A shuttle is a tool designed to neatly and compactly store a holder that carries the thread of the weft yarn while weaving with a loom. Shuttles are thrown or passed back and forth through the shed, between the yarn threads of the warp in order to weave in the weft; the simplest shuttles, known as "stick shuttles", are made from a flat, narrow piece of wood with notches on the ends to hold the weft yarn. More complicated shuttles incorporate pirns. In the United States, shuttles are made of wood from the flowering dogwood, because it is hard, resists splintering, can be polished to a smooth finish. Shuttles were passed back and forth by hand. However, John Kay invented a loom in 1733; this shuttle could be thrown through the warp, which allowed much wider cloth to be woven much more and made the development of machine looms much simpler. Though air-jet and water-jet looms are common in large operations, many companies still use flying shuttle looms; this is due in large part to their being easier to maintain.
In modern flying shuttle looms, the shuttle itself is made of rounded steel, with a hook in the back which carries the filler, or "pick." The act of "kissing the shuttle", in which weavers used their mouths to pull thread through the eye of a shuttle when the pirn was replaced, contributed to the spread of disease. Chandler, Deborah. Learning to Weave, Colorado: Interweave Press LLC. ISBN 1-883010-03-9 Pak Shuttle Company Ltd. Shuttle looms for narrow fabrics
The inch is a unit of length in the imperial and United States customary systems of measurement. It is equal to 1⁄12 of a foot. Derived from the Roman uncia, the word inch is sometimes used to translate similar units in other measurement systems understood as deriving from the width of the human thumb. Standards for the exact length of an inch have varied in the past, but since the adoption of the international yard during the 1950s and 1960s it has been based on the metric system and defined as 25.4 mm. The English word "inch" was an early borrowing from Latin uncia not present in other Germanic languages; the vowel change from Latin /u/ to Old English /y/ is known as umlaut. The consonant change from the Latin /k/ to English /tʃ/ is palatalisation. Both were features of Old English phonology. "Inch" is cognate with "ounce", whose separate pronunciation and spelling reflect its reborrowing in Middle English from Anglo-Norman unce and ounce. In many other European languages, the word for "inch" is the same as or derived from the word for "thumb", as a man's thumb is about an inch wide.
Examples include Afrikaans: duim. The inch is a used customary unit of length in the United States and the United Kingdom, it is used in Japan for electronic parts display screens. In most of continental Europe, the inch is used informally as a measure for display screens. For the United Kingdom, guidance on public sector use states that, since 1 October 1995, without time limit, the inch is to be used as a primary unit for road signs and related measurements of distance and may continue to be used as a secondary or supplementary indication following a metric measurement for other purposes; the international standard symbol for inch is in but traditionally the inch is denoted by a double prime, approximated by double quotes, the foot by a prime, approximated by an apostrophe. For example, three feet two inches can be written as 3′ 2″. Subdivisions of an inch are written using dyadic fractions with odd number numerators. 1 international inch is equal to: 10,000 tenths 1,000 thou or mil 100 points or gries 72 PostScript points 10, 12, 16, or 40 lines 6 computer picas 3 barleycorns 25.4 millimetres 0.999998 US Survey inches 1/3 or 0.333 palms 1/4 or 0.25 hands 1/12 or 0.08333 feet 1/36 or 0.02777 yards The earliest known reference to the inch in England is from the Laws of Æthelberht dating to the early 7th century, surviving in a single manuscript, the Textus Roffensis from 1120.
Paragraph LXVII sets out the fine for wounds of various depths: one inch, one shilling, two inches, two shillings, etc. An Anglo-Saxon unit of length was the barleycorn. After 1066, 1 inch was equal to 3 barleycorns, which continued to be its legal definition for several centuries, with the barleycorn being the base unit. One of the earliest such definitions is that of 1324, where the legal definition of the inch was set out in a statute of Edward II of England, defining it as "three grains of barley and round, placed end to end, lengthwise". Similar definitions are recorded in both Welsh medieval law tracts. One, dating from the first half of the 10th century, is contained in the Laws of Hywel Dda which superseded those of Dyfnwal, an earlier definition of the inch in Wales. Both definitions, as recorded in Ancient Laws and Institutes of Wales, are that "three lengths of a barleycorn is the inch". King David I of Scotland in his Assize of Weights and Measures is said to have defined the Scottish inch as the width of an average man's thumb at the base of the nail including the requirement to calculate the average of a small, a medium, a large man's measures.
However, the oldest surviving manuscripts date from the early 14th century and appear to have been altered with the inclusion of newer material. In 1814, Charles Butler, a mathematics teacher at Cheam School, recorded the old legal definition of the inch to be "three grains of sound ripe barley being taken out the middle of the ear, well dried, laid end to end in a row", placed the barleycorn, not the inch, as the base unit of the English Long Measure system, from which all other units were derived. John Bouvier recorded in his 1843 law dictionary that the barleycorn was the fundamental measure. Butler observed, that "s the length of the barley-corn cannot be fixed, so the inch according to this method will be uncertain", noting that a standard inch measure was now kept in the Exchequer chamber and, the legal definition of the inch; this was a point made by George Long in his 1842 Penny Cyclopædia, observing that st
A loom is a device used to weave cloth and tapestry. The basic purpose of any loom is to hold the warp threads under tension to facilitate the interweaving of the weft threads; the precise shape of the loom and its mechanics may vary. The word "loom" is derived from the Old English geloma, formed from ge- and loma, a root of unknown origin. In 1404 it was used to mean a machine to enable weaving thread into cloth. By 1838, it had gained the meaning of a machine for interlacing thread. Weaving is done by intersecting the longitudinal threads, the warp, i.e. "that, thrown across", with the transverse threads, the weft, i.e. "that, woven". The major components of the loom are the warp beam, harnesses or shafts, shuttle and takeup roll. In the loom, yarn processing includes shedding, picking and taking-up operations; these are the principal motions. Shedding. Shedding is the raising of part of the warp yarn to form a shed, through which the filling yarn, carried by the shuttle, can be inserted, forming the weft.
On the modern loom and intricate shedding operations are performed automatically by the heddle or heald frame known as a harness. This is a rectangular frame to which a series of wires, called healds, are attached; the yarns are passed through the eye holes of the heddles. The weave pattern determines which harness controls which warp yarns, the number of harnesses used depends on the complexity of the weave. Two common methods of controlling the heddles are a Jacquard Head. Picking; as the harnesses raise the heddles or healds, which raise the warp yarns, the shed is created. The filling yarn is inserted through the shed by a small carrier device called a shuttle; the shuttle is pointed at each end to allow passage through the shed. In a traditional shuttle loom, the filling yarn is wound onto a quill, which in turn is mounted in the shuttle; the filling yarn emerges through a hole in the shuttle. A single crossing of the shuttle from one side of the loom to the other is known as a pick; as the shuttle moves back and forth across the shed, it weaves an edge, or selvage, on each side of the fabric to prevent the fabric from raveling.
Battening. Between the heddles and the takeup roll, the warp threads pass through another frame called the reed; the portion of the fabric, formed but not yet rolled up on the takeup roll is called the fell. After the shuttle moves across the loom laying down the fill yarn, the weaver uses the reed to press each filling yarn against the fell. Conventional shuttle looms can operate at speeds of about 150 to 160 picks per minute. There are two secondary motions, because with each weaving operation the newly constructed fabric must be wound on a cloth beam; this process is called taking up. At the same time, the warp yarns must be released from the warp beams. To become automatic, a loom needs a tertiary motion, the filling stop motion; this will brake the loom. An automatic loom requires 0.125 hp to 0.5 hp to operate. The back strap loom is a simple loom, it consists of two bars between which the warps are stretched. One bar is attached to a fixed object and the other to the weaver by means of a strap around the back.
The weaver uses their body weight to tension the loom. On traditional looms, the two main sheds are operated by means of a shed roll over which one set of warps pass, continuous string heddles which encase each of the warps in the other set. To open the shed controlled by the string heddles, the weaver relaxes tension on the warps and raises the heddles; the other shed is opened by drawing the shed roll toward the weaver. Both simple and complex textiles can be woven on this loom. Width is limited to. Warp faced textiles decorated with intricate pick-up patterns woven in complementary and supplementary warp techniques are woven by indigenous peoples today around the world, they produce such things as belts, bags and carrying cloths. Supplementary weft patterning and brocading is practiced in many regions. Balanced weaves are possible on the backstrap loom. Today, commercially produced backstrap loom kits include a rigid heddle; the warp-weighted loom is a vertical loom. The earliest evidence of warp-weighted looms comes from sites belonging to the Starčevo culture in modern Serbia and Hungary and from late Neolithic sites in Switzerland.
This loom was used in Ancient Greece, spread north and west throughout Europe thereafter. Its defining characteristic is hanging weights. Extra warp thread is wound around the weights; when a weaver has reached the bottom of the available warp, the completed section can be rolled around the top beam, additional lengths of warp threads can be unwound from the weights to continue. This frees the weaver from vertical size constraint. A drawloom is a hand-loom for weaving figured cloth. In a drawloom, a "figure harness" is used to control each warp thread separately. A drawloom requires two operators, the weaver and an assistant called a "drawboy" to manage the figure harness; the earliest confirmed drawloom fabrics come from the State of Chu and date c. 400 BC. Most scholars attribute the invention of the dra
The chicken is a type of domesticated fowl, a subspecies of the red junglefowl. It is one of the most common and widespread domestic animals, with a total population of more than 19 billion as of 2011. There are more chickens in the world than domesticated fowl. Humans keep chickens as a source of food and, less as pets. Raised for cockfighting or for special ceremonies, chickens were not kept for food until the Hellenistic period. Genetic studies have pointed to multiple maternal origins in South Asia, Southeast Asia, East Asia, but with the clade found in the Americas, the Middle East and Africa originating in the Indian subcontinent. From ancient India, the domesticated chicken spread to Lydia in western Asia Minor, to Greece by the 5th century BC. Fowl had been known in Egypt since the mid-15th century BC, with the "bird that gives birth every day" having come to Egypt from the land between Syria and Shinar, according to the annals of Thutmose III; the chicken used for regular egg and meat production worldwide are corn-ply Broilers with white feathers, yellowish skin and faster growth rate invented in United States of America In the UK and Ireland, adult male chickens over the age of one year are known as cocks, whereas in the United States, Canada and New Zealand, they are more called roosters.
Males less than a year old are cockerels. Castrated roosters are called capons. Females over a year old are known as hens, younger females as pullets, although in the egg-laying industry, a pullet becomes a hen when she begins to lay eggs, at 16 to 20 weeks of age. In Australia and New Zealand, there is a generic term chook to describe all both sexes; the young are called chicks. "Chicken" referred to young domestic fowl. The species as a whole was called domestic fowl, or just fowl; this use of "chicken" survives in the phrase "Hen and Chickens", sometimes used as a British public house or theatre name, to name groups of one large and many small rocks or islands in the sea. The word "chicken" is sometimes erroneously construed to mean females despite the term "hen" for females being in wide circulation, the term “rooster” for males being that most used. In the Deep South of the United States, chickens are referred to by the slang term yardbird. Chickens are omnivores. In the wild, they scratch at the soil to search for seeds and animals as large as lizards, small snakes, or young mice.
The average chicken may live depending on the breed. The world's oldest known chicken was a hen which died of heart failure at the age of 16 years according to the Guinness World Records. Roosters can be differentiated from hens by their striking plumage of long flowing tails and shiny, pointed feathers on their necks and backs, which are of brighter, bolder colours than those of females of the same breed. However, in some breeds, such as the Sebright chicken, the rooster has only pointed neck feathers, the same colour as the hen's; the identification can be made by looking at the comb, or from the development of spurs on the male's legs. Adult chickens have a fleshy crest on their heads called a comb, or cockscomb, hanging flaps of skin either side under their beaks called wattles. Collectively and other fleshy protuberances on the head and throat are called caruncles. Both the adult male and female have wattles and combs, but in most breeds these are more prominent in males. A muff or beard is a mutation found in several chicken breeds which causes extra feathering under the chicken's face, giving the appearance of a beard.
Domestic chickens are not capable of long distance flight, although lighter birds are capable of flying for short distances, such as over fences or into trees. Chickens may fly to explore their surroundings, but do so only to flee perceived danger. Chickens live together in flocks, they have a communal approach to the incubation of eggs and raising of young. Individual chickens in a flock will dominate others, establishing a "pecking order", with dominant individuals having priority for food access and nesting locations. Removing hens or roosters from a flock causes a temporary disruption to this social order until a new pecking order is established. Adding hens younger birds, to an existing flock can lead to fighting and injury; when a rooster finds food, he may call other chickens to eat first. He does this by clucking in a high pitch as well as dropping the food; this behaviour may be observed in mother hens to call their chicks and encourage them to eat. A rooster's crowing is a loud and sometimes shrill call and sends a territorial signal to other roosters.
However, roosters may crow in response to sudden disturbances within their surroundings. Hens cluck loudly after laying an egg, to call their chicks. Chickens give different warning calls when they sense a predator approaching from the air or on the ground. To initiate courting, some roosters may dance in a circle around or near a hen lowering the wing, closest to the hen; the dance triggers a response in the hen and when she responds to his "call", the rooster may mount the hen and proceed with the mating. More matin
The millimetre or millimeter is a unit of length in the metric system, equal to one thousandth of a metre, the SI base unit of length. Therefore, there are one thousand millimetres in a metre. There are ten millimetres in a centimetre. One millimetre is equal to 1000000 nanometres. A millimetre is equal to 5⁄127 of an inch. Since 1983, the metre has been defined as "the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second". A millimetre, 1/1000 of a metre, is therefore the distance travelled by light in 1/299792458000 of a second. A common shortening of millimetre in spoken English is "mil"; this can cause confusion since in the United States, "mil" traditionally means a thousandth of an inch. For the purposes of compatibility with Chinese and Korean characters, Unicode has symbols for: millimetre - code U+339C square millimetre - code U+339F cubic millimetre - code U+33A3In Japanese typography, these square symbols were used for laying out unit symbols without distorting the grid layout of text characters.
On a metric ruler, the smallest measurements are millimetres. High-quality engineering rules may be graduated in increments of 0.5 mm. Digital callipers are capable of reading increments as small as 0.01 mm. Microwaves with a frequency of 300 GHz have a wavelength of 1 mm. Using wavelengths between 30 GHz and 300 GHz for data transmission, in contrast to the 300 MHz to 3 GHz used in mobile devices, has the potential to allow data transfer rates of 10 gigabits per second; the smallest distances the human eye can resolve is around 0.02 to 0.04 mm the width of a human hair. A sheet of paper is between 0.07 mm and 0.18 mm thick, with ordinary printer paper or copy paper a tenth of a millimetre thick. Metric system Orders of magnitude Submillimeter
Battledore and shuttlecock
Battledore and shuttlecock, or jeu de volant, is an early game related to that of modern badminton. This game is played by two people, using small rackets, called battledores, made of parchment or rows of gut stretched across wooden frames, shuttlecocks, made of a base of some light material, such as cork, with trimmed feathers fixed around the top; the object is for players to bat the shuttlecock from one to the other as many times as possible without allowing it to fall to the ground. Games with a shuttlecock are believed to have originated about 2,000 years ago, it has been popular in India, China and Siam for at least that long. In Europe, it was played by children for centuries, its modern development is the game of badminton. Hanetsuki
Aerodynamics, from Greek ἀήρ aer + δυναμική, is the study of motion of air as interaction with a solid object, such as an airplane wing. It is a sub-field of fluid dynamics and gas dynamics, many aspects of aerodynamics theory are common to these fields; the term aerodynamics is used synonymously with gas dynamics, the difference being that "gas dynamics" applies to the study of the motion of all gases, is not limited to air. The formal study of aerodynamics began in the modern sense in the eighteenth century, although observations of fundamental concepts such as aerodynamic drag were recorded much earlier. Most of the early efforts in aerodynamics were directed toward achieving heavier-than-air flight, first demonstrated by Otto Lilienthal in 1891. Since the use of aerodynamics through mathematical analysis, empirical approximations, wind tunnel experimentation, computer simulations has formed a rational basis for the development of heavier-than-air flight and a number of other technologies.
Recent work in aerodynamics has focused on issues related to compressible flow and boundary layers and has become computational in nature. Modern aerodynamics only dates back to the seventeenth century, but aerodynamic forces have been harnessed by humans for thousands of years in sailboats and windmills, images and stories of flight appear throughout recorded history, such as the Ancient Greek legend of Icarus and Daedalus. Fundamental concepts of continuum and pressure gradients appear in the work of Aristotle and Archimedes. In 1726, Sir Isaac Newton became the first person to develop a theory of air resistance, making him one of the first aerodynamicists. Dutch-Swiss mathematician Daniel Bernoulli followed in 1738 with Hydrodynamica in which he described a fundamental relationship between pressure and flow velocity for incompressible flow known today as Bernoulli's principle, which provides one method for calculating aerodynamic lift. In 1757, Leonhard Euler published the more general Euler equations which could be applied to both compressible and incompressible flows.
The Euler equations were extended to incorporate the effects of viscosity in the first half of the 1800s, resulting in the Navier–Stokes equations. The Navier-Stokes equations are the most general governing equations of fluid flow and but are difficult to solve for the flow around all but the simplest of shapes. In 1799, Sir George Cayley became the first person to identify the four aerodynamic forces of flight, as well as the relationships between them, in doing so outlined the path toward achieving heavier-than-air flight for the next century. In 1871, Francis Herbert Wenham constructed the first wind tunnel, allowing precise measurements of aerodynamic forces. Drag theories were developed by Jean le Rond d'Alembert, Gustav Kirchhoff, Lord Rayleigh. In 1889, Charles Renard, a French aeronautical engineer, became the first person to reasonably predict the power needed for sustained flight. Otto Lilienthal, the first person to become successful with glider flights, was the first to propose thin, curved airfoils that would produce high lift and low drag.
Building on these developments as well as research carried out in their own wind tunnel, the Wright brothers flew the first powered airplane on December 17, 1903. During the time of the first flights, Frederick W. Lanchester, Martin Kutta, Nikolai Zhukovsky independently created theories that connected circulation of a fluid flow to lift. Kutta and Zhukovsky went on to develop a two-dimensional wing theory. Expanding upon the work of Lanchester, Ludwig Prandtl is credited with developing the mathematics behind thin-airfoil and lifting-line theories as well as work with boundary layers; as aircraft speed increased, designers began to encounter challenges associated with air compressibility at speeds near or greater than the speed of sound. The differences in air flows under such conditions leads to problems in aircraft control, increased drag due to shock waves, the threat of structural failure due to aeroelastic flutter; the ratio of the flow speed to the speed of sound was named the Mach number after Ernst Mach, one of the first to investigate the properties of supersonic flow.
William John Macquorn Rankine and Pierre Henri Hugoniot independently developed the theory for flow properties before and after a shock wave, while Jakob Ackeret led the initial work of calculating the lift and drag of supersonic airfoils. Theodore von Kármán and Hugh Latimer Dryden introduced the term transonic to describe flow speeds around Mach 1 where drag increases rapidly; this rapid increase in drag led aerodynamicists and aviators to disagree on whether supersonic flight was achievable until the sound barrier was broken for the first time in 1947 using the Bell X-1 aircraft. By the time the sound barrier was broken, aerodynamicists' understanding of the subsonic and low supersonic flow had matured; the Cold War prompted the design of an ever-evolving line of high performance aircraft. Computational fluid dynamics began as an effort to solve for flow properties around complex objects and has grown to the point where entire aircraft can be designed using computer software, with wind-tunnel tests followed by flight tests to confirm the computer predictions.
Understanding of supersonic and hypersonic aerodynamics has matured since the 1960s, the goals of aerodynamicists have shifted from the behavior of fluid flow to the engineering of a vehicle such that it interacts pedictably with the fluid flow. Designing aircraft for supersonic and hypersonic conditions, as well as the desire to improve the aerodynamic efficiency of current aircraft and propulsion systems, continues to motivate new research in aero