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Gunpowder Elementary
Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, carbon (in the form of charcoal) and potassium nitrate (saltpeter). The sulfur and carbon act as fuels while the saltpeter is an oxidizer. Gunpowder has been widely used as a propellant in firearms, artillery, rocketry, and pyrotechnics, including use as a blasting agent for explosives in quarrying, mining, building pipelines and road building. Gunpowder is classified as a low explosive because of its relatively slow decomposition rate and consequently low brisance. Low explosives deflagrate (i.e., burn at subsonic speeds), whereas high explosives detonate, producing a supersonic shockwave. Ignition of gunpowder packed behind a projectile generates enough pressure to force the shot from the muzzle at high speed, but usually not enough force to rupture the gun barrel. It thus makes a good propellant but is l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Veterans Weekend, Hull - Panoramio
A veteran () is a person who has significant experience (and is usually adept and esteemed) and expertise in a particular job, occupation or Craft, field. A military veteran is a person who is no longer serving in a military. A military veteran that has served directly in combat in a war is further defined as a war veteran (although not all military conflicts, or areas in which armed combat took place, are necessarily referred to as ''wars''). Military veterans are unique as a group as their lived experience is so strongly connected to the conduct of war in general and application of professional violence in particular. Therefore, there are a large body of knowledge developed through centuries of scholarly studies that seek to describe, understand and explain their lived experience in and out of service. Griffith with colleagues provides an overview of this research field that addresses veterans general health, transition from military service to civilian life, homelessness, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
