Mass Median Diameter

2016 ◽  
Author(s):  
Monica Nordberg ◽  
John H. Duffus ◽  
Douglas M. Templeton
Keyword(s):  
Median Diameter ◽  
Mass Median ◽  
Mass Median Diameter

Aircraft Applications of Insecticides in East Africa. VI.—Applications of a coarse Aerosol containning DDT to control the Tsetse Flies, Glossina morsitans Westw., Glossina swynnertoni Aust. and Glossina pallidipes Aust.

1954 ◽  
Vol 45 (3) ◽  
pp. 585-603 ◽  
Author(s):  
K. S. Hocking ◽  
D. Yeo ◽  
D. G. Anstey
Keyword(s):  
Random Effects ◽  
Glossina Pallidipes ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Median Diameter ◽  
Coarse Aerosol ◽  
Savannah Woodland ◽  
Mass Median ◽  
Glossina Swynnertoni ◽  
Mass Median Diameter

An experiment is described where applications of a coarse aerosol were made to savannah woodland containing the tsetse flies, Glossina moritans Westw., G. swynnertoni Aust. and G. pallidipes Aust.Seven applications were made, each at a nominal dosage of 0·25 lb. of technical DDT per acre and 0·25 gallons of solution per acre. The applications in any particular part of the treaed woodland covered an interval of 90 days, or rather more than two pupal periods.The coarse aerosol was produced by emitting the insecticidal solution under pressure through fine nozzles fitted to a boom. It had a mass median diameter of approximately 60 microns, and droplet dismeters varied from a few microns to approximately 200 microns.The population of G. pallidipes was so drastically reduced that it has subsequently dies out. The reduction of G. morsitans was approximately 95 per cent. The differences between the reductions are attributed mainly to differences between the ease with which the three species can be killed. It is pointed out that this is not necessarily equivalent to differences in susceptibility.Comparisons are made with previous experiments, and the different results of the various experiments are difficult to explian satisfactory. The increased cover in savannah areas during the leafy period may have reduced the effectiveness of the applications, and the total periods covered by the various series of applications were probably also important. Random effects, leading to ineffective treatments, may also be important.Costs are discussed.

The Possible Site of Action of Sodium Cromoglycate Assessed by Exercise Challenge

1974 ◽  
Vol 46 (2) ◽  
pp. 265-272 ◽  
Author(s):  
S. Godfrey ◽  
E. Zeidifard ◽  
K. Brown ◽  
J. H. Bell
Keyword(s):  
Sodium Cromoglycate ◽  
Particle Sizes ◽  
Post Exercise ◽  
Asthmatic Patients ◽  
Exercise Challenge ◽  
Site Of Action ◽  
Median Diameter ◽  
Mass Median ◽  
Spinning Disc ◽  
Mass Median Diameter

1. The protective effect of different particle sizes of sodium cromoglycate (SCG) was assessed by exercise challenge in nine asthmatic patients. 2. SCG particles of 11·7 μm or 2·0 μm mass median diameter were generated by a spinning disc and compared with lactose placebo particles. The drugs were given 10 min before a 6 min run on a treadmill. 3. The post-exercise bronchoconstriction caused a 48% fall in peak flow rate in the placebo test, a 41% fall after the large SCG particles and a 20% fall after the small particles. 4. It is concluded that the site of action of SCG is probably in the smallest airways.

Aircraft Applications of Insecticides in East Africa. II.—An experimental Attempt to Produce a Fly-free Corridor through a Belt of Tsetse-infested Woodland

1953 ◽  
Vol 44 (3) ◽  
pp. 601-609 ◽  
Author(s):  
K. S. Hocking ◽  
H. C. M. Parr ◽  
D. Yeo ◽  
P. A. Robins
Keyword(s):  
East Africa ◽  
Wind Direction ◽  
Tsetse Fly ◽  
Low Level ◽  
Median Diameter ◽  
Savannah Woodland ◽  
Mass Median ◽  
Mass Median Diameter

An experimental attempt was made to produce a fly-free corridor through a belt of savannah woodland containing the tsetse fly G. swynnertoni.An area two miles wide and four miles long was treated with a coarse spray of a 4·6 per cent, w/v solution of DDT in Shell Diesoline. The dosage per application was 0·5 gallons per acre, and seven applications were made, at intervals of approximately two weeks, so that the treatment covered two pupal periods.The fly density had fallen to a very low level by the end of the experiment, and the area remained virtually free from flies for the subsequent two months. An examination of the data suggests, however, that the fly population was maintained largely by immigrant flies, and was certainly subject to wide variations, and it seems certain that the effect of the applications would have been considerably less upon a stable, self-supporting population.The drop spectrum of the ground deposit had a mass median diameter of 0·35 mm., and the recovery of insecticide in the area was approximately 60 per cent. Leeward and under sides of obstacles did not receive a dose although in some cases dosages were obtained on apparently leeward sides, probably because of local reversals of wind direction.

The Correlation of Drop-Size Distributions in Fuel Nozzle Sprays—Part I: The Drop-Size/Volume-Fraction Distribution

1977 ◽  
Vol 99 (3) ◽  
pp. 309-314 ◽  
Author(s):  
H. C. Simmons
Keyword(s):  
Drop Size ◽  
Volume Fraction ◽  
Operating Conditions ◽  
Different Types ◽  
Median Diameter ◽  
Fraction Distribution ◽  
Fuel Nozzle ◽  
Drop Size Distributions ◽  
Mass Median ◽  
Mass Median Diameter

The paper presents data on the drop-size/volume-fraction distributions of sprays observed with a large number of gas-turbine fuel nozzles of different types including both pressure and air-atomizers, using a range of fuel viscosities, at a variety of operating conditions. The data were obtained by both optical and wax-droplet methods. It is shown that a universal nondimensional correlation can be established for all the fuel nozzles when the drop-size is normalized to the mass median diameter. The correlation enables prediction of the drop-size/volume-fraction distribution for a spray given only the mass median or Sauter mean diameter.

scholarly journals Mass median diameter of environmental particulates assessed by cascade centripeter

Sangyo Igaku ◽  
1968 ◽  
Vol 10 (4) ◽  
pp. 226-227
Author(s):  
T. Toyama ◽  
H. Kondo ◽  
M. Kusumoto ◽  
H. Momotani
Keyword(s):  
Median Diameter ◽  
Mass Median ◽  
Mass Median Diameter

Mass Median Diameter

2016 ◽  
Author(s):  
John H. Duffus ◽  
Monica Nordberg ◽  
Douglas M. Templeton
Keyword(s):  
Median Diameter ◽  
Mass Median ◽  
Mass Median Diameter

Aircraft Applications of Insecticides in East Africa. IX.—Further Experiments on the Deposition in open Country of a coarse Aerosol released from an Aircraft

1954 ◽  
Vol 45 (4) ◽  
pp. 745-749 ◽  
Author(s):  
D. Yeo
Keyword(s):  
Wind Speed ◽  
Temperature Inversion ◽  
Large Temperature ◽  
Measured Parameter ◽  
Low Wind Speed ◽  
Median Diameter ◽  
Open Country ◽  
Coarse Aerosol ◽  
Mass Median ◽  
Mass Median Diameter

Further experiments have been carried out to investigate how a coarse aerosol, released from a low-flying aircraft, is deposited upon the ground in open country. The aerosol had a mass median diameter of approximately 80 microns, and was produced by a boom-and-nozzle apparatus.The aircraft height was 65 ft. It is shown that the rate of deposition is related to the degree of atmospheric turbulence, of which a simple and easily measured parameter is given. The rate of deposition is greatest when there is a large temperature inversion and a low wind speed.A comparison is made with previous work where the aircraft height was 30 ft. Within the limits investigated, an increase in aircraft height reduces the deposits near the line of emission, but does not greatly affect the total amount that deposits within 150–200 seconds of production of the aerosol.

Experimental Investigation on Atomization Properties of Coal-Water Paste Fired Into Pressurized Fluidized Bed Combustor

2003 ◽  
Author(s):  
Ping Lu ◽  
Mingyao Zhang
Keyword(s):  
Particle Size ◽  
Mass Ratio ◽  
Piv Measurement ◽  
Median Diameter ◽  
Processing Software ◽  
Image Processing Software ◽  
Fluidized Bed Combustor ◽  
Mass Median ◽  
Mass Median Diameter

According to the properties of coal-water paste (CWP), a series of experimental devices were constructed to study the atomizing characteristics of the CWP nozzle deeply. The particle size and its distribution of several types of atomizing nozzle of CWP in the spray are measured by PIV measurement and newly developed image processing software. The influences of every factor on the atomizing properties are analyzed. The atomizing experimental results show that atomizing quality of CWP was found to correlate with the characteristics of CWP, air to CWP mass ratio, atomizing air motion, coal particle size distribution and the structure of atomizer etc. mass median diameter (MMD) of atomizing particle decrease with the increase of gas to CWP mass ratio, and the proper type of nozzle and proper parameters for engineering are suggested.

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