|
Air Gun
An air gun or airgun is a gun that fires projectiles pneumatically with compressed air or other gases that are mechanically pressurized ''without'' involving any chemical reactions, in contrast to a firearm, which pressurizes gases ''chemically'' via oxidation of combustible propellants that generates propulsive energy by breaking molecular bonds. Air guns come in both long gun (air rifle) and handgun (air pistol) forms. Both types typically propel metallic projectiles that are either diabolo-shaped pellet (air gun), pellets or spherical round shot, shots called BB (ammunition), BBs, although in recent years Minié ball-shaped cylindro-conoidal bullet, cylindro-conoidal projectiles called slug (projectile), slugs are gaining more popularity. Certain types of air guns (usually air rifles) may also launch fin-stabilized projectile such as flechette, darts (e.g., tranquilizer guns) or hollow-shaft arrows (so-called "airbows"). The first air guns were developed as early as the 16 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BB (ammunition)
A BB gun is a type of air gun designed to shoot metallic spherical projectiles called BBs (not to be confused with similar-looking bearing balls), which are approximately the same size as BB-size lead birdshot used on shotguns ( in diameter). Modern BB guns usually have a smoothbore barrel with a caliber, and use steel balls that measure in diameter and in weight, usually zinc- or copper- plated for corrosion resistance. Some manufacturers still make the slightly larger traditional lead balls that weigh around , which are generally intended for use in rifled barrels (due to lead having better malleability and exerting less wear on riflings). The term "BB gun" is frequently used incorrectly to describe airsoft guns, which shoot plastic pellets (also often referred to as "BBs") that are larger (usually in diameter) but much less dense than metal BBs, and have significantly lower ballistic performance. The term is also sometimes used to describe a pellet gun, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Dioxide
Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. It is a trace gas in Earth's atmosphere at 421 parts per million (ppm), or about 0.04% by volume (as of May 2022), having risen from pre-industrial levels of 280 ppm. Burning fossil fuels is the primary cause of these increased CO2 concentrations and also the primary cause of climate change.IPCC (2022Summary for policy makersiClimate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA Carbon dioxide is soluble in water and is found in groundwater, lakes, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bottled Gas
Bottled gas is a term used for substances which are gaseous at standard temperature and pressure (STP) and have been compressed and stored in carbon steel, stainless steel, aluminum, or composite bottles known as gas cylinders. Gas state in cylinders There are four cases: either the substance remains a gas at standard temperature but increased pressure, the substance liquefies at standard temperature but increased pressure, the substance is dissolved in a solvent, or the substance is liquefied at reduced temperature and increased pressure. In the last case the bottle is constructed with an inner and outer shell separated by a vacuum (dewar flask) so that the low temperature can be maintained by evaporative cooling. Case I The substance remains a ''gas'' at ''standard temperature'' and ''increased pressure'', its critical temperature being below standard temperature. Examples include: * air * argon * fluorine * helium * hydrogen * krypton * nitrogen * oxygen Case II The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piston Pump
A piston pump is a type of positive displacement pump where the high-pressure seal reciprocates with the piston. Piston pumps can be used to move liquids or compress gases. They can operate over a wide range of pressures. High pressure operation can be achieved without adversely affecting flow rate. Piston pumps can also deal with viscous media and media containing solid particles. This pump type functions through a piston cup, oscillation mechanism where down-strokes cause pressure differentials, filling of pump chambers, where up-stroke forces the pump fluid out for use. Piston pumps are often used in scenarios requiring high, consistent pressure and in water irrigation or delivery systems. Types The two main types of piston pump are the lift pump and the force pump. Both types may be operated either by hand or by an engine. Lift pump In a lift pump, the upstroke of the piston draws water, through a valve, into the lower part of the cylinder. On the downstroke, water passes t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spring (device)
A spring is an elastic object that stores mechanical energy. In everyday use the term often refers to coil springs, but there are many different spring designs. Modern springs are typically manufactured from spring steel, although some non-metallic objects like the bow are also springs. When a conventional spring, without stiffness variability features, is compressed or stretched from its resting position, it exerts an opposing force approximately proportional to its change in length (this approximation breaks down for larger deflections). The ''rate'' or ''spring constant'' of a spring is the change in the force it exerts, divided by the change in deflection of the spring. That is, it is the gradient of the force versus deflection curve. An extension or compression spring's rate is expressed in units of force divided by distance, for example or N/m or lbf/in. A torsion spring is a spring that works by twisting; when it is twisted about its axis by an angle, it prod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warfare
War is an intense armed conflict between State (polity), states, governments, Society, societies, or paramilitary groups such as Mercenary, mercenaries, Insurgency, insurgents, and militias. It is generally characterized by extreme violence, destruction, and mortality, using Regular army, regular or Irregular military, irregular Military, military forces. Warfare refers to the common activities and characteristics of types of war, or of wars in general. Total war is warfare that is not restricted to purely legitimate military targets, and can result in massive civilian casualties, civilian or other non-combatant suffering and Casualty (person), casualties. While some war studies scholars consider war a universal and ancestral aspect of human nature, others argue it is a result of specific socio-cultural, economic or ecological circumstances. Etymology The English word ''war'' derives from the 11th-century Old English words ''wyrre'' and ''werre'', from Old French ''werre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shooting Sport
Shooting sports is a group of competitive and recreational sporting activities involving proficiency tests of accuracy, precision and speed in shooting — the art of using ranged weapons, mainly small arms ( firearms and airguns, in forms such as handguns, rifles and shotguns) and bows/ crossbows. Shooting sports can be categorized by equipment, shooting distances, targets, time limits and degrees of athleticism involved. Shooting sports may involve both team and individual competition, and team performance is usually assessed by summing the scores of the individual team members. Due to the noise of shooting and the high (and often lethal) impact energy of the projectiles, shooting sports are typically conducted at either designated permanent shooting ranges or temporary shooting fields in the area away from settlements. History Great Britain Historically, shooting game and target shooting has been limited to the upper-class and the gentry, with severe penalties for poa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hunting
Hunting is the human practice of seeking, pursuing, capturing, or killing wildlife or feral animals. The most common reasons for humans to hunt are to harvest food (i.e. meat) and useful animal products ( fur/ hide, bone/ tusks, horn/ antler, etc.), for recreation/ taxidermy (see trophy hunting), to remove predators dangerous to humans or domestic animals (e.g. wolf hunting), to eliminate pests and nuisance animals that damage crops/ livestock/ poultry or spread diseases (see varminting), for trade/tourism (see safari), or for ecological conservation against overpopulation and invasive species. Recreationally hunted species are generally referred to as the '' game'', and are usually mammals and birds. A person participating in a hunt is a hunter or (less commonly) huntsman; a natural area used for hunting is called a game reserve; an experienced hunter who helps organize a hunt and/or manage the game reserve is known as a gamekeeper. Many non-human anima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arrow
An arrow is a fin-stabilized projectile launched by a bow. A typical arrow usually consists of a long, stiff, straight shaft with a weighty (and usually sharp and pointed) arrowhead attached to the front end, multiple fin-like stabilizers called fletchings mounted near the rear, and a slot at the rear end called a nock for engaging the bowstring. A container or bag carrying additional arrows for convenient reloading is called a quiver. The use of bows and arrows by humans predates recorded history and is common to most cultures. A craftsman who makes arrows is a fletcher, and one that makes arrowheads is an arrowsmith.Paterson ''Encyclopaedia of Archery'' p. 56 History The oldest evidence of likely arrowheads, dating to c. 64,000 years ago, were found in Sibudu Cave, current South Africa.Backwell L, d'Errico F, Wadley L.(2008). Middle Stone Age bone tools from the Howiesons Poort layers, Sibudu Cave, South Africa. Journal of Archaeological Science, 35:1566–1580. B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tranquilizer Gun
A dart gun is an air rifle that fires a dart. The dart is tipped with a hypodermic needle and filled with a tranquilizer, vaccine, or antibiotic. A dart gun containing a tranquillizer is called a tranquillizer gun ( also spelled tranquilizer, tranquilliser or tranquiliser). History The modern dart gun was invented in the 1950s by New Zealander Colin Murdoch. While working with colleagues to study populations of deer and wild goats introduced to New Zealand, he considered that the animals would be easier to catch, examine, and release if a dose of tranquillizer could be administered by projection from afar. To that end, Murdoch went on to develop a range of rifles, darts, and pistols. The first modern remote drug-delivery system was invented by scientists at the University of Georgia in the 1950s, and was the direct predecessor to the Cap-Chur equipment used worldwide for decades. In the early 1960s, a team in Kenya headed by Drs. Tony Pooley and Toni Harthoorn discovered t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flechette
A flechette ( ) is a pointed steel projectile with a vaned tail for stable flight. The name comes from French , "little arrow" or "dart", and sometimes retains the acute accent in English: fléchette. They have been used as ballistic weapons since World War I. Delivery systems and methods of launching flechettes vary, from a single shot, to thousands in a single explosive round. The use of flechettes as antipersonnel weapons has been controversial. Air-dropped During World War I, flechettes were dropped from aircraft to attack infantry and were able to pierce helmets. Later the U.S. used Lazy Dog bombs, which are small, unguided kinetic projectiles typically about in length, in diameter, and weighing about . The weapons were designed to be dropped from an aircraft. They contained no explosive charge but as they fell they developed significant kinetic energy making them lethal and able to easily penetrate soft cover such as jungle canopy, several inches of sand or light ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
