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.
In order to deal with this anxiety, Freud believed that defense mechanisms helped shield the ego from the conflicts created by the id, superego, and reality. Most notably used by Sigmund Freud in his psychoanalytic theory, a defense mechanism is a tactic developed by the ego to protect against anxiety. Defense mechanisms are thought to safeguard the mind against feelings and thoughts that are too difficult for the conscious mind to cope with.