Search results
Results from the WOW.Com Content Network
Hydrox, a gas mixture of hydrogen and oxygen, is occasionally used as an experimental breathing gas in very deep diving. [ 1 ] [ 2 ] It allows divers to descend several hundred metres. [ 3 ] [ 4 ] [ 5 ] Hydrox has been used experimentally in surface supplied, saturation, and scuba diving, both on open circuit and with closed circuit rebreathers.
Treatment gas with oxygen partial pressure of up to 2.5 atm may be administered by BIBS mask for periods of 20 minutes, with breaks of 5 minutes on chamber gas during recompression and holding periods. Pure oxygen may be used at pressures less than 60 fsw. Use: For treatment of serious decompression sickness resulting from upward excursion. [3]
A breathing gas is a mixture of gaseous chemical elements and compounds used for respiration. Air is the most common and only natural breathing gas. Other mixtures of gases, or pure oxygen, are also used in breathing equipment and enclosed habitats such as scuba equipment, surface supplied diving equipment, recompression chambers, high-altitude mountaineering, high-flying aircraft, submarines ...
Lowering the oxygen content of a breathing gas mixture increases the maximum operating depth and duration of the dive before which oxygen toxicity becomes a limiting factor. Most trimix divers limit their working oxygen partial pressure [PO 2 ] to 1.4 bar and may reduce the P O 2 further to 1.3 bar or 1.2 bar depending on the depth, the ...
During extended diving operations very large amounts of breathing gas are used. Helium is an expensive gas and can be difficult to source and supply to offshore vessels in some parts of the world. A closed circuit gas reclaim system can save around 80% of gas costs by recovering about 90% of the helium based breathing mixture.
Gas blending for scuba diving (or gas mixing) is the filling of diving cylinders with non-air breathing gases such as nitrox, trimix and heliox. Use of these gases is generally intended to improve overall safety of the planned dive, by reducing the risk of decompression sickness and/or nitrogen narcosis , and may improve ease of breathing .
The third gas in trimix is nitrogen and the third gas in hydreliox is hydrogen. Because hydrogen is the lightest gas, it is easier to breathe than nitrogen under high pressure. To avoid the risk of explosion, as a rule of thumb hydrogen is only considered for use in breathing mixtures if the proportion of oxygen in the mixture is less than 5%.
The normal relaxed state of the lung and chest is partially empty. Further exhalation requires muscular work. Inhalation is an active process requiring work. [4] Some of this work is to overcome frictional resistance to flow, and part is used to deform elastic tissues, and is stored as potential energy, which is recovered during the passive process of exhalation, Tidal breathing is breathing ...