title: Hegra (Mada'in Salih)

text: The extensive settlement of the site took place during the 1st century AD, when it came under the rule of the Nabatean king Aretas IV Philopatris (Al-Harith IV) (9 BC – 40 AD), who made Hegra (Mada’in Salih) the kingdom's second capital, after Petra in the north. The place enjoyed a huge urbanization movement, turning it into a city. Characteristic of Nabatean rock-cut architecture, the geology of Hegra (Mada’in Salih) provided the perfect medium for the carving of monumental structures, with Nabatean scripts inscribed on their façades. The Nabateans also developed oasis agriculture—digging wells and rainwater tanks in the rock and carving places of worship in the sandstone outcroppings. Similar structures were featured in other Nabatean settlements, ranging from southern Syria (region) to the north, going south to the Negev, and down to the immediate area of the Hejaz. The most prominent and the largest of these is Petra.


title: Hegra (Mada'in Salih)

text: At the crossroad of commerce, the Nabatean kingdom flourished, holding a monopoly for the trade of incense, myrrh and spices. Situated on the overland caravan route and connected to the Red Sea port of Egra Kome, Hegra, as it was known among the Nabateans, reached its peak as the major staging post on the main north–south trade route.


title: Hegra (Mada'in Salih)

text: In 106 AD, the Nabatean kingdom was annexed by the contemporary Roman Empire. The Hejaz, which encompasses Hegra, became part of the Roman province of Arabia.


title: Hegra (Mada'in Salih)

text: The trading itinerary shifted from the overland north–south axis on the Arabian Peninsula to the maritime route through the Red Sea. Thus, Hegra as a center of trade began to decline, leading to its abandonment. Supported by the lack of later developments based on archaeological studies, experts have hypothesized that the site had lost all of its urban functions beginning in the late Antiquity (mainly due to the process of desertification). In the 1960s and 1970s, evidence was discovered that the Roman legions of Trajan occupied Mada'in Salih in northeastern Arabia, increasing the extension of the Arabia Petraea province of the Romans in Arabia.


title: Hegra (Mada'in Salih)

text: The history of Hegra, from the decline of the Roman Empire until the emergence of Islam, remains unknown. It was only sporadically mentioned by travelers and pilgrims making their way to Mecca in the succeeding centuries. Hegra served as a station along the Hajj route, providing supplies and water for pilgrims. Among the accounts is a description made by 14th-century traveler Ibn Battuta, noting the red stone-cut tombs of Hegra, by then known as "al-Hijr." However, he made no mention of human activities there.


title: Hegra (Mada'in Salih)

text: The Ottoman Empire annexed western Arabia from the Mamluks by 1517. In early Ottoman accounts of the Hajj road between Damascus and Mecca, Hegra (Mada’in Salih) is not mentioned, until 1672, when the Turkish traveler, Evliya Celebi noted that the caravan passed through a place called "Abyar Salih" where there were the remains of seven cities. It is again mentioned by the traveler Murtada ibn 'Alawan as a rest stop on the route called "al-Mada'in." Between 1744 and 1757, a fort was built at al-Hijr on the orders of the Ottoman governor of Damascus, As'ad Pasha al-Azm. A cistern supplied by a large well within the fort was also built, and the site served as a one-day stop for Hajj pilgrims where they could purchase goods such as dates, lemons and oranges. It was part of a series of fortifications built to protect the pilgrimage route to Mecca.


title: Hegra (Mada'in Salih)

text: According to the researches of Al-Ansari, the Ottoman castle was found near the settlement dating to the year 1600 A.D in 1984


title: Hegra (Mada'in Salih)

text: Following the discovery of Petra by the Swiss explorer Johann Ludwig Burckhardt in 1812, Charles Montagu Doughty, an English traveler, heard of a similar site near Hegra (Mada’in Salih), a fortified Ottoman town on the Hajj road from Damascus. In order to access the site, Doughty joined the Hajj caravan, and reached the site of the ruins in 1876, recording the visit in his journal which was published as "Travels in Arabia Deserta". Doughty described the Ottoman fort, where he resided for two months, and noted that Bedouin tribesmen had a permanent encampment just outside of the building.


title: Hegra (Mada'in Salih)

text: In the 19th century, there were accounts that the extant wells and oasis agriculture of al-Hijr were being periodically used by settlers from the nearby village of Tayma. This continued until the 20th century, when the Hejaz Railway that passed through the site was constructed (1901–08) on the orders of Ottoman sultan Abdul Hamid II to link Damascus and Jerusalem in the north-west with Medina and Mecca, hence facilitating the pilgrimage journey to the latter and to politically and economically consolidate the Ottoman administration of the centers of Islamic faith. A station was built north of al-Hijr for the maintenance of locomotives, and offices and dormitories for railroad staff. The railway provided greater accessibility to the site. However, this was destroyed in a local revolt during World War I. Despite this, several archaeological investigations continued to be conducted in the site beginning in the World War I period to the establishment of the Kingdom of Saudi Arabia in the 1930s up to the 1960s. The railway station has also been restored and now includes 16 buildings and several pieces of rolling stock.


title: Hegra (Mada'in Salih)

text: By the end of the 1960s, the Saudi Arabian government devised a program to introduce a sedentary lifestyle to the nomadic Bedouin tribes inhabiting the area. It was proposed that they settle down in al-Hijr, re-using the already existent wells and agricultural features of the site. However, the official identification of al-Hijr as an archaeological site in 1972 led to the resettlement of the Bedouins towards the north, beyond the site boundary. This also included the development of new agricultural land and freshly dug wells, thereby preserving the state of al-Hijr.


title: Hegra (Mada'in Salih)

text: In 1962, examples of many inscriptions were discovered and renewed the archaeological assessment of Hijr (Mada’in Salih) by Winnett and Reed. Although the Al-Hijr site was proclaimed as an archaeological treasure in the early 1970s, few investigations had been conducted since. Mirdad had lived here for a short time and wrote notices about the region since 1977. Healey studied here in 1985 and wrote a book about the inscriptions of Hijr (Mada’in Salih) in 1993.


title: Hegra (Mada'in Salih)

text: The prohibition on the veneration of objects/artifacts has resulted in minimal archaeological activities. These conservative measures started to ease up beginning in 2000, when Saudi Arabia invited expeditions to carry out archaeological explorations as part of the government's push to promote cultural heritage protection and tourism. The archaeological site was proclaimed as a UNESCO World Heritage Site in 2008. More recent archaeological studies of the area have been made as part of efforts to document and preserve the heritage sites prior to opening the area to more tourism.


title: Hegra (Mada'in Salih)

text: The Nabatean site of Hegra was built around a residential zone and its oasis during the 1st century CE. The sandstone outcroppings were carved to build the necropolis. A total of four necropolis sites have survived, which featured 131 monumental rock-cut tombs spread out over , many with inscribed Nabatean epigraphs on their façades:


title: Hegra (Mada'in Salih)

text: Non-monumental burial sites, totaling 2,000, are also part of the place. A closer observation of the façades indicates the social status of the buried person—the size and ornamentation of the structure reflect the wealth of the person. Some façades had plates on top of the entrances providing information about the grave owners, the religious system, and the masons who carved them. Many graves indicate military ranks, leading archaeologists to speculate that the site might once have been a Nabatean military base, meant to protect the settlement's trading activities.


title: Hegra (Mada'in Salih)

text: The Nabatean kingdom was not just situated at the crossroad of trade but also of culture. This is reflected in the varying motifs of the façade decorations, borrowing stylistic elements from Assyria, Phoenicia, Egypt and Hellenistic Alexandria, combined with the native artistic style. Roman decorations and Latin scripts also figured on the troglodytic tombs when the territory was annexed by the Roman Empire. In contrast to the elaborate exteriors, the interiors of the rock-cut structures are severe and plain.


title: Hegra (Mada'in Salih)

text: A religious area, known as ""Jabal Ithlib"," is located to the north-east of the site. It is believed to have been originally dedicated to the Nabatean deity Dushara. A narrow corridor, long between the high rocks and reminiscent of the Siq in Petra, leads to the hall of the "Diwan", a Muslim's council-chamber or law-court. Small religious sanctuaries bearing inscriptions were also cut into the rock in the vicinity.


title: Hegra (Mada'in Salih)

text: The residential area is located in the middle of the plain, far from the outcrops. The primary material of construction for the houses and the enclosing wall was sun-dried mudbrick. Few vestiges of the residential area remain.


title: Hegra (Mada'in Salih)

text: Water is supplied by 130 wells, situated in the western and north-western part of the site, where the water table was at a depth of only . The wells, with diameters ranging , were cut into the rock, although some, dug in loose ground, had to be reinforced with sandstone.


title: Hegra (Mada'in Salih)

text: The archaeological site lies in an arid environment. The dry climate, the lack of resettlement after the site was abandoned, and the prevailing local beliefs about the locality have all led to the extraordinary state of preservation of Al-Hijr, providing an extensive picture of the Nabatean lifestyle. Thought to mark the southern extent of the Nabatean kingdom, Al-Hijr's oasis agriculture and extant wells exhibit the necessary adaptations made by the Nabateans in the given environment—its markedly distinct settlement is the second largest among the Nabatean kingdom, complementing that of the more famous Petra archaeological site in Jordan. The location of the site at the crossroads of trade, as well as the various languages, scripts and artistic styles reflected in the façades of its monumental tombs further set it apart from other archaeological sites. It has duly earned the nickname "The Capital of Monuments" among Saudi Arabia's 4,000 archaeological sites.


title: Breast hypertrophy

text: Breast hypertrophy is a rare medical condition of the breast connective tissues in which the breasts become excessively large. The condition is often divided based on the severity into two types, macromastia and gigantomastia. Hypertrophy of the breast tissues may be caused by increased histologic sensitivity to certain hormones such as female sex hormones, prolactin, and growth factors. Breast hypertrophy is a benign "progressive" enlargement, which can occur in both breasts (bilateral) or only in one breast (unilateral). It was first scientifically described in 1648.


title: Breast hypertrophy

text: The indication is an excess breast weight that exceeds approximately 3% of the total body weight. There are varying definitions of what is considered to be excessive breast tissue, that is the expected breast tissue plus extraordinary breast tissue, ranging from as little as up to with most physicians defining macromastia as excessive tissue of over . Some resources distinguish between macromastia (Greek, "macro": large, "mastos": breast), where excessive tissue is less than 2.5 kg, and gigantomastia (Greek, "gigantikos": giant), where excessive tissue is more than 2.5 kg. The enlargement can cause muscular discomfort and over-stretching of the skin envelope, which can lead in some cases to ulceration.


title: Breast hypertrophy

text: Hypertrophy of the breast can affect the breasts equally, but usually affects one breast more than the other, thereby causing asymmetry, when one breast is larger than the other. The condition can also individually affect the nipples and areola instead of or in addition to the entire breast. The effect can produce a minor size variation to an extremely large breast asymmetry. Breast hypertrophy is classified in one of five ways: as either pubertal (virginal hypertrophy), gestational (gravid macromastia), in adult women without any obvious cause, associated with penicillamine therapy, and associated with extreme obesity. Many definitions of macromastia and gigantomastia are based on the term of "excessive breast tissue", and are therefore somewhat arbitrary.


title: Breast hypertrophy

text: When gigantomastia occurs in young women during puberty, the medical condition is known as "juvenile macromastia" or "juvenile gigantomastia" and sometimes as "virginal breast hypertrophy" or "virginal mammary hypertrophy". Along with the excessive breast size, other symptoms include red, itchy lesions and pain in the breasts. A diagnosis is made when an adolescent's breasts grow rapidly and achieve great weight, usually soon after her first menstrual period. Some doctors suggest that the rapid breast development occurs before the onset of menstruation.


title: Breast hypertrophy

text: Some women with virginal breast hypertrophy experience breast growth at a steady rate for several years, after which the breasts rapidly develop exceeding normal growth. Some adolescent females experience minimal or negligible breast growth until their breasts suddenly grow very rapidly in a short period of time. This may cause considerable physical discomfort. Women with VBH often experience an excessive growth of their nipples as well. In severe cases of VBH, hypertrophy of the clitoris occurs.


title: Breast hypertrophy

text: At the onset of puberty, some females with who have experienced little or no breast development can reportedly reach three or more cup sizes within a few days (see below).


title: Breast hypertrophy

text: This same effect can also occur at the onset of pregnancy or between the 16th to 20th week of gestation. When the swelling in the connective tissue occurs after birth, it can negatively impact long term milk supply. The swelling increases with each subsequent pregnancy.


title: Breast hypertrophy

text: The extremely rapid growth of the breasts can result in intense heat. The woman's breasts can generate extraordinary discomfort, turning feverish, red, itchy, and even causing the skin to peel. The swelling can suppress the milk supply, pinching off the milk ducts, and leading to mastitis.


title: Breast hypertrophy

text: Breast size in women with gestational breast hypertrophy typically reverts to approximately pre-pregnancy size or near it after pregnancy and cessation of breastfeeding. This is not always the case however and in some only partial reduction in breast size may occur, necessitating surgical breast reduction.


title: Breast hypertrophy

text: Only 15% of cases of breast hypertrophy are unrelated to puberty or pregnancy. Other types and causes of breast hypertrophy include idiopathic, drug-induced (e.g., penicillamine, cyclosporine, bucillamine), autoimmunity-associated, tumors, and syndromes. Two case reports of prepubertal breast hypertrophy, both in infants, have been reported.


title: Breast hypertrophy

text: The underlying cause of the rapidly growing breast connective tissue, resulting in gigantic proportions, has not been well elucidated. However, proposed factors have included increased levels/expression of or heightened sensitivity to certain hormones (e.g., estrogen, progesterone, and prolactin) and/or growth factors (e.g., hepatocyte growth factor, insulin-like growth factor 1, and epidermal growth factor) in the breasts. Macromastic breasts are reported to be composed mainly of adipose and fibrous tissue, while glandular tissue remains essentially stable.


title: Breast hypertrophy

text: Macromastia occurs in approximately half of women with aromatase excess syndrome (a condition of hyperestrogenism). Hyperprolactinemia has been reported as a cause of some cases of macromastia. Macromastia has also been associated with hypercalcemia (which is thought to be due to excessive production of parathyroid hormone-related protein) and, rarely, systemic lupus erythematosus and pseudoangiomatous stromal hyperplasia. It is also notable that approximately two-thirds of women with macromastia are obese. Aside from aromatase (as in aromatase excess syndrome), at least two other genetic mutations (one in PTEN) have been implicated in causing macromastia.


title: Breast hypertrophy

text: A handful of drugs have been associated with gigantomastia, including penicillamine, bucillamine, neothetazone, ciclosporin, indinavir, and prednisolone.


title: Breast hypertrophy

text: Medical treatment has not proven consistently effective. Medical regimens have included tamoxifen, progesterone, bromocriptine, the gonadotropin-releasing hormone agonist leuprorelin, and testosterone. Gestational macromastia has been treated with breast reduction drugs alone without surgery. Surgical therapy includes reduction mammaplasty and mastectomy. However, breast reduction is not clinically indicated unless at least 1.8 kg (4 lb) of tissue per breast needs to be removed. In the majority of cases of macromastia, surgery is medically unnecessary, depending on body height. Topical treatment includes regimens of ice to cool the breasts.


title: Breast hypertrophy

text: Treatment of hyperprolactinemia-associated macromastia with D receptor agonists such as bromocriptine and cabergoline has been found to be effective in some, but not all cases. Danazol, an antiestrogen and weak androgen, has also been found to be effective in the treatment of macromastia.


title: Breast hypertrophy

text: When hypertrophy occurs in adolescence, noninvasive treatments, including pharmaceutical treatment, hormone therapy, and steroid use are not usually recommended due to known and unknown side effects. Once breast growth rate has stabilized, breast reduction may be an appropriate choice. In some instances after aggressive or surgical treatment, the breast may continue to grow or re-grow, a complete mastectomy may be recommended as a last resort.


title: Breast hypertrophy

text: Pregnancy is recognized as the second most common reason for hypertrophy. When secondary to pregnancy, it may resolve itself without treatment after the pregnancy ends.


title: Breast hypertrophy

text: Extremely large breasts are a source of considerable attention. Some women try to hide or mask their breasts with special clothing, including minimizing bras. Women with this condition may be subject to psychological problems due to unwanted attention or harassment. Depression is common in those affected.


title: Breast hypertrophy

text: In the case of a 12-year-old Japanese girl reported in 1993, her "massively enlarged" breasts caused her "intense psychological problems, incapacitating her in school activities and social relations". Actress Soleil Moon Frye, who starred as a child in the sitcom "Punky Brewster", reported in an interview with "People" magazine that boys taunted her, calling her "Hey, Punky Boobster!". It affected her professional and social life negatively. "People started to think of me as a bimbo", she said in the interview. "I couldn't sit up straight without people looking at me like I was a prostitute", Frye said.


title: Breast hypertrophy

text: Finding large bra-sizes and styles that fit is challenging. Also, larger bras are more costly, challenging to find, and unflattering to the wearer. Ill-fitting bras with narrow straps can cause chronic irritation, redness, and indentations in the shoulders. Skin rashes under the breasts are common, particularly during warm weather. Heavy breasts may cause headaches, neck pain, upper and lower back pain, and numbness or tingling in the fingers. There is a possible connection between macromastia and carpal-tunnel-syndrome.


title: Breast hypertrophy

text: Insurance companies in the United States typically require the physician to provide evidence that a woman's large breasts cause headaches or back and neck pain before they will pay for reduction mammoplasty. Insurance companies also mandate a woman who is overweight, which is often the case with gigantomastia, to first lose a certain amount of weight. They also commonly require the patient to try alternative treatments like physical therapy for a year or more.


title: Breast hypertrophy

text: One early and extreme case study of gigantomastia dates to 1670. The patient died four months after the onset of enlargement. One breast removed after the woman's death weighed 29 kg (64 lb).


title: Breast hypertrophy

text: On April 17, 1848, a 42-year-old woman named Lu-shi was treated for hypertrophy in a Chinese hospital. She was treated by a missionary physician. On December 24, 1849, the left breast, measuring 67 cm (26.5 in) in circumference, and weighing 2.7 kg (6 lb), was removed in a procedure lasting three and a half minutes. The right breast was removed one month later. It measured 61 cm (24 in) in circumference and weighed 2.5 kg (5.5 lb).


title: Breast hypertrophy

text: In 2005, a woman reported that her breasts grew at puberty from nothing to a C cup in one month. When she became pregnant for the first time, her breasts increased two cup sizes in a few days. Immediately after her first birth, her breasts grew three cup sizes. After her second child was born, her breasts increased six cup sizes. After her third childbirth, they grew 10 cup sizes, and after her fourth child was born, they grew nine cup sizes. In this instance, the swelling abated about 10 days after childbirth, but her bra cup size remained E to a G for the next year. About one year postpartum, her breasts rapidly atrophied to AA cup size.


title: Breast hypertrophy

text: One of the most severe cases of macromastia was reported from Ilorin in Nigeria. In 2007, Dr Ganiyu Adebisi Rahman and his colleagues reported the case of a 26-year-old woman who presented with massive swelling of her breasts and bilateral axillary swellings of 6 years duration. Dr Rahman led a team of surgeons in Ilorin to perform a total bilateral excision of the hypertrophied axillary breasts, and bilateral breast amputation with composite nipple-areola complex graft of the normally located breasts. The total weight of the breast tissues removed was 44.8 kilograms.


title: Breast hypertrophy

text: Another extreme case was observed in 2008 in Maria Vittoria Hospital in Turin, Italy, where the amount removed from both breasts was 17.2 kg (38 lb). The growth occurred during puberty making it a case of juvenile gigantomastia, but the patient did not seek treatment until the age of 29. Another extreme case was observed on August 28, 2003, when a 24-year-old woman was admitted to the Clinical Center Skopje in Macedonia with gigantomastia of pregnancy and the amount later removed from both breasts was 15 kg (33 lb) in total. A second case in Macedonia was reported when the breasts of a 30-year-old woman from a remote mountain village in eastern Macedonia suddenly grew to more than total.


title: Breast hypertrophy

text: As the disorder becomes more widely known, media reports have increased. French Canadian Isabelle Lanthier appeared on Montel Williams' talk show where she told how her chest grew from 86 cm (34 in) to 133 cm (52.5 in) in five months during her pregnancy. At their largest, one breast weighed 6.8 kg (15 lb) and the other 5.4 kg (12 lb). Her husband custom-made a special bra to support her breasts.


title: Breast hypertrophy

text: In 2007, a Chilean TV station covered the story of 32-year-old Yasna Galleguillos from Antofagasta, who experienced ongoing back pain, making everyday tasks very difficult to perform. She underwent breast reduction surgery to relieve her pain. Surgeons removed from one breast and from the other breast.


title: Breast hypertrophy

text: On October 29, 2009, the Philippine television network GMA News and Public Affairs, producers of "Wish Ko Lang" ("Just My Wish") hosted by Vicky Morales, profiled the story of Pilma Cabrijas, a 30-year-old woman affected by gigantomastia. The woman was told by a folk healer that her condition may have been caused by a curse. The measured bust circumference without appropriate bra support was 160 cm (63 in). The weight of her breasts was not reported in detail, but seemed to weigh "as much as two children." She had breast reduction surgery performed, but her breasts regrew. The producers of "Wish Ko Lang" paid for additional surgery.


title: Breast hypertrophy

text: In 1993, the Japanese journal "Surgery Today" reported on the case of a 12-year-old girl. Only tall and weighing , her breasts began to develop at age 11 before the onset of menstruation. Over the next eight months, both breasts grew abnormally large, and physicians treating her found that her physiological development was normal except for her breasts. The weight produced by their symmetrical and massive enlargement resulted in marked curvature of the spine. Lab tests of her blood for hormones and biochemical substances showed normal values, though tests revealed that it might have been caused by hypersensitivity to estrogen. She underwent a bilateral reduction mammoplasty. Surgeons removed of tissue from her right breast and from her left breast. She was administered tamoxifen afterward to suppress breast regrowth.


title: Breast hypertrophy

text: A more severe case of virginal breast hypertrophy of an 11-year-old girl was reported in 2008. The breasts had begun to grow rapidly at puberty and had reached the point of causing physical impairment and respiratory compromise after one year. The skin was intact without any ulcerations. Blood chemistry and endocrine investigation was normal. A bilateral reduction mammaplasty with free nipple grafts was performed. Six kg of the right breast and 6.5 kg of the left breast were removed, resulting in a removal of 12.5 kg of tissue in all (24% of the total body weight).


title: LATAM Brasil

text: LATAM Airlines Brasil, formerly TAM Linhas Aéreas, is the Brazilian brand of LATAM Airlines Group and one of the largest airlines in the country. According to the National Civil Aviation Agency of Brazil (ANAC), between January and December 2019, LATAM had 34.7% of the domestic, and 20.9% of the international market share in terms of passenger-kilometers flown, making it the second largest domestic and largest international airline in Brazil.


title: LATAM Brasil

text: Before the takeover, TAM was Brazil's and Latin America's largest airline. Its headquarters are in São Paulo, operating scheduled services to destinations within Brazil, as well as international flights to Europe and other parts of North and South America. Shares in the company were traded on the São Paulo Exchange (BM&F Bovespa) and New York Stock Exchange as "TAM". Prior to the merger with LAN, the company closed its capital, transferring its shares to LATAM Airlines Group. However, in August 2015, it was announced that the two airlines would fully rebrand as LATAM, with one livery to be applied on all aircraft by 2018. The airline withdrew from the Star Alliance, and joined Oneworld, effective 31 March 2014. The carrier left Oneworld on May 1, 2020.


title: LATAM Brasil

text: TAM – Táxi Aéreo Marília and TAM – Transportes Aéreos Regionais were two different entities, although both belonged to the TAM Group. TAM – Marília, an air taxi company founded on February 21, 1961 at the city of Marília, provided the start-up infrastructure for TAM – Regionais.


title: LATAM Brasil

text: On November 11, 1975, the Government of Brazil created the Brazilian Integrated System of Regional Air Transportation and divided the country in five different regions, for which five newly created regional airlines received a concession to operate air services. Founded by Rolim Adolfo Amaro TAM – Transportes Aéreos Regionais S/A was the third of those regional airlines to be made operational. Its services started on July 12, 1976, and its operational area comprised parts of the Southeast and Central West regions of Brazil, specifically the states of Mato Grosso do Sul, and parts of Mato Grosso, and São Paulo plus the possibility of serving the cities of Cuiabá, Rio de Janeiro, Londrina, Maringá and Brasília when linking them to its area of concession.


title: LATAM Brasil

text: TAM – Linhas Aéreas Regionais was formed as a joint-venture between TAM – Táxi Aéreo Marília and VASP, the latter of which was then a state-owned airline. The airline received the IATA code KK on October 13, 1999. The new airline flew Embraer EMB 110 Bandeirantes at first, but these proved grossly inadequate for the task at hand, and even at full capacity needed to be subsidized by the government in order to be profitable.


title: LATAM Brasil

text: TAM went on to purchase three used Fokker F27 turboprops, which were subsequently refurbished by Fokker in the Netherlands. In order to obtain the import authorization for the aircraft, a deal was struck with the government in which TAM was forced to maintain 3 Bandeirantes for every F27, as well as removing 5 seats from each one, bringing the F27's capacity down to 40 passengers. A fourth F27, previously owned by Air New Zealand, was added to the TAM fleet in 1981. By 1983, TAM had acquired 10 F27s. By 1981, TAM had flown one million passengers, and two million by 1984.


title: LATAM Brasil

text: In August 1986, the company, under financial stress, went public and began floating stock in the market. The same year, TAM – Transportes Aéreos Regionais (KK) acquired another regional airline, VOTEC, which operated in areas of northern and central Brazil. VOTEC was then renamed Brasil Central Linhas Aéreas. TAM and Brasil Central were both regional airlines and operated in different designated areas. They, however, operated as a consortium with integrated networks and fleet, with the most notable differences being the flight number IATA codes (whereas TAM had the IATA code KK, Brasil Central operated with the code JJ inherited from VOTEC), the different color schemes of the aircraft, and their designated areas of operation. In 1988, TAM flew its 3 millionth passenger.


title: LATAM Brasil

text: On May 15, 1990, the Brazilian Government lifted restrictions on operational areas of regional airlines allowing them to fly anywhere in Brazil. As a consequence, Brasil Central was renamed "TAM - Transportes Aéreos Meridionais", acquired the same color scheme of TAM (KK) but maintained the IATA code JJ.


title: LATAM Brasil

text: In 2000 TAM (KK) was merged into TAM (JJ) and TAM (JJ) was renamed TAM Transportes Aéreos. The code JJ was maintained and the code KK was released back to IATA.


title: LATAM Brasil

text: Despite TAM's success in the market, it was evident the airline would not last long when competing against airlines such as Varig and VASP, both of which already possessed Boeing 737s in their fleet. Amaro then tried to buy VASP, which was about to be privatized and called the project "Revolution". Having lost the bid, he opted for slower growth with the gradual addition of new aircraft, re-dubbed "Evolution".


title: LATAM Brasil

text: On September 15, 1989, TAM arranged for the acquisition of two Fokker 100 jets. Like the F27s before them, TAM did not actually purchase these aircraft but used Amaro's credibility to arrange for a third-party asset management company, Guinness Peat Aviation to purchase them and subsequently lease them back to TAM. Two more were added in 1991. In 1992, TAM carried its eight millionth passenger. By 1993, through the use of the Fokker 100 fleet, which now numbered at 14, TAM was serving 56 cities in Brazil.


title: LATAM Brasil

text: In 1996 TAM bought another airline, Helisul Linhas Aéreas, which used the trade name of TAM. In 1997, TAM ordered its first large jets; the airline ordered 45 planes from Airbus, including 10 A330s, 4 A319s, and 34 A320s. In 1997, the Airbuses began to be delivered and the airline flew its first international service, from São Paulo to Miami International Airport. In 1998 TAM purchased the passenger division of Itapemirim Transportes Aéreos.


title: LATAM Brasil

text: Two years later, in 1999, services to Europe were inaugurated through a code share service with Air France, to Paris-Charles de Gaulle Airport. In 2000, the airline was renamed TAM Linhas Aéreas. Long running discussions to merge with Varig ended in 2004. In 2008, TAM transported 30,144,000 passengers, with an average load factor of 71%. As of 2010, the airline is owned by the Amaro family (46.25%), Amaro Aviation Part (3.52%), treasury stocks (0.27%) and minority shareholders (49.96%). It employs 24,000 staff. On May 13, 2010, TAM became the 27th member of Star Alliance. David Barioni served as the airline's president from 2007 to 2009.


title: LATAM Brasil

text: In 2009 TAM decided to replace its Passenger Service System provided by Sabre, known as Sabresonic, with the Altéa platform from Amadeus. The migration to Altéa was completed in the first quarter of 2010.


title: LATAM Brasil

text: On March 30, 2011, TAM signed a letter of intentions to purchase up to 31% of the shares of TRIP Linhas Aéreas, a regional airline which code-shares with TAM since 2004. A final decision had however been postponed, and finally in February 2012 the purchase agreement was not renewed. On May 28, 2012, TRIP was sold to Azul Brazilian Airlines. Code-sharing operations ended on March 28, 2013.


title: LATAM Brasil

text: On December 21, 2009, TAM Linhas Aéreas purchased Pantanal Linhas Aéreas. At that time TAM decided to maintain Pantanal as a separate airline within the TAM Group integrated into the network of TAM. Starting August 1, 2011 Pantanal operated flights on behalf of TAM, all with origin and destination at São-Paulo-Congonhas Airport. On March 26, 2013, Brazilian authorities approved the incorporation of all Pantanal assets by TAM and Pantanal ceased to exist. The incorporation process was completed on August 23, 2013.


title: LATAM Brasil

text: In January 2013, the Jet Airliner Crash Data Evaluation Centre (JACDEC) determined that TAM Linhas Aéreas had the second-worst safety record in the world. The ratings take into account the number and deadliness of the hull losses (destroyed airplanes) they have suffered in the past 30 years, how they have fared more recently, and how many flights they have flown without incident. The results do not take into account the cause of the hull losses, or whether the airline is at fault, so they are not a perfect measure of how safely an airline behaves.


title: LATAM Brasil

text: On August 13, 2010, TAM signed a non-binding agreement with Chilean airline LAN Airlines to merge and create LATAM Airlines Group. This was changed into a binding agreement on January 19, 2011. LATAM's agreement was approved with 11 restrictions by Chilean authorities on September 21, 2011. These included transferring 4 slots at São Paulo-Guarulhos to competitors interested in operating flights to Santiago de Chile, renouncing membership to either Oneworld or Star Alliance, restricting increase capacity on flights between Brazil and Chile, and opening code-share possibilities and fidelity program membership to interested competitors. On December 14, 2011, Brazilian authorities approved the agreement imposing similar restrictions as Chilean authorities. By August 2012 LATAM made a decision in favor of Oneworld and frequencies between São Paulo and Santiago de Chile were reduced: TAM had two pairs of slots while LAN had four. LAN ceded two pairs to competitors interested in using them which later was known to be Sky Airline. The merger was completed on June 22, 2012. As of May 5, 2016 TAM adopted the name LATAM. It still continues to use the "TAM" name as a call sign for its LATAM Brasil operated flights.


title: LATAM Brasil

text: On July 9, 2020, LATAM Brasil announced that it filed for judicial reorganization in the United States due to the impacts of the COVID-19 crisis on the company's operations. The LATAM Airlines group and its affiliates had already entered the debt restructuring process in May of the same year under the protection of Chapter 11 of the United States bankruptcy law, which allows a deadline for companies to reorganize themselves financially. Despite the announcement, the company continues to operate normally.


title: LATAM Brasil

text: In 1994 TAM Linhas Aéreas established a small subsidiary airline in Paraguay called Aerolíneas Paraguayas with a fleet consisting mostly of the Cessna 208 Caravans, formerly operated by TAM. On September 1, 1996, TAM via ARPA, purchased 80% of the shares of the former state-owned Líneas Aéreas Paraguayas and merged it with ARPA. The new airline was named "TAM - Transportes Aéreos del Mercosur" and maintained the IATA code of LAP, PZ. Today TAM owns 94.98% and the Paraguayan government 5.02% of the shares.


title: LATAM Brasil

text: In 2008, following a branding strategy, the name TAM Mercosur was dropped and the airline adopted an identical corporate identity of TAM Airlines. However, its corporate structure remained the same. This airline is today informally known as TAM Paraguay, and uses the IATA code PZ. In 2016, the airline was rebranded to LATAM Paraguay, at the same time as all other airlines of the LATAM group.


title: LATAM Brasil

text: The network of LATAM Brasil and LATAM Paraguay covers Brazil, Paraguay, Europe, North and South America.


title: LATAM Brasil

text: On June 16, 2005, TAM purchased 20 additional Airbus A320 family aircraft (including the A319, A320 and A321), with an additional 20 options. These were expected to be delivered between late 2007 and 2010, adding to the already scheduled delivery of 6 A320s between 2006 and 2008. At the same time, the company signed a memorandum of understanding with Airbus stating its intent to buy 10 of the new Airbus A350-900 plus 5 options, with deliveries planned due to commence at the end of 2014. However, LATAM received its first A350 in early 2016.


title: LATAM Brasil

text: TAM has also signed a firm contract with Airbus to acquire 37 additional aircraft. The order comprises twelve A319s, 16 A320s, three A321s and three A330s and includes twelve unspecified extra options. This would bring the number of aircraft in TAM's fleet acquired directly from Airbus to 115 aircraft. The commitments are separate from deals in earlier years for 29 firm-ordered A320s and 20 options. The deliveries were concluded by 2010. In 2013, TAM announced that it would phased out 3 of the oldest Boeing 767 it operates; however, it later changed plans and decided to keep the aircraft, adding some more aircraft from LAN Airlines instead. They replaced the A330-200s. TAM also received the first aircraft of the A320 family with Sharklets in April 2013.


title: LATAM Brasil

text: LATAM Pass is the frequent flyer program of LATAM Brasil. Program points can be redeemed for tickets on airlines of the LATAM group and selected partners. It is divided into the following categories and percentages of mileage accrual:


title: Silver Streak (film)

text: Silver Streak is a 1976 American buddy comedy thriller film about a murder on a Los Angeles-to-Chicago train journey. It was directed by Arthur Hiller and stars Gene Wilder, Jill Clayburgh, and Richard Pryor, with Patrick McGoohan, Ned Beatty, Clifton James, Ray Walston, Scatman Crothers, and Richard Kiel in supporting roles. The film score is by Henry Mancini. This film marked the first pairing of Wilder and Pryor, who were later paired in three more films.


title: Silver Streak (film)

text: Book editor George Caldwell, en route to a wedding aboard the Silver Streak, meets salesman Bob Sweet and Hilly Burns, secretary to Rembrandt historian Professor Schreiner. While sharing nightcaps in Hilly's sleeper car, George sees Schreiner's body fall from the train outside her window. Investigating Schreiner's train compartment, George encounters Johnson, Whiney, and Reace, toughs who have ransacked Schreiner's belongings. Reace throws George off the train. After walking along the tracks, George meets a farmer and they overtake the train in her biplane.


title: Silver Streak (film)

text: George sees Hilly with art dealer Roger Devereau and his employees Johnson (impersonating Schreiner), and Whiney. Devereau apologizes to George for the misunderstanding involving Reace, also under his employ. Sweet reveals himself to be an undercover FBI agent named Stevens. The bureau has been investigating Devereau, a criminal who passes himself off as an art expert. Devereau's plan is to discredit Schreiner's book, which would expose Devereau for authenticating forgeries as original Rembrandts. Inside Schreiner's book, George finds letters written by Rembrandt that would prove Devereau's guilt. Reace kills Stevens, thinking he is George. A fight ends on the roof of the train, where George shoots Reace before being knocked off by a train signal.


title: Silver Streak (film)

text: On foot again, George finds the local sheriff who has trouble making sense of his story. The sheriff says the police are after George for killing Stevens. George escapes, stealing a patrol car that had been transporting car thief Grover T. Muldoon. George and Grover work together to catch up to the train at Kansas City, so George can save Hilly from Devereau's crew. Grover disguises George as a black man so George can get by police to board the train.


title: Silver Streak (film)

text: George is captured, but he and Hilly are rescued from Devereau's room by Grover, disguised as a steward. After a shootout, George and Grover jump off the train and are arrested. They meet federal agent Donaldson, former partner to Stevens, who tells George and Grover the police knew all along George didn't kill Stevens - they were only trying to protect George from Devereau. Donaldson made up the news story about Stevens' murder. After George explains Devereau's plan, Donaldson has the train stopped. Devereau burns the Rembrandt letters.


title: Silver Streak (film)

text: George boards with Grover as Devereau climbs onto the locomotive and shoots the fireman. Whiney is wounded by Donaldson and kicked off the train by Devereau. George shoots Johnson and Devereau shoots the engineer, placing a toolbox on the switch to keep the engine running. Devereau is disabled by shots from George and Donaldson, and is decapitated by an oncoming freight train.


title: Silver Streak (film)

text: With the help of a porter, George uncouples the runaway engine from the passenger cars. The engine roars into Chicago's Central Station, destroying everything in its path. The passenger cars follow, gliding safely into the station. Grover steals a Fiat X1/9 and drives away. George and Hilly leave together.


title: Silver Streak (film)

text: The film was based on an original screenplay by Colin Higgins, who at the time was best known for writing "Harold and Maude". He wrote "Silver Streak" "because I had always wanted to get on a train and meet some blonde. It never happened, so I wrote a script."


title: Silver Streak (film)

text: Higgins wrote "Silver Streak" for the producers of "The Devil's Daughter", a TV film he had written. Both they and Higgins wanted to get into television. The script was sent out to auction. It was set on an Amtrak train and Paramount was interested, but wanted Amtrak to give its approval. Alan Ladd Jr. and Frank Yablans at 20th Century Fox didn't want to wait and bought the script for a then-record $400,000. Ladd said "It was like the old Laurel and Hardy comedies. The hero is Laurel, he falls off the train, stumbles about, makes a fool of himself, but still gets the pretty girl. Audiences have identified with that since Buster Keaton."


title: Silver Streak (film)

text: Colin Higgins wanted George Segal for the hero – the character's name is George – but Fox preferred Gene Wilder. Ladd reasoned that Wilder was "younger, more identifiable for the younger audience. And he's so average, so ordinary, and he gets caught up in all these crazy adventures." (Wilder was actually older than Segal.)


title: Silver Streak (film)

text: Colin Higgins claimed the producers did not want Richard Pryor cast because Pryor had recently walked off "The Bingo Long Traveling All-Stars & Motor Kings"; he says the producer at one stage considered casting another black actor as a backup. However, Pryor was very professional during the shoot.


title: Silver Streak (film)

text: The film had over 400 previews around the United States starting November 28, 1976 in New York City. It had its premiere at Tower East Theater in New York on Tuesday, December 7, 1976 and opened in New York City the following day. It opened in Los Angeles on Friday, December 10 before opening nationwide in an additional 350 theaters on December 22.


title: Silver Streak (film)

text: The film grossed over $51 million at the box office and was praised by critics, including Roger Ebert. It maintains an 81% approval rating at Rotten Tomatoes from 21 reviews. Ruth Batchelor of the Los Angeles Free Press described it as a "fabulous, funny, suspenseful, wonderful, marvelous, sexy, fantastic trip on a train, with the most lovable group of characters ever assembled." Gene Siskel of the "Chicago Tribune", however, called the film "a needlessly convoluted mystery yarn, which calls everyone's identity into question except Wilder's." Siskel, who gave the film just two stars, added that "the story isn't easy to follow" and that "I'm still not sure whether Clayburgh's character, secretary to Devereaux, was in on the hustle from the beginning." (Hilly Burns was actually Professor Schreiner's secretary, not Devereaux's.)


title: Silver Streak (film)

text: Though the film dates to 1976, Henry Mancini's score was never officially released on a soundtrack album. Intrada Records' 2002 compilation became one of the year's best-selling special releases.


title: Söğüt

text: Söğüt (, ; Greek: Θηβάσιον or Θηβάσιο, "Thêbásion") is a town and district in Bilecik Province, Turkey. It is in the Marmara region in the north-west of the country, with an area of , bordering Bilecik to the west, Gölpazarı to the north, İnhisar to the north-east, Tepebaşı (Eskişehir) to the south-east, and Bozüyük to the south-west. Söğüt district has 5 boroughs and 23 villages, with the population last recorded as 21,012 citizens (2000), but according to a 2010 estimate the population was 19,425.


title: Söğüt

text: The name of the settlement is first attested under the Greek name "Thêbásion" in 13th century. According to Ottoman cadastral record books of 1487 in Hüdavendigâr area the town was registered under the Turkish name "Beğsöğüdü" or "Bey Söğüdü", and this name took the form "Söğüd" in government records after the first half of the 17th century. According to Sevan Nişanyan during the 15th and 16th centuries "Söğüd" was used the describe the "kazâ", meanwhile "Beğsöğüdü" was used to mean the central settlement of that "kazâ". He also proposed that the Greek name, if loaned to Turkish, must have been evolved to "Sivad" or "Sivas", which in turn might be the source of the later Turkish names.


title: Söğüt

text: Söğüt was a Seljuk Turkish land in western Anatolia, bordering the Eastern Roman Empire. It was given to Ertuğrul by the Seljuk Sultan Alaeddin Kayqubad I. Ertuğrul bey and his tribe (allegedly part of the Kayi tribe/branch of the Oghuz Turks who settled Anatolia in the 12th and 13th centuries) migrated and settled there during the Mongol invasion after the Battle of Köse Dağ. Ertuğrul ruled there and handled the matters of the people living in there until his death. He also made a mosque for the Muslims living there and dug up a well in there so that they could use for Ablution. The mosque is still located in there as Ertuğrul Gazi Mosque. As the Rum Seljuk state collapsed, Söğüt became the centre of the Beylik of the Osmanoğulları or Osmanlı Beylik (which later expanded to become the Ottoman Empire). Legend has it that the "bey" (chief) of the tribe in the late 13th century, Ertuğrul, bravely kept the enemies at bay so that his son, Osman, could conquer them all during his reign from 1299 to 1326. When Osman's son, Orhan, came to power after his father's death, he renamed the Kayi tribe Osmanlı in honour of his father. The village of Söğüt (Byzantine Thebasion until 1231) later grew into a town that served the Osmanlı Beylik as its capital until the capture of the Byzantine city of Proussa (Bursa) in 1326 that succeeded it as the administrative centre of the Beylik.


title: Söğüt

text: Söğüt was the birthplace of Sultan Osman I. It was conquered by Ertuğrul for the Anatolian Seljuks from the Nicean Empire in 1231. It had a kaza centre in the Ertuğrul Sanjak of Hüdavendigâr Vilayet, the centre of which was Bilecik. The kaza centre included present-day districts of İnhisar, İnönü, Mihalgazi, Sarıcakaya and Yenipazar, central and eastern parts of Bozüyük and some villages of Nallıhan and Tepebaşı before World War I.


title: Söğüt

text: Söğüt was occupied three times by the Greek Army during the Turkish War of Independence: 8–11 January 1921, 24 March-21 April 1921 and 12 July 1921 – 6 September 1922.


title: Söğüt

text: Today Söğüt is a small town in the humid river valley of Bilecik Province in Turkey. Turkish history and life-size statues of the Ottoman sultans are exhibited in the Söğüt Ethnographical Museum. It is also the 3rd biggest district center in its province after Bozüyük and Bilecik.


title: Jaguar XF (X250)

text: The Jaguar XF (X250) is an executive luxury sports sedan car that was manufactured and marketed by the British automobile manufacturer Jaguar Cars. The XF was available as a four-door saloon and a five-door estate marketed as the Sportbrake. Launched Autumn 2007 as a replacement for the S-Type, the XF was designated internally as the "X250". The X250 was succeeded by the X260 in 2015. X250 was the first of the new styled Jaguars.


title: Jaguar XF (X250)

text: The XF was developed at Jaguar's Whitley design and development HQ in Whitley, Coventry and was built at Castle Bromwich Assembly facility in Birmingham.


title: Jaguar XF (X250)

text: Initially, the XF was planned to use an all aluminium platform but due to time constraints put by Jaguar's board on the development team, the X250 makes use of a heavily modified Ford DEW98 platform.


title: Jaguar XF (X250)

text: The XF was launched at the 2007 Frankfurt Motor Show, following the public showing of the C-XF concept in January 2007 at the North American International Auto Show. Customer deliveries commenced in March 2008, with a range of V6 and V8 engines.


title: Jaguar XF (X250)

text: Designed by Jaguar's design director Ian Callum, the styling incorporates an oval mesh grille recalling the original XJ of 1968. The boot lid retained the S-Type's chromed blade to its edge and included a "leaper" hood ornament.


title: Jaguar XF (X250)

text: The XF was launched with a variety of trims called, depending on country, 'SE' (or 'Sport'), 'Luxury', 'Premium Luxury' (or 'Premium'), 'Portfolio' (or 'Premium Portfolio'), 'SV8' (or 'Supercharged') and 'R'. For the UK market, company car-friendly 'Executive Edition' and 'SE Business' models with a lower tuned versions of the 3.0 L and 2.2 L diesel engines respectively were available.


title: Jaguar XF (X250)

text: The interior included air conditioning vents which are flush-fitting in the dash, rotating open once the engine is started, and a rotating gearshift dial, marketed as JaguarDrive Selector, which automatically elevates from the centre console. Another departure from the traditional Jaguar cabin ambiance is the use of pale-blue backlighting to the instruments, switchgear, and around major control panels. Some minor systems, such as the interior lighting, are controlled by touching the light covers. The glove compartment also opens to the touch. The XF has no cloth interior option, with all trim levels featuring leathers. Wood veneers are available along with aluminium, carbon fibre and piano black lacquer trims.


title: Jaguar XF (X250)

text: The XFR was announced at Detroit's North American International Auto Show in January 2009 as a new performance derivative of the XF range, and featured the new 5.0-litre supercharged AJ-V8 Gen III engine rated at , a revised front bumper and spoiler and alloy wheels.


title: Jaguar XF (X250)

text: In April 2011, Jaguar revealed the details of a facelift for the XF at the New York International Auto Show, with manufacturing beginning in July 2011.


title: Jaguar XF (X250)

text: The facelift includes front and rear styling changes which are based on the original Jaguar C-XF concept car, internal trim enhancements, adaptive cruise control, and a new four-cylinder 2.2-litre diesel engine, which is combined with a new eight-speed automatic transmission and stop-start technology to emit 149 g/km CO and fuel consumption of .


title: Jaguar XF (X250)

text: The Sportbrake was officially introduced in March 2012, and went on-sale in October of the same year.


title: Jaguar XF (X250)

text: It is available with all of the saloon's engines and has a loading capacity of with the seats up and with them folded.


title: Jaguar XF (X250)

text: The maximum capacity surpasses that of the contemporary BMW 5 Series Touring, Cadillac CTS Sport Wagon, and the Mercedes-Benz CLS-Class (X218) Shooting Brake.


title: Jaguar XF (X250)

text: The extended roofline increases rear headroom by and the rear bench includes a 60:40 split and remote-controlled 'one-touch' folding function. The load area is fitted with multi-function rails and is long and wide.


title: Jaguar XF (X250)

text: An R-S version of the XF was confirmed in 2012 following an image released shortly before the Los Angeles Auto Show. It uses the same 5.0-litre supercharged V8 engine as the Jaguar XKR-S.


title: Jaguar XF (X250)

text: The engine is rated at at 6,500 rpm and of torque at 5,500 rpm. The XFR-S has a 0– time of 4.4 seconds and a top speed of . The XFR-S differs from the XFR as it has bespoke 20-inch alloy wheels, wider front grills and carbon fibre. The front grills aid aerodynamic efficiency as does the large rear wing and rear diffuser.


title: Jaguar XF (X250)

text: The XF's body was developed using computational fluid dynamics (CFD) before wind tunnel testing. Every area from the outer skin to the lightweight, composite undertray to the cooling airflow (even the shape of the exterior mirrors) was optimised using this process. The higher, squarer tail is more efficient aerodynamically than a lower, rounded one, and the XF's coupé-like roofline and raised bootlid lip improve airflow over the rear of the car.


title: Jaguar XF (X250)

text: The basic substructure of the XF has been carried over from the preceding S-Type, although the body has been stretched to meet crash safety requirements, and heightened to provide additional headroom while still retaining the "saloon within a coupé" proportions. The suspension and mountings are the same as that used on the XK, while the engine line-up is basically similar to that used in the S-Type.


title: Jaguar XF (X250)

text: Sound and vibration insulation is provided by the addition of a special underbody tray and engine mounts, a tuned exhaust system, and a double bulkhead between the engine bay and passenger compartment.


title: Jaguar XF (X250)

text: All XF models are automatic and are Euro 5 compliant. The naturally-aspirated petrol 3.0-litre V6 was discontinued in Europe in 2010, but continued to be sold elsewhere for the X250's production lifespan.


title: Jaguar XF (X250)

text: Next Green Car (NGC) an organisation that analyses vehicle emissions and rates them from 0 (cleanest) to 100 (dirtiest) – analysed the emissions from X250 XF's range: ADAC's EcoTest has also rated three of the diesel engines.


title: Jaguar XF (X250)

text: In 2008 the 4.2-litre supercharged V8 engine was replaced by the new 5.0-litre supercharged V8 engine rated at , and came with Adaptive Dynamics (computer controlled continuously variable damping) and Active Differential Control (electronically controlled rear differential).


title: Jaguar XF (X250)

text: The 2.7-litre V6 diesel engine was replaced in 2009 with a new 3.0-litre V6 diesel engine. The engine is the same as the 3.0-litre TDV6 used in the Land Rover Discovery 4 with the newly used ZF 8 speed automatic transmission. The AJ-V6D Gen III, came in two states of tune. The diesel engines are a product of the joint venture between Ford and Peugeot-Citroën.


title: Jaguar XF (X250)

text: The XF was launched with only an automatic gearbox, and all models initially used the six-speed ZF 6HP26 automatic transmission. For model years 2010–2012, some engines (the 3.0 L diesel and 5.0 L supercharged petrol) used the second generation six-speed ZF 6HP28 transmission. During 2012–2013, 8-speed ZF 8HP70 transmissions replaced the 6-speed transmissions for all engines. The gears can either be selected using a rotary dial that rises from the centre console on start-up or can be manually controlled using paddles behind the steering wheel. AWD is available in both RHD and LHD markets with variances according to consumer demand for engine types. Entry level 2.0-litre diesel models are available in AWD in UK RHD, however petrol AWD models are not available in that market.


title: Jaguar XF (X250)

text: The standard audio system comprises a ten-speaker, 250 W set-up that includes a radio, CD player, WMA and MP3 compatibility as well as USB storage devices.


title: Jaguar XF (X250)

text: From 2008 to 2012, there was an optional Bowers & Wilkins (B&W) sound system available. At its core there are 14 speakers which (with the exception of the aluminium high-frequency tweeters) employ B&W's Kevlar composite speaker cones. Each front door contains a woofer, a mid-range speaker and a dome tweeter (the latter two wired in parallel with a crossover), while each rear door houses a similar woofer and tweeter. As a centre speaker there is a full-range driver, similar to the two full-range 'surround' speakers located on the rear parcel shelf. The B&W system has been reviewed by journalists at "Autocar" magazine, who proclaimed it the best in-car system they have ever heard.


title: Jaguar XF (X250)

text: For 2013 models, Jaguar introduced the option of a new Meridian sound system upgrade instead of B&W; with a choice of 380 W 11-speaker or an 825 W surround sound 17-speaker system.


title: Jaguar XF (X250)

text: A 7-inch full-colour screen is fitted to the dashboard of all XFs and can be used to control most multimedia systems. The same screen can also be upgraded with analogue and digital television capability. Available as an option is JaguarVoice which allows the driver to speak commands to control everything from the sound and navigation systems to telephone calls and the climate control system.


title: Jaguar XF (X250)

text: The XF was crash tested in 2010 by Euro NCAP and it gained a four star rating. The XF's result was seen as a disappointment by some car magazines. When retested in 2011, the XF showed improved scores in adult occupant, child occupant and pedestrian areas.


title: Jaguar XF (X250)

text: The Australasian New Car Assessment Program (ANCAP) also tested the XF and gave it a score of 32.38 points out of 37, giving it an ANCAP rating of 4 out of 5.


title: Jaguar XF (X250)

text: Thatcham's New Car Whiplash Ratings awarded the XF 'good' score for Geometric, Dynamic and Overall ratings.


title: Jaguar XF (X250)

text: Deadlocks, an alarm and an engine immobiliser are fitted as standard to the XF. The car also locks itself when it reaches a pre-set speed to help protect against carjackings. The XF was tested by Thatcham's New Vehicle Security Ratings (NVSR) organisation and achieved the following ratings:


title: Jaguar XF (X250)

text: On 7 November 2008, a modified XFR was driven by Paul Gentilozzi of Rocketsports, who propelled the car to a new Jaguar record of on the Bonneville Salt Flats. The new record beat the previous Jaguar record of in an XJ220 in 1992. Changes to the stock vehicle included low-mounted rear spoiler, increased power to by a remapped ECU, a modified air intake and exhaust system and revised supercharger settings.


title: Jaguar XF (X250)

text: A special version of the XF Diesel S was announced in 2009 for the UK police car market, with the first police force orders in 2010.


title: Jaguar XF (X250)

text: Its emergency vehicle equipment included a roof-mounted light bar with 3,600 light elements, side alley lights, blue and white strobing LEDs in the grille and blue flashing LEDs along the side of the car, blue and red flashing LED lights in the rear light clusters.


title: Make It Big

text: Make It Big is the second and final studio album from British pop duo Wham!, released in 1984. In comparison to their earlier work, Wham! (George Michael and Andrew Ridgeley) had more control over the album's production and Michael would also be credited as a producer. The album was a commercial success, hitting number one in both the US and the UK and spawning four singles, all reaching the top five in the US and the UK.


title: Make It Big

text: The music video for single "Wake Me Up Before You Go-Go" had the duo in shirts that read "Choose Life". It would be the first of several hits from the album. The second single "Careless Whisper" is technically a Wham! song as it appears on the Wham! album "Make It Big". However, when released as a single, it was credited either to "Wham! featuring George Michael" (in North America and several other countries) or solely to "George Michael" (in the United Kingdom and some European countries) as it became apparent, that at some point in the near future, Michael would be embarking on a solo career. The music video for third single "Freedom" featured the duo while performing a concert in China; incidentally Wham! would become the first Western popular music act to tour China. The fourth single "Everything She Wants" was released as a double A-side with "Last Christmas"; "Last Christmas" would later appear on "Music from the Edge of Heaven", an album released only in North America and Japan.


title: Make It Big

text: "Make It Big" was certified 4× platinum in the US during the time of its release, and has since been certified 6× platinum in the US.


title: Make It Big

text: The album was mostly written and recorded at Studio Miraval in Southern France over a course of six weeks, beginning in early July 1984. This allowed Michael to escape press attention and work peacefully. According to Andrew Ridgeley, the decision to record in the south of France was made largely due to tax reasons, as well as it being the ideal place for them to spend the summer due to the hot weather. Plus, it was 1 and a half hour away from London, and Michael "had to keep going back to do things for Careless Whisper". Like "Careless Whisper" and "Wake Me Up Before You Go-Go", most of the songs were recorded with a live rhythm section.


title: Make It Big

text: The main album credits attribute it as having been mixed at Good Earth Studios in London and Marcadet Studios in Paris. However, it turns out to be neither, as engineer Porter revealed: most of the album was mixed at Sarm West's Studio 2 (where "Careless Whisper" and "Wake Me Up Before You Go Go" were recorded), with some mixing already completed at Studio Miraval.


title: Make It Big

text: "Make It Big", Wham's second album, would see the duo score hit singles in the United States. Their first album "Fantastic" was a hit in the UK but failed to make an impact in the US. "Make it Big" received some positive reviews. Christopher Connelly from "Rolling Stone" wrote that the "music is an unabashed rehash of Motown", adding ""Make It Big" is an almost flawless pop record, a record that does exactly what it wants to and has a great deal of fun doing it." In a retrospective review Stephen Thomas Erlewine from AllMusic writes, "They succeeded on a grander scale than they ever could have imagined, conquering the world and elsewhere with this effervescent set of giddy new wave pop-soul."


title: Make It Big

text: Wham! embarked on a world tour to promote the album in December 1984, opening at Whitley Bay's Ice Rink, before going on to dates in Japan, Australia, United States, United Kingdom, Hong Kong and China, ending in April 1985 at the Sun Yat-sen Memorial Hall in Canton.


title: Lennard-Jones potential

text: The Lennard-Jones potential (also termed the LJ potential or 12-6 potential) is an intermolecular pair potential. Out of all the intermolecular potentials, the Lennard-Jones potential is probably the one that has been the most extensively studied. It is considered an archetype model for simple yet realistic intermolecular interactions.


title: Lennard-Jones potential

text: The Lennard-Jones potential models soft repulsive and attractive (van der Waals) interactions. Hence, the Lennard-Jones potential describes electronically neutral atoms or molecules. It is named after John Lennard-Jones. The commonly used expression for the Lennard-Jones potential is


title: Lennard-Jones potential

text: where formula_2 is the distance between two interacting particles, formula_3 is the depth of the potential well (usually referred to as 'dispersion energy'), and formula_4 is the distance at which the particle-particle potential energy formula_5 is zero (often referred to as 'size of the particle'). The Lennard-Jones potential has its minimum at a distance of formula_6, where the potential energy has the value formula_7.


title: Lennard-Jones potential

text: The Lennard-Jones potential is a simplified model that yet describes the essential features of interactions between simple atoms and molecules: Two interacting particles repel each other at very close distance, attract each other at moderate distance, and do not interact at infinite distance, as shown in Figure 1. The Lennard-Jones potential is a pair potential, i.e. no three- or multi-body interactions are covered by the potential.


title: Lennard-Jones potential

text: Statistical mechanics and computer simulations can be used to study the Lennard-Jones potential and to obtain thermophysical properties of the 'Lennard-Jones substance'. The Lennard-Jones substance is often referred to as 'Lennard-Jonesium' suggesting that it is viewed as a (fictive) chemical element. Moreover, its energy and length parameters can be adjusted to fit many different real substances. Both the Lennard-Jones potential and, accordingly, the Lennard-Jones substance are simplified yet realistic models, such as they accurately capture essential physical principles like the presence of a critical and a triple point, condensation and freezing. Due in part to its mathematical simplicity, the Lennard-Jones potential has been extensively used in studies on matter since the early days of computer simulation. The Lennard-Jones potential is probably still the most frequently studied model potential.


title: Lennard-Jones potential

text: The Lennard-Jones potential is usually the standard choice for the development of theories for matter (especially soft-matter) as well as for the development and testing of computational methods and algorithms. Upon adjusting the model parameters formula_3 and formula_4 to real substance properties, the Lennard-Jones potential can be used to describe simple substance (like noble gases) with good accuracy. Furthermore, the Lennard-Jones potential is often used as a building block in molecular models (a.k.a. force fields) for more complex substances.


title: Lennard-Jones potential

text: The Lennard-Jones potential models the two most important and fundamental molecular interactions: The repulsive term (formula_10 term) describes the Pauli repulsion at short distances of the interacting particles due to overlapping electron orbitals and the attractive term (formula_11 term) describes attraction at long ranged interactions (London dispersion force), which vanish at infinite distance between two particles. The steep repulsive interactions at short distances yield the low compressibility of the solid and liquid phase; the attractive dispersive interactions act stabilizing for the condensed phase, especially the vapor–liquid equilibrium.


title: Lennard-Jones potential

text: The functional form of the attractive term, the exponent '6', has a physical justification, which does not hold as rigorously for the repulsive term with the exponent '12'. The attractive dispersive interactions between simple atoms and molecules are a result of fluctuating partial charges. It has been shown by quantum-chemical calculations that this dispersive contribution has to decay with formula_12.


title: Lennard-Jones potential

text: The formula_10 term is mainly used because it can be implemented computationally very efficiently as the square of formula_11, which does not hold to the same extent for values other than '12'. Also, formula_10 approximates the Pauli repulsion reasonably well. If needed, the Lennard-Jones potential can be generalized using arbitrary exponents instead of 12 and 6; the resulting model is called the Mie potential. The present article exclusively discusses the original (12-6) Lennard-Jones potential.


title: Lennard-Jones potential

text: The Lennard-Jones potential exhibits a pole at formula_16, i.e. the potential energy diverges to formula_17, which can cause instabilities in molecular simulations, e.g. for the sampling of the chemical potential. The Lennard-Jones potential converges to formula_18 for formula_19. Hence, from a mathematical standpoint, attractive interactions stay present for infinitely distanced particles. These dispersive 'long-range' interactions have an important influence on several properties of the Lennard-Jones substance, e.g. the pressure or heat capacity in the vicinity of the critical point and the critical point itself. The importance of the long-range interactions were noticed already in the early stages of statistical mechanics. For computer simulations, only finite numbers of particles can be used, which leads to the fact that the potential can only be evaluated up to a finite radius formula_2, which is a so-called finite size effect. There are well-established methods to implicitly consider the thereby neglected long-range contribution for a given observable (details are given below).


title: Lennard-Jones potential

text: It is often claimed that multiple Lennard-Jones potentials and corresponding substances exist depending on the handling of the long-range interactions. This is misleading. There is only one 'Lennard-Jones potential', which is exactly defined by Eq. (1). The Lennard-Jones potential requires the consideration and evaluation of long-range interactions up to very long (actually infinite) distances – at least so that the influence of the truncation has no influence on the observable of interest for the reported decimal places.


title: Lennard-Jones potential

text: The Lennard-Jones potential implies that the particles are point masses with a mass formula_21. Even though the parameter formula_4 is often referred to as 'size of the particle', particles interacting with the Lennard-Jones potential have no uniquely defined 'size' – opposite to the hard sphere potential. Particles interacting with the Lennard-Jones potential rather have soft repulsive cores.


title: Lennard-Jones potential

text: The Lennard-Jones model describes the potential intermolecular energy formula_5 between two particles based on the outlined principles. Following Newton's mechanics, the actual force formula_24 between two interacting particles is simply obtained by negating and differentiating the Lennard-Jones potential with respect to formula_2, i.e. formula_26. Depending on the distance between the two particles, the net force can be either attractive or repulsive.


title: Lennard-Jones potential

text: The Lennard-Jones potential yields a good approximation of intermolecular interactions for many applications: The macroscopic properties computed using the Lennard-Jones potential are in good agreement with experimental data for simple substances like argon on one side and the potential function formula_27 is in fair agreement with results from quantum chemistry on the other side. The Lennard-Jones potential gives a good description of molecular interactions in fluid phases, whereas molecular interactions in solid phases are only roughly well described. This is mainly due to the fact that multi-body interactions play a significant role in solid phases, which are not comprised in the Lennard-Jones potential. Therefore, the Lennard-Jones potential is extensively used in soft-matter physics and associated fields, whereas it is less frequently used in solid-state physics. Due to its simplicity, the Lennard-Jones potential is often used to describe the properties of gases and simple fluids and to model dispersive and repulsive interactions in molecular models. It is especially accurate for noble gas atoms and methane. It is furthermore a good approximation for molecular interactions at long and short distances for neutral atoms and molecules. Therefore, the Lennard-Jones potential is very often used as a building block of molecular models of complex molecules, e.g. alkanes or water. The Lennard-Jones potential can also be used to model the adsorption interactions at solid–fluid interfaces, i.e. physisorption or chemisorption.


title: Lennard-Jones potential

text: It is well accepted, that the main limitations of the Lennard-Jones potential lie in the fact the potential is a pair potential (does not cover multi-body interactions) and that the formula_10 exponent term is used for the repulsion. Results from quantum chemistry suggest that a higher exponent than 12 has to be used, i.e. a steeper potential. Furthermore, the Lennard-Jones potential has a limited flexibility, i.e. only the two model parameters formula_3 and formula_4 can be used for the fitting to describe a real substance.


title: Lennard-Jones potential

text: Numerous intermolecular potentials have been proposed in the past for the modeling of simple soft repulsive and attractive interactions between spherically symmetric particles, i.e. the general shape shown in Figure 1. Examples for other potentials are the Morse potential, the Mie potential, the Buckingham potential and the Tang-Tönnies potential. Nevertheless, none of those are of such general importance as the Lennard-Jones potential.


title: Lennard-Jones potential

text: The Lennard-Jones potential is not only of fundamental importance in computational chemistry and soft-matter physics, but also for the modeling of real substances. The Lennard-Jones potential is frequently used for fundamental studies on the behavior of matter and for elucidating atomistic phenomena. It is also often used for somewhat special use cases, e.g. for studying thermophysical properties of two- or four-dimensional substances (instead of the classical three spatial directions of our universe).


title: Lennard-Jones potential

text: The Lennard-Jones potential is extensively used for molecular modeling. There are essentially two ways the Lennard-Jones potential can be used for molecular modeling: (1) A real substance atom or molecule is modeled directly by the Lennard-Jones potential, which yields very good results for noble gases and methane, i.e. dispersively interacting spherical particles. In the case of methane, the molecule is assumed to be spherically symmetric and the hydrogen atoms are fused with the carbon atom to a common unit. This simplification can in general also be applied to more complex molecules, but yields usually poor results. (2) A real substance molecule is built of multiple Lennard-Jones interactions sites, which can be connected either by rigid bonds or flexible additional potentials (and eventually also consists of other potential types, e.g. partial charges). Molecular models (often referred to as 'force fields') for practically all molecular and ionic particles can be constructed using this scheme for example for alkanes.


title: Lennard-Jones potential

text: Upon using the first outlined approach, the molecular model has only the two parameters of the Lennard-Jones potential formula_3 and formula_4 that can be used for the fitting, e.g. formula_33 and formula_34 are frequently used for argon. Evidently, this approach is only a good approximation for spherical and simply dispersively interacting molecules and atoms. The direct use of the Lennard-Jones potential has the great advantage that simulation results and theories for the Lennard-Jones potential can be used directly. Hence, available results for the Lennard-Jones potential and substance can be directly scaled using the appropriate formula_3 and formula_4 (see reduced units). The Lennard-Jones potential parameters formula_3 and formula_4 can in general be fitted to any desired real substance property. In soft-matter physics, usually experimental data for the vapor–liquid phase equilibrium or the critical point are used for the parametrization; in solid-state physics, rather the compressibility, heat capacity or lattice constants are employed.


title: Lennard-Jones potential

text: The second outlined approach of using the Lennard-Jones potential as a building block of elongated and complex molecules is far more sophisticated. Molecular models are thereby tailor-made in a sense that simulation results are only applicable for that particular model. This development approach for molecular force fields is today mainly performed in soft-matter physics and associated fields such as chemical engineering, chemistry, and computational biology. A large number of force fields are based on the Lennard-Jones potential, e.g. the TraPPE force field, the OPLS force field, and the MolMod force field (an overview of molecular force fields is out of the scope of the present article). For the state-of-the-art modeling of solid-state materials, more elaborate multi-body potentials (e.g. EAM potentials) are used.


title: Lennard-Jones potential

text: There are several different ways to formulate the Lennard-Jones potential besides Eq. (1). Alternatives are:


title: Lennard-Jones potential

text: The AB form is frequently used in implementations of simulation software as it is computationally favorable. The Lennard-Jones potential can be written as


title: Lennard-Jones potential

text: where formula_3 is the bonding energy of the molecule (the energy required to separate the atoms). Applying a harmonic approximation to the potential minimum (at formula_46), the exponent formula_47 and the energy parameter formula_3 can be related to the harmonic spring constant:


title: Lennard-Jones potential

text: from which formula_47 can be calculated if formula_51 is known. If changes in the harmonic states formula_52 are known from experiment (for example, from Raman spectroscopy) then formula_53, where formula_54 and formula_55 is the reduced mass and formula_21 is the particle mass, may be used to estimate the spring constant. Alternatively formula_47 can be related to formula_58, the group velocity in a crystal, using


title: Lennard-Jones potential

text: Dimensionless reduced units can be defined based on the Lennard-Jones potential parameters, which is convenient for molecular simulations. From a numerical point of view, the advantages of this unit system include computing values which are closer to unity, using simplified equations and being able to easily scale the results. This reduced units system requires the specification of the size parameter formula_4 and the energy parameter formula_3 of the Lennard-Jones potential and the mass of the particle formula_21. All physical properties can be converted straightforwardly taking the respective dimension into account, see table. The reduced units are often abbreviated and indicated by an asterisk.


title: Lennard-Jones potential

text: In general, reduced units can also be built up on other molecular interaction potentials that consist of a length parameter and an energy parameter.


title: Lennard-Jones potential

text: Thermophysical properties of the Lennard-Jones substance, i.e. particles interacting with the Lennard-Jones potential can be obtained using statistical mechanics. Some properties can be computed analytically, i.e. with machine precision, whereas most properties can only be obtained by performing molecular simulations. The latter will in general be superimposed by both statistical and systematic uncertainties. The virial coefficients can for example be computed directly from the Lennard-potential using algebraic expressions and reported data has therefore no uncertainty. Molecular simulation results, e.g. the pressure at a given temperature and density has both statistical and systematic uncertainties. Molecular simulations of the Lennard-Jones potential can in general be performed using either molecular dynamics (MD) simulations or Monte Carlo (MC) simulation. For MC simulations, the Lennard-Jones potential formula_27 is directly used, whereas MD simulations are always based on the derivative of the potential, i.e. the force formula_65. These differences in combination with differences in the treatment of the long-range interactions (see below) can influence computed thermophysical properties.


title: Lennard-Jones potential

text: Since the "Lennard-Jonesium" is the archetype for the modeling of simple yet realistic intermolecular interactions, a large number of thermophysical properties were studied and reported in the literature. Computer experiment data of the Lennard-Jones potential is presently considered the most accurately known data in classical mechanics computational chemistry. Hence, such data is also mostly used as benchmark for the validation and testing of new algorithms and theories. The Lennard-Jones potential has been constantly used since the early days of molecular simulations. The first results from computer experiments for the Lennard-Jones potential were reported by Rosenbluth and Rosenbluth and Wood and Parker after molecular simulations on "fast computing machines" became available in 1953. Since then many studies reported data of the Lennard-Jones substance; approximately 50,000 data points are publicly available. The current state of research of thermophysical properties of the Lennard-Jones substance is summarized in the following. The most comprehensive summary and digital database was given by Stephan et al. Presently, no data repository covers and maintains this database (or any other model potential) – the concise data selection stated by the NIST website should be treated with caution regarding referencing and coverage (it contains a small fraction of the available data). Most of the data on NIST website provides non-peer-reviewed data generated in-house by NIST.


title: Lennard-Jones potential

text: Figure 2 shows the phase diagram of the Lennard-Jones fluid. Phase equilibria of the Lennard-Jones potential have been studied numerous times and are accordingly known today with good precision. Figure 2 shows results correlations derived from computer experiment results (hence, lines instead of data points are shown).


title: Lennard-Jones potential

text: The mean intermolecular interaction of a Lennard-Jones particle strongly depends on the thermodynamic state, i.e. temperature and pressure (or density). For solid states, the attractive Lennard-Jones interaction plays a dominant role – especially at low temperatures. For liquid states, no ordered structure is present compared to solid states. The mean potential energy per particle is negative. For gaseous states, attractive interactions of the Lennard-Jones potential play a minor role – since they are far distanced. The main part of the internal energy is stored as kinetic energy for gaseous states. At supercritical states, the attractive Lennard-Jones interaction plays a minor role. With increasing temperature, the mean kinetic energy of the particles increases and exceeds the energy well of the Lennard-Jones potential. Hence, the particles mainly interact by the potentials' soft repulsive interactions and the mean potential energy per particle is accordingly positive.


title: Lennard-Jones potential

text: Overall, due to the large timespan the Lennard-Jones potential has been studied and thermophysical property data has been reported in the literature and computational resources were insufficient for accurate simulations (to modern standards), a noticeable amount of data is known to be dubious. Nevertheless, in many studies such data is used as reference. The lack of data repositories and data assessment is a crucial element for future work in the long-going field of Lennard-Jones potential research.


title: Lennard-Jones potential

text: The most important characteristic points of the Lennard-Jones potential are the critical point and the vapor–liquid–solid triple point. They were studied numerous times in the literature and compiled in Ref. The critical point was thereby assessed to be located at


title: Lennard-Jones potential

text: The given uncertainties were calculated from the standard deviation of the critical parameters derived from the most reliable available vapor–liquid equilibrium data sets. These uncertainties can be assumed as a lower limit to the accuracy with which the critical point of fluid can be obtained from molecular simulation results.


title: Lennard-Jones potential

text: The uncertainties represent the scattering of data from different authors. The critical point of the Lennard-Jones substance has been studied far more often than the triple point. For both the critical point and the vapor–liquid–solid triple point, several studies reported results out of the above stated ranges. The above stated data is the presently assumed correct and reliable data. Nevertheless, the determinateness of the critical temperature and the triple point temperature is still unsatisfactory.


title: Lennard-Jones potential

text: Evidently, the phase coexistence curves (cf. figure 2) are of fundamental importance to characterize the Lennard-Jones potential. Furthermore, "Brown's characteristic curves" yield an illustrative description of essential features of the Lennard-Jones potential. Brown's characteristic curves are defined as curves on which a certain thermodynamic property of the substance matches that of an ideal gas. For a real fluid, formula_74 and its derivatives can match the values of the ideal gas for special formula_75, formula_76 combinations only as a result of Gibbs' phase rule. The resulting points collectively constitute a characteristic curve. Four main characteristic curves are defined: One 0th-order (named "Zeno curve") and three 1st-order curves (named "Amagat", "Boyle", and "Charles curve"). The characteristic curve are required to have a negative or zero curvature throughout and a single maximum in a double-logarithmic pressure-temperature diagram. Furthermore, Brown's characteristic curves and the virial coefficients are directly linked in the limit of the ideal gas and are therefore known exactly at formula_77. Both computer simulation results and equation of state results have been reported in the literature for the Lennard-Jones potential.


title: Lennard-Jones potential

text: Points on the Zeno curve Z have a compressibility factor of unity formula_78. The Zeno curve originates at the Boyle temperature formula_79, surrounds the critical point, and has a slope of unity in the low temperature limit. Points on the Boyle curve B have formula_80. The Boyle curve originates with the Zeno curve at the Boyle temperature, faintly surrounds the critical point, and ends on the vapor pressure curve. Points on the Charles curve (a.k.a. Joule-Thomson inversion curve) have formula_81 and more importantly formula_82, i.e. no temperature change upon isenthalpic throttling. It originates at formula_83 in the ideal gas limit, crosses the Zeno curve, and terminates on the vapor pressure curve. Points on the Amagat curve A have formula_84. It also starts in the ideal gas limit at formula_85, surrounds the critical point and the other three characteristic curves and passes into the solid phase region. A comprehensive discussion of the characteristic curves of the Lennard-Jones potential is given by Stephan and Deiters.


title: Lennard-Jones potential

text: Properties of the Lennard-Jones fluid have been studied extensively in the literature due to the outstanding importance of the Lennard-Jones potential in soft-matter physics and related fields. About 50 datasets of computer experiment data for the vapor–liquid equilibrium have been published to date. Furthermore, more than 35,000 data points at homogeneous fluid states have been published over the years and recently been compiled and assessed for outliers in an open access database.


title: Lennard-Jones potential

text: The vapor–liquid equilibrium of the Lennard-Jones substance is presently known with a precision, i.e. mutual agreement of thermodynamically consistent data, of formula_86 for the vapor pressure, formula_87 for the saturated liquid density, formula_86 for the saturated vapor density, formula_89 for the enthalpy of vaporization, and formula_90 for the surface tension. This status quo can not be considered satisfactory considering the fact that statistical uncertainties usually reported for single data sets are significantly below the above stated values (even for far more complex molecular force fields).


title: Lennard-Jones potential

text: Both phase equilibrium properties and homogeneous state properties at arbitrary density can in general only be obtained from molecular simulations, whereas virial coefficients can be computed directly from the Lennard-Jones potential. Numerical data for the second and third virial coefficient is available in a wide temperature range. For higher virial coefficients (up to the sixteenth), the number of available data points decreases with increasing number of the virial coefficient. Also transport properties (viscosity, heat conductivity, and self diffusion coefficient) of the Lennard-Jones fluid have been studied frequently, but the database is significantly less dense than for homogeneous equilibrium properties like formula_91 – or internal energy data. Moreover, a large number of analytical models (equations of state) have been developed for the description of the Lennard-Jones fluid (see below for details).


title: Lennard-Jones potential

text: The database and knowledge for the Lennard-Jones solid is significantly poorer than for the fluid phases, which is mainly due to the fact that the Lennard-Jones potential is less frequently used in applications for the modeling of solid substances. It was realized early that the interactions in solid phases should not be approximated to be pair-wise additive – especially for metals.


title: Lennard-Jones potential

text: Nevertheless, the Lennard-Jones potential is still frequently used in solid-state physics due to its simplicity and computational efficiency. Hence, the basic properties of the solid phases and the solid–fluid phase equilibria have been investigated several times, e.g. Refs.


title: Lennard-Jones potential

text: The Lennard-Jones substance form fcc (face centered cubic), hcp (hexagonal close-packed) and other close-packed polytype lattices – depending on temperature and pressure, cf. figure 2. At low temperature and up to moderate pressure, the hcp lattice is energetically favored and therefore the equilibrium structure. The fcc lattice structure is energetically favored at both high temperature and high pressure and therefore overall the equilibrium structure in a wider state range. The coexistence line between the fcc and hcp phase starts at formula_92 at approximately formula_93, passes through a temperature maximum at approximately formula_94, and then ends on the vapor–solid phase boundary at approximately formula_95, which thereby forms a triple point. Hence, only the fcc solid phase exhibits phase equilibria with the liquid and supercritical phase, cf. figure 2.


title: Lennard-Jones potential

text: The triple point of the two solid phases (fcc and hcp) and the vapor phase is reported to be located at:


title: Lennard-Jones potential

text: Note, that other and significantly differing values have also been reported in the literature. Hence, the database for the fcc-hcp–vapor triple point should be further solidified in the future.


title: Lennard-Jones potential

text: Mixtures of Lennard-Jones particles are mostly used as a prototype for the development of theories and methods of solutions, but also to study properties of solutions in general. This dates back to the fundamental work of conformal solution theory of Longuet-Higgins and Leland and Rowlinson and co-workers. Those are today the basis of most theories for mixtures.


title: Lennard-Jones potential

text: Mixtures of two or more Lennard-Jones components are set up by changing at least one potential interaction parameter (formula_3 or formula_4) of one of the components with respect to the other. For a binary mixture, this yields three types of pair interactions that are all modeled by the Lennard-Jones potential: 1-1, 2-2, and 1-2 interactions. For the cross interactions 1-2, additional assumptions are required for the specification of parameters formula_103 or formula_104 from formula_105, formula_106 and formula_107, formula_108. Various choices (all more or less empirical and not rigorously based on physical arguments) can be used for these co-called combination rules. The by far most frequently used combination rule is the one of Lorentz and Berthelot


title: Lennard-Jones potential

text: The parameter formula_111 is an additional state-independent interaction parameter for the mixture. The parameter formula_112 is usually set to unity since the arithmetic mean can be considered physically plausible for the cross-interaction size parameter. The parameter formula_111 on the other hand is often used to adjust the geometric mean so as to reproduce the phase behavior of the model mixture. For analytical models, e.g. equations of state, the deviation parameter is usually written as formula_114. For formula_115, the cross-interaction dispersion energy and accordingly the attractive force between unlike particles is intensified, and the attractive forces between unlike particles are diminished for formula_116.


title: Lennard-Jones potential

text: For Lennard-Jones mixtures, both fluid and solid phase equilibria can be studied, i.e. vapor–liquid, liquid–liquid, gas–gas, solid–vapor, solid–liquid, and solid–solid. Accordingly, different types of triple points (three-phase equilibria) and critical points can exist as well as different eutectic and azeotropic points. Binary Lennard-Jones mixtures in the fluid region (various types of equilibria of liquid and gas phases) have been studied more comprehensively then phase equilibria comprising solid phases. A large number of different Lennard-Jones mixtures have been studied in the literature. To date, no standard for such has been established. Usually, the binary interaction parameters and the two component parameters are chosen such that a mixture with properties convenient for a given task are obtained. Yet, this often makes comparisons tricky.


title: Lennard-Jones potential

text: For the fluid phase behavior, mixtures exhibit practically ideal behavior (in the sense of Raoult's law) for formula_117. For formula_118 attractive interactions prevail and the mixtures tend to form high-boiling azeotropes, i.e. a lower pressure than pure components' vapor pressures is required to stabilize the vapor–liquid equilibrium. For formula_119 repulsive interactions prevail and mixtures tend to form low-boiling azeotropes, i.e. a higher pressure than pure components' vapor pressures is required to stabilize the vapor–liquid equilibrium since the mean dispersive forces are decreased. Particularly low values of formula_120 furthermore will result in liquid–liquid miscibility gaps. Also various types of phase equilibria comprising solid phases have been studied in the literature, e.g. by Carol and co-workers. Also, cases exist where the solid phase boundaries interrupt fluid phase equilibria. However, for phase equilibria that comprise solid phases, the amount of published data is sparse.


title: Lennard-Jones potential

text: A large number of equations of state (EOS) for the Lennard-Jones potential/ substance have been proposed since its characterization and evaluation became available with the first computer simulations. Due to the fundamental importance of the Lennard-Jones potential, most currently available molecular-based EOS are built around the Lennard-Jones fluid. They have been comprehensively reviewed by Stephan et al.


title: Lennard-Jones potential

text: Equations of state for the Lennard-Jones fluid are of particular importance in soft-matter physics and physical chemistry since those are frequently used as starting point for the development of EOS for complex fluids, e.g. polymers and associating fluids. The monomer units of these models are usually directly adapted from Lennard-Jones EOS as a building block, e.g. the PHC EOS, the BACKONE EOS, and SAFT type EOS.


title: Lennard-Jones potential

text: More than 30 Lennard-Jones EOS have been proposed in the literature. A comprehensive evaluation of such EOS showed that several EOS describe the Lennard-Jones potential with good and similar accuracy, but none of them is outstanding. Three of those EOS show an unacceptable unphysical behavior in some fluid region, e.g. multiple van der Waals loops, while being elsewise reasonably precise. Only the Lennard-Jones EOS of Kolafa and Nezbeda was found to be robust and precise for most thermodynamic properties of the Lennard-Jones fluid. Hence, the Lennard-Jones EOS of Kolafa and Nezbeda is presently considered to be most useful choice – because robust and precise. Furthermore, the Lennard-Jones EOS of Johnson et al. was found to be less precise for practically all available reference data than the Kolafa and Nezbeda EOS. It is interesting to note that the LJ EOS Johnson et al. is yet far more often used than that of Kolafa and Nezbeda.