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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 run 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] |
Comex Diving Sphere Mg 6143
Comex may refer to: *COMEX (NYMEX), a division of the New York Mercantile Exchange (NYMEX) *COMEX (Compagnie maritime d'expertises), a French company in undersea engineering *Comex Group, a Mexican paint manufacturer and distributor *Commonwealth Expedition, a series of expeditions from Britain to India *Los Comex, a comic book imprint {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metre Sea Water
The metre (or meter) sea water (msw) is a metric unit of pressure used in underwater diving Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving (other), diving, an ambiguous term with several possible meani .... It is defined as one tenth of a bar. or as 1 msw = 10.0381 kPa according to EN 13319. The unit used in the US is the foot sea water (fsw), based on standard gravity and a sea-water density of 64 lb/ft3. According to the US Navy Diving Manual, one fsw equals 0.30643 msw, , or , though elsewhere it states that 33 fsw is (one atmosphere), which gives one fsw equal to about 0.445 psi.Page 2-12. The msw and fsw are the conventional units for measurement of diver pressure exposure used in decompression tables and the unit of calibration for pneumofathometers and hyperbaric chamber pressure gauges. Feet of sea wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Diving Engineering
An underwater environment is a environment of, and immersed in, liquid water in a natural or artificial feature (called a Water, body of water), such as an ocean, sea, lake, pond, reservoir, river, canal, or aquifer. Some characteristics of the underwater environment are universal, but many depend on the local situation. Liquid water has been present on Earth for most of the History of Earth, history of the planet. The underwater environment is thought to be the place of the origin of life on Earth, and it remains the ecological region most critical to the support of life and the natural habitat of the majority of living organisms. Several branches of science are dedicated to the study of this environment or specific parts or aspects of it. A number of human activities are conducted in the more accessible parts of the underwater environment. These include research, underwater diving for work or recreation, and underwater warfare with submarines. It is hostile to humans in many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stirling Engine
A Stirling engine is a heat engine that is operated by the cyclic expansion and contraction of air or other gas (the ''working fluid'') by exposing it to different temperatures, resulting in a net conversion of heat energy to mechanical Work (physics), work. More specifically, the Stirling engine is a closed-cycle regenerative heat engine, with a permanent gaseous working fluid. ''Closed-cycle'', in this context, means a thermodynamic system in which the working fluid is permanently contained within the system. ''Regenerative'' describes the use of a specific type of internal heat exchanger and thermal store, known as the Regenerative heat exchanger, ''regenerator''. Strictly speaking, the inclusion of the regenerator is what differentiates a Stirling engine from other closed-cycle hot air engines. In the Stirling engine, a working fluid (e.g. air) is heated by energy supplied from outside the engine's interior space (cylinder). As the fluid expands, mechanical work is extrac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrolysis Of Water
Electrolysis of water is using electricity to Water splitting, split water into oxygen () and hydrogen () gas by electrolysis. Hydrogen gas released in this way can be used as hydrogen fuel, but must be kept apart from the oxygen as the mixture would be extremely explosive. Separately pressurised into convenient 'tanks' or 'gas bottles', hydrogen can be used for oxyhydrogen welding and other applications, as the hydrogen / oxygen flame can reach approximately 2,800°C. Water electrolysis requires a minimum potential difference of 1.23 volts, although at that voltage external heat is also required. Typically 1.5 volts is required. Electrolysis is rare in industrial applications since hydrogen can be produced less expensively from fossil fuels. Most of the time, hydrogen is made by splitting methane (CH4) into carbon dioxide (CO2) and hydrogen (H2) via steam reforming. This is a carbon-intensive process that means for every kilogram of “grey” hydrogen produced, approximatel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacques-Yves Cousteau
Jacques-Yves Cousteau, (, also , ; 11 June 191025 June 1997) was a French naval officer, oceanographer, filmmaker and author. He co-invented the first successful open-circuit self-contained underwater breathing apparatus (SCUBA), called the Aqua-Lung, which assisted him in producing some of the first underwater documentary, documentaries. Cousteau wrote many books describing his undersea explorations. In his first book, ''The Silent World: A Story of Undersea Discovery and Adventure'', Cousteau surmised the existence of the Animal echolocation, echolocation abilities of porpoises. The book was adapted into an underwater documentary called ''The Silent World''. Co-directed by Cousteau and Louis Malle, it was one of the first films to use underwater photography, underwater cinematography to document the ocean depths color photography, in color. The film won the 1956 at the Cannes Film Festival and remained the only documentary to do so until 2004 (when ''Fahrenheit 9/11'' recei ... [...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. Soviet scientist G. L. Zal'tsman first reported on helium tremors in his experiments from 1961. 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 decreased mental ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediterranean Sea
The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Europe, on the south by North Africa, and on the west almost by the Morocco–Spain border. The Mediterranean Sea covers an area of about , representing 0.7% of the global ocean surface, but its connection to the Atlantic via the Strait of Gibraltar—the narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates the Iberian Peninsula in Europe from Morocco in Africa—is only wide. Geological evidence indicates that around 5.9 million years ago, the Mediterranean was cut off from the Atlantic and was partly or completely desiccation, desiccated over a period of some 600,000 years during the Messinian salinity crisis before being refilled by the Zanclean flood about 5.3 million years ago. The sea was an important ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Professional Diver
Professional diving is underwater diving where the divers are paid for their work. Occupational diving has a similar meaning and applications. The procedures are often regulated by legislation and codes of practice as it is an inherently hazardous occupation and the diver works as a member of a team. Due to the dangerous nature of some professional diving operations, specialized equipment such as an on-site hyperbaric chamber and diver-to-surface communication system is often required by law, and the mode of diving for some applications may be regulated. There are several branches of professional diving, the best known of which is probably commercial diving and its specialised applications, offshore diving, inshore civil engineering diving, marine salvage diving, hazmat diving, and ships husbandry diving. There are also applications in scientific research, marine archaeology, fishing and aquaculture, public service, law enforcement, military service, media work and diver t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturation Diving
Saturation diving is an ambient pressure diving technique which allows a diver to remain at working depth for extended periods during which the body tissues become solubility, saturated with metabolically inert gas from the breathing gas mixture. Once saturated, the time required for Decompression (diving), decompression to surface pressure will not increase with longer exposure. The diver undergoes a single decompression at the end of the exposure of several days to weeks duration. The ratio of productive working time at depth to unproductive decompression time is thereby increased, and the health risk to the diver incurred by decompression is minimised. When a diver breathes pressurized gas, metabolically inert gases are needed in the mixture to dilute oxygen to non-toxic levels. These gases dissolve into the body's tissues, but if they come out of solution too quickly during decompression, they form bubbles in the tissues which can cause decompression sickness ("the bends"), a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydreliox
Hydreliox is an exotic breathing gas mixture of hydrogen, helium, and oxygen. 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 p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), nonmetal, and a potent oxidizing agent that readily forms oxides with most elements as well as with other chemical compound, compounds. Oxygen is abundance of elements in Earth's crust, the most abundant element in Earth's crust, making up almost half of the Earth's crust in the form of various oxides such as water, carbon dioxide, iron oxides and silicates.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. It is abundance of chemical elements, the third-most abundant element in the universe after hydrogen and helium. At standard temperature and pressure, two oxygen atoms will chemical bond, bind covalent bond, covalently to form dioxygen, a colorless and odorless diatomic gas with the chemical formula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
