435 research outputs found
Capabilities, innovation and entrepreneurship in sub-Saharan Africa
No full textThis paper takes a capability approach to analyze the role of entrepreneurship in the socio-economic development of present-day Sub Saharan Africa. The paper zooms in on the nature of the capabilities that are built through the development of entrepreneurship; the key challenges to the development of such capabilities in a Sub Saharan African context; and the question to what extent successful entrepreneurship in Africa entails the development of a specifically African version of such capabilities. The analysis is based on in-depth case studies of entrepreneurship and capability formation in different African countries, which offer complementary insights. The most successful cases exhibit a highly creative management strategy that is neither completely western, nor solely wedded to African traditions and values. Rather, it revolves around negotiating the interface between these socio-cultural spheres by forging new, creative mixtures in which the strengths of both are combined and conflicts and trade-offs are managed more or less successfully. In the context of the socio-cultural transformation that Africa is currently undergoing in a fast globalizing world, the mastery of this complex art by local entrepreneurs is identified as the most fundamental capability for fostering business success, human development and increased societal wellbeing
Les J.O., fête sportive, enjeu économique. L'impact de la météorologie
No full textAbstract : The Winter Olympic Games, the impact of weather conditions. The author shows hereafter the impact of weather conditions in the organization of the Winter Olympic Games as well, with respect of setting up the Games as for event processes. Requested needs and final system to be run for the occasion are described. As regards of both local and regional economy, the author emphasizes how important is the action of METEO FRANCE. However it is not realy easy to quantify such repercussion.Résumé : Les J.O., fête sportive, enjeu économique. L'impact de la météorologie. L'auteur présente ici l'impact de la météorologie sur l'organisation, la mise en place et le déroulement des J.O., aussi bien en ce qui concerne les 5 années précédant les Jeux que les Jeux eux-mêmes. Il décrit les besoins à satisfaire et le système mis en place à cette occasion. En conclusion, l'auteur tente de montrer l'importance de l'action menée par MÉTÉO FRANCE au regard des retombées économiques, que ce soit au plan local ou régional et même national.Resumen : Juegos Olimpicos, el impacto de la metereologia. El autor presenta el impacto de la metereologia en la organización, la preparación y el desarrollo de los Juegos Olimpicos tanto en los cinco aňos précédentes a los Juegos como durante los Juegos. Describe las necesidades surgidas y los medios utili-zados para satisfacerlas. El autor intenta demostrar la importancia de la acción llevada a cabo por METEO- FRANCE en el terreno económico tanto en el piano local, regional e incluso nacionál.Bellocq André. Les J.O., fête sportive, enjeu économique. L'impact de la météorologie. In: Revue de géographie alpine, tome 79, n°3, 1991. pp. 89-98
Zero-inertia instabilities in rheopectic fluids
No full textThe emergence of fluid instabilities in the relevant limit of vanishing fluid inertia (i.e., arbitrarily close to zero Reynolds number) has been investigated for the well-known Kolmogorov flow. The time-lagged viscosity change from lower to higher values due to shear changes is the crucial ingredient for the instabilities to emerge. This behavior characterizes the so-called rheopectic fluids. The instability does not emerge in shear-thinning or -thickening fluids where viscosity adjustment to local shear occurs instantaneously. No instability arbitrarily close to zero Reynolds number is either observed in thixotropic fluids, even though the viscosity adjustment time to shear is finite like in rheopectic fluids. Numerical tools (through suitable eigenvalue problems from the linear stability analysis) and multiple-scale homogenization techniques are utilized to lead to our conclusions. Our findings may have important consequences in all situations where purely hydrodynamic fluid instabilities or mixing are inhibited due to negligible inertia, such as in microfluidics. To trigger mixing in these situations, suitable (not necessarily viscoelastic) non-Newtonian fluid solutions appear as a valid answer. Our results open interesting questions and challenges in the field of smart (fluid) materials
On isothermal flow of viscous liquids through screw pumps
No full textMechanical, Maritime and Materials Engineerin
Mixing shocks and their influence on the design of liquid-gas ejectors
No full textMechanical, Maritime and Materials Engineerin
Erosion and transport of bed-load sediment
No full textIn this thesis first a general derivation is given of the 'macro'-equations of mass- and linear-momentum balance that govern the mo'mentum transfer from a Newtonian fluid to rigid particles in a fluid-solid mixture. In particular, attention is paid to a) the attenuation of viscous-momentum transfer from the boundary to the interior of a granular bed subject to a surface flow, b) the drag and lift forces exerted by a turbulent shear flow on particles of the bed surface, and, c) the balance of forces acting on a bed load under uniform-flow conditions. It is shown that filter flow driven by shearing along the boundary of a granular sediment bed exerts a drag force on a layer of only two or three particle diameters within the bed. A drag force on the bulk mass of sediment is only exerted by a pore-pressure gradient. Stability conditions are formulated for a loose granular bed subject to erosive flow, at SHIELDS' grain-movement condition and dUring bed-load transport. 'Macro'-stresses acting along 'wavy' surfaces parallel to the bed are defined for that purpose, and an attenuation factor is introduced for the transmission of turbulent fluid shear from the surface towards the interior of the bed. It is shown that SHIELDS' dimensionless expression for the critical bed shear stress at the threshold of continuous sediment motion, 1/Phi , must reach a constant value for low-shear Reynolds' numbers (Re* < O. 5), as long as there is no cohesion between the particles. It is concluded that the bed load, consisting of particles rolling and saltating over the bed, must reduce the maximum turbulent fluid shear at the bed surface, at sufficiently high bed shear stress, to the critical threshold drag that would lead to the initiation of non-ceasing scour.Hydraulic EngineeringCivil Engineering and Geoscience
Aspects of two-phase, gas-liquid, separation related to nuclear steam supply systems
No full textMechanical, Maritime and Materials Engineerin
Social Entrepreneurship in Kenya
No full textThe subject of this research is the promotion of social entrepreneurship in Kenya. There are almost no medium-sized businesses in Kenya which indicates that there is a lack of growth of the many micro and small enterprises. The research investigates what the pitfalls and barriers in culture and in the institutional framework for the country’s entrepreneurship are. Certain cultural dimensions as community feeling, particularism, power distance, and fatalism are discussed, next to some institutional problems as bureaucracy, corruption, and tribal issues. Civil society is examined as an important factor influencing development in a country. It was found to be coming up, but not yet fully developed in Kenya. Recommendations on what would be beneficial changes to promote social entrepreneurship in Kenya are given in terms of cultural transition and institution building. Means to assist these changes are identified in the form of education, gender equality and urbanization. Finally, the theory of the Capability Approach is used as an evaluation tool to indicate the social impact that the proposed transitions in cultural dimensions and developments in entrepreneurship have. This attempt will gain insight and provides a step towards applicability of the theory in practice in relation to cultural values with an emphasis on social entrepreneurship.Management of TechnologyValues and TechnologyTechnology, Policy and Managemen
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