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Dissolved oxygen levels required by various species in the Chesapeake Bay (US). In aquatic environments, oxygen saturation is a ratio of the concentration of "dissolved oxygen" (DO, O 2), to the maximum amount of oxygen that will dissolve in that water body, at the temperature and pressure which constitute stable equilibrium conditions.
Oxygen concentration may refer to: What oxygen concentrators do - increase the fraction of oxygen in a gas mixture; Oxygen saturation, the fraction of oxygen dissolved in or carried by a fluid; Limiting oxygen concentration, the concentration below which combustion can not take place
These devices use nearly pure oxygen at about one-third normal pressure, resulting in a normal blood partial pressure of O 2. This trade-off of higher oxygen concentration for lower pressure is needed to maintain suit flexibility. [117] [118] Scuba and surface-supplied underwater divers and submarines also rely on artificially delivered O 2.
Air is typically around 21% oxygen, and at sea level, the PO 2 of air is typically around 159 mmHg. [2] Humidity dilutes the concentration of oxygen in air. As air is inhaled into the lungs, it mixes with water and exhaust gasses including CO 2, further diluting the oxygen concentration and lowering the PO 2.
Oxygen equivalent compares the relative amount of oxygen available for respiration at a variable pressure to that available at SATP.As external respiration depends on the exchange of gases due to partial pressures across a semipermeable membrane and normally occurs at SATP, an oxygen equivalent may aid in recognizing and managing variable oxygen availability during procedures such as ...
At current rates of primary production, today's concentration of oxygen could be produced by photosynthetic organisms in 2,000 years. [4] In the absence of plants, the rate of oxygen production by photosynthesis was slower in the Precambrian, and the concentrations of O 2 attained were less than 10% of today's and probably fluctuated greatly.
The consumption of oxygen by microbes and plant roots, and their release of carbon dioxide, decreases oxygen and increases carbon dioxide concentration. Atmospheric CO 2 concentration is 0.04%, but in the soil pore space it may range from 10 to 100 times that level, thus potentially contributing to the inhibition of root respiration. [66]
Atmospheric chemistry is a branch of atmospheric science that studies the chemistry of the Earth's atmosphere and that of other planets. This multidisciplinary approach of research draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and volcanology, climatology and other disciplines to understand both natural and human-induced changes in atmospheric ...