In DSM, nicotine dependence is included under the general definition of substance dependence.  The essential feature of Substance Dependence is a cluster of cognitive, behavioral, and physiologic symptoms indicating that the individual continues use of the substance despite significant substance-related problems.
The Best Materials to Cover your Greenhouse. 1  Glass: The traditional greenhouse covering, glass is the preferred material for permanence. 2  Film Plastic: Film plastic is one sixth to one tenth of the cost per square foot of a glass covered structure.
Strong, reliable, and maybe not so green. Concrete is the default material for basement slabs, but the cement that's used as the binder in concrete is a significant source of greenhouse gas emissions. That has one reader wondering about other options.