European Chemicals Agency
The European Chemicals Agency is an agency of the European Union which manages the technical and administrative aspects of the implementation of the European Union regulation called Registration, Evaluation and Restriction of Chemicals. ECHA is the driving force among regulatory authorities in implementing the EU's chemicals legislation. ECHA helps companies to comply with the legislation, advances the safe use of chemicals, provides information on chemicals and addresses chemicals of concern, it is located in Finland. The agency headed by Executive Director Bjorn Hansen, started working on 1 June 2007; the REACH Regulation requires companies to provide information on the hazards and safe use of chemical substances that they manufacture or import. Companies register this information with ECHA and it is freely available on their website. So far, thousands of the most hazardous and the most used substances have been registered; the information is technical but gives detail on the impact of each chemical on people and the environment.
This gives European consumers the right to ask retailers whether the goods they buy contain dangerous substances. The Classification and Packaging Regulation introduces a globally harmonised system for classifying and labelling chemicals into the EU; this worldwide system makes it easier for workers and consumers to know the effects of chemicals and how to use products safely because the labels on products are now the same throughout the world. Companies need to notify ECHA of the labelling of their chemicals. So far, ECHA has received over 5 million notifications for more than 100 000 substances; the information is available on their website. Consumers can check chemicals in the products. Biocidal products include, for example, insect disinfectants used in hospitals; the Biocidal Products Regulation ensures that there is enough information about these products so that consumers can use them safely. ECHA is responsible for implementing the regulation; the law on Prior Informed Consent sets guidelines for the import of hazardous chemicals.
Through this mechanism, countries due to receive hazardous chemicals are informed in advance and have the possibility of rejecting their import. Substances that may have serious effects on human health and the environment are identified as Substances of Very High Concern 1; these are substances which cause cancer, mutation or are toxic to reproduction as well as substances which persist in the body or the environment and do not break down. Other substances considered. Companies manufacturing or importing articles containing these substances in a concentration above 0,1% weight of the article, have legal obligations, they are required to inform users about the presence of the substance and therefore how to use it safely. Consumers have the right to ask the retailer whether these substances are present in the products they buy. Once a substance has been identified in the EU as being of high concern, it will be added to a list; this list is available on ECHA's website and shows consumers and industry which chemicals are identified as SVHCs.
Substances placed on the Candidate List can move to another list. This means that, after a given date, companies will not be allowed to place the substance on the market or to use it, unless they have been given prior authorisation to do so by ECHA. One of the main aims of this listing process is to phase out SVHCs where possible. In its 2018 substance evaluation progress report, ECHA said chemical companies failed to provide “important safety information” in nearly three quarters of cases checked that year. "The numbers show a similar picture to previous years" the report said. The agency noted that member states need to develop risk management measures to control unsafe commercial use of chemicals in 71% of the substances checked. Executive Director Bjorn Hansen called non-compliance with REACH a "worry". Industry group CEFIC acknowledged the problem; the European Environmental Bureau called for faster enforcement to minimise chemical exposure. European Chemicals Bureau Official website
Camping is an outdoor activity involving overnight stays away from home in a shelter, such as a tent. Participants leave developed areas to spend time outdoors in more natural ones in pursuit of activities providing them enjoyment. To be regarded as "camping" a minimum of one night is spent outdoors, distinguishing it from day-tripping and other short-term recreational activities. Camping can be enjoyed through all four seasons. Luxury may be an element, as in early 20th century African safaris, but including accommodations in equipped fixed structures such as high-end sporting camps under the banner of "camping" blurs the line. Camping as a recreational activity became popular among elites in the early 20th century. With time, it grew more democratic, varied. Modern campers frequent publicly owned natural resources such as national and state parks, wilderness areas, commercial campgrounds. Camping is a key part of many youth organizations around the world, such as Scouting, which use it to teach both self-reliance and teamwork.
Camping describes a range of approaches to outdoor accommodation. Survivalist campers set off with as little as possible to get by, whereas recreational vehicle travelers arrive equipped with their own electricity and patio furniture. Camping may be combined with hiking, as in backpacking, is enjoyed in conjunction with other outdoor activities such as canoeing, climbing and hunting. Fastpacking involves both running and camping. There is no universally held definition of what is not camping. Just as with motels which serve both recreational and business guests, the same campground may serve recreational campers, migrant workers, homeless at the same time. Fundamentally, it reflects the nature of activities involved. A children's summer camp with dining hall meals and bunkhouse accommodations may have "camp" in its name but fails to reflect the spirit and form of "camping" as it is broadly understood. A homeless person's lifestyle may involve many common camping activities, such as sleeping out and preparing meals over a fire, but fails to reflect the elective nature and pursuit of spirit rejuvenation that are integral aspect of camping.
Cultures with itinerant lifestyles or lack of permanent dwellings cannot be said to be "camping", it is just their way of life. The history of recreational camping is traced back to Thomas Hiram Holding, a British travelling tailor, but it was first popularised in the UK on the river Thames. By the 1880s large numbers of visitors took part in the pastime, connected to the late Victorian craze for pleasure boating; the early camping equipment was heavy, so it was convenient to transport it by boat or to use craft that converted into tents. Although Thomas Hiram Holding is seen as the father of modern camping in the UK, he was responsible for popularising a different type of camping in the early twentieth century, he experienced the activity in the wild from his youth, when he had spent much time with his parents traveling across the American prairies. He embarked on a cycling and camping tour with some friends across Ireland, his book on his Ireland experience and Camp in Connemara led to the formation of the first camping group in 1901, the Association of Cycle Campers to become the Camping and Caravanning Club.
He wrote The Campers Handbook in 1908, so that he could share his enthusiasm for the great outdoors with the world. The first commercial camping ground in the world was Cunningham’s camp, near Douglas, Isle of Man, which opened in 1894. In 1906 the Association of Cycle Campers opened its first own camping site, in Weybridge. By that time the organization had several hundred members. In 1910 the Association was merged into the National Camping Club. Although WW1 was responsible for a certain hiatus in camping activity, the association received a new lease of life after the war when Sir Robert Baden-Powell became its president. In the US, camping may be traced to William Henry Harrison Murray 1869 publication of Camp-Life in the Adirondacks resulting in a flood of visitors to the Adirondacks that summer; the International Federation of Camping Clubs was founded in 1932 with national clubs from all over the world affiliating with it. By the 1960s camping had become an established family holiday standard and today camp sites are ubiquitous across Europe and North America.
Different types camping may be named after their form of transportation, such as with Canoe camping, car camping, RVing, backpacking, which can involve ultralight gear. Camping is labeled by lifestyle: Glamping combines camping with the luxury and amenities of a home or hotel, has its roots are in the early 1900s European and American safaris in Africa. Workamping allows campers to trade their labor variously for discounts on campsite fees, campground utilities, some degree of pay. Migrant camps are formed not as a temporary housing arrangement. Campgrounds for custom harvesters in the United States may include room to park combines and other large farm equipment. Another way of describing camping is by the manner of arrangement: reservation camping vs. drop camping. Campgrounds may require campers to check in with an employee or campground host prior to setting up camp, or they may allow "drop camping, where this is not required. Drop-in campsites may be free or a drop-box may be provided to accept payments on the honor system.
Although drop camping is specifically allowed by law, it may exist in a legal grey area, such as at California's Slab City. Social media oriented towa
Chloroform, or trichloromethane, is an organic compound with formula CHCl3. It is a colorless, sweet-smelling, dense liquid, produced on a large scale as a precursor to PTFE, it is a precursor to various refrigerants. It is one of a trihalomethane, it is a powerful anesthetic, euphoriant and sedative when inhaled or ingested. The molecule adopts a tetrahedral molecular geometry with C3v symmetry; the total global flux of chloroform through the environment is 660000 tonnes per year, about 90% of emissions are natural in origin. Many kinds of seaweed produce chloroform, fungi are believed to produce chloroform in soil. Abiotic process is believed to contribute to natural chloroform productions in soils although the mechanism is still unclear. Chloroform volatilizes from soil and surface water and undergoes degradation in air to produce phosgene, formyl chloride, carbon monoxide, carbon dioxide, hydrogen chloride, its half-life in air ranges from 55 to 620 days. Biodegradation in water and soil is slow.
Chloroform does not bioaccumulate in aquatic organisms. Chloroform was synthesized independently by several investigators circa 1831: Moldenhawer, a German pharmacist from Frankfurt an der Oder, appears to have produced chloroform in 1830 by mixing chlorinated lime with ethanol. Samuel Guthrie, an American physician from Sackets Harbor, New York appears to have produced chloroform in 1831 by reacting chlorinated lime with ethanol, as well as noting its anaesthetic properties. Justus von Liebig carried out the alkaline cleavage of chloral. Eugène Soubeiran obtained the compound by the action of chlorine bleach on both acetone. In 1834, French chemist Jean-Baptiste Dumas named it. In 1835, Dumas prepared the substance by the alkaline cleavage of trichloroacetic acid. Regnault prepared chloroform by chlorination of chloromethane. In 1842, Robert Mortimer Glover in London discovered the anaesthetic qualities of chloroform on laboratory animals. In 1847, Scottish obstetrician James Y. Simpson was the first to demonstrate the anaesthetic properties of chloroform on humans and helped to popularise the drug for use in medicine.
By the 1850s, chloroform was being produced on a commercial basis by using the Liebig procedure, which retained its importance until the 1960s. Today, chloroform — along with dichloromethane — is prepared and on a massive scale by the chlorination of methane and chloromethane. In industry, chloroform is produced by heating a mixture of chlorine and either chloromethane or methane. At 400–500 °C, a free radical halogenation occurs, converting these precursors to progressively more chlorinated compounds: CH4 + Cl2 → CH3Cl + HCl CH3Cl + Cl2 → CH2Cl2 + HCl CH2Cl2 + Cl2 → CHCl3 + HClChloroform undergoes further chlorination to yield carbon tetrachloride: CHCl3 + Cl2 → CCl4 + HClThe output of this process is a mixture of the four chloromethanes, which can be separated by distillation. Chloroform may be produced on a small scale via the haloform reaction between acetone and sodium hypochlorite: 3 NaClO + 2CO → CHCl3 + 2 NaOH + NaOCOCH3 Deuterated chloroform is an isotopologue of chloroform with a single deuterium atom.
CDCl3 is a common solvent used in NMR spectroscopy. Deuterochloroform is produced by the haloform reaction, the reaction of acetone with sodium hypochlorite or calcium hypochlorite; the haloform process is now obsolete for the production of ordinary chloroform. Deuterochloroform can be prepared by the reaction of sodium deuteroxide with chloral hydrate; the haloform reaction can occur inadvertently in domestic settings. Bleaching with hypochlorite generates halogenated compounds in side reactions. Sodium hypochlorite solution mixed with common household liquids such as acetone, methyl ethyl ketone, ethanol, or isopropyl alcohol can produce some chloroform, in addition to other compounds such as chloroacetone or dichloroacetone. In terms of scale, the most important reaction of chloroform is with hydrogen fluoride to give monochlorodifluoromethane, a precursor in the production of polytetrafluoroethylene: CHCl3 + 2 HF → CHClF2 + 2 HClThe reaction is conducted in the presence of a catalytic amount of mixed antimony halides.
Chlorodifluoromethane is converted into tetrafluoroethylene, the main precursor to Teflon. Before the Montreal Protocol, chlorodifluoromethane was a popular refrigerant; the hydrogen attached to carbon in chloroform participates in hydrogen bonding. Worldwide, chloroform is used in pesticide formulations, as a solvent for fats, rubber, waxes, gutta-percha, resins, as a cleansing agent, grain fumigant, in fire extinguishers, in the rubber industry. CDCl3 is a common solvent used in NMR spectroscopy; as a reagent, chloroform serves as a source of the dichlorocarbene CCl2 group. It reacts with aqueous sodium hydroxide in the presence of a phase transfer catalyst to produce dichlorocarbene, CCl2; this reagent effects ortho-formylation of activated aromatic rings such as phenols, producing aryl aldehydes in a reaction known as the Reimer–Tiemann reaction. Alternatively, the carbene can be trapped by an alkene to form a cyclopropane derivative. In the Kharasch addition, chloroform forms the CHCl2 free radical in addition to alkenes.
The anaesthetic qualities of chloroform were first described in 1842 in a thesis by Robert Mortimer Glover, which won t
Polyoxymethylene known as acetal and polyformaldehyde, is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, excellent dimensional stability. As with many other synthetic polymers, it is produced by different chemical firms with different formulas and sold variously by such names as Delrin, Ramtal, Duracon and Hostaform. POM is characterized by its high strength and rigidity to −40 °C. POM is intrinsically opaque white, due to its high crystalline composition, but it is available in all colors. POM has a density of 1.410–1.420 g/cm3. Typical applications for injection-molded POM include high-performance engineering components such as small gear wheels, eyeglass frames, ball bearings, ski bindings, guns, knife handles, lock systems; the material is used in the automotive and consumer electronics industry. Polyoxymethylene was discovered by Hermann Staudinger, a German chemist who received the 1953 Nobel Prize in Chemistry, he had studied the polymerization and structure of POM in the 1920s while researching macromolecules, which he characterized as polymers.
Due to problems with thermal stability, POM was not commercialized at that time. Around 1952, research chemists at DuPont synthesized a version of POM, in 1956 the company filed for patent protection of the homopolymer. DuPont credits R. N. MacDonald as the inventor of high-molecular-weight POM. Patents by MacDonald and coworkers describe the preparation of high-molecular-weight hemiacetal-terminated POM, but these lack sufficient thermal stability to be commercially viable; the inventor of a heat-stable POM homopolymer was Stephen Dal Nogare, who discovered that reacting the hemiacetal ends with acetic anhydride converts the depolymerizable hemiacetal into a thermally stable, melt-processable plastic. In 1960, DuPont completed construction of a plant to produce its own version of acetal resin, named Delrin, at Parkersburg, West Virginia. In 1960, Celanese completed its own research. Shortly thereafter, in a limited partnership with the Frankfurt firm Hoechst AG, a factory was built in Kelsterbach, Hessen.
Both remain in production under the auspices of Celanese and are sold as parts of a product group now called Hostaform/Celcon POM. Different manufacturing processes are used to produce the homopolymer and copolymer versions of POM. To make polyoxymethylene homopolymer, anhydrous formaldehyde must be generated; the principal method is by reaction of the aqueous formaldehyde with an alcohol to create a hemiformal, dehydration of the hemiformal/water mixture and release of the formaldehyde by heating the hemiformal. The formaldehyde is polymerized by anionic catalysis, the resulting polymer stabilized by reaction with acetic anhydride. Due to the manufacturing process, large-diameter cross-sections may have pronounced centerline porosity. A typical example is DuPont’s Delrin; the polyoxymethylene copolymer replaces about 1–1.5% of the −CH2O− groups with −CH2CH2O−. To make polyoxymethylene copolymer, formaldehyde is converted to trioxane; this is done by acid catalysis followed by purification of the trioxane by distillation and/or extraction to remove water and other active hydrogen-containing impurities.
Typical copolymers are Hostaform from Celanese and Ultraform from BASF. The co-monomer is dioxolane, but ethylene oxide can be used. Dioxolane is formed by reaction of ethylene glycol with aqueous formaldehyde over an acid catalyst. Other diols can be used. Trioxane and dioxolane are polymerized using an acid catalyst boron trifluoride etherate, BF3OEt2; the polymerization can take place in neat trioxane. After polymerization, the acidic catalyst must be deactivated and the polymer stabilized by melt or solution hydrolysis to remove unstable end groups. Stable polymer is melt-compounded, adding thermal and oxidative stabilizers and optionally lubricants and miscellaneous fillers. POM is supplied in a granulated form and can be formed into the desired shape by applying heat and pressure; the two most common forming methods employed are injection extrusion. Rotational molding and blow molding are possible. Typical applications for injection-molded POM include high-performance engineering components.
The material is used in the automotive and consumer electronics industry. There are special grades that offer higher mechanical toughness, stiffness or low-friction/wear properties. POM is extruded as continuous lengths of round or rectangular section; these sections can be sold as bar or sheet stock for machining. When supplied as extruded bar or sheet, POM may be machined using traditional methods such as turning, drilling etc; these techniques are best employed where production economics do not merit the expense of melt processing. The material does require sharp tools with a high clearance angle; the use of soluble cutting lubricant is recommended. POM sheets can be cut cleanly and using an infrared laser, such as in a CO2 laser cutter; because the material lacks the rigidity of most metals, care should be taken to use light clamping forces and sufficient support for the work piece. As can be the case with many polymers, machined POM can be dimensionally unstable with parts that have large variati
Hexamine fuel tablet
A hexamine fuel tablet is a form of solid fuel in tablet form. The tablets burn smokelessly, have a high energy density, do not liquefy while burning and leave no ashes. Invented in Murrhardt, Germany, in 1936, the main component is hexamine, discovered by Aleksandr Butlerov in 1859; some fuel tablets use 1,3,5-trioxane as another ingredient. Esbit is a genericized trademark that people use to refer to similar products made by other companies. In most countries from the former Soviet bloc, fuel tablets are called dry alcohol; the tablets are used for cooking by the military and relief organizations. They are used with disposable metal stoves that are included with field ration packs. Backpackers concerned with ultra light gear tend to make their own much lighter stove. An Esbit beverage-can stove can be made by cutting off the bottom of an aluminium soft drink can, turning it upside down to support the fuel tablet. A pot can be supported above this with a circle of chicken metal tent pegs; the burning tablets are sensitive to wind, so a simple windscreen should be used, such as a strip of aluminium foil curved in a circle around the pot and stove.
If necessary, the fuel tablet can be placed on a rock or on the dirt, with a pot supported above it by rocks, but this is less than ideal. Another common use is to provide a safe heat source for model steam engines, such as those manufactured by Wilesco and Mamod, other external combustion engines such as Stirling engines and pop pop boats. Hexamine is prepared by the reaction of ammonia. In an acid environment hexamine is converted to toxic formaldehyde, which the main hazard for toxicity is by ingestion. Fuel tablets are simple, ultra-lightweight compared to other stove options, compact; as with trioxane, hexamine has an infinite shelf life if stored properly, in a sealed dry container. However, the heat given off cannot be adjusted, so water can be boiled, but cooking requiring simmering is more difficult. Tablets are a powerful stove fuel, are sensitive to wind and dampness. Fuel tablets are expensive and are not as available compared to alternatives such as alcohol or petrol, but can use cheap stoves.
Esbit's Material Safety Data Sheet states combustion can create formaldehyde, nitrogen oxide, hydrogen cyanide and ingestion may cause nausea, gastrointestinal disturbances, kidney damage. When burned, the chemical oxidation of the fuel yields noxious fumes, which requires cooking foods in a container, such as a pot or pan, with a tight fitting lid. Burned tablets leave a sticky dark residue on the bottom of pots. If tablets are stored or used under damp conditions they can break up while burning and shed burning fragments, though this claim is hard to verify or reproduce. Hexamine is a precursor for the simplest synthesis of the chemical explosive RDX. Trioxane Metaldehyde Sterno Firelighter Esbit Compagnie GmbH website
Simplified molecular-input line-entry system
The simplified molecular-input line-entry system is a specification in the form of a line notation for describing the structure of chemical species using short ASCII strings. SMILES strings can be imported by most molecule editors for conversion back into two-dimensional drawings or three-dimensional models of the molecules; the original SMILES specification was initiated in the 1980s. It has since been extended. In 2007, an open standard called. Other linear notations include the Wiswesser line notation, ROSDAL, SYBYL Line Notation; the original SMILES specification was initiated by David Weininger at the USEPA Mid-Continent Ecology Division Laboratory in Duluth in the 1980s. Acknowledged for their parts in the early development were "Gilman Veith and Rose Russo and Albert Leo and Corwin Hansch for supporting the work, Arthur Weininger and Jeremy Scofield for assistance in programming the system." The Environmental Protection Agency funded the initial project to develop SMILES. It has since been modified and extended by others, most notably by Daylight Chemical Information Systems.
In 2007, an open standard called "OpenSMILES" was developed by the Blue Obelisk open-source chemistry community. Other'linear' notations include the Wiswesser Line Notation, ROSDAL and SLN. In July 2006, the IUPAC introduced the InChI as a standard for formula representation. SMILES is considered to have the advantage of being more human-readable than InChI; the term SMILES refers to a line notation for encoding molecular structures and specific instances should be called SMILES strings. However, the term SMILES is commonly used to refer to both a single SMILES string and a number of SMILES strings; the terms "canonical" and "isomeric" can lead to some confusion when applied to SMILES. The terms are not mutually exclusive. A number of valid SMILES strings can be written for a molecule. For example, CCO, OCC and CC all specify the structure of ethanol. Algorithms have been developed to generate the same SMILES string for a given molecule; this SMILES is unique for each structure, although dependent on the canonicalization algorithm used to generate it, is termed the canonical SMILES.
These algorithms first convert the SMILES to an internal representation of the molecular structure. Various algorithms for generating canonical SMILES have been developed and include those by Daylight Chemical Information Systems, OpenEye Scientific Software, MEDIT, Chemical Computing Group, MolSoft LLC, the Chemistry Development Kit. A common application of canonical SMILES is indexing and ensuring uniqueness of molecules in a database; the original paper that described the CANGEN algorithm claimed to generate unique SMILES strings for graphs representing molecules, but the algorithm fails for a number of simple cases and cannot be considered a correct method for representing a graph canonically. There is no systematic comparison across commercial software to test if such flaws exist in those packages. SMILES notation allows the specification of configuration at tetrahedral centers, double bond geometry; these are structural features that cannot be specified by connectivity alone and SMILES which encode this information are termed isomeric SMILES.
A notable feature of these rules is. The term isomeric SMILES is applied to SMILES in which isotopes are specified. In terms of a graph-based computational procedure, SMILES is a string obtained by printing the symbol nodes encountered in a depth-first tree traversal of a chemical graph; the chemical graph is first trimmed to remove hydrogen atoms and cycles are broken to turn it into a spanning tree. Where cycles have been broken, numeric suffix labels are included to indicate the connected nodes. Parentheses are used to indicate points of branching on the tree; the resultant SMILES form depends on the choices: of the bonds chosen to break cycles, of the starting atom used for the depth-first traversal, of the order in which branches are listed when encountered. Atoms are represented by the standard abbreviation of the chemical elements, in square brackets, such as for gold. Brackets may be omitted in the common case of atoms which: are in the "organic subset" of B, C, N, O, P, S, F, Cl, Br, or I, have no formal charge, have the number of hydrogens attached implied by the SMILES valence model, are the normal isotopes, are not chiral centers.
All other elements must be enclosed in brackets, have charges and hydrogens shown explicitly. For instance, the SMILES for water may be written as either O or. Hydrogen may be written as a separate atom; when brackets are used, the symbol H is added if the atom in brackets is bonded to one or more hydrogen, followed by the number of hydrogen atoms if greater than 1 by the sign + for a positive charge or by - for a negative charge. For example, for ammonium. If there is more than one charge, it is written as digit.
A military is a heavily-armed, highly-organised force intended for warfare known collectively as armed forces. It is officially 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, Air Force and in certain countries and Coast Guard. The main task of the military is defined as defence of the state and its interests against external armed threats. Beyond warfare, the military may be employed in additional sanctioned and non-sanctioned functions within the state, including internal security threats, population control, the promotion of a political agenda, emergency services and reconstruction, protecting corporate economic interests, social ceremonies and national honor guards. A nation's military may function as a discrete social subculture, with dedicated infrastructure such as military housing, utilities, hospitals, legal services, food production and banking services.
In broad usage, the terms "armed forces" and "military" are 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; the profession of soldiering as part of a military is older than recorded history itself. Some of the most enduring images of classical antiquity portray the power and feats of its military leaders; the Battle of Kadesh in 1274 BC was one of the defining points of Pharaoh Ramses II's reign, his monuments commemorate it in bas-relief. A thousand years the first emperor of unified China, Qin Shi Huang, was so determined to impress the gods with his military might that he had himself buried with an army of terracotta soldiers; the Romans paid considerable attention to military matters, leaving to posterity many treatises and writings on the subject, as well as a large number of lavishly carved triumphal arches and victory columns.
Issue: Possibly cognate with Thousand, cf. Latin and Romance language root word "mil-")The first recorded use of the word military in English, spelled militarie, was in 1582, it comes from the Latin militaris through French, but is of uncertain etymology, one suggestion being derived from *mil-it- – going in a body or mass. The word is now identified as denoting someone, skilled in use of weapons, or engaged in military service, or in warfare; as a noun, the military refers to a country's armed forces, or sometimes, more to the senior officers who command them. In general, it refers to the physicality of armed forces, their personnel and the physical area which they occupy; as an adjective, military referred only to soldiers and soldiering, but it soon broadened to apply to land forces in general, anything to do with their profession. The names of both the Royal Military Academy and United States Military Academy reflect this. However, at about the time of the Napoleonic Wars,'military' began to be used in reference to armed forces as a whole, in the 21st century expressions like'military service','military intelligence', and'military history' encompass naval and air force aspects.
As such, it now connotes any activity performed by armed force personnel. Military history is considered to be the history of all conflicts, not just the history of the state militaries, it differs somewhat from the history of war, with military history focusing on the people and institutions of war-making, while the history of war focuses on the evolution of war itself in the face of changing technology and geography. Military history has a number of facets. One main facet is to learn from past accomplishments and mistakes, so as to more wage war in the future. Another is to create a sense of military tradition, used to create cohesive military forces. Still, another may be to learn to prevent wars more effectively. Human knowledge about the military is based on both recorded and oral history of military conflicts, their participating armies and navies and, more air forces. There are two types of military history, although all texts have elements of both: descriptive history, that serves to chronicle conflicts without offering any statements about the causes, nature of conduct, the ending, effects of a conflict.
Despite the growing importance of military technology, military activity depends above all on people. For example, in 2000 the British Army declared: "Man is still the first weapon of war." The military organization is characterized by a strict hierarchy divided by military rank, with ranks grouped as officers, non-commissioned officers, personnel at the lowest rank. While senior officers make strategic decisions, subordinated military personnel fulfil them. Although rank titles vary by military branch and country, the rank hierarchy is common to all state armed forces worldwide. In addition to their rank, personnel occupy one of many trade roles, which are grouped according to