TopRq.com

A POTD is an acronym for "Photo of the Day", "Picture of the Day", "Post of the Day" or "Poll of the Day". It is a term most commonly used by online digital photography communities as an honor to outstanding photos that are selected daily from among that community's membership. They can either be tagged as POTD or displayed in a special page on that site...

A 2D geometric model is a geometric model an object as two-dimensional figure, usually on the Euclidean or Cartesian plane. Even though all material objects are three-dimensional, a 2D geometric model is ten adequate for certain flat objects, such as paper cut-outs and machine parts made sheet metal. 2D geometric models are also convenient for describing certain types artificial images, such as technical diagrams, logos, the glyphs a font, etc...

Freezing or solidification is a phase change in which a liquid turns into a solid when its temperature is lowered below its freezing point. The reverse process is melting. All known liquids, except liquid helium, freeze when the temperature is lowered enough. Liquid helium remains liquid at atmospheric pressure even at absolute zero, and can only be solidified under pressure...