The symmetries of the Dirac--Pauli equation in two and three dimensions

We calculate all symmetries of the Dirac-Pauli equation in two-dimensional and three-dimensional Euclidean space. Further, we use our results for an investigation of the issue of zero mode degeneracy. We construct explicitly a class of multiple zero modes with their gauge potentials.Comment: 22 pages, Latex. Final version as published in JMP. Contains an additional subsection (4.2) with the explicit construction of multiple zero mode

Conservation laws in Skyrme-type models

The zero curvature representation of Zakharov and Shabat has been generalized recently to higher dimensions and has been used to construct non-linear field theories which either are integrable or contain integrable submodels. The Skyrme model, for instance, contains an integrable subsector with infinitely many conserved currents, and the simplest Skyrmion with baryon number one belongs to this subsector. Here we use a related method, based on the geometry of target space, to construct a whole class of theories which are either integrable or contain integrable subsectors (where integrability means the existence of infinitely many conservation laws). These models have three-dimensional target space, like the Skyrme model, and their infinitely many conserved currents turn out to be Noether currents of the volume-preserving diffeomorphisms on target space. Specifically for the Skyrme model, we find both a weak and a strong integrability condition, where the conserved currents form a subset of the algebra of volume-preserving diffeomorphisms in both cases, but this subset is a subalgebra only for the weak integrable submodel.Comment: Latex file, 22 pages. Two (insignificant) errors in Eqs. 104-106 correcte

Generalized Eikonal Knots and New Integrable Dynamical Systems

A new class of non-linear O(3) models is introduced. It is shown that these systems lead to integrable submodels if an additional integrability condition (so called the generalized eikonal equation) is imposed. In the case of particular members of the family of the models the exact solutions describing toroidal solitons with a non-trivial value of the Hopf index are obtained. Moreover, the generalized eikonal equation is analyzed in detail. Topological solutions describing torus knots are presented. Multi-knot configurations are found as well.Comment: 13 page

Use of Alternative Wood for the Ageing of Brandy de Jerez

The use of alternative types of wood has arisen for the aging of the Brandy de Jerez, on a pilot plant level. In particular, besides the use of American oak, two more types of oak have been studied, French oak and Spanish oak, allowed by the Technical File for the ID Brandy de Jerez, and chestnut, which, though it is not officially allowed, is a type of wood which had been traditionally used in the area for the aging of wines and distillates. All of them have been studied with different toasting levels: Intense toasting and medium toasting. The study of the total phenolic composition (TPI), chromatic characteristics, organic acids, and sensory analysis have proven that chestnut leads to distillates with a higher amount of phenolic compounds and coloring intensity than oak. This behavior is the opposite as regards the toasting of the wood. Among the different types of oak, Spanish oak produces aged distillates with a higher phenolic composition and a higher color intensity. Regarding tasting, the best-assessed samples were those aged with chestnut, French oak, and American oak, and the assessors preferred those who had used a medium toasting level to those with an intense leve

Calidad de vida, salud y ejercicio físico : una aproximación al tema desde una perspectiva psicosocial

El propósito del presente artículo es ofrecer algunas de las relaciones que se han establecido entre la Actividad Física y la Calidad de Vida. Asimismo, se pretende exponer algunas de las aportaciones surgidas de las investigaciones en este ámbito científico. En la última década, la Psicología del Deporte ha ampliado su ámbito de actuación, pasando a ocuparse entre otras cuestiones de la relación existente entre la Actividad Física y los posibles beneficios para los practicantes. Estos beneficios quedan reflejados en aspectos tanto físicos, como psicológicos y sociales.The aim of this paper consists of offering some ot the relationships that have been established between physical activity and quality of life. Furthermore, we attempt to show some of the suggestions appearing in researches related to this scientific field. In the last decade, Sport Psychology has widened it

Características de lanas blanqueadas en la industria.

Se ha procedido a la determinación de las características de lanas que han sido blanqueadas con peróxido de hidrógeno en industrias de diferentes países. Los parámetros de las lanas blanqueadas son comparados con los de las no blanqueadas y algunos de aquéllos son relacionados entre sí. Se proponen dos índices que se consideran de utilidad para definir la calidad del blanqueo en función de la mejora de la blancura y de la variación de la solubilidad en álcali y del contenido de ácido cisteico, respectivamente.Peer Reviewe

A Theoretical Framework for Modeling Asymmetric, Nonpositive Definite and Nonuniform Distance Functions on Rn

In this paper, we give theoretical foundations for modeling distance functions on the usual Euclidean space Rn, wheredistance may refer to physical kilometers, liters of fuel consumed, time spent in traveling, or transportation cost. In ourapproach, a distance function d is derived from a function F0 called the fundamental function of d. Our distancefunctions, unlike metrics, can be asymmetric and non-positive definite, and unlike the Lp norms, they can be nonuniform.We illustrate our theoretical framework by modeling an asymmetric and non-uniform distance function on R2which can take negative values

Posibilidades del blanqueo de la lana por vaporizado a temperaturas superiores a los 100°C en presencia de peróxido de hidrógeno.

Se estudia, a través de un plan central rotacional de experiencias, el blanqueo oxidante y reductor de la lana con peróxido de hidrógeno, en medios alcalino y ácido, y bisulfito sódico a temperaturas superiores a 100°C. La relación entre las variables del proceso y las propiedades de la lana blanqueada se ha estudiado haciendo uso de las regresiones múltiples. Las ecuaciones de regresión se ajustan francamente bien a los resultados experimentales. El blanqueo de la lana en medio alcalino por el proceso de impregnación-vaporizado proporciona siempre un blanco mejor que cuando se trabaja en medio ácido. En el blanqueo alcalino, el vaporizado a temperaturas superiores a 100-120°C conduce a una disminución del efecto de blanqueo y a una superior alteración de la fibra. El blanqueo con bisulfito sódico por vaporizado a temperaturas superiores a 100°C no mejora el blanco ni reduce el tiempo del proceso en relación con el blanqueo a 100°C.Through a rotationnel central design of experiments, oxidizing and reducing bleaching of wool with hydrogen peroxide is studied, in both alkaline and acidic media, as well as with sodium bisulphite at temperatures above 100°C. The relation between the variables of the process and the properties of bleached wool has been also studied by means of multiple regressions. Regression equations fit quite well with the experimental results. Wool bleaching in an alkaline medium by the pad-steam process yields always a better whiteness than in un acidic medium. In an alkaline medium, steaming at temperatures above 100-120°C decreases the bleaching effect and leads to a higher alteration of the fibre. Bleaching with sodium bisulphite at temperatures higher than 100°C does neither improve nor reduce the process time as compared to bleaching at 100°C.Moyennant un plan central de rotation, on étudie le blanchiment oxydant et réducteur de la laine avec péroxyde d'hydrogène, en milieux alcalin et acide, et bisulfite de sodium à températures supérieures à 100°C. On a étudié le rapport entre les variables du processus et les propriétés de la laine blanchie en se servant des regressions multiples. Les équations de regression s'ajustent franchement bien aux résultats expérimentaux. La blanchiment de la laine en milieu alcalin par le procédé de foulardage-vaporisage fournit toujours un blanc meilleur que lorsqu'on travaille en milieu acide. Dans le blanchiment alcalin, le vaporisage à températures supérieures à 100-120°C conduit à une diminution de l'effet de blanchiment et à une altération supérieure de la fibre. Le blanchiment avec bisulfite de sodium par vaporisage à températures supérieures à 100°C n'amiliore pus le blanc ni réduit le temps du processus en rapport avec le blanchiment à 100°C.Peer Reviewe

A BPS Skyrme model and baryons at large Nc

Within the class of field theories with the field contents of the Skyrme model, one submodel can be found which consists of the square of the baryon current and a potential term only. For this submodel, a Bogomolny bound exists and the static soliton solutions saturate this bound. Further, already on the classical level, this BPS Skyrme model reproduces some features of the liquid drop model of nuclei. Here, we investigate the model in more detail and, besides, we perform the rigid rotor quantization of the simplest Skyrmion (the nucleon). In addition, we discuss indications that the viability of the model as a low energy effective field theory for QCD is further improved in the limit of a large number of colors N_c.Comment: latex, 23 pages, 1 figure, a numerical error in section 3.2 corrected; matches published versio