BACKGROUND Albuterol hydrofluoroalkane (HFA) either alone or with a valved holding chamber is used to treat bronchoconstriction. Delays between actuation and inhalation are common. Currently, the recommended interval between actuations of an albuterol HFA is 60 s. Using a shorter interval when multiple actuations are ordered will improve productivity in the hospital setting. METHODS We studie...

Residential combustion has been identified as one of the main sources of particulate matter (PM); fine particles are important because of their adverse effects on human health and the environment. In this thesis, fine particle emissions originating from residential pellet combustion were characterized in different operational situations and using different raw materials as pellet fuel. Moreover...

Airborne fine particle mass concentrations in Southern California have declined in recent years. Trends in sulfate and elemental carbon (EC) particle concentrations over the period 1982-1993 are consistent with this overall improvement in air quality and help to confirm some of the reasons for the changes that are seen. Fine particle sulfate concentrations have declined as a strict sulfur oxide...

This paper presents the results of an experimental investigation carried out to evaluate the effect of fly ash (FA) on fine sand compaction and its suitability as a material for embankments. The literature review demonstrates the lack of research on stabilization of sandy material using FA. The study is concerned with the role of FA content in stabilized soil physical characteristics. The main ...

Several magnetic fine particle systems have been studied with selective excitation double Mössbauer ~SEDM! spectroscopy. Static disorder, collective excitations, and superparamagnetic spin flips are all detected and their contributions quantified. Zero-field muon spin relaxation spectroscopy has been used to confirm these observations in one sample. A theoretical description of SEDM spectra in ...

fine particles silicoaluminophosphate-34 were synthesized by hydrothermal sol-gel method. the effect of crystallization time, as one of the important synthesis factors on particle size and crystallinity, kinetic and equilibrium adsorption, and selectivity of co2 / ch4 has been studied in this work. the adsorption isotherms are obtained at moderate gauge pressures (100-3000 kpa) and temperatures...