Oil paint very slowly, darken, and crack, unlike mastic and wax (the latter of which was used in encaustic painting). Greek writers such as Aetius Amidenus recorded recipes involving the use of oils for drying, such as walnut, poppy, hempseed, pine nut, castor, and linseed. When thickened, the oils became resinous and could be used as varnish to seal and protect paintings from water. Additionally, when yellow pigment was added to oil, it could be spread over tin foil as a less expensive alternative to gold leaf. Early Christian monks maintained these records and used the techniques in their own artworks. Theophilus
Gas oil separation plant Gas oil separation plant A Gas-oil separation package (GOSP) is a "package" used in the upstream oil industry. The package is fitted the well head after the choke valve and before the production manifold, and separates the crude oil from sediments, solids and sand (below using a filter) and gases and condensates to allow the crude to be pumped on the pipeline. Beware that water need not be separated, causing the need to add chemicals so that the crude and water emulsifies. This process is then reversed at storage by adding demulsifiers that makes the water fall out, and can