Heat transfer always occurs from a region of high temperature to another region of lower temperature. Heat transfer changes the internal energy of both systems involved according to the First Law of Thermodynamics.
Cyperus esculentus (also called chufa sedge, nut grass, yellow nutsedge, tiger nut sedge, or earth almond) is a crop of the sedge family widespread across much of the world.It is native to most of the Western Hemisphere as well as southern Europe, Africa, Madagascar, the Middle East and the Indian Subcontinent.n Spain, C. esculentus is cultivated for its edible tubers, called earth almonds or tiger nuts, for the preparation of  horchata de chufa, a sweet, milk-like beverage. However, in most other countries, C. esculentus is considered a weed.
This tree originated in southern China and Taiwan, but is now a common cultivated tree in northern Thailand, Laos and Vietnam, and mountainous regions of Malaysia and Indonesia, parts of Burma. The thin shelled black seeds, one or two to an orange-red pod, are about 3/4 inch long. The kernel inside is yellow in color.