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The name was coined in 1899 by Leon Marchlewski, who first purified the compound and studied some of its chemical properties. [7] F. E. Withers and F. E. Caruth first attributed the toxic properties of the cotton seed (known since the 19th c.) to gossypol in 1915, [8] and its chemical formula was established in 1927 by Earl Perry Clark (1892 ...
Expansive clay, also called expansive soil, is a clay soil prone to large volume changes (swelling and shrinking) directly related to changes in water content. [1] Soils with a high content of expansive minerals can form deep cracks in drier seasons or years; such soils are called vertisols.
Age and origin of the source material determine the chemical structure of humic substances. In general, humic substances derived from soil and peat (which takes hundreds to thousands of years to form) have higher molecular weight, higher amounts of O and N, more carbohydrate units, and fewer polyaromatic units than humic substances derived from ...
Other soils which have a mollic epipedon are classified as Vertisols because high shrink swell characteristics and relatively high clay contents dominate over the mollic epipedon. These soils are especially common in parts of South America in the Paraná River basin receiving abundant but erratic rainfall and extensive deposition of clay -rich ...
Due to the physical and chemical properties of some clays [4] (such as the Lias Group) large swelling occurs when water is absorbed. Conversely when the water dries up these clays contract (shrink). The presence of these clay minerals is what allows soils to have the capacity to shrink and swell.
Bepanthen eye and nose ointment (Germany) A vial of nasal spray containing panthenol, manufactured in Italy In pharmaceuticals, cosmetics, and personal-care products, panthenol is a moisturizer and humectant, used in ointments, lotions, shampoos, nasal sprays, eye drops, lozenges, and cleaning solutions for contact lenses.
Unweatherable parent materials – sand, iron oxide, aluminium oxide, kaolinite clay. Erosion – common on shoulder slopes; other kinds also important.; Deposition – continuous, repeated deposition of new parent materials by flood as diluvium, aeolian processes which means by wind, slope processes as colluvium, mudflows, other means.
Most research on anthropogenic soils describes specific aspects of their biology, chemistry or physical properties, cultural heritage and human geography, erosion, wastes, pollution, fertilizer management, and taxonomy. Very few of them, [3] [4] [5] try to answer to the question: How fast do they start pedogenesis (viz., differentiating horizons)?