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Hydrox (breathing Gas)
Hydrox, a gas mixture of hydrogen and oxygen, was used as a breathing gas in very deep diving. It allows divers to descend several hundred metres. Precautions are necessary when using hydrox, since mixtures containing more than a few percent of both oxygen and hydrogen are explosive if ignited. Hydrogen is the lightest gas (half the weight of helium) but still has a narcotic potential and may cause hydrogen narcosis. History Although the first reported use of hydrogen seems to be Antoine Lavoisier (1743–1794) experimenting on guinea pigs, the actual first uses of this gas in diving are usually attributed to trials by the Swedish engineer, Arne Zetterström in 1945. Zetterström showed that hydrogen was perfectly usable to great depths. Following a fault in using the surface equipment, he died during a demonstration dive. The study of hydrogen was not resumed until several years later by the United States Navy and by the Compagnie maritime d'expertises (Comex), initially duri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter.However, most of the universe's mass is not in the form of baryons or chemical elements. See dark matter and dark energy. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons. In the early universe, the formation of protons, the nuclei of hydrogen, occurred during the first second after the Big Bang. The emergence of neutral hydrogen atoms throughout the universe occurred about 370,000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compagnie Maritime D'expertises
COMEX (or Compagnie Maritime d'Expertises) is a French company specializing in engineering and deep diving operations, created in November 1961 by Henri-Germain Delauze and ran by him until his death in 2012. This company is known worldwide for its technology in regard to underwater exploration at great depths. Its line of business includes: * hyperbaric testing facilities, * oceanographic research ships (Minibex and Janus), * testing pool. COMEX carried out pioneering work in very deep saturation diving. The company experimented with the use of hydrogen in the divers' breathing gas. This work with heliox (a breathing gas mixture of helium and oxygen) and hydreliox (an exotic breathing gas mixture of helium, oxygen and hydrogen gas) mixtures started with Hydra I in 1968. The saturation diving physiology studies were conducted with helium from and with hydrogen from . The diving depth record for off-shore (saturation) diving was achieved in 1988 by a team of COMEX professional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimix (breathing Gas)
Trimix is a breathing gas consisting of oxygen, helium and nitrogen and is used in deep commercial diving, during the deep phase of dives carried out using technical diving techniques, and in advanced recreational diving. The helium is included as a substitute for some of the nitrogen, to reduce the narcotic effect of the breathing gas at depth. With a mixture of three gases it is possible to create mixes suitable for different depths or purposes by adjusting the proportions of each gas. Oxygen content can be optimised for the depth to limit the risk of toxicity, and the inert component balanced between nitrogen (which is cheap but narcotic) and helium (which is not narcotic and reduces work of breathing, but is more expensive and increases heat loss). The mixture of helium and oxygen with a 0% nitrogen content is generally known as heliox. This is frequently used as a breathing gas in deep commercial diving operations, where it is often recycled to save the expensive helium c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrox
Nitrox refers to any gas mixture composed (excepting trace gases) of nitrogen and oxygen. This includes atmospheric air, which is approximately 78% nitrogen, 21% oxygen, and 1% other gases, primarily argon. In the usual application, underwater diving, nitrox is normally distinguished from air and handled differently. The most common use of nitrox mixtures containing oxygen in higher proportions than atmospheric air is in scuba diving, where the reduced partial pressure of nitrogen is advantageous in reducing nitrogen uptake in the body's tissues, thereby extending the practicable underwater dive time by reducing the decompression requirement, or reducing the risk of decompression sickness (also known as ''the bends''). Nitrox is used to a lesser extent in surface-supplied diving, as these advantages are reduced by the more complex logistical requirements for nitrox compared to the use of simple low-pressure compressors for breathing gas supply. Nitrox can also be used in hyper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydreliox
Hydreliox is an exotic breathing gas mixture of helium, oxygen and hydrogen. For the Hydra VIII (Hydra 8) mission at 50 atmospheres of ambient pressure, the mixture used was 49% hydrogen, 50.2% helium, and 0.8% oxygen. It is used primarily for research and scientific deep diving, usually below . Below this depth, extended breathing of heliox gas mixtures may cause high pressure nervous syndrome (HPNS). Two gas mixtures exist that attempt to combat this problem: trimix and hydreliox. Like trimix, hydreliox contains helium and oxygen and a third gas to counteract HPNS. 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%. However, the pressure during the dive must be such that the partial pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliox
Heliox is a breathing gas mixture of helium (He) and oxygen (O2). It is used as a medical treatment for patients with difficulty breathing because mixture generates less resistance than atmospheric air when passing through the airways of the lungs, and thus requires less effort by a patient to breathe in and out of the lungs. It is also used as a breathing gas diluent for deep ambient pressure diving as it is not narcotic at high pressure, and for its low work of breathing. Heliox has been used medically since the 1930s, and although the medical community adopted it initially to alleviate symptoms of upper airway obstruction, its range of medical uses has since expanded greatly, mostly because of the low density of the gas. Heliox is also used in saturation diving and sometimes during the deep phase of technical dives. Medical uses In medicine heliox may refer to a mixture of 21% O2 (the same as air) and 79% He, although other combinations are available (70/30 and 60/40). Hel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argox
Argox is the informal name for a scuba diving breathing gas consisting of argon and oxygen. Occasionally the term ''argonox'' has been used to mean the same mix. The blend may consist of varying fractions of argon and oxygen, depending on its intended use. The mixture is made with the same gas blending techniques used to make nitrox, except that for argox, the argon is added to the initial pure oxygen partial-fill, instead of air. Argox is essentially a theoretical diving gas, being rarely, if ever, used, and usually thought to have no practical applications where its benefits outweigh its drawbacks. Possible uses Human exploration of Mars Argox, or half-argox/half-nitrox is a possible oxygen mixture for human exploration of Mars due to the relative abundance of Argon in the Martian atmosphere. The Martian atmosphere is composed of approximately: 95% , 1.9% argon, 1.9% nitrogen. While it is possible for humans to breathe pure oxygen, a pure oxygen atmosphere was implicated in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gut Flora
Gut microbiota, gut microbiome, or gut flora, are the microorganisms, including bacteria, archaea, fungi, and viruses that live in the digestive tracts of animals. The gastrointestinal metagenome is the aggregate of all the genomes of the gut microbiota. The gut is the main location of the human microbiome. The gut microbiota has broad impacts, including effects on colonization, resistance to pathogens, maintaining the intestinal epithelium, metabolizing dietary and pharmaceutical compounds, controlling immune function, and even behavior through the gut–brain axis. The microbial composition of the gut microbiota varies across regions of the digestive tract. The colon contains the highest microbial density recorded in any habitat on Earth, representing between 300 and 1000 different species. Bacteria are the largest and to date, best studied component and 99% of gut bacteria come from about 30 or 40 species. Up to 60% of the dry mass of feces is bacteria. Over 99% of the bac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decompression Chamber
A diving chamber is a vessel for human occupation, which may have an entrance that can be sealed to hold an internal pressure significantly higher than ambient pressure, a pressurised gas system to control the internal pressure, and a supply of breathing gas for the occupants. There are two main functions for diving chambers: * as a simple form of submersible vessel to transport divers underwater and to provide a temporary base and retrieval system in the depths; * as a land, ship or offshore platform-based hyperbaric chamber or system, to artificially reproduce the hyperbaric conditions under the sea. Internal pressures above normal atmospheric pressure are provided for diving-related applications such as saturation diving and diver decompression, and non-diving medical applications such as hyperbaric medicine. Basic types of diving chambers There are two basic types of submersible diving chambers, differentiated by the way in which the pressure in the diving chamber is pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toulon
Toulon (, , ; oc, label= Provençal, Tolon , , ) is a city on the French Riviera and a large port on the Mediterranean coast, with a major naval base. Located in the Provence-Alpes-Côte d'Azur region, and the Provence province, Toulon is the prefecture of the Var department. The Commune of Toulon has a population of 176,198 people (2018), making it France's 13th-largest city. It is the centre of an urban unit with 580,281 inhabitants (2018), the ninth largest in France. Toulon is the third-largest French city on the Mediterranean coast after Marseille and Nice. Toulon is an important centre for naval construction, fishing, wine making, and the manufacture of aeronautical equipment, armaments, maps, paper, tobacco, printing, shoes, and electronic equipment. The military port of Toulon is the major naval centre on France's Mediterranean coast, home of the French aircraft carrier ''Charles de Gaulle'' and her battle group. The French Mediterranean Fleet is based in Toulon. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theo Mavrostomos
Theo is a given name and a hypocorism. Greek origin Many names beginning with the root "Theo-" derive from the Ancient Greek word ''theos'' (''θεός''), which means god, for example: *Feminine names: Thea, Theodora, Theodosia, Theophania, Theophano and Theoxena *Masculine names: Theodore, Theodoros/Theodorus, Theodosius, Theodotus, Theophanes, Theophilus, Theodoret and Theophylact Germanic origin Many other names beginning with "Theo-" do not necessarily derive from Greek, but rather the old Germanic "theud", meaning "people" or "folk". These names include: *Theobald, Theodahad, Theodard, Theodebert, Theodemir, and Theodoric People with the name Theo See Theo and Théo for a current alphabetical list of all people with the first name Theo or Théo in the English Wikipedia. Among better known people with this name are: * Theo Adam (1926-2019), German classical bass-baritone * Theo Albrecht (1922–2010), German entrepreneur and billionaire * Theo Angelopoulos (19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Pressure Nervous Syndrome
High-pressure nervous syndrome (HPNS – also known as high-pressure neurological syndrome) is a neurological and physiological diving disorder which can result when a diver descends below about using a breathing gas containing helium. The effects experienced, and the severity of those effects, depend on the rate of descent, the depth and the percentage of helium. "Helium tremors" were described in 1965 by Royal Navy physiologist Peter B. Bennett. Russian scientist G. L. Zal'tsman also reported on helium tremors in his experiments from 1961. However, these reports were not available in the West until 1967. The term ''high-pressure nervous syndrome'' was first used by R. W. Brauer in 1968 to describe the combined symptoms of tremor, electroencephalography (EEG) changes, and somnolence that appeared during a chamber dive in Marseille. Symptoms Symptoms of HPNS include tremors, myoclonic jerking, somnolence, EEG changes, visual disturbance, nausea, dizziness, and decrease ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
