In a method of forming an ohmic layer of a DRAM device, the metal silicide layer between the storage node contact plug and the lower electrode of a capacitor is formed as the ohmic layer by a first heat treatment under a first temperature and an instantaneous second heat treatment under a second temperature higher than the first temperature. A heat dissipating element may be coupled to the primary material. A method for inactivating alternately at least two biosynthetic pathways in a methylotrophic yeast is provided. Each projection includes a portion located higher than a center line of the unfiltered primary profile curve and having a shape selected from a generally trapezoidal shape with rounded corners, a generally crowning shape, a generally elliptic arc shape, a generally sinusoidal shape and a generally triangular shape with a rounded apex. The tip sections are radially disposed in a fan tip duct.