Sunspots are magnetic in nature. They are the places (active regions) where the Sun's magnetic field rises up from below the Sun's surface and those magnetic regions poke through. Sunspots are darker than the surrounding areas because they are expending less energy and have a lower temperature. Sunspots often have poles (polarity) like the south and north poles of magnets. Sunspots are formed continuously as the Sun's magnetic field actively moves through the Sun. The sunspots have lifetimes of days or perhaps one week or a few weeks. Here is one scenario that some scientists think explains how sunspots form.
Freebase(0.00 / 0 votes)Rate this definition: Non-refoulement is a principle of international law which forbids the rendering of a true victim of persecution to their persecutor. Generally the persecutor in mind is a state actor. It is a principle of both the customary and trucial law of nations.
Non-sanded grout is a cement based grout normally used on smaller tile joints. It is recommended in floor and wall tiling projects with grout joints spacing between 1/16th to 1/8th inch. When non-sanded grout is used to fill wider joints, the grout could possibly crack due to the lack of bonding that the sands provide. This grout is designed for use in tile surfaces that are dry when the grout is applied. The water retentive additive allows the grout to stay moist until the cement cures properly.