Compressible laminar boundary-layer flows of a dusty gas over a semi-infinite flat-plate

The compressible laminar boundary-layer flows of a dilute gas-particle mixture over a semi-infinite flat plate are investigated analytically. The governing equations are presented in a general form where more reasonable relations for the two-phase interaction and the gas viscosity are included. The detailed flow structures of the gas and particle phases are given in three distinct regions : the large-slip region near the leading edge, the moderate-slip region and the small-slip region far downstream. The asymptotic solutions for the two limiting regions are obtained by using a seriesexpansion method. The finite-difference solutions along the whole length of the plate are obtained by using implicit four-point and six-point schemes. The results from these two methods are compared and very good agreement is achieved. The characteristic quantities of the boundary layer are calculated and the effects on the flow produced by the particles are discussed. It is found that in the case of laminar boundary-layer flows, the skin friction and wall heat-transfer are higher and the displacement thickness is lower than in the pure-gas case alone. The results indicate that the Stokes-interaction relation is reasonable qualitatively but not correct quantitatively and a relevant non-Stokes relation of the interaction between the two phases should be specified when the particle Reynolds number is higher than unity.

Flow pattern in chandler loop - the artificial thrombus formation

In this paper a hydrodynamic approach is used to analyse carefully the flow field inChandler loop--the artificial thrombus formation. The results obtained show that near thelower meniscus where the thrombus is formed, there is a back flow accompanied with asecondary flow and its mainflow is toward the meniscus, thus providing a favourable condi-tion for corpuscle aggregation. Our finding is valuable for studying the mechanism ofthrombus formation in artificial organ and in vivo.

Endogenous Unions Formation

This paper analyzes the process of endogenous union formation in the context of a sequential bargaining model between a firm and several unions and tries to explain why workers may be represented by several unions of different sizes. We show that the equilibrium number of unions and their relative size depend on workers' attitudes toward the risk of unemployment and union configuration is independent of labor productivity.

Union Formation and Bargaining Rules in the Labor Market

This paper analyzes union formation in a model of bargaining between a firm and several unions. We address two questions: first, the optimal configuration of unions (their number and size) and, second, the impact of the bargaining pattern (simultaneous or sequential). For workers, grouping into several unions works as a price discrimination device which, at the same time, decreases their market power. The analysis shows that optimal union configuration depends on the rules that regulate the bargaining process (monopoly union, Nash bargaining or right to manage).