query: Who discovered oxygen?

title: Oxygen bar

text: Oxygen bar An oxygen bar is an establishment, or part of one, that sells oxygen for recreational use. Individual flavored scents may be added to enhance the experience. The flavors in an oxygen bar come from bubbling oxygen through bottles containing aromatic solutions before it reaches the nostrils: most bars use food-grade particles to produce the scent, but some bars use aroma oils. In 1776, Thomas Henry, an apothecary and Fellow of the Royal Society of England speculated tongue in cheek that Joseph Priestley’s newly discovered dephlogisticated air (now called oxygen) might become “as fashionable as French wine at the

title: Oxygen

text: part of air which is required for life, lends sufficient weight to the discovery of oxygen by Sendivogius. This discovery of Sendivogius was however frequently denied by the generations of scientists and chemists which succeeded him. It is also commonly claimed that oxygen was first discovered by Swedish pharmacist Carl Wilhelm Scheele. He had produced oxygen gas by heating mercuric oxide and various nitrates in 1771–2. Scheele called the gas "fire air" because it was then the only known agent to support combustion. He wrote an account of this discovery in a manuscript titled "Treatise on Air and Fire", which

title: Oxygen

text: air without being continuously replenished by the photosynthetic action of living organisms. Another form (allotrope) of oxygen, ozone (), strongly absorbs ultraviolet UVB radiation and the high-altitude ozone layer helps protect the biosphere from ultraviolet radiation. However, ozone present at the surface is a byproduct of smog and thus a pollutant. Oxygen was isolated by Michael Sendivogius before 1604, but it is commonly believed that the element was discovered independently by Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, and Joseph Priestley in Wiltshire, in 1774. Priority is often given for Priestley because his work was published first. Priestley,

title: Oxygen (Doctor Who)

text: mildly criticizing it for lack of novelty, articulating his "struggle with the central conceit that in the future, in space, oxygen will be a commodity that you pay for dearly, even with your life." He also noted how the episode borrowed themes from other fictional films, such as "Gravity" (2013) and "Alien" (1979), as well as themes from previous episodes of the programme. Oxygen (Doctor Who) "Oxygen" is the fifth episode of the tenth series of the British science fiction television series "Doctor Who". It is written by Jamie Mathieson and was broadcast on 13 May 2017 on BBC One.

title: Oxygen (Doctor Who)

text: Oxygen (Doctor Who) "Oxygen" is the fifth episode of the tenth series of the British science fiction television series "Doctor Who". It is written by Jamie Mathieson and was broadcast on 13 May 2017 on BBC One. "Oxygen" received highly positive reviews from critics, most commenting on the overlying themes of the episode and the aspect of capitalism. The Doctor (Peter Capaldi), Bill Potts (Pearl Mackie) and Nardole (Matt Lucas) investigate a space station after receiving a distress call sent by them, but find that the station is infested with a crew of walking dead. The trio need to base

title: Oxygen (Doctor Who)

text: their plans on how much oxygen they have left, when they find themselves in a situation of no hope. The Doctor, Bill and an angry Nardole travel in the TARDIS to follow a distress call to a deep-space mining station. When the TARDIS is jettisoned by the station's computers, the trio are forced to wear "smartsuits", robotic spacesuits capable of independent operation tied to the station. The suits are also the only source of oxygen, as the mining company does not provide an oxygen atmosphere inside the station, and every activity is measured in breaths. The surviving crew warn them

title: Oxygen (Doctor Who)

text: episode received 5.27 million views overall, and it received an Appreciation Index score of 83. "Oxygen" received acclaim from critics. It currently holds a score of 100% on Rotten Tomatoes. Zoe Delahunty-Light of "SFX Magazine" gave the episode a rating of 4.5 stars out of 5, complimenting the idea of oxygen becoming a limited resource, and how the idea related to every plot point of the episode, rather than being an excuse for the tense situations. She also praised Pearl Mackie's portrayal of Bill in the episode, Mackie's acting being "consistently honest, raw at times, and never, ever whimsy", and

title: Oxygen (Doctor Who)

text: from 1966 to 1969. The Doctor quotes 1 Corinthians 15:55 when he says "Death, where is thy sting?" The read-through for "Oxygen" took place on 12 October 2016. The episode was filmed as part of the fourth production block alongside the tenth episode of the series, "The Eaters of Light". Shooting began on 17 October and ended on 18 November 2016. In his newsletter, Jamie Mathieson revealed that "Oxygen" was originally intended as a prequel to his 2014 episode "Mummy on the Orient Express". In earlier drafts, Kline, a corporate representative, appears on a monitor to offer the characters promotions

title: Solid oxygen

text: strong infrared absorption, and a magnetic collapse. It is also stable over a very large pressure domain and has been the subject of numerous X-ray diffraction, spectroscopic and theoretical studies. It has been shown to have a monoclinic C2/m symmetry and its infrared absorption behaviour was attributed to the association of oxygen molecules into larger units. A ζ-phase appears at 96 GPa when ε-phase oxygen is further compressed. This phase was discovered in 1990 by pressurizing oxygen to 132 GPa. The ζ-phase with metallic cluster exhibits superconductivity at pressures over 100GPa and a temperature below 0.6K. Solid oxygen Solid oxygen

title: Alpha-oxygen

text: discovered and named in 1990 by researchers from the Boreskov Institute of Catalysis in the ZSM-5 zeolite, and was later described in detail by researchers from Stanford University and KU Leuven in the beta zeolite. Alpha-oxygen Alpha-oxygen (α-O) is a reactive oxygen species formed from an oxygen-atom abstraction (OAT) from nitrous oxide (NO) by alpha-Iron (α-Fe) catalysts. The latter is defined as a high spin (S=2) divalent Iron(II) ion in a constrained square planar coordination with an accessible axial coordination position. The stabilization of α-O requires structural strain on the equatorial ligand field to maintain the reactive oxygen atom in

title: Oxygen

text: A metallic phase was discovered in 1990 when solid oxygen is subjected to a pressure of above 96 GPa and it was shown in 1998 that at very low temperatures, this phase becomes superconducting. Oxygen dissolves more readily in water than nitrogen, and in freshwater more readily than seawater. Water in equilibrium with air contains approximately 1 molecule of dissolved for every 2 molecules of (1:2), compared with an atmospheric ratio of approximately 1:4. The solubility of oxygen in water is temperature-dependent, and about twice as much (14.6 mg·L) dissolves at 0 °C than at 20 °C (7.6 mg·L). At

title: Oxygen (Doctor Who)

text: he'd thought that they should have. Ross Ruediger of New York Magazine wrote a positive review, giving the episode 4 stars of 5. He praised the writer for his mature script, stating that "Jamie Mathieson writes great, thought-provoking "Doctor Who "episodes and "Oxygen" is no exception." He then went on to compliment the production values, expressing his view that the production team delivered amazing imagery to complement the intense script of the episode. Patrick Mulkern of Radio Times gave the episode 3 out of 5 stars, praising the story for its truthfulness to the fundamental themes of the show, but

title: Oxygen cycle

text: The tiny marine cyanobacterium Prochlorococcus was discovered in 1986 and accounts for more than half of the photosynthesis of the open ocean. An additional source of atmospheric free oxygen comes from photolysis, whereby high-energy ultraviolet radiation breaks down atmospheric water and nitrous oxide into component atoms. The free H and escape into space, leaving O in the atmosphere: The main way free oxygen is lost from the atmosphere is via respiration and decay, mechanisms in which animal life and bacteria consume oxygen and release carbon dioxide. The lithosphere also consumes atmospheric free oxygen by chemical weathering and surface reactions. An

title: Compounds of oxygen

text: octadecamolybdophosphoric acid (). One unexpected oxygen compound is dioxygenyl hexafluoroplatinate, , discovered in studying the properties of platinum hexafluoride (). A change in color when this compound was exposed to atmospheric air suggested that dioxygen was being oxidized (in turn the difficulty of oxidizing oxygen led to the hypothesis that xenon might be oxidized by , resulting in discovery of the first xenon compound xenon hexafluoroplatinate ). The cations of oxygen are formed only in the presence of stronger oxidants than oxygen, which limits them to the action of fluorine and certain fluorine compounds. Simple oxygen fluorides are known. Among

title: Oxygen toxicity

text: nervous system toxicity was first described by Paul Bert in 1878. He showed that oxygen was toxic to insects, arachnids, myriapods, molluscs, earthworms, fungi, germinating seeds, birds, and other animals. Central nervous system toxicity may be referred to as the "Paul Bert effect". Pulmonary oxygen toxicity was first described by J. Lorrain Smith in 1899 when he noted central nervous system toxicity and discovered in experiments in mice and birds that had no effect but of oxygen was a pulmonary irritant. Pulmonary toxicity may be referred to as the "Lorrain Smith effect". The first recorded human exposure was undertaken in

title: Oxygen

text: shield for the planet. Near the Earth's surface, it is a pollutant formed as a by-product of automobile exhaust. At low earth orbit altitudes, sufficient atomic oxygen is present to cause corrosion of spacecraft. The metastable molecule tetraoxygen () was discovered in 2001, and was assumed to exist in one of the six phases of solid oxygen. It was proven in 2006 that this phase, created by pressurizing to 20 GPa, is in fact a rhombohedral cluster. This cluster has the potential to be a much more powerful oxidizer than either or and may therefore be used in rocket fuel.

title: Poverty Discovered

text: Poverty Discovered Located Cooksville in Howard County, Maryland, United States, Poverty Discovered, "Summer Hill Farm" "Poverty Discovered" is named after the 1737 acre land tract Given to Joseph Hobbs by Lord Calvert in 1760. It was then owned by Captain Thomas Hobbs, who was involved in the burning of the Peggy Stwewart. He willed the property to his son, Kentucky General Assemblyman Joseph Hobbs Jr. The slave farm was situated on the road to Ellicott's Mills from Hood's Mill. By 1783, "Poverty Discovered" was subdivided and consisted of 400 acres. In November 3, 1793 Henry Howard sold the Poverty Discovered

title: Poverty Discovered

text: as the "Summer Hill Farm" which raises thoroughbred horses for track uses or sale. Neighboring Greenway farms also resides on land once named "Poverty Discovered". In 2012, the resale of the adjacent Woodmont Academy sparked controversy as a high density use of the property next to the historic site. Poverty Discovered Located Cooksville in Howard County, Maryland, United States, Poverty Discovered, "Summer Hill Farm" "Poverty Discovered" is named after the 1737 acre land tract Given to Joseph Hobbs by Lord Calvert in 1760. It was then owned by Captain Thomas Hobbs, who was involved in the burning of the Peggy

title: Oxygen

text: however, called oxygen "dephlogisticated air", and did not recognize it as a chemical element. The name "oxygen" was coined in 1777 by Antoine Lavoisier, who first recognized oxygen as a chemical element and correctly characterized the role it plays in combustion. Common uses of oxygen include production of steel, plastics and textiles, brazing, welding and cutting of steels and other metals, rocket propellant, oxygen therapy, and life support systems in aircraft, submarines, spaceflight and diving. The name "oxygen" was coined in 1777 by Antoine Lavoisier, whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion.

title: Solid oxygen

text: undergoes a dramatic phase transition to a different allotrope. Its volume decreases significantly, and it changes color from sky-blue to deep red. This ε-phase was discovered in 1979, but the structure has been unclear. Based on its infrared absorption spectrum, researchers assumed in 1999 that this phase consists of molecules in a crystal lattice. However, in 2006, it was shown by X-ray crystallography that this stable phase known as ε oxygen or red oxygen is in fact . No one predicted the structure theoretically: a rhomboid cluster consisting of four molecules. In this phase it exhibits a dark-red color, very

title: Oxygen (Doctor Who)

text: self-destruct if they are killed, and convinces the others this is a "good death" and revenge against the corporation. The computers recognise this threat to corporate profits and recalculate the suits' programming, and the zombies turn over their oxygen supplies to the survivors. The Doctor then revives Bill, knowing that her malfunctioning suit did not have enough power to lethally shock her. The TARDIS is recovered, and they drop the survivors off at their head office to confront the company; the Doctor notes there was a successful rebellion six months later. Nardole restores the Doctor's eyes, but when they return

title: Oxygen (Doctor Who)

text: gone blind from the ordeal. The computer discovers their location, but as they flee, Bill's suit again malfunctions and will not move, nor will it allow the others to carry it or release her. The Doctor leaves her behind, assuring her she will not die. She is, however, electrocuted when the zombies touch her. The Doctor reveals the limit of breaths is an algorithm to stop people "wasting" oxygen, part of the company's automated profit-making system; killing the wearers was just the logical endpoint of corporate profit over human life. He hacks the station's systems to cause the station to

title: Oxygen toxicity

text: to establish oxygen exposure limits for habitat operations. Even today, models for the prediction of pulmonary oxygen toxicity do not explain all the results of exposure to high partial pressures of oxygen. Recreational scuba divers commonly breathe nitrox containing up to 40% oxygen, while technical divers use pure oxygen or nitrox containing up to 80% oxygen. Divers who breathe oxygen fractions greater than of air (21%) need to be trained in the dangers of oxygen toxicity and how to prevent them. In order to buy nitrox, a diver has to show evidence of such qualification. Since the late 1990s the

title: Oxygen toxicity

text: oxygen toxicity are patients on mechanical ventilation with exposure to levels of oxygen greater than 50%, and patients exposed to chemicals that increase risk for oxygen toxicity such the chemotherapeutic agent bleomycin. Therefore, current guidelines for patients on mechanical ventilation in intensive care recommends keeping oxygen concentration less than 60%. Likewise, divers who undergo treatment of decompression sickness are at increased risk of oxygen toxicity as treatment entails exposure to long periods of oxygen breathing under hyperbaric conditions, in addition to any oxygen exposure during the dive. Prolonged exposure to high inspired fractions of oxygen causes damage to the retina.

title: Oxygen bar

text: that at one end of the hose is a source of oxygen, so the individual providing the hose and turning on the supply is dispensing a prescription drug. He commented that "Although oxygen bars that dispense oxygen without a prescription violate FDA regulations, the agency applies regulatory discretion to permit the individual state boards of licensing to enforce the requirements pertaining to the dispensing of oxygen." Canadian Society of Respiratory Therapists says that "As health professionals, we cannot ethically or morally support providing oxygen therapy to those who do not require it." Oxygen bar An oxygen bar is an establishment,

title: Oxygen toxicity

text: 2,000 experiments on oxygen toxicity to support the initial use of closed circuit oxygen rebreathers. Naval divers in the early years of oxygen rebreather diving developed a mythology about a monster called "Oxygen Pete", who lurked in the bottom of the Admiralty Experimental Diving Unit "wet pot" (a water-filled hyperbaric chamber) to catch unwary divers. They called having an oxygen toxicity attack "getting a Pete". In the decade following World War II, Lambertsen "et al." made further discoveries on the effects of breathing oxygen under pressure and methods of prevention. Their work on intermittent exposures for extension of oxygen tolerance

title: Oxygen toxicity

text: Oxygen toxicity Oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen () at increased partial pressures. It is also known as oxygen toxicity syndrome, oxygen intoxication, and oxygen poisoning. Severe cases can result in cell damage and death, with effects most often seen in the central nervous system, lungs, and eyes. Historically, the central nervous system condition was called the "Paul Bert effect", and the pulmonary condition the "Lorrain Smith effect", after the researchers who pioneered the discoveries and descriptions in the late 19th century. Oxygen toxicity is a concern for underwater divers, those on

title: Oxygen

text: or decompression at relatively shallow depths (~6 meters depth, or less), or medical treatment in recompression chambers at pressures up to 2.8 bar, where acute oxygen toxicity can be managed without the risk of drowning. Deeper diving requires significant dilution of with other gases, such as nitrogen or helium, to prevent oxygen toxicity. People who climb mountains or fly in non-pressurized fixed-wing aircraft sometimes have supplemental supplies. Pressurized commercial airplanes have an emergency supply of automatically supplied to the passengers in case of cabin depressurization. Sudden cabin pressure loss activates chemical oxygen generators above each seat, causing oxygen masks to

title: Oxygen therapy

text: oxygen therapy is known to have a negative impact on a patient's condition. Oxygen should never be given to a patient who is suffering from paraquat poisoning unless they are suffering from severe respiratory distress or respiratory arrest, as this can increase the toxicity. (Paraquat poisoning is rare – for example 200 deaths globally from 1958 to 1978). Oxygen therapy is not recommended for patients who have suffered pulmonary fibrosis or other lung damage resulting from bleomycin treatment. High levels of oxygen given to infants causes blindness by promoting overgrowth of new blood vessels in the eye obstructing sight. This

title: Oxygen mask

text: parachute. They are often part of a pressure suit or intended for use with a flight helmet. Three main kinds of oxygen masks are used by pilots and crews who fly at high altitudes: continuous flow, diluter demand, and pressure demand. In a "continuous-flow system", oxygen is provided to the user continuously. It does not matter if the user is exhaling or inhaling as oxygen is flowing from the time the system is activated. Below the oxygen mask is a rebreather bag that collects oxygen during exhalation and as a result allows a higher flow rate during the inhalation cycle.

title: Oxygen mask

text: experienced by some patients when wearing an oxygen mask. The vast majority of patients having an operation will at some stage wear an oxygen mask; they may alternatively wear a nasal cannula but oxygen delivered in this way is less accurate and restricted in concentration. Silicone and rubber oxygen masks are heavier than plastic masks. They are designed to provide a good seal for long-duration use by aviators, medical research subjects, and hyperbaric chamber and other patients who require administration of pure oxygen, such as carbon monoxide poisoning and decompression sickness victims. Dr. Arthur H. Bulbulian pioneered the first modern

title: Oxygen therapy

text: case oxygen flow should be moderated to achieve oxygen saturation levels, based on pulse oximetry (with a target level of 94–96% in most, or 88–92% in people with COPD). Excessively use of oxygen in those who are acutely ill however increases the risk of death. In 2018 recommendations within the British Medical Journal were that oxygen should be stopped if saturations are greater than 96% and should not be started if above 90 to 93%. Exceptions were those with carbon monoxide poisoning, cluster headaches, attacks of sickle cell disease, and pneumothorax. For personal use, high concentration oxygen is used as

title: Oxygen therapy

text: out of hospital. A common use of supplementary oxygen is in patients with chronic obstructive pulmonary disease (COPD), the occurrence of chronic bronchitis or emphysema, a common long-term effect of smoking, who may require additional oxygen to breathe either during a temporary worsening of their condition, or throughout the day and night. It is indicated in COPD patients with arterial oxygen partial pressure Pa ≤ 55 mmHg (7.3 kPa) or arterial oxygen saturation Sa ≤ 88% and has been shown to increase lifespan. Oxygen is often prescribed for people with breathlessness, in the setting of end-stage cardiac or respiratory failure,

title: Liquid oxygen

text: in some commercial and military aircraft as transportable source of breathing oxygen. Because of its cryogenic nature, liquid oxygen can cause the materials it touches to become extremely brittle. Liquid oxygen is also a very powerful oxidizing agent: organic materials will burn rapidly and energetically in liquid oxygen. Further, if soaked in liquid oxygen, some materials such as coal briquettes, carbon black, etc., can detonate unpredictably from sources of ignition such as flames, sparks or impact from light blows. Petrochemicals, including asphalt, often exhibit this behavior. The tetraoxygen molecule (O) was first predicted in 1924 by Gilbert N. Lewis, who

title: Discovered attack

text: called a discovered check. When the moving piece gives check to the opponent's king, the maneuver is often described as a "discovered attack with check". When the discovered attack is itself a check, it is called a "discovered check". If both pieces give check, a double check results. Discovered attacks—especially checks—can win material when the moving piece captures an opposing piece nominally protected by another opposing piece. If the opponent deals with the discovered attack (obligatory if it is a check), the attacking player will have time to return the moving piece out of harm's way. This scenario is often

title: Discovered attack

text: Discovered attack In chess, a discovered attack is an attack revealed when one piece moves out of the way of another. Discovered attacks can be extremely powerful, as the piece moved can make a threat independently of the piece it reveals. Like many chess tactics, they succeed because the opponent is unable to meet two threats at once. While typically the consequence of a discovered attack is the gain of , they do not have to do this to be effective; the tactic can be used merely to gain a tempo. If the discovered attack is a check, it is

title: Discovered attack

text: 2.hxg6++. The result is a "double discovered check": One check is given by the rook, discovered by the capturing pawn's move; the other by the bishop, discovered by the captured pawn's removal. Such a check is extremely rare in practical play, but is sometimes found in problems. The diagram illustrates a trap in the Advance Variation of the French Defence, based on a discovered attack. If, after 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6 5.Nf3 Qb6 6.Bd3 cxd4 7.cxd4, Black mistakenly attempts to win White's d4-pawn with 7...Nxd4 8.Nxd4 Qxd4 (diagram), White can play 9.Bb5+, a discovered attack (White's

title: Oxygen tent

text: in respiratory conditions. Oxygen therapy might be advised for lung diseases, heart conditions, carbon monoxide poisoning, and could be administered to patients in case of surgery. A person with viral or bacterial meningitis who develops breathing difficulty might be kept in an oxygen tent. Certain precautions are usually recommended when using an oxygen tent. One of the measures is to avoid opening the tent very often. If the tent is opened to attend to the patient, the edges need to be tucked back to prevent oxygen from seeping out. In general, it is advisable not to smoke or have any

title: Oxygen therapy

text: home therapy to abort cluster headache attacks, due to its vaso-constrictive effects. People who are receiving oxygen therapy for low oxygen following an acute illness or hospitalization should not routinely have a prescription renewal for continued oxygen therapy without a physician's re-assessment of the person's condition. If the person has recovered from the illness, then the hypoxemia is expected to resolve and additional care would be unnecessary and a waste of resources. Many EMS protocols indicate that oxygen should not be withheld from any patient, while other protocols are more specific or circumspect. However, there are certain situations in which

title: Oxygen therapy

text: respiratory failure in those who are predisposed. Higher oxygen concentrations also increase the risk of fires, particularly while smoking, and without humidification can also dry out the nose. The target oxygen saturation recommended depends on the condition being treated. In most conditions a saturation of 94–96% is recommended, while in those at risk of carbon dioxide retention saturations of 88–92% are preferred, and in those with carbon monoxide toxicity or cardiac arrest they should be as high as possible. Air is typically 21% oxygen by volume while oxygen therapy increases this by some amount up to 100%. The use of

title: Oxygen toxicity

text: oxygen had become identified as a risk factor and its administration restricted. The resulting fall in retinopathy of prematurity was accompanied by a rise in infant mortality and hypoxia-related complications. Since then, more sophisticated monitoring and diagnosis have established protocols for oxygen use which aim to balance between hypoxic conditions and problems of retinopathy of prematurity. Bronchopulmonary dysplasia was first described by Northway in 1967, who outlined the conditions that would lead to the diagnosis. This was later expanded by Bancalari and in 1988 by Shennan, who suggested the need for supplemental oxygen at 36 weeks could predict long-term outcomes.

title: Discovered attack

text: bishop gets out of the way of White's queen) against Black's queen with check. Black must get out of check, then White can follow up with 10.Qxd4. Discovered attack In chess, a discovered attack is an attack revealed when one piece moves out of the way of another. Discovered attacks can be extremely powerful, as the piece moved can make a threat independently of the piece it reveals. Like many chess tactics, they succeed because the opponent is unable to meet two threats at once. While typically the consequence of a discovered attack is the gain of , they do

title: Discovered attack

text: referred to as a "discovered attack" (or "check") "with capture". When the moving piece moves to a square from which it threatens to inflict checkmate on the next move, the tactic is called a "discovered attack with mate threat". A "discovered checkmate" itself is also possible. In exceptional circumstances, it is possible for the moved piece to give a "double discovered check" (though this name is not actually used). The only way for this to happen in orthodox chess is by way of an "en passant" capture. In the position shown at right, Black has just played 1...g7–g5. White replies

title: Emergency oxygen system

text: connected to the oxygen source in the compartment, allowing for it to drop down and hang in front of the passengers. To operate on all aircraft except the L-1011 and B787, they must be pulled sharply toward the passenger who needs it to un-clip the flow pin and start the process of transporting the oxygen to the passenger. Passenger oxygen masks cannot deliver enough oxygen for sustained periods at high altitudes. This is why the flight crew needs to place the aircraft in a controlled emergency descent to a lower altitude where it is possible to breathe without emergency oxygen.

title: Chemical oxygen generator

text: are not used for the cockpit crew, who are typically supplied using compressed oxygen canisters also known as oxygen bottles. In narrow body airliners, for each row of seats there are overhead oxygen masks and oxygen generators. In some wide-body airliners, such as the DC-10 and IL-96, the canisters and oxygen masks are mounted in the top portion of the seat backs, since the ceiling is too high above the passengers. If a decompression occurs, the panels are opened either by an automatic pressure switch or by a manual switch, and the masks are released. When the passengers pull down

title: Oxygen

text: with a small oxy-acetylene flame and then quickly cut by a large stream of . The oxidation state of oxygen is −2 in almost all known compounds of oxygen. The oxidation state −1 is found in a few compounds such as peroxides. Compounds containing oxygen in other oxidation states are very uncommon: −1/2 (superoxides), −1/3 (ozonides), 0 (elemental, hypofluorous acid), +1/2 (dioxygenyl), +1 (dioxygen difluoride), and +2 (oxygen difluoride). Water () is an oxide of hydrogen and the most familiar oxygen compound. Hydrogen atoms are covalently bonded to oxygen in a water molecule but also have an additional attraction (about

title: Oxygen

text: drop. Pulling on the masks "to start the flow of oxygen" as cabin safety instructions dictate, forces iron filings into the sodium chlorate inside the canister. A steady stream of oxygen gas is then produced by the exothermic reaction. Oxygen, as a mild euphoric, has a history of recreational use in oxygen bars and in sports. Oxygen bars are establishments found in the United States since the late 1990s that offer higher than normal exposure for a minimal fee. Professional athletes, especially in American football, sometimes go off-field between plays to don oxygen masks to boost performance. The pharmacological effect

title: Oxygen

text: types of diseased lungs, easing work load on the heart. Oxygen therapy is used to treat emphysema, pneumonia, some heart disorders (congestive heart failure), some disorders that cause increased pulmonary artery pressure, and any disease that impairs the body's ability to take up and use gaseous oxygen. Treatments are flexible enough to be used in hospitals, the patient's home, or increasingly by portable devices. Oxygen tents were once commonly used in oxygen supplementation, but have since been replaced mostly by the use of oxygen masks or nasal cannulas. Hyperbaric (high-pressure) medicine uses special oxygen chambers to increase the partial pressure

title: Oxygen

text: equipment on commercial airliners in case of depressurization emergencies. Another air separation method is forcing air to dissolve through ceramic membranes based on zirconium dioxide by either high pressure or an electric current, to produce nearly pure gas. Oxygen storage methods include high pressure oxygen tanks, cryogenics and chemical compounds. For reasons of economy, oxygen is often transported in bulk as a liquid in specially insulated tankers, since one liter of liquefied oxygen is equivalent to 840 liters of gaseous oxygen at atmospheric pressure and . Such tankers are used to refill bulk liquid oxygen storage containers, which stand outside

title: Oxygen

text: adsorption. Oxygen gas is increasingly obtained by these non-cryogenic technologies (see also the related vacuum swing adsorption). Oxygen gas can also be produced through electrolysis of water into molecular oxygen and hydrogen. DC electricity must be used: if AC is used, the gases in each limb consist of hydrogen and oxygen in the explosive ratio 2:1. A similar method is the electrocatalytic evolution from oxides and oxoacids. Chemical catalysts can be used as well, such as in chemical oxygen generators or oxygen candles that are used as part of the life-support equipment on submarines, and are still part of standard

title: Oxygen

text: metazoa, oxygen was thought to be a requirement for all complex life. Reactive oxygen species, such as superoxide ion () and hydrogen peroxide (), are reactive by-products of oxygen use in organisms. Parts of the immune system of higher organisms create peroxide, superoxide, and singlet oxygen to destroy invading microbes. Reactive oxygen species also play an important role in the hypersensitive response of plants against pathogen attack. Oxygen is damaging to obligately anaerobic organisms, which were the dominant form of early life on Earth until began to accumulate in the atmosphere about 2.5 billion years ago during the Great Oxygenation

title: Oxygen

text: in having such a high concentration of oxygen gas in its atmosphere: Mars (with 0.1% by volume) and Venus have much less. The surrounding those planets is produced solely by the action of ultraviolet radiation on oxygen-containing molecules such as carbon dioxide. The unusually high concentration of oxygen gas on Earth is the result of the oxygen cycle. This biogeochemical cycle describes the movement of oxygen within and between its three main reservoirs on Earth: the atmosphere, the biosphere, and the lithosphere. The main driving factor of the oxygen cycle is photosynthesis, which is responsible for modern Earth's atmosphere. Photosynthesis

title: Oxygen

text: to Rayleigh scattering of blue light). High-purity liquid is usually obtained by the fractional distillation of liquefied air. Liquid oxygen may also be condensed from air using liquid nitrogen as a coolant. Oxygen is a highly reactive substance and must be segregated from combustible materials. The spectroscopy of molecular oxygen is associated with the atmospheric processes of aurora and airglow. The absorption in the Herzberg continuum and Schumann–Runge bands in the ultraviolet produces atomic oxygen that is important in the chemistry of the middle atmosphere. Excited state singlet molecular oxygen is responsible for red chemiluminescence in solution. Naturally occurring oxygen

title: Oxygen

text: reduce the content in eutrophic water bodies. Scientists assess this aspect of water quality by measuring the water's biochemical oxygen demand, or the amount of needed to restore it to a normal concentration. Paleoclimatologists measure the ratio of oxygen-18 and oxygen-16 in the shells and skeletons of marine organisms to determine the climate millions of years ago (see oxygen isotope ratio cycle). Seawater molecules that contain the lighter isotope, oxygen-16, evaporate at a slightly faster rate than water molecules containing the 12% heavier oxygen-18, and this disparity increases at lower temperatures. During periods of lower global temperatures, snow and rain

title: Oxygen tank

text: Oxygen tank An oxygen tank is an oxygen storage vessel, which is either held under pressure in gas cylinders, or as liquid oxygen in a cryogenic storage tank. Oxygen tanks are used to store gas for: Breathing oxygen is delivered from the storage tank to users by use of the following methods: oxygen mask, nasal cannula, full face diving mask, diving helmet, demand valve, oxygen rebreather, built in breathing system (BIBS), oxygen tent, and hyperbaric oxygen chamber. Contrary to popular belief scuba divers very rarely carry oxygen tanks. The vast majority of divers breathe air or nitrox stored in a

title: Oxygen therapy

text: Oxygen therapy Oxygen therapy, also known as supplemental oxygen, is the use of oxygen as a medical treatment. This can include for low blood oxygen, carbon monoxide toxicity, cluster headaches, and to maintain enough oxygen while inhaled anesthetics are given. Long term oxygen is often useful in people with chronically low oxygen such as from severe COPD or cystic fibrosis. Oxygen can be given in a number of ways including nasal cannula, face mask, and inside a hyperbaric chamber. Oxygen is required for normal cell metabolism. Excessively high concentrations can cause oxygen toxicity such as lung damage or result in

title: Oxygen therapy

text: because there is no entrainment of room air, even with the mouth open. This also allows the patient to continue to talk, eat and drink while still receiving the therapy. This type of delivery method is associated with greater overall comfort, and improved oxygenation and respiratory rates than with face mask oxygen. In specialist applications such as aviation, tight fitting masks can be used, and these also have applications in anaesthesia, carbon monoxide poisoning treatment and in hyperbaric oxygen therapy Patients who are unable to breathe on their own will require positive pressure to move oxygen into their lungs for

title: Oxygen toxicity

text: followed by convulsions and unconsciousness, and is of concern to divers who encounter greater than atmospheric pressures. Pulmonary oxygen toxicity results in damage to the lungs, causing pain and difficulty in breathing. Oxidative damage to the eye may lead to myopia or partial detachment of the retina. Pulmonary and ocular damage are most likely to occur when supplemental oxygen is administered as part of a treatment, particularly to newborn infants, but are also a concern during hyperbaric oxygen therapy. Oxidative damage may occur in any cell in the body but the effects on the three most susceptible organs will be

title: Oxygen (horse)

text: Oxygen (horse) Oxygen (foaled 1828, died in winter 1854–1855) was a British Thoroughbred racehorse and broodmare who won the classic Oaks Stakes at Epsom Downs Racecourse in 1831. In a racing career which lasted from July 1830 until April 1833 she won eight of her fifteen races and finished second on five occasions. Oxygen's Oaks was the last of twenty classic wins for her owner George FitzRoy, 4th Duke of Grafton. Oxygen was regarded the leading two-year-old filly in the South of England in 1830, when she won two of her three races. At three she was beaten in a

title: American Oxygen

text: proudly singing the lines, "We sweat for a nickel and a dime, turn it into an empire." According to Jake Flanagin of Quartz, the song is autobiographical to Rihanna and describes her move to the United States in late 2003, when record producer Evan Rogers discovered her in Barbados. VH1's Alexa Tietjen wrote that "American Oxygen" is similar to a presidential speech and "portrays a hurtful past while fostering hope for the future". According to Erika Ramirez of "Billboard", the lyrics of the song describe "pursuit and resilience." CBS Radio's reviewer thought that the final line in the song, "This

title: Oxygen mask

text: use at extreme altitude must be robust and effective. The oxygen storage tanks used with the masks (called oxygen bottles) are made of lightweight, high-strength metals and are covered in high-strength fiber such as kevlar. These special oxygen bottles are filled with oxygen at a very high pressure which provides a longer time duration of oxygen for breathing than standard pressure oxygen bottles. These systems are generally only used above . In recent years oxygen mask systems for high-altitude climbing which pump oxygen constantly have been increasingly replaced by systems supplying oxygen on demand via nasal cannulas. Oxygen helmets are

title: Oxygen therapy

text: Effective May 13, 2009, the Department of Transportation and FAA ruled that a select number of portable oxygen concentrators are approved for use on all commercial flights. FAA regulations require larger airplanes to carry D-cylinders of oxygen for use in an emergency. Oxygen therapy Oxygen therapy, also known as supplemental oxygen, is the use of oxygen as a medical treatment. This can include for low blood oxygen, carbon monoxide toxicity, cluster headaches, and to maintain enough oxygen while inhaled anesthetics are given. Long term oxygen is often useful in people with chronically low oxygen such as from severe COPD or

title: Liquid oxygen (supplement)

text: bronchitis and pneumonia thanks to the product. As of 2010, the product contains a disclaimer stating "This product is not intended to diagnose, treat, cure or prevent any disease". Liquid oxygen (supplement) Liquid oxygen supplements are products that claim to add extra oxygen to the human body, most often through a chemical process in the digestive system, like the breakdown of hydrogen peroxide or magnesium peroxide. While the FDA describes these products as being inert, and has penalized some producers who made explicit medical claims, it has not prohibited their sale. Liquid Oxygen is the name of a product that

title: Liquid oxygen (supplement)

text: Liquid oxygen (supplement) Liquid oxygen supplements are products that claim to add extra oxygen to the human body, most often through a chemical process in the digestive system, like the breakdown of hydrogen peroxide or magnesium peroxide. While the FDA describes these products as being inert, and has penalized some producers who made explicit medical claims, it has not prohibited their sale. Liquid Oxygen is the name of a product that is a solution of hydrogen peroxide and other compounds including sodium chloride (common salt) that claims to help with "jet lag, fatigue, altitude sickness, headaches, hangovers, youthful skin, energy,

title: Oxygen

text: hospitals and other institutions that need large volumes of pure oxygen gas. Liquid oxygen is passed through heat exchangers, which convert the cryogenic liquid into gas before it enters the building. Oxygen is also stored and shipped in smaller cylinders containing the compressed gas; a form that is useful in certain portable medical applications and oxy-fuel welding and cutting. Uptake of from the air is the essential purpose of respiration, so oxygen supplementation is used in medicine. Treatment not only increases oxygen levels in the patient's blood, but has the secondary effect of decreasing resistance to blood flow in many

title: Oxygen

text: bacteria evolved, probably about 3.5 billion years ago. Free oxygen first appeared in significant quantities during the Paleoproterozoic eon (between 3.0 and 2.3 billion years ago). For the first billion years, any free oxygen produced by these organisms combined with dissolved iron in the oceans to form banded iron formations. When such oxygen sinks became saturated, free oxygen began to outgas from the oceans 3–2.7 billion years ago, reaching 10% of its present level around 1.7 billion years ago. The presence of large amounts of dissolved and free oxygen in the oceans and atmosphere may have driven most of the

title: Oxygen

text: Event, about a billion years after the first appearance of these organisms. An adult human at rest inhales 1.8 to 2.4 grams of oxygen per minute. This amounts to more than 6 billion tonnes of oxygen inhaled by humanity per year. The free oxygen partial pressure in the body of a living vertebrate organism is highest in the respiratory system, and decreases along any arterial system, peripheral tissues, and venous system, respectively. Partial pressure is the pressure that oxygen would have if it alone occupied the volume. Free oxygen gas was almost nonexistent in Earth's atmosphere before photosynthetic archaea and

title: Oxygen

text: oxygen is so magnetic that, in laboratory demonstrations, a bridge of liquid oxygen may be supported against its own weight between the poles of a powerful magnet. Singlet oxygen is a name given to several higher-energy species of molecular in which all the electron spins are paired. It is much more reactive with common organic molecules than is molecular oxygen per se. In nature, singlet oxygen is commonly formed from water during photosynthesis, using the energy of sunlight. It is also produced in the troposphere by the photolysis of ozone by light of short wavelength, and by the immune system

title: Oxygen

text: makes up almost half of the Earth's crust. Dioxygen is used in cellular respiration and many major classes of organic molecules in living organisms contain oxygen, such as proteins, nucleic acids, carbohydrates, and fats, as do the major constituent inorganic compounds of animal shells, teeth, and bone. Most of the mass of living organisms is oxygen as a component of water, the major constituent of lifeforms. Oxygen is continuously replenished in Earth's atmosphere by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide. Oxygen is too chemically reactive to remain a free element in

title: Oxygen tank

text: and "oxygen compatible", to reduce the risk of fire. "Oxygen clean" means the removal of any substance that could act as a source of ignition. "Oxygen compatible" means that internal components must not burn readily or degrade easily in a high pressure oxygen environment. In some countries there are legal and insurance requirements and restrictions on the use, storage and transport of pure oxygen. Oxygen tanks are normally stored in well-ventilated locations, far from potential sources of fire and concentrations of people. Oxygen tank An oxygen tank is an oxygen storage vessel, which is either held under pressure in gas

title: Oxygen concentrator

text: much wider range of capacities than medical concentrators. Industrial oxygen concentrators are sometimes referred to as oxygen "generators" within the oxygen and ozone industries to distinguish them from medical oxygen "concentrators". The distinction is used in an attempt to clarify that industrial oxygen concentrators are not [[medical device]]s approved by the [[Food and Drug Administration]] (FDA) and they are not suitable for use as bedside medical concentrators. However, applying the oxygen generator nomenclature can lead to confusion. The term, oxygen "generator," is a misnomer in that the oxygen is not "generated" as it is with a [[chemical oxygen generator]], but

title: Oxygen saturation

text: be applied on both muscle and brain. In medicine, oxygen saturation refers to "oxygenation", or when oxygen molecules () enter the tissues of the body. In this case blood is oxygenated in the lungs, where oxygen molecules travel from the air and into the blood. Oxygen saturation (() sats) measure the percentage of hemoglobin binding sites in the bloodstream occupied by oxygen. Fish, invertebrates, plants, and aerobic bacteria all require oxygen for respiration. In aquatic environments, oxygen saturation is a ratio of the concentration of dissolved oxygen (O) in the water to the maximum amount of oxygen that will dissolve

title: Oxygen balance

text: Oxygen balance Oxygen balance (OB, or OB%) is an expression that is used to indicate the degree to which an explosive can be oxidized. If an explosive molecule contains just enough oxygen to form carbon dioxide from carbon, water from hydrogen atoms, all of its sulfur dioxide from sulfur, and all metal oxides from metals with no excess, the molecule is said to have a zero oxygen balance. The molecule is said to have a positive oxygen balance if it contains more oxygen than is needed and a negative oxygen balance if it contains less oxygen than is needed; the

title: Triplet oxygen

text: Triplet oxygen Triplet oxygen, ""O, refers to the "S" = 1 electronic ground state of molecular oxygen (dioxygen). It is the most stable and common allotrope of oxygen. Molecules of triplet oxygen contain two unpaired electrons, making triplet oxygen an unusual example of a stable and commonly encountered diradical. According to molecular orbital theory, the electron configuration of triplet oxygen has two electrons occupying two π molecular orbitals (MOs) of equal energy (that is, degenerate MOs). In accordance with Hund's rules, they remain unpaired and spin-parallel and account for the paramagnetism of molecular oxygen. These half-filled orbitals are antibonding in

title: Oxygen bar

text: U.S. dollar per minute to inhale a percentage of oxygen greater than the normal atmospheric content of 20.9% oxygen. This oxygen is produced from the ambient air by an industrial (non-medical) oxygen concentrator and inhaled through a nasal cannula for up to about 20 minutes. The machines used by oxygen bars or oxygen vendors differ from the typical medical-issue machine, although customers use the cannula, the rubber tube apparatus that fits around the ears and inserts in the nostrils, to breathe in the oxygen. Customers can enhance their experience by using aromatherapy scents to be added to the oxygen, such

title: Oxygen concentrator

text: enriched gas for use by people requiring medical oxygen due to low oxygen levels in their blood. Oxygen concentrators are also used to provide an economical source of oxygen in industrial processes, where they are also known as oxygen gas generators or oxygen generation plants. Oxygen concentrators utilize a molecular sieve to adsorb gases and operate on the principle of rapid pressure swing adsorption of atmospheric nitrogen onto zeolite minerals and then venting the nitrogen. This type of adsorption system is therefore functionally a nitrogen scrubber leaving the other atmospheric gases to pass through. This leaves oxygen as the primary

title: Oxygen concentrator

text: Oxygen concentrator An oxygen concentrator is a device that concentrates the oxygen from a gas supply (typically ambient air) by selectively removing nitrogen to supply an oxygen-enriched product gas stream. Two methods in common use are pressure swing adsorption and membrane gas separation. Home medical oxygen concentrators were invented in the early 1970s. Manufacturing output of these devices increased in the late 1970s. Union Carbide Corporation (UCC) and Bendix Corporation were both early manufacturers. Prior to that era, home medical oxygen therapy required the use of heavy high pressure oxygen cylinders or small cryogenic liquid oxygen systems. Both of these

title: Oxygen mask

text: used in hyperbaric oxygen chambers for oxygen administration. They are transparent, lightweight plastic helmets with a seal that goes around the wearer's neck that looks like a space suit helmet. They offer a good visual field. Light weight plastic hoses provide oxygen to the helmet and remove exhaled gas to the outside of the chamber. Oxygen helmets are often preferred for oxygen administration in hyperbaric oxygen chambers for children and patients that are uncomfortable wearing an oxygen mask. Medical oxygen masks are held in place by medical personnel or the user by hand, or they may be fitted with a

title: Oxygen mask

text: to revive family pets have been donated to fire departments. Divers only use pure oxygen for accelerated decompression, or from oxygen rebreathers at shallow depths where the risk of acute oxygen toxicity is acceptable. Oxygen supply during in-water decompression is via rebreather, open circuit diving regulator, full-face mask or diving helmet which has been prepared for . Oxygen supply to divers in decompression chambers is preferably through a built-in breathing system, which uses an oxygen mask plumbed into supply and exhaust hoses which supply oxygen from outside the chamber, and discharge the exhaled oxygen-rich gas outside the chamber, using a

title: Oxygen mask

text: but exhalation requires more effort. Aviators are trained in pressure-demand breathing in altitude chambers. Because they seal tightly, pressure-demand-type oxygen masks are also used in hyperbaric oxygen chambers and for oxygen breathing research projects with standard oxygen regulators. Supplemental oxygen is needed for flying more than 30 minutes at cabin pressure altitudes of 12,500 feet or higher, pilots must use oxygen at all times above 14,000 feet and each occupant must be provided supplemental oxygen above 15,000 ft. Most commercial aircraft are fitted with oxygen masks for use when cabin pressurization fails. In general, commercial aircraft are pressurized so that

title: Oxygen mask

text: oxygen mask is controlled by a valve called a regulator. Some types of oxygen masks have a breathing bag made of plastic or rubber attached to the mask or oxygen supply hose to store a supply of oxygen to allow deep breathing without waste of oxygen with use of simple fixed flow regulators. An early 1919 high-altitude oxygen system used a vacuum flask of liquid oxygen to supply two people for one hour at . The liquid passed through several warming stages before use, as expansion when it evaporated, and absorbed latent heat of vaporization, would make the gasified oxygen

title: Oxygen mask

text: Oxygen mask An oxygen mask provides a method to transfer breathing oxygen gas from a storage tank to the lungs. Oxygen masks may cover only the nose and mouth (oral nasal mask) or the entire face (full-face mask). They may be made of plastic, silicone, or rubber. In certain circumstances, oxygen may be delivered via a nasal cannula instead of a mask. Medical plastic oxygen masks are used primarily by medical care providers for oxygen therapy because they are disposable and so reduce cleaning costs and infection risks. Mask design can determine accuracy of oxygen delivered with many various medical

title: Oxygen saturation

text: increasing the concentration of anaerobic over aerobic species. Oxygen saturation Oxygen saturation (symbol S) is a relative measure of the concentration of oxygen that is dissolved or carried in a given medium as a proportion of the maximal concentration that can be dissolved in that medium. It can be measured with a dissolved oxygen probe such as an oxygen sensor or an optode in liquid media, usually water. The standard unit of oxygen saturation is percent (%). Oxygen saturation can be measured regionally and noninvasively. Arterial oxygen saturation (Sa) is commonly measured using pulse oximetry. Tissue saturation at peripheral scale

title: Oxygen saturation

text: Oxygen saturation Oxygen saturation (symbol S) is a relative measure of the concentration of oxygen that is dissolved or carried in a given medium as a proportion of the maximal concentration that can be dissolved in that medium. It can be measured with a dissolved oxygen probe such as an oxygen sensor or an optode in liquid media, usually water. The standard unit of oxygen saturation is percent (%). Oxygen saturation can be measured regionally and noninvasively. Arterial oxygen saturation (Sa) is commonly measured using pulse oximetry. Tissue saturation at peripheral scale can be measured using NIRS. This technique can

title: Oxygen sensor

text: measure respiration or production of oxygen and use a different approach. Oxygen sensors are used in oxygen analyzers, which find extensive use in medical applications such as anesthesia monitors, respirators and oxygen concentrator so. Oxygen sensors are also used in hypoxic air fire prevention systems to continuously monitor the oxygen concentration inside the protected volumes. There are many different ways of measuring oxygen. These include technologies such as zirconia, electrochemical (also known as galvanic), infrared, ultrasonic, paramagnetic, and very recently, laser methods. Automotive oxygen sensors, colloquially known as O ("ō two") sensors, make modern electronic fuel injection and emission control

title: Oxygen toxicity

text: factory brings his experiment to an end. Verne summarised his story by explaining that the effects of oxygen described in the tale were his own invention. There is also a brief episode of oxygen intoxication in his "From the Earth to the Moon". General The following external site is a compendium of resources: Specialised The following external sites contain resources specific to particular topics: Oxygen toxicity Oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen () at increased partial pressures. It is also known as oxygen toxicity syndrome, oxygen intoxication, and oxygen poisoning. Severe cases

title: Oxygen toxicity

text: levels in premature infants receiving oxygen. In low-pressure environments oxygen toxicity may be avoided since the toxicity is caused by high partial pressure of oxygen, not merely by high oxygen fraction. This is illustrated by modern pure oxygen use in spacesuits, which must operate at low pressure (also historically, very high percentage oxygen and lower than normal atmospheric pressure was used in early spacecraft, for example, the Gemini and Apollo spacecraft). In such applications as extra-vehicular activity, high-fraction oxygen is non-toxic, even at breathing mixture fractions approaching 100%, because the oxygen partial pressure is not allowed to chronically exceed .

title: Oxygen toxicity

text: The biochemical basis for the toxicity of oxygen is the partial reduction of oxygen by one or two electrons to form reactive oxygen species, which are natural by-products of the normal metabolism of oxygen and have important roles in cell signalling. One species produced by the body, the superoxide anion (), is possibly involved in iron acquisition. Higher than normal concentrations of oxygen lead to increased levels of reactive oxygen species. Oxygen is necessary for cell metabolism, and the blood supplies it to all parts of the body. When oxygen is breathed at high partial pressures, a hyperoxic condition will

title: Liquid oxygen

text: be oxygen-enriched by letting it stand in open air; atmospheric oxygen dissolves in it, while nitrogen evaporates preferentially. In commerce, liquid oxygen is classified as an industrial gas and is widely used for industrial and medical purposes. Liquid oxygen is obtained from the oxygen found naturally in air by fractional distillation in a cryogenic air separation plant. Air forces have long recognized the strategic importance of liquid oxygen, both as an oxidizer and as a supply of gaseous oxygen for breathing in hospitals and high-altitude aircraft flights. In 1985 the USAF started a program of building its own oxygen-generation facilities

title: Oxygen compatibility

text: are more susceptible to ignition in oxygen-rich environments, and compatibility should be assessed before a component is introduced into an oxygen system. Both pertial pressure and concentration of oxygen affect the fire hazard. The issues of cleaning and design are closely related to the compatibility of materials for safety and durability in oxygen service. Fires occur when oxygen, fuel, and heat energy combine in a self-sustaining chemical reaction. In an oxygen system the presence of oxygen is implied, and in a sufficiently high partial pressure of oxygen, most materials can be considered fuel. Potential ignition sources are present in almost

title: Oxygen equivalent

text: Oxygen equivalent 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 hyperbaric oxygen therapy or medical air transport. It does so by expressing oxygen concentration as a ratio of the partial pressure of oxygen at a given altitude or pressure to Standard Atmospheric Pressure; rather than as a ratio of the

title: Solid oxygen

text: Solid oxygen Solid oxygen forms at normal atmospheric pressure at a temperature below 54.36 K (−218.79 °C, −361.82 °F). Solid oxygen O, like liquid oxygen, is a clear substance with a light sky-blue color caused by absorption in the red part of the visible light spectrum. Oxygen molecules have attracted attention because of the relationship between the molecular magnetization and crystal structures, electronic structures, and superconductivity. Oxygen is the only simple diatomic molecule (and one of the few molecules in general) to carry a magnetic moment. This makes solid oxygen particularly interesting, as it is considered a 'spin-controlled' crystal that

title: Oxygen fluoride

text: Oxygen fluoride Oxygen fluorides are compounds of elements oxygen and fluorine with the general formula OF, where n = 1 to 6. Many different oxygen fluorides are known: Oxygen fluorides are strong oxidizing agents with high energy and can release their energy either instantaneously or at a controlled rate. Thus, these compounds attracted a lot of attention as potential fuels in jet propulsion systems. Here are some synthesis methods and reactions of the three most common oxygen fluorides – oxygen difluoride (OF), dioxygen difluoride (OF) and ozone difluoride (OF). A common preparative method involves fluorination of sodium hydroxide: <chem>2F2 +

title: Oxygen concentrator

text: rather it is concentrated from the air. Non-medical oxygen concentrators can be used as a feed gas to a medical oxygen system, such as the oxygen system in a [[hospital]], though governmental approval is required, such as by the FDA, and additional filtering is generally required. [[Category:Drug delivery devices]] [[Category:Medical equipment]] [[Category:Oxygen]] [[Category:Dosage forms]] [[Category:Industrial gases]] [[Category:Gas technologies]] Oxygen concentrator An oxygen concentrator is a device that concentrates the oxygen from a gas supply (typically ambient air) by selectively removing nitrogen to supply an oxygen-enriched product gas stream. Two methods in common use are pressure swing adsorption and membrane gas

title: Oxygen sensor

text: however commercially available oxygen sensors that measure the oxygen concentration in liquids with great accuracy. There are two types of oxygen sensors available: electrodes (electrochemical sensors) and optodes (optical sensors). The Clark-type electrode is the most used oxygen sensor for measuring oxygen dissolved in a liquid. The basic principle is that there is a cathode and an anode submersed in an electrolyte. Oxygen enters the sensor through a permeable membrane by diffusion and is reduced at the cathode, creating a measurable electric current. There is a linear relationship between the oxygen concentration and the electric current. With a two-point calibration

title: Oxygen therapy

text: is retinopathy of prematurity (ROP). Oxygen has vasoconstrictive effects on the circulatory system, reducing peripheral circulation and was once thought to potentially increase the effects of stroke. However, when additional oxygen is given to the patient, additional oxygen is dissolved in the plasma according to Henry's Law. This allows a compensating change to occur and the dissolved oxygen in plasma supports embarrassed (oxygen-starved) neurons, reduces inflammation and post-stroke cerebral edema. Since 1990, hyperbaric oxygen therapy has been used in the treatments of stroke on a worldwide basis. In rare instances, hyperbaric oxygen therapy patients have had seizures. However, because of

title: Oxygen therapy

text: oxygen in medicine became common around 1917. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. The cost of home oxygen is about US$150 a month in Brazil and US$400 a month in the United States. Home oxygen can be provided either by oxygen tanks or an oxygen concentrator. Oxygen is believed to be the most common treatment given in hospitals in the developed world. Oxygen is used as a medical treatment in both chronic and acute cases, and can be used in hospital, pre-hospital or entirely

title: Oxygen toxicity

text: of tracheobronchitis, or inflammation of the upper airways, after an asymptomatic period between 4 and 22 hours at greater than 95% oxygen, with some studies suggesting symptoms usually begin after approximately 14 hours at this level of oxygen. At partial pressures of oxygen of —100% oxygen at 2 to 3 times atmospheric pressure—these symptoms may begin as early as 3 hours after exposure to oxygen. Experiments on rats breathing oxygen at pressures between suggest that pulmonary manifestations of oxygen toxicity may not be the same for normobaric conditions as they are for hyperbaric conditions. Evidence of decline in lung function

title: Oxygen toxicity

text: oxygen toxicity, with pulmonary and ocular damage being mainly confined to the problems of managing premature infants. In recent years, oxygen has become available for recreational use in oxygen bars. The US Food and Drug Administration has warned those suffering from problems such as heart or lung disease not to use oxygen bars. Scuba divers use breathing gases containing up to 100% oxygen, and should have specific training in using such gases. The effects of oxygen toxicity may be classified by the organs affected, producing three principal forms: Central nervous system oxygen toxicity can cause seizures, brief periods of rigidity

title: Oxygen toxicity

text: high concentrations of supplemental oxygen (particularly premature babies), and those undergoing hyperbaric oxygen therapy. The result of breathing increased partial pressures of oxygen is hyperoxia, an excess of oxygen in body tissues. The body is affected in different ways depending on the type of exposure. Central nervous system toxicity is caused by short exposure to high partial pressures of oxygen at greater than atmospheric pressure. Pulmonary and ocular toxicity result from longer exposure to increased oxygen levels at normal pressure. Symptoms may include disorientation, breathing problems, and vision changes such as myopia. Prolonged exposure to above-normal oxygen partial pressures, or