Braeburn of sweet and tart flavour. They are available October through April in the northern hemisphere and are medium to large in size. They are a popular fruit for growers because of their ability to store well when chilled. Braeburn apples are useful in cooking in that they hold their shape and do not release a great deal of liquid making them ideal for tarts. According to the US Apple Association website it is one of the fifteen most popular apple cultivars in the United States. Apples can be preserved by short, medium or long-term storage. Braeburn can turn brown inside
Algebraic variety algebraic sets. Using the Nullstellensatz and related results, mathematicians have established a strong correspondence between questions on algebraic sets and questions of ring theory. This correspondence is a defining feature of algebraic geometry. An "affine variety" over an algebraically closed field is conceptually the easiest type of variety to define, which will be done in this section. Next, one can define projective and quasi-projective varieties in a similar way. The most general definition of a variety is obtained by patching together smaller quasi-projective varieties. It is not obvious that one can construct genuinely new examples of varieties in this way,