86 research outputs found
Polarization stabilization in vertical-cavity surface-emitting lasers through asymmetric current injection
We present experimental evidence that asymmetric current injection in intracavity contacted vertical-cavity surface-emitting lasers (VCSELs) stabilizes the polarization of the emitted light. Anisotropies in the gain and loss mechanisms introduced by asymmetric current injection are considered to explain this effect. The design scheme opens perspectives to obtain actual polarization control in VCSEL
Thermodynamic Field Theory with the Iso-Entropic Formalism
A new formulation of the thermodynamic field theory (TFT) is presented. In
this new version, one of the basic restriction in the old theory, namely a
closed-form solution for the thermodynamic field strength, has been removed. In
addition, the general covariance principle is replaced by Prigogine's
thermodynamic covariance principle (TCP). The introduction of TCP required the
application of an appropriate mathematical formalism, which has been referred
to as the iso-entropic formalism. The validity of the Glansdorff-Prigogine
Universal Criterion of Evolution, via geometrical arguments, is proven. A new
set of thermodynamic field equations, able to determine the nonlinear
corrections to the linear ("Onsager") transport coefficients, is also derived.
The geometry of the thermodynamic space is non-Riemannian tending to be
Riemannian for hight values of the entropy production. In this limit, we obtain
again the same thermodynamic field equations found by the old theory.
Applications of the theory, such as transport in magnetically confined plasmas,
materials submitted to temperature and electric potential gradients or to
unimolecular triangular chemical reactions can be found at references cited
herein.Comment: 35 page
Studies on the influence of host plants and effect of chemical stimulants on the feeding behavior in the muga silkworm, Antheraea assamensis
The feeding habits of Antheraea assamensis, Helfer (Lepidoptera: Saturniidae) larvae towards the
leaves of its four different host plants, Persea bombycina King ex. Hook (Laurales: Lauraceae),
Litsea polhantha Jussieu, L. salicifolia Roxburgh ex. Nees and L. citrata Blume, and the
chemical basis of feeding preference were investigated. Nutritional superiority of young and
medium leaves with respect to soluble protein, total phenol and phenylalanine ammonia lyase
activity was observed in the leaves of P. bombycina compared to other host plants. Attraction and
feeding tests with detached leaves and artificial diet with different chemical stimulants revealed
that a mixture of the flavonoids, myrcetin, and 7, 2’, 4’ trimethoxy dihydroxy flavone with sterol
compound β-sitosterol elicited the most biting behavior by A. assamensis larvae. While linalyl
acetate alone attracted larvae towards the leaves of the host plants, a mixture of caryophyllene,
decyl aldehyde and dodecyl aldehyde was found to both attract them to the host leaves and cause
biting behavior. Azaindole was found to deter them from the host plants
Erratum du numéro 6 (juin)
Erratum de l'article "Nouveau système d'unités en électromagnétisme" par J.-E. Verschaffelt, J. Phys. Radium, t. 3, n°6, p. 225-228 (juin 1932)
Sur les propriétés des fluides à l'état de saturation au voisinage du point critique
Pas de Résumé disponibl
Nouveau système d'unités en électromagnétisme
L'auteur propose de choisir conventionnellement l'unité de charge électrique, prise comme nouvelle unité fondamentale, et égale à 1 : 10^4 du Faraday,charge portée par un ion gramme d'hydrogène. On aurait ainsi cinq unités fondamentales, et une constante diélectrique du vide K différente de l'unité
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