Webphotoaddition of maleimide to benzene. (iii) Reactions in which the benzene ring is (a) excited, or (b) undergoes photochemical charge transfer. Examples of type (a) include photoisomeriza-tions to fulvene, benzvalene, Dewar-benzene etc., and the photoaddition of simple mono-olefins and 1,3-dienes, whereas type (b) is illustrated by the WebA tan line is a visually clear division on the human skin between an area of pronounced comparative paleness relative to other areas that have been suntanned by exposure to ultraviolet (UV) radiation or by sunless tanning.The source of the radiation may be the sun, or artificial UV sources such as tanning lamps.Tan lines are usually an inadvertent result …

Polymorphous light eruption - Symptoms and causes - Mayo Clinic

WebTanning refers to the succession of chemical processes by which raw animal skins are transformed into leather. This complex procedure has a few key stages, which we will elaborate on later. It follows that a tannery is a kind of factory or workshop where this entire process takes place. Webtanning, chemical treatment of raw animal hide or skin to convert it into leather. A tanning agent displaces water from the interstices between the protein fibres and cements these fibres together. The three most widely used tanning agents are vegetable tannin, mineral salts such as chromium sulfate, and fish or animal oil. See also leather. city charters in oregon

Photoaddition and photo fragmentation reaction - SlideShare

Webphotoaddition noun Any bimolecular addition reaction that takes place under the influence of light How to pronounce photoaddition? David US English Zira US English How to say … WebThe meaning of TAN is to make (skin) tan especially by exposure to the sun. How to use tan in a sentence. WebClients should be taught to avoid "photo-addition" which refers to: Tanning both indoors and outdoors within a 24-hour period The outer-most skin layer where tanning takes place can … city chat rooms