Pollens

Brownian movement The rapid and random movement of particles of a colloidal sol, observed brightly lit against a dark ground. First observed with a pollen suspension. The Brownian movement is due to the impact on the dispersed particles of the molecules of the dispersion medium. As the particles increase in size, the probability of unequal bombardment from different sides decreases, and eventually collisions from all sides cancel out and the Brownian movement becomes imperceptible at a particle size of about 3-4/z. From the characteristics of the movement, Perrin calculated Avogadro s number L. 

SWS are useful to obtain direct indications of hydrocarbons (under UV light) and to differentiate between oil and gas. The technique is applied extensively to sample microfossils and pollen for stratigraphic analysis (age dating, correlation, depositional environment). Qualitative inspection of porosity is possible, but very often the sampling process results in a severe crushing of the sample thus obscuring the true porosity and permeability. 

Meanwhile, in a stateiy iaboratory atop a hill, the second finest alchemist in the land cast her sight beyond her potions and upon the landscape below. The troubles in her land prompted her to speak aloud, "How have things come to this Although I am pleased for the good fortune that has come to my friends who contract and build dungeons, and who enforce the bee pollen laws, I cannot help but feel that...that...aw fucketh it ". And for no... 

Particle size range (um) Ions Nuclei Visabilit> Suspended or settleable nonairbome Uisptersion aerosol Condensation aerosol Pollen and spores Sedimenlatiofi,. lifiusion, and settling... 

How does the diameter of airborne pollen grains compare with the diameter of a human hair ... 

Forest systems also act as sources of CO2 when controlled or uncontrolled burning and decay of litter occur. In addition, release of ethylene occurs during the flowering of various species. One additional form of emission to the atmosphere is the release of pollen grains. Pollen is essential to the reproductive cycle of most forest systems but becomes a human health hazard for individuals susceptible to hay fever. The contribution of sulfur from forests in the form of dimethyl sulfide is considered to be about 10-25% of the total amount released by soils and vegetation (12). 

The gases also have other constituents mixed with them, typical ones being dusts, pollens, bacteria, viruses, mold spores, smoke particles, and the products of industrial activity such as SO2, H2, and S. Volcanic activity also adds various gases and dusts to the atmosphere. 

Outdoor inhalation exposure is mainly due to traffic, energy production, heating, and natural factors such as pollen and mineral dusts. These outdoor sources of pollution also affect indoor air quality. The indoor concentration is typically 20-70% of the corresponding outdoor concentration. Occasionally the indoor concentrations of an external pollutant (especially radon) may even exceed the concentrations outdoors. ... 

The problem of allergies has increased during the last few years. The tendency to develop allergies and asthma is not well understood, but a number of pollutants can trigger the reaction, for instance, airborne allergens such as pollen,... 

For reasons of hygiene, the filter should be replaced after the pollen and spore season in the autumn. In the case of high demand, filters can also be changed in the spring after the heating season to eliminate odorous combustion products. 

Air treatment Any technique used to control the temperature, moisture content, or levels of dusts, gases, vapors, pollens, bacteria or viruses in air. 

Allergens Pollutants that may cause an allergy, including pollens, dusts, animal dander, insect debris, mold and fungi spores. 

Bio-aerosol A general term relating to airborne viruses, bacteria, pollen, and fungus spores. 

Pollen Small particles of the male fertilizing seeds of plant life, which may cause various allergic reactions especially of the respiratory tract, known as hay fever. 

Blumen blatt, n. petal. erde, /, garden mold, gelb, n. any yellow flower pigment. kohl, m. cauhflower, seite, /. (Leather) hair side, staub, m. pollen. tee, m. imperial tea. topf, m. flower pot. 

Samen-haar, n. (Bot.) seed hair, coma, -hefe, /. seed yeaat. -keim, m. germ, embryo, -kem, m. seed kernel (Bot.) endosperm Physiol.) spermatic nucleus, -lappen, m. seed lobe, cotyledon, -ol, n. seed oil. -pflan-zen, /.pi. seed plants, Spermatophyta. -probe, /. seed test or sample, -saift, m. seminal fluid, -staub, m. pollen, -tierchen, n. sp< rmatozoon. -zelle, /. seminal cell, spertpatozoon. -zucker, m. quercitol, quer-cite. ... 

Staub, m. dust powder pollen, -abscheider, m. dust separator. 

By number count the great majority of particles in the outside air are likely to be less than 1 pm. By weight, these small particles will account for a very small proportion of the sample. A filter with a high efficiency measured by weight of particles trapped may be almost transparent to the small ones. Very high counts can be found in rural areas from pollen or agricultural activities. 

Pollens Mould spores Fine ash Bacteria Tobacco smoke Viruses... 

An allergen is usually an inert substance (e.g. pollen, house dust mite faeces) that in some individuals can trigger the generation of an (inappropriate) antigenic response. Mediated by TH2 lymphocytes, it causes B-Lymphocytes to produce lgE. Subsequent exposure of a sensitized individual to the allergen is therefore able to cross-link IgE antibodies on the surface of mast cells and trigger an immune response and histamine release. 

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