The turbulent heat flux in low Mach number flows with large density variations

A transport equation has been derived which is the difference between the volume- and mass-averaged velocities and is simply related to the turbulent heat flux phi sup h. Using this equation and an assumption analogous to the drift flux approximation of two-phase flow modeling, an algebraic closure relation for phi sup h that exibits fluxes due to directed transport proportional to -del anti p and due to gradient transport proportional to -del tau has been obtained

The Problem of Quaker Identity

The paper constitutes a summary of my attempts, during the past 15 years, to understand contemporary Quakers and Quakerism. The issue on which I focus is the difficulty in representing Quaker identity given the heterogeneity of Quaker belief. During the last decade I have found three approaches useful in analysing this problem. In the first place, I found that Quaker identity is revealed through their talk in and around Meeting. Although each individual friend has a unique biographical trajectory, this talk tends to be both storied and thematic. Furthermore, such narrative discourse is coloured by one particularly pervasive character of canonic Quakerism: the plain. Quakers have always preferred the plain to the embellished or ornamented-both in their theology, their speech and in their material culture. I extend my earlier work on plaining here by reference to the work of Webb Keane and Bruno Latour. Third, and finally, I describe how the work of Pierre Bourdieu and especially his work on habitus and practice theory has contributed to the way in which I understand the enduring character of the Quaker Meeting