PARTICULATE MATTER SAMPLER ERRORS DUE TO THE INTERACTION OF PARTICLE SIZE AND SAMPLER PERFORMANCE CHARACTERISTICS: BACKGROUND AND THEORY

2013 ◽  
Author(s):  
M. D. Buser ◽  
C. B. Parnell ◽  
Jr. ◽  
B. W. Shaw ◽  
and R. E. Lacey
Author(s):  
Aline Krindges ◽  
Vanusca Dalosto Jahno ◽  
Fernando Morisso

Incorporation studies of particles in different substrates with herbal assets growing. The objective of this work was the preparation and characterization of micro/nanoparticles containing cymbopogon nardus essential oil; and the incorporation of them on bacterial cellulose. For the development of the membranes was used the static culture medium and for the preparation of micro/nanoparticles was used the nanoprecipitation methodology. The incorporation of micro/nanoparticles was performed on samples of bacterial cellulose in wet and dry form. For the characterization of micro/nanoparticles were carried out analysis of SEM, zeta potential and particle size. For the verification of the incorporation of particulate matter in cellulose, analyses were conducted of SEM and FTIR. The results showed that it is possible the production and incorporation of micro/nanoparticles containing essential oil in bacterial cellulose membranes in wet form with ethanol.


1998 ◽  
Vol 38 (6) ◽  
pp. 327-335
Author(s):  
Yasunori Kozuki ◽  
Yoshihiko Hosoi ◽  
Hitoshi Murakami ◽  
Katuhiro Kawamoto

In order to clarify the origin and behavior of suspended particulate matter (SPM) in a tidal river, variation of SPM in a tidal river was investigated with regard to its size and constituents. SPM was separated into three groups according to size. Change of contents of titanium and organic substances of each group of SPM was examined. SPM which was discharged by run-off was transported with decomposition and sedimentation in a tidal river. Concentration of SPM with a particle size greater than 0.45 μm increased due to resuspension in a tidal river. Origin of SPM with a size of less than 0.45 μm at upstream areas was from natural soil and most of such SPM which had been transported settled near a river mouth. It was determined from examination of the CN ratio and the ratio of the number of attached bacteria to free bacteria that SPM with a size greater than 1.0 μm at upstream areas was decomposing intensively. At the downstream areas, SPM with a size of less than 0.45 μm came from the sea. SPM with particle size greater than 1.0 μm consisted of plankton and substances which were decomposed sufficiently while flowing.


Author(s):  
R. T. Jones ◽  
W. G. D. Lugton ◽  
S. R. Massey ◽  
R. B. Richardson

AbstractWhen studying the distribution of smoke deposited in the lung, it is necessary to use a tracer which indicates the levels of particulate matter deposited at various sites. Because the site of deposition can be dependent on the particle size of the aerosol, it is important that the tracer should be uniformly distributed with respect to particle size, otherwise the levels of particulate matter may be wrongly estimated. The distributions in the smoke from a cigarette containing flue-cured tobacco of three possible tracers (dotriacontane, hexadecane and decachlorobiphenyl) have been measured; alI three show a slight dependence but probably not sufficient to exclude them from possible use in inhalation studies. However, because of the different environment which exists in the lung, and the possible dependence of the results on the type of tobacco, it should not be assumed that there are no selective effects


2003 ◽  
Vol 13 (03n04) ◽  
pp. 133-139 ◽  
Author(s):  
F. ALDAPE ◽  
J. FLORES M.

Samples of airborne particulate matter were collected in four sites along an east-west line from the Popocatépetl volcano after the eruption episode of June 30, 1997. The Popocatépetl volcano, with variable activity since it was known, is currently under low but continuous activity prolonged for almost one decade, with occasional moderate eruption episodes producing mainly fumes, ashes and volcanic dusts. The main objective of this study is to determine whether or not some elements have increased their presence in the atmosphere as a result of the volcanic activity, and also if some others, not usually found in urban aerosols, have appeared because of the same reason. In addition, the information obtained will be a source of scientific data for health risk assessment of the population exposed to volcanic emanations. The sample collection was performed on alternate days from July 10 to August 13 1997 in Puebla and Atlixco in Puebla State. Tlalpan within Mexico City, and Salazar in the State of Mexico. Two samples a day were taken in two periods: 7-19 h and 19-7 h. The samplers separated particles into two particle size fractions. PM25 and PM15. Elemental concentrations were determined by PIXE and the results obtained showed increased concentrations of mainly Ti and Fe in all sampling sites, thus indicating a long range transportation of volcanic dusts in both particle size fractions. Concentrations of Ti were found clearly above the average values of urban areas such as Mexico City, and although this element can be considered of low toxicity, the biological, metabolic and toxic effects on human beings are still under investigation.


Author(s):  
K A Kazim ◽  
B Maiti ◽  
P Chand

Centrifugal pumps are being used increasingly for transportation of slurries through pipelines. To design a slurry handling system it is essential to have a knowledge of the effects of suspended solids on the pump performance. A new correlation to predict the head reduction factor for centrifugal pumps handling solids has been developed. This correlation takes into account the individual effect of particle size, particle size distribution, specific gravity and concentration of solids on the centrifugal pump performance characteristics. The range of validity of the correlation has been verified by experiment and by using experimental data available from the literature. The present correlation shows better agreement with the experimental data than existing correlations.


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