This is usually defined as the act of replacing stale or noxious air with fresh air.
In the eco field it is also important to differentiate between what are termed passive ventilation and active ventilation. Passive ventilation is where no additional electrical or mechanical energy is required to make the ventilation work. Active ventilation on the other hand won't work without using additional energy.
Passive ventilation is an aspect of passive building design and often utilizes heat chimneys and natural air flows across the land to achieve adequate ventilation.
A wind generator design where the rotating shaft is perpendicular to the ground, and the cups or blades rotate parallel to the ground.
Search the Web for Vertical Axis Wind TurbineA wind turbine with the axis or main shaft mounted vertically, or perpendicular to the earth's surface. This type of turbine does not need to be turned to face the wind - the wind always blows across it. Types include Savonius and Darrius.
Search the Web for Vertical-axis Wind TurbineVirgin paper is paper that contains no recycled content and is made directly from the pulp of trees or, alternatively, cotton.