119-526: The sanshin ( 三線 , lit., "three strings") is an Okinawan and Amami Islands musical instrument and precursor of the mainland Japanese shamisen ( 三味線 ). Often likened to a banjo , it consists of a snakeskin -covered body, neck and three strings. Its close resemblance in both appearance and name to the Chinese sanxian suggests Chinese origins, the then- Ryūkyū Kingdom (pre-Japanese Okinawa) having very close ties with Imperial China. In
238-542: A plectrum ( bachi ), made of a material such as the water buffalo horn , on the index finger . Today, some use a guitar pick or the nail of the index finger. In Amami, long, narrow bamboo plectra are also used, which allow a higher-pitched tone than that of the Okinawa sanshin. A bamboo bridge raises the strings off the skin, which are white, except in Amami , where they are yellower and thinner. The traditional names for
357-565: A ring-opening polymerization . The peptide bond within the caprolactam is broken with the exposed active groups on each side being incorporated into two new bonds as the monomer becomes part of the polymer backbone. The 428 °F (220 °C) melting point of nylon 6 is lower than the 509 °F (265 °C) melting point of nylon 66 . Homopolymer nylons are derived from one monomer. Examples of these polymers that are or were commercially available: Nylons can also be synthesized from dinitriles using acid catalysis. For example, this method
476-457: A different molecule based on caprolactam , on January 29, 1938. In the spring of 1930, Carothers and his team had already synthesized two new polymers. One was neoprene , a synthetic rubber greatly used during World War II. The other was a white elastic but strong paste that would later become nylon. After these discoveries, Carothers' team was made to shift its research from a more pure research approach investigating general polymerization to
595-554: A major figure in the Beheiren movement (Foundation of Citizens for Peace in Vietnam), believed that the return of Okinawa to Japan would lead to the removal of U.S. forces, ending Japan's involvement in Vietnam. In a speech delivered in 1967, Oda was critical of Prime Minister Eisaku Satō 's unilateral support of America's war in Vietnam, claiming "Realistically we are all guilty of complicity in
714-484: A more practically focused goal of finding "one chemical combination that would lend itself to industrial applications". It was not until the beginning of 1935 that a polymer called "polymer 6-6" was finally produced. Carothers' coworker, Washington University alumnus Julian W. Hill had used a cold drawing method to produce a polyester in 1930. This cold drawing method was later used by Carothers in 1935 to fully develop nylon. The first example of nylon (nylon 6.6)
833-598: A protest demonstration at sea against scheduled land reclamation work for the relocation of a U.S. military base within Japan's southernmost island prefecture. A protest gathered hundreds of people. Since the early 2000s, Okinawans have opposed the presence of American troops helipads in the Takae zone of the Yanbaru forest near Higashi and Kunigami . This opposition grew in July 2016 after
952-495: A range of blends to be made. The two polymers can react with one another by transamidation to form random copolymers. According to their crystallinity, polyamides can be: According to this classification, PA66, for example, is an aliphatic semi-crystalline homopolyamide. All nylons are susceptible to hydrolysis , especially by strong acids , a reaction essentially the reverse of their synthesis. The molecular weight of nylon products so attacked drops, and cracks form quickly at
1071-567: A result of air pollution, attributing it to London smog in 1952, as well as poor air quality in New York and Los Angeles. The solution found to problems with pure nylon fabric was to blend nylon with other existing fibers or polymers such as cotton , polyester , and spandex . This led to the development of a wide array of blended fabrics. The new nylon blends retained the desirable properties of nylon (elasticity, durability, ability to be dyed) and kept clothes prices low and affordable. As of 1950,
1190-560: A result, the media has drawn renewed interest in the Ryukyu independence movement . Documents declassified in 1997 proved that both tactical and strategic weapons have been maintained in Okinawa. In 1999 and 2002, the Japan Times and the Okinawa Times reported speculation that not all weapons were removed from Okinawa. On October 25, 2005, after a decade of negotiations, the governments of
1309-650: A separate nation until 1879, Okinawan language and culture differ in many ways from those of mainland Japan. There remain six Ryukyuan languages which, although related, are incomprehensible to speakers of Japanese . One of the Ryukyuan languages is spoken in Kagoshima Prefecture , rather than in Okinawa Prefecture. These languages are in decline as the younger generation of Okinawans uses Standard Japanese. Mainland Japanese and some Okinawans generally perceive
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#17330853920641428-409: A series of crimes involving American troops in Japan, including the rape of a young girl of 14 by a Marine on Okinawa. The U.S. military imposed a temporary 24-hour curfew on military personnel and their families to ease the anger of local residents. Some cited statistics that the crime rate of military personnel is consistently less than that of the general Okinawan population. However, some criticized
1547-407: A third of the barrels developed leaks have led Okinawans to ask for environmental investigations, but as of 2012 both Tokyo and Washington refused such action. Jon Mitchell has reported concern that the U.S. used American Marines as chemical-agent guinea pigs. On September 30, 2018, Denny Tamaki was elected as the next governor of Okinawa prefecture, after a campaign focused on sharply reducing
1666-777: A variety as Doumaki, many made to match. The finishing touch, and arguably 'the Soul' of every Sanshin, is the Doumaki- the decorative textile that surrounds the head of the Sanshin. Dou, meaning 'drum' and Maki, meaning 'Wrap'. Most often, Doumaki are made from modern fibers and methods, and display the Royal Crest of the Ryukyu Kingdom (Hidari Gomon), in rich black and gold. These days, a wide variety of both modern-made and traditional hand-woven Doumaki can be found both in Japan and by world citizens via
1785-420: A variety of colors, to match a variety of Doumaki. Karakui, the tuning pegs, are generally made with whatever wood the neck is made from, but Ebony is most common, and desired for its strength. Acting much like the tuning pegs of the violin, cello, and other traditional western wood string instruments- Karakui will require the use of Rosin (made of Pine resin, oils, ash, etc.), after an initial period. The Rosin
1904-687: A wide variety of additives. Many kinds of nylon are known. One family, designated nylon-XY, is derived from diamines and dicarboxylic acids of carbon chain lengths X and Y, respectively. An important example is nylon-6,6 (C₁₂H₂₂N₂O₂). Another family, designated nylon-Z, is derived from aminocarboxylic acids with carbon chain length Z. An example is nylon-[6]. Nylon polymers have significant commercial applications in fabric and fibers (apparel, flooring and rubber reinforcement), in shapes (molded parts for cars, electrical equipment, etc.), and in films (mostly for food packaging ). Researchers at DuPont began developing cellulose-based fibers, culminating in
2023-455: A year after its launch, a second plant was opened in Martinsville, Virginia, to meet the growing demand and ensure a steady supply of this popular fabric. This expansion underscored the profound impact nylon had on the textile industry and its rapid rise to prominence as a versatile and sought-after material. While nylon was marketed as the durable and indestructible material of the people, it
2142-402: Is a sanshin in most Okinawan homes. It is the center of small informal family gatherings, weddings, birthdays, other celebrations, community parties, festivals. The sanshin is held in great respect among the Ryukyuan culture, and is often viewed as an instrument that carries the voice of the deities, and is regarded as a deity itself. This is reflected in the traditional construction of
2261-661: Is a radio-news program in the language as well. Okinawans have traditionally followed Ryukyuan religious beliefs, generally characterized by ancestor worship and the respecting of relationships between the living, the dead, and the gods and spirits of the natural world. Nylon Nylon is a family of synthetic polymers with amide backbones, usually linking aliphatic or semi-aromatic groups. Nylons are white or colorless and soft; some are silk -like. They are thermoplastic , which means that they can be melt-processed into fibers, films , and diverse shapes. The properties of nylons are often modified by blending with
2380-509: Is applicable for preparation of nylon 1,6 from adiponitrile , formaldehyde and water. Additionally, nylons can be synthesized from diols and dinitriles using this method as well. It is easy to make mixtures of the monomers or sets of monomers used to make nylons to obtain copolymers. This lowers crystallinity and can therefore lower the melting point. Some copolymers that have been or are commercially available are listed below: Most nylon polymers are miscible with each other allowing
2499-560: Is applied as a thin and tacky layer, adding grip between the two wood pieces. Karakui are infamous for breaking with the slightest impetus, and are therefore readily available individually or in sets of 3. Karakui also act as another face of expression for the Sanshin- they can be carved in a variety of different styles and designs, and finished in a range of colors, textures, and some can even be 'tipped' with Jade, Coral, or other stones, shells, and natural decorations. Another part of Sanshin's body
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#17330853920642618-458: Is derived from "New York" and "London"; however, no organisation in London was ever involved in the research and production of nylon. Nylon’s popularity soared in the 1940s and 1950s due to its durability and sheerness. In the 1970s, it became more popular due to its flexibility and price. In spite of oil shortages in the 1970s, consumption of nylon textiles continued to grow by 7.5% per year between
2737-603: Is higher than the cost of the Kits themselves. A unique 'evolutionary-tangent' of the Sanshin came about just after the Battle of Okinawa- the deadliest action in the Pacific War. Civilians were corralled into US camps following the Battle, during the US take-over. The Okinawans, allowed to bring nothing with them, insisted upon carrying on musical and dancing arts so important to their culture. With
2856-707: Is rather split. According to a telephone poll conducted by Lim John Chuan-tiong (林泉忠), an associate professor with the University of the Ryukyus , 40.6% of respondents identified as " 沖縄人 (Okinawan)", 21.3% identified as " 日本人 (Japanese)" and 36.5% identified as both. Okinawa prefecture age pyramid as of 1 October 2003 (per thousands of people) Okinawa Prefecture age pyramid, divided by sex, as of 1 October 2003 (per thousands of people) Per Japanese census data, Okinawa prefecture has had continuous positive population growth since 1960. Having been
2975-409: Is still good practice to maintain regular oiling of the reinforced kyoka-bari skin to prevent over-drying and cracking. There are also tailor-made products available to avoid skin-breakage, such as naturally oily leather circular pads that are placed on either side of the sanshin body during case storage. This prevents over-drying which leads to breaking. The wooden parts of the sanshin -
3094-460: Is susceptible to damage- and that is the head, or 'Ten'. It can be scratched, dented, or even completely broken off, if mishandled. A textile, simply called a Ten cover, is a small, elastic-reinforced slip-cover that is generally padded and quilted, to provide a bit of protection against surface damage. These Ten covers can be used at all times, or can be removed during play. Use during play will not effect sound quality. Ten covers come in as big of
3213-662: Is the 'New Wood' Sanshin- an instrument that abandons any type of 'skinning' of the body, and instead utilizes a thin panel of wood composite. This wood face is then finished and decorated in any number of fashions. This 'New Wood' design has pioneered the seemingly popular 'Sanshin Kit'. This 'DIY' kit generally includes pre-fabricated parts- the Sao/Neck, the Dou/drum head base, and the Karakui/tuning pegs- all of which come 'unfinished', awaiting
3332-577: Is the southernmost and westernmost prefecture of Japan . It has a population of 1,457,162 (as of 2 February 2020 ) and a geographic area of 2,281 km (880 sq mi ). Naha is the capital and largest city, with other major cities including Okinawa , Uruma , and Urasoe . Okinawa Prefecture encompasses two thirds of the Ryukyu Islands , including the Okinawa , Daitō and Sakishima groups, extending 1,000 kilometres (620 mi) southwest from
3451-489: The sanshin 's construction allows for it to be fully disassembled, re-skinned, and reassembled, usually with little time, cost, and inconvenience, as a number of sanshin craftsmen were heavily dotted throughout the Prefecture. When sanshin began to be exported across the world, skin breakages became a more prevalent issue, as no sanshin craftsmen existed outside of Okinawa, with Western luthiers unfamiliar with
3570-458: The sanshin 's popularity rapidly expanding all over the world, and the desire of players to have the most traditional sanshin possible, a hybrid skin known as the kyoka-bari style has been developed: a natural python skin is fitted to the sanshin and stretched with a strong, synthetic reinforcement fabric underneath. This proves a great compromise for those in dryer/colder/hotter climates. Like with its un-reinforced predecessor, it
3689-399: The sanshin . Sanshin are generally designed to last more than a lifetime, as they are often passed down through the generations of a family. A traditional Okinawan story, the tale of the 'Husband and Wife Sanshin ', tells of a pair of sanshin made from the same core of Okinawan Ebony tree. They were owned by a husband and wife prior to World War II . At the onset of the war,
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3808-709: The Imperial Chinese tributary system under the Ming dynasty beginning in the 15th century, which established economic relations between the two nations. In 1609, the Shimazu clan , which controlled the region that is now Kagoshima Prefecture , invaded the Ryukyu Kingdom . The Ryukyu Kingdom was obliged to agree to form a suzerain - vassal relationship with the Satsuma and the Tokugawa shogunate , while maintaining its previous role within
3927-851: The Invasion of Ryukyu in 1609. Okinawa was officially founded in 1879 by the Empire of Japan after seven years as the Ryukyu Domain , the last domain of the Han system . Okinawa was occupied by the United States during the Allied occupation of Japan after World War II and was governed by the Military Government of the Ryukyu Islands from 1945 to 1950 and Civil Administration of the Ryukyu Islands from 1950 until
4046-628: The Iriomote-Ishigaki , Kerama Shotō , and Yambaru National Parks; Okinawa Kaigan and Okinawa Senseki Quasi-National Parks; and Irabu , Kumejima , Tarama , and Tonaki Prefectural Natural Parks. The dugong is an endangered marine mammal related to the manatee . Iriomote is home to one of the world's rarest and most endangered cat species, the Iriomote cat . The region is also home to at least one endemic pit viper , Trimeresurus elegans . The islands of Okinawa are surrounded by some of
4165-575: The National Diet ( 国会 ) which had been established in 1890. On 1 April 1945, the U.S. Army and Marine Corps launched an invasion of Okinawa with 185,000 troops. They were faced with fanatical resistance from the Japanese defenders. A third of Okinawa's civilian population were killed during the ensuing fighting. The dead, of all nationalities, are commemorated at the Cornerstone of Peace . After
4284-716: The Paleolithic era were unearthed from a site in Naha, but the artifact was lost in transportation before it was examined. Japanese Jōmon influences are dominant on the Okinawa Islands , although clay vessels on the Sakishima Islands have a commonality with those in Taiwan. The first mention of the word Ryukyu was written in the Book of Sui . Okinawa was the Japanese word identifying
4403-637: The Satsunan Islands of Kagoshima Prefecture to Taiwan ( Hualien and Yilan Counties ). Okinawa Prefecture's largest island, Okinawa Island , is the home to a majority of Okinawa's population. Okinawa's indigenous ethnic group is the Ryukyuan people , who also live in the Amami Islands of Kagoshima Prefecture . Okinawa was ruled by the Ryukyu Kingdom from 1429 and unofficially annexed by Japan after
4522-486: The Southeast Botanical Gardens represent tropical plant species. The island is largely composed of coral , and rainwater filtering through that coral has given the island many caves, which played an important role in the Battle of Okinawa. Gyokusendo is an extensive limestone cave in the southern part of Okinawa's main island. The island experiences temperatures above 20 °C (68 °F) for most of
4641-544: The Three Non-Nuclear Principles reflected this popular opposition. Most of the weapons were alleged to be stored in ammunition bunkers at Kadena Air Base. Between 1954 and 1972, 19 different types of nuclear weapons were deployed in Okinawa, but with fewer than around 1,000 warheads at any one time. In fall 1960, U.S. commandos in Green Light Teams secret training missions carried small nuclear weapons on
4760-525: The acid and the base to neutralize each other. The salt is crystallized to purify it and obtain the desired precise stoichiometry. Heated to 285 °C (545 °F), the salt reacts to form nylon polymer with the production of water. Nylon 510, made from pentamethylene diamine and sebacic acid, was included in the Carothers patent to nylon 66 Nylon 610 is produced similarly using hexamethylene diamine. These materials are more expensive because of
4879-463: The "Keystone of the Pacific". This slogan was imprinted on local U.S. military license plates. In 1969, chemicals leaked from the U.S. storage depot at Chibana in central Okinawa, under Operation Red Hat . Evacuations of residents took place over a wide area for two months. Even two years later, government investigators found that Okinawans and the environment near the leak were still suffering because of
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4998-523: The 16th century, the sanshin reached the Japanese trading port at Sakai in Osaka , Japan . In mainland Japan, it evolved into the larger shamisen , and many people refer to the sanshin as jabisen ( 蛇皮線 , lit., " snake -skin strings") or jamisen ( 蛇三線 , "snake three strings") due to its snakeskin covering. The sanshin is considered the soul of Okinawan folk music. Played by youth as young as 2, to older people aged 100 or more, there
5117-467: The 1868 Meiji Restoration , the Japanese government, through military incursions, officially annexed the kingdom and renamed it Ryukyu han . At the time, the Qing dynasty asserted a nominal suzerainty over the islands. Ryukyu han became Okinawa Prefecture of Japan in 1879, even though all other hans had become prefectures of Japan in 1872. In 1912, Okinawans first obtained the right to vote for representatives to
5236-478: The 1960s and 1980s. Overall production of synthetic fibers, however, dropped from 63% of the worlds textile production in 1965, to 45% of the world's textile production in early 1970s. The appeal of "new" technologies wore off, and nylon fabric "was going out of style in the 1970s". Also, consumers became concerned about environmental costs throughout the production cycle: obtaining the raw materials (oil), energy use during production, waste produced during creation of
5355-472: The Chinese tributary system; Ryukyuan sovereignty was maintained since complete annexation would have created a conflict with China. The Satsuma clan earned considerable profits from trade with China during a period in which foreign trade was heavily restricted by the shogunate. Although Satsuma maintained strong influence over the islands, the Ryukyu Kingdom maintained a considerable degree of domestic political freedom for over two hundred years. Four years after
5474-666: The Department of Rayon. Some of the key ingredients of nylon had to be produced using high pressure chemistry , the main area of expertise of the Ammonia Department. Nylon was considered a "godsend to the Ammonia Department", which had been in financial difficulties. The reactants of nylon soon constituted half of the Ammonia Department's sales and helped them come out of the period of the Great Depression by creating jobs and revenue at DuPont. DuPont's nylon project demonstrated
5593-469: The Melvin Price Report, by 1955, the military had displaced 250,000 residents. Since 1960, the U.S. and Japan have maintained an agreement that allows the U.S. to secretly bring nuclear weapons into Japanese ports. The Japanese people tended to oppose the introduction of nuclear arms into Japanese territory and the Japanese government's assertion of Japan's non-nuclear policy and a statement of
5712-650: The New York Quartermaster Procurement Agency (NYQMPA), which developed and tested textiles for the Army and Navy , had committed to developing a wool-nylon blend. They were not the only ones to introduce blends of both natural and synthetic fibers. America's Textile Reporter referred to 1951 as the "Year of the blending of the fibers". Fabric blends included mixes like "Bunara" (wool-rabbit-nylon) and "Casmet" (wool-nylon-fur). In Britain, in November 1951,
5831-477: The Okinawa Prefecture: (name in brackets) These are the towns and villages in each district : (name in brackets) ( Kunigami ) Yunoon ( Yaeyama ) The indigenous Ryukyuan people make up the majority of Okinawa Prefecture's population and are also the main ethnic group of the Amami Islands to the north. Large Okinawan diaspora communities persist in places such as South America and Hawaii . With
5950-499: The Okinawan forest. Later, they were dug up, and brought back to their rightful home, having made it safely through the violent war. They are currently preserved by the son of the couple. Traditionally, the sanshin was covered with the skin of the Burmese python , but today, due to CITES regulations , the skin of the reticulated python is also used. Python skin is used for the skin of
6069-522: The Okinawan population wanted the complete closure of the U.S. bases, 42% wanted reduction, and 11% wanted to maintain status quo. Okinawan feelings about the U.S. military are complex, and some of the resentment towards the U.S. bases is directed towards the government in Tokyo , perceived as being insensitive to Okinawan needs and using Okinawa to house bases not desired elsewhere in Japan. In early 2008, U.S. Secretary of State Condoleezza Rice apologized after
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#17330853920646188-454: The Ryukyuan languages as "dialects". Standard Japanese is almost always used in formal situations. In informal situations, de facto everyday language among Okinawans under age 60 is Okinawa-accented mainland Japanese (" Okinawan Japanese "), which is often mistaken by non-Okinawans as the Okinawan language proper. The actual traditional Okinawan language is still used in traditional cultural activities, such as folk music and folk dance . There
6307-656: The U.S. and Japan officially agreed to move Marine Corps Air Station Futenma from its location in the densely populated city of Ginowan to the more northerly and remote Camp Schwab in Nago by building a heliport with a shorter runway, partly on Camp Schwab land and partly running into the sea. The move is partly an attempt to relieve tensions between the people of Okinawa and the Marine Corps. Despite Okinawa prefecture constituting only 0.6% of Japan's land surface, in 2006 75% of all USFJ bases were located on Okinawa, occupying 18% of
6426-517: The U.S. forces relocation plan but in April 2010 indicated their interest in resolving the issue by proposing a modified plan. A study done in 2010 found that the prolonged exposure to aircraft noise around the Kadena Air Base and other military bases cause health issues such as a disrupted sleep pattern, high blood pressure, weakening of the immune system in children, and a loss of hearing. In 2011, it
6545-459: The U.S. military bases, earlier viewed as paternal post war protection, were increasingly seen as aggressive. The Vietnam War highlighted the differences between United States and Okinawa but showed a commonality between the islands and mainland Japan. As controversy grew regarding the alleged placement of nuclear weapons on Okinawa, fears intensified over the escalation of the Vietnam War. Okinawa
6664-641: The U.S. military presence on the island. In 2006, some 8,000 U.S. Marines were removed from the island and relocated to Guam . The move to Marine Corps Base Camp Blaz is expected to be completed in 2023. Japan paid for a majority of the cost to construct the new base. The U.S. still maintains Air Force, Marine, Navy, and Army military installations on the islands. These bases include Kadena Air Base , Camp Foster , Marine Corps Air Station Futenma , Camp Hansen , Camp Schwab , Torii Station , Camp Kinser , and Camp Gonsalves . The area of 14 U.S. bases are 233 square kilometres (90 sq mi), occupying 18% of
6783-603: The Vietnam War". The Beheiren became a more visible anti-war movement on Okinawa as the American involvement in Vietnam intensified. The movement employed tactics ranging from demonstrations to handing leaflets to soldiers, sailors, airmen and Marines directly, warning of the implications for a third World War. The U.S. military bases on Okinawa became a focal point for anti-Vietnam War sentiment. By 1969, over 50,000 American military personnel were stationed on Okinawa. United States Department of Defense began referring to Okinawa as
6902-407: The affected zones. Lower members of the nylons (such as nylon 6) are affected more than higher members such as nylon 12. This means that nylon parts cannot be used in contact with sulfuric acid for example, such as the electrolyte used in lead–acid batteries . When being molded, nylon must be dried to prevent hydrolysis in the molding machine barrel since water at high temperatures can also degrade
7021-410: The announcement of nylon, therefore he was never able to see his success. Nylon was first used commercially in a nylon- bristled toothbrush in 1938, followed more famously in women's stockings or "nylons" which were shown at the 1939 New York World's Fair and first sold commercially in 1940, whereupon they became an instant commercial success with 64 million pairs sold during their first year on
7140-486: The assistance of their US captors, and their rations, a new type of Sanshin was made- using a tin can, and most likely a broom pole. This changed everything for the downtrodden prisoners, bring a bit of peace and joy to their otherwise bleek situation. This war-born Sanshin is now called Kankara Sanshin, or 'Can-Sanshin, Can-shin, etc.'. It is also the subject of the 'DIY-Kit' approach to Sanshin Traditionally, players wear
7259-619: The base of the Dou (head), at the point where the end of the neck pole sticks out. A silk thread-piece, known as an Itokake or Genkake is fitted onto the wood piece, then the strings are individually attached to the 3 loops of the Itokake, using a simple draw-thru knot. The other end of the string are brought up the body and neck, and are the individually wound onto their respective pegs, called Karakui. Itokake, once only available in Gold color, are now being made in
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#17330853920647378-528: The black market for as high as $ 20. Once the war ended, the return of nylon was awaited with great anticipation. Although DuPont projected yearly production of 360 million pairs of stockings, there were delays in converting back to consumer rather than wartime production. In 1946, the demand for nylon stockings could not be satisfied, which led to the nylon riots . In one instance, an estimated 40,000 people lined up in Pittsburgh to buy 13,000 pairs of nylons. In
7497-427: The body of the instrument, in contrast to the cat or dogskin used traditionally on the shamisen . Though Okinawa is famous for the venomous habu viper, the habu is in fact too small for its skin to be used to make sanshin , and it is believed that the snakeskin for the sanshin has always been imported from Southeast Asia. Though the pythons used to make sanshin skins today are not an endangered species,
7616-410: The carboxylic acid(s). Subsequent use of cyclic and aromatic monomers required the use of letters or sets of letters. One number after "PA" or "Nylon" indicates a homopolymer which is monadic or based on one amino acid (minus H 2 O) as monomer: Two numbers or sets of letters indicate a dyadic homopolymer formed from two monomers: one diamine and one dicarboxylic acid. The first number indicates
7735-399: The chemical department would be composed of several small research teams that would focus on "pioneering research" in chemistry and would "lead to practical applications". Harvard instructor Wallace Hume Carothers was hired to direct the polymer research group. Initially he was allowed to focus on pure research, building on and testing the theories of German chemist Hermann Staudinger . He
7854-464: The construction of six new helipads. The islands comprising the prefecture are the southern two thirds of the archipelago of the Ryūkyū Islands ( 琉球諸島 , Ryūkyū-shotō ) . Okinawa's inhabited islands are typically divided into three geographical archipelagos. From northeast to southwest: Approximately 36% percent of the total land area of the prefecture was designated as natural parks , namely
7973-461: The construction of the instrument, or its use of natural skins. Sanshin exported to cold and/or dry countries have an increased vulnerability to skin cracks, tears and breaks, leading to the development of artificial sanshin skins made from a variety of materials, such as nylon and polyester . The quality, appearance, and price of these skins varies greatly, ranging from hard, thin-skinned, high-pitched and 'tinny'-sounding polyester skins, to
8092-496: The danger of claims such as "New Hosiery Held Strong as Steel" and "No More Runs", DuPont scaled back the terms of the original announcement, especially those stating that nylon would possess the strength of steel. Also, DuPont executives marketing nylon as a revolutionary man-made material did not at first realize that some consumers experienced a sense of unease and distrust, even fear, towards synthetic fabrics. A particularly damaging news story, drawing on DuPont's 1938 patent for
8211-449: The depot. On May 15, 1972, the U.S. government handed over the islands to Japanese administration. The 1995 kidnaping, beating, and rape of a 12-year-old girl by three U.S. servicemen triggered large protests in Okinawa. Reports by the local media of accidents and crimes committed by U.S. servicemen have reduced the local population's support for the U.S. military bases. A strong emotional response has emerged from certain incidents. As
8330-534: The difficulty of distinguishing faux snakeskin from real snakeskin makes transporting real-snakeskin ( hongawa ) sanshin internationally somewhat risky. Due to international wildlife protection treaties, it is not legal to export snakeskin-covered sanshin to some countries, such as the United Kingdom and the United States . There is some room for interpretation of this, in that the treaties specify that
8449-404: The east coast of Okinawa Island. Between 1965 and 1972, Okinawa was a key staging point for United States in its military operations directed towards North Vietnam. Along with Guam, it presented a geographically strategic launch pad for covert bombing missions over Cambodia and Laos. Anti- Vietnam War sentiment became linked politically to the movement for reversion of Okinawa to Japan. In 1965,
8568-682: The end of World War II, the United States set up the United States Military Government of the Ryukyu Islands administration, which ruled Okinawa for 27 years. During this "trusteeship rule", the United States established numerous military bases on the Ryukyu islands. The Ryukyu independence movement was an Okinawan movement that clamored against U.S. rule. During the Korean War , B-29 Superfortresses flew bombing missions over Korea from Kadena Air Base on Okinawa. The military buildup on
8687-418: The fabric were produced, marking a remarkable start for this innovative material.[8]: 100 The demand for nylon surged, particularly for nylon stockings, which became an instant sensation. During their first year on the market, an astounding 64 million pairs of nylon stockings were sold, reflecting the fabric's rapid integration into daily life and fashion.[8]: 101 Such was the success of nylon that in 1941, just
8806-407: The fiber, and eventual waste disposal of materials that were not biodegradable. Synthetic fibers have not dominated the market since the 1950s and 1960s. As of 2020 , the worldwide production of nylon is estimated at 8.9 million tons. Although pure nylon has many flaws and is now rarely used, its derivatives have greatly influenced and contributed to society. From scientific discoveries relating to
8925-461: The first case, the "repeating unit" has the ABAB structure, as also seen in many polyesters and polyurethanes . Since each monomer in this copolymer has the same reactive group on both ends, the direction of the amide bond reverses between each monomer, unlike natural polyamide proteins , which have overall directionality: C terminal → N terminal . In the second case (so called AA),
9044-404: The husband was forced into military service by the Japanese, and therefore had to leave his wife and home. Due to the destruction to main island during the war, the pair of sanshin were in danger, and the war wiped out almost half of the native population. In an attempt to preserve his and his wife's sanshin , the husband wrapped them up, put them into a wooden box, and buried them deep in
9163-407: The importance of chemical engineering in industry, helped create jobs, and furthered the advancement of chemical engineering techniques. In fact, it developed a chemical plant that provided 1800 jobs and used the latest technologies of the time, which are still used as a model for chemical plants today. The ability to acquire a large number of chemists and engineers quickly was a huge contribution to
9282-550: The inaugural address of the 198th session of the Royal Society for the Encouragement of Arts, Manufactures and Commerce focused on the blending of textiles. DuPont's Fabric Development Department cleverly targeted French fashion designers, supplying them with fabric samples. In 1955, designers such as Coco Chanel , Jean Patou , and Christian Dior showed gowns created with DuPont fibers, and fashion photographer Horst P. Horst
9401-551: The internet. They can range from US$ 10 (for traditional design and cheaper materials), all the way to US$ 175, for the magnificent hand-woven Doumaki, made with hand-spun silk or the famous Basho-fu, 'silk' made from the trunks of Okinawan Banana trees. These high-end Doumaki may also incorporate leather, python skin, Bingata fabric (Okinawan 'stencil & paste' dyeing), Minsaa weavings (traditional Ryukyu '4 & 5' Square patterns_ and other natural/modern materials. In addition to synthetic skins, another modern cost-cutting adaptation
9520-455: The introduction of American military bases, there are an increasing number of half-American children in Okinawa, including prefecture governor Denny Tamaki . The prefecture also has a sizable minority of Yamato people from mainland Japan; exact population numbers are difficult to establish, as the Japanese government does not officially recognise Ryukyuans as a distinct ethnic group from Yamatos. The overall ethnic identity of Okinawa residents
9639-404: The invention to Coca-Cola in the eyes of 20th century consumers. In common usage, the prefix "PA" ( polyamide ) or the name "Nylon" are used interchangeably and are equivalent in meaning. The nomenclature used for nylon polymers was devised during the synthesis of the first simple aliphatic nylons and uses numbers to describe the number of carbons in each monomer unit, including the carbon(s) of
9758-458: The island during the Cold War increased a division between local inhabitants and the American military. Under the 1952 Treaty of Mutual Cooperation and Security between the United States and Japan , United States Forces Japan (USFJ) have maintained a large military presence. During the mid-1950s, the U.S. seized land from Okinawans to build new bases or expand currently existing ones. According to
9877-522: The islands, first seen in the biography of Jianzhen , written in 779. Agricultural societies begun in the 8th century slowly developed until the 12th century. Since the islands are located at the eastern perimeter of the East China Sea relatively close to Japan, China and Southeast Asia , the Ryukyu Kingdom became a prosperous trading nation. Also during this period, many Gusukus , similar to castles, were constructed. The Ryukyu Kingdom entered into
9996-569: The main island. According to a 2007 Okinawa Times poll, 85% of Okinawans opposed the presence of the U.S. military, because of noise pollution from military drills, the risk of aircraft accidents, environmental degradation , and crowding from the number of personnel there, although 73% of Japanese citizens appreciated the mutual security treaty with the U.S. and the presence of the USFJ. In another poll conducted by The Asahi Shimbun in May 2010, 43% of
10115-482: The main island. Okinawa hosts about two-thirds of the 50,000 American forces in Japan although the islands account for less than one percent of total lands in Japan. Suburbs have grown towards and now surround two historic major bases, Futenma and Kadena. A sizeable portion of the land used by the U.S. military is Camp Gonsalves in the north of the island. On December 21, 2016, 10,000 acres of Camp Gonsalves were returned to Japan. On June 25, 2018, Okinawa residents held
10234-400: The market. During World War II, almost all nylon production was diverted to the military for use in parachutes and parachute cord . Wartime uses of nylon and other plastics greatly increased the market for the new materials. The production of nylon required interdepartmental collaboration between three departments at DuPont: the Department of Chemical Research, the Ammonia Department, and
10353-441: The meantime, women cut up nylon tents and parachutes left from the war in order to make blouses and wedding dresses. Between the end of the war and 1952, production of stockings and lingerie used 80% of the world's nylon. DuPont put focus on catering to the civilian demand, and continually expanded its production. As pure nylon hosiery was sold in a wider market, problems became apparent. Nylon stockings were found to be fragile, in
10472-455: The more 'snake-skin-sounding' nylon skins, which replicate the layered composition of natural snake skin. Artificially skinned sanshin are popular due to their generally low cost and their invulnerability to different temperatures and atmospheres. The highest-quality synthetic-skin sanshin , which are available for as low as US$ 300, are the go-to choice for professional Okinawan Folk Musicians who travel and play overseas. These days, with
10591-428: The most abundant coral reefs found in the world. The world's largest colony of rare blue coral is found off Ishigaki Island . The sea turtles return yearly to the southern islands of Okinawa to lay their eggs. The summer months carry warnings to swimmers regarding venomous jellyfish and other dangerous sea creatures. Okinawa is a major producer of sugar cane , pineapple , papaya , and other tropical fruit, and
10710-407: The name was originally intended to be "No-Run" ("run" meaning "unravel") but was modified to avoid making such an unjustified claim. Since the products were not really run-proof, the vowels were swapped to produce "nuron", which was changed to "nilon" "to make it sound less like a nerve tonic". For clarity in pronunciation, the "i" was changed to "y". A persistent urban legend exists that the name
10829-543: The national market until May 15, 1940. However, a limited number were released for sale in Delaware before that. The first public sale of nylon stockings occurred on October 24, 1939, in Wilmington, Delaware. 4,000 pairs of stockings were available, all of which were sold within three hours. Another added bonus to the campaign was that it meant reducing silk imports from Japan, an argument that won over many wary customers. Nylon
10948-524: The neck ( sao ), head/body ( dou ), and head ( ten - can be made with any of a large variety of hardwoods. Traditionally, the neck is crafted with the solid black core of the Okinawan Ebony tree, a species native to Okinawa, and the only ebony in the whole of Japan. This black ebony core is highly sought-after for its strength and its traditional sound quality. Typically, Ebony trees no younger than 100 years old are used in sanshin construction -
11067-531: The new owner's creative hands. Wood parts can be further sanded, stained/painted, oiled, lacquered, etc... whatever the heart desires. Kits come with a traditional Doumaki, but the die-hard artisan may choose to create their own unique, personally-designed textile. It seems that in recent times, with the US Dollar and the Japanese Yen not exactly being of equal value, the cost of shipping to countries outside of Asia,
11186-441: The new polymer, suggested that one method of producing nylon might be to use cadaverine (pentamethylenediamine), a chemical extracted from corpses. Although scientists asserted that cadaverine was also extracted by heating coal, the public often refused to listen. A woman confronted one of the lead scientists at DuPont and refused to accept that the rumour was not true. DuPont changed its campaign strategy, emphasizing that nylon
11305-581: The number of carbons in the diamine. The two numbers should be separated by a comma for clarity, but the comma is often omitted. For copolymers the comonomers or pairs of comonomers are separated by slashes: The term polyphthalamide (abbreviated to PPA) is used when 60% or more moles of the carboxylic acid portion of the repeating unit in the polymer chain is composed of a combination of terephthalic acid (TPA) and isophthalic acid (IPA). Nylon 66 and related polyamides are condensation polymers forms from equal parts of diamine and dicarboxylic acids . In
11424-551: The prefecture was returned to Japan in 1972. Okinawa comprises just 0.6 percent of Japan's total land mass, but about 26,000 (75%) of United States Forces Japan personnel are assigned to the prefecture; the continued U.S. military presence in Okinawa is controversial. The oldest evidence of human existence on the Ryukyu Islands is from the Stone Age and was discovered in Naha and Yaeyama . Some human bone fragments thought to be from
11543-457: The product was available to the general market. Nylon's commercial announcement occurred on October 27, 1938, at the final session of the Herald Tribune ' s yearly "Forum on Current Problems", on the site of the approaching New York City world's fair. The "first man-made organic textile fiber" which was derived from "coal, water and air" and promised to be "as strong as steel, as fine as
11662-476: The production of plastics and polymerization, to economic impact during the depression and the changing of women's fashion, nylon was a revolutionary product. The Lunar Flag Assembly , the first flag planted on the moon in a symbolic gesture of celebration, was made of nylon. The flag itself cost $ 5.50 but had to have a specially designed flagpole with a horizontal bar so that it would appear to "fly". One historian describes nylon as "an object of desire", comparing
11781-459: The relatively high cost of sebacic acid. Owing to the high hydrocarbon content, nylon 610 is more hydrophobic and finds applications suited for this property, such as bristles. Examples of these polymers that are or were commercially available: These polymers are made from a lactam or amino acid. The synthetic route using lactams (cyclic amides) was developed by Paul Schlack at IG Farben , leading to nylon 6, or polycaprolactam —formed by
11900-491: The repeating unit corresponds to the single monomer. Wallace Carothers at DuPont patented nylon 66 . In the case of nylons that involve reaction of a diamine and a dicarboxylic acid, it is difficult to get the proportions exactly correct, and deviations can lead to chain termination at molecular weights less than a desirable 10,000 daltons . To overcome this problem, a crystalline , solid "nylon salt " can be formed at room temperature , using an exact 1:1 ratio of
12019-410: The restriction is for endangered snake species. Naturally-skinned instruments - while considered unparalleled in sound quality, producing a warm, deep yet pronounced tone - are infamous for cracking and tearing, especially when the sanshin is taken out of its natural habitat, the humid tropicality of the Ryukyu Islands. Up until recent times, skin breakage was never considered much of a problem, as
12138-589: The sense that the thread often tended to unravel lengthwise, creating 'runs'. People also reported that pure nylon textiles could be uncomfortable due to nylon's lack of absorbency. Moisture stayed inside the fabric near the skin under hot or moist conditions instead of being "wicked" away. Nylon fabric could also be itchy and tended to cling and sometimes spark as a result of static electrical charge built up by friction. Also, under some conditions, stockings could decompose turning back into nylon's original components of air, coal, and water. Scientists explained this as
12257-562: The spider's web" was received enthusiastically by the audience, many of them middle-class women, and made the headlines of most newspapers. Nylon was introduced as part of "The world of tomorrow" at the 1939 New York World's Fair and was featured at DuPont's "Wonder World of Chemistry" at the Golden Gate International Exposition in San Francisco in 1939. Actual nylon stockings were not shipped to selected stores in
12376-435: The statistics as unreliable, since violence against women is under-reported. Between 1972 and 2009, U.S. servicemen committed 5,634 criminal offenses, including 25 murders, 385 burglaries, 25 arsons, 127 rapes, 306 assaults and 2,827 thefts. Yet, per Marine Corps Installations Pacific data, U.S. service members are convicted of far fewer crimes than local Okinawans. In 2009, a new Japanese government came to power and froze
12495-412: The strings are (from thick to thin) uujiru (男絃, "male string"), nakajiru (中絃, "middle string"), and miijiru (女絃, "female string"). The sanshin has five tunings called chindami ( ちんだみ ) : Sheet music for the sanshin is written in a unique transcription system called kunkunshi ( Okinawan : 工工四, pronounced [kuŋkunshiː] ). It is named for the first three notes of Chinese melody that
12614-532: The success of DuPont's nylon project. The first nylon plant was located at Seaford, Delaware, beginning commercial production on December 15, 1939. On October 26, 1995, the Seaford plant was designated a National Historic Chemical Landmark by the American Chemical Society . An important part of nylon's popularity stems from DuPont's marketing strategy. DuPont promoted the fiber to increase demand before
12733-459: The synthetic fiber rayon . DuPont's experience with rayon was an important precursor to its development and marketing of nylon. DuPont's invention of nylon spanned an eleven-year period, ranging from the initial research program in polymers in 1927 to its announcement in 1938, shortly before the opening of the 1939 New York World's Fair . The project grew from a new organizational structure at DuPont, suggested by Charles Stine in 1927, in which
12852-665: The time necessary for the tree to grow a big enough black core to produce one or more instrument necks. Instruments made with Okinawan Ebony are among the most expensive sanshin made and sold today. Even Ebony instruments that forego authentic snakeskin for the cheaper and more durable nylon and polyester skins can be several times more expensive than an instrument made with other hardwoods. The other, more common hardwoods (used mainly for convenience, availability, and cost-effectiveness) include Oak, Apitong, and Rosewoods (any number of species). There are 3 strings, called Gen. They can be made of Nylon or Silk. They are first attached to
12971-420: The use of garters to hold them up. However, as of February 11, 1942, nylon production was redirected from being a consumer material to one used by the military. DuPont's production of nylon stockings and other lingerie stopped, and most manufactured nylon was used to make parachutes and tents for World War II . Although nylon stockings already made before the war could be purchased, they were generally sold on
13090-473: The year. The climate of the islands ranges from humid subtropical climate ( Köppen climate classification Cfa ) in the north, such as Okinawa Island , to tropical rainforest climate (Köppen climate classification Af ) in the south such as Iriomote Island . Snowfall is unheard of at sea level. However, on January 24, 2016, sleet was reported in Nago for the first time on record. Eleven cities are located within
13209-401: Was even mentioned by President Roosevelt 's cabinet, which addressed its "vast and interesting economic possibilities" five days after the material was formally announced. However, the early excitement over nylon also caused problems. It fueled unreasonable expectations that nylon would be better than silk, a miracle fabric as strong as steel that would last forever and never run. Realizing
13328-536: Was hired to document their use of DuPont fabrics. American Fabrics credited blends with providing "creative possibilities and new ideas for fashions which had been hitherto undreamed of." DuPont went through an extensive process to generate names for its new product. In 1940, John W. Eckelberry of DuPont stated that the letters "nyl" were arbitrary, and the "on" was copied from the suffixes of other fibers such as cotton and rayon . A later publication by DuPont ( Context , vol. 7, no. 2, 1978) explained that
13447-443: Was made from "coal, air and water", and started focusing on the personal and aesthetic aspects of nylon, rather than its intrinsic qualities. Nylon was thus domesticated, and attention shifted to the material and consumer aspect of the fiber with slogans like "If it's nylon, it's prettier, and oh! How fast it dries!". After nylon's nationwide release in 1940, its production ramped up significantly. In that year alone, 1300 tons of
13566-431: Was perceived by some inside Japan as a potential target for China, should the communist government feel threatened by United States. American military secrecy blocked any local reporting on what was actually occurring at bases such as Kadena Air Base. As information leaked out, and images of air strikes were published, the local population began to fear the potential for retaliation. Political leaders such as Makoto Oda ,
13685-551: Was produced on February 28, 1935, at DuPont's research facility at the DuPont Experimental Station. It had all the desired properties of elasticity and strength. However, it also required a complex manufacturing process that would become the basis of industrial production in the future. DuPont obtained a patent for the polymer in September 1938, and quickly achieved a monopoly of the fiber. Carothers died 16 months before
13804-441: Was reported that the U.S. military—contrary to repeated denials by The Pentagon —had kept tens of thousands of barrels of Agent Orange on the island. The Japanese and American governments have angered some U.S. veterans, who believe they were poisoned by Agent Orange while serving on the island, by characterizing their statements regarding Agent Orange as "dubious", and ignoring their requests for compensation. Reports that more than
13923-429: Was sold at about one-and-a-half times the price of silk stockings ($ 4.27 per pound of nylon versus $ 2.79 per pound of silk). Sales of nylon stockings were strong in part due to changes in women's fashion. As Lauren Olds explains: "by 1939 [hemlines] had inched back up to the knee, closing the decade just as it started off". The shorter skirts were accompanied by a demand for stockings that offered fuller coverage without
14042-567: Was very successful, as research he undertook greatly improved the knowledge of polymers and contributed to the science. Nylon was the first commercially successful synthetic thermoplastic polymer. DuPont began its research project in 1927. The first nylon, nylon 66 , was synthesized on February 28, 1935, by Wallace Hume Carothers at DuPont's research facility at the DuPont Experimental Station . In response to Carothers' work, Paul Schlack at IG Farben developed nylon 6 ,
14161-451: Was widely known during its development. Its creator is believed to be Mongaku Terukina or his student Choki Yakabi ( 屋嘉比 朝寄 , Yakabi Chōki ) in the early to mid-1700s. A set of kanji are used to represent specific finger positions. Unlike European musical notation , kunkunshi can only be interpreted specifically through the sanshin. Okinawa Prefecture Okinawa Prefecture ( Japanese : 沖縄県 , Hepburn : Okinawa-ken )
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