE A SELEĂĂO E MANUTENĂĂO DE DUAS PRĂTICAS CULTURAIS ALTERNADAS
Metacontingencies describe functional relations among interlocked behavioral contingencies, their aggregated products and cultural consequences. The present study investigated the effects of cultural consequences on the selection, maintenance and transmission of two alternating cultural practices. Undergraduate students were exposed to an ABABC experimental design, in which in conditions A and B different metacontingencies were operating and in C the cultural consequence was suspended. The individual and cultural consequences used were different in nature. The results showed the selection of the target cultural practices in the second exposures to the conditions (A and B). These data are discussed considering the amount of exposure to the metacontingencies and the probability of occurrence of the interlocking behavioral contingencies and their aggregated products described in each metacontingency. Keywords: cultural selection, cultural transmission, metacontingency. MetacontingĂȘncias descrevem relaçÔes funcionais entre contingĂȘncias comportamentais entrelaçadas com seus produtos agregados e consequĂȘncias culturais. O presente estudo investigou os efeitos de consequĂȘncias culturais na seleção, manutenção e transmissĂŁo de duas prĂĄticas culturais alternadas. Estudantes universitĂĄrios foram expostos a um delineamento ABABC, em que nas condiçÔes A e B vigoraram metacontingĂȘncias distintas e na C houve suspensĂŁo de consequĂȘncias culturais. Foram utilizadas consequĂȘncias individuais e culturais de naturezas distintas. Os resultados indicaram seleção de prĂĄticas culturais alvo na segunda exposição a cada condição (A e B). Esses dados sĂŁo discutidos considerando-se a quantidade de exposição Ă s metacontingĂȘncias e a probabilidade de ocorrĂȘncia das contingĂȘncias comportamentais entrelaçadas e seus produtos agregados descritos em cada metacontingĂȘncia.
Palavras-chave: seleção cultural, transmissĂŁo cultural, metacontingĂȘncia
Raman study of ionic water-based copper and zinc ferrite magnetic #uids
Abstract Raman spectroscopy is used to investigate the OH-bending and OH-stretching modes of chemisorbed OH-groups in copper-ferrite and zinc-ferrite water-based magnetic #uid samples. Room-temperature Raman spectra were taken from diluted magnetic #uid samples and compared with the spectrum taken from liquid water. The suppression of the symmetric OH-stretching Raman modes from the ionic magnetic #uid sample spectra is discussed in terms of the replacement of a hydrogen atom from the water molecule by the nanoparticle surface. Moreover, changes on the area ratio between hydrogen bonded and nonhydrogen bonded OH-Raman peaks in the ionic magnetic #uid samples, as compared to the OH-Raman peaks from liquid water, are discussed in terms of changes on the hydrogen bond strength. 1999 Elsevier Science B.V. All rights reserved. Keywords: Raman spectroscopy; Magnetic #uids; Hydrogen bond; Chemisorption Magnetic #uids are ultra-stable colloidal systems consisting of monodomain magnetic nanoparticles dispersed in organic or inorganic liquid carrier. The stability of magnetic #uids is achieved through the balance between opposite particle interaction tendencies. From one side, particle thermal motion and particle}particle repulsion work together to keep particles apart. From the other side, Van der Waals and magnetic dipole interaction tend to stick particles together. Di!erent repulsion mechanisms are used to prevent particle}particle clustering, thus responding for di!erent types of magnetic * Corresponding author. Fax: #55-61-2723151. E-mail address: pcmor@"s.unb.br (P.C. Morais) #uids. Steric repulsion prevents agglomeration in surfacted magnetic #uids, whereas coulombic repulsion accounts for stability in ionic magnetic #uids [1]. High resolution microscopy, X-ray diffraction, magnetization measurements and optical birefringence measurements are the magnetic #uid standard characterization technique
Lyotropic ferronematic liquid crystals based on new Ni, Cu and Zn Ionic magnetic fluids
Rare earth doped maghemite EDL-MF: a perspective for nanoradiotherapy?
Abstract We report on electric double layered magnetic fluids based on samarium-doped maghemite nanoparticles. The nanostructures chemical composition is carefully checked and X-ray diffraction patterns provide both their mean size and a structural characterization. Magnetization results are presented. Since these particles can become radioactive after neutron activation, they could therefore represent a new perspective for biomedical applications.
Study of charmonium production in b -hadron decays and first evidence for the decay Bs0
Using decays to Ï-meson pairs, the inclusive production of charmonium states in b-hadron decays is studied with pp collision data corresponding to an integrated luminosity of 3.0 fbâ1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting byBC ⥠B(b â C X) Ă B(C â ÏÏ) the inclusive branching fraction of a b hadron to a charmonium state C that decays into a pair of Ï mesons, ratios RC1C2 ⥠BC1 /BC2 are determined as RÏc0ηc(1S) = 0.147 ± 0.023 ± 0.011, RÏc1ηc(1S) =0.073 ± 0.016 ± 0.006, RÏc2ηc(1S) = 0.081 ± 0.013 ± 0.005,RÏc1 Ïc0 = 0.50 ± 0.11 ± 0.01, RÏc2 Ïc0 = 0.56 ± 0.10 ± 0.01and Rηc(2S)ηc(1S) = 0.040 ± 0.011 ± 0.004. Here and below the first uncertainties are statistical and the second systematic.Upper limits at 90% confidence level for the inclusive production of X(3872), X(3915) and Ïc2(2P) states are obtained as RX(3872)Ïc1 < 0.34, RX(3915)Ïc0 < 0.12 andRÏc2(2P)Ïc2 < 0.16. Differential cross-sections as a function of transverse momentum are measured for the ηc(1S) andÏc states. The branching fraction of the decay B0s â ÏÏÏ is measured for the first time, B(B0s â ÏÏÏ) = (2.15±0.54±0.28±0.21B)Ă10â6. Here the third uncertainty is due to the branching fraction of the decay B0s â ÏÏ, which is used for normalization. No evidence for intermediate resonances is seen. A preferentially transverse Ï polarization is observed.The measurements allow the determination of the ratio of the branching fractions for the ηc(1S) decays to ÏÏ and p p asB(ηc(1S)â ÏÏ)/B(ηc(1S)â p p) = 1.79 ± 0.14 ± 0.32
Observation of an Excited Bc+ State
Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+Ï+Ï- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bcâ(2S31)+ state reconstructed without the low-energy photon from the Bcâ(1S31)+âBc+Îł decay following Bcâ(2S31)+âBcâ(1S31)+Ï+Ï-. A second state is seen with a global (local) statistical significance of 2.2Ï (3.2Ï) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date
Bose-Einstein correlations of same-sign charged pions in the forward region in pp collisions at âs=7 TeV
Bose-Einstein correlations of same-sign charged pions, produced in protonproton collisions at a 7 TeV centre-of-mass energy, are studied using a data sample collected
by the LHCb experiment. The signature for Bose-Einstein correlations is observed in the
form of an enhancement of pairs of like-sign charged pions with small four-momentum
difference squared. The charged-particle multiplicity dependence of the Bose-Einstein correlation parameters describing the correlation strength and the size of the emitting source
is investigated, determining both the correlation radius and the chaoticity parameter. The
measured correlation radius is found to increase as a function of increasing charged-particle
multiplicity, while the chaoticity parameter is seen to decreas
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