Containment wind forces

The concept of air as a colloid and the term aerosol for air containing an assembly of suspended particles were originally introduced by Schmauss and Wigand (1929). Colloids are inherently stable because fine particles are subject to Brownian motion and resist settling by sedimentation. The individual aerosol particles may be solid, liquid, or of a mixed variety, and all types are found in the atmosphere. Solid particles in the air are called dust. They are primarily formed by the erosion of minerals at the earth surface and enter the atmosphere by wind force. Sea spray from the ocean surface provides a prolific source of liquid droplets, which upon evaporation produce sea-salt crystals or a concentrated aqueous solution thereof. Solid and liquid particles also arise from the condensation of vapors when the vapor pressure exceeds the saturation point. For example, smoke from the open and often incomplete combustion of wood or agricultural refuse arises at least in part from the condensation of organic vapors. 

The use of wind as a renewable energy source involves the conversion of power contained in moving air masses to rotating shaft power. These air masses represent the complex circulation of winds near the surface of Earth caused by Earth s rotation and by convective heating from the sun. The actual conversion process utilizes basic aerodynamic forces, ie, lift or drag, to produce a net positive torque on a rotating shaft, resulting in the production of mechanical power, which can then be used directly or converted to electrical power. 

A boom s performance and its ability to contain oil are affected by water currents, waves, and winds. Either alone or in combination, these forces often lead to boom failure and loss of oil. Eight common ways in which booms fail are discussed here. Some of these are illustrated in Figure 17. 

Tension member — The part of a floating oil containment boom that carries the load placed on the barrier by wind, wave, and current forces. Tension members are commonly made of wire cable or chain due to their strength and stretch resistance. 

Conventional polypropylene is an appropriate container material for cylindrical VRLA cells because the necessary contact force for the glass-mat separator is supplied by the winding and maintained by a tensile force in the cell wall. Regardless of the nominal voltage, and therefore the number of cells, prismatic VRLA batteries require a reinforced plastic for the container and the lid to provide an AGM contact force and to keep the active-material compressed [42-44]. 

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