RESUMO
The formaldehyde-sulfite reaction is an example of an "acid-to-alkali" clock. It displays an induction period, during which the pH varies only slowly in time, followed by a reaction event, during which the pH increases rapidly by several units. When the reaction is performed in a closed (batch) reactor, the clock time is found to increase with a decrease in initial concentrations of formaldehyde and sulfite and an increase in the total initial concentration of S(IV). At long times, following the clock event, there is a slow decrease in pH. In an open (flow) reactor, bistability between a low-pH steady state (pH approximately 6-8) and a high-pH steady state (pH approximately 11) is observed. Additionally, we report the existence of sustained, small-amplitude oscillations in pH in this system. An extended kinetic mechanism reproduces the batch behavior but fails to account for the complex behavior observed in the flow reactor. Possible additional reaction steps are discussed.
RESUMO
The method of calculating district psychiatric manpower described by Watson was applied to seven geriatric psychiatry services in Scotland serving a population of 1,445,000 including 209,600 individuals over the age of 65 years of age. The overall medical staffing of these services was only 63.6% of the estimated requirement and when individual consultants were considered only 62% of the necessary time was available. If it is assumed that half of the extra medical time should be provided by consultants, then 3.2 consultant WTEs will be needed for geriatric psychiatry for a population of 200,000 with 30,000 elderly people. If there was no change in the proportion of medical work provided by consultants, the figure would be 2.9 consultant WTEs per 30,000 population aged over 65 years. Extra supporting staff are also required to meet the requirements of the Watson formula.