Butyl rubber and EPDM (ethylene propylene diene monomer - a synthetic rubber) are the two best flexible liners for water garden construction. Each of these materials is UV stable and should last 20 years or more. EPDM and butyl rubber are generally available in 45 mil and 60- or 30-mil thicknesses, respectively.
human behavior. The capacity of mental, physical, emotional, and social activities experienced during the five stages of a human being's life-prenatal, infancy, childhood, adolescence, and adulthood.
Psychology Definition of BEHAVIOR: n. an action, activity, or process which can be observed and measured. Often, these actions, activities, and processes are initiated in response to stimuli which are either internal or external. The results of studies on these must be objective, however, in order to be reliable and valid for scientific purposes. See behaviorism.