Clay is a finely-grained natural rock or soil material that combines one or more clay minerals with possible traces of quartz, metal oxides and organic matter. Geologic clay deposits are composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure. Clays are plastic due to particle size and geometry as well as water content, become hard and non–plastic upon drying or firing. Depending on the soil's content in which it is found, clay can appear in various colours from white to dull grey or brown to deep orange-red. Although many occurring deposits include both silts and clay, clays are distinguished from other fine-grained soils by differences in size and mineralogy. Silts, which are fine-grained soils that do not include clay minerals, tend to have larger particle sizes than clays. There is, some overlap in particle size and other physical properties; the distinction between silt and clay varies by discipline. Geologists and soil scientists consider the separation to occur at a particle size of 2 µm, sedimentologists use 4–5 μm, colloid chemists use 1 μm.
Geotechnical engineers distinguish between silts and clays based on the plasticity properties of the soil, as measured by the soils' Atterberg limits. ISO 14688 grades clay particles as being smaller than 2 silt particles as being larger. Mixtures of sand and less than 40% clay are called loam. Loam is used as a building material. Clay minerals form over long periods of time as a result of the gradual chemical weathering of rocks silicate-bearing, by low concentrations of carbonic acid and other diluted solvents; these solvents acidic, migrate through the weathering rock after leaching through upper weathered layers. In addition to the weathering process, some clay minerals are formed through hydrothermal activity. There are two types of clay deposits: secondary. Primary clays remain at the site of formation. Secondary clays are clays that have been transported from their original location by water erosion and deposited in a new sedimentary deposit. Clay deposits are associated with low energy depositional environments such as large lakes and marine basins.
Depending on the academic source, there are three or four main groups of clays: kaolinite, montmorillonite-smectite and chlorite. Chlorites are not always considered to be a clay, sometimes being classified as a separate group within the phyllosilicates. There are 30 different types of "pure" clays in these categories, but most "natural" clay deposits are mixtures of these different types, along with other weathered minerals. Varve is clay with visible annual layers, which are formed by seasonal deposition of those layers and are marked by differences in erosion and organic content; this type of deposit is common in former glacial lakes. When fine sediments are delivered into the calm waters of these glacial lake basins away from the shoreline, they settle to the lake bed; the resulting seasonal layering is preserved in an distribution of clay sediment banding. Quick clay is a unique type of marine clay indigenous to the glaciated terrains of Norway, Northern Ireland, Sweden, it is a sensitive clay, prone to liquefaction, involved in several deadly landslides.
Powder X-ray diffraction can be used to identify clays. The physical and reactive chemical properties can be used to help elucidate the composition of clays. Clays exhibit plasticity. However, when dry, clay becomes firm and when fired in a kiln, permanent physical and chemical changes occur; these changes convert the clay into a ceramic material. Because of these properties, clay is used for making pottery, both utilitarian and decorative, construction products, such as bricks and floor tiles. Different types of clay, when used with different minerals and firing conditions, are used to produce earthenware and porcelain. Prehistoric humans discovered the useful properties of clay; some of the earliest pottery shards recovered are from Japan. They are associated with the Jōmon culture and deposits they were recovered from have been dated to around 14,000 BC. Clay tablets were the first known writing medium. Scribes wrote by inscribing them with cuneiform script using a blunt reed called a stylus. Purpose-made clay balls were used as sling ammunition.
Clays sintered in fire were the first form of ceramic. Bricks, cooking pots, art objects, smoking pipes, musical instruments such as the ocarina can all be shaped from clay before being fired. Clay is used in many industrial processes, such as paper making, cement production, chemical filtering; until the late 20th century, bentonite clay was used as a mold binder in the manufacture of sand castings. Clay, being impermeable to water, is used where natural seals are needed, such as in the cores of dams, or as a barrier in landfills against toxic seepage. Studies in the early 21st century have investigated clay's absorption capacities in various applications, such as the removal of heavy metals from waste water and air purification. Traditional uses of clay as medicine goes back to prehistoric times. An example is Armenian bole, used to soothe an upset stomach; some animals such as parrots and pigs ingest clay for similar reasons. Kaolin clay and attapulgite have been used as anti-diarrheal medicines.
Clay as the defining ingredient of loam is one of the oldest building materials on Earth, among other
Glass is a non-crystalline, amorphous solid, transparent and has widespread practical and decorative uses in, for example, window panes and optoelectronics. The most familiar, the oldest, types of manufactured glass are "silicate glasses" based on the chemical compound silica, the primary constituent of sand; the term glass, in popular usage, is used to refer only to this type of material, familiar from use as window glass and in glass bottles. Of the many silica-based glasses that exist, ordinary glazing and container glass is formed from a specific type called soda-lime glass, composed of 75% silicon dioxide, sodium oxide from sodium carbonate, calcium oxide called lime, several minor additives. Many applications of silicate glasses derive from their optical transparency, giving rise to their primary use as window panes. Glass will transmit and refract light. Glass can be coloured by adding metallic salts, can be painted and printed with vitreous enamels; these qualities have led to the extensive use of glass in the manufacture of art objects and in particular, stained glass windows.
Although brittle, silicate glass is durable, many examples of glass fragments exist from early glass-making cultures. Because glass can be formed or moulded into any shape, it has been traditionally used for vessels: bowls, bottles and drinking glasses. In its most solid forms it has been used for paperweights and beads; when extruded as glass fiber and matted as glass wool in a way to trap air, it becomes a thermal insulating material, when these glass fibers are embedded into an organic polymer plastic, they are a key structural reinforcement part of the composite material fiberglass. Some objects were so made of silicate glass that they are called by the name of the material, such as drinking glasses and eyeglasses. Scientifically, the term "glass" is defined in a broader sense, encompassing every solid that possesses a non-crystalline structure at the atomic scale and that exhibits a glass transition when heated towards the liquid state. Porcelains and many polymer thermoplastics familiar from everyday use are glasses.
These sorts of glasses can be made of quite different kinds of materials than silica: metallic alloys, ionic melts, aqueous solutions, molecular liquids, polymers. For many applications, like glass bottles or eyewear, polymer glasses are a lighter alternative than traditional glass. Silicon dioxide is a common fundamental constituent of glass. In nature, vitrification of quartz occurs when lightning strikes sand, forming hollow, branching rootlike structures called fulgurites. Fused quartz is a glass made from chemically-pure silica, it has excellent resistance to thermal shock, being able to survive immersion in water while red hot. However, its high melting temperature and viscosity make it difficult to work with. Other substances are added to simplify processing. One is sodium carbonate; the soda makes the glass water-soluble, undesirable, so lime, some magnesium oxide and aluminium oxide are added to provide for a better chemical durability. The resulting glass is called a soda-lime glass. Soda-lime glasses account for about 90% of manufactured glass.
Most common glass contains other ingredients to change its properties. Lead glass or flint glass is more "brilliant" because the increased refractive index causes noticeably more specular reflection and increased optical dispersion. Adding barium increases the refractive index. Thorium oxide gives glass a high refractive index and low dispersion and was used in producing high-quality lenses, but due to its radioactivity has been replaced by lanthanum oxide in modern eyeglasses. Iron can be incorporated into glass to absorb infrared radiation, for example in heat-absorbing filters for movie projectors, while cerium oxide can be used for glass that absorbs ultraviolet wavelengths; the following is a list of the more common types of silicate glasses and their ingredients and applications: Fused quartz called fused-silica glass, vitreous-silica glass: silica in vitreous, or glass, form. It has low thermal expansion, is hard, resists high temperatures, it is the most resistant against weathering. Fused quartz is used for high-temperature applications such as furnace tubes, lighting tubes, melting crucibles, etc.
Soda-lime-silica glass, window glass: silica + sodium oxide + lime + magnesia + alumina. Is transparent formed and most suitable for window glass, it has a high thermal expansion and poor resistance to heat. It is used for windows, some low-temperature incandescent light bulbs, tableware. Container glass is a soda-lime glass, a slight variation on flat glass, which uses more alumina and calcium, less sodium and magnesium, which are more water-soluble; this makes it less susceptible to water erosion. Sodium borosilicate glass, Pyrex: silica + boron trioxide + soda + alumina. Stan
Belgian Land Component
The Land Component is the land branch of the Belgian Armed Forces. The current chief of staff of the Land Component is Major-General Marc Thys. For a detailed history of the Belgian Army from 1830 to post 1945 see Belgian Armed Forces. Ranks in use by the Belgian Army are listed at Belgian military ranks. According to the Law of 16 August 1873, the army was to consist of: 14 regiments of line infantry 3 regiments of Jäger 1 regiment of grenadiers 1 regiment of Carabinier 2 companies settled 1 discipline body 1 school of children troopNote: a battalion consists of four companies of 216 men 4 regiments of lancers 2 regiments of guides 2 regiments of Chasseur Note: a squadron had 130 horses 4 regiments of artillery 3 regiments of fortress artillery or siege artillery 1 pontoon company 1 company of artificers 1 company of gunsmiths 1 company of artillery workersNote: A battery has 6 guns 1 Engineer Regiment 1 railway company 1 campaign Telegraph company 1 telegraph room company 1 pontoon room company 1 workers company 7 train companies A major reorganisation of the army had been authorised by the government in 1912, providing for a total army of 350,000 men by 1926 - 150,000 in the field forces, 130,000 in fortress garrisons and 70,000 reserves and auxiliaries.
At the outbreak of war this reorganisation was nowhere near complete and only 117,000 men could be mobilised for the field forces, with the other branches deficient. The Commander-in-Chief was King Albert I, with Lieutenant-General Chevalier Antonin de Selliers de Moranville as the Chief of the General Staff from 25 May 1914 until 6 September 1914 when a Royal Decree abolished the function of Chief of Staff of the army. In this way the King secured his control of the command. 1st Division - around Ghent. 2nd Division - Antwerp. 3rd Division - around Liège. 4th Division - Namur and Charleroi. 5th Division - around Mons. 6th Division - Brussels. Cavalry Division - Brussels. In addition, there were garrisons at Antwerp, Liège and Namur, each placed under the command of the local divisional commander; each division contained three mixed brigades, one cavalry regiment, one artillery regiment, as well as various support units. Each infantry regiment contained three battalions, with one regiment in each brigade having a machine-gun company of six guns.
An artillery regiment had three batteries of four guns. The nominal strength of a division varied from 25,500 to 32,000 all ranks, with a total strength of eighteen infantry battalions, a cavalry regiment, eighteen machine-guns, forty-eight guns. Two divisions each had an additional artillery regiment, for a total of sixty guns; the Cavalry Division had two brigades of two regiments each, three horse artillery batteries, a cyclist battalion, along with support units. In 1940, the King of Belgium was the commander in chief of the Belgian Army which had 100,000 active duty personnel; the army was composed of seven infantry corps, that were garrisoned at Brussels and Liege, two divisions of partially-mechanised cavalry Corps at Brussels and the Ardenne. The Corps were as follows: I Corps with the 1st, 4th, 7th Infantry Divisions II Corps with the 6th, 11th, 14th Infantry Divisions III Corps with the 1st Chasseurs Ardennais and the 2nd and 3rd Infantry Divisions IV Corps with the 9th, 15th, 18th Infantry Divisions V Corps with three divisions VI Corps with three divisionsEach Army Corps had its own headquarters staff, two active and several reserve Infantry Divisions, Corps Artillery Regiment of four battalions of two batteries with 16 artillery pieces per battalion, a Pioneer regiment.
Each infantry divisions had a divisional staff along with three infantry regiments, each of 3,000 men. Each regiment had 108 light machine guns, 52 heavy machine guns, nine heavy mortars or infantry gun howitzers, plus six antitank guns. Within the Free Belgian Forces that were formed in Great Britain during the occupation of Belgium between 1940–45, there was a land force formation, the 1st Belgian Infantry Brigade. An additional three divisions were raised and trained in Northern Ireland, but the war ended before they could see action. However, they joined the initial Belgian occupation force in Germany, I Belgian Corps, whose headquarters moved to Luedenscheid in October 1946. Of the 75,000 troops that found themselves in Germany on 8 May 1945, the vast majority had been recruited after the liberation of Belgium. During the Cold War, Belgium provided the I Belgian Corps, consisting of the 1st Infantry Division in Liège and 16th Mechanised Division in Neheim-Hüsten, to NATO's Northern Army Group for the defence of West Germany.
There were two reserve brigade
Cameroon the Republic of Cameroon, is a country in Central Africa. It is bordered by Nigeria to the north. Cameroon's coastline lies on the Bight of part of the Gulf of Guinea and the Atlantic Ocean. Although Cameroon is not an ECOWAS member state, it is geographically and in West Africa with the Southern Cameroons which now form her Northwest and Southwest Regions having a strong West African history; the country is sometimes identified as West African and other times as Central African due to its strategic position at the crossroads between West and Central Africa. French and English are the official languages of Cameroon; the country is referred to as "Africa in miniature" for its geological and cultural diversity. Natural features include beaches, mountains and savannas; the highest point at 4,100 metres is Mount Cameroon in the Southwest Region of the country, the largest cities in population-terms are Douala on the Wouri river, its economic capital and main seaport, Yaoundé, its political capital, Garoua.
The country is well known for its native styles of music makossa and bikutsi, for its successful national football team. Early inhabitants of the territory included the Sao civilisation around Lake Chad and the Baka hunter-gatherers in the southeastern rainforest. Portuguese explorers reached the coast in the 15th century and named the area Rio dos Camarões, which became Cameroon in English. Fulani soldiers founded the Adamawa Emirate in the north in the 19th century, various ethnic groups of the west and northwest established powerful chiefdoms and fondoms. Cameroon became a German colony in 1884 known as Kamerun. After World War I, the territory was divided between France and the United Kingdom as League of Nations mandates; the Union des Populations du Cameroun political party advocated independence, but was outlawed by France in the 1950s, leading to the Bamileke War fought between French and UPC militant forces until early 1971. In 1960, the French-administered part of Cameroon became independent as the Republic of Cameroun under President Ahmadou Ahidjo.
The southern part of British Cameroons federated with it in 1961 to form the Federal Republic of Cameroon. The federation was abandoned in 1972; the country was renamed the United Republic of Cameroon in 1972 and the Republic of Cameroon in 1984. Large numbers of Cameroonians live as subsistence farmers. Since 1982 Paul Biya has been President, governing with his Cameroon People's Democratic Movement party; the country has experienced tensions coming from the English-speaking territories. Politicians in the English-speaking regions have advocated for greater decentralisation and complete separation or independence from Cameroon. In 2017, tensions in the English-speaking territories escalated into open warfare; the territory of present-day Cameroon was first settled during the Neolithic Era. The longest continuous inhabitants are groups such as the Baka. From here, Bantu migrations into eastern and central Africa are believed to have originated about 2,000 years ago; the Sao culture arose around Lake Chad, c. 500 AD, gave way to the Kanem and its successor state, the Bornu Empire.
Kingdoms and chiefdoms arose in the west. Portuguese sailors reached the coast in 1472, they noted an abundance of the ghost shrimp Lepidophthalmus turneranus in the Wouri River and named it Rio dos Camarões, which became Cameroon in English. Over the following few centuries, European interests regularised trade with the coastal peoples, Christian missionaries pushed inland. In the early 19th century, Modibo Adama led Fulani soldiers on a jihad in the north against non-Muslim and Muslim peoples and established the Adamawa Emirate. Settled peoples who fled the Fulani caused a major redistribution of population; the Bamum tribe have a writing system, known as Shu Mom. The script was given to them by Sultan Ibrahim Njoya in 1896, is taught in Cameroon by the Bamum Scripts and Archives Project. Germany began to establish roots in Cameroon in 1868 when the Woermann Company of Hamburg built a warehouse, it was built on the estuary of the Wouri River. Gustav Nachtigal made a treaty with one of the local kings to annex the region for the German emperor.
The German Empire claimed the territory as the colony of Kamerun in 1884 and began a steady push inland. The Germans ran into resistance with the native people who did not want the Germans to establish themselves on this land. Under the influence of Germany, commercial companies were left to regulate local administrations; these concessions used forced labour of the Africans to make a profit. The labour was used on banana, palm oil, cocoa plantations, they initiated projects to improve the colony's infrastructure, relying on a harsh system of forced labour, much criticised by the other colonial powers. With the defeat of Germany in World War I, Kamerun became a League of Nations mandate territory and was split into French Cameroons and British Cameroons in 1919. France integrated the economy of Cameroon with that of France and improved the infrastructure with capital investments and skilled workers, modifying the system of forced labour; the British administered their territory from neighbouring Nigeria.
Natives complained that this made them a neglected "colony of a colony". Nigerian migrant workers flocked to Southern Cameroons, ending forced labour altogether but angering the local natives, who felt swamped. T
Sugarcane, or sugar cane, are several species of tall perennial true grasses of the genus Saccharum, tribe Andropogoneae, native to the warm temperate to tropical regions of South, Southeast Asia, New Guinea, used for sugar production. It has stout, fibrous stalks that are rich in the sugar sucrose, which accumulates in the stalk internodes; the plant is two to six metres tall. All sugar cane species can interbreed and the major commercial cultivars are complex hybrids. Sugarcane belongs to the grass family Poaceae, an economically important seed plant family that includes maize, wheat and sorghum, many forage crops. Sucrose and purified in specialized mill factories, is used as raw material in the food industry or is fermented to produce ethanol. Sugarcane is the world's largest crop by production quantity, with 1.9 billion tonnes produced in 2016, Brazil accounting for 41% of the world total. In 2012, the Food and Agriculture Organization estimated it was cultivated on about 26 million hectares, in more than 90 countries.
The global demand for sugar is the primary driver of sugarcane agriculture. Cane accounts for 79% of sugar produced. Sugarcane predominantly grows in the subtropical regions. Other than sugar, products derived from sugarcane include falernum, rum, cachaça, ethanol. In some regions, people use sugarcane reeds to make pens, mats and thatch; the young, unexpanded inflorescence of Saccharum edule is eaten raw, steamed, or toasted, prepared in various ways in Southeast Asia, including Fiji and certain island communities of Indonesia. Sugarcane was an ancient crop of the Papuan people, it was introduced to Polynesia, Island Melanesia, Madagascar in prehistoric times via Austronesian sailors. It was introduced to southern China and India by Austronesian traders at around 1200 to 1000 BC; the Persians, followed by the Greeks, encountered the famous "reeds that produce honey without bees" in India between the 6th and 4th centuries BC. They adopted and spread sugarcane agriculture. Merchants began to trade in sugar from India, considered a luxury and an expensive spice.
In the 18th century AD, sugarcane plantations began in Caribbean, South American, Indian Ocean and Pacific island nations and the need for laborers became a major driver of large human migrations, both the voluntary in indentured servants. And the involuntary migrations, in the form of slave labor. Sugarcane is a tropical, perennial grass that forms lateral shoots at the base to produce multiple stems three to four m high and about 5 cm in diameter; the stems grow into cane stalk. A mature stalk is composed of 11–16% fiber, 12–16% soluble sugars, 2–3% nonsugars, 63–73% water. A sugarcane crop is sensitive to the climate, soil type, fertilizers, disease control and the harvest period; the average yield of cane stalk is 60–70 tonnes per hectare per year. However, this figure can vary between 30 and 180 tonnes per hectare depending on knowledge and crop management approach used in sugarcane cultivation. Sugarcane is a cash crop, but it is used as livestock fodder. There are two centers of domestication for sugarcane: one for Saccharum officinarum by Papuans in New Guinea and another for Saccharum sinense by Austronesians in Taiwan and southern China.
Papuans and Austronesians primarily used sugarcane as food for domesticated pigs. The spread of both S. officinarum and S. sinense is linked to the migrations of the Austronesian peoples. Saccharum barberi was only cultivated in India after the introduction of S. officinarum. Saccharum officinarum was first domesticated in New Guinea and the islands east of the Wallace Line by Papuans, where it is the modern center of diversity. Beginning at around 6,000 BP they were selectively bred from the native Saccharum robustum. From New Guinea it spread westwards to Island Southeast Asia after contact with Austronesians, where it hybridized with Saccharum spontaneum; the second domestication center is mainland southern China and Taiwan where S. sinense was a primary cultigen of the Austronesian peoples. Words for sugarcane exist in the Proto-Austronesian languages in Taiwan, reconstructed as *təbuS or **CebuS, which became *tebuh in Proto-Malayo-Polynesian, it was one of the original major crops of the Austronesian peoples from at least 5,500 BP.
Introduction of the sweeter S. officinarum may have replaced it throughout its cultivated range in Island Southeast Asia. From Island Southeast Asia, S. officinarum was spread eastward into Polynesia and Micronesia by Austronesian voyagers as a canoe plant by around 3,500 BP. It was spread westward and northward by around 3,000 BP to China and India by Austronesian traders, where it further hybridized with Saccharum sinense and Saccharum barberi. From there it spread further into the Mediterranean; the earliest known production of crystalline sugar began in northern India. The exact date of the first cane sugar production is unclear; the earliest evidence of sugar production comes from ancient Pali texts. Around the 8th century and Arab traders introduced sugar from medieval India to the other parts of the Abbasid Caliphate in the Mediterranean, Egypt, North Africa, Andalusia. By the 10th century, sources state, it was among the early crops brought to the Americas by the Spanish Andalu
World War I
World War I known as the First World War or the Great War, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. Contemporaneously described as "the war to end all wars", it led to the mobilisation of more than 70 million military personnel, including 60 million Europeans, making it one of the largest wars in history, it is one of the deadliest conflicts in history, with an estimated nine million combatants and seven million civilian deaths as a direct result of the war, while resulting genocides and the 1918 influenza pandemic caused another 50 to 100 million deaths worldwide. On 28 June 1914, Gavrilo Princip, a Bosnian Serb Yugoslav nationalist, assassinated the Austro-Hungarian heir Archduke Franz Ferdinand in Sarajevo, leading to the July Crisis. In response, on 23 July Austria-Hungary issued an ultimatum to Serbia. Serbia's reply failed to satisfy the Austrians, the two moved to a war footing. A network of interlocking alliances enlarged the crisis from a bilateral issue in the Balkans to one involving most of Europe.
By July 1914, the great powers of Europe were divided into two coalitions: the Triple Entente—consisting of France and Britain—and the Triple Alliance of Germany, Austria-Hungary and Italy. Russia felt it necessary to back Serbia and, after Austria-Hungary shelled the Serbian capital of Belgrade on the 28th, partial mobilisation was approved. General Russian mobilisation was announced on the evening of 30 July; when Russia failed to comply, Germany declared war on 1 August in support of Austria-Hungary, with Austria-Hungary following suit on 6th. German strategy for a war on two fronts against France and Russia was to concentrate the bulk of its army in the West to defeat France within four weeks shift forces to the East before Russia could mobilise. On 2 August, Germany demanded free passage through Belgium, an essential element in achieving a quick victory over France; when this was refused, German forces invaded Belgium on 3 August and declared war on France the same day. On 12 August and France declared war on Austria-Hungary.
In November 1914, the Ottoman Empire entered the war on the side of the Alliance, opening fronts in the Caucasus and the Sinai Peninsula. The war was fought in and drew upon each power's colonial empire as well, spreading the conflict to Africa and across the globe; the Entente and its allies would become known as the Allied Powers, while the grouping of Austria-Hungary and their allies would become known as the Central Powers. The German advance into France was halted at the Battle of the Marne and by the end of 1914, the Western Front settled into a battle of attrition, marked by a long series of trench lines that changed little until 1917. In 1915, Italy opened a front in the Alps. Bulgaria joined the Central Powers in 1915 and Greece joined the Allies in 1917, expanding the war in the Balkans; the United States remained neutral, although by doing nothing to prevent the Allies from procuring American supplies whilst the Allied blockade prevented the Germans from doing the same the U. S. became an important supplier of war material to the Allies.
After the sinking of American merchant ships by German submarines, the revelation that the Germans were trying to incite Mexico to make war on the United States, the U. S. declared war on Germany on 6 April 1917. Trained American forces would not begin arriving at the front in large numbers until mid-1918, but the American Expeditionary Force would reach some two million troops. Though Serbia was defeated in 1915, Romania joined the Allied Powers in 1916 only to be defeated in 1917, none of the great powers were knocked out of the war until 1918; the 1917 February Revolution in Russia replaced the Tsarist autocracy with the Provisional Government, but continuing discontent at the cost of the war led to the October Revolution, the creation of the Soviet Socialist Republic, the signing of the Treaty of Brest-Litovsk by the new government in March 1918, ending Russia's involvement in the war. This allowed the transfer of large numbers of German troops from the East to the Western Front, resulting in the German March 1918 Offensive.
This offensive was successful, but the Allies rallied and drove the Germans back in their Hundred Days Offensive. Bulgaria was the first Central Power to sign an armistice—the Armistice of Salonica on 29 September 1918. On 30 October, the Ottoman Empire capitulated. On 4 November, the Austro-Hungarian empire agreed to the Armistice of Villa Giusti after being decisively defeated by Italy in the Battle of Vittorio Veneto. With its allies defeated, revolution at home, the military no longer willing to fight, Kaiser Wilhelm abdicated on 9 November and Germany signed an armistice on 11 November 1918. World War I was a significant turning point in the political, cultural and social climate of the world; the war and its immediate aftermath sparked numerous uprisings. The Big Four (Britain, the United States, It
Natural rubber called India rubber or caoutchouc, as produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds, plus water. Thailand and Indonesia are two of the leading rubber producers. Forms of polyisoprene that are used as natural rubbers are classified as elastomers. Rubber is harvested in the form of the latex from the rubber tree or others; the latex is a sticky, milky colloid drawn off by making incisions in the bark and collecting the fluid in vessels in a process called "tapping". The latex is refined into rubber ready for commercial processing. In major areas, latex is allowed to coagulate in the collection cup; the coagulated lumps are processed into dry forms for marketing. Natural rubber is used extensively in many applications and products, either alone or in combination with other materials. In most of its useful forms, it has a large stretch ratio and high resilience, is waterproof; the major commercial source of natural rubber latex is the Pará rubber tree, a member of the spurge family, Euphorbiaceae.
This species is preferred. A properly managed tree responds to wounding by producing more latex for several years. Congo rubber a major source of rubber, came from vines in the genus Landolphia. Dandelion milk contains latex; the latex exhibits the same quality as the natural rubber from rubber trees. In the wild types of dandelion, latex content varies greatly. In Nazi Germany, research projects tried to use dandelions as a base for rubber production, but failed. In 2013, by inhibiting one key enzyme and using modern cultivation methods and optimization techniques, scientists in the Fraunhofer Institute for Molecular Biology and Applied Ecology in Germany developed a cultivar, suitable for commercial production of natural rubber. In collaboration with Continental Tires, IME began a pilot facility. Many other plants produce forms of latex rich in isoprene polymers, though not all produce usable forms of polymer as as the Pará; some of them require more elaborate processing to produce anything like usable rubber, most are more difficult to tap.
Some produce other desirable materials, for example chicle from Manilkara species. Others that have been commercially exploited, or at least showed promise as rubber sources, include the rubber fig, Panama rubber tree, various spurges, the related Scorzonera tau-saghyz, various Taraxacum species, including common dandelion and Russian dandelion, most for its hypoallergenic properties, guayule; the term gum rubber is sometimes applied to the tree-obtained version of natural rubber in order to distinguish it from the synthetic version. The first use of rubber was by the indigenous cultures of Mesoamerica; the earliest archeological evidence of the use of natural latex from the Hevea tree comes from the Olmec culture, in which rubber was first used for making balls for the Mesoamerican ballgame. Rubber was used by the Maya and Aztec cultures – in addition to making balls Aztecs used rubber for other purposes such as making containers and to make textiles waterproof by impregnating them with the latex sap.
The Pará rubber tree is indigenous to South America. Charles Marie de La Condamine is credited with introducing samples of rubber to the Académie Royale des Sciences of France in 1736. In 1751, he presented a paper by François Fresneau to the Académie that described many of rubber's properties; this has been referred to as the first scientific paper on rubber. In England, Joseph Priestley, in 1770, observed that a piece of the material was good for rubbing off pencil marks on paper, hence the name "rubber", it made its way around England. In 1764 François Fresnau discovered. Giovanni Fabbroni is credited with the discovery of naphtha as a rubber solvent in 1779. South America remained the main source of latex rubber used during much of the 19th century; the rubber trade was controlled by business interests but no laws expressly prohibited the export of seeds or plants. In 1876, Henry Wickham smuggled 70,000 Pará rubber tree seeds from Brazil and delivered them to Kew Gardens, England. Only 2,400 of these germinated.
Seedlings were sent to India, British Ceylon, Dutch East Indies and British Malaya. Malaya was to become the biggest producer of rubber. In the early 1900s, the Congo Free State in Africa was a significant source of natural rubber latex gathered by forced labor. King Leopold II's colonial state brutally enforced production quotas. Tactics to enforce the rubber quotas included removing the hands of victims to prove they had been killed. Soldiers came back from raids with baskets full of chopped-off hands. Villages that resisted were razed to encourage better compliance locally. See Atrocities in the Congo Free State for more information on the rubber trade in the Congo Free State in the late 1800s and early 1900s. Liberia and Nigeria started production. In India, commercial cultivation was introduced by British planters, although the experimental efforts to grow rubber on a commercial scale were initiated as early as 1873 at the Calcutta Botanical Gardens; the first commercial Hevea plantations were established at Thattekadu in Kerala in 1902.
In years the plantation expanded to Karnataka, Tamil Nadu and the Andaman and Nicobar Islands of India. India today is the