Accelerated weathering

In the winter months, significant benefits are derived from the use of concretes that contain cold-weather accelerating (CWA) admixtures with antifreeze properties. The economic benefits are derived from their ability... 

Resistance to light and weather generally depends on the chemical composition, structure, defects, particle shape and size, and concentration of the pigment [1.53], However, these properties also depend on the medium in which the pigment is used. Testing is carried out by open-air weathering, accelerated weathering, and chemical test methods. 

Frequently, pure liquid samples produce charts that are essentially a perfect match for each peak, both by retention and quantity. This allows a quick and certain identification. However, as individual samples of accelerants are "weathered" by exposure to fire and air the more volatile, low-boiling fractions are consumed or lost through evaporation. The compositions of some accelerant mixtures such as gasoline are rapidly altered. With passage of time., "weathered" accelerant mixtures become more difficult to compare with charts of standard mixtures. 

Arrhenius equation An equation that refers to the rates of reaction versus temperature. See chemical reaction versus temperature rate, arrowhead See extruder film arrowhead, art and weatherability See weatherability, accelerated. 

The materials are controlled by the lithology on the formative region, earthquake and weathering accelerate the cracking of soil and rock and the unstable of slope that are the basic materials of debris flow occurrence. 

Keywords photooxidation, UV absorbers (UVA), outdoor performance, weathering, accelerated weathering, kinetic chain length, photoinitiator, Norrish reactions, peroxide decomposer, hindered amine light stabilizers (HALS), photosensitizer, transition metal complex, UV stabilizer, time-controlled stabilization, reactive antioxidants, polymeric antioxidants. 

Keywords Reciprocity UV intensity Weathering Acceleration Correlation ORWET Polystyrene Irradiance Temperature Ultra-Accelerated Weathering System UA EMMA Exposure Exhapolation ASTM G90 Color Outdoor Static Dynamic Hypervolume... 

Bauer, D.R. Interpreting weathering acceleration factors for automotive coatings using exposure models. Polym. Degrad. Stab. 69, 305-316 (2000)... 

Haillant, O., Dumbleton, D., Zielnik, A. An Arrhenius approach to estimating organic photovoltaic module weathering acceleration faetors. Sol. Energy Mater. Sol. Cells 95, 1889-1895 (2011)... 

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