A method of comparing the kinetics of isothermal solid-state reactions based on the classical equation for analysis of nucleation-and-growth processes is described. In this method, plots of In In (1-a) vs In (time), where 01 is the fraction reacted, are used to distinguish reaction mechanisms. Even nonintegral slopes obtained for values of the fraction reacted from 0.15 to 0.50 may indicate whether the reaction rate is diffusion-or phase-boundary-controlled. The problems of ascertaining zero time and self-cooling (or heating) of the reacting sample can be observed in the analysis but do not cause severe difficulties in interpretation, as they can for analyses based on reduced-time plots. The analysis is applied to the dehydroxylation of kaolinite and of brucite and the decomposition of BaCO,,.

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This paper simulates the macroeconomic effects of the AIDS epidemic in Malawi. This is done by using Bulatao's (1990) predictions of the disease's demographic impact in a dual-economy macro model. The with-AIDS scenario is compared with a counterfactual no-AIDS scenario to assess the impact of the disease if it spreads unchecked. The results suggest that by the year 2010, Malawian real GDP could be as much as 10% smaller than it would have been in the absence of the AIDS epidemic. The impact on per capita income is smaller, ranging from 0% to 3% lower than it would have been in the no-AIDS case by 2010.

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