Convection is of two types: natural and forced. Heated air rising is an example of natural convection. Hot air has a lower density than that of the cooler air in the atmosphere above it and therefore is buoyant; as it rises, however, it loses energy and cools.
Your best good carbs sources are from this healthy carbohydrates list: 1  Raw and lightly steamed vegetables, 2  Legumes, beans, nuts and seeds, 3  High fiber 100% whole grains,4  Raw, whole, fresh fruits, 5  Most low fat dairy.our best good carbs sources are from this healthy carbohydrates list: 1  Raw and lightly steamed vegetables, 2  Legumes, beans, nuts and seeds, 3  High fiber 100% whole grains,
Carbohydrates are widespread in our food. Exceptions are meat and fish, which have no carbohydrate, and pure fats, such as vegetable oils. Plant foods are our primary source of carbohydrate, and some, such as grains, are the most concentrated. The best carbohydrate foods are unprocessed whole foods, like fresh fruit, 100% juice, whole grains, foods made with whole grains and many vegetables. These foods also contain fiber, vitamins, minerals and antioxidants. Foods made with refined grains have fewer of these nutrients.