Abstract: In at least some embodiments, the present invention relates to an air cleaner having a housing portion, and a low profile rain cover having an opening on an underside of the cover to allow unfiltered air to enter into the air cleaner. Also, in at least some embodiments, the present invention relates to an air cleaner including a housing and an additional component by which the air cleaner is capable of being directly coupled to a carburetor inlet. In some such embodiments, one or more protrusions can be provided within a channel formed by the housing/additional component to influence air flow. Further, in at least some embodiments, the present invention relates to an air cleaner having a shaped wall formed on a housing portion, where the shaped wall includes both an interior surface and an exterior surface by which air flowing within the air cleaner is imparted with helical motion.

Abstract: A method of growing a silicon carbide single crystal on a silicon carbide seed crystal in an inert gas environment includes the step of raising the seed crystal temperature to a growth temperature Tseed and raising the temperature of source material to a growth temperature Tsource that is lower than Tseed to define a thermal gradient therebetween. The process also requires maintaining constant seed temperature and constant source temperature throughout substantially the entire growth period of the single crystal. The growth period begins when the seed crystal and source material reach Tseed and Tsource. Another step requires changing only the pressure of the inert gas during the growth period to control the growth rate of the crystal rather than changing any temperatures to control the growth rate once growth of the single crystal has started.