|
Blast Wall
A blast wall is a barrier designed to protect vulnerable buildings or other structures and the people inside them from the effects of a nearby explosion, whether caused by industrial accident, military action, or terrorism. Effectiveness Research by Cranfield University Defence Academy, building on earlier work, has shown that blast walls have the following properties: * A non-deforming upright wall will significantly reduce the peak blast overpressure and impulse in an area between 4 and 6 wall heights behind it * Similar protection occurs at greater distances behind the wall, but to a diminishing extent * Blast walls perform best if the explosion is relatively close to the front of the wall * "Canopied" walls (with a top section overhanging the front face) show some improved blast protection over plane walls * A 90-degree canopy is more effective than a 45-degree one * Walls containing sand or water work well, and cause little damage if they fail * A wall has to stay intact l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosion
An explosion is a rapid expansion in volume of a given amount of matter associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Explosions may also be generated by a slower expansion that would normally not be forceful, but is not allowed to expand, so that when whatever is containing the expansion is broken by the pressure that builds as the matter inside tries to expand, the matter expands forcefully. An example of this is a Volcano, volcanic eruption created by the expansion of magma in a magma chamber as it rises to the surface. Supersonic explosions created by high explosives are known as detonations and travel through shock waves. wikt:subsonic, Subsonic explosions are created by low explosives through a slower combustion process known as deflagration. Causes For an explosion to occur, there must be a rapid, forceful expansion of matter. There are numerous ways this can happen, both natura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iraq
Iraq, officially the Republic of Iraq, is a country in West Asia. It is bordered by Saudi Arabia to Iraq–Saudi Arabia border, the south, Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq border, the east, the Persian Gulf and Kuwait to the Iraq–Kuwait border, southeast, Jordan to Iraq–Jordan border, the southwest, and Syria to Iraq–Syria border, the west. The country covers an area of and has Demographics of Iraq, a population of over 46 million, making it the List of countries by area, 58th largest country by area and the List of countries by population, 31st most populous in the world. Baghdad, home to over 8 million people, is the capital city and the List of largest cities of Iraq, largest in the country. Starting in the 6th millennium BC, the fertile plains between Iraq's Tigris and Euphrates rivers, referred to as Mesopotamia, fostered the rise of early cities, civilisations, and empires including Sumer, Akkadian Empire, Akkad, and Assyria. Known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revetment (aircraft)
A revetment, in military aviation, is a parking area for one or more aircraft that is surrounded by blast walls on three sides. These walls are as much about protecting neighbouring aircraft as it is to protect the aircraft within the revetment; if a combat aircraft loaded with fuel and munitions was to ignite, a chain reaction might lead to the destruction of its neighbours. The blast walls around a revetment are designed to channel any blast and damage upwards and outwards, away from neighbouring aircraft. Blast pen A blast pen was a specially constructed E-shaped double bay at British Royal Air Force (RAF) Second World War fighter stations, being either or wide and front-to-back, accommodating aircraft for safe-keeping against bomb blasts and shrapnel during air-attacks. Although the pens were open to the sky, the projecting sidewalls preserved the aircraft from all lateral damage, with thick, -high concrete centres and banked-up earth on either side, forming a rou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shockwave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium, but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic speed, supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by Wave interference, constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blast Shelter
A blast shelter is a place where people can go to protect themselves from blasts and explosions, like those from bombs, or in hazardous worksites, such as on oil and gas refineries or petrochemical facilities. It differs from a fallout shelter, in that its main purpose is to protect from shock waves and overpressure instead of from radioactive precipitation, as a fallout shelter does. It is also possible for a shelter to protect from both blasts and fallout. Blast shelters are a vital form of protection from nuclear attacks and are employed in civil defense. There are above-ground, below-ground, dedicated, dual-purpose, and potential blast shelters. Dedicated blast shelters are built specifically for the purpose of blast protection (see bunker). Dual-purpose blast shelters are existing structures with blast-protective properties that have been modified to accommodate people seeking protection from blasts. Potential blast shelters are existing structures or geological features ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Armed Forces
The British Armed Forces are the unified military, military forces responsible for the defence of the United Kingdom, its British Overseas Territories, Overseas Territories and the Crown Dependencies. They also promote the UK's wider interests, support international peacekeeping efforts and provide humanitarian aid. The force is also known as His Majesty's Armed Forces. Since the formation of the united Kingdom of Great Britain in 1707 (later succeeded by the United Kingdom of Great Britain and Ireland, and finally by the United Kingdom of Great Britain and Northern Ireland), the British Armed Forces have seen action in most major wars involving the world's great powers, including the Seven Years' War, the American Revolutionary War, American War of Independence, the Napoleonic Wars, the Crimean War, the First World War and the Second World War. Britain's victories in most of these wars allowed it to influence world events and establish itself as one of the world's leading mili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concertainer
The Concertainer, known colloquially as the Hesco barrier or Hesco bastion, with HESCO being the brand name of the manufacturer, is a modern gabion primarily used for flood control and military fortifications. It is made of a collapsible wire mesh container and heavy-duty fabric liner and is used as a temporary to semi-permanent levee or blast wall against small-arms fire and/or explosives. It has been used during the war on terror in Iraq and Afghanistan. It was originally designed for use on beaches and marshes for erosion and flood control. They were used in 2005 to reinforce levees around New Orleans in the weeks between Hurricane Katrina and Hurricane Rita. During the June 2008 Midwest floods, of HESCO barrier wall were shipped to Iowa. In late March 2009, of HESCO barrier were delivered to Fargo, North Dakota, to protect against floods. In late September 2016, of HESCO barriers were used in Cedar Rapids, Iowa, for the fall flood of 2016. Development The Concertainer w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Armed Forces
The United States Armed Forces are the military forces of the United States. U.S. federal law names six armed forces: the Army, Marine Corps, Navy, Air Force, Space Force, and the Coast Guard. Since 1949, all of the armed forces, except the Coast Guard, have been permanently part of the United States Department of Defense. They form six of the eight uniformed services of the United States. Each of the different military services is assigned a role and domain. The Army conducts land operations. The Navy and Marine Corps conduct maritime operations, the Marine Corps specializing in amphibious and maritime littoral operations primarily for supporting the Navy. The Air Force conducts air operations. The Space Force conducts space operations. The Coast Guard is unique in that it specializes in maritime operations and is also a law enforcement agency. From their inception during the American Revolutionary War, the Army and the Navy, and later the other services, have played a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan, is a landlocked country located at the crossroads of Central Asia and South Asia. It is bordered by Pakistan to the Durand Line, east and south, Iran to the Afghanistan–Iran border, west, Turkmenistan to the Afghanistan–Turkmenistan border, northwest, Uzbekistan to the Afghanistan–Uzbekistan border, north, Tajikistan to the Afghanistan–Tajikistan border, northeast, and China to the Afghanistan–China border, northeast and east. Occupying of land, the country is predominantly mountainous with plains Afghan Turkestan, in the north and Sistan Basin, the southwest, which are separated by the Hindu Kush mountain range. Kabul is the country's capital and largest city. Demographics of Afghanistan, Afghanistan's population is estimated to be between 36 and 50 million. Ancient history of Afghanistan, Human habitation in Afghanistan dates to the Middle Paleolithic era. Popularly referred to as the graveyard of empire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bremer Wall
A Bremer wall, or T-wall, is a portable, steel-reinforced concrete blast wall of the type used for blast protection throughout Iraq and Afghanistan. The Bremer barrier resembles the smaller Jersey barrier, which has been used widely for vehicle traffic control on coalition military bases in Iraq and Afghanistan. To indicate that the Bremer barrier is similar but larger, the , intermediate-sized Bremer barriers are usually referred to as Texas barriers, but not to be confused with the Texas constant-slope barrier. Similarly, the largest barriers, which stand around , are called Alaska barriers. Unlike the Jersey barrier, which has sloped sides at the base, some Texas and Alaska barriers have a rectangular ledge base, usable as a bench for sitting or resting and approximately knee-high for a typical adult. Etymology These T-shaped walls were originally developed by the Israelis in the Israeli West Bank barrier. The term "T-wall" has been used commonly, due to the wall's cros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industrial Accident
A work accident, workplace accident, occupational accident, or accident at work is a "discrete occurrence in the course of work" leading to physical or mental occupational injury. According to the International Labour Organization (ILO), more than 337 million accidents happen on the job each year, resulting, together with occupational diseases, in more than 2.3 million deaths annually. The phrase "in the course of work" can include work-related accidents happening off the company's premises, and can include accidents caused by third parties, according to Eurostat. The definition of work accident includes accidents occurring "while engaged in an economic activity, or at work, or carrying on the business of the employer" according to the ILO. The phrase "physical or mental harm" means any injury, disease, or death. Occupational accidents differ from occupational diseases as accidents are unexpected and unplanned occurrences (e.g., mine collapse), while occupational diseases are " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reinforced Concrete
Reinforced concrete, also called ferroconcrete or ferro-concrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (known as rebar) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as a technique to reinforce the concrete. In terms of volume used annually, it is one of the most common engineering materials. In corrosion engineering terms, when designed correctly, the alkalinity of the concrete protects the steel rebar from corrosion. Description Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
