With some exceptions, an Employee is covered by the HCSO if the Employee works for an Employer covered by the HCSO and: 1  Is entitled to be paid the minimum wage; 2  Has been employed by the Employer for at least 90 calendar days; and. 3  Works at least 8 hours per week in San Francisco.
Vortex ring. Spark photography image of a vortex ring in flight. A vortex ring, also called a toroidal vortex, is a torus-shaped vortex in a fluid or gas; that is, a region where the fluid mostly spins around an imaginary axis line that forms a closed loop. The dominant flow in a vortex ring is said to be toroidal, more precisely poloidal.
Best Answer: a vortex of a tornado is usually referred as devil eye or you can also call it the eye of the tornado. The vortex of a tornado is the area that the tornado revolves around. It is sometimes called the eye of the tornado. The center is very calm and has lower pressure than the surrounding area. Source(s): Geography Course....