Semi-classical Analysis of Spin Systems near Critical Energies

The spectral properties of $su(2)$ Hamiltonians are studied for energies near the critical classical energy $\varepsilon_c$ for which the corresponding classical dynamics presents hyperbolic points (HP). A general method leading to an algebraic relation for eigenvalues in the vicinity of $\varepsilon_c$ is obtained in the thermodynamic limit, when the semi-classical parameter $n^{-1}=(2s)^{-1}$ goes to zero (where $s$ is the total spin of the system). Two applications of this method are given and compared with numerics. Matrix elements of observables, computed between states with energy near $\varepsilon_c$, are also computed and shown to be in agreement with the numerical results

SOCIO-ENVIRONMENTAL DISCLOSURE AND LEGITIMACY: AN INVESTIGATION OVER THE MAJOR BRAZILIAN BANKS

This paper analyzes the relationship between sustainability and financial performances of the six biggest banks in Brazil. Brazilian banks were analyzed regarding their socio-environmental and economic disclosure. We collected socio-environmental data from annual reports, available on banks websites and financial data at Economática® database. Although disclosure data are not audited, which represents a limitation, these banks conduct their business in accordance with sustainable development policies and regulations, and publish information about initiatives. Methodological procedures include a content analysis, canonical correlation analysis and panel data regression providing a relationship assessment between variables. Results in this paper mostly showed a positive relationship between socio-environmental responsibility (SER) and financial performances, even considering the impacts of Brazilian crisis. The objective of this voluntary disclosure lays on companies’ legitimacy as a dialogue mechanism with society.This paper analyzes the connection between sustainability and financial performances of the six biggest banks in Brazil. Brazilian banks were analyzed regarding their socio-environmental and economic disclosure. We collected Socio-environmental data from annual reports, available on banks websites and financial data at Economática® database. Although disclosure data are not audited, which represents a limitation, these banks conduct their business in accordance with sustainable development policies and regulations, and publish information about initiatives. Spearman's non-parametric correlation provided a relationship assessment between variables for each bank. Results in this paper mostly showed a positive correlation between socio-environmental responsibility (SER) and financial performances, even considering the impacts of Brazilian crisis. The objective of this voluntary disclosure lays on companies’ legitimacy as a dialogue mechanism with society.

Semi-classical Analysis of Spin Systems near Critical Energies

The spectral properties of $su(2)$ Hamiltonians are studied for energies near the critical classical energy $\epsilon_c$ for which the corresponding classical dynamics presents hyperbolic points (HP). A general method leading to an algebraic relation for eigenvalues in the vicinity of $\epsilon_c$ is obtained in the thermodynamic limit, when the semi-classical parameter $n^{-1}=(2s)^{-1}$ goes to zero (where $s$ is the total spin of the system). Two applications of this method are given and compared with numerics. Matrix elements of observables, computed between states with energy near $\epsilon_c$, are also computed and shown to be in agreement with the numerical results.Comment: 3 figure

Resíduo do extrato de própolis em dietas de bovinos com níveis crescentes de proteína sobre a fermentação ruminal

The objective of this work was to evaluate the effect of the residue from the extraction of propolis, added to bovine diets with increasing levels of protein, on ruminal fermentation in vitro. For this, the in vitro gas production technique was used. Incubation was carried out with inocula from three fistulated cows, in three periods. In each period, a cow received a daily dose of 100 g propolis residue. Four diets were evaluated: corn silage (control); and 25, 50, and 75% concentrate based on soybean meal. The following were determined: kinetics of rumen fermentation; dry matter degradation; production of gases, volatile fatty acids (acetate, propionate, and butyrate), methane, and ammonia nitrogen; and pH. The inclusion of 14.4, 15.1, and 9.5% propolis residue, respectively, to 25, 50, and 75% concentrate increased the production of gases from the degradation of fibrous carbohydrates, when compared with the control. The propolis residue reduces methane production and the acetate:propionate ratio at all tested concentrate inclusion levels.O objetivo deste trabalho foi avaliar o efeito do resíduo da extração de própolis, adicionado em dietas de bovinos com níveis crescentes de proteína, sobre a fermentação ruminal in vitro. Para tanto, utilizou-se a técnica de produção de gás in vitro. A incubação foi realizada com inóculos de três vacas fistuladas, em três períodos. Em cada período, uma vaca recebeu uma dose diária de 100 g do resíduo de própolis. Foram avaliadas quatro dietas: silagem de milho (controle); e 25, 50 e 75% de concentrado à base de farelo de soja. Foram determinados: cinética de fermentação ruminal; degradação da matéria seca; produção de gases, ácidos graxos voláteis (acetato, propionato e butirato), metano e nitrogênio amoniacal; e pH. A inclusão de 14,4, 15,1 e 9,5% de resíduo de própolis, respectivamente, a 25, 50 e 75% de concentrado aumentou a produção de gases oriundos da degradação dos carboidratos fibrosos, em comparação ao controle. O resíduo de própolis reduz a produção de metano e a relação acetato:propionato em todos os níveis de inclusão de concentrado testados

Experimental evidence of Alfv\'en wave propagation in a Gallium alloy

Experiments with a liquid metal alloy, galinstan, are reported and show clear evidence of Alfv\'en wave propagation as well as resonance of Alfv\'en modes. Galinstan is liquid at room temperature, and although its electrical conductivity is not as large as that of liquid sodium or NaK, it has still been possible to study Alfv\'en waves, thanks to the use of intense magnetic fi elds, up to 13 teslas. The maximal values of Lundquist number, around 60, are similar to that of the reference experimental study by Jameson [1]. The generation mechanism for Alfv\'en waves and their refl ection is studied carefully. Numerical simulations have been performed and have been able to reproduce the experimental results despite the fact that the simulated magnetic Prandtl number was much larger than that of galinstan. An originality of the present study is that a poloidal disturbance (magnetic and velocity fields) is generated, allowing us to track its propagation from outside the conducting domain, hence without interfering.Comment: 19 pages; Physics of Fluids (2011)

The Effects of \u3cem\u3eTithonia diversifolia\u3c/em\u3e on Dairy Cow Performance

Southeast, South and Central West are the main milk producing regions in the Brazil. Especially in the states of Minas Gerais, Goias and Sao Paulo, the tropical climate is very characteristic, with hot and rainy summers, and dry winters. Dry winters in these states are characterized by scarcity of pasture herbage mass, which directly influence the volume of milk produced. The high volume of milk produced in summer and low volume of milk produced in winter (i.e. seasonality of production which is about 20% of total milk volume) directly affects dairy farmers by reducing its revenue during dry winters due to a drop in milk yield. In addition, it increases the production costs by offering additional roughage supplements to the cattle (sugarcane fresh plus urea, corn silage or sorghum silage), or by feeding more concentrates and/or greater labour costs. Research evaluating the potential of the Tithonia diversifolia in improving milk yield and quality is extremely limited. This research project seeks to develop tools to understand the potential impact on milk composition and cow performance and to evaluate the significance of its outcomes and to aid in the ongoing development of innovative approaches. The aim of this study is to determine the effects of replacing up to 9.1% of sugarcane fresh and up to 6.3% of concentrates (DM basis) with Tithonia diversifolia fresh fed to lactating dairy cows. It is hypothesized that the initial replacement of a portion of the sugarcane fresh and concentrates (corn grain and soybean meal) with the Tithonia diversifolia fresh would not reduce dairy cow performance

Avaliação das silagens de girassol (hibrido m734) obtidas em diferentes épocas de ensilagem pela técnica in vitro semi-automática de produção de gases

Para que o girassol possa ser utilizado com sucesso na forma de silagem, é necessário que se determine o ponto ideal de ensilagem. O objetivo desse experimento foi avaliar através da técnica in vitro semi-automática de produção de gases a cinética de degradação da matéria orgânica (MO) e matéria seca (MS) das silagens do híbrido M734 ensilado com 100, 107, 114 e 121 dias após o plantio. As leituras de pressão dos gases foram feitas através de um transdutor de pressão às 2, 4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48, 72, 96 h pós-inoculação. A cinética ruminal foi descrita matematicamente por meio dos parâmetros: potencial máximo de produção de gases, "lag time", taxa de produção de gases (m) e degradabilidade efetiva da MO e MS para diferentes taxas de passagem (2, 5 e 8%/h) por um modelo unicompartimental. Verificou-se que o corte da cultura em estádios mais tardios levaram a redução no potencial máximo de produção de gases para a MO (162, 155, 144 e 139 mL) e MS (138, 129, 121 e 119 mL); elevação da "lag time" para MO (2,4, 2,5, 2,8 e 2,9 h) e MS (2,5, 2,5, 3,0 e 3,0 h); e diminuição do m para a MO (0,023, 0,022, 0,017 e 0,017 mL/h) e MS (0,022, 0,020, 0,015 e 0,016 mL/h) para as épocas 100, 107, 114 e 121 dias após o plantio, respectivamente. As épocas mais indicadas para a ensilagem do híbrido M734 foram aos 100 e 107 dias após o plantio.The success on sunflower utilization for ensiling is dependent on the correct cutting time during growing season. The objective of this experiment was to evaluate, by using the in vitro gas production technique, "Reading Pressure Technique", the kinetic of organic matter (OM) and dry matter (DM) of silages from the sunflower hybrid M734 obtained at 100, 107, 114 and 121 days after planting. Headspace gas pressure readings were taken at 2, 4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48, 72 and 96 hours post-inoculation. An unicompartimental mathematical model was applied to describe the profiles in terms of the potential gas production, lag phase, rate of gas production and effective dry matter degradation which used 2, 5 and 8%/h rate of passages. It was observed that latter cuttings promoted the reduction on the potential of gas production for OM (162, 155, 144 and 139 mL) and DM (138, 129, 121 and 119 mL); increased of "lag phase" for OM (2,4, 2,5, 2,8 and 2,9 h) and DM (2,46, 2,54, 2,98 and 2,99 h); and reduction of rate fermentation for OM (0,023, 0,022, 0,017 and 0,017 mL/h) and DM (0,022, 0,020, 0,015 and 0,016 mL/h) respectively for 100, 107, 114 and 121 days after planting . The best cutting time for M734 hybrid were at 100 and 107 days after planting