Abstract: Disclosed is a sorbent for the removal of mercury from combustion flue gas and a preparation method thereof. The sorbent includes an activated heavy oil heavy ash impregnated with 0.1-30% by weight of any chemical substance selected from sulfur, iodine, bromine and chlorine. The sorbent is prepared in an economical manner using heavy oil fly ash, industrial waste generated from heavy oil-fired boilers, and has excellent sorption performance for mercury, so that a low concentration of mercury contained in combustion flue gas discharged from large-scale boilers can be removed by injection of a small amount of the sorbent. Thus, the invention can prevent a reduction in the recycling rate of coal fly ash in coal-fired power plants and minimize operation cost.

Abstract: A binary type diffractive optical element for scalar optics uses a composite artificial material comprising, in a first portion Ma1, microstructures according to a first geometry for which the effective index decreases with the fill factor and, in a second portion Ma2, microstructures according to a second geometry for which the effective index increases with the fill factor. In one example, a composite artificial material is thus formed by hole type microstructures over a first portion, the smallest hole giving the maximum effective index value of said composite artificial material, and pillar type microstructures, the smallest pillar giving the minimum effective index value of said composite artificial material.