Analysis of the linear oscillation dynamics of Fluidyne engines.

A Fluidyne engine is a liquid piston Stirling engine that uses thermally induced self-sustained oscillations of water and air that are filled in a looped tube and tuning column. It presents high potential for use as a low-temperature-difference Stirling engine with a simple structure. This study analyzes the linear oscillation dynamics of the Fluidyne from a thermoacoustic point of view, with particular emphasis on the local specific acoustic impedance of the working gas, which is given by the ratio of the complex amplitudes of the pressure and velocity oscillations in the regenerator of the Fluidyne.

Rising incidence of oral cancer in Ahmedabad city.

Context: In 1999, an increase in mouth cancer incidence among young men (< 50 years) in urban Ahmedabad was reported to be occurring along with decreasing mouth cancer incidence in older age groups and increasing oral submucous fibrosis incidence associated with areca nut consumption among young men in Gujarat. The aim was to investigate whether the increase in the incidence mouth cancer that had started among young men in the 1990 s was continuing.

Settings And Design: Ahmedabad urban population, comparison of reported mouth cancer cases in the population across four time period.

Medical problems among dental patients at the school of dentistry, the university of the West Indies.

This study ascertained demographic information and prevalence rates of medical problems among 571 new and consecutive dental patients attending the emergency clinic of the School of Dentistry, The University of the West Indies. Patients were interviewed by specially trained and calibrated dental students and interns. Various medical problems of patients were recorded in individual open-ended case sheets, maintaining their privacy and confidentiality.