In the crystal structure, the title compound, C24H22O8, lies on a twofold rotation axis and the asymmetric unit comprises one half-molecule.The dihedral angle formed by the coumarin unit with the symmetry-related part is 74.78 (14)°.One Sunglasses of the methoxy groups attached to the coumarin unit is considerably twisted, making

Abstract The illumination problem in mathematics questions the existence of a bounded region in which light rays from a point light source do not illuminate the whole region.Since Penrose disproved the illumination problem with elliptical reflective boundaries, the interest has mostly remained in ray optics mainly because there can be no completely

Drought management frameworks are dependent on methods for monitoring and prediction, but quantifying the hazard alone is arguably not sufficient; the negative consequences that may arise from a lack of precipitation must also be Jaw hair clip predicted if droughts are to be better managed.However, the link between drought intensity, expressed by s

The increasing requirements to further reduce pollutant emissions, particularly with regard to the upcoming Euro 7 (EU7) legislation, cause further technical and economic challenges for the development of internal combustion engines.All the emission reduction technologies lead to an increasing complexity not only of the hardware, but also of the co

This article demonstrates the medicinal usage of ginseng in the West from 1660 to 1914.Asian[Korea] ginseng was first introduced into England in the early 17th century, Tanks and North American ginseng was found in the early 18th century.Starting from the late 17th century doctors prescribed ginseng to cure many different kinds of ailments and dise