|
Inflatable Aircraft
An inflatable is an object that can be inflated with a gas, usually with air, but hydrogen, helium, and nitrogen are also used. One of several advantages of an inflatable is that it can be stored in a small space when not inflated, since inflatables depend on the presence of a gas to maintain their size and shape. Function fulfillment per mass used compared with non-inflatable strategies is a key advantage. Stadium cushions, impact guards, vehicle wheel inner tubes, emergency air bags, and inflatable space habitats employ the inflatable principle. Inflation occurs through several strategies: pumps, ram-air, blowing, and suction. Although the term ''inflatable'' can refer to any type of inflatable object, the term is often used in boating to specifically refer to inflatable boats. Types High-pressure vs. low-pressure A distinction is made between high-pressure and low-pressure inflatables. In a high-pressure inflatable, structural limbs like pillars and arches are built out o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weather Balloon
A weather balloon, also known as a sounding balloon, is a balloon (specifically a type of high-altitude balloon) that carries instruments to the stratosphere to send back information on atmospheric pressure, temperature, humidity and wind speed by means of a small, expendable measuring device called a radiosonde. To obtain wind data, they can be tracked by radar, radio direction finding, or navigation systems (such as the satellite-based Global Positioning System, GPS). Balloons meant to stay at a constant altitude for long periods of time are known as ''transosondes''. Weather balloons that do not carry an instrument pack are used to determine upper-level winds and the height of cloud layers. For such balloons, a theodolite or total station is used to track the balloon's azimuth and elevation, which are then converted to estimated wind speed and direction and/or cloud height, as applicable. Weather balloons are launched around the world for observations used to diagnose cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thwart
A thwart is a part of an undecked boat that provides seats for the crew and structural rigidity for the hull. A thwart goes from one side of the hull to the other. There may be just one thwart in a small boat, or many in a larger boat, especially if several oarsmen need to be accommodated. General description A thwart is a part of a boat that usually has two functions: as a seat, and as a structural member that provides some rigidity to the hull. A thwart goes from one side of the hull to the other in an open (undecked) boat, and therefore resists forces pushing in or pulling out the sides of the hull. More obviously it provides a seat for an occupant of a boat. In many sailing boats, a thwart may help support the mast. This can be done either by inserting the mast through a hole in the thwart (with the end resting in a mast step on the keel), or the mast may be clamped to one side of a thwartthis makes it easier to step and unstep the mast whilst afloat. Under oars In a boat p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outboard Motor
An outboard motor is a propulsion system for boats, consisting of a self-contained unit that includes engine, gearbox and propeller or jet drive, designed to be affixed to the outside of the transom. They are the most common motorised method of propelling small watercraft. As well as providing propulsion, outboards provide steering control, as they are designed to pivot over their mountings and thus control the direction of thrust. The skeg also acts as a rudder when the engine is not running. Unlike inboard motors, outboard motors can be easily removed for storage or repairs. In order to eliminate the chances of hitting bottom with an outboard motor, the motor can be tilted up to an elevated position either electronically or manually. This helps when traveling through shallow waters where there may be debris that could potentially damage the motor as well as the propeller. If the electric motor required to move the pistons which raise or lower the engine is malfunction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transom (nautical)
In some boats and ships, a transom is the aft transverse surface of the hull that forms the stern of a vessel. Historically, they are a development from the canoe stern (or "double-ender") wherein which both bow and stern are pointed. Transoms add both strength and width to the stern. They may be flat or curved and they may be vertical, raked forward (known as retroussé), or raked aft. In small boats and yachts, this flat termination of the stern is typically above the waterline, but large commercial vessels often exhibit vertical transoms that dip slightly beneath the water. On cruising boats, a counter stern may be truncated to form a "truncated counter stern", in which there is a part of the stern that approximates a transom. Although that standard stern transom is typically vertical, they may be raked such that there is an overhang above the water, as at the bow. A reverse transom is angled from the waterline forwards. On smaller boats such as dinghies, transoms may be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has a great affinity towards oxygen, passivation (chemistry), forming a protective layer of aluminium oxide, oxide on the surface when exposed to air. It visually resembles silver, both in its color and in its great ability to reflect light. It is soft, magnetism, nonmagnetic, and ductility, ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the abundance of the chemical elements, 12th-most abundant element in the universe. The radioactive decay, radioactivity of aluminium-26, 26Al leads to it being used in radiometric dating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plywood
Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that have been stacked and glued together. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboard (MDF), oriented strand board (OSB), and particle board (or chipboard). All plywoods bind resin and wood fibre sheets (cellulose cells are long, strong and thin) to form a composite material. The sheets of wood are stacked such that each layer has its grain set typically (see below) perpendicular to its adjacent layers. This alternation of the grain is called ''cross-graining'' and has several important benefits: it reduces the tendency of wood to split when nailed at the edges; it reduces thickness swelling and shrinkage, providing improved dimensional stability; and it makes the strength of the panel consistent across all directions. There is usually an odd number of plies, so that the sheet is balanced, that is, the surface layers ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflatable Boat-002
An inflatable is an object that can be inflated with a gas, usually with air, but hydrogen, helium, and nitrogen are also used. One of several advantages of an inflatable is that it can be stored in a small space when not inflated, since inflatables depend on the presence of a gas to maintain their size and shape. Function fulfillment per mass used compared with non-inflatable strategies is a key advantage. Stadium cushions, impact guards, vehicle wheel inner tubes, emergency air bags, and inflatable space habitats employ the inflatable principle. Inflation occurs through several strategies: pumps, ram-air, blowing, and suction. Although the term ''inflatable'' can refer to any type of inflatable object, the term is often used in boating to specifically refer to inflatable boats. Types High-pressure vs. low-pressure A distinction is made between high-pressure and low-pressure inflatables. In a high-pressure inflatable, structural limbs like pillars and arches are built out ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jumping Castle
Inflatable castles (also called bouncy houses, bouncy castles, jumping castles, moon bounces, moonwalks, or closed inflatable trampolines) are temporary inflatable structures and buildings and similar items. They are rented for backyard and block party functions, school and church festivals and fete, village fetes and used for recreational purposes. The growth in the use of such devices has led to a rental industry that includes inflatable slides, inflatable water slides, obstacle courses, and giant games, carnival games, and more. Inflatable castles have been suggested as having some therapeutic value for children with certain sensory impairments, similar to ball pits. History American engineer John Scurlock is credited as inventor of the modern inflatable tent design, in 1958. Scurlock, a plastics specialist who taught at Tulane University and worked for NASA, later also invented the Space Walk safety air cushion used by stunt performers and fire brigades responding to high-r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michael Faraday
Michael Faraday (; 22 September 1791 – 25 August 1867) was an English chemist and physicist who contributed to the study of electrochemistry and electromagnetism. His main discoveries include the principles underlying electromagnetic induction, diamagnetism, and electrolysis. Although Faraday received little formal education, as a self-made man, he was one of the most influential scientists in history. It was by his research on the magnetic field around a Electrical conductor, conductor carrying a direct current that Faraday established the concept of the electromagnetic field in physics. Faraday also established that magnetism could Faraday effect, affect rays of light and that there was an underlying relationship between the two phenomena. the 1911 ''Encyclopædia Britannica''. He similarly discovered the principles of electromagnetic induction, diamagnetism, and the Faraday's laws of electrolysis, laws of electrolysis. His inventions of electric motor, electromagnetic rotar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density
Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be used: \rho = \frac, where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate this quantity is more specifically called specific weight. For a pure substance, the density is equal to its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium is the densest known element at standard conditions for temperature and pressure. To simplify comparisons of density across different systems of units, it is sometimes replaced by the dimensionless quantity "relative den ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
