The nature and impacts of fines in smelter-grade alumina

Fines in smelter-grade aluminas art recognized (is a significant process problem in aluminum smelting. However understanding the nature of this fine material and how it impacts the reduction process arc, less clearly understood The combination of new analytical methods such as variable pressure scanning electron microscopy and very; high field solid state nuclear magnetic resonance provide new insights into the phases present and their spatial distribution within aluminas, and suggest how such fine materials are generated, particularly during calcination in the alumina refinery

Regional inequalities in mortality

STUDY OBJECTIVE--To examine the hypothesis of sustained and persistent inequalities in health between British regions and to ask how far they are a consequence of using standardised mortality ratios as the tool of measurement. DESIGN, SETTING AND PARTICIPANTS--Data are regional, age specific death rates at seven points in time from 1931 to 1987-89 for the British regions, reconstructed to make them comparable with the 1981 regional definitions. Log variance is used to measure inequality; regional rankings are also used. MEASUREMENTS AND MAIN RESULTS--There has been a substantial convergence in age specific death rates between regions in younger but not in older age groups. In younger age groups the historic north/south gradient has disappeared; it persists in older groups. CONCLUSIONS--Use of standardised mortality ratios obscures differences in the convergence rates of age specific death rates between regions. Simple conclusions about the persistence of a north/south divide are not justified. Different processes of change seem to be at work in different age groups