Propiedades higroscópicas y de estabilidad dimensional de madera de alcornoque (Quercus suber L.)

Cork oak (Quercus suber L.) wood has a potential for high value uses because of its strength and aesthetic properties but one obstacle is the lack of knowledge of the wood-water relations. Variations in wood equilibrium moisture content, density and dimensions were studied at air temperatures of 22°C and 27°C (representing acclimatized homes and summer non-acclimatized homes, respectively) varying from 80% to 30% of relative humidity. For indoor uses (22-27°C, 50-65% of relative humidity), the wood equilibrium moisture content ranged 12-17% and these values are recommended for the final commercial drying of cork oak wood. The fibre saturation point averaged 27%. Total volumetric shrinkage at 22°C-27°C averaged 12%, the linear shrinkage 8.1-8.5% and 3.6-3.6%, respectively in tangential and radial directions. Anisotropy averaged 2.3. Wood density at 12% moisture content ranged 0.63 to 0.67 g/cm3. The higroscopicity obtained was 0.003. The average tangential differential shrinkage was 0.32 for both temperatures and the average radial differential shrinkage was 0.14 and 0.15, at 22°C and 27°C respectively. The shrinkage factor was 0.90 cm3/g and 0.82 cm3/g, at 22°C and 27°C respectively. Differences between temperatures were only statistically significant at 80-70% of relative humidity.La madera de alcornoque tiene potencial para usos de alto valor debido a su resistencia y propiedades estéticas, pero presenta un obstáculo como es la falta de conocimiento de las relaciones agua-madera. Se han estudiado las variaciones en el contenido de humedad de equilibrio de la madera, la densidad y las dimensiones a temperaturas del aire de 22°C y 27°C (que representa casas climatizadas y casas de verano no aclimatadas, respectivamente) variando entre 80% a 30% de humedad relativa. Para usos interiores (22-27° C, 50-65% de humedad relativa), el equilibrio de humedad de la madera osciló entre el 12-17% y se recomiendan estos valores para el secado final de la madera comercial de alcornoque. El punto de saturación de la fibra promedio es del 27%. La contracción volumétrica total a 22°C-27°C en promedio es de un 12%, la contracción lineal varía entre 8.1-8.5% y 3.6-3.6%, respectivamente en direcciones tangenciales y radiales. La anisotropía promedio fue de 2,3. La densidad de la madera con un contenido de humedad del 12% varió entre 0,63 a 0,67 g/cm3. La higroscopicidad obtenida fue de 0,003. La contracción diferencial tangencial promedio fue de 0,32 para ambas temperaturas y la contracción radial diferencial promedio fue de 0,14 y 0,15, a 22°C y 27°C respectivamente. El factor de contracción fue de 0,90 cm3/g y 0,82 cm3/g, a 22°C y 27°C respectivamente. Las diferencias entre las temperaturas fueron estadísticamente significativas sólo al 80-70% de humedad relativa

Invariants from classical field theory

We introduce a method that generates invariant functions from perturbative classical field theories depending on external parameters. Applying our methods to several field theories such as abelian BF, Chern-Simons and 2-dimensional Yang-Mills theory, we obtain, respectively, the linking number for embedded submanifolds in compact varieties, the Gauss' and the second Milnor's invariant for links in S^3, and invariants under area-preserving diffeomorphisms for configurations of immersed planar curves.Comment: 20 pages, 1 figure, to appear in J. Math. Phy

Diagnóstico e tratamento da mastite.

bitstream/item/60508/1/IT110001.pd

Superpulsed low-level laser therapy protects skeletal muscle of mdx mice against damage, inflammation and morphological changes delaying dystrophy progression.

Aim: To evaluate the effects of preventive treatment with low-level laser therapy (LLLT) on progression of dystrophy in mdx mice. Methods: Ten animals were randomly divided into 2 experimental groups treated with superpulsed LLLT (904 nm, 15 mW, 700 Hz, 1 J) or placebo-LLLT at one point overlying the tibialis anterior muscle (bilaterally) 5 times per week for 14 weeks (from 6th to 20th week of age). Morphological changes, creatine kinase (CK) activity and mRNA gene expression were assessed in animals at 20th week of age. Results: Animals treated with LLLT showed very few morphological changes in skeletal muscle, with less atrophy and fibrosis than animals treated with placebo-LLLT. CK was significantly lower (p = 0.0203) in animals treated with LLLT (864.70 U.l−1, SEM 226.10) than placebo (1708.00 U.l−1, SEM 184.60). mRNA gene expression of inflammatory markers was significantly decreased by treatment with LLLT (p<0.05): TNF-α (placebo-control = 0.51 µg/µl [SEM 0.12], - LLLT = 0.048 µg/µl [SEM 0.01]), IL-1β (placebo-control = 2.292 µg/µl [SEM 0.74], - LLLT = 0.12 µg/µl [SEM 0.03]), IL-6 (placebo-control = 3.946 µg/µl [SEM 0.98], - LLLT = 0.854 µg/µl [SEM 0.33]), IL-10 (placebo-control = 1.116 µg/µl [SEM 0.22], - LLLT = 0.352 µg/µl [SEM 0.15]), and COX-2 (placebo-control = 4.984 µg/µl [SEM 1.18], LLLT = 1.470 µg/µl [SEM 0.73]). Conclusion: Irradiation of superpulsed LLLT on successive days five times per week for 14 weeks decreased morphological changes, skeletal muscle damage and inflammation in mdx mice. This indicates that LLLT has potential to decrease progression of Duchenne muscular dystrophy

Otimização da concentração de misturas de herbicidas considerando a resistência de plantas daninhas.

I CMAC Sudeste

L’argomentazione delle decisioni della Cassazione: tra autorevolezza del precedente ed esigenze di semplificazione.

La relazione mira ad approfondire il ruolo dell'argomentazione nel ragionamento dei giudici della Corte di Cassazione italiana e processo decisionale, indicando la funzione del vincolo dello stare decisis (precedente) in un sistema di civil law, quale quello italiano, e tenendo conto del carico di ricorsi che ogni anno la Corte deve gestire

AC conductivity of graphene: from tight-binding model to 2+1-dimensional quantum electrodynamics

We consider the relationship between the tight-binding Hamiltonian of the two-dimensional honeycomb lattice of carbon atoms with nearest neighbor hopping only and the 2+1 dimensional Hamiltonian of quantum electrodynamics which follows in the continuum limit. We pay particular attention to the symmetries of the free Dirac fermions including spatial inversion, time reversal, charge conjugation and chirality. We illustrate the power of such a mapping by considering the effect of the possible symmetry breaking which corresponds to the creation of a finite Dirac mass, on various optical properties. In particular, we consider the diagonal AC conductivity with emphasis on how the finite Dirac mass might manifest itself in experiment. The optical sum rules for the diagonal and Hall conductivities are discussed.Comment: 46 pages, ws-ijmpb, 7 EPS figures; final version published in IJMP