S Your new gas furnace may have been installed in one of two. ways, as a direct-vent (2-pipe-Fig. 2) application or as a. non-direct vent (1-pipe-Fig. 3) application. S In a direct-vent (2-pipe) application,your furnace uses air. from outside the home for combustion and ventsflue gas to the. outdoors.
For the biological concept, see Anti-predator adaptation. A defence mechanism is an unconscious psychological mechanism that reduces anxiety arising from unacceptable or potentially harmful stimuli. Sigmund Freud was one of the first proponents of this construct.
They continue to exert a powerful influence on behavior. The forces, which try to keep painful or socially undesirable thoughts and memories out of the conscious mind, are termed defense mechanisms. There is a perpetual battle between the wish (repressed into the id) and the defense mechanisms. We use defense mechanisms to protect ourselves from feelings of anxiety or guilt, which arise because we feel threatened, or because our id or superego becomes too demanding.