Aerosols conductivity measurement

To study the behavior of aerosol particles in the airways, experiments were conducted with hollow human and canine casts, which were complete from the trachea to 1-mm airways. These casts were connected to the inhalation device for aerosol bolus measurements and were ventilated by a piston pump. Aerosol boluses ventilated to a VL of less than 80 mL did not leave the cast ont of the 1-mm open-ended airways, bnt were deposited exclnsively in the airways of the cast (43,44). 

The surface a-activity on the samples for each exposed set of samples was compared. Each set of samples was exposed, and measured, a minimum of about five times to improve overall statistics. Experiments were conducted in the temperature range 19-22°C and at low relative humidity (10 to 40%). The aerosol concentration, mainly... 

To test the applicability of statistical techniques for determination of the species contributions to the scattering coefficient, a one-year study was conducted in 1979 at China Lake, California. Filter samples of aerosol particles smaller than 2 ym aerodynamic diameter were analyzed for total fine mass, major chemical species, and the time average particle absorption coefficient, bg. At the same time and location, bgp was measured with a sensitive nephelometer. A total of 61 samples were analyzed. Multiple regression analysis was applied to the average particle scattering coefficient and mass concentrations for each filter sample to estimate aj and each species contribution to light scattering, bgn-j. Supplementary measurements of the chemical-size distribution were used for theoretical estimates of each b pj as a test of the effectiveness of the statistical approach. 

The composition distribution of the particles produced in a laboratory pulverized coal combustor will be explored in this paper using aerosol classification techniques capable of resolving the composition distribution to 0.03 ym diameter. Unlike previous attempts to measure the composition distribution, the particles were classfied directly, without having to resort to resuspension, using calibrated instruments. Experiments were conducted in a laboratory combustor in which operating parameters can be varied over a wide range. Data are presented which demonstrate that the composition of fine particles varies substantially with combustion conditions and does, under some conditions, differ considerably from that of the bulk ash. 

PERSONAL MONITORING IS A RELATIVELY NEW CONCEPT in community air pollution measurement research (1-3). This fact is not surprising because most air pollution investigations have been directed toward the characterization of the ambient atmosphere, the observation of pollutant trends, the acquisition of data on chemical kinetic parameters and on the physical properties of aerosols, and the determination of compliance to national and other standards (4). Before the late 1970s, research on personal monitors was primarily conducted in industrial settings (5, 6) because American Confer-... 

Studies of the dubnium behavior. 930 experiments were conducted with 262Db produced at the Berkeley 88-Inch Cyclotron in the 249Bk(lsO,5n) reaction. Extractions were performed in the Aliquat336/Cl - HC1 system with a 50 s cyclic collection time of the KC1 aerosol on a Kel-F slider in ARCA II. The reaction products were fed onto the column in 10 M HC1 followed by the elution of a Ta fraction in 6 M HC1 and a Nb,Pa fraction in 6 M HNO3/O.OI5 M HF. The effluents were continuously sprayed through a 60 pm nozzle onto hot Ta discs on which they were evaporated to dryness by hot He gas and infrared light. Start of measurement of the activities was 60 s (Ta fraction) and 76 s (Nb, Pa fraction) after the end of collection, respectively. 

Borkovec et al. [59] also reported on a two-stage percolation process for the ME AOT (Aerosol OT, bis(2-ethylhexyl)sodium sulfosuccinate) system AOT-decane-water. The structural inversions were investigated using viscosity, conductivity, and electro-optical effect measurements. The viscosity results showed a characteristic profile with two maxima, which was interpreted as evidence for two symmetrical percolation processes an oil percolation on the water-rich side of the phase diagram and a water percolation process on the oil-rich side. 

Monitoring of changes in the radioecological situation around each radiation-hazardous enterprise is the main methodic principle of information survey. Measurements, which frequency and scope depend on location and specific condition of every environmental contamination source, are conducted as follows monitoring of seawater, aerosols - every day dry land, atmospheric depositions - every week drinking water - every month coastal and marine vegetation, fish, benthos - once a year. 

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