The goal of this work is to examine in detail how turbulence evolves in the presence of both vertical stratification and horizontal (straining) buoyancy fluxes. Horizontal density gradients are a ubiquitous feature of estuarine and coastal flows, as are sheared velocity profiles. The combination of these two features produces a buoyancy flux which can be either stabilizing or destabilizing, dep...

The effects of partial slip on stagnation-point flow and heat transfer due to a stretching vertical sheet is investigated. Using a similarity transformation, the governing partial differential equations are reduced into a system of nonlinear ordinary differential equations. The resulting equations are solved numerically using a shooting method. The effect of slip and buoyancy parameters on the ...

The longstanding problem of modeling double-mode behaviour of classical pulsators was solved with the incorporation of turbulent convection into pulsation hydrocodes. However, the reasons for the computed double-mode behaviour were never clearly identified. In our recent papers (Smolec & Moskalik 2008a,b) we showed that the double-mode behaviour results from the neglect of negative buoyancy eff...

In contrast to conventional expectations based on the stability of steady shear flows, elementary time-periodic stratified flows that are unstable at arbitrarily large Richardson numbers are presented here. The fundamental instability is a parametric one with twice the period of the basic state. This instability spontaneously generates local shears on buoyancy time scales near a specific angle ...

A general solution for the slope of a fusion curve is presented. It is not the Clausius-Clapeyron equation which is a special case for one-component systems. The connection between fusion curve slope and crystal/liquid buoyancy is obscure in multicomponent systems even though the slopes of fusion curves for any given composition are always well defined. The olivine flotation hypothesis at high ...

In this paper we present a method of buoyancy-driven centripetal pumping utilizing a heavy, waterimmiscible liquid to displace an aqueous sample radially inwards against the prevailing centrifugal force. Using formerly introduced dissolvable-film valving, we demonstrate metering and bidirectional periodical pumping of a single sample in the radial direction. We then show integrated sample discr...

We have studied the extent to which buoyancy e€ects in horizontal pipe ̄ows of drag-reducing viscoelastic ̄uids cause distortions to both laminar and turbulent temperature pro®les. In the case of laminar ̄ows, these distortions may lead to variations in Nusselt numbers that are larger than those seen for Newtonian pipe ̄ows under similar conditions. In the case of turbulent drag-reducing ̄ows, ...

In the present work, a gastroretentive in situ gelling liquid formulation for controlled delivery of ranitidine was formulated using sodium alginate (low, medium and high viscosity grades), calcium carbonate (source of cations) and ranitidine. Prepared formulations were evaluated for viscosity, buoyancy lag time and buoyancy duration, drug content and in vitro drug release. Formulation variable...

A mechanism of buoyancy regulation in cyanobacteria was investigated in a fluctuating light environment typical of the mixed layer in a lake. New measurements of density and cellular carbohydrate content were obtained from a field sample of the cyanobacterium Microcystis aeruginosa. The rate of increase in carbohydrate and density in this cyanobacterium does not instantaneously adjust to an inc...

In this study the commercial flow code STAR-CD has been used to simulate a laboratory experiment involving a so-called fire whirl. Such phenomena are typically characterized as exhibiting significantly enhanced mixing and consequently higher combustion rates due to an interaction of buoyancy and vorticity, but the details of this are only beginning to be understood. The present study focuses at...