Environmental Constraints, Commodity Mix, And Research Resource Allocation
The purpose of this paper is to show how the allocation of research resources among commodities and the effects of such allocations on the output mix depend upon (a) the initial production conditions, (b) the nature of the research production functions, (c) the nature of the demand relations for the commodity outputs, (d) relative factor endowments, and (e) the existence of different types of environmental constraints. The basic model used is a two-factor, two-product model in which certain types of technical change are introduced.
Market Integration: A Study of Sorghum Prices in Western India
This article examines the popular view in underdeveloped countries that there exist large regional price differences that are caused by speculative elements in trade. The data bearing on the prices of sorghum in a number of primary and terminal markets in India suggest that these differences are not caused by the activities of the traders. The analysis emphasizes the high degree of interdependence between wholesale markets in the process of price formation. Regional price differences often result from differences in varieties of the grain traded. Prices for the same product may differ because of transport costs. Price discrepancies of the order larger than transport costs may result from such factors as transport bottlenecks and government control on the movement of goods.
Ozonation of polycyclic aromatic hydrocarbons in oil/water-emulsions: mass transfer and reaction kinetics.
The ozonation of highly condensed polycyclic aromatic hydrocarbons (PAH) was studied in oil/water-emulsions, which are comparable to poorly water-soluble PAH in industrial wastewaters and at contaminated sites. As there was a lack of knowledge about the ozonation in oil/water-emulsions, first the ozone mass transfer was studied and optimized from the gas to the water phase and from the water to the oil phase. The ratio of mass transfer and oxidation reaction was determined by the Hatta-number and revealed a slow, quasi homogeneous reaction of ozone with PAH inside the oil droplets. Because the ozone gas concentration had no influence under the optimized conditions, the selective PAH-ozonation could be described microkinetically by a direct ozone reaction of pseudo-first order regarding PAH-concentrations. The determined PAH mean reaction rate constants of 1.02 min(-1) in oil/water-emulsions are in the upper range as found for PAH dissolved in water. These results give a new insight into the ozonation in the three-phase systems and into the treatment of highly condensed, hardly biodegradable PAH.