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,
Grain Products. Grain products are the leading source of carbohydrates in the American diet. Grains naturally contain high concentrations of starch, which your gastrointestinal system breaks down into sugars. Common grains in the U.S. diet include wheat, oats, rice, barley and cornmeal.