Aerosol characteristics

Fig. 4. Some important aerosol characteristics. Data modified from Reference 26 which was adopted ia part from Reference 27.

Finally, whenever theoretical or experimental unattached fractions are reported, the aerosol characteristics Og, CMD and N must also be reported to allow proper interpretation of the results. 

Table I. Calculated activity median diameter for attached radon daughters from measured aerosol characteristics (Tu, 1986).

The swirl number, a dimensionless ratio of the angular momentum to the product of the axial momentum and the radium of the burner, can be varied through separate control of the two secondary air streams in order to study various burner designs. The air flows were measured using sharp edged orifices. Control of the air flows and calibration of the coal feeder made it possible to duplicate combustion conditions as determined both by exhaust gas analysis (CO, CO2, O2, NO, NOx) and aerosol characteristics. 

Reid, J. S., R. G. Flocchini, T. A. Cahill, and R. S. Ruther, Local Meteorological, Transport, and Source Aerosol Characteristics of Late Autumn Owens Lake (Dry) Dust Storms, Atmos. Environ., 28, 1699-1706 (1994). 

Anderson, J., and V. K. Saxena, Temporal Changes of Mount Pinatubo Aerosol Characteristics over Northern Midlatitudes Derived from SAGE II Extinction Measurements, J. Geophys. Res., 101, 19455-19463 (1996). 

Based on these results, generation temperatures of 895°C and 500°C were chosen for Pb and , respectively. The aerosol characteristics are given below in Table I. Electron microscopic examination of the aerosol samples showed spherical particles in the 0.01 to 1.0 ym size range—in agreement with the electrical aerosol analyzer data. 

Treffeisen R, Tunved P, Strom J, Herber A, Bareiss J, Helbig A, Stone RS, Hoyningen-Huene W, Krejci R, Stohl A, Neuber R (2007) Arctic smoke - aerosol characteristics during a record smoke event in the European Arctic and its radiative impact. Atmos Chem Phys 7 3035-3053... 

A thorough analysis of atmospheric transport and deposition to the Great Lakes has been carried out using the HYSPLIT model developed by the US National Atmospheric and Oceanic Administration (NOAA) [28,29]. An emissions inventory of PCDD/Fs for North America in 1996 was used as input to the model. Factors considered in the fate and distribution were meteorological data, vapor-particle partitioning, aerosol characteristics, reaction with hydroxyl radicals, photolysis, and dry and wet deposition. The model was generally satisfactory at estimating fluxes, except for HpCDD and OCDD, which appeared to be underestimated by about a factor of four. The model output was summarized as 2378-TeCDD toxic equivalent concentrations (TEQs) based on the WHO mammalian 2378-TeCDD toxic equivalent factors (TEFs) [30]. Since HpCDD and OCDD were estimated to contribute only 2% of TEQs, the model was considered to be valid for the purpose intended. 

An important problem is to provide an interactive consideration of the three types of aerosol impact on the ABL, clouds, and the indirect RF mentioned above. Solution of this problem was one of the main objectives of the second field observational experiment (ACE-2) on studies into aerosol characteristics in 1997 in the Canary Islands. Part of the program of this experiment (called CloudColumn ) was especially dedicated to a study of the indirect impact of anthropogenic aerosol on climate. In 1999, the European Commission supported further studies in this direction within the PACE project on the development of parameterization schemes for the impact of aerosol on climate. 

Brenguier et al. (2003) discussed the ACE-2 CC project, one of the five projects accomplished within the ACE-2 program of the second field experiment on studies of aerosol characteristics with the aim of understanding the indirect climatic impact of aerosol for marine stratocumulus clouds and to substantiate the strategy of closed aerosol-cloud-radiation experiments. Observations within the CC project were made in June-July 1997 in the Canary Islands using instruments onboard three flying laboratories and installed at a surface network. 

The Respimat inhaler was recently launched in Germany as a combination product of fenoterol and ipratropium hydrobromide (Berodual) and was licensed for the treatment of chronic obstructive airway disease. A large body of literature now exists documenting the aerosol characteristics and clinical performance of the Respimat inhaler with a number of different drugs [274,275]. Aerosolized formulations include the steroids budesonide and flunisolide in addition to the p agonist fenoterol as well as the commercially available combination product of fenoterol and ipratropium bromide [276-281],... 

Artaxo, P., W. Maenhaut, H. Storms, and R. Van Grieken. 1990. Aerosol characteristics and sources for the Amazon Basin during the wet season. Journal of Geophysical Research 95 16971-16985. 

Nebulizers fitted with a T-mouthpiece have an unrestricted flow of ambient air passing through the nebulizer output, supplying inhaled air flow, which effectively increases drug output. In vented nebulizers, the inhaled air must flow through the droplet production region. Therefore, the breathing pattern of the patient has an effect on the aerosol characteristics produced by such devices. The delivery efficiency of... 

Ruijgrok EJ, Vulto AG, Van Etten EW. Aerosol delivery of amphotericin B Desoxycholate (Fungizone) and liposomal amphotericin B (AmBisome) aerosol characteristics and in-vivo amphotericin B deposiiton in rats. J Pharm Pharmacol 52(6) 619-627, 2000. 

Optical methods can. In some cases, be used to measure aerosol characteristics in the original gas stream without withdrawing a sample. In most cases, however, it is necessary to sample Irom a flowing gas through a tube into an instrument, such as those discussed in the following sections. 

It is inappropriate to use any pMDI with any spacer without considering the aerosol characteristics, even if the pMDI adaptor fits. The use of a universal spacer common to aU pMDIs will result in unpredictable dosing. 

In addition to the total lung dose, the distribution of aerosol within the lungs may affect the clinical response. The aerosol characteristics are changed in a spacer, resulting in smaller particles that are likely to penetrate into smaller airways. However, little is known about the exact anatomic targets of various drugs within the airways. 

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