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Lime Plaster
Lime plaster is a type of plaster composed of sand, water, and lime, usually non-hydraulic hydrated lime (also known as slaked lime, high calcium lime or air lime). Ancient lime plaster often contained horse hair for reinforcement and pozzolan additives to reduce the working time. Traditional non-hydraulic hydrated lime only sets through carbonatation when the plaster is kept moist and access of CO2 from the air is possible. It will not set when submersed in water. When a very thick layer or several layers are applied, the lime can remain soft for weeks. The curing time of lime plaster can be shortened by using (natural) hydraulic lime or adding pozzolan additives, transforming it into artificially hydraulic lime. In ancient times, Roman lime plaster incorporated pozzolanic volcanic ash; in modern times, fly ash is preferred. Non-hydraulic lime plaster can also be made to set faster by adding gypsum. Lime production for use in plastering home-made cisterns (in making them ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plaster - Putz In Pompeji
Plaster is a building material used for the protective or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of buildings, while "render" commonly refers to external applications. Another imprecise term used for the material is stucco, which is also often used for plasterwork that is worked in some way to produce relief decoration, rather than flat surfaces. The most common types of plaster mainly contain either gypsum, lime, or cement,Franz Wirsching "Calcium Sulfate" in Ullmann's Encyclopedia of Industrial Chemistry, 2012 Wiley-VCH, Weinheim. but all work in a similar way. The plaster is manufactured as a dry powder and is mixed with water to form a stiff but workable paste immediately before it is applied to the surface. The reaction with water liberates heat through crystallization and the hydrated plaster then hardens. Plaster can be relatively easily worked wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffusion
Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical potential. It is possible to diffuse "uphill" from a region of lower concentration to a region of higher concentration, like in spinodal decomposition. The concept of diffusion is widely used in many fields, including physics (particle diffusion), chemistry, biology, sociology, economics, and finance (diffusion of people, ideas, and price values). The central idea of diffusion, however, is common to all of these: a substance or collection undergoing diffusion spreads out from a point or location at which there is a higher concentration of that substance or collection. A gradient is the change in the value of a quantity, for example, concentration, pressure, or temperature with the change in another variable, usually distance. A change in c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akhenaten
Akhenaten (pronounced ), also spelled Echnaton, Akhenaton, ( egy, ꜣḫ-n-jtn ''ʾŪḫə-nə-yātəy'', , meaning "Effective for the Aten"), was an ancient Egyptian pharaoh reigning or 1351–1334 BC, the tenth ruler of the Eighteenth Dynasty. Before the fifth year of his reign, he was known as Amenhotep IV ( egy, jmn-ḥtp, links=no, meaning "Amun is satisfied", Hellenized as ''Amenophis IV''). As a pharaoh, Akhenaten is noted for abandoning Egypt's traditional polytheism and introducing Atenism, or worship centered around Aten. The views of Egyptologists differ as to whether the religious policy was absolutely monotheistic, or whether it was monolatry, syncretistic, or henotheistic. This culture shift away from traditional religion was reversed after his death. Akhenaten's monuments were dismantled and hidden, his statues were destroyed, and his name excluded from lists of rulers compiled by later pharaohs. Traditional religious practice was gradually restored, not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
