136-699: The PAC P-750 XSTOL , (formerly known as the PAC 750XL ) is a utility aircraft of conventional all-metal low-wing monoplane design, with fixed tricycle undercarriage . Combining the engine and wings of the PAC Cresco with a new larger fuselage and modified tail , all versions to date have been powered by a 750 hp (560 kW) Pratt & Whitney Canada PT6 turboprop . It is designed and manufactured in Hamilton, New Zealand , by Pacific Aerospace Limited . The design made its maiden flight in 2001. As with
272-491: A precipitate of aluminium hydroxide , Al(OH) 3 , forms. This is useful for clarification of water, as the precipitate nucleates on suspended particles in the water, hence removing them. Increasing the pH even further leads to the hydroxide dissolving again as aluminate , [Al(H 2 O) 2 (OH) 4 ] , is formed. Aluminium hydroxide forms both salts and aluminates and dissolves in acid and alkali, as well as on fusion with acidic and basic oxides. This behavior of Al(OH) 3
408-525: A "less classical sound". This name persisted: although the -um spelling was occasionally used in Britain, the American scientific language used -ium from the start. Most scientists throughout the world used -ium in the 19th century; and it was entrenched in several other European languages, such as French , German , and Dutch . In 1828, an American lexicographer, Noah Webster , entered only
544-499: A Swedish chemist, Jöns Jacob Berzelius , in which the name aluminium is given to the element that would be synthesized from alum. (Another article in the same journal issue also refers to the metal whose oxide is the basis of sapphire , i.e. the same metal, as to aluminium .) A January 1811 summary of one of Davy's lectures at the Royal Society mentioned the name aluminium as a possibility. The next year, Davy published
680-561: A chemistry textbook in which he used the spelling aluminum . Both spellings have coexisted since. Their usage is currently regional: aluminum dominates in the United States and Canada; aluminium is prevalent in the rest of the English-speaking world. In 1812, British scientist Thomas Young wrote an anonymous review of Davy's book, in which he proposed the name aluminium instead of aluminum , which he thought had
816-463: A counterinsurgent needs to choose two goals out of three. Relying on economic theory , this is what Zambernardi labels the "impossible trilemma" of counterinsurgency. Specifically, the impossible trilemma suggests that it is impossible to simultaneously achieve: 1) force protection, 2) distinction between enemy combatants and non-combatants, and 3) the physical elimination of insurgents. According to Zambernardi, in pursuing any two of these three goals,
952-403: A degree that victory is easy or assured for the regular forces. However, in many modern rebellions, one does not see rebel fighters working in conjunction with regular forces. Rather, they are home-grown militias or imported fighters who have no unified goals or objectives save to expel the occupier. According to Liddell Hart, there are few effective counter-measures to this strategy. So long as
1088-541: A prime example the French occupation of Spain during the Napoleonic wars . Whenever Spanish forces managed to constitute themselves into a regular fighting force, the superior French forces beat them every time. However, once dispersed and decentralized, the irregular nature of the rebel campaigns proved a decisive counter to French superiority on the battlefield. Napoleon 's army had no means of effectively combating
1224-441: A probable cause for it being soft with a low melting point and low electrical resistivity . Aluminium metal has an appearance ranging from silvery white to dull gray depending on its surface roughness . Aluminium mirrors are the most reflective of all metal mirrors for near ultraviolet and far infrared light. It is also one of the most reflective for light in the visible spectrum, nearly on par with silver in this respect, and
1360-683: A process termed passivation . Because of its general resistance to corrosion, aluminium is one of the few metals that retains silvery reflectance in finely powdered form, making it an important component of silver-colored paints. Aluminium is not attacked by oxidizing acids because of its passivation. This allows aluminium to be used to store reagents such as nitric acid , concentrated sulfuric acid , and some organic acids. In hot concentrated hydrochloric acid , aluminium reacts with water with evolution of hydrogen, and in aqueous sodium hydroxide or potassium hydroxide at room temperature to form aluminates —protective passivation under these conditions
1496-445: A reason for the insurgents to continue until victory. Trường Chinh , second in command to Ho Chi Minh of Vietnam , wrote in his Primer for Revolt : The guiding principle of the strategy for our whole resistance must be to prolong the war. To protract the war is the key to victory. Why must the war be protracted? ... If we throw the whole of our forces into a few battles to try to decide the outcome, we shall certainly be defeated and
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#17327811526591632-525: A refractory material, and in ceramics , as well as being the starting material for the electrolytic production of aluminium. Sapphire and ruby are impure corundum contaminated with trace amounts of other metals. The two main oxide-hydroxides, AlO(OH), are boehmite and diaspore . There are three main trihydroxides: bayerite , gibbsite , and nordstrandite , which differ in their crystalline structure ( polymorphs ). Many other intermediate and related structures are also known. Most are produced from ores by
1768-474: A stable noble gas configuration. Accordingly, the combined first three ionization energies of aluminium are far lower than the fourth ionization energy alone. Such an electron configuration is shared with the other well-characterized members of its group, boron , gallium , indium , and thallium ; it is also expected for nihonium . Aluminium can surrender its three outermost electrons in many chemical reactions (see below ). The electronegativity of aluminium
1904-520: A state must forgo some portion of the third objective. In particular, a state can protect its armed forces while destroying insurgents, but only by indiscriminately killing civilians as the Ottomans , Italians , and Nazis did in the Balkans, Libya, and Eastern Europe. It can choose to protect civilians along with its own armed forces instead, avoiding so-called collateral damage, but only by abandoning
2040-606: A successful counterinsurgency: In "The Three Pillars of Counterinsurgency", Dr. David Kilcullen , the Chief Strategist of the Office of the Coordinator for Counterterrorism of the U.S. State Department in 2006, described a framework for interagency cooperation in counterinsurgency operations. His pillars – Security, Political and Economic – support the overarching goal of Control, but are based on Information: This
2176-820: A variety of wet processes using acid and base. Heating the hydroxides leads to formation of corundum. These materials are of central importance to the production of aluminium and are themselves extremely useful. Some mixed oxide phases are also very useful, such as spinel (MgAl 2 O 4 ), Na-β-alumina (NaAl 11 O 17 ), and tricalcium aluminate (Ca 3 Al 2 O 6 , an important mineral phase in Portland cement ). The only stable chalcogenides under normal conditions are aluminium sulfide (Al 2 S 3 ), selenide (Al 2 Se 3 ), and telluride (Al 2 Te 3 ). All three are prepared by direct reaction of their elements at about 1,000 °C (1,800 °F) and quickly hydrolyze completely in water to yield aluminium hydroxide and
2312-575: A way of purifying bauxite to yield alumina, now known as the Bayer process , in 1889. Modern production of aluminium is based on the Bayer and Hall–Héroult processes. As large-scale production caused aluminium prices to drop, the metal became widely used in jewelry, eyeglass frames, optical instruments, tableware, and foil , and other everyday items in the 1890s and early 20th century. Aluminium's ability to form hard yet light alloys with other metals provided
2448-491: A weight-reduction programme for 2020 replaces flight-control surfaces in aluminium by composite, installs lighter seating, and strips out cabin components. The passenger and utility aircraft markets account for 70% of its sales. Financed by UK start-up Arcus Fire , the F-25 is an aerial firefighting variant, scheduled to secure its supplemental type certificate in 2021. The $ 2.2 million aircraft competes against other types like
2584-434: Is Al. Al was present in the early Solar System with abundance of 0.005% relative to Al but its half-life of 728,000 years is too short for any original nuclei to survive; Al is therefore extinct . Unlike for Al, hydrogen burning is the primary source of Al, with the nuclide emerging after a nucleus of Mg catches a free proton. However, the trace quantities of Al that do exist are the most common gamma ray emitter in
2720-407: Is paramagnetic and thus essentially unaffected by static magnetic fields. The high electrical conductivity, however, means that it is strongly affected by alternating magnetic fields through the induction of eddy currents . Aluminium combines characteristics of pre- and post-transition metals. Since it has few available electrons for metallic bonding, like its heavier group 13 congeners, it has
2856-429: Is small and highly charged ; as such, it has more polarizing power , and bonds formed by aluminium have a more covalent character. The strong affinity of aluminium for oxygen leads to the common occurrence of its oxides in nature. Aluminium is found on Earth primarily in rocks in the crust , where it is the third-most abundant element , after oxygen and silicon , rather than in the mantle , and virtually never as
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#17327811526592992-430: Is "the totality of actions aimed at defeating irregular forces ". The Oxford English Dictionary defines counterinsurgency as any "military or political action taken against the activities of guerrillas or revolutionaries" and can be considered war by a state against a non-state adversary . Insurgency and counterinsurgency campaigns have been waged since ancient history . However, modern thinking on counterinsurgency
3128-483: Is 1.61 (Pauling scale). A free aluminium atom has a radius of 143 pm . With the three outermost electrons removed, the radius shrinks to 39 pm for a 4-coordinated atom or 53.5 pm for a 6-coordinated atom. At standard temperature and pressure , aluminium atoms (when not affected by atoms of other elements) form a face-centered cubic crystal system bound by metallic bonding provided by atoms' outermost electrons; hence aluminium (at these conditions)
3264-399: Is a chemical element ; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals , about one-third that of steel . It has a great affinity towards oxygen , forming a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver , both in its color and in its great ability to reflect light. It
3400-548: Is a metal. This crystal system is shared by many other metals, such as lead and copper ; the size of a unit cell of aluminium is comparable to that of those other metals. The system, however, is not shared by the other members of its group: boron has ionization energies too high to allow metallization, thallium has a hexagonal close-packed structure, and gallium and indium have unusual structures that are not close-packed like those of aluminium and thallium. The few electrons that are available for metallic bonding in aluminium are
3536-530: Is a sociological phenomenon that constrains the habits of a military (in this case, the Nigerian military) to the long-established, yet increasingly ineffective, ideology of the offensive in irregular warfare. As Omeni writes, Whereas the Nigerian military's performance against militias in the Niger Delta already suggested the military had a poor grasp of the threat of insurgent warfare; it was further along
3672-522: Is almost never found in the elemental state; instead it is found in oxides or silicates. Feldspars , the most common group of minerals in the Earth's crust, are aluminosilicates. Aluminium also occurs in the minerals beryl , cryolite , garnet , spinel , and turquoise . Impurities in Al 2 O 3 , such as chromium and iron , yield the gemstones ruby and sapphire , respectively. Native aluminium metal
3808-488: Is also an optional 1,000 lb capacity cargo pod available which attaches to the belly of the aircraft. The aircraft can be configured as all-passenger, all-cargo or a combination of both. All variants have double cargo doors at the rear of the cabin. In February 2016, the Papua New Guinea Defence Force (PNGDF) signed an agreement to purchase four aircraft. The PNGDF purchased one P-750 for
3944-405: Is also easily machined and cast . Aluminium is an excellent thermal and electrical conductor , having around 60% the conductivity of copper , both thermal and electrical, while having only 30% of copper's density. Aluminium is capable of superconductivity , with a superconducting critical temperature of 1.2 kelvin and a critical magnetic field of about 100 gauss (10 milliteslas ). It
4080-401: Is because perception is crucial in developing control and influence over population groups. Substantive security, political and economic measures are critical but to be effective they must rest upon, and integrate with a broader information strategy. Every action in counterinsurgency sends a message; the purpose of the information campaign is to consolidate and unify this message. ... Importantly,
4216-553: Is extremely rare and can only be found as a minor phase in low oxygen fugacity environments, such as the interiors of certain volcanoes. Native aluminium has been reported in cold seeps in the northeastern continental slope of the South China Sea . It is possible that these deposits resulted from bacterial reduction of tetrahydroxoaluminate Al(OH) 4 . Although aluminium is a common and widespread element, not all aluminium minerals are economically viable sources of
PAC P-750 XSTOL - Misplaced Pages Continue
4352-536: Is greatly reduced by aqueous salts, particularly in the presence of dissimilar metals. Aluminium reacts with most nonmetals upon heating, forming compounds such as aluminium nitride (AlN), aluminium sulfide (Al 2 S 3 ), and the aluminium halides (AlX 3 ). It also forms a wide range of intermetallic compounds involving metals from every group on the periodic table. The vast majority of compounds, including all aluminium-containing minerals and all commercially significant aluminium compounds, feature aluminium in
4488-492: Is in fact more basic than that of gallium. Aluminium also bears minor similarities to the metalloid boron in the same group: AlX 3 compounds are valence isoelectronic to BX 3 compounds (they have the same valence electronic structure), and both behave as Lewis acids and readily form adducts . Additionally, one of the main motifs of boron chemistry is regular icosahedral structures, and aluminium forms an important part of many icosahedral quasicrystal alloys, including
4624-476: Is low in comparison with many other metals. All other isotopes of aluminium are radioactive . The most stable of these is Al : while it was present along with stable Al in the interstellar medium from which the Solar System formed, having been produced by stellar nucleosynthesis as well, its half-life is only 717,000 years and therefore a detectable amount has not survived since the formation of
4760-500: Is negligible. Aqua regia also dissolves aluminium. Aluminium is corroded by dissolved chlorides , such as common sodium chloride , which is why household plumbing is never made from aluminium. The oxide layer on aluminium is also destroyed by contact with mercury due to amalgamation or with salts of some electropositive metals. As such, the strongest aluminium alloys are less corrosion-resistant due to galvanic reactions with alloyed copper , and aluminium's corrosion resistance
4896-521: Is not as important. It is a polymer with the formula (AlH 3 ) n , in contrast to the corresponding boron hydride that is a dimer with the formula (BH 3 ) 2 . Aluminium's per-particle abundance in the Solar System is 3.15 ppm (parts per million). It is the twelfth most abundant of all elements and third most abundant among the elements that have odd atomic numbers, after hydrogen and nitrogen. The only stable isotope of aluminium, Al,
5032-400: Is not primarily military, but a combination of military, political and social actions under the strong control of a single authority. Galula proposes four "laws" for counterinsurgency: Galula contends that: A victory [in a counterinsurgency] is not the destruction in a given area of the insurgent's forces and his political organization. ... A victory is that plus the permanent isolation of
5168-416: Is quite soft and lacking in strength. In most applications various aluminium alloys are used instead because of their higher strength and hardness. The yield strength of pure aluminium is 7–11 MPa , while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium is ductile , with a percent elongation of 50-70%, and malleable allowing it to be easily drawn and extruded . It
5304-435: Is soft, nonmagnetic , and ductile . It has one stable isotope, Al, which is highly abundant, making aluminium the twelfth-most common element in the universe. The radioactivity of Al leads to it being used in radiometric dating . Chemically, aluminium is a post-transition metal in the boron group ; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state . The aluminium cation Al
5440-422: Is surrounded by six fluorine atoms in a distorted octahedral arrangement, with each fluorine atom being shared between the corners of two octahedra. Such {AlF 6 } units also exist in complex fluorides such as cryolite , Na 3 AlF 6 . AlF 3 melts at 1,290 °C (2,354 °F) and is made by reaction of aluminium oxide with hydrogen fluoride gas at 700 °C (1,300 °F). With heavier halides,
5576-547: Is termed amphoterism and is characteristic of weakly basic cations that form insoluble hydroxides and whose hydrated species can also donate their protons. One effect of this is that aluminium salts with weak acids are hydrolyzed in water to the aquated hydroxide and the corresponding nonmetal hydride: for example, aluminium sulfide yields hydrogen sulfide . However, some salts like aluminium carbonate exist in aqueous solution but are unstable as such; and only incomplete hydrolysis takes place for salts with strong acids, such as
PAC P-750 XSTOL - Misplaced Pages Continue
5712-416: Is that of the preceding noble gas , whereas those of its heavier congeners gallium , indium , thallium , and nihonium also include a filled d-subshell and in some cases a filled f-subshell. Hence, the inner electrons of aluminium shield the valence electrons almost completely, unlike those of aluminium's heavier congeners. As such, aluminium is the most electropositive metal in its group, and its hydroxide
5848-433: Is the eighteenth most abundant nucleus in the universe. It is created almost entirely after fusion of carbon in massive stars that will later become Type II supernovas : this fusion creates Mg, which upon capturing free protons and neutrons, becomes aluminium. Some smaller quantities of Al are created in hydrogen burning shells of evolved stars, where Mg can capture free protons. Essentially all aluminium now in existence
5984-406: Is throw overboard 99 percent of the literature on counterinsurgency, counter guerrilla, counterterrorism, and the like. Since most of it was written by the losing side, it is of little value. In examining why so many counterinsurgencies by powerful militaries fail against weaker enemies, Van Creveld identifies a key dynamic that he illustrates by the metaphor of killing a child. Regardless of whether
6120-498: The -ium spelling as primary, and they list both where it is appropriate. The production of aluminium starts with the extraction of bauxite rock from the ground. The bauxite is processed and transformed using the Bayer process into alumina , which is then processed using the Hall–Héroult process , resulting in the final aluminium. Counter-insurgency Counterinsurgency ( COIN , or NATO spelling counter-insurgency )
6256-455: The Friedel–Crafts reactions . Aluminium trichloride has major industrial uses involving this reaction, such as in the manufacture of anthraquinones and styrene ; it is also often used as the precursor for many other aluminium compounds and as a reagent for converting nonmetal fluorides into the corresponding chlorides (a transhalogenation reaction ). Aluminium forms one stable oxide with
6392-475: The London Metal Exchange , the oldest industrial metal exchange in the world, in 1978. The output continued to grow: the annual production of aluminium exceeded 50,000,000 metric tons in 2013. The real price for aluminium declined from $ 14,000 per metric ton in 1900 to $ 2,340 in 1948 (in 1998 United States dollars). Extraction and processing costs were lowered over technological progress and
6528-526: The University of Michigan . Berman, Shapiro, and Felter have outlined the modern information-centric model. In this framework, the critical determinant of counterinsurgent success is information about insurgents provided to counterinsurgents, such as insurgent locations, plans, and targets. Information can be acquired from civilian sources (human intelligence, HUMINT ), or through signals intelligence ( SIGINT ). Dr. Jeffrey Treistman previously served with
6664-475: The aluminum spelling in his American Dictionary of the English Language . In the 1830s, the -um spelling gained usage in the United States; by the 1860s, it had become the more common spelling there outside science. In 1892, Hall used the -um spelling in his advertising handbill for his new electrolytic method of producing the metal, despite his constant use of the -ium spelling in all
6800-423: The chemical formula Al 2 O 3 , commonly called alumina . It can be found in nature in the mineral corundum , α-alumina; there is also a γ-alumina phase. Its crystalline form, corundum, is very hard ( Mohs hardness 9), has a high melting point of 2,045 °C (3,713 °F), has very low volatility, is chemically inert, and a good electrical insulator, it is often used in abrasives (such as toothpaste), as
6936-584: The free metal . It is obtained industrially by mining bauxite , a sedimentary rock rich in aluminium minerals. The discovery of aluminium was announced in 1825 by Danish physicist Hans Christian Ørsted . The first industrial production of aluminium was initiated by French chemist Henri Étienne Sainte-Claire Deville in 1856. Aluminium became much more available to the public with the Hall–Héroult process developed independently by French engineer Paul Héroult and American engineer Charles Martin Hall in 1886, and
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#17327811526597072-551: The interstellar gas ; if the original Al were still present, gamma ray maps of the Milky Way would be brighter. Overall, the Earth is about 1.59% aluminium by mass (seventh in abundance by mass). Aluminium occurs in greater proportion in the Earth's crust than in the universe at large. This is because aluminium easily forms the oxide and becomes bound into rocks and stays in the Earth's crust , while less reactive metals sink to
7208-526: The 5th century BCE. The ancients are known to have used alum as a dyeing mordant and for city defense. After the Crusades , alum, an indispensable good in the European fabric industry, was a subject of international commerce; it was imported to Europe from the eastern Mediterranean until the mid-15th century. The nature of alum remained unknown. Around 1530, Swiss physician Paracelsus suggested alum
7344-825: The Air Transport Wing which was delivered in 2018. In 2023, the Australian government gifted two new P-750s to the PNGDF. A P-750 XSTOL in the markings of the North Korean state airline was photographed during the Wonsan Air Festival on September 24–25, 2016. The aircraft had been sold to China in September 2015 and then illegally exported to North Korea. Pacific Aerospace expressed surprise, however New Zealand Customs discovered that even after
7480-472: The Al–Zn–Mg class. Aluminium has a high chemical affinity to oxygen, which renders it suitable for use as a reducing agent in the thermite reaction. A fine powder of aluminium reacts explosively on contact with liquid oxygen ; under normal conditions, however, aluminium forms a thin oxide layer (~5 nm at room temperature) that protects the metal from further corrosion by oxygen, water, or dilute acid,
7616-587: The Cresco, horizontal tail surfaces presented difficulties, and these were redesigned before the type entered production. The PAC 750 received full US FAA certification in 2004. In 2008, the manufacturer stated production was increasing from 12 to 24 per year. In 2008, there was some New Zealand media criticism of government assistance for the manufacturer following cancellation of a large order. By February 2016, 100 aircraft had been produced, over 120 by Jan 2019. In 2012, Pacific Aerospace achieved certification for
7752-593: The Nigerian Army has struggled in COIN due to capabilities shortcomings, holds some merit. However, a full-spectrum analysis of the Nigeria case suggests that this popular dominant narrative scarcely scratches the surface of the true COIN challenge. This population-centered challenge, moreover, is one that militaries across the world continue to contend with. And in attempting to solve the COIN puzzle, state forces over
7888-580: The P-750 XSTOL against ICAO Annex 6 for Single Engine IFR Commercial Passenger Transport Operations. Pacific Aerospace has allowed licence production in China. A civil cargo PAC750XL UAV with minimal changes to enable remote piloting has been flown in China. This UAV is not endorsed by the New Zealand manufacturer and is a separate entity. In March 2018, Pacific Aerospace launched an updated variant,
8024-459: The P-750 XSTOL in many configurations - passenger, freight/cargo, skydive, agricultural, aerial survey and surveillance. The aircraft is marketed as excelling on rough, unpaved airstrips and is available with a wide tyre modification for this purpose. A modified version is being developed for counter-insurgency and light attack. For passenger and cargo operations, the cabin can be outfitted with up to nine passenger seats or with cargo holds. There
8160-606: The Polish PZL Dromader , targeting a 100 units market within five years. The conversion includes a new hydraulics pack, fire gate and a 300 kg (600 lb) increase in payload. The type was targeted initially to the narrow market of skydiving . In the parachuting role, the high-lift wings from the Cresco and relatively high power-to-weight ratio enable the PAC 750 to take a load of parachutists to 12,000 feet (3,700 m) and return to land in 10 minutes. A wider market
8296-545: The Super-Pac XL, with a 900 hp (670 kW) PT6A-140A up from 750 hp and a four-blade 108in (270 cm) Hartzell propeller. It competes with the Supervan 900 re-engined Cessna 208 Caravan with a 900 hp Honeywell TPE331 and 110in four-blade Hartzell propeller. A modified P-750 is ground tested, and will begin flights for a second quarter of 2018 certification and later deliveries. To increase payload,
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#17327811526598432-668: The Turkish forces off. In both the preceding cases, the insurgents and rebel fighters were working in conjunction with or in a manner complementary to regular forces. Such was also the case with the French Resistance during World War II and the National Liberation Front during the Vietnam War . The strategy in these cases is for the irregular combatant to weaken and destabilize the enemy to such
8568-418: The United States dollar, and alumina prices. The BRIC countries' combined share in primary production and primary consumption grew substantially in the first decade of the 21st century. China is accumulating an especially large share of the world's production thanks to an abundance of resources, cheap energy, and governmental stimuli; it also increased its consumption share from 2% in 1972 to 40% in 2010. In
8704-462: The United States, Western Europe, and Japan, most aluminium was consumed in transportation, engineering, construction, and packaging. In 2021, prices for industrial metals such as aluminium have soared to near-record levels as energy shortages in China drive up costs for electricity. The names aluminium and aluminum are derived from the word alumine , an obsolete term for alumina , the primary naturally occurring oxide of aluminium . Alumine
8840-578: The aluminium atoms have tetrahedral four-coordination and the other half have trigonal bipyramidal five-coordination. Four pnictides – aluminium nitride (AlN), aluminium phosphide (AlP), aluminium arsenide (AlAs), and aluminium antimonide (AlSb) – are known. They are all III-V semiconductors isoelectronic to silicon and germanium , all of which but AlN have the zinc blende structure. All four can be made by high-temperature (and possibly high-pressure) direct reaction of their component elements. Aluminium alloys well with most other metals (with
8976-436: The characteristic physical properties of a post-transition metal, with longer-than-expected interatomic distances. Furthermore, as Al is a small and highly charged cation, it is strongly polarizing and bonding in aluminium compounds tends towards covalency ; this behavior is similar to that of beryllium (Be ), and the two display an example of a diagonal relationship . The underlying core under aluminium's valence shell
9112-408: The child started the fight or how well armed the child is, an adult in a fight with a child will feel that he is acting unjustly if he harms the child and foolish if the child harms him; he will, therefore, wonder if the fight is necessary. Van Creveld argues that "by definition, a strong counterinsurgent who uses his strength to kill the members of a small, weak organization of insurgents – let alone
9248-495: The city, killing between 10-25,000 people, including many women and children. Asked by reporters what had happened, Hafez al-Assad exaggerated the damage and deaths, promoted the commanders who carried out the attacks, and razed Hama's well-known great mosque, replacing it with a parking lot. With the Muslim Brotherhood scattered, the population was so cowed that it would be years before opposition groups dared to disobey
9384-428: The civilian population by which it is surrounded, and which may lend it support – will commit crimes in an unjust cause," while "a child who is in a serious fight with an adult is justified in using every and any means available – not because he or she is right, but because he or she has no choice". Every act of insurgency becomes, from the perspective of the counterinsurgent, a reason to end the conflict, while also being
9520-741: The company was aware the aircraft was in North Korea some of the company staff had planned to sell replacement parts for the aircraft to a Chinese company. In October 2017 Pacific Aerospace pleaded guilty to three charges of planning to export aircraft parts indirectly to North Korea, and another charge relating to incorrect completion of export documentation. Data from Pacific Aerospace General characteristics Performance Related development Aircraft of comparable role, configuration, and era Aluminium Aluminium (or aluminum in North American English )
9656-419: The coordination numbers are lower. The other trihalides are dimeric or polymeric with tetrahedral four-coordinate aluminium centers. Aluminium trichloride (AlCl 3 ) has a layered polymeric structure below its melting point of 192.4 °C (378 °F) but transforms on melting to Al 2 Cl 6 dimers. At higher temperatures those increasingly dissociate into trigonal planar AlCl 3 monomers similar to
9792-428: The core. In the Earth's crust, aluminium is the most abundant metallic element (8.23% by mass ) and the third most abundant of all elements (after oxygen and silicon). A large number of silicates in the Earth's crust contain aluminium. In contrast, the Earth's mantle is only 2.38% aluminium by mass. Aluminium also occurs in seawater at a concentration of 2 μg/kg. Because of its strong affinity for oxygen, aluminium
9928-540: The decades have tried a range of tactics. Starting in the early 2000s, micro-level data has transformed the analysis of effective counterinsurgency (COIN) operations. Leading this work is the "information-centric" group of theorists and researchers, led by the work of the Empirical Studies of Conflict (ESOC) group at Princeton University , and the Conflict and Peace, Research and Development (CPRD) group at
10064-474: The decay of Al was responsible for the melting and differentiation of some asteroids after their formation 4.55 billion years ago. The remaining isotopes of aluminium, with mass numbers ranging from 21 to 43, all have half-lives well under an hour. Three metastable states are known, all with half-lives under a minute. An aluminium atom has 13 electrons, arranged in an electron configuration of [ Ne ] 3s 3p , with three electrons beyond
10200-456: The dynamics of revolutionary warfare. Counter-insurgency focuses on bridging these gaps. Insurgents take advantage of social issues known as gaps. When the gaps are wide, they create a sea of discontent, creating the environment in which the insurgent can operate. In The Insurgent Archipelago , John Mackinlay puts forward the concept of an evolution of the insurgency from the Maoist paradigm of
10336-444: The enemy will win. On the other hand, if while fighting we maintain our forces, expand them, train our army and people, learn military tactics … and at the same time wear down the enemy forces, we shall weary and discourage them in such a way that, strong as they are, they will become weak and will meet defeat instead of victory. Van Creveld thus identifies "time" as the key factor in counterinsurgency. In an attempt to find lessons from
10472-399: The environment, no living organism is known to metabolize aluminium salts , but this aluminium is well tolerated by plants and animals. Because of the abundance of these salts, the potential for a biological role for them is of interest, and studies are ongoing. Of aluminium isotopes, only Al is stable. This situation is common for elements with an odd atomic number. It is
10608-478: The exception of most alkali metals and group 13 metals) and over 150 intermetallics with other metals are known. Preparation involves heating fixed metals together in certain proportion, followed by gradual cooling and annealing . Bonding in them is predominantly metallic and the crystal structure primarily depends on efficiency of packing. There are few compounds with lower oxidation states. A few aluminium(I) compounds exist: AlF, AlCl, AlBr, and AlI exist in
10744-520: The fact that its nuclei are much lighter, while difference in the unit cell size does not compensate for this difference. The only lighter metals are the metals of groups 1 and 2 , which apart from beryllium and magnesium are too reactive for structural use (and beryllium is very toxic). Aluminium is not as strong or stiff as steel, but the low density makes up for this in the aerospace industry and for many other applications where light weight and relatively high strength are crucial. Pure aluminium
10880-494: The fault of its governors." Consequently, he advocated clemency towards the population and good governance, to seek the people's "heart and love". Liddell Hart attributed the failure of counterinsurgencies to various causes. First, as pointed out in the Insurgency addendum to the second version of his book Strategy: The Indirect Approach , a popular insurgency has an inherent advantage over any occupying force. He showed as
11016-629: The few cases of successful counterinsurgency, of which he lists two clear cases: the British efforts during The Troubles of Northern Ireland and the 1982 Hama massacre carried out by the Syrian government to suppress the Muslim Brotherhood , he asserts that the "core of the difficulty is neither military nor political, but moral" and outlines two distinct methods. The first method relies on superb intelligence, provided by those who know
11152-730: The gas phase after explosion and in stellar absorption spectra. More thoroughly investigated are compounds of the formula R 4 Al 2 which contain an Al–Al bond and where R is a large organic ligand . A variety of compounds of empirical formula AlR 3 and AlR 1.5 Cl 1.5 exist. The aluminium trialkyls and triaryls are reactive, volatile, and colorless liquids or low-melting solids. They catch fire spontaneously in air and react with water, thus necessitating precautions when handling them. They often form dimers, unlike their boron analogues, but this tendency diminishes for branched-chain alkyls (e.g. Pr , Bu , Me 3 CCH 2 ); for example, triisobutylaluminium exists as an equilibrium mixture of
11288-453: The gaseous phase when the respective trihalide is heated with aluminium, and at cryogenic temperatures. A stable derivative of aluminium monoiodide is the cyclic adduct formed with triethylamine , Al 4 I 4 (NEt 3 ) 4 . Al 2 O and Al 2 S also exist but are very unstable. Very simple aluminium(II) compounds are invoked or observed in the reactions of Al metal with oxidants. For example, aluminium monoxide , AlO, has been detected in
11424-642: The golden age of insurgency to the global insurgency of the start of the 21st century. He defines this distinction as "Maoist" and "post-Maoist" insurgency. The third Marques of Santa Cruz de Marcenado (1684–1732) is probably the earliest author who dealt systematically in his writings with counterinsurgency. In his Reflexiones Militares , published between 1726 and 1730, he discussed how to spot early signs of an incipient insurgency, prevent insurgencies, and counter them, if they could not be warded off. Strikingly, Santa Cruz recognized that insurgencies are usually due to real grievances: "A state rarely rises up without
11560-406: The government. Thus the essence of counterinsurgency warfare is summed up by Galula as "Build (or rebuild) a political machine from the population upward." Robert Grainger Ker Thompson wrote Defeating Communist Insurgency in 1966, wherein he argued that a successful counterinsurgency effort must be proactive in seizing the initiative from insurgents. Thompson outlines five basic principles for
11696-441: The grassroots. The counterinsurgent reaches a position of strength when his power is embedded in a political organization issuing from, and firmly supported by, the population. With his four principles in mind, Galula goes on to describe a general military and political strategy to put them into operation in an area that is under full insurgent control: In a Selected Area 1. Concentrate enough armed forces to destroy or to expel
11832-646: The halides, nitrate , and sulfate . For similar reasons, anhydrous aluminium salts cannot be made by heating their "hydrates": hydrated aluminium chloride is in fact not AlCl 3 ·6H 2 O but [Al(H 2 O) 6 ]Cl 3 , and the Al–O bonds are so strong that heating is not sufficient to break them and form Al–Cl bonds instead: All four trihalides are well known. Unlike the structures of the three heavier trihalides, aluminium fluoride (AlF 3 ) features six-coordinate aluminium, which explains its involatility and insolubility as well as high heat of formation . Each aluminium atom
11968-443: The information campaign has to be conducted at a global, regional and local level — because modern insurgents draw upon global networks of sympathy, support, funding and recruitment. Kilcullen considers the three pillars to be of equal importance because unless they are developed in parallel, the campaign becomes unbalanced: too much economic assistance with inadequate security, for example, simply creates an array of soft targets for
12104-453: The institution of COIN within militaries and their tendency to reject the innovation and adaptation often necessary to defeat insurgency. These three features, furthermore, influence and can undermine the operational tactics and concepts adopted against insurgents. The COIN challenge, therefore, is not just operational; it also is cultural and institutional before ever it reflects on the battlefield. According to Omeni, institutional isomorphism
12240-485: The insurgency maintains popular support, it will retain all of its strategic advantages of mobility, invisibility, and legitimacy in its own eyes and the eyes of the people. So long as this is the situation, an insurgency essentially cannot be defeated by regular forces. David Galula gained his practical experience in counterinsurgency as a French Army officer in the Algerian War . His theory of counterinsurgency
12376-456: The insurgent from the population, isolation not enforced upon the population, but maintained by and with the population. ... In conventional warfare, strength is assessed according to military or other tangible criteria, such as the number of divisions, the position they hold, the industrial resources, etc. In revolutionary warfare, strength must be assessed by the extent of support from the population as measured in terms of political organization at
12512-471: The insurgents. Similarly, too much security assistance without political consensus or governance simply creates more capable armed groups. In developing each pillar, we measure progress by gauging effectiveness (capability and capacity) and legitimacy (the degree to which the population accepts that government actions are in its interest). The overall goal, according to this model, "is not to reduce violence to zero or to kill every insurgent, but rather to return
12648-451: The line, as the military struggled against Boko Haram's threat, that the extent of this weakness was exposed. At best, the utility of force, for the Nigerian military, had become but a temporary solution against the threat of insurgent warfare. At worst, the existing model has been perpetuated at such high cost, that urgent revisionist thinking around the idea of counterinsurgency within the military institution may now be required. Additionally,
12784-433: The low-pressure polymerization of ethene and propene . There are also some heterocyclic and cluster organoaluminium compounds involving Al–N bonds. The industrially most important aluminium hydride is lithium aluminium hydride (LiAlH 4 ), which is used as a reducing agent in organic chemistry . It can be produced from lithium hydride and aluminium trichloride . The simplest hydride, aluminium hydride or alane,
12920-531: The main body of armed insurgents. 2. Detach for the area sufficient troops to oppose an insurgent come back in strength, install these troops in the hamlets, villages, and towns where the population lives. 3. Establish contact with the population, control its movements in order to cut off its links with the guerrillas. 4. Destroy the local insurgent political organization. 5. Set up, by means of elections, new provisional local authorities. 6. Test those authorities by assigning them various concrete tasks. Replace
13056-526: The manufacturer claims lower single-engine running costs than many other utility types, for example, the twin-engined DHC-6 Twin Otter , the type has less usable volume (large cargo panniers providing a partial solution). Due to the unique wing design the P-750 is capable of carrying a higher payload than the larger Cessna 208 Caravan. The aircraft is currently marketed as the P-750 XSTOL. Pacific Aerospace offers
13192-445: The margins of the theoretical debate – even though Africa today is faced with a number of deadly insurgencies. In Counter-insurgency in Nigeria , Omeni, a Nigerian academic, discusses the interactions between certain features away from the battlefield, which account for battlefield performance against insurgent warfare. Specifically, Omeni argues that the trio of historical experience, organisational culture (OC) and doctrine, help explain
13328-512: The mass production of aluminium led to its extensive use in industry and everyday life. In the First and Second World Wars, aluminium was a crucial strategic resource for aviation . In 1954, aluminium became the most produced non-ferrous metal , surpassing copper . In the 21st century, most aluminium was consumed in transportation, engineering, construction, and packaging in the United States, Western Europe, and Japan. Despite its prevalence in
13464-529: The metal remained rare; its cost exceeded that of gold. The first industrial production of aluminium was established in 1856 by French chemist Henri Etienne Sainte-Claire Deville and companions. Deville had discovered that aluminium trichloride could be reduced by sodium, which was more convenient and less expensive than potassium, which Wöhler had used. Even then, aluminium was still not of great purity and produced aluminium differed in properties by sample. Because of its electricity-conducting capacity, aluminium
13600-655: The metal to be isolated from alum was alumium , which Davy suggested in an 1808 article on his electrochemical research, published in Philosophical Transactions of the Royal Society . It appeared that the name was created from the English word alum and the Latin suffix -ium ; but it was customary then to give elements names originating in Latin, so this name was not adopted universally. This name
13736-465: The metal with many uses at the time. During World War I , major governments demanded large shipments of aluminium for light strong airframes; during World War II , demand by major governments for aviation was even higher. By the mid-20th century, aluminium had become a part of everyday life and an essential component of housewares. In 1954, production of aluminium surpassed that of copper , historically second in production only to iron, making it
13872-491: The metal. Almost all metallic aluminium is produced from the ore bauxite (AlO x (OH) 3–2 x ). Bauxite occurs as a weathering product of low iron and silica bedrock in tropical climatic conditions. In 2017, most bauxite was mined in Australia, China, Guinea, and India. The history of aluminium has been shaped by usage of alum . The first written record of alum, made by Greek historian Herodotus , dates back to
14008-418: The military's decisive civil war victory, the pivot in Nigeria's strategic culture towards a regional role, and the institutional delegitimization brought about by decades of coups and political meddling, meant that much time went by without substantive revisionism to the military's thinking around its internal function. Change moreover, where it occurred, was institutionally isomorphic and not as far removed from
14144-609: The military's own origins as the intervening decades may have suggested. Further, the infantry-centric nature of the Nigerian Army 's battalions, traceable back to the Nigerian Civil War back in the 1960s, is reflected in the kinetic nature of the Army's contemporary COIN approach. This approach has failed to defeat Boko Haram in the way many expected. Certainly, therefore, the popular argument today, which holds that
14280-485: The monomer and dimer. These dimers, such as trimethylaluminium (Al 2 Me 6 ), usually feature tetrahedral Al centers formed by dimerization with some alkyl group bridging between both aluminium atoms. They are hard acids and react readily with ligands, forming adducts. In industry, they are mostly used in alkene insertion reactions, as discovered by Karl Ziegler , most importantly in "growth reactions" that form long-chain unbranched primary alkenes and alcohols, and in
14416-506: The most produced non-ferrous metal . During the mid-20th century, aluminium emerged as a civil engineering material, with building applications in both basic construction and interior finish work, and increasingly being used in military engineering, for both airplanes and land armor vehicle engines. Earth's first artificial satellite , launched in 1957, consisted of two separate aluminium semi-spheres joined and all subsequent space vehicles have used aluminium to some extent. The aluminium can
14552-428: The natural and artificial environment of the conflict as well as the insurgents. Once such superior intelligence is gained, the counterinsurgents must be trained to a point of high professionalism and discipline such that they will exercise discrimination and restraint. Through such discrimination and restraint, the counterinsurgents do not alienate members of the populace besides those already fighting them, while delaying
14688-614: The next decade, the -um spelling dominated American usage. In 1925, the American Chemical Society adopted this spelling. The International Union of Pure and Applied Chemistry (IUPAC) adopted aluminium as the standard international name for the element in 1990. In 1993, they recognized aluminum as an acceptable variant; the most recent 2005 edition of the IUPAC nomenclature of inorganic chemistry also acknowledges this spelling. IUPAC official publications use
14824-401: The objective of destroying the insurgents. Finally, a state can discriminate between combatants and non-combatants while killing insurgents, but only by increasing the risks for its own troops, because often insurgents will hide behind civilians, or appear to be civilians. So a country must choose two out of three goals and develop a strategy that can successfully accomplish them while sacrificing
14960-429: The only primordial aluminium isotope, i.e. the only one that has existed on Earth in its current form since the formation of the planet. It is therefore a mononuclidic element and its standard atomic weight is virtually the same as that of the isotope. This makes aluminium very useful in nuclear magnetic resonance (NMR), as its single stable isotope has a high NMR sensitivity. The standard atomic weight of aluminium
15096-472: The overall system to normality — noting that 'normality' in one society may look different from normality in another. In each case, we seek not only to establish control, but also to consolidate that control and then transfer it to permanent, effective, and legitimate institutions." Military historian Martin van Creveld , noting that almost all attempts to deal with insurgency have ended in failure, advises: The first, and absolutely indispensable, thing to do
15232-407: The oxidation state 3+. The coordination number of such compounds varies, but generally Al is either six- or four-coordinate. Almost all compounds of aluminium(III) are colorless. In aqueous solution, Al exists as the hexaaqua cation [Al(H 2 O) 6 ] , which has an approximate K a of 10 . Such solutions are acidic as this cation can act as a proton donor and progressively hydrolyze until
15368-460: The patents he filed between 1886 and 1903. It is unknown whether this spelling was introduced by mistake or intentionally, but Hall preferred aluminum since its introduction because it resembled platinum , the name of a prestigious metal. By 1890, both spellings had been common in the United States, the -ium spelling being slightly more common; by 1895, the situation had reversed; by 1900, aluminum had become twice as common as aluminium ; in
15504-555: The people as the fish swims in the sea. –Aphorism based on the writing of Mao Zedong Counterinsurgency is normally conducted as a combination of conventional military operations and other means, such as demoralization in the form of propaganda , Psy-ops , and assassinations . Counter-insurgency operations include many different facets: military , paramilitary , political , economic , psychological , and civic actions taken to defeat insurgency . To understand counterinsurgency, one must understand insurgency to comprehend
15640-404: The planet. However, minute traces of Al are produced from argon in the atmosphere by spallation caused by cosmic ray protons. The ratio of Al to Be has been used for radiodating of geological processes over 10 to 10 year time scales, in particular transport, deposition, sediment storage, burial times, and erosion. Most meteorite scientists believe that the energy released by
15776-635: The rebels, and in the end, their strength and morale were so sapped that when Wellington was finally able to challenge French forces in the field, the French had almost no choice but to abandon the situation. Counterinsurgency efforts may be successful, especially when the insurgents are unpopular. The Philippine–American War , the Shining Path in Peru, and the Malayan Emergency have been
15912-537: The regime again and, van Creveld argues, the massacre most likely saved the regime and prevented a bloody civil war . Van Creveld condenses al-Assad's strategy into five rules while noting that they could easily have been written by Niccolò Machiavelli : In "Counterinsurgency's Impossible Trilemma", Dr. Lorenzo Zambernardi, an Italian academic now working in the United States, clarifies the tradeoffs involved in counterinsurgency operations. He argues that counterinsurgency involves three main goals, but in real practice,
16048-423: The respective hydrogen chalcogenide . As aluminium is a small atom relative to these chalcogens, these have four-coordinate tetrahedral aluminium with various polymorphs having structures related to wurtzite , with two-thirds of the possible metal sites occupied either in an orderly (α) or random (β) fashion; the sulfide also has a γ form related to γ-alumina, and an unusual high-temperature hexagonal form where half
16184-485: The scale of the economies. However, the need to exploit lower-grade poorer quality deposits and the use of fast increasing input costs (above all, energy) increased the net cost of aluminium; the real price began to grow in the 1970s with the rise of energy cost. Production moved from the industrialized countries to countries where production was cheaper. Production costs in the late 20th century changed because of advances in technology, lower energy prices, exchange rates of
16320-541: The second method exemplified by the Hama massacre . In 1982, the regime of Syrian president Hafez al-Assad was on the point of being overwhelmed by the countrywide insurgency of the Muslim Brotherhood . Al-Assad sent a Syrian Army division under his brother Rifaat to the city of Hama , known to be the center of the resistance. Following a counterattack by the Brotherhood, Rifaat used his heavy artillery to demolish
16456-634: The sites of failed insurgencies. Hart also points to the experiences of T. E. Lawrence and the Arab Revolt during World War I as another example of the power of the rebel/insurgent. Though the Ottomans often had advantages in manpower of more than 100 to 1, the Arabs ' ability to materialize out of the desert, strike, and disappear again often left the Turks reeling and paralyzed, creating an opportunity for regular British forces to sweep in and finish
16592-408: The softs and the incompetents, give full support to the active leaders. Organize self-defense units. 7. Group and educate the leaders in a national political movement. 8. Win over or suppress the last insurgent remnants. According to Galula, some of these steps can be skipped in areas that are only partially under insurgent control, and most of them are unnecessary in areas already controlled by
16728-408: The structure of BCl 3 . Aluminium tribromide and aluminium triiodide form Al 2 X 6 dimers in all three phases and hence do not show such significant changes of properties upon phase change. These materials are prepared by treating aluminium with the halogen. The aluminium trihalides form many addition compounds or complexes; their Lewis acidic nature makes them useful as catalysts for
16864-680: The struggle in Northern Ireland had cost the United Kingdom three thousand fatal casualties. Of the three thousand, about seventeen hundred were civilians...of the remaining, a thousand were British soldiers. No more than three hundred were terrorists, a ratio of three to one. If the prerequisites for the first method – excellent intelligence, superbly trained and disciplined soldiers and police, and an iron will to avoid being provoked into lashing out – are lacking, van Creveld posits that counterinsurgents who still want to win must use
17000-462: The third objective. Zambernardi's theory posits that to protect populations, which is necessary to defeat insurgencies and to physically destroy an insurgency, the counterinsurgent's military forces must be sacrificed, risking the loss of domestic political support. Another writer who explores a trio of features relevant to understanding counterinsurgency is Akali Omeni. Within the contemporary context, COIN warfare by African militaries tends to be at
17136-461: The time when the counterinsurgents become disgusted by their own actions and demoralized. General Patrick Walters, the British commander of troops in Northern Ireland, explicitly stated that his objective was not to kill as many terrorists as possible but to ensure that as few people on both sides were killed. In the vast majority of counterinsurgencies, the "forces of order" kill far more people than they lose. In contrast and using very rough figures,
17272-536: The two therefore look similar. Aluminium is also good at reflecting solar radiation , although prolonged exposure to sunlight in air adds wear to the surface of the metal; this may be prevented if aluminium is anodized , which adds a protective layer of oxide on the surface. The density of aluminium is 2.70 g/cm , about 1/3 that of steel, much lower than other commonly encountered metals, making aluminium parts easily identifiable through their lightness. Aluminium's low density compared to most other metals arises from
17408-461: Was a salt of an earth of alum. In 1595, German doctor and chemist Andreas Libavius experimentally confirmed this. In 1722, German chemist Friedrich Hoffmann announced his belief that the base of alum was a distinct earth. In 1754, German chemist Andreas Sigismund Marggraf synthesized alumina by boiling clay in sulfuric acid and subsequently adding potash . Attempts to produce aluminium date back to 1760. The first successful attempt, however,
17544-494: Was borrowed from French, which in turn derived it from alumen , the classical Latin name for alum , the mineral from which it was collected. The Latin word alumen stems from the Proto-Indo-European root *alu- meaning "bitter" or "beer". British chemist Humphry Davy , who performed a number of experiments aimed to isolate the metal, is credited as the person who named the element. The first name proposed for
17680-422: Was completed in 1824 by Danish physicist and chemist Hans Christian Ørsted . He reacted anhydrous aluminium chloride with potassium amalgam , yielding a lump of metal looking similar to tin. He presented his results and demonstrated a sample of the new metal in 1825. In 1827, German chemist Friedrich Wöhler repeated Ørsted's experiments but did not identify any aluminium. (The reason for this inconsistency
17816-443: Was criticized by contemporary chemists from France, Germany, and Sweden, who insisted the metal should be named for the oxide, alumina, from which it would be isolated. The English name alum does not come directly from Latin, whereas alumine / alumina obviously comes from the Latin word alumen (upon declension , alumen changes to alumin- ). One example was Essai sur la Nomenclature chimique (July 1811), written in French by
17952-467: Was developed during decolonization . During insurgency and counterinsurgency, the distinction between civilians and combatants is often blurred. Counterinsurgency may involve attempting to win the hearts and minds of populations supporting the insurgency. Alternatively, it may be waged in an attempt to intimidate or eliminate civilian populations suspected of loyalty to the insurgency through indiscriminate violence. The guerrilla must swim in
18088-418: Was invented in 1956 and employed as a storage for drinks in 1958. Throughout the 20th century, the production of aluminium rose rapidly: while the world production of aluminium in 1900 was 6,800 metric tons, the annual production first exceeded 100,000 metric tons in 1916; 1,000,000 tons in 1941; 10,000,000 tons in 1971. In the 1970s, the increased demand for aluminium made it an exchange commodity; it entered
18224-433: Was only discovered in 1921.) He conducted a similar experiment in the same year by mixing anhydrous aluminium chloride with potassium and produced a powder of aluminium. In 1845, he was able to produce small pieces of the metal and described some physical properties of this metal. For many years thereafter, Wöhler was credited as the discoverer of aluminium. As Wöhler's method could not yield great quantities of aluminium,
18360-570: Was subsequently sought, and examples have been sold for use in utility roles, including freight, agricultural applications , passenger operations, aerial photography and surveying. Twelve aircraft have now been extensively modified for geo-survey work , being fitted with a magnetic anomaly detector sting tail. Proposed ski and float conversions have yet to fly. The P-750 XSTOL is used in South Africa by NatureLink on United Nations Humanitarian Air Services / World Food Programme contracts. While
18496-580: Was used as the cap of the Washington Monument , completed in 1885. The tallest building in the world at the time, the non-corroding metal cap was intended to serve as a lightning rod peak. The first industrial large-scale production method was independently developed in 1886 by French engineer Paul Héroult and American engineer Charles Martin Hall ; it is now known as the Hall–Héroult process . The Hall–Héroult process converts alumina into metal. Austrian chemist Carl Joseph Bayer discovered
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