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Kevlar (para-aramid) [2] is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora.Developed by Stephanie Kwolek at DuPont in 1965, [3] [2] [4] the high-strength material was first used commercially in the early 1970s as a replacement for steel in racing tires.
Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste .
This plastic bucket has been used as an open-air flowerpot for some years. Photodegradation has made it brittle, causing part of it to break off when the bucket was moved. In polymer chemistry, photo-oxidation (sometimes: oxidative photodegradation) is the degradation of a polymer surface due to the combined action of light and oxygen. [1]
Industrial waste may pollute the nearby soil or adjacent water bodies, and can contaminate groundwater, lakes, streams, rivers or coastal waters. [1] Industrial waste is often mixed into municipal waste, making accurate assessments difficult. An estimate for the US goes as high as 7.6 billion tons of industrial waste produced annually, as of 2017.
Date/Time Thumbnail Dimensions User Comment; current: 14:37, 2 September 2021: 725 × 591 (147 KB): Mary Mark Ockerbloom: Uploaded a work by V. E. McKelvey from "Principles of the mineral resource classification system of the U.S. Bureau of Mines and U.S. Geological Survey : Geological Survey Bulletin 1450-A" by Thomas S. Kleppe and V. E. McKelvey, U.S. Bureau of Mines and U.S. Geological Survey.
The soil remediation intervention values indicate when the functional properties of the soil for humans, plants and animals is seriously impaired or threatened. They are representative of the level of contamination above which a serious case of soil contamination is deemed to exist.
Excellent thermal stability at temperature extremes, water repellency, chemical stability and resistance to petroleum products have made Kevlar KM2 an indispensable asset to the military personnel who use it every day." [1] "Kevlar KM2 fiber is a transversely isotropic material. Its tensile stress–strain response in the axial direction is ...
Polymer degradation is the reduction in the physical properties of a polymer, such as strength, caused by changes in its chemical composition.Polymers and particularly plastics are subject to degradation at all stages of their product life cycle, including during their initial processing, use, disposal into the environment and recycling. [1]