BACKGROUND The optimal particle size of a beta 2 agonist or anticholinergic aerosol in patients with severe airflow obstruction is unknown. METHODS Seven stable patients with a mean forced expiratory volume in one second (FEV1) of 37.9% of the predicted value inhaled three types of monodisperse salbutamol and ipratropium bromide aerosols with particle sizes of 1.5 microns, 2.8 microns, and 5 ...

It is well known that metallic particles reduce the reliability of Gas-Insulated Substation (GIS) equipments by initiating partial discharge (PDs) that can lead to breakdown and complete failure of GIS. This paper investigates the characteristics of PDs caused by metallic particle adhering to the solid spacer. The PD detection and measurement were carried out by using IEC 60270 method with part...

We report laboratory determinations of the shear resistance to sliding melting ice with entrained particles over a hard, impermeable surface. With higher particle concentrations and larger particle sizes, Coulomb friction at particlebed contacts dominates and the shear stress increases linearly with normal load. We term this the sandy regime. When either particle concentration or particle size ...

The currently used composite resin classification systems need review if they are to continue to serve as descriptives and quantitative parameters denoting the filler particle content of these materials. Examination of the particles in 12 composite resins using a technique of washing the filler particles from the matrix of the composite resin was presented as yet another method of grouping comp...

Phosphate-induced immobilization is recognized as one of effective in situ remediation methods for heavy metal contaminated soils. Phosphate-based minerals that adsorb, chelate, or complex heavy metals in soil were greatly concerned as effective heavy metals immobilizing materials. Effects of particle sizes of rock phosphate on immobilizing heavy metals in Pb-Zn mine soils by a greenhouse exper...

In order to study in depth the differences basic characteristics between iron ore fines commonly used by a steel company, and guide sintering performance plant choose best allocation method, experimental studies on of seven powders three sizes were carried out using micro-sintering equipment, mainly including assimilation properties, liquid phase fluidity, bonding strength. The results research...