Determination of size spectrum of chloride giant condensation nuclei

1959 ◽  
Vol 3 (4) ◽  
pp. 393-402 ◽  
Author(s):  
Josef Podzimek
Keyword(s):  
Size Spectrum ◽  
Condensation Nuclei

Theoretical Aspccts of Cloud Drop Distributions

1949 ◽  
Vol 2 (3) ◽  
pp. 376 ◽  
Author(s):  
EB Kraus ◽  
B Smith
Keyword(s):  
Cooling Rate ◽  
Drop Size ◽  
Initial Temperature ◽  
Theoretical Study ◽  
Air Pressure ◽  
Size Spectrum ◽  
Condensation Nuclei ◽  
Cloud Drop ◽  
Rate Of Cooling

A theoretical study indicates that the number and size of the drops formed in a cloud vary with the rate of cooling, the initial temperature, and the air pressure. The faster the cooling rate, the lower the initial temperature, and the lower the altitude, the greater is the number of drops and the smaller their size. The drop size spectrum also depends, to a large extent, on the number of available condensation nuclei. Furthermore, it tends to be widened by sedimentation and turbulence.

A Continuous Size Spectrum for Particulate Matter in the Sea

1967 ◽  
Vol 24 (5) ◽  
pp. 909-915 ◽  
Author(s):  
R. W. Sheldon ◽  
T. R. Parsons
Keyword(s):  
Particle Diameter ◽  
Particulate Material ◽  
Size Spectrum ◽  
Particulate Carbon ◽  
Particle Volume ◽  
Carbon And Nitrogen ◽  
Total Particle ◽  
Volume Measurements ◽  
Good Agreement

The size spectrum of particulate material in seawater can easily be expressed as total particle volume versus the logarithm of particle diameter. This appears to be the most informative way to present the data and it is also aptly suited to the classical divisions of nanno-, micro-, and macroplankton.A realistic measure of the volume of irregularly shaped particles such as phytoplankton chains could be made with a Coulter Counter. Particle volume measurements were in good agreement with estimates based on microscopic determination of particle diameter. There were also highly significant correlations between total particle volume, as indicated by the counter, and particulate carbon and nitrogen.

The Application of Condensation Nuclei Monitors to Clean Rooms

1985 ◽  
Vol 28 (2) ◽  
pp. 34-36
Author(s):  
David Ensor ◽  
Robert Donovan
Keyword(s):  
Ultrafine Particles ◽  
Turn Of The Century ◽  
Size Spectrum ◽  
Adiabatic Expansion ◽  
Clean Room ◽  
Condensation Nuclei ◽  
Differential Mobility ◽  
Expansion Chamber ◽  
Diffusion Battery ◽  
Number Of Particles

The instrument often used by aerosol researchers to detect 0.1-μm and smaller particles is the condensation nuclei monitor. The instrument will provide information about ultrafine particles in the clean room unobtainable by any other means. The principle of operation is to grow the particles by the condensation of water or alcohol onto a size that can be detected optically. The instrument was invented at the turn of the century by John Aitken.1 His instrument was an adiabatic expansion chamber followed by counting with a microscope after the droplets had settled onto a slide. In the last few years, automatic instruments have been commercially available. Since the condensation nuclei counter only detects the total number of particles, a particle size preseparator needs to be used with the instrument to obtain size distribution information. One type of preseparator is the "diffusion battery," and another is a differential mobility separator. The present application of the instrument is as a research tool to quantify the size spectrum of particles less than 1 μm. Measurements of clean-room condensation nuclei will be presented under a number of situations.

On the determination of the diffusion coefficient of condensation nuclei using the static and dynamic methods

1956 ◽  
Vol 34 (1) ◽  
pp. 177-195 ◽  
Author(s):  
L. W. Pollak ◽  
T. C. O'Connor ◽  
A. L. Metnieks ◽  
R. Fürth
Keyword(s):  
Diffusion Coefficient ◽  
Condensation Nuclei ◽  
Dynamic Methods

scholarly journals Size distribution of EC and OC in the aerosol of Alpine valleys during summer and winter

2005 ◽  
Vol 5 (3) ◽  
pp. 3773-3809 ◽  
Author(s):  
J.-L. Jaffrezo ◽  
G. Aymoz ◽  
J. Cozic
Keyword(s):  
Chemical Species ◽  
Rural Site ◽  
Size Spectrum ◽  
Size Distributions ◽  
Formation Processes ◽  
Secondary Formation ◽  
Mass Fractions ◽  
Intensive Sampling ◽  
Alpine Valleys

Abstract. Collections of samples were conducted for the determination of the size distributions of EC and OC during the intensive sampling campaigns of the POVA program, in two Alpine valleys of the French Alps, in summer and in winter. The comparison of concentrations obtained for samples collected in parallel with impactor- and filter-based methods indicates that the correction of pyrolysis seems to work for the impactor samples despite non even deposits. The size distributions of the concentrations of EC and OC present large evolutions between winter and summer, and between a suburban and a rural site. In winter, an overwhelming proportion of the mass fraction of both species is found in the droplet and accumulation modes, often (but not always) in association with sulfate and other chemical species resulting from secondary formation processes. Some indications of gas/particles exchanges can be found for the other parts of the size spectrum (the Aitken and super micron modes) in the case of the rural site. In summer, the changes are more drastic with, according to the case, a dominant droplet or accumulation mode. Particularly at the rural site, the large extent of processing of the aerosol due to gas/particles exchanges is evident for the Aitken and super micron modes, with increasing of the OC mass fractions in these size ranges. All of these observations give indications on the degree of internal vs. external mixing of the species investigated in the different modes.

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