Probabilistic sensitivity analysis to understand the influence of micromechanical properties of wood on its macroscopic response

This paper investigates the influence of the uncertainty in different micromechanical properties on the variability of the macroscopic response of cross-laminated timber plates, by means of a probabilistic sensitivity analysis. Cross-laminated timber plates can be modelled using a multiscale finite element approach which although suitable, suffers from high computational cost. Investigating parametric importance can incur considerable time penalty since conventional sensitivity analysis relies on a large number of code evaluations to produce accurate results. In order to address this issue, we build a statistical approximation to the code output and use it to perform sensitivity analysis. We investigate the effect of a collection of parameters on the density and Young’s moduli of wood. Additionally, the influence on the response of cross-laminated timber plates subject to bending, in-plane shear and compression loads is investigated due to its relevance within the engineering community. The presented results provide a practical insight into the importance of each micromechanical parameter, which allows research effort to be focused on important wood properties

Vacuna antirrábica Fuenzalida-Palacios administrada intradérmicamente :estudio experimental en conejos

Con el objeto de estudiar la vía intradérmica para inmunización antirrabica, utilizando vacuna fuenzalida-palacios, se realizó un estudio comparativo de los títulos de anticuerpos neutralizantes en 4 grupos de conejos. El grupo A recibió dosis diarias de 1 ml de vacuna vía subcutánea durante un período de 14 días más 2 refuerzos de igual cantidad a los 10 y 20 días después de suministrada la última dosis de la serie inicial. El grupo B recibió una dosis de 0.2 ml por vía intradérmica. El grupo C fue inoculado con 5 dosis de 0.2 ml por vía intradérmica cada 48 horas, más 2 refuerzos a los 10 y 20 días después de la última dosis de la serie. Al grupo D se le inoculó con 3 dosis de 0.2 ml por vía intradérmica cada 96 horas, más 2 refuerzos de igual cantidad a los 30 y 60 días después de la última dosis de la serie principal. Los grupos A, C y D presentaron respuesta de anticuerpos y el resultado fue negativo para el grupo B. Se concluye que: si se utiliza la vía intradérmica para inmunización, se obtiene una respuesta similar en el título de anticuerpos con una cantidad mínima de vacuna, con relación a la respuesta de la inoculación por vía subcutánea, no existe diferencia en los niveles de gamma globulina circulante entre el grupo que recibio mayor estímulo antigénico y aquel que fue inoculado con una dosis mínima de antígeno, la vía intradérmica es una excelente ruta de inmunización que responde con mínimas dosis a la protección. No se presenta reacción local en el sitio de la inoculaciónCunicultura-Conejo (oryctolagus) - Oryctolagus Cuniculo

Cómo lograr longevidad con calidad de vida. Caso sector lácteos 2000-2009

En la primera década del siglo XXI, las empresas colombianas se han visto afectadas por discontinuidades de tipo tecnológico, político, demográfi co, económico que han puesto a prueba su capacidad de aprendizaje para ajustarse a dichas difi cultades y poder sobrevivir. Estas discontinuidades presentes en el entorno han generado una turbulencia en el sector de lácteos; fenómeno caracterizado por tres elementos: incertidumbre, dinamismo y complejidad. La incertidumbre se hace evidente al momento de tomar decisiones, sin lograr tener certeza sobre lo que puede pasarle a la empresa o sobre el efec to de una decisión que se tome; el dinamismo se logra observar por el cam bio per manente en las necesidades de los clientes y el surgimiento de nuevos productos, que origina incremento de la rivalidad por precio; y la complejidad puede identifi carse en el surgimiento de otros actores con los que se debe interactuar para llevar a cabo una transacción

Lepra - Algunos aspectos Inmunológicos -

252 patients with Leprosy were studied. 108 males and 44 females with Lepromatous Leprosy, 48 males and 52 females with Tuberculoid Leprosy. The following studies were performed in their sera: electrophoretic pattern, quantification of circulating levels of C3. IgG, IgA and IgM. No specific electrophoretic pattern was seen. only the gamma fraction was elevated and this alteration was statiscally significative in Lepromatous Leprosy. IgG and IgM levels were elevated in Lepromatous Leprosy, this alteration is statistically significative. IgA appears slightly elevated in both typesof Leprosy. No alteration in the level of circulating C3 was seen.Se estudiaron 252 pacientes con Lepra: 156 hombres y 96 mujeres. 108 hombres y 48 mujeres con Lepra Lepromatosa; 48 hombres y 52 mujeres con Lepra Tuberculoide. En esta muestra se estudiaron su patrón electroforético. la concentración de C3 y los niveles circulantes de IgG, IgA e IgM. Se  encontró que no existe un patrón definido electroforético que pueda asociarse con la Lepra, solo la fracción gamma muestra niveles altos en Lepra Lepromatosa y esta alteración comparada con la población general tiene significancia estadística. Unicamente la IgG e IgM muestran aumentos considerables con significación estadística para Lepra Lepromatosa. IgA se encuentra aumentada en los dos tipos de Lepra. No se encontró ninguna alteración en los niveles circulantes de C3

Position Control of a Quadrotor under External Constant Disturbance

International audienceIn the present work, an adaptive backstepping algorithm is developed in order to counteract the effects of disturbances. These disturbances are modeled as a constant force in the translational model part and as a constant torque in the orientation model part. We make the deduction of the mathematical expression for the proposed control algorithm and also we show its performance in simulation. Additionally, we include some experiments for validating the results obtained via simulation

Negative Thermal Expansion Near the Precipice of Structural Stability in Open Perovskites

Negative thermal expansion (NTE) describes the anomalous propensity of materials to shrink when heated. Since its discovery, the NTE effect has been found in a wide variety of materials with an array of magnetic, electronic and structural properties. In some cases, the NTE originates from phase competition arising from the electronic or magnetic degrees of freedom but we here focus on a particular class of NTE which originates from intrinsic dynamical origins related to the lattice degrees of freedom, a property we term structural negative thermal expansion (SNTE). Here we review some select cases of NTE which strictly arise from anharmonic phonon dynamics, with a focus on open perovskite lattices. We find that NTE is often present close in proximity to competing structural phases, with structural phase transition lines terminating near T=0 K yielding the most prominent displays of the SNTE effect. We further provide a theoretical model to make precise the proposed relationship among the signature behavior of SNTE, the proximity of these systems to structural quantum phase transitions and the effects of phase fluctuations near these unique regions of the structural phase diagram. The effects of compositional disorder on NTE and structural phase stability in perovskites are discussed

The Host Galaxy and Optical Light Curve of the Gamma-Ray Burst GRB 980703

We present deep HST/STIS and ground-based photometry of the host galaxy of the gamma-ray burst GRB 980703 taken 17, 551, 710, and 716 days after the burst. We find that the host is a blue, slightly over-luminous galaxy with V_gal = 23.00 +/- 0.10, (V-R)_gal = 0.43 +/- 0.13, and a centre that is approximately 0.2 mag bluer than the outer regions of the galaxy. The galaxy has a star-formation rate of 8-13 M_sun/yr, assuming no extinction in the host. We find that the galaxy is best fit by a Sersic R^(1/n) profile with n ~= 1.0 and a half-light radius of 0.13 arcsec (= 0.72/h_100 proper kpc). This corresponds to an exponential disk with a scale radius of 0.22 arcsec (= 1.21/h_100 proper kpc). Subtracting a fit with elliptical isophotes leaves large residuals, which suggests that the host galaxy has a somewhat irregular morphology, but we are unable to connect the location of GRB 980703 with any special features in the host. The host galaxy appears to be a typical example of a compact star forming galaxy similar to those found in the Hubble Deep Field North. The R-band light curve of the optical afterglow associated with this gamma-ray burst is consistent with a single power-law decay having a slope of alpha = -1.37 +/- 0.14. Due to the bright underlying host galaxy the late time properties of the light-curve are very poorly constrained. The decay of the optical light curve is consistent with a contribution from an underlying Type Ic supernova like SN1998bw, or a dust echo, but such contributions cannot be securely established.Comment: 9 pages, 5 figures, LaTeX using A&A Document Class v4.05, to appear in A&

The Minimum-Uncertainty Squeezed States for for Atoms and Photons in a Cavity

We describe a six-parameter family of the minimum-uncertainty squeezed states for the harmonic oscillator in nonrelativistic quantum mechanics. They are derived by the action of corresponding maximal kinematical invariance group on the standard ground state solution. We show that the product of the variances attains the required minimum value 1/4 only at the instances that one variance is a minimum and the other is a maximum, when the squeezing of one of the variances occurs. The generalized coherent states are explicitly constructed and their Wigner function is studied. The overlap coefficients between the squeezed, or generalized harmonic, and the Fock states are explicitly evaluated in terms of hypergeometric functions. The corresponding photons statistics are discussed and some applications to quantum optics, cavity quantum electrodynamics, and superfocusing in channeling scattering are mentioned. Explicit solutions of the Heisenberg equations for radiation field operators with squeezing are found.Comment: 27 pages, no figures, 174 references J. Phys. B: At. Mol. Opt. Phys., Special Issue celebrating the 20th anniversary of quantum state engineering (R. Blatt, A. Lvovsky, and G. Milburn, Guest Editors), May 201