1,268 research outputs found
N*(1535) electroproduction at high Q2
A covariant spectator quark model is applied to study the gamma N -> N*(1535)
reaction in the large Q2 region. Starting from the relation between the nucleon
and N*(1535) systems, the N*(1535) valence quark wave function is determined
without the addition of any parameters. The model is then used to calculate the
gamma N -> N*(1535) transition form factors. A very interesting, useful
relation between the A12 and S12 helicity amplitudes for Q2 > GeV^2, is also
derived.Comment: Contribution to the proceedings of the 8th International Workshop on
the Physics of Excited Nucleons (NSTAR2011), Jefferson Lab, Newport News, VA,
USA, May 17-20, 201
A relativistic quark model for the Omega- electromagnetic form factors
We compute the Omega- electromagnetic form factors and the decuplet baryon
magnetic moments using a quark model application of the Covariant Spectator
Theory. Our predictions for the Omega- electromagnetic form factors can be
tested in the future by lattice QCD simulations at the physical strange quark
mass.Comment: 13 pages, 5 figure
About the efficiency behavior of the Portuguese manufacturing firms during the financial crisis
This work studies some effects of the World Financial Crisis on firms in terms of efficiency scores, by measuring how 23K units used inputs and produced outputs, obtained from a set of Portuguese manufacturing firms on three time periods: pre-crisis (2006-2008), pretroika (2009-2011) and troika (2012-2013). We adopt a non-parametric approach, which combines Multidirectional Efficiency Analysis (MEA) with other techniques as cluster analysis, principal component analysis and dimensionality testing, to examine three empirical hypotheses: H(1) the performance of the portuguese firms in the manufacturing sector has been adversely affected by the financial crisis felt in Portugal in the troika years; H(2) due to the financial crisis, the manufacturing sector acquired long-term debt deliberately; and H(3) the financial crisis has affected substantially the food subsector. The results indicate that H(1) is confirmed, but not totally, H(2) is confirmed and H(3) is rejected. We also found surprisingly good affine fittings between inputs and capital, and outputs and EBIT with really good p-values. Hence, we also propose a reduction of the dimensionality of the MEA model, when it is possible to apply model fitting. If the reduction results in one input and one output,
we give procedures to visualize and compare between efficiencies scores.info:eu-repo/semantics/publishedVersio
Identifying the Azobenzene/Aniline reaction intermediate on TiO2-(110) : a DFT Study
Density functional theory (DFT) calculations, both with and without dispersion corrections, have been performed to investigate the nature of the common surface reaction intermediate that has been shown to exist on TiO2(110) as a result of exposure to either azobenzene (C6H5N═NC6H5) or aniline (C6H5NH2). Our results confirm the results of a previous DFT study that dissociation of azobenzene into two adsorbed phenyl imide (C6H5N) fragments, as was originally proposed, is not energetically favorable. We also find that deprotonation of aniline to produce this surface species is even more strongly energetically disfavored. A range of alternative surface species has been considered, and while dissociation of azobenzene to form surface C6H4NH species is energetically favored, the same surface species cannot form from adsorbed aniline. On the contrary, adsorbed aniline is much the most stable surface species. Comparisons with experimental determinations of the local adsorption site, the Ti–N bond length, the molecular orientation, and the associated C 1s and N 1s photoelectron core level shifts are all consistent with the DFT results for adsorbed aniline and are inconsistent with other adsorbed species considered. Possible mechanisms for the hydrogenation of azobenzene required to produce this surface species are discussed
Selection of common bean inbred lines with tolerance to high moisture at harvest.
The occurrence of precipitation / rain in harvest bean causes damage to the product and reduces the yield. The main alternative to mitigate this problem is to obtain cultivars presenting low germination of beans in the pods under conditions of high moisture. The purpose of this study was to verify if there is genetic variability among the common bean inbred lines that are in the phase of recommendation for the South of Minas Gerais, Brazil in regard to tolerance to moisture after harvest, and identify traits that may be routinely used in selection of tolerant lines to these conditions. Ninety-five lines in the phase of recommendation by the Genetic Breeding Program from UFLA were used. After harvest, a sample of plants from each plot was removed for assessments of seed germination in the pods in a moist chamber and water absorption by pod and seed. Eight days after harvest, another sample was removed to assess seed appearance using a scoring scale. The data were submitted to analysis of variance and estimates of the Pearson phenotypic correlations were obtained among traits. Lines differ in relation to tolerance to moisture at the time of harvest, with those of higher tolerance having lighter colored seeds. The main difficulty in selection of common bean lines for tolerance to high moisture at harvest is the repeatability of the environmental conditions among crop seasons. The alternative is assessing the amount of water absorbed by pods
Seleção precoce para tipo de grão e suas implicações no potencial produtivo de progênies de feijoeiro.
O objetivo deste trabalho foi avaliar o efeito da seleção precoce para tipo de grão na variabilidade e potencial produtivo de progênies de feijoeiro. Para isso foram avaliadas progênies do cruzamento entre as linhagens P-180 (grãos tipo carioca) x Paraná (grãos pardos)
Occurrence of marine litter along abyssal areas of the Gloria Fracture Zone (NE Atlantic).
Marine litter pollution is a recognized form of anthropogenic
disturbance that affects widely the marine environment,
particularly near the continental margins, although also
present at abyssal and bathyal depths. This study reports the
occurrence of marine litter distribution and abundance in four
abyssal basins along the Gloria fracture zone in the NE
Atlantic. Litter items occurrences were analysed using TV-CTD
video surveys carried out during the multidisciplinary
activities of the R/V Meteor M162 cruise. The surveys reached
depths between 3500-4500m and covered 16 km of seafloor,
between the Terceira ridge and the Madeira-Tore Rise. Litter
items were annotated and categorized by type (i.e., plastic,
fishing gear, metal, glass, other unknown items). Results
revealed that litter was exclusively found on soft sediment
habitats across all areas, i.e. depositional areas, with the
overwhelming dominance of plastics items (71%), such as
plastic containers, cups and bag fragments. Although less
common (6-8%), metal, glass and lost fishing gear were also
observed. Litter density was on average 9 times higher in the
easternmost area near the Madeira-Tore ridge, when
compared to the other areas. Higher litter densities are likely
explained due to the proximity to the Madeira-Tore
seamount complex targeted by the fishing industry and
nearimportant corridors of marine traffic between various
Atlantic and Mediterranean locations
Seleção de progênies de feijoeiro com plantas eretas e grãos tipo carioca.
Para confirmar se a população oriunda do cruzamento CVIII-8511 x BRS-Supremo, identificada em um cruzamento dialélico anteriormente realizado é realmente promissora para a seleção de plantas eretas e com boa produtividade de grãos foi realizado o presente trabalho
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