Editing Granular convection (section)

===Manufacturing===
[[File:Raisin Bran Cereal in box (38390064056).jpg|alt=Raisins and bran flakes, inside a cereal box.  Multiple raisins are visible on top of the flakes|thumb|This phenomenon results in [[Raisin|raisins]] tending to rise to the top of a box of [[breakfast cereal]], so that the first servings of the cereal contain more raisins than usual, and only flakes are left at the bottom of the box.]]

The effect is of interest to food manufacturing and similar operations.<ref name=":0" /> Once a homogeneous mixture of granular materials has been produced, it is usually undesirable for the different particle types to segregate.  Several factors determine the severity of the Brazil nut effect, including the sizes and [[density|densities]] of the particles, the [[pressure]] of any [[gas]] between the particles, and the shape of the container. A rectangular box (such as a box of [[breakfast cereal]]) or [[cylinder (geometry)|cylinder]] (such as a can of nuts) works well to favour the effect,{{Citation needed|date=February 2008}} while a container with outwardly slanting walls (such as in a conical or spherical geometry) results in what is known as the '''reverse Brazil nut effect'''.<ref>{{Cite journal|last1=Knight|first1=James B.|last2=Jaeger|first2=H. M.|last3=Nagel|first3=Sidney R.|date=1993-06-14|title=Vibration-induced size separation in granular media: The convection connection|journal=Physical Review Letters|language=en|volume=70|issue=24|pages=3728–3731|doi=10.1103/PhysRevLett.70.3728|pmid=10053947|bibcode=1993PhRvL..70.3728K|issn=0031-9007}}</ref>