|
Inflatable Structure
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] |
Weather Balloon
A weather balloon, also known as sounding balloon, is a balloon (specifically a type of high-altitude balloon) that carries instruments aloft 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 current condit ... [...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 might 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 ... [...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 malfunctioni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transom (nautical)
A transom is the vertical reinforcement which strengthens the stern of a boat. This flat termination of the stern is typically above the waterline. The term was used as far back as Middle English in the 1300s, having come from Latin ''transversus'' (transverse) via Old French ''traversain'' (set crosswise). The stern of a boat is typically vertical. It can be raked such that there is an overhang above the water, as at the bow. A reverse transom is angled from the waterline forwards. Transoms can be used to support a rudder, outboard motor, or as a swimming and access platform. Gallery File:The Bermuda cedar (Juniperus bermudiana) transom of Spirit of Bermuda, 2016.jpg, The Bermuda cedar transom of the Spirit of Bermuda File:Sea Scooter transom.jpg, Flat transom on a dinghy with mount points for a rudder. File:Coble on shore at Boulmer (2) - geograph.org.uk - 1381157.jpg, Raked transom with rudder mount points. File:CS 30 Sailboat Kelsea 0297.jpg, Reverse transom with rudde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating. 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+ is small and highly charged; as such, it is polarizing, and bonds aluminium forms tend towards covalency. The strong affinity tow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plywood
Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured boards which include medium-density fibreboard (MDF), oriented strand board (OSB) and particle board (chipboard). All plywoods bind resin and wood fibre sheets (cellulose cells are long, strong and thin) to form a composite material. 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 expansion 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—this reduces warping. Because plywood is bonded with grains running against one another and with an odd number of composite ... [...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 o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jumping Castle
Inflatable castles (also called closed inflatable trampolines (CITs), bouncing castles, bouncy houses, bounce houses, jumping castles, jumpers, bouncy castles, moon bounces, or moonwalks) are temporary inflatable structures and buildings and similar items that are rented for functions, school and church festivals and village fetes and used for recreational purposes, particularly for children. The growth in the use of such devices has led to a rental industry that includes inflatable slides, obstacle courses, and games. Inflatables are ideal for portable amusements because they are easy to transport and store. Inflatables have been marketed under several names, such as "Bounce House", "Bouncies", "Moon Bounce", "Boingalow", "Astrojump", "Moonwalk", "Jolly Jump", and "Spacewalk". 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 inven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michael Faraday
Michael Faraday (; 22 September 1791 – 25 August 1867) was an English scientist who contributed to the study of electromagnetism and electrochemistry. His main discoveries include the principles underlying electromagnetic induction, diamagnetism and electrolysis. Although Faraday received little formal education, he was one of the most influential scientists in history. It was by his research on the magnetic field around a conductor carrying a direct current that Faraday established the concept of the electromagnetic field in physics. Faraday also established that magnetism could 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 laws of electrolysis. His inventions of electromagnetic rotary devices formed the foundation of electric motor technology, and it was largely due to his efforts t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematically, density is defined as mass divided by volume: : \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 has the same numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium and iridium are the densest known elements at standard conditions for temperature and pressure. To simplify comparisons of density across different s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
