Three-dimensional flow instability in a lid-driven isosceles triangular cavity

Linear three-dimensional modal instability of steady laminar two-dimensional states developing in a lid-driven cavity of isosceles triangular cross-section is investigated theoretically and experimentally for the case in which the equal sides form a rectangular corner. An asymmetric steady two-dimensional motion is driven by the steady motion of one of the equal sides. If the side moves away from the rectangular corner, a stationary three-dimensional instability is found. If the motion is directed towards the corner, the instability is oscillatory. The respective critical Reynolds numbers are identified both theoretically and experimentally. The neutral curves pertinent to the two configurations and the properties of the respective leading eigenmodes are documented and analogies to instabilities in rectangular lid-driven cavities are discussed.

De la prostitution en Europe depuis l'antiquité jusqu'a la fin du XVIIe siècle /

Mode of access: Internet.

De antiqua paroeciarum origine : deque eximia clarissimorum episcoporum in parochos benignitate singularique parochorum in episcopos observantia diatriba /

Mode of access: Internet.

Constructal Design of Energy Systems

This dissertation shows the use of Constructal law to find the relation between the morphing of the system configuration and the improvements in the global performance of the complex flow system. It shows that the better features of both flow and heat transfer architecture can be found and predicted by using the constructal law in energy systems. Chapter 2 shows the effect of flow configuration on the heat transfer performance of a spiral shaped pipe embedded in a cylindrical conducting volume. Several configurations were considered. The optimal spacings between the spiral turns and spire planes exist, such that the volumetric heat transfer rate is maximal. The optimized features of the heat transfer architecture are robust. Chapter 3 shows the heat transfer performance of a helically shaped pipe embedded in a cylindrical conducting volume. It shows that the optimized features of the heat transfer architecture are robust with respect to changes in several physical parameters. Chapter 4 reports analytically the formulas for effective permeability in several configurations of fissured systems, using the closed-form description of tree networks designed to provide flow access. The permeability formulas do not vary much from one tree design to the next, suggesting that similar formulas may apply to naturally fissured porous media with unknown precise details, which occur in natural reservoirs. Chapter 5 illustrates a counterflow heat exchanger consists of two plenums with a core. The results show that the overall flow and thermal resistance are lowest when the core is absent. Overall, the constructal design governs the evolution of flow configuration in nature and energy systems.

Microcrédito emancipatório no nordeste do Brasil? : estudo de caso do Crediamigo Comunidade nos municípios de Caucaia-Ce e Maranguape-Ce

This piece of work consists in a study case of Crediamigo Comunidade, a product from the portfolio of Crediamigo Program of Banco do Nordeste, that uses the methodology of the Comunitary Banks in the concession of low amount loan to poor communities. The main question consists to understand how the Crediamigo Comunidade is characterized faced to the conflict of emancipatory versus liberal paradigms, that exists in the microcredit area. The main objective will analyze how the mechanisms: social capital, empowerment, formation to credit education and better conditions for economic and social issues promoted in the specific objectives of this product, before the dipute between these paradigms. The method adopted analyzed, in a longitudinal perspective, the three years of the product s existence (jun/2005 to jul 2008). Primary and secondary data made possible to identify qualitatively, emancipatory and non emancipatory attributes in the actions and results of Crediamigo Comunidade. It is concluded that the Crediamigo Comunidade works in a liberal logic of the Crediamigo Program, consequently, his focus is not in the emancipation of the poorest clients. The empowerment is individual and not communitary or Freiriano ; the social capital relations enlarges itself in its bounding and bridging ties, but not in its linkage ties, to have access to politic actors and consequently communitary strengthen. All the formation in the Crediamigo is strictly commercial. These characteristics happen by the liberal paradigm in the Crediamigo management and of all of its products, including the Crediamigo Comunidade