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Ration Heater
A flameless ration heater (FRH) is a form of self-heating food packaging included in U.S. military Meal, Ready-to-Eat (MRE) rations (since the early 1990s) or similar rations, capable of raising the temperature of an entrée (main course) by in twelve minutes, which has no visible flame. The ration heater contains finely powdered magnesium metal, alloyed with a small amount of iron and table salt. To activate the reaction, a small amount of water is added, and the boiling point of water is quickly reached as the exothermic reaction proceeds. Chemical reaction Ration heaters generate heat in an electron-transfer process called an oxidation-reduction reaction. Water oxidizes magnesium metal, according to the following chemical reaction: : Mg + 2H2O → Mg(OH)2 + H2 heat (q) This reaction is analogous to iron being rusted by oxygen, and proceeds at about the same slow rate, which is too slow to generate usable heat. To accelerate the reaction, metallic iron particles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heaters
A heater is an appliance whose purpose is to generate heat for a building. Heater or Heaters may also refer to: Science, technology and engineering * Central heating, a system used to heat an entire building Devices * Aquarium heater, in fishkeeping, used to warm aquarium water * Boiler or heater, used to heat water for use in a heating system * Furnace or heater, used to heat buildings using a central system * Radiator (heating) or heater, used to transmit heat from a boiler * Space heater, that heats a single area ** Gas heater, that heats a area using gas ** Oil heater, that heats oil to heat a room Physics * Heating element, a device that converts electricity into heat * Cathode heater, in vacuum tubes and gas-filled tubes ** Heater, a vacuum tube filament for an indirectly heated cathode in a vacuum tube Music * Heaters (band), an American rock band * "The Heater", a song by The Mutton Birds * "Heater" (Samim song), a song by Samim * "Heaters", a song on the IllScarlett a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Food Of The United States
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distinct military uniform. It may consist of one or more military branches such as an army, navy, air force, space force, marines, or coast guard. The main task of the military is usually defined as defence of the state and its interests against external armed threats. In broad usage, the terms ''armed forces'' and ''military'' are often treated as synonymous, although in technical usage a distinction is sometimes made in which a country's armed forces may include both its military and other paramilitary forces. There are various forms of irregular military forces, not belonging to a recognized state; though they share many attributes with regular military forces, they are less often referred to as simply ''military''. A nation's military may f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Packaging
The terms active packaging, intelligent packaging, smart packaging and connected packaging refer to packaging systems used with foods, pharmaceuticals, and several other types of products. They help extend shelf life, monitor freshness, display information on quality, improve safety, and improve convenience. The terms are closely related. ''Active packaging'' usually means having active functions beyond the inert passive containment and protection of the product. ''Intelligent'' and ''smart'' packaging usually involve the ability to sense or measure an attribute of the product, the inner atmosphere of the package, or the shipping environment. This information can be communicated to users or can trigger active packaging functions. Programmable matter, smart materials, etc. can be employed in packages. Depending on the working definitions, some traditional types of packaging might be considered as "active" or "intelligent". More often, the terms are used with new technologicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Aviation Administration
The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic management, certification of personnel and aircraft, setting standards for airports, and protection of U.S. assets during the launch or re-entry of commercial space vehicles. Powers over neighboring international waters were delegated to the FAA by authority of the International Civil Aviation Organization. Created in , the FAA replaced the former Civil Aeronautics Administration (CAA) and later became an agency within the U.S. Department of Transportation. Major functions The FAA's roles include: *Regulating U.S. commercial space transportation *Regulating air navigation facilities' geometric and flight inspection standards *Encouraging and developing civil aeronautics, including new aviation technology *Issuing, suspending, or revoking ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galvanic Cell
A galvanic cell or voltaic cell, named after the scientists Luigi Galvani and Alessandro Volta, respectively, is an electrochemical cell in which an electric current is generated from spontaneous Oxidation-Reduction reactions. A common apparatus generally consists of two different metals, each immersed in separate beakers containing their respective metal ions in solution that are connected by a salt bridge or separated by a porous membrane. Volta was the inventor of the voltaic pile, the first Battery (electricity), electrical battery. In common usage, the word "battery" has come to include a single galvanic cell, but a battery properly consists of multiple cells. History In 1780, Luigi Galvani discovered that when two different metals (e.g., copper and zinc) are in contact and then both are touched at the same time to two different parts of a muscle of a frog leg, to close the circuit, the frog's leg contracts. He called this "bioelectricity, animal electricity". The frog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrolyte
An electrolyte is a medium containing ions that is electrically conducting through the movement of those ions, but not conducting electrons. This includes most soluble salts, acids, and bases dissolved in a polar solvent, such as water. Upon dissolving, the substance separates into cations and anions, which disperse uniformly throughout the solvent. Solid-state electrolytes also exist. In medicine and sometimes in chemistry, the term electrolyte refers to the substance that is dissolved. Electrically, such a solution is neutral. If an electric potential is applied to such a solution, the cations of the solution are drawn to the electrode that has an abundance of electrons, while the anions are drawn to the electrode that has a deficit of electrons. The movement of anions and cations in opposite directions within the solution amounts to a current. Some gases, such as hydrogen chloride (HCl), under conditions of high temperature or low pressure can also function as electrolytes. El ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redox
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate (chemistry), substrate change. Oxidation is the loss of Electron, electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. There are two classes of redox reactions: * ''Electron-transfer'' – Only one (usually) electron flows from the reducing agent to the oxidant. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * ''Atom transfer'' – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation reactions are commonly associated with the formation of oxides, other chemical species can serve the same function. In hydrogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exothermic Reaction
In thermochemistry, an exothermic reaction is a "reaction for which the overall standard enthalpy change Δ''H''⚬ is negative." Exothermic reactions usually release heat. The term is often confused with exergonic reaction, which IUPAC defines as "... a reaction for which the overall standard Gibbs energy change Δ''G''⚬ is negative." A strongly exothermic reaction will usually also be exergonic because Δ''H''⚬ makes a major contribution to Δ''G''⚬. Most of the spectacular chemical reactions that are demonstrated in classrooms are exothermic and exergonic. The opposite is an endothermic reaction, which usually takes up heat and is driven by an entropy increase in the system. Examples Examples are numerous: combustion, the thermite reaction, combining strong acids and bases, polymerizations. As an example in everyday life, hand warmers make use of the oxidation of iron to achieve an exothermic reaction: :4Fe + 3O2 → 2Fe2O3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
