Granular rheology refers to the continuum mechanical description of granular materials. Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Bouillon is also available in granular, powdered, or liquid form. It may occur as fibrous, granular, lamellar, or compact. Typical treatment processes consist of grates, coagulation, flocculation, sedimentation, granular filtration and disinfection. It is sold in filamentous, granular, or powdered forms. The equations included here describe sediment transport for clastic, or granular sediment. Mill scale can be used as a raw material in granular refractory. They are often used for liquids and granular materials. GAC can be either in granular or extruded form. This model is often used to model concrete, soil or granular materials. The cyst may or may not contain granular and keratinaceous cellular debris. Backwashing of granular media filters involves several steps. An avalanche is an example of a gravity current consisting of granular material. The discrete element method, used for simulating granular materials, is related to SPH.