While partial energy transitions have been observed in the past, the complete transition of a fossil-based energy system to a sustainable energy one is historically unprecedented on a large scale. Switching from an economy based on energy stocks to one based on energy flows requires a social paradigm shift. This paper defines Sustainable Energy Transition (SET) and introduces a set of five prop...

Many of the observational evidences for black hole rely on the fact that the incoming gas has the potential to become as hot as its virial temperature Tvirial ∼ 10 13 K (Rees, 1984). This flow is usually cooled down through bremsstrahlung and Comptonization effects and hard and soft states are produced depending on the degree by which this cooling takes place (Chakrabarti & Titarchuk, 1995). Th...

Marine renewable energy is emerging as one of the fast-growing industry in the last decades, as modern society pushes for technologies that can convert energy contained from winds, waves, tides and stream flows. The implementation of renewable energy technologies impose high demands on both structural and environmental engineering, as the energy converters have to work under extreme conditions ...

Mexico City lies in a high altitude basin where air quality and pollutant fate is strongly influenced by local winds. The combination of high terrain with weak synoptic forcing leads to weak and variable winds with complex circulation patterns. A gap wind entering the basin in the afternoon leads to very different wind convergence lines over the city depending on the meteorological conditions. ...

Around the world, governments are making huge investments in environmental flows. However, much of the rationale for these releases is based on expert opinion and is thus open to challenge. Empirical studies that relate ecological responses to flow restoration are mostly case studies of limited generality. Radically, different approaches are required to inform the development of general models ...

open-channel junctions have a broad application in civil and environmental engineering. formation of a low-pressure zone with recirculating flow (high sedimentation) accompanied by a high-velocity zone (high erosion) is the most characteristic feature of flow in junctions. a large number of researches have been performed to study the complexity of the flow in junctions in open-channel flows. in...

Design of a natural dry cooling tower has been accomplished in two sections: the design of heat exchangers and the numerical solution of flow through the tower. Heat exchanger (Heller type) has been simulated thermodynamically and then coupled with a computer program, which calculated the turbulent natural convection flow through the tower. The computer program developed for this purpose can be...

We investigate magnetized solar-like stellar winds by means of self-consistent threedimensional (3D) magnetohydrodynamics (MHD) numerical simulations. We analyze winds with different magnetic field intensities and densities as to explore the dependence on the plasma-β parameter. By solving the fully ideal 3D MHD equations, we show that the plasma-β parameter is the crucial parameter in the conf...

Many astrophysical flows occur in inhomogeneous media. The broad-line regions (BLR) of active galactic nuclei (AGNs) are one of the important examples where emission-line clouds interact with the outflow. We present results of a numerical study of the interaction of a steady, planar shock / supersonic postshock flow with a system of embedded cylindrical clouds in a two-dimensional geometry. Det...