1.
Recorder (musical instrument)
–
The recorder is a woodwind musical instrument in the group known as internal duct flutes—flutes with a whistle mouthpiece. It is distinguished from other duct flutes by having a thumb-hole for the hand and seven finger-holes. It is the most prominent duct flute in the classical tradition. Recorders are made in different sizes with compasses corresponding to different vocal ranges, the sizes most commonly in use today are the soprano, alto, tenor and bass. Recorders are traditionally constructed from wood and ivory, although the use of plastics is now common, other characteristics of their construction, such as bore profile and fingering systems, have varied over time and between instruments. The recorder is first documented in the Middle Ages, and continued to enjoy popularity in the renaissance and baroque periods. It was revived in the 20th century as part of the historically informed performance movement, today, there are many professional recorder players who demonstrate the instruments full solo range and a large community of amateurs. The sound of the recorder is described as clear and sweet. It is notable for its response and its corresponding ability to produce a wide variety of articulations. This ability, coupled with its open finger holes, allow it to produce a variety of tone colors. Acoustically, its tone is relatively pure and odd harmonics predominate in its sound, the instrument has been known by its modern English name at least since the 14th century. David Lasocki reports the earliest use of recorder in the accounts of the Earl of Derby in 1388. By the 15th century, the name had appeared in English literature, the instrument name recorder derives from the Latin recordārī, by way of Middle French recorder and MFr recordeur, itself derived from MFr recorder. Thus, the recorder cannot have been named after the sound of birds, the name of the instrument is also uniquely English, in Middle French there is no equivalent noun sense of recorder referring to a musical instrument. Partridge indicates that the use of the instrument by jongleurs led to its association with the verb, recorder the minstrels action, the reason we know this instrument as the recorder and not one of the other instruments played by the jongleurs is uncertain. Until about 1695, the recorder and flute overlapped, but from 1673 to the late 1720s in England. Until at least 1765, some still used flute to mean recorder. Until the mid 18th century, musical scores written in Italian refer to the instrument as flauto and this distinction, like the English switch from recorder to flute, has caused confusion among modern editors, writers and performers
2.
Piston
–
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder, in some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder wall. An internal combustion engine is acted upon by the pressure of the combustion gases in the combustion chamber space at the top of the cylinder. This force then acts downwards through the rod and onto the crankshaft. The connecting rod is attached to the piston by a swivelling gudgeon pin and this pin is mounted within the piston, unlike the steam engine, there is no piston rod or crosshead. The pin itself is of hardened steel and is fixed in the piston, a few designs use a fully floating design that is loose in both components. All pins must be prevented from moving sideways and the ends of the pin digging into the cylinder wall, gas sealing is achieved by the use of piston rings. These are a number of iron rings, fitted loosely into grooves in the piston. The rings are split at a point in the rim, allowing them to press against the cylinder with a light spring pressure. Two types of ring are used, the rings have solid faces and provide gas sealing, lower rings have narrow edges. There are many proprietary and detail design features associated with piston rings, pistons are cast from aluminium alloys. For better strength and fatigue life, some racing pistons may be forged instead, early pistons were of cast iron, but there were obvious benefits for engine balancing if a lighter alloy could be used. To produce pistons that could survive engine combustion temperatures, it was necessary to develop new alloys such as Y alloy and Hiduminium, a few early gas engines had double-acting cylinders, but otherwise effectively all internal combustion engine pistons are single-acting. During World War II, the US submarine Pompano was fitted with a prototype of the infamously unreliable H. O. R, although compact, for use in a cramped submarine, this design of engine was not repeated. Media related to Internal combustion engine pistons at Wikimedia Commons Trunk pistons are long relative to their diameter and they act both as a piston and cylindrical crosshead. As the connecting rod is angled for much of its rotation, a longer piston helps to support this
3.
Bicycle pump
–
A bicycle pump is a type of positive-displacement air pump specifically designed for inflating bicycle tires. It has a connection or adapter for use with one or both of the two most common types of valves used on bicycles, Schrader or Presta, a third type of valve called the Dunlop valve exists, but tubes with these valves can be filled using a Presta pump. Several basic types are available, Floor pumps Frame mounted Compact or mini Foot operated Double action In its most basic form, during the up-stroke, this piston draws air through a one-way valve into the pump from the outside. During the down-stroke, the piston displaces the air from the pump into the bicycle tire. Most floor pumps, also commonly called track pumps, have a built in pressure gauge to indicate tire pressure, electrically-operated pumps intended to inflate car tires can in principle be used to inflate a bicycle tire if the right type of connection is available. Some such pumps are designed to cut off before a suitable pressure, others may not cut off, but deliver a high rate of flow to fill the larger car tire, with a risk of overinflating and bursting a bicycle tire unless it is stopped with split-second timing. The first bicycle pump consisted of a cylinder that had a metal rod running down the middle of it. This would have forced the air out of the cylinder and then sucked in new air when the rod was pulled up again. Many modern pumps use a similar method, while some, such as the electric pumps. When the cylinder is compressed, air is pushed down the tube of the pump and then into the tire via the valve, which is forced open by the pressure of the air. When the handle is pulled up again, the valve shuts off automatically so that the air cannot escape from the tire, some pumps have a gauge that shows the pressure of air that is forced into the tire. Once the tire is at the pressure, the pump valve can be removed from the tire. There are two types of tire valves to which the bicycle tire pump attaches. These are the Presta valve and the Schrader valve, some pumps fit both types of valves, whereas others do not, but adapters are available that enable the pump to fit any type of valve. The AVACS feature is available on pump models and can also be bought as a separate valve attachment. There are three types of bicycle pumps Stand pump Hand pump Foot pump Also known as a floor or track pump. To operate, the user rests the base of the pump on the floor, resting feet at the base, an additional tube must connect the pump to the fill valve, which may create dead volume. There are two types, tubed and integral
4.
Africa
–
Africa is the worlds second-largest and second-most-populous continent. At about 30.3 million km² including adjacent islands, it covers 6% of Earths total surface area and 20.4 % of its land area. With 1.2 billion people as of 2016, it accounts for about 16% of the human population. The continent includes Madagascar and various archipelagos and it contains 54 fully recognized sovereign states, nine territories and two de facto independent states with limited or no recognition. Africas population is the youngest amongst all the continents, the age in 2012 was 19.7. Algeria is Africas largest country by area, and Nigeria by population, afarensis, Homo erectus, H. habilis and H. ergaster – with the earliest Homo sapiens found in Ethiopia being dated to circa 200,000 years ago. Africa straddles the equator and encompasses numerous climate areas, it is the continent to stretch from the northern temperate to southern temperate zones. Africa hosts a diversity of ethnicities, cultures and languages. In the late 19th century European countries colonized most of Africa, Africa also varies greatly with regard to environments, economics, historical ties and government systems. However, most present states in Africa originate from a process of decolonization in the 20th century, afri was a Latin name used to refer to the inhabitants of Africa, which in its widest sense referred to all lands south of the Mediterranean. This name seems to have referred to a native Libyan tribe. The name is connected with Hebrew or Phoenician ʿafar dust. The same word may be found in the name of the Banu Ifran from Algeria and Tripolitania, under Roman rule, Carthage became the capital of the province of Africa Proconsularis, which also included the coastal part of modern Libya. The Latin suffix -ica can sometimes be used to denote a land, the later Muslim kingdom of Ifriqiya, modern-day Tunisia, also preserved a form of the name. According to the Romans, Africa lay to the west of Egypt, while Asia was used to refer to Anatolia, as Europeans came to understand the real extent of the continent, the idea of Africa expanded with their knowledge. 25,4, whose descendants, he claimed, had invaded Libya, isidore of Seville in Etymologiae XIV.5.2. Suggests Africa comes from the Latin aprica, meaning sunny, massey, in 1881, stated that Africa is derived from the Egyptian af-rui-ka, meaning to turn toward the opening of the Ka. The Ka is the double of every person and the opening of the Ka refers to a womb or birthplace
5.
Asia
–
Asia covers an area of 44,579,000 square kilometres, about 30% of Earths total land area and 8. 7% of the Earths total surface area. The continent, which has long been home to the majority of the population, was the site of many of the first civilizations. Asia is notable for not only its large size and population. In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, the western boundary with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. The most commonly accepted boundaries place Asia to the east of the Suez Canal, the Ural River, and the Ural Mountains, and south of the Caucasus Mountains, China and India alternated in being the largest economies in the world from 1 to 1800 A. D. The accidental discovery of America by Columbus in search for India demonstrates this deep fascination, the Silk Road became the main East-West trading route in the Asian hitherland while the Straits of Malacca stood as a major sea route. Asia has exhibited economic dynamism as well as robust population growth during the 20th century, given its size and diversity, the concept of Asia—a name dating back to classical antiquity—may actually have more to do with human geography than physical geography. Asia varies greatly across and within its regions with regard to ethnic groups, cultures, environments, economics, historical ties, the boundary between Asia and Africa is the Red Sea, the Gulf of Suez, and the Suez Canal. This makes Egypt a transcontinental country, with the Sinai peninsula in Asia, the border between Asia and Europe was historically defined by European academics. In Sweden, five years after Peters death, in 1730 Philip Johan von Strahlenberg published a new atlas proposing the Urals as the border of Asia, the Russians were enthusiastic about the concept, which allowed them to keep their European identity in geography. Tatishchev announced that he had proposed the idea to von Strahlenberg, the latter had suggested the Emba River as the lower boundary. Over the next century various proposals were made until the Ural River prevailed in the mid-19th century, the border had been moved perforce from the Black Sea to the Caspian Sea into which the Ural River projects. The border between the Black Sea and the Caspian is usually placed along the crest of the Caucasus Mountains, the border between Asia and the loosely defined region of Oceania is usually placed somewhere in the Malay Archipelago. The terms Southeast Asia and Oceania, devised in the 19th century, have had several different geographic meanings since their inception. The chief factor in determining which islands of the Malay Archipelago are Asian has been the location of the possessions of the various empires there. Lewis and Wigen assert, The narrowing of Southeast Asia to its present boundaries was thus a gradual process, Asia is larger and more culturally diverse than Europe. It does not exactly correspond to the borders of its various types of constituents. From the time of Herodotus a minority of geographers have rejected the three-continent system on the grounds there is no or is no substantial physical separation between them
6.
Pacific Ocean
–
The Pacific Ocean is the largest and deepest of the Earths oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean in the south and is bounded by Asia and Australia in the west, the Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 metres. Both the center of the Water Hemisphere and the Western Hemisphere are in the Pacific Ocean, the oceans current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish circumnavigation of the world in 1521, as he encountered favourable winds on reaching the ocean. He called it Mar Pacífico, which in both Portuguese and Spanish means peaceful sea, important human migrations occurred in the Pacific in prehistoric times. Long-distance trade developed all along the coast from Mozambique to Japan, trade, and therefore knowledge, extended to the Indonesian islands but apparently not Australia. By at least 878 when there was a significant Islamic settlement in Canton much of trade was controlled by Arabs or Muslims. In 219 BC Xu Fu sailed out into the Pacific searching for the elixir of immortality, from 1404 to 1433 Zheng He led expeditions into the Indian Ocean. The east side of the ocean was discovered by Spanish explorer Vasco Núñez de Balboa in 1513 after his expedition crossed the Isthmus of Panama and he named it Mar del Sur because the ocean was to the south of the coast of the isthmus where he first observed the Pacific. Later, Portuguese explorer Ferdinand Magellan sailed the Pacific East to West on a Castilian expedition of world circumnavigation starting in 1519, Magellan called the ocean Pacífico because, after sailing through the stormy seas off Cape Horn, the expedition found calm waters. The ocean was often called the Sea of Magellan in his honor until the eighteenth century, sailing around and east of the Moluccas, between 1525 and 1527, Portuguese expeditions discovered the Caroline Islands, the Aru Islands, and Papua New Guinea. In 1542–43 the Portuguese also reached Japan, in 1564, five Spanish ships consisting of 379 explorers crossed the ocean from Mexico led by Miguel López de Legazpi and sailed to the Philippines and Mariana Islands. The Manila galleons operated for two and a half centuries linking Manila and Acapulco, in one of the longest trade routes in history, Spanish expeditions also discovered Tuvalu, the Marquesas, the Cook Islands, the Solomon Islands, and the Admiralty Islands in the South Pacific. In the 16th and 17th century Spain considered the Pacific Ocean a Mare clausum—a sea closed to other naval powers, as the only known entrance from the Atlantic the Strait of Magellan was at times patrolled by fleets sent to prevent entrance of non-Spanish ships. On the western end of the Pacific Ocean the Dutch threatened the Spanish Philippines, Spain also sent expeditions to the Pacific Northwest reaching Vancouver Island in southern Canada, and Alaska. The French explored and settled Polynesia, and the British made three voyages with James Cook to the South Pacific and Australia, Hawaii, and the North American Pacific Northwest, one of the earliest voyages of scientific exploration was organized by Spain in the Malaspina Expedition of 1789–1794. It sailed vast areas of the Pacific, from Cape Horn to Alaska, Guam and the Philippines, New Zealand, Australia, and the South Pacific. Growing imperialism during the 19th century resulted in the occupation of much of Oceania by other European powers, and later, Japan, in Oceania, France got a leading position as imperial power after making Tahiti and New Caledonia protectorates in 1842 and 1853 respectively. After navy visits to Easter Island in 1875 and 1887, Chilean navy officer Policarpo Toro managed to negotiate an incorporation of the island into Chile with native Rapanui in 1888, by occupying Easter Island, Chile joined the imperial nations
_-_The_Noun_Project.svg){kind=small}