Surface and bulk polaritons in a linear magnetoelectric multiferroic with canted spins: Transverse Electric polarisation

Some magnetoelectric multiferroics have a canted spin structure that can be described by a Dzyaloshinkii-Moriya coupling. We calculate properties and features expected for surface and bulk magnon polaritons in such media with a linear magnetoelectric interaction for the case of transverse electric polarisation. The dielectric polarisation and magnetisation of weak ferromagnetism are constrained to lie in the plane parallel to the surface. We examine a geometry with the polarisation oriented in the film plane and present numerical results for the transverse electric polarisation. Particular attention is given to non-reciprocal surface modes, which exist in frequency between two bulk bands, and show how these modes can be modified by external magnetic field. Results for attenuated total reflection are presented, and discussed in relation to nonreciprocity. Example results are calculated for the canted antiferromagnet BaMnF4.Comment: 14 pages, 6 figure

Introdução e produção de fruteiras de clima temperado em regiões tropicais.

A região nordeste, mediante a participação dos seus polos irrigados, é a principal região produtora e exportadora de frutas tropicais frescas do Brasil. A região possui mais de 300.000 ha irrigados localizados nos diversos estados e norte de Minas Gerais, cultivando, principalmente, mangueiras, videiras, bananeiras, cajueiros, citros, coqueiros, goiabeiras, aceroleiras, meloeiros, melancieiras, dentre outras

Nonlinear Spin Dynamics in Ferromagnets with Electron-Nuclear Coupling

Nonlinear spin motion in ferromagnets is considered with nonlinearity due to three factors: (i) the sample is prepared in a strongly nonequilibrium state, so that evolution equations cannot be linearized as would be admissible for spin motion not too far from equilibrium, (ii) the system considered consists of interacting electron and nuclear spins coupled with each other via hyperfine forces, and (iii) the sample is inserted into a coil of a resonant electric circuit producing a resonator feedback field. Due to these nonlinearities, coherent motion of spins can develop, resulting in their ultrafast relaxation. A complete analysis of mechanisms triggering such a coherent motion is presented. This type of ultrafast coherent relaxation can be used for studying intrinsic properties of magnetic materials.Comment: 1 file, LaTex, 23 page

Anthropometric characteristics of male rink hockey goalkeeper's according to their competitive level

Objective: Evaluate the anthropometric characteristics of male rink hockey goalkeepers, and to compare the variation according to their competitive level (international vs. non-international). Methods: Body mass, stature, sitting height, arm span, waist and hip circumferences and four skinfold measurements (triceps, medial calf, subscapular and supraspinale) of international (n = 12) and non-international (n = 23) goalkeepers were taken. Body mass index (BMI, weight/height 2), the sum of four skinfolds, the sitting height/stature ratio, waist/hip ratio and the relative arm span were also calculated. Results: International rink hockey goalkeepers have lower values of subcutaneous adiposity for the sum of the four skinfolds (P = 0.042; d = 0.76) particularly in the triceps (P = 0.016; d = 0.87) and are taller than non-international goalkeepers (+3.8 cm [2.2%]; 180.5 ± 7.0 vs. 176.6 ± 4.8 cm; t = 1.920; P = 0.064; d = 0.65). Conclusion: The findings could indicate that stature and body fat may have important implications for scouts regarding the selection process and coaches that work with players on developing performance. Future research should investigate the extent to which different anthropometric measures influence performance in rink hockey goalkeepers

Design of a new test chamber for evaluation of the toxicity of rubber infill

A test chamber was projected and built (according to ISO 16000-9 Standard) to simulate atmospheric conditions experienced by rubber infill (when applied in synthetic turf pitches) and measure accurately the airborne emissions of pollutants such as dusts and volatile organic compounds (VOC), as well as pollutants present in leachates. It should be pointed out that standard ISO 16000-9 is only concerned with the determination of the emission of VOC from building products and furnishing (not specific of synthetic turf materials), whereas other standards are concerned with the emission of leachates only. This procedure is to be considered as a technical option to the lysimeter "global turf system evaluation" when the rubber infill alone is to be evaluated. The advantage of the proposed option considering this "test chamber" is its simplicity and economy. This test chamber is actually installed and being used for tests in LAIST

Comparação de modelos regressão aleatória para descrição das herdabilidades associadas à curva de crescimento de ovinos Santa Inês.

Resumo - Funções polinomiais da idade de diferentes ordens foram avaliadas na modelagem dos efeitos aleatórios para estimação de herdabilidades associadas à curva de crescimento de ovinos Santa Inês. Os efeitos fixos incluídos nos modelos de análise foram grupo de contemporâneo, a idade da ovelha ao parto e os polinômios de Legendre da idade de ordem quatro para representar a curva média de crescimento. Na parte aleatória, consideraram-se funções de diferentes ordens para modelar as variâncias associadas aos efeitos genéticos aditivos direto e materno e aos efeitos de ambiente permanente de animal e da mãe. A variância residual foi ajustada por meio de um polinômio ordinário da idade de ordem seis. De acordo com o valor do critério AIC e o teste da razão de verossimilhança, uma função contínua com as ordens cinco, cinco, sete e três, respectivamente, para os efeitos genéticos aditivos direto e materno e o ambiente permanente de animal e da mãe (k=5573), foi suficiente para ajustar a variância nos dados. Porém, de acordo com o BIC, o modelo com as ordens três, três, cinco e três, para os mesmos efeitos citados anteriormente (k=3353), proporcionou melhor ajuste nas variâncias, conseqüentemente nas herdabilidades estimadas. As herdabilidades estimadas indicam que a seleção para peso resultará em pequenos ganhos genéticos. [Comparison of random regression models for the description of the heritability associated with the growth curve of Santa Ines sheep]. Abstract - Polynomial functions of age from different orders were evaluated on the modeling of random effects associated with the growth curve of Santa Ines sheep. The fixed effects included in the analysis were contemporary groups, the age of dam at lambing and the Legendre polynomial of age of order four to represent the average growth curve. On the random part, functions of different orders were considered for modeling the variances associated with direct and maternal additive genetic effects and with direct and maternal permanent environmental effects. The residual variance was fitted by an ordinary polynomial of age of order six. According to the value of the criteria AIC and the likelihood ratio test, a continual function with the orders five, five, seven and three, respectively, for the direct and maternal additive genetic effects and direct and maternal permanent environmental effects (k=5573) was enough for fitting the variance on data. However, according to the value of the criterion BIC, the model with the orders three, three, five and three (k=3353), for the same effects above, provided best fit in the variances, consequently in the heritability estimated. The estimated heritabilities indicate that the selection for weight will result in small genetic gain

MARTA: A high-energy cosmic-ray detector concept with high-accuracy muon measurement

A new concept for the direct measurement of muons in air showers is presented. The concept is based on resistive plate chambers (RPCs), which can directly measure muons with very good space and time resolution. The muon detector is shielded by placing it under another detector able to absorb and measure the electromagnetic component of the showers such as a water-Cherenkov detector, commonly used in air shower arrays. The combination of the two detectors in a single, compact detector unit provides a unique measurement that opens rich possibilities in the study of air showers.Comment: 11 page