Unsteady Flow Of A Viscous Incompressible Fluid Between Parallel Plates

In the present paper an exact solution of the Navier Stokes equations has been obtained, considering the flow of a viscous incompressible fluid between two infinitely extended parallel plates when upper plate is moving with uniform velocity and the lower plate is performing linear oscillations in its own plane. The technique of Laplace transform has been employed to obtain the velocity distribution, which has been shown graphically

The uncertain benefits of environmental reform in open economies

We compare the instantaneous and the long run effects of environmental reform in closed and open economies. Harmonization upward (decreasing distortions where they are most severe) or harmonization downward (increasing distortions where they are less severe), both tend to increase instantaneous world welfare. Environmental reform in a country with less severe distortions works against harmonization and may decrease welfare. Harmonization upward has more beneficial long-run effects than harmonization downward, and also provides higher expected instantaneous benefits if the current stock is uncertain. In the short run there is a conflict between environmental protection and reduction of unemployment, but in the long run the two goals are consistent

Steady creeping motion of a liquid bubble in an immiscible viscous fluid bounded by a vertical porous cylinder of finite thickness

The creeping vertical motion of a fluid sphere (drop or gas) or liquid bubbles of different shapes in another immiscible fluid confined by porous boundaries is encountered in several situations in industry and technology. Such flows are generally multi-phase in nature. In this work, we have considered a flow field comprising a non-Newtonian bubble region surrounded by a liquid film of Newtonian fluid. This inner region is bounded by a permeable cylindrical medium pervaded by the same Newtonian fluid. We have studied the interaction features of this multiphase flow in terms of certain practically important geometrical and physical parameters. We have carried out an exact analysis of the governing equations in the three flow fields-Non-Newtonian, Newtonian film and porous regions. The effects of pressure gradient, permeability and rheological parameters on the bubble velocity and the flow in different regions have been discussed

Limited Cooperation in International Environmental Agreements

Governments' desire to ameliorate environmental problems may conflict with other goals. Policy levels which balance different objectives can be altered by policy changes in other countries. A decrease in the importance of the pollution problem, or an increase in its global extent, increase the likelihood that tighter environmental regulations in one region induce laxer policies elsewhere. The transboundary character and the importance of environmental externalities also affect the amount of cooperation needed to improve members' welfare in a coalition. More global pollution problems require a larger coalition. However, the critical coalition size may be larger or smaller for more severe problems

Dynamics and Limited Cooperation In International Environmental Agreements

The amount of cooperation needed to improve the welfare of signatories of International Environmental Agreements (IEAs), in the presence of market imperfections, depends on the characteristics of pollution. In a dynamic model, the conventional wisdom on the effect of free-riding needs to be modified for certain types of pollution problems. For local pollution problems, a sufficient level of free-riding actually promotes signatories' welfare. For global pollution problems, the conventional wisdom is correct insofar as free-riding makes it more difficult to form a successful IEA. However, for some global pollution problems, free-riding may disappear. A static model may overstate or understate the difficulty of forming a successful IEA. The effect of an IEA is sensitive to differences between the duration of the IEA and agents' planning horizon

Common ground between free-traders and environmentalists

We use a North–South model with property right differences and resource dynamics to study the effects of trade on resource use and welfare. Autarky is likely to Pareto-dominate free trade in the long run when the environment is quite fragile, and the result is reversed when the environment is quite resilient. Trade may cause an environmentally poor country to “drag down” its richer trading partner, when they degrade their stocks which would be preserved under autarky. It may enable the environmentally richer country to “pull up” its partner, when they preserve their stocks which would be degraded under autarky