Environmental effect weathering

Due to high application levels of plasticizers, their behavior with respect to environmental influences (weathering resistance) and impact on the polymer matrix (effect on optical properties or plastics lifetime) have to be tested. 

The main apparent technical problems posed in relation with these types of potential noise barriers would be their noise abatement capability, structural performance, fire resistance, weatherability, chemical activity, and environmental effects. To assess the quality of new products of such materials, a series of mechanical, noise abatement, and flammability tests should be performed on a number of samples from the panels made of recycled rubber products. The primary function of these panels, i.e., their noise abatement capability is among the most important aspect of their performance. 

Note that outdoor weathering can involve all four factors simultaneously. The subject of weathering is considered in Chapter 6. Chemicals are considered in Chapter 3, and heat in Chapter 4. Mechanical stress involves several aspects fatigue is considered in Chapters 5 and 11. Chapter 12 links mechanical and environmental effects. 

M. B. Neiman, Aging and Stabilization of Polymers, Consultants Bureau, New York, 1965. S. H. Pinner, Weathering and Degradation of Plastics, Columbine Press, Manchester, 1966. J. Voigt, Die Stabilisierung der Kunststoffe gegen Ucht und Wdrme, Springer, Berlin, 1967. D. V. Rosato and R. T. Schwartz, Environmental Effects on Polymeric Materials, Interscience, New York, 1968. 

The effect of high or low environmental temperature on skilled performance is important for industrial or service personnel. Operators often have to work in extreme thermal conditions, such as in furnaces or when they need to operate a pump in cold weather at night. Errors of omission are quite often due to the workers trying to minimize the time period they have to be exposed to high or low temperatures. Particular emphasis has been placed on the effects of cold on manual performance. Cold can affect muscular control, reducing such abilities as dexterity and strength. 

Dry air rising in the atmosphere has to expand as the pressure in the atmosphere decreases. This pV work decreases the temperature in a regular way, known as the adiabatic lapse rate, Td, which for the Earth is of order 9.8 Kkm-1. As the temperature decreases, condensable vapours begin to form and the work required for the expansion is used up in the latent heat of condensation of the vapour. In this case, the lapse rate for a condensable vapour, the saturated adiabatic lapse rate, is different. At a specific altitude the environmental lapse rate for a given parcel of air with a given humidity reaches a temperature that is the same as the saturated adiabatic lapse rate, when water condenses and clouds form Clouds in turn affect the albedo and the effective temperature of the planet. Convection of hot, wet (containing condensable vapour) air produces weather and precipitation. This initiates the water cycle in the atmosphere. Similar calculations may be performed for all gases, and cloud layers may be predicted in all atmospheres. 

The environment that plants experience includes the conditions in the soil as well as the "weather," or climate above ground. So mineral imbalances in the soil can be classified as environmental problems, just like drought or exposure to too much wind. Environmental problems can have direct effects, and also indirect effects they leave plants more vulnerable to attack from pathogens or pests. 

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