Probing the two-scale-factor universality hypothesis by exact rotation symmetry-breaking mechanism

We probe the two-scale factor universality hypothesis by evaluating, firstly explicitly and analytically at the one-loop order, the loop quantum corrections to the amplitude ratios for O($N$) $\lambda\phi^{4}$ scalar field theories with rotation symmetry-breaking in three distinct and independent methods in which the rotation symmetry-breaking mechanism is treated exactly. We show that the rotation symmetry-breaking amplitude ratios turn out to be identical in the three methods and equal to their respective rotation symmetry-breaking ones, although the amplitudes themselves, in general, depend on the method employed and on the rotation symmetry-breaking parameter. At the end, we show that all these results can be generalized, through an inductive process based on a general theorem emerging from the exact calculation, to any loop level and physically interpreted based on symmetry ideas.Comment: 17 pages, 3 figure

Caracterização e correlação de propriedades mecânicas e constituintes químicos de doze variedades de abacaxis (gênero ananas).

Fibras de folhas de abacaxis de doze variedades diferentes foram ensaiadas sob tração e caracterizadas com relação à sua composição química: teores de extrativos, lignina, holocelulose, celulose e hemicelulose. As frações de extrativos variaram para as amostras estudadas entre 4 e 9%, a lignina total variou de 23 a 52%, celulose de 66 a 76%, hemicelulose de 7 a 16%, e holocelulose de 77 a 88%. As frações de celulose foram superiores em relação a outras espécies de fibras, indicando possibilidade de obtenção de nanofibras. As fibras estudadas obtiveram valores de módulo elástico variando entre 37 a 86GPa e a resistência à tração entre 629 a 1309MPa; caracterizando todas as variedades de fibras estudadas aptas para utilização como reforço mecânico em compósitos poliméricos. Observou-se correlação diretamente proporcional entre o módulo elástico e o teor de celulose. A projeção do valor de módu!o elástico para uma fibra com teor de 100% de celulose ficou igual ao citado na literatura (nanocristal de celulose), habilitando as fibras de abacaxis para produção de nanofibras para utilização em nanocompósitos

Diversidade genética de bactérias isoladas de nódulos de feijão-caupi cultivado em solos sob diferentes sistemas em Juazeiro, BA.

O objetivo deste trabalho foi determinar a diversidade genética de bactérias isoladas de nódulos de feijão-caupi (Vigna unguiculata L. Walp.) em solos sob diferentes sistemas de cultivo desta leguminosa por meio do uso da técnica de IGS-RFLP

Numerical simulation of the flexural behaviour of composite glass-GFRP beams using smeared crack models

This paper presents a numerical study about the flexural behaviour of rectangular composite glass-GFRP beams, comprising annealed glass and GFRP pultruded profiles bonded with two different adhesives: (soft) polyurethane and (stiff) epoxy. The main objectives of this study were: (i) to fully characterize the non-linear behaviour of glass using the smeared crack approach; and (ii) to assess the applicability of different options to simulate adhesively bonded glass-GFRP joints. An extensive parametric study was developed to evaluate the influence of five parameters on the glass post-cracking non-linear behaviour: (i) glass fracture energy, Gf, (ii) crack band width, h, (iii) glass tensile strength, fg,t, (iv) shape of the tension-softening diagram, and (v) shear retention factor, β. The wide range of the joints’ shear stiffness was simulated by either (i) assuming a perfect bond between glass and GFRP (i.e., neglecting the presence of the adhesive), or (ii) explicitly considering the adhesive, by means of using (ii.1) plane stress elements, or (ii.2) interface elements. For the beams analysed in this paper, the following material model for glass provided a good agreement with experimental results: Gf in the range of 3 to 300 N/m, h equal to the square root of the finite element area, fg,t = 50 MPa, linear softening diagram and β according to a power law. It was also shown that the hypothesis of perfect bond at the GFRP-glass interfaces allows for an accurate simulation of joints with high levels of interaction (epoxy), while calibrated interface elements are needed for joints with low level of interaction (polyurethane).The authors wish to acknowledge FCT, ICIST/CERIS and ISISE for funding the research, and companies SIKA, Guardian and ALTO for supplying the adhesives, the glass panes and the GFRP pultruded profiles used in the experiments. The first author also wishes to thank FCT for the financial support through his PhD scholarship SFRH/BD/80234/2011

Effect of gamma irradiation on carotenoids and vitamin C contents of Papaya fruit (Carica papaya L.) cv. Golden.

The irradiation has been considered an alternative process for decay control extending shelf life of fresh fruits. This study was conducted to investigate the effect of gamma irradiation on functional constituents on papaya fruits cv. Golden. Fruits were harvested into maturation 1 degree (stage) and irradiated with 0.8 kGy (Cobalt 60 source-MSD Nordion irradiator), and then stored at 24 ± 2 ° C. Total carotenoids and vitamin C contents were evaluated in the pulp fruits, in the 5, 7 e 9 th days post-harvest by a reversed-phase and ion exclusion column by a high performance liquid chromatography. Results demonstrated that the irradiation induced alterations in the total carotenoids and vitamin C levels. However, these changes did not affect the adequacy of vitamins A and C (for adult and children) in relation to daily nutritional requirements. In conclusion, the present data provide evidence that the irradiated papaya, did not impair reduce these nutritional characteristics