The definition of a greenhouse gas is at the same time very simple and very complicated for the ordinary man (or woman !) : such a gaz is “just” a gas mixed in the atmosphere thatabsorbs the infrared radiation emitted by the earth’s surface. We are not accustomed to these gases bec...
untiltheyreturntotheearth’secosystem.Airiscomposedofamultitudeofgases,vapors,andaerosolsthatallvaryinconcentration,dependingontime,locationofnearbysources,etc.Inaddition,thedefinitionofacontaminantdependsontheapplication.Airbornepollen,forexample,isaboontovegetation(andiscertainlynotacontaminant)asitistransportedfrom...
Harriet Burge (Boston) emphasized the serious lack of understanding of exposures to biological aerosols. She commented that pollen and spore levels are as- sociated with asthma, hospitalizations, and mo rtality. Burge remarked that a single inhaled ragweed pollen grain can produce symptoms in a ...
Air filters are used in home furnaces, offices, laboratories, clinics, hi-tech microelectronics manufacturing, chip and hard-drive production and the aerospace industry.Air filters efficiently capture a wide range of contaminants from the air, including dust, dirt, smoke, aerosols, odors, viruses, ...
The ma- jor focus of such studies has been the deposition and clearance of ambient aerosols. These factors are also of great importance in therapeutics inasmuch as the extent and duration of action of drugs depend upon their site of presentation and period of residence in the lung. The ...
Aerosols What may remain in the air for some time areaerosolizedvirus particles. So for example, you could imagine someone creating two issues when sneezing, the first are ejected droplets, which travel a short distance, then second, aerosolized virus particles that stay in the air for longer....
These latter have two antagonist effects on the ground temperature : being composed of water vapour (or droplets) that is a greenhouse gas, they are part of the “heat trap“, but, as they are highly reflexive for the sun rays, they also exert a “cooling effect” on...
These are in the form of continuous sheets or veils, grey or blue-gray. They are composed of ice crystals and water droplets. In its thinner areas, the sun can still be visible as a round, dim disk. These clouds may often form ahead of storms with continuous rain or snow. ...
inaerosols.Aerosolsproduce smaller and more numerous cloud droplets. These have the effect of increasing the reflectivity and hencealbedoof low cloud-tops (fig. 3). It follows that if aerosol levels decrease, the reverse will be the case. Of considerable relevance here are the limits on the ...
The other picture theatres in the city had, of course, to close their doors while the battle raged, but they are preparing to reopen. It is to be hoped that business will come back to them in increasing volume, and thus in some measure make amends for the slump which has been felt in...