Mercury (element) and galinstan alloy thermometers are also an option. Mercury thermometers are still occasionally used in the medical field because they are more accurate than alcohol thermometers, though both are commonly being replaced by electronic thermometers and less commonly by galinstan thermometers. Mercury thermometers are still widely used for certain scientific applications because of their greater accuracy and working range. Historically, one of the largest releases was from the Colex plant, a lithium-isotope separation plant at Oak Ridge, Tennessee. The plant operated in the 1950s and 1960s. Records are incomplete and unclear, but government commissions have estimated that some two million
Active safety events in a favourable manner. In the automotive sector the term active safety (or primary safety) refers to safety systems that are active "prior" to an accident. This has traditionally referred to non-complex systems such as good visibility from the vehicle and low interior noise levels. Nowadays, however, this area contains highly advanced systems such as anti-lock braking system, electronic stability control and collision warning/avoidance through automatic braking. This compares with passive safety (or secondary safety), which are active "during" an accident. To this category belong seat belts, deformation zones and air-bags, etc. Advancement in passive safety systems has progressed