Numerical Investigation On Detonation Cell Evolution In A Channel With Area-Changing Cross Section

The two-dimensional cellular detonation propagating in a channel with area-changing cross section was numerically simulated with the dispersion-controlled dissipative scheme and a detailed chemical reaction model. Effects of the flow expansion and compression on the cellular detonation cell were investigated to illustrate the mechanism of the transverse wave development and the cellular detonation cell evolution. By examining gas composition variations behind the leading shock, the chemical reaction rate, the reaction zone length, and thermodynamic parameters, two kinds of the abnormal detonation waves were identified. To explore their development mechanism, chemical reactions, reflected shocks and rarefaction waves were discussed, which interact with each other and affect the cellular detonation in different ways.

The changing behaviour of the term structure of post-war US

Using U.S. interest rate data covering the period 1950:1-1992:7, this paper tests the rational expectations model of the term structure of interest rates. We show evidence that the rational expectations model of the term structure is supported by the data during the seventies and a period lasting from the mid-eighties to the end of the sample. However, during the …fties, sixties and a period that covers most of the Volcker’s office term (from September 1979 to April 1986) the term structure model is rejected by the data. Moreover, wefind evidence of regime changes in the short-term rate process and the term structure of interest rates. These regime switches roughly coincide with changes in the Federal Reserve chairman. The switches in monetary policy taking place when the chairmanship of the Federal Reserve changes therefore seem to play an important role in characterizing the term structure of interest rates.

Encouraging them to come to us: changing the way that information is made available to farmers

Recommendations for changes to service provision and fisheries policy in support of poverty alleviation emerged recently in India from a process know as facilitated advocacy (see Case Study SI 2) that helped to negotiate and support a role for poor people and their service providers, to contribute to changes in services and policies. Two of the key recommendations to emerge from farmers and fishers, which were prioritized by Fisheries Departments, were to change the way that information is made available and to simplify procedures for accessing government schemes and bank loans. This case which identifies the origin of these recommendations to change the way that information is made available, shows how different models of the concept have emerged, and follows the development of the One-stop Aqua Shops (OAS) in the eastern Indian states of Jharkhand, Orissa and West Bengal, that represent a new and vital tier in communications in aquaculture. (12 p.)