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Backdraft
A backdraft (North American English) or backdraught (British English) is the abrupt burning of superheated gasses in a fire, caused when oxygen rapidly enters a hot, oxygen-depleted environment; for example, when a window or door to an enclosed space is opened or broken. Backdrafts present a serious threat to firefighters. There is some debate concerning whether backdrafts should be considered a type of flashover (see below). Burning When material is heated enough, it begins to break down into smaller compounds, including hydrogen. This is called pyrolysis, and does not require oxygen. If oxygen is also provided, then the hydrogen can combust, starting a fire. If material undergoing pyrolysis is later given sufficient oxygen, the hydrogen gas will ignite, and therefore, combustion takes place. Cause A backdraft can occur when a compartment fire has little or no ventilation. Due to this, little or no oxygen can flow into the compartment. Then, because fires reduce oxygen, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backdraft (film)
''Backdraft'' is a 1991 American action thriller film directed by Ron Howard and written by Gregory Widen. The film stars Kurt Russell, William Baldwin, Scott Glenn, Jennifer Jason Leigh, Rebecca De Mornay, Donald Sutherland, Robert De Niro, Jason Gedrick, and J. T. Walsh, and follows Chicago firefighters on the trail of a serial arsonist. Filming in Chicago began on July 23, 1990, and was wrapped up on December 8, 1990. Before the filming started, the main actors went out on calls with real Chicago firefighters. All of the main actors also went to the Chicago Fire Academy to learn how to be like the firefighters in the film. The film was released on May 24, 1991 to favorable reviews from critics, and grossed $152.4 million worldwide. The film received three Oscar nominations - Best Sound, Best Sound Editing, and Best Visual Effects - but lost all of these to '' Terminator 2: Judgment Day''. The film also inspired a special effects attraction at Universal Studios Hollywood, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firefighting
Firefighting is the act of extinguishing or preventing the spread of unwanted fires from threatening human lives and destroying property and the environment. A person who engages in firefighting is known as a firefighter. Firefighters typically undergo a high degree of technical training. This involves structural firefighting and wildland firefighting. Specialized training includes aircraft firefighting, shipboard firefighting, aerial firefighting, maritime firefighting, and proximity firefighting. Firefighting is a dangerous profession due to the toxic environment created by combustible materials, with major risks are smoke, oxygen deficiency, elevated temperatures, poisonous atmospheres, and violent air flows. To combat some of these risks, firefighters carry self-contained breathing apparatus. Additional hazards include falls — a constant peril while navigating unfamiliar layouts or confined spaces amid shifting debris under limited visibility – and structural collapse t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firefighter
A firefighter is a first responder and rescuer extensively trained in firefighting, primarily to extinguish hazardous fires that threaten life, property, and the environment as well as to rescue people and in some cases or jurisdictions also animals from dangerous situations. Male firefighters are sometimes referred to as firemen (and, less commonly, a female firefighter as firewoman). The fire service, also known in some countries as the fire brigade or fire department, is one of the three main emergency services. From urban areas to aboard ships, firefighters have become ubiquitous around the world. The skills required for safe operations are regularly practised during training evaluations throughout a firefighter's career. Initial firefighting skills are normally taught through local, regional or state-approved fire academies or training courses. Depending on the requirements of a department, additional skills and certifications such as technical rescue and pre-hospital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flashover
A flashover is the near-simultaneous ignition of most of the directly exposed combustible material in an enclosed area. When certain organic materials are heated, they undergo thermal decomposition and release flammable gases. Flashover occurs when the majority of the exposed surfaces in a space are heated to their autoignition temperature and emit flammable gases (see also flash point). Flashover normally occurs at or for ordinary combustibles and an incident heat flux at floor level of . An example of flashover is the ignition of a piece of furniture in a domestic room. The fire involving the initial piece of furniture can produce a layer of hot smoke, which spreads across the ceiling in the room. The hot buoyant smoke layer grows in depth, as it is bounded by the walls of the room. The radiated heat from this layer heats the surfaces of the directly exposed combustible materials in the room, causing them to give off flammable gases, via pyrolysis. When the temperatures of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North American English
North American English (NAmE, NAE) is the most generalized variety of the English language as spoken in the United States and Canada. Because of their related histories and cultures, plus the similarities between the pronunciations (accents), vocabulary, and grammar of American English and Canadian English, the two spoken varieties are often grouped together under a single category. Canadians are generally tolerant of both British and American spellings, with British spellings of certain words (e.g., ''colour'') being favored in more formal settings and in Canadian print media; for some other words the American spelling prevails over the British (e.g., ''tire'' rather than ''tyre''). Dialects of American English spoken by United Empire Loyalists who fled the American Revolution (1775–1783) have had a large influence on Canadian English from its early roots. Some terms in North American English are used almost exclusively in Canada and the United States (for example, the term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoignition Temperature
The autoignition temperature or kindling point of a substance is the lowest temperature in which it spontaneously ignites in a normal atmosphere without an external source of ignition, such as a flame or spark. This temperature is required to supply the activation energy needed for combustion. The temperature at which a chemical ignites decreases as the pressure is increased. *The ignition temperature of a substance is the lowest temperature at which the substance starts combustion. *Substances which spontaneously ignite in a normal atmosphere at naturally ambient temperatures are termed pyrophoric. Autoignition temperatures of liquid chemicals are typically measured using a flask placed in a temperature-controlled oven in accordance with the procedure described in ASTM E659. When measured for plastics, autoignition temperature can be also measured under elevated pressure and at 100% oxygen concentration. The resulting value is used as a predictor of viability for high-oxyge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Protection
Fire protection is the study and practice of mitigating the unwanted effects of potentially destructive fires. It involves the study of the behaviour, compartmentalisation, suppression and investigation of fire and its related emergencies, as well as the research and development, production, testing and application of mitigating systems. In structures, be they land-based, offshore or even ships, the owners and operators are responsible to maintain their facilities in accordance with a design-basis that is rooted in laws, including the local building code and fire code, which are enforced by the authority having jurisdiction. Buildings must be constructed in accordance with the version of the building code that is in effect when an application for a building permit is made. Building inspectors check on compliance of a building under construction with the building code. Once construction is complete, a building must be maintained in accordance with the current fire code, which is e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire
Fire is the rapid oxidation of a material (the fuel) in the exothermic chemical process of combustion, releasing heat, light, and various reaction Product (chemistry), products. At a certain point in the combustion reaction, called the ignition point, flames are produced. The ''flame'' is the visible portion of the fire. Flames consist primarily of carbon dioxide, water vapor, oxygen and nitrogen. If hot enough, the gases may become ionized to produce Plasma (physics), plasma. Depending on the substances alight, and any impurities outside, the color of the flame and the fire's Intensity (heat transfer), intensity will be different. Fire in its most common form can result in conflagration, which has the potential to cause physical damage through burning. Fire is an important process that affects ecological systems around the globe. The positive effects of fire include stimulating growth and maintaining various ecological systems. Its negative effects include hazard to life and pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combustion
Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion does not always result in fire, because a flame is only visible when substances undergoing combustion vaporize, but when it does, a flame is a characteristic indicator of the reaction. While the activation energy must be overcome to initiate combustion (e.g., using a lit match to light a fire), the heat from a flame may provide enough energy to make the reaction self-sustaining. Combustion is often a complicated sequence of elementary radical reactions. Solid fuels, such as wood and coal, first undergo endothermic pyrolysis to produce gaseous fuels whose combustion then supplies the heat required to produce more of them. Combustion is often hot enough that incandescent light in the form of either glowing or a flame is produced. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter.However, most of the universe's mass is not in the form of baryons or chemical elements. See dark matter and dark energy. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons. In the early universe, the formation of protons, the nuclei of hydrogen, occurred during the first second after the Big Bang. The emergence of neutral hydrogen atoms throughout the universe occurred about 370,000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrolysis
The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements ''pyro'' "fire", "heat", "fever" and '' lysis'' "separating". Pyrolysis is most commonly used in the treatment of organic materials. It is one of the processes involved in charring wood.''Burning of wood'' , InnoFireWood's website. Accessed on 2010-02-06. In general, pyrolysis of organic substances produces volatile products and leaves , a carbon-rich solid residue. Extreme pyrolysis, which leaves mostly |
Before Crime * After Days (BP), a timescale used mainly in geo ...
Before is the opposite of after, and may refer to: * ''Before'' (Gold Panda EP), 2009 * ''Before'' (James Blake EP), 2020 * "Before" (song), a 1996 song by the Pet Shop Boys * "Before", a song by the Empire of the Sun from ''Two Vines'' * "Before", a song by Anastacia from ''Evolution'' * "Before" (short story) by Gael Baudino * The Before film trilogy by Richard Linklater ** ''Before Sunrise'', 1995 ** ''Before Sunset'', 2004 ** ''Before Midnight'' (2013 film) See also *Before Christ (BC), an epoch used in dating years prior to the estimated birth of Jesus *Before Common Era (BCE), an alternative naming of the traditional calendar era primarily used in academic circles *Before Present Before Present (BP) years, or "years before present", is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Becaus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
