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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 meanings, depending on context. Immersion in water and exposure to high ambient pressure have Physiology, physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done. In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diving Stage
There are several categories of decompression equipment used to help divers Decompression practice, decompress, which is the process required to allow divers to return to the surface safely after spending time underwater at higher ambient pressures. Decompression obligation for a given dive profile must be calculated and monitored to ensure that the risk of decompression sickness is controlled. Some equipment is specifically for these functions, both during planning before the dive and during the dive. Other equipment is used to mark the underwater position of the diver, as a position reference in low visibility or currents, or to assist the diver's ascent and control the depth. Decompression may be shortened ("accelerated") by breathing an oxygen-rich "decompression gas" such as a nitrox blend or pure oxygen. The high partial pressure of oxygen in such decompression mixes produces the effect known as the oxygen window. This decompression gas is often carried by scuba divers i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical Diving
Technical diving (also referred to as tec diving or tech diving) is scuba diving that exceeds the List of diver certification organizations, agency-specified limits of recreational diving for non-Professional diver, professional purposes. Technical diving may expose the diver to hazards beyond those normally associated with recreational diving, and to a greater risk of serious injury or death. Risk may be reduced by using suitable equipment and procedures, which require appropriate knowledge and skills. The required knowledge and skills are preferably developed through specialised training, adequate practice, and experience. The equipment involves breathing gases other than air or standard nitrox mixtures, and multiple gas sources. Most technical diving is done within the limits of training and previous experience, but by its nature, technical diving includes diving which pushes the boundaries of recognised safe practice, and new equipment and procedures are developed and honed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluid Balance
Fluid balance is an aspect of the homeostasis of organisms in which the amount of water in the organism needs to be controlled, via osmoregulation and behavior, such that the concentrations of electrolytes (salts in solution) in the various body fluids are kept within healthy ranges. The core principle of fluid balance is that the amount of water lost from the body must equal the amount of water taken in; for example, in humans, the output (via respiration, perspiration, urination, defecation, and expectoration) must equal the input (via eating and drinking, or by parenteral intake). Euvolemia is the state of normal body fluid volume, including blood volume, interstitial fluid volume, and intracellular fluid volume; hypovolemia and hypervolemia are imbalances. Water is necessary for all life on Earth. Humans can survive for 4 to 6 weeks without food but only for a few days without water. Profuse sweating can increase the need for electrolyte replacement. Water-electrolyte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renal System
The human urinary system, also known as the urinary tract or renal system, consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary system is to eliminate waste from the body, regulate blood volume and blood pressure, control levels of electrolytes and metabolites, and regulate blood pH. The urinary tract is the body's drainage system for the eventual removal of urine. The kidneys have an extensive blood supply via the renal arteries which leave the kidneys via the renal vein. Each kidney consists of functional units called nephrons. Following filtration of blood and further processing, waste (in the form of urine) exits the kidney via the ureters, tubes made of smooth muscle fibres that propel urine towards the urinary bladder, where it is stored and subsequently expelled through the urethra during urination. The female and male urinary system are very similar, differing only in the length of the urethra. 8002,000 milliliters (mL) of urine are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circulatory System
In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek meaning ''heart'', and Latin meaning ''vessels''). The circulatory system has two divisions, a systemic circulation or circuit, and a pulmonary circulation or circuit. Some sources use the terms ''cardiovascular system'' and ''vascular system'' interchangeably with ''circulatory system''. The network of blood vessels are the great vessels of the heart including large elastic arteries, and large veins; other arteries, smaller arterioles, capillaries that join with venules (small veins), and other veins. The circulatory system is closed in vertebrates, which means that the blood never leaves the network of blood vessels. Many invertebrates such as arthropods have an open circulatory system with a he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second World War
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks in World War II, Tanks and Air warfare of World War II, aircraft played major roles, enabling the strategic bombing of cities and delivery of the Atomic bombings of Hiroshima and Nagasaki, first and only nuclear weapons ever used in war. World War II is the List of wars by death toll, deadliest conflict in history, causing World War II casualties, the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Allied-occupied Germany, Germany, Allied-occupied Austria, Austria, Occupation of Japan, Japan, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hunter-gatherer
A hunter-gatherer or forager is a human living in a community, or according to an ancestrally derived Lifestyle, lifestyle, in which most or all food is obtained by foraging, that is, by gathering food from local naturally occurring sources, especially wild edible plants but also insects, Fungus, fungi, Honey hunting, honey, Eggs as food, bird eggs, or anything safe to eat, or by hunting game (pursuing or trapping and killing Wildlife, wild animals, including Fishing, catching fish). This is a common practice among most vertebrates that are omnivores. Hunter-gatherer Society, societies stand in contrast to the more Sedentism, sedentary Agrarian society, agricultural societies, which rely mainly on cultivating crops and raising domesticated animals for food production, although the boundaries between the two ways of living are not completely distinct. Hunting and gathering was humanity's original and most enduring successful Competition (biology), competitive adaptation in the nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diving Helmet
A diving helmet is a rigid head enclosure with a breathing gas supply used in underwater diving. They are worn mainly by professional divers engaged in surface-supplied diving, though some models can be used with scuba equipment. The upper part of the helmet, known colloquially as the ''hat'' or ''bonnet'', may be sealed directly to the diver using a ''neck dam'', connected to a diving suit by a lower part, known as a ''breastplate'', or ''corselet'', depending on regional language preferences, or simply rest on the diver's shoulders, with an open bottom, for shallow water use. The helmet isolates the diver's head from the water, allows the diver to see clearly underwater, provides the diver with breathing gas, protects the diver's head when doing heavy or dangerous work, and usually provides voice communications with the surface (and possibly other divers). If a helmeted diver becomes unconscious but is still breathing, most helmets will remain in place and continue to deliv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Diving Dress
Standard diving dress, also known as hard-hat or copper hat equipment, deep sea diving suit or heavy gear, is a type of diving suit that was formerly used for all relatively deep underwater work that required more than breath-hold duration, which included marine salvage, civil engineering, pearl shell diving and other commercial diving work, and similar naval diving applications. Standard diving dress has largely been superseded by lighter and more comfortable equipment. Standard diving dress consists of a diving helmet made from copper and brass or bronze, clamped over a watertight gasket to a waterproofed canvas suit, an air hose from a surface-supplied manually operated pump or low pressure breathing air compressor, a diving knife, and weights to counteract buoyancy, generally on the chest, back and shoes. Later models were equipped with a diver's telephone for voice communications with the surface. The term ''deep sea diving'' was used to distinguish diving with th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ships Husbandry
Ships husbandry or ship husbandry is all aspects of maintenance, cleaning, and general upkeep of the hull (watercraft), hull, rigging, and equipment of a ship. It may also be used to refer to aspects of maintenance which are not specifically covered by the technical departments. The term is used in both naval and merchant shipping, but ''naval vessel husbandry'' may also be used for specific reference to naval vessels. Etymology Ships husbandry diving Underwater ships husbandry can be financially advantageous when it eliminates the need for dry-dock repairs or extends the interval between dry-dockings, and reduces the time a ship is required to stay in dry-dock. Underwater ship husbandry includes the following operations, usually done by commercial diving, commercial divers, though some can be done by ROVs or robotic machinery: * In-water surface cleaning, Underwater hull cleaning to remove Biofouling, fouling organisms which increase drag, and therefore reduce top speed and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clearance Diving
A clearance diver was originally a specialist naval diver who used explosives underwater to remove obstructions to make harbours and shipping channels safe to navigate, but the term "clearance diver" was later used to include other naval underwater work. Units of clearance divers were first formed during and after World War II to clear ports and harbours in the Mediterranean and Northern Europe of unexploded ordnance and shipwrecks and booby traps laid by the Germans. History Clearance Diving takes its name from the operations carried out towards the end and after the Second World War to clear the ports and harbours of the Mediterranean and Northern Europe of unexploded ordnance and booby traps laid by the Germans.This work was undertaken by RN Rendering Mines Safe (RMS) and Bomb Disposal Units and later by Port Clearance Parties or ‘P’ Parties, two of which (Naval Parties 1571 and 1572) went into action soon after D-Day to clear the vast quantities of unexploded ordnance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Diving
Underwater divers may be employed in any branch of an armed force, including the navy, army, marines, air force and coast guard. Scope of operations includes: search and recovery, search and rescue, hydrographic survey, explosive ordnance disposal, demolition, underwater engineering, salvage, ships husbandry, reconnaissance, infiltration, sabotage, counterifiltration, underwater combat and security. History of military diving Military divers are essential to many missions and campaigns. Combat and demolition work, underwater and coastal reconnaissance, ordnance disposal, search and rescue, salvage operations, construction, ship maintenance and underwater engineering. Every branch of the U.S. military employs divers, and more than 40 nations have military diving units. Military diving is an occupation that has risks and responsibilities beyond those of other professional diving. Research and development in military diving equipment and procedures often eventually contributes t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
