Capturing hood. A hood positioned as close to a dust source as possible to capture the dust-laden air and pull it into an exhaust ventilation system. Carryback. Material that sticks or clings to a conveyor belt after passing over the head pulley. Cartridge collector. In dust collection systems, a type of collector that captures particulate from a gas stream by forcing the gas through filter elements, which are arranged in a pleated configuration. Centrifugal collector. In dust collection systems, a device that separates particulate from the air by centrifugal force. Also called a cyclone. Centrifugal fan. A fan in which the airflow is drawn into the rotating impeller and discharged radially from the fan blade into the housing. Centrifugal fans include radial, backward, and forward blade type. Chimney effect. The behavior of heated air or gas rising in a vertical passage, as in a chimney, due to its lower density compared to the surrounding air or gas. Chronic silicosis. A slowly progressive, nodular form of silicosis that typically develops after 10-30 years of exposures to respirable crystalline silica dust. Coanda effect. The tendency of a moving fluid to be attracted to a nearby surface. Collaring. The preliminary step in drilling, forming the beginning of a drill hole, or collar. Contact angle. The angle at which a liquid meets a solid surface. Control efficiency. A metric usually expressed as a percentage used to compare the results of two or more outcomes. Crown. The mid-point of a road raised such that water drains off either side of the road surface into a ditch. In cross-section, the shape of the road is depicted as an A-shape, with the highest point in the center of the road. Cure. The hardening of a chemical additive and base material. Cuttings. Material that is produced during the drilling process. Cuttings are usually a fine-sized material. Cyclone. In dust collection systems, a conical device that uses centrifugal force to separate large-and small-diameter particles. Deliquescent. The ability of a material to absorb moisture from the air and become liquid. Depth loading. In dust collection systems, a method of collecting particulate on a fabric by maintaining a filter cake on the fabric to optimize collection efficiency. When depth loading is used on a particular fabric, dust is intentionally allowed to penetrate into the fabric to form a layer of dust on the bag.