Homotopy type of gauge groups of quaternionic line bundles over spheres

Let P be a principal S(3)-bundle over a sphere S(n), with n >= 4. Let G(p) be the gauge group of P. The homotopy type of G(p) when n - 4 was studied by A. Kono in [A. Kono, A note on the homotopy type of certain gauge groups, Proc. Roy. Soc. Edinburgh Sect. A 117 (1991) 295-297]. In this paper we extend his result anti we study the homotopy type of the gauge group of these bundles for all n <= 25. (C) 2008 Elsevier B.V. All rights reserved.

UNIT VECTOR FIELDS ON ANTIPODALLY PUNCTURED SPHERES: BIG INDEX, BIG VOLUME

We establish in this paper a lower bound for the volume of a unit vector field (v) over right arrow defined ou S(n) \ {+/-x}, n = 2,3. This lower bound is related to the sum of the absolute values of the indices of (v) over right arrow at x and -x.

Separate spheres and public policy : the role of women in the development of children's services in Victorian local government, 1840-1992

The thesis is an explanation of the development of pre-school children's services (infant welfare, kindergartens and child care) at local government level in Victoria. The critical framework of analysis focuses on three dimensions of public policy: 1) the socio-historical environment; 2) the political processes involved in the development of the specific children's service; and 3) the major individuals and groups that exerted pressure for children's service, The argument is threefold. Firstly it is argued that the political environment of children's services has been dominated by the practice of separate spheres of public and private, in which the care of children is primarily the role of women. Secondly, it is argued that the political processes surrounding the development of local children's services have involved all levels of government in what is termed a local state. Thirdly, it is argued that the development of these children's services in local government has resulted mainly from the work of women both individually and collectively. Since the three services of infant welfare, kindergartens and child care all became a normal function of children's services at different times, the circumstances that surrounded each development exhibited different aspects of the three major arguments. The periodisation is broken into four phases: 1) the establishment of local government with no children's services in the nineteenth century; 2) the establishment of infant welfare services in local government in the early part of the twentieth century; 3) the incorporation of kindergartens into local government after the second world war; and 4) the incorporation of child care into local government in the 1970s and 1980s. The thesis concludes by arguing that the existence of children's services in local government in Victoria is testimony to the remarkable work of those women who have pursued the issue both individually and collectively. It has been the identification of children's services as a women's issue in Australian politics that has enabled women's groups at different times to influence the policy makers in diverse ways. However, while the establishment of children's services as a legitimate political concern brings the matter onto the public agenda, the separate spheres still remains a contested issue in the public policies of children's services.

Forces measured between latex spheres in aqueous electrolyte : Non-DLVO behavior and sensitivity to dissolved gas

An atomic force microscope was used to measure the forces acting between two polystyrene latex spheres in aqueous media. The results show an electrostatic repulsion at large separations which is overtaken by an attractive “hook” that pulls the two spheres into contact from a considerable range (20−400 nm), much larger than could be expected for a van der Waals attraction. The range of operation of this attraction varies from one experiment to another and is not correlated with electrolyte concentration. However, the range is found to decrease significantly when the level of dissolved gas in the water is reduced.

Scholar who excelled in several spheres

Obituary for Robin Grove ( 2 Feb. 1941 – 25 Dec. 2012 )

Tax filing choices for the household under separable spheres bargaining

If household choices can be rationalized by the maximization of a well defined utility function, allowing spouses to file individually or jointly is equivalent to offering the envelope of the two tax schedules. If, instead, household ’preferences’ are constantly being redefined through bargaining, the option to file separately may affect outcomes even if it is never chosen. We use Lundberg and Pollak’s (1993) separate spheres bargaining model to assess the impact of filing options on the outcomes of primary and secondary earners. Threat points of the household’s bargain are given for each spouse by the utility that he or she attains as a follower of a counter-factual off-equilibrium Stackelberg game played by the couple. For a benchmark tax system which treats a couple’s average taxable income as if it were that of a single individual, we prove that if choices are not at kinks, allowing couples to choose whether to file jointly or individually usually benefits the secondary earner. In our numeric exercises this is also the case when choices are at kinks as well. These findings are, however, quite sensitive to the details of the tax system, as made evident by the examination of an alternative tax system.

Finite group actions on products of spheres

In this work we make some contributions to the theory of actions of finite groups on products of spheres. Suppose that the group Z(q)(tau) acts freely on the product of k copies of spheres. Question: Is r less than or equal to k? We solve this question for several values of r and k.

Effects of self-assembly process of latex spheres on the final topology of macroporous silica

This paper surveys the topology of macroporous silica prepared using latex templates covering the submicrometric range (0.1-0.7 mu m). The behavior of latex spheres in aqueous dispersion has been analyzed by dynamic light scattering (DLS) measurement indicating the most appropriate conditions to form well-defined cubic arrays. The optical behavior of latex spheres has been analyzed by transmittance and reflectance measurements in order to determine their diameter and filling factor when they were assembled in bidimensional arrays. Macroscopic templates have been obtained by a centrifugation process and their crystalline ordering has been confirmed by porosimetry and scanning electron microscopy. These self-assembled structures have been used to produce macroporous silica, whose final topology depends on the pore size distribution of the original template. It has been seen that latex spheres are ordered in a predominant fcc arrangement with slipping of tetragonal pores due to the action of attractive electrostatic interactions. The main effect is to change the spherical shape of voids in macroporous silica into a hexagonal configuration with possible applications to fabricate photonic devices with novel optical properties. (c) 2005 Elsevier B.V. All rights reserved.

Selección de documentos y publicaciones de la CEPAL relacionados con la incorporación de la perspectiva de género en las principales áreas del desarrollo de América Latina y el Caribe = Selected ECLAC documents and publications relating to mainstreaming the gender perspective in the main spheres of the regional development process in Latin America and the Caribbean

Publicación bilingüe

Cooperación técnica internacional en el marco de la actual crisis latinoamericana: posibles campos de acción = International technical co-operation and the current crisis in Latin America: possible spheres of action

Incluye Bibliografía

Electromagnetic energy within coated spheres containing dispersive metamaterials

An exact expression is derived for the time-averaged electromagnetic energy within a magneto-dielectric coated sphere, which is irradiated by a plane and time-harmonic electromagnetic wave. Both the spherical shell and core are considered to be dispersive and lossy, with a realistic dispersion relation of an isotropic split-ring resonator metamaterial. We obtain analytical expressions for the stored electromagnetic energies inside the core and the shell separately and calculate their contributions to the total average energy density. The stored electromagnetic energy is calculated for two situations involving a metamaterial coated sphere: a dielectric shell and dispersive metamaterial core, and vice versa. An explicit relation between the stored energy and the optical absorption efficiency is also obtained. We show that the stored electromagnetic energy is an observable sensitive to field interferences responsible for the Fano effect. This result, together with the fact that the Fano effect is more likely to occur in metamaterials with negative refraction, suggest that our findings may be explored in applications.