A gear that has the teeth cut at an angle to the center line of the gear. This kind of gear is useful because there is no chance of intermittent tooth-to-tooth operation because there are at least two teeth engaged at any time. also helical gear tend to operate quieter than straight-cut gears.
As defined by the Nuclear Regulatory Commission: "Radioactive materials at the end of a useful life cycle that should be properly disposed of, including The highly radioactive material resulting from the reprocessing of spent nuclear fuel, including liquid waste directly in reprocessing and any solid material derived from such liquid waste that contains fission products in concentrations; Irradiated reactor fuel; and Other highly radioactive material that the Commission, consistent with existing law, determines by rule require permanent isolation. High-level waste (HLW) is primarily in the form of spent fuel discharged from commercial nuclear power reactors. It also includes HLW from activities and a small quantity of reprocessed commercial HLW"
A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. It may be manually operated, electrically or pneumatically driven and may use chain, fiber or wire rope as its lifting medium. The load is attached to the hoist by means of a lifting hook.
A hoist may also be part of a crane.