Introduction
The components of the weather cycles responsible for the deterioration of most materials are non-ionizing radiation, atmospheric temperature and moisture in its various forms. This, combined with the effects of wind and atmospheric gases and pollutants. Although the ultraviolet (UV) portion of solar radiation is mainly responsible for initiating weathering effects, the visible and near-infrared portions can also contribute to the weathering processes. Colored materials are susceptible to visible radiation, and near-infrared radiation can accelerate chemical reactions by raising the material temperature. The other factors act synergistically with solar radiation to significantly influence the weathering processes. All weather factors, including the quality and quantity of sunlight, vary with geographic location, time of day and year, and climatalogical conditions. In order to fully understand and predict the effect of weather on materials, data is required on each factor that may contribute to degradation.
Read more about this topic: Factors Of Polymer Weathering
Famous quotes containing the word introduction:
“For the introduction of a new kind of music must be shunned as imperiling the whole state; since styles of music are never disturbed without affecting the most important political institutions.”
—Plato (c. 427–347 B.C.)
“Such is oftenest the young man’s introduction to the forest, and the most original part of himself. He goes thither at first as a hunter and fisher, until at last, if he has the seeds of a better life in him, he distinguishes his proper objects, as a poet or naturalist it may be, and leaves the gun and fish-pole behind. The mass of men are still and always young in this respect.”
—Henry David Thoreau (1817–1862)
“We used chamber-pots a good deal.... My mother ... loved to repeat: “When did the queen reign over China?” This whimsical and harmless scatological pun was my first introduction to the wonderful world of verbal transformations, and also a first perception that a joke need not be funny to give pleasure.”
—Angela Carter (1940–1992)