The presence of airborne pollutants in indoor environments has been associated with occupants' discomfort and/or adverse health effects. This study investigates occupational exposure in relation to indoor air mixing and source location relative to a human body. Experimental and computational methods were used to provide information about the pollutant distribution in the vicinity of the human b...

Efficient mixing at the microscale remains a formidable engineering challenge. Recent advancement and proliferation of Lab-on-a-Chip (LOC) and Micro Total Analysis Systems (μTAS) has demanded accelerated development and demonstration of novel micromixers as successful mixing is critical to device performance. Passive techniques such as chaotic advection and shear thinning as well as active meth...

In acidified aluminium (Al) rich freshwater positively charged Al-species (Al(i)) are the key toxic components due to the accumulation in fish gills. As a countermeasure, liming is used to increase the pH and reduce the concentration of Al(i)-species; in particular low molecular mass (LMM) Al(i)-species by hydrolyses. However, very toxic high molecular mass (HMM) Al polymers can form in the uns...

In aquifers subject to saline water intrusion, the mixing zone between freshwater and saltwater displays strong physico-chemical gradients. Although the microbial component of these specific environments has been largely disregarded, the contribution of micro-organisms to biogeochemical reactions impacting water geochemistry has previously been conjectured. The objective of this study was to ch...

Context. Recent solar photospheric abundance analyses have led to a significant reduction of the metal abundances compared to the previous determinations. (Z/X)S is 30% smaller, down to 0.0165. The solar models computed with standard opacities and diffusion processes using these new abundances give poor agreement with helioseismic inversions for the sound-speed profile, the surface helium abund...

Transport and mixing zone of desert dust and sulphate over Tropical Africa and the Atlantic Ocean region K. V. Desboeufs and G. Cautenet LISA, UMR 7583, Universités Paris 7 et 12, Créteil, France LaMP, UMR 6026, Université Clermont 2, Aubière, France Received: 5 November 2004 – Accepted: 24 February 2005 – Published: 1 August 2005 Correspondence to: K. V. Desboeufs ([email protected]....

Convective mixing of dissolved carbon dioxide (CO2) with formation brine has been shown to be a significant factor for the rate of dissolution of CO2 and thus for determining the viability of geological CO2 storage sites. In most previous convection investigations, a no-flow boundary condition was used to represent the interface between an upper region with CO2 and brine and the single-phase br...

Current layered accretion models neglect the properties of the “dead zone”. However, as argued here from simple considerations, the thickness of this zone is a critical quantity when the disc is in hydrostatic equilibrium. It controls not only the structure of the superficial, active layers, but also the mid-plane density and the total disc mass, and should therefore be introduced in models of ...