title: Cairo Citadel

text: More significantly, al-Kamil built or completed the palaces in the southern section of the Citadel, and became the first ruler to actually move there in 1206. In addition to the palaces, a number of other structures were built, including a mosque, a royal library, and a "hall of justice". In 1213 al-Kamil also established a horse market on what became Rumayla Square (the square between the Citadel and Sultan Hassan's mosque today), as well as a "maydan", a long open square or "hippodrome", to the west and south of the Citadel which was used for equestrian training and military parades. This was on the same site that Ahmad Ibn Tulun established a similar hippodrome in the 9th century. This work established the overall plan of the Citadel area for centuries to come: the northern part of the citadel was devoted to military functions, the southern part to the sultan's private residence and the state administration, and outside, at the southwestern foot of the Citadel, was the parade ground which remained for centuries. Al-Kamil was likely also responsible for building or completing the first water aqueduct which ran along the top of Saladin's city walls to the southwest and brought water from the Nile to the Citadel.


title: Cairo Citadel

text: Sultan al-Salih (ruled 1240-1249) subsequently moved away from the Citadel again and built himself a new fortified enclosure on Roda Island (which also became the barracks of the "Bahri" Mamluks who took power after him). Only under the Mamluks, who ruled from 1250 to 1517, did the Citadel finally become the permanent residence of the sultans.


title: Cairo Citadel

text: Under the early Bahri Mamluks, the Citadel was continuously developed and the Southern Enclosure in particular was expanded and became the site of important monumental structures. Al-Zahir Baybars, al-Mansur Qalawun, al-Ashraf Khalil and al-Nasir Muhammad each built or rebuilt the audience hall (throne hall), the main mosque, the palaces, or other structures. Unlike the earlier Ayyubid buildings, the Mamluk buildings were increasingly designed to be visible from afar and to dominate the city's skyline. Many of these structures have not survived, with few exceptions.


title: Cairo Citadel

text: Baybars (ruled 1260-1277) was the first one to split the Citadel into two areas by building the "Bab al-Qulla", the gate and wall which today separates the Southern and Northern Enclosures of the Citadel. It was named after a keep tower which he built nearby and which was later torn down by Qalawun. The gate itself was rebuilt again by al-Nasir Muhammad in 1320. The gate was intended to control access to the newly delimited Southern Enclosure which Baybars then developed into a more elaborate and more exclusive royal complex. A part of the Southern Enclosure became reserved for the harem, the private and domestic area of the sultan and his family, while another part became the site of more monumental structures whose functions were more public, ceremonial, or administrative. Among the structures he built here was one called the "Dar al-Dhahab" ("the Hall of Gold"), which he seems to have used as his private reception hall and which may have been located in the area of the present Police Museum. Another important structure he built in the area is referred to as the "Qubba al-Zahiriyya" ("the Dome of al-Zahir"), a monumental and richly decorated hall with a central dome which acted as an audience hall or throne hall. It may have been a new structure or an addition to an existing Ayyubid structure, and it was probably the predecessor of al-Nasir Muhammad's "Great Iwan". Baybars also built the Tower of the Lions ("Burj al Siba"'), a round tower which featured a stone-carved frieze of lions (Baybars' emblem) along its upper parts. The tower was obscured by later construction but its remains, including the lion carvings, were rediscovered in the late 20th century and are now visible on the northwestern side of the Police Museum.


title: Cairo Citadel

text: Sultan al-Mansur Qalawun (ruled 1279-1290) either built or significantly renovated a structure known as the "Dar al-Niyaba" which served as the palace of the sultan's vice-regent. He also demolished Baybars' "Qubba al-Zahiriyya" and replaced it with his own domed structure, the "Qubba al-Mansuriyya". More significantly in the long run, Qalawun was the first to create elite regiments of mamluks (soldiers of slave origin) who resided in the various towers of the Citadel, which earned them the name "Burji" Mamluks (Mamluks of the Tower). It was these cohorts of mamluks who would eventually dominate the sultanate during the Burji Mamluk period.


title: Cairo Citadel

text: Sultan al-Ashraf Khalil built a "qa'a" (reception hall) in 1291-1292, referred to as the "Qa'a al-Ashrafiyya." Its remains were excavated in the late 20th century and are still visible today, just west of the present-day gate called "Bab al-'Alam" (Gate of the Flag), across the terrace from the current Police Museum. The remains indicate that the walls of the hall were decorated with multi-coloured marble paneling along the lower walls (a dado), above which was a small frieze of marble mosaics with mother-of-pearl and other marble reliefs, and above all this were panels of glass mosaics with scenes of trees and palaces which are reminiscent of the mosaics of the Ummayyad Mosque and Mausoleum of Baybars in Damascus. (During excavations the mosaics were removed for study and restoration.) The hall also had a central octagonal fountain of marble and the floor was paved with marble mosaics arranged in geometric patterns. It was one of the few structures in this area which al-Nasir Muhammad did not destroy but instead re-used for various purposes, and in the Burji Mamluk period it seems to have replaced the "Dar al-Niyaba" as the palace of the vice-regent. Al-Ashraf also, once again, demolished the "qubba" or domed throne hall of his father Qalawun and replaced it with his own structure, the "Iwan al-Ashrafiyya" (the word "iwan" seems to have been used from then on for this particular type of building). This new throne hall differed from previous incarnations in one notable respect: it was painted with pictures of al-Ashraf's amirs (commanders), each with their rank inscribed above his head.


title: Cairo Citadel

text: The greatest builder of the Citadel during the Mamluk period was al-Nasir Muhammad, another son of Qalawun, who was sultan three times over a period of nearly fifty years between 1293 and 1341. It was most likely under his reign that the borders of the Southern Enclosure expanded to their current outline, in order to accommodate the new palaces and structures he built. He is responsible for several major works in the Citadel, though unfortunately most of them fell into ruin during the Ottoman period and were finally demolished by Muhammad Ali in the 19th century. In addition to his official palaces and his semi-public monuments in the Southern Enclosure, al-Nasir reserved the southeastern corner of the enclosure (the location of the al-Gawhara Palace today) for the palaces, private courtyard, and garden devoted to his harem (wives and concubines), probably as Baybars had done, called "al-Qusur al-Jawwaniyya". He also commissioned new palaces outside the Citadel but nearby for his favourite amirs, and his projects encouraged the development of areas near the Citadel, such as al-Darb al-Ahmar.


title: Cairo Citadel

text: In 1312 al-Nasir also ordered the renovation of the water aqueduct which brought water from the Nile to the Citadel. His predecessor, al-Ashraf, is responsible for building an octagonal water intake tower on the shores of the Nile, from which water was raised and transferred along the aqueduct, but al-Nasir completed the project. This improvement of the infrastructure allowed him in turn to embark on more ambitious projects within the Citadel.


title: Cairo Citadel

text: Among the most important constructions was the Ablaq Palace ("Qasr al-Ablaq"; sometimes translated as the "Striped Palace"), built in 1313-1314. Its name derived from the red-and-black "ablaq" masonry that marked its exterior. It may have been partly inspired by the palace of the same name that Sultan Baybars had built in Damascus in 1264 and in which al-Nasir resided when he visited that city. The palace was used for regular receptions and private ceremonies. It was connected to the Great Iwan (see below) by a private passage or corridor which led to the sultan's entrance in the back wall of the Iwan. The walls of the palace itself formed a part of the new outer boundary of the Citadel's enclosure: it was located on an escarpment overlooking the city below, and the escarpment, along with the foundation walls of the palace, acted as the effective outer wall of the Citadel at its western corner. Because of this, al-Nasir was able to build a loggia on the side of the palace from which he could freely observe the activities in the stables and in the "maydan" (hippodrome) at the foot of the Citadel below, as well as a private door and staircase which gave him direct access between the palace and the hippodrome.


title: Cairo Citadel

text: The interior layout of the palace consisted of a large "qa'a" (reception hall) courtyard with two unequal "iwans" (vaulted chambers open on one side) facing each other and a central dome in the middle. The larger iwan, on the northwestern side, gave access to the outside loggia with views of the city, while the southeastern one gave access to the private passage to the Great Iwan. This also served as the throne room of the palace complex. From here one could access three "inner palaces" with the same layout but located on different levels, with the last two reached by stairs. These palace sections were lined up in a row and all faced in the same direction, apparently so that every "qa'a" had a similar view of the city from its northwestern iwan. From these inner palaces the Sultan could also access the buildings of his harem (where his wives and concubines lived) in the southeastern part of the Citadel. According to historical chronicles, the palace complex was richly decorated with marble floors, marble and gold paneling (dadoes), windows of coloured glass from Cyprus, Arabic inscriptions, colorful mosaics with mother-of-pearl that featured floral patterns, and gilded ceilings painted in lapis lazuli blue.


title: Cairo Citadel

text: The location where the palace once stood has not been identified beyond doubt. Creswell suggested that a set of massive stone corbels at the foot of the walls northwest of the Mosque of Muhammad Ali would have once supported the upper levels of the palace. More recently, Nasser Rabbat argued that a much more likely site is the partly ruined terrace just below the mosque's southwestern corner (inaccessible but partly visible to visitors today), which shelters a vast space of vaulted halls. These halls would likely have been the lower levels of the palace, acting as a substructure supporting the main palace above. If this is correct, then a part of the Mosque of Muhammad Ali today would likely overlap with the former location of the palace.


title: Cairo Citadel

text: Al-Nasir demolished, yet again, the "Iwan al-Ashrafiyya" (throne hall) of his brother al-Ashraf in 1311, and replaced it with his own structure known as the Great Iwan ("al-Iwan al-Kabir"). This may have been out of a desire to make it appear even more prominent and monumental, as well as to perhaps accommodate larger ceremonies. In any case, he demolished it (either entirely or in part) and rebuilt it yet again in 1333, and it is this incarnation of the Great Iwan which survived up until the 19th century (when it was destroyed during Muhammad Ali's constructions). It was frequently cited by chroniclers as the most impressive structure in Cairo, more monumental than almost any of the Mamluk mosques. It served as the sultan's public and ceremonial throne room and continued to be used (albeit less consistently) by Mamluk sultans after him.


title: Cairo Citadel

text: Lastly, al-Nasir's other most notable contribution, and the only major structure of his reign still preserved at the Citadel, was the Mosque of al-Nasir, also situated in the Southern Enclosure. This was built in 1318 on the site of an earlier Ayyubid main mosque which he demolished in order to serve as the new grand mosque of the Citadel. Al-Nasir renovated his mosque again in 1335. Some of its huge columns were also re-used from Pharaonic-era buildings, much like the columns of the Great Iwan. While its structure is well-preserved, most of its rich marble paneling decoration was stripped away and shipped to Istanbul by the Ottoman sultan Selim I after his conquest of Egypt.


title: Cairo Citadel

text: Subsequent sultans continued to build or add to the palaces and administrative buildings inside the Citadel, though rarely with the same ambition as al-Nasir Muhammad. Sultan al-Salih Isma'il (a son of al-Nasir who reigned from 1342 to 1345) built a richly decorated palace or hall known as "al-Duhaysha" (the "little wonder") which was inaugurated in February 1344. Likewise, Sultan Hasan (another son of al-Nasir) built a lavish domed palace known as the "Qa'a al-Baysariyya", which was completed in 1360. It was over 50 meters tall and, in addition to a main hall covered by a dome, it also had a tower with an apartment for the sultan which was decorated with ivory and ebony. Other private apartments also had domes, while paintings and portraits decorated the walls. Both Isma'il and Hasan were sons of al-Nasir Muhammad. Sultan Hasan also built his massive madrasa-mosque just northwest of the Citadel, off Rumayla Square, in the 1350s and early 1360s (and still standing today). It was so large and tall that in later years it was reportedly used by rebels as a platform from which to bombard the Citadel on more than one occasion.


title: Cairo Citadel

text: The Burji Mamluk period saw little construction in the Citadel by comparison with the earlier Mamluk period. The private harem courtyard in the southeastern corner of the Southern Enclosure, known as the "hosh", became increasingly used to build new reception halls and other structures with slightly more public functions. The late Burji sultans Qaytbay and al-Ghuri built palaces in this part of the Citadel, on the site of what is now the 19th-century al-Gawhara Palace. Al-Ghuri also restored many other structures in and around the Citadel, including a major restoration/reconstruction of the Citadel's Nile aqueduct. He also restored or reconfigured the Mamluk hippodrome at the southwestern foot of the Citadel, where he installed a vast pool which received water from the restored aqueduct.


title: Cairo Citadel

text: Egypt was conquered by the Ottoman Empire in 1517 and remained under Ottoman rule for centuries. Sultan Selim I stripped the monumental Mamluk buildings of their precious materials, especially their marble panels and decoration, and shipped them to Istanbul for use in his own building projects.


title: Cairo Citadel

text: During this period the Citadel was neglected and many Mamluk structures fell into ruin, although some of the Citadel walls were rebuilt or extended in the 16th-17th centuries. Due to rivalries between different military corps in the Ottoman forces, the Citadel was divided into three areas to house three different elements of the Ottoman garrison: the Northern Enclosure housed the barracks of the Janissaries, the Southern Enclosure was used by the Ottoman pasha (governor) and his own troops, and another lower western enclosure, which contained the stables, housed the 'Azaban (or Azap) corps. Each section had its own mosque and facilities. In between them was a virtual no-man's-land where some of the former grand Mamluk buildings stood abandoned or under-used. This included the Great Iwan of al-Nasir Muhammad, whose large dome collapsed in 1521 and was never rebuilt. The Ablaq Palace was used more productively as a manufacturing center for weaving the "Kiswah", the rich cloth covering the Kaaba in Mecca, which continued to come from Cairo until the 20th century.


title: Cairo Citadel

text: Some notable structures were still created during this period. The huge round tower near the visitor entrance today, standing at the corner of the Southern and Northern Enclosures, was built by Ibrahim Pasha (the later Grand Vizier under Suleiman the Magnificent) in 1525 and is known as the "Burj al-Muqattam" ("Tower of the Muqattam Hills"). The round tower at the other corner of the two enclosures (between Bab al-Qulla and Bab al-Wastani), known now as "Burj al-Wastani" ("Middle Tower"), may also date from this time. The first mosque built in the Citadel after the Mamluk period was the Mosque of Sulayman Pasha in the Northern Enclosure, built by the Ottoman governor in 1528 for use by the Janissaries. It is one of the few mosques in Cairo that represents something close to the classical Ottoman architectural style. The lower, western enclosure which can be seen today below the Mosque of Muhammad Ali was historically the area which housed the stables of the Citadel. It's not clear when walls were first built around it, though they were likely already enclosed in Mamluk times. This enclosure was occupied by the 'Azaban soldiers, and contains the Mosque of al-'Azab which was built by Ahmad Katkhuda in 1697. (It is possible that Ahmad Katkhuda merely renovated an existing early Burji Mamluk mosque and added the present-day Ottoman-style minaret to it.) The rest of the area is presently occupied by various 19th-century buildings, including storehouses and old factories. The lower enclosure was accessed from the west through the monumental gate called "Bab al-'Azab", which was built by Radwan Katkhuda al-Julfi in 1754, probably on the site of an earlier Mamluk gate known as "Bab al-Istabl" (Gate of the Stables). The gate was modeled on the old Fatimid gate of Bab al-Futuh in the north of Cairo, but its interior facade was later remodeled into a neo-Gothic style during the Khedival period. The current visitor entrance today goes through the small gate called "Bab al-Jabal" ("Gate of the Mountain") which was built by the Ottoman governor Yakan Pasha in 1785 when he rearranged the area to build a new palace. Yakan also rebuilt a small stretch of the adjoining wall south of here.


title: Cairo Citadel

text: Muhammad Ali was a pasha of Albanian origin who was appointed by the Ottoman sultan in 1805 to restore order after the French occupation of Egypt (1798-1801). However, he subsequently established himself as "de facto" independent ruler of the country. He consolidated power through a famous and violent coup in 1811 which eliminated the remaining Mamluk class that still formed the country's elites. One of the most pivotal events of this coup took place in the Citadel. Muhammad Ali invited the Mamluk leaders to a celebration banquet in the Citadel, and as they were leaving and passing along the road leading from the upper Citadel to Bab al-Azab, regiments of his Albanian gunmen opened fire from above and massacred all of them.


title: Cairo Citadel

text: The Citadel is sometimes referred to as the "Citadel of Muhammad Ali" ( ""). It contains the Mosque of Muhammad Ali, which he built between 1828 and 1848, perched on the summit of the citadel. This Ottoman-style mosque was built in memory of Tusun Pasha, Muhammad Ali's second son who died in 1816. However, it also represents Muhammad Ali's efforts to erase symbols of the Mamluk legacy that he sought to replace. Many of the former Mamluk structures, including the Great Iwan and the Ablaq Palace of al-Nasir Muhammad, were demolished in 1825 to make way for his new mosque and its renovated surroundings. Muhammad Ali himself was eventually buried in the mosque. His mosque also replaced the nearby Mosque of al-Nasir Muhammad as the Citadel's official main mosque. Muhammad Ali's mosque, with its large dome and tall pencil-like Ottoman minarets, is one of the most prominent monuments on Cairo's skyline to this day.


title: Cairo Citadel

text: Another obvious change that Muhammad Ali enacted pertained to the uses of the Citadel's northern and southern enclosures: during the Mamluk period the Southern Enclosure was the royal residential area and the Northern Enclosure was mostly military, but Muhammad Ali built his Harem Palace (which now houses the National Military Museum) in the Northern Enclosure, erasing the old functional division between the two sections of the Citadel. He also built or rebuilt some of the walls. Notably, he rebuilt the Bab al-Qulla gate and the surrounding wall which separated the Northern and Southern enclosures from each other, giving it its current look. The gate's form today once again emulates the appearance of Bab al-Futuh but introduces some Turkish elements. In 1825 he also built the gate known as Bab al-Jadid (the "New Gate") at the point where a new carriage road entered the Citadel from the north. Around the same time he built the "Bab al-Wastani" (or "Bab al-Wustani") ("Middle Gate") where the same road continues into the Southern Enclosure (just north of the Bab al-Qulla).


title: Cairo Citadel

text: The Citadel eventually ceased to act as the residence of Egypt's ruler after Khedive Isma'il (Muhammad Ali's son and successor) moved the court to the new 'Abdin Palace, located in the newly created districts of downtown Cairo, in 1874.


title: Cairo Citadel

text: For many years up to the late 20th century, the Citadel was closed to the public and used as a military garrison and base; at first by the British Army during the British occupation and afterward up to 1946, and since then by the Egyptian military. In 1983, the Egyptian government opened a large part of the Citadel to the public and initiated refurbishment programs to convert some of its old buildings into museums, though the military retains a presence. It is now a major tourist site for both Egyptians and foreigners alike.


title: Cairo Citadel

text: To supply water to the Citadel, Saladin built an deep well known as the Well of Joseph (or "Bir Yusuf)," so-called because Saladin's birth name, Yūsif, is the Arabic equivalent of Joseph. His chief eunuch and confidant, Qaraqush, who oversaw construction of the Citadel, was also responsible for digging the well. The well is considered a masterpiece of medieval engineering and still exists today. Its shaft was divided into two sections, almost all of which is cut out of the rock itself. The upper part has a wider shaft which is surrounded by a long spiral staircase, separated from the main shaft only by a thin wall of rock. For this reason, the well is also known as the Spiral Well ("Bir al-Halazon"). The stairs could be covered with earth to make it into a ramp for oxen to travel down to its bottom. The lower part of the well was another shaft descending to the level of underground water seeping in from the Nile. At the bottom of the upper section, two oxen turned a waterwheel that brought the water up from the bottom of the well, while another waterwheel at the top of the well, also powered by oxen, brought the water up the rest of the way.


title: Cairo Citadel

text: During the reign of al-Nasir Muhammad, Saladin's well was insufficient to produce enough water for the Citadel's growing population and for al-Nasir's envisioned construction projects. To increase the volume of water, al-Nasir renovated an Ayyubid aqueduct system (probably originally completed by al-Kamil) and extended it with a new aqueduct system. This system consisted of a number of water wheels on the Nile which raised water to the top of an hexagonal tower (built by his predecessor al-Ashraf Khalil), from which the water was then transported along a series of raised aqueducts to the base of the Citadel. From the foot of the Citadel, the water was then carried up to the palaces via another system of waterwheels. However, since this water supply could not be guaranteed in the event of a siege, Saladin's well was still an essential water source.


title: Cairo Citadel

text: This small domed building just outside the Citadel to the east was built in 1495-96 by an amir called Ya'qub Shah al-Mihmandar, a man originally from Erzincan (Turkey) who joined the Mamluk ranks under Sultan Qaytbay. Because of its dome, the building has the look of a mausoleum but it is actually a structure covering access to a cistern. It has an inscription that memorializes the victory of Sultan Qaytbay's army over Ottoman forces at Adana in a battle in 1486. Today it is cut off from the Citadel and stands stranded between two highways (Salah Salem road and Kobri al-Ebageah) which pass right next to the Citadel on its eastern side.


title: Cairo Citadel

text: The mosque was built between 1830 and 1848, although not completed until the reign of Said Pasha in 1857. It is located in the Southern Enclosure and is open to the public today. The architect was Yusuf Bushnak from Istanbul and its model was the Sultan Ahmed Mosque in that city. Muhammad Ali Pasha was buried in a tomb carved from Carrara marble, in the courtyard of the mosque. His body was transferred here from Hawsh al-Basha in 1857.


title: Cairo Citadel

text: Built in 1318, during the early Bahri Mamluk period, as the royal mosque of the Citadel where the sultans of Cairo performed their Friday prayers, today this hypostyle mosque is still similar to how it looked in the 1300 though many repairs have been made and only some of its original decoration has been restored. The parts of the building relying on plastered walls have been reinforced. There have also been attempts to restore the light-blue color of the ceiling. It is located in the Southern Enclosure and is open to the public.


title: Cairo Citadel

text: Built in 1528, it was first of the Citadel's Ottoman-style mosques and is one of the few structures in Cairo closely resembling the "classical" Ottoman style of the 16th century. It is located in the Northern Enclosure, just northeast of the Harim Palace (Military Museum). It was built on the ruins of the earlier Mosque of Sidi Sariyya built by Abu-Mansur Qasta, an amir in the Fatimid era (predating the Citadel). Qasta's tomb, dated to 1140 CE, still exists in the mosque today.


title: Cairo Citadel

text: This lesser-known mosque is situated right behind the main western gate, Bab al-'Azab. Both are named after the Ottoman military regiments known as 'Azaban (or Azaps) who were housed in this part of the Citadel during the Ottoman period. The mosque was built by the Mamluk amir Ahmad Katkhuda in 1697, but it has been argued that it incorporates, or was a renovation of, an earlier Mamluk mosque or religious structure. Although not publicly accessible, it can be spotted by its pointed Ottoman-style minaret.


title: Cairo Citadel

text: Also known as Bijou Palace, is a palace and museum commissioned by Muhammad Ali Pasha in 1814. The palace was designed and constructed by artisans contracted from a variety of countries, including Greeks, Turks, Bulgarians and Albanians. Muhammad Ali's official divan or audience hall, where the pasha received guests, contains a 1000 kg chandelier sent to him by Louis-Philippe I of France. The palace also contains the throne of Muhammad Ali Pasha that was a gift from the King of Italy.


title: Cairo Citadel

text: Inaugurated in 1983, it houses a collection of unique Royal Carriages attributed to different historical periods, from the reign of Khedive Ismail until the reign of King Farouk, in addition to other collection of unique antiques related to the carriages.


title: Cairo Citadel

text: The official museum of the Egyptian Army. The museum was established in 1937 at the old building of the Egyptian Ministry of War in downtown Cairo. It was later moved to a temporary location in the Garden City district of Cairo. In November 1949 the museum was moved to the Harem Palace at the Cairo citadel. It has been renovated several times since, in 1982 and 1993.


title: Cairo Citadel

text: The museum (also sometimes referred to as the Prison Museum) is just north of the gate known as Bab al-'Alam, on a terrace commanding sweeping views of the city below. It is housed in the Citadel's former prison and contains exhibits on topics such as famous political assassinations and displays of the murder weapon used.


title: Zahhak

text: Zahhāk or Zahāk () (), also known as Zahhak the Snake Shoulder (), is an evil figure in Persian mythology, evident in ancient Persian folklore as Azhi Dahāka (), the name by which he also appears in the texts of the "Avesta". In Middle Persian he is called Dahāg () or Bēvar Asp () the latter meaning "he who has 10,000 horses". In Zoroastrianism, Zahhak (going under the name Aži Dahāka) is considered the son of Ahriman, the foe of Ahura Mazda. In the "Shāhnāmah" of Ferdowsi, Zahhāk is the son of a ruler named Merdās.


title: Zahhak

text: "Aži" (nominative "ažiš") is the Avestan word for "serpent" or "dragon". It is cognate to the Vedic Sanskrit word "ahi", "snake", and without a sinister implication.


title: Zahhak

text: The original meaning of "dahāka" is uncertain. Among the meanings suggested are "stinging" (source uncertain), "burning" (cf. Sanskrit "dahana"), "man" or "manlike" (cf. Khotanese "daha"), "huge" or "foreign" (cf. the Dahae people and the Vedic dasas). In Persian mythology, "Dahāka" is treated as a proper noun, while the form "Zahhāk", which appears in the "Shāhnāme", was created through the influence of the unrelated Arabic word "ḍaḥḥāk" (ضَحَّاك) meaning "one who laughs".


title: Zahhak

text: The Avestan term "Aži Dahāka" and the Middle Persian "azdahāg" are the source of the Middle Persian Manichaean demon of greed "Az", Old Armenian mythological figure "Aždahak", Modern Persian '"aždehâ"/"aždahâ'," Tajik Persian '"azhdahâ'," Urdu '"azhdahā"' (اژدها), as well as the Kurdish "ejdîha" (ئەژدیها) which usually mean "dragon".


title: Zahhak

text: The name also migrated to Eastern Europe, assumed the form "azhdaja" and the meaning "dragon", "dragoness" or "water snake" in Balkanic and Slavic languages.


title: Zahhak

text: Despite the negative aspect of "Aži Dahāka" in mythology, dragons have been used on some banners of war throughout the history of Iranian peoples.


title: Zahhak

text: The Azhdarchid group of pterosaurs are named from a Persian word for "dragon" that ultimately comes from "Aži Dahāka".


title: Zahhak

text: Aži Dahāka is the most significant and long-lasting of the "aži"s of the Avesta, the earliest religious texts of Zoroastrianism. He is described as a monster with three mouths, six eyes, and three heads, cunning, strong, and demonic. In other respects Aži Dahāka has human qualities, and is never a mere animal.


title: Zahhak

text: Aži Dahāka appears in several of the Avestan myths and is mentioned parenthetically in many more places in Zoroastrian literature.


title: Zahhak

text: In a post-Avestan Zoroastrian text, the "Dēnkard", Aži Dahāka is possessed of all possible sins and evil counsels, the opposite of the good king Jam (or Jamshid). The name Dahāg (Dahāka) is punningly interpreted as meaning "having ten ("dah") sins". His mother is Wadag (or Ōdag), herself described as a great sinner, who committed incest with her son.


title: Zahhak

text: In the Avesta, Aži Dahāka is said to have lived in the inaccessible fortress of Kuuirinta in the land of Baβri, where he worshipped the yazatas Arədvī Sūrā (Anāhitā), divinity of the rivers, and Vayu divinity of the storm-wind. Based on the similarity between Baβri and Old Persian Bābiru (Babylon), later Zoroastrians localized Aži Dahāka in Mesopotamia, though the identification is open to doubt. Aži Dahāka asked these two yazatas for power to depopulate the world. Being representatives of the Good, they refused.


title: Zahhak

text: In one Avestan text, Aži Dahāka has a brother named Spitiyura. Together they attack the hero Yima (Jamshid) and cut him in half with a saw, but are then beaten back by the yazata Ātar, the divine spirit of fire.


title: Zahhak

text: According to the post-Avestan texts, following the death of Jam ī Xšēd (Jamshid), Dahāg gained kingly rule. Another late Zoroastrian text, the "Mēnog ī xrad", says this was ultimately good, because if Dahāg had not become king, the rule would have been taken by the immortal demon Xešm (Aēšma), and so evil would have ruled upon the earth until the end of the world.


title: Zahhak

text: Dahāg is said to have ruled for a thousand years, starting from 100 years after Jam lost his Khvarenah, his royal glory (see Jamshid). He is described as a sorcerer who ruled with the aid of demons, the daevas (divs).


title: Zahhak

text: The Avesta identifies the person who finally disposed of Aži Dahāka as Θraētaona son of Aθβiya, in Middle Persian called Frēdōn. The Avesta has little to say about the nature of Θraētaona's defeat of Aži Dahāka, other than that it enabled him to liberate Arənavāci and Savaŋhavāci, the two most beautiful women in the world. Later sources, especially the Dēnkard, provide more detail. Feyredon is said to have been endowed with the divine radiance of kings ("Khvarenah", New Persian "farr") for life, and was able to defeat Dahāg, striking him with a mace. However, when he did so, vermin (snakes, insects and the like) emerged from the wounds, and the god Ormazd told him not to kill Dahāg, lest the world become infected with these creatures. Instead, Frēdōn chained Dahāg up and imprisoned him on the mythical Mt. Damāvand (later identified with Damāvand).


title: Zahhak

text: The Middle Persian sources also prophesy that at the end of the world, Dahāg will at last burst his bonds and ravage the world, consuming one in three humans and livestock. Kirsāsp, the ancient hero who had killed the Az ī Srūwar, returns to life to kill Dahāg.


title: Zahhak

text: In Ferdowsi's epic poem, the Shāhnāmah, written c. 1000 AD and part of Iranian folklore, the legend is retold with the main character given the name of Zahhāk and changed from a supernatural monster into an evil human being.


title: Zahhak

text: According to Ferdowsi, Zahhāk was born as the son of a ruler named Merdās (). Because of his Arab lineage, he is sometimes called Zahhāk-e Tāzī (), meaning "Zahhāk the Tayyi". He is handsome and clever, but has no stability of character and is easily influenced by his counselors. Ahriman therefore chooses him as a tool to sow disorder and chaos. When Zahhāk is a young man, Ahriman first appears to him as a glib, flattering companion, and by degrees convinces him to kill his own father and inherit his kingdom, treasures and army. Zahhāk digs a deep pit covered over with leaves in a path to a garden where Merdās would pray each morning; Merdās falls in and is killed. Zahhāk thus ascends to the throne.


title: Zahhak

text: Ahriman then presents himself to Zahhāk as a marvelous cook. After he presents Zahhāk with many days of sumptuous feasts (introducing meat to the formerly vegetarian human cuisine), Zahhāk is willing to give Ahriman whatever he wants. Ahriman merely asks to kiss Zahhāk on his two shoulders, and Zahhāk permits this. Ahriman places his lips upon Zahhāk's shoulders and suddenly disappears. At once, two black snakes grow from Zahhāk's shoulders. They cannot be surgically removed, as another snake grows to replace one that has been severed. Ahriman appears to Zahhāk in the form of a skilled physician. He counsels Zahhāk that attempting to remove the snakes is fruitless, and that the only means of soothing the snakes and preventing them from killing him is to sate their hunger by supplying them with a stew made from two human brains every day.


title: Zahhak

text: At this time, Jamshid, the ruler of the world, becomes arrogant and loses his divine right to rule. Zahhāk presents himself as a savior to discontented Iranians seeking a new ruler. Collecting a great army, Zahhāk hunts Jamshid for many years before finally capturing him. Zahhāk executes Jamshid by sawing him in half and ascends to Jamshid's prior throne. Among his slaves are two of Jamshid's daughters, Arnavāz and Shahrnāz (the Avestan Arənavāci and Savaŋhavāci). Each day, Zahhāk's agents seize two men and execute them so that their brains can feed Zahhāk's snakes. Two men, called Armayel and Garmayel, seek to rescue people from being killed from the snakes by learning cookery and becoming Zahhāk's royal chefs. Each day, Armayel and Garmayel save one of the two men by sending him off to the mountains and faraway plains, and substitute the man's brain with that of a sheep. The saved men are the mythological progenitors of the Kurds.


title: Zahhak

text: Zahhāk's tyranny over the world lasts for centuries. One night, Zahhāk dreams of three warriors attacking him. The youngest warrior knocks Zahhāk down with his mace, ties him up, and drags him off toward Mount Damāvand as a large crowd follows. Zahhāk wakes and shouts so loudly that the pillars of the palace shake. Following Arnavāz's counsel, Zahhāk summons wise men and scholars to interpret his dream. His hesitant counsellors remain silent until the most fearless of the men reports that the dream is a vision of the end of Zahhāk's reign at the hands of Fereydun, the young man with the mace. Zahhāk is thrilled to learn the identity of his enemy, and orders his agents to search the entire country for Fereydun and capture him. The agents learn that Fereydun is a boy being nourished on the milk of the marvelous cow Barmāyeh. The spies trace Barmāyeh to the highland meadows where it grazes, but Fereydun and his mother have already fled before them. The agents kill the cow, but are forced to return to Zahhāk with their mission unfulfilled.


title: Zahhak

text: Zahhāk lives the next few years in fear and anxiety of Fereydun, and thus writes a document testifying to the virtue and righteousness of his kingdom that would be certified by the kingdom's elders and social elite, in the hope that his enemy would be convinced against exacting vengeance. Much of the summoned assembly indulge the testimony out of fear for their lives. However, a blacksmith named Kāva (Kaveh) speaks out in anger for his children having been murdered to feed Zahhāk's snakes, and for his final remaining son being sentenced to the same fate. Zahhāk orders for Kāva's son to be released in a bid to coerce Kāva into certifying the document, but Kāva tears up the document, leaves the court, and creates a flag out of his blacksmith's apron as a standard of rebellion – the Kāviyāni Banner, "derafsh-e Kāviyānī" (درفش کاویانی). Kāva proclaims himself in support of Fereydun as ruler, and rallies a crowd to follow him to the Alborz mountains, where Fereydun is now living as a young man. Fereydun agrees to lead the people against Zahhāk and has a mace made for him with a head like that of an ox.


title: Zahhak

text: Fereydun goes forth to fight against Zahhāk, who has already left his capital, which falls to Fereydun with small resistance. Fereydun frees all of Zahhāk's prisoners, including Arnavāz and Shahrnāz. Kondrow, Zahhāk's treasurer, pretends to submit to Fereydun, but discreetly escapes to Zahhāk and reports to him what has happened. Zahhāk initially dismisses the matter, but he is incensed to learn that Fereydun has seated Jamshid's daughters on thrones beside him like his queens, and immediately hastens back to his city to attack Fereydun. Zahhāk finds his capital held strongly against him, and his army is in peril from the defense of the city. Seeing that he cannot reduce the city, he sneaks into his own palace as a spy and attempts to assassinate Arnavāz and Shahrnāz. Fereydun strikes Zahhāk down with his ox-headed mace, but does not kill him; on the advice of an angel, he binds Zahhāk and imprisons him in a cave underneath Mount Damāvand. Fereydun binds Zahhāk with a lion's pelt tied to great nails fixed into the walls of the cavern, where Zahhāk will remain until the end of the world.


title: Zahhak

text: "Zahhak Castle" is the name of an ancient ruin in Hashtrud, East Azerbaijan Province, Iran which according to various experts, was inhabited from the second millennia BC until the Timurid-era. First excavated in the 19th century by British archeologists, Iran's Cultural Heritage Organization has been studying the structure in 6 phases.


title: Zahhak

text: Besides Aži Dahāka, several other dragons and dragon-like creatures are mentioned in Zoroastrian scripture:


title: Zahhak

text: Stories of monstrous serpents who are killed or imprisoned by heroes or divine beings may date back to prehistory and are found in the myths of many Indo-European peoples, including those of the Indo-Iranians, that is, the common ancestors of both the Iranians and Vedic Indians.


title: Zahhak

text: The most obvious point of comparison is that in Vedic Sanskrit "ahi" is a cognate of Avestan "aži". However, In Vedic tradition, the only dragon of importance is Vrtra, but "there is no Iranian tradition of a dragon such as Indian Vrtra" (Boyce, 1975:91-92). Moreover, while Iranian tradition has numerous dragons, all of which are malevolent, Vedic tradition has only one other dragon besides - "ahi budhnya", the benevolent "dragon of the deep". In the Vedas, gods battle dragons, but in Iranian tradition, this is a function of mortal heroes.


title: Zahhak

text: Thus, although it seems clear that dragon-slaying heroes (and gods in the case of the Vedas) "were a part of Indo-Iranian tradition and folklore, it is also apparent that Iran and India developed distinct myths early." (Skjaervø, 1989:192)


title: Dentons

text: Dentons is the largest multinational law firm in the world. Dentons was ranked as the world's 4th-largest law firm by revenue, with $2.9B gross revenue by Global 200 ranking in the fiscal year 2021. The firm is called Dentons in all languages other than Chinese, in which it is called 大成 (Dacheng).


title: Dentons

text: Dentons was founded in March 2013 by the merger of SNR Denton, Fraser Milner Casgrain and Salans. Following its merger with Chinese law firm Dacheng in November 2015, Dentons became the largest law firm in the world by number of lawyers and has the most offices of any law firm in the world, covering every continent.


title: Dentons

text: As of 2020, Dentons operates in 77 countries, has 190 offices. The firm has no headquarters, although the firm's senior leadership are primarily based in Beijing, London and Washington D.C. Dentons is structured as a Swiss Verein called Dentons Group (a Swiss Verein), which does not itself provide legal services. The verein encapsulates multiple co-operating legal entities, namely Dentons Canada LLP, Dentons Europe LLP, Dentons UK and Middle East LLP, Dentons US LLP, amongst others.


title: Dentons

text: On 11 November 2012, SNR Denton, Salans and the Canada-based Fraser Milner Casgrain announced a three-way merger, forming a new law firm structured as a Swiss Verein and named Dentons. The partners of the three firms ratified the merger on 28 November 2012, and it was completed on 28 March 2013. Dentons opened an office in Houston, Texas in September 2013.


title: Dentons

text: On January 26, 2015, Dentons announced that it was combining with a Chinese firm, Dacheng () which was completed in November 2015. The new firm is called 大成 in Chinese, and Dentons in other languages. The logo features the Chinese characters for Dacheng globally, with the lettering 大成 Dentons. Following the combination, Dentons surpassed Baker & McKenzie and DLA Piper, the world's previous top law firms by headcount, by at least 2,500 lawyers.


title: Dentons

text: In April 2015, Dentons US agreed to a merger with Atlanta-based law firm McKenna Long & Aldridge which was completed in June of that year. The firm also opened new offices in Hungary, Luxembourg and South Africa during 2015 and announced combinations with firms in Australia, Colombia, and Mexico. It also launched Nextlaw Labs, a business accelerator focused on new technologies., in May 2015. Dentons also announced in November 2016 that it would become the first global law firm with a footprint in Central America by combining with Muñoz Global, adding offices in Panama, Nicaragua and Costa Rica operating as Dentons Muñoz was created as the Costa Rican and Central American chapter of Dentons.


title: Dentons

text: In April 2016, Dentons launched in Singapore by combining with the oldest and one of the most prestigious law firms in Singapore, Rodyk & Davidson. In December 2016, Dentons launched in Australia and Papua New Guinea by combining with leading Australian law firm Gadens. The Sydney, Perth and Port Moresby offices of Gadens joined Dentons, while the Adelaide and Brisbane offices became "associate offices" and the Melbourne office remained independent. The Gadens combination resulted in Dentons having approximately 7,600 lawyers serving 57 countries.


title: Dentons

text: In 2017, Dentons merged with Scottish firm Maclay Murray & Spens. In 2017 the firm formed a strategic alliance with opposition research firm Definers Public Affairs, dubbed 3D Global Affairs. As of April 12 of 2018, Dentons announced partnerships in Kenya, Mauritius, Caribbean, Indonesia and Malaysia.


title: Dentons

text: In 2019, Dentons combined with Bingham Greenebaum Doll (from the Midwest) and Pittsburgh-based Cohen & Grigsby. The mergers were the first in a campaign called “Operation Golden Spike”. Firms that join Golden Spike operate on a dual partnership model where lawyers remain part of their existing firms while also becoming partners of the new Dentons U.S. firm. Golden Spike is part of Dentons plan to become the first U.S. law firm with a presence in all 20 of the largest U.S. markets.


title: Rhett Akins

text: Thomas Rhett Akins Sr. (born October 13, 1969) is an American singer and songwriter. Signed to Decca Records between 1994 and 1997, he released two albums for that label (1995's "A Thousand Memories" and 1996's "Somebody New"), followed by 1998's "What Livin's All About" on MCA Nashville. "Friday Night in Dixie" was released in 2002 on Audium Entertainment. Overall, his albums have accounted for fourteen singles on the "Billboard" Hot Country Songs, including the number one "Don't Get Me Started" from 1996.


title: Rhett Akins

text: Although he has not charted a single since 2006, Akins has written singles for other country music singers, primarily as one-third of the songwriting team The Peach Pickers, alongside Dallas Davidson and Ben Hayslip. Akins's son, Thomas Rhett, is also a singer.


title: Rhett Akins

text: Rhett Akins was born on October 13, 1969, in Valdosta, Georgia, to Pamela LaHood and Thomas Akins. By age 11, he and his two younger brothers had formed a band. Rhett played football at the University of Georgia and studied business but gave up his studies after a year. He then worked for his father’s oil and gas distribution company.


title: Rhett Akins

text: In 1992, after performing in the theme park show "Music Country Music" at Fiesta Texas in San Antonio, Texas, Akins moved to Nashville, Tennessee, and performed in "Country Music USA" at Opryland Theme Park. Akins then became a demo singer before Decca Records signed him to a recording contract.


title: Rhett Akins

text: Akins's first single was "What They're Talkin' About", a No. 35 on the "Billboard" country charts in late 1994, followed by the No. 36 "I Brake for Brunettes". After these first two singles came his signature song, "That Ain't My Truck". This was his breakthrough hit, peaking at No. 3 on the country charts in mid-1995. All three of these songs were included on his 1995 debut album "A Thousand Memories", which also produced the No. 17 "She Said Yes". Also in 1995 and 1996, Akins toured with Reba McEntire. In 1995, he was named one of "Country America's" "Top New Stars".


title: Rhett Akins

text: Akins' second album, "Somebody New", produced his only number one hit in "Don't Get Me Started", which peaked in August 1996. The other three singles from "Somebody New" were less successful, with "Love You Back" (the second single) becoming his last top 40 hit at No. 38.


title: Rhett Akins

text: After Decca's Nashville division was merged into MCA Nashville in 1997, Akins was transferred to MCA Nashville for the release of his third album, 1998's "What Livin's All About". This album was even less successful, however, with its lead-off single "More Than Everything" falling one space short of top 40 in the U.S., although it was a No. 25 hit on the "RPM" country charts in Canada. Also in 1998, Akins charted with a cover of Eddie Rabbitt's 1980 number one hit "Drivin' My Life Away", which Akins covered on the soundtrack to the 1998 film "Black Dog".


title: Rhett Akins

text: In 2000, he voiced the character of Tom Sawyer in MGM's animated remake of "Tom Sawyer" alongside fellow country singer Mark Wills, who voiced Huckleberry Finn, as well as Lee Ann Womack, who voiced Becky's singing voice. A fourth album, "Friday Night in Dixie", was released in 2002 on Koch Records. This album's only two singles, "Highway Sunrise" and "In Your Love", peaked at No. 55 and No. 57, respectively.


title: Rhett Akins

text: Akins did not release another single until his signing with BNA Records in 2005, when he released the No. 57-peaking "Kiss My Country Ass", which was later recorded by Blake Shelton for his 2010 extended play "Hillbilly Bone". It was included on his album "People Like Me", which was originally to have been released via BNA on June 14, 2006, but was ultimately self-released in June 2007. "If Heaven Wasn't So Far Away" was the second single from "People Like Me", which failed to chart for Akins, but was later recorded by Justin Moore, whose version went to number 1. "Down South" followed in 2008, as did its only single, the title track, which again failed to chart.


title: Rhett Akins

text: In 2009, Akins released the single "Hung Up", which did not chart. It was later included on the 2010 album "Michael Waddell's Bone Collector: The Brotherhood Album", a collaboration with fellow country music singer Dallas Davidson, released through Reprise Records Nashville.


title: Rhett Akins

text: In the late 2000s, Akins began writing songs for other artists, primarily with Ben Hayslip and Dallas Davidson, collaboratively known as The Peach Pickers. Among the singles that Akins has co-written are "Put a Girl in It" recorded by Brooks & Dunn, "Barefoot and Crazy" by Jack Ingram, "Gimmie That Girl" and "The Shape I'm In" by Joe Nichols, "All About Tonight", "Honey Bee", "I Lived It", and "Boys 'Round Here" by Blake Shelton, "When She Says Baby", "Just Gettin' Started", "Tonight Looks Good on You" by Jason Aldean, "All Over Me" by Josh Turner, "Hot Mess" by Tyler Farr, "Farmer's Daughter" and "Take a Back Road" by Rodney Atkins, "Bait a Hook" and "Point at You" by Justin Moore, "I Can Take It from There" by Chris Young, "I Know Somebody" by LoCash, "Parking Lot Party", "That Don't Sound Like You" by Lee Brice, "Hey Girl" by Billy Currington, "I Don't Want This Night to End", "Huntin', Fishin' and Lovin' Every Day" by Luke Bryan, "Wild in Your Smile", "Mind Reader", "Small Town Boy" by Dustin Lynch, "It Goes Like This", "Get Me Some of That" and "Star of the Show" by Thomas Rhett, "Granddaddy's Gun" by Aaron Lewis and "A Buncha Girls", "Young & Crazy" by Frankie Ballard, "Kick It in the Sticks", "Small Town Throwdown" by Brantley Gilbert., "Ready Set Roll" by Chase Rice, "Dirt on My Boots" by Jon Pardi and "Missing" by William Michael Morgan.


title: Rhett Akins

text: Akins married Paige Braswell in 1989, but they have since divorced. They have a son, Thomas Rhett Akins Jr. (born March 30, 1990) and a daughter, Kasey Lee Akins (born 1993). The younger Rhett is also a country music singer.


title: Denise Di Novi

text: The daughter of jazz musician Gene DiNovi, when Di Novi was three years old her family moved to Los Angeles from New York, where her father made music for the TV shows of Danny Thomas, Dick Van Dyke and Andy Griffith. In the late 1960s, the family moved to Toronto, Canada.


title: Denise Di Novi

text: Di Novi studied communications at Simmons College in Massachusetts, and received a degree in journalism. After working as a copy editor at the "National Observer" and staff writer for Canada AM, she became a reporter for Toronto's Citytv, but quit in 1980, taking a job as a unit publicist for "Final Assignment". She became a principal in the Montreal-based production company Filmplan International, acting in various production capacities on nine major studio releases, including "Scanners" (1981) and "Videodrome" (1983). In 1983, Filmplan relocated to Los Angeles and merged with Arnold Kopelson's Film Packages.


title: Denise Di Novi

text: Di Novi joined New World Pictures as Executive Vice President of production. She later shifted into an overall deal as an independent producer, producing "Heathers" (1988) starring Winona Ryder. Di Novi then headed Tim Burton Productions and was responsible for producing several films. She set up her own production company, Di Novi Pictures, in 1993, at Columbia Pictures. She then entered into a producing deal with Warner Brothers Pictures.


title: Denise Di Novi

text: Di Novi has produced 35 films. These include six from her partnership with Tim Burton, "Edward Scissorhands" (1990), "Batman Returns" (1992), "The Nightmare Before Christmas" (1993), "Cabin Boy" (1994), "Ed Wood" (also 1994) and "James and the Giant Peach" (1996). She produced four films based on books by Nicholas Sparks, "Message in a Bottle" (1999), "A Walk to Remember" (2002), "Nights in Rodanthe" (2008) and "The Lucky One" (2012).


title: Denise Di Novi

text: For four years, Di Novi was executive producer of "The District", a CBS primetime series created by Terry George. Di Novi made her directorial debut on the thriller "Unforgettable" (2017), for Warner Bros.


title: Pearl Aday

text: Pearl Aday (born 1975) is an American singer. She is the adopted daughter of vocalist Michael Lee Aday, better known as Meat Loaf, and was a member of his touring band Neverland Express for nine years starting in the mid-1990s. She has appeared on numerous albums and in various tours and television performances with her father, both as backing singer and in duets. She has also been a backing singer for Mötley Crüe. She is currently the lead singer of her own band "Pearl" and has released her debut album on Megaforce/RED/Sony Music on January 19, 2010. Aday also co-organized the hard rock group Motor Sister with her husband Scott Ian, singing backing vocals.


title: Pearl Aday

text: Aday was born to Leslie G. Edmonds and Clark Pierson, who was a drummer in singer Janis Joplin’s group, Full Tilt Boogie Band. She was adopted by Meat Loaf as a young child, after his marriage to Leslie. Pearl has a half sister named Amanda Aday.


title: Pearl Aday

text: Aday attended High School in Redding, Connecticut graduating from Joel Barlow High School in 1993. Her senior year she was the lead in the Senior Class Play "How to Succeed in Business Without Really Trying". Aday went to Emerson College in Boston, Massachusetts, majoring in creative writing, but shortly thereafter began a music career.


title: Pearl Aday

text: In 1994, she was a backing singer for Meat Loaf's 1994 Everything Louder summer tour promoting the album "", as well as the follow-up tour in 1996, "Born to Rock." She was a member of her father's backing band when they performed at the inaugural ball in 1997 for Bill Clinton. She became a full-fledged member of Neverland Express, Meat Loaf's touring band, from 1998-2003. In 2003, she sang on Meat Loaf's album "Couldn't Have Said It Better" on the duet "Man of Steel." On October 31, 2007 Pearl supported Meat Loaf one concert on his Seize the Night tour.


title: Pearl Aday

text: She was featured on an album by the band Filter and was a backing singer for Mötley Crüe on their "Maximum Rock" tour, featured on the DVD release of the tour, "Lewd, Crued, and Tattooed." She was also with a Los Angeles-based band named Stella, fronted by Nancy Hower (""), which broke up before releasing an album. She currently releases music with Pearl, a band in which she is the lead singer. The other musicians in the band are Mother Superior, best known for their work in The Rollins Band with Henry Rollins.


title: Pearl Aday

text: Aday is married to Anthrax guitarist Scott Ian. Her photographs appeared on "Music of Mass Destruction: Live from Chicago" released by Anthrax in 2004.


title: Pearl Aday

text: Aday now fronts the band Pearl which also features her husband Scott on guitar. In March 2008, they opened for Velvet Revolver in the UK.


title: Pearl Aday

text: Pearl opened for Meat Loaf's Casa de Carne Tour on July 4, 2008 (Bath, UK), July 11, 2008 (Castle Howard, York, UK), July 13, 2008 (Blickling Hall, Norfolk, UK), July 21, 2008 (Zitadelle Berlin, Germany) and on July 23, 2008 (Stadtpark Hamburg, Germany). In May 2009, she appeared on the FOX game show "Don't Forget the Lyrics" along with her father Meat Loaf and his duet partner Patti Russo: they won $500,000 for charity. She headlined her own 13-date 2010 US tour before rejoining Meat Loaf as an opening act in support of the Hang Cool Tour in 2010. In support of her first album, she also appeared on the January 21, 2010 episode of "Jimmy Kimmel Live!". Both she and her husband took a break from their musical careers, as the couple had a son named Revel Young Ian on June 19, 2011.


title: Metamaterial

text: A metamaterial (from the Greek word μετά "meta", meaning "beyond" or "after", and the Latin word "materia", meaning "matter" or "material") is any material engineered to have a property that is not found in naturally occurring materials. They are made from assemblies of multiple elements fashioned from composite materials such as metals and plastics. The materials are usually arranged in repeating patterns, at scales that are smaller than the wavelengths of the phenomena they influence. Metamaterials derive their properties not from the properties of the base materials, but from their newly designed structures. Their precise shape, geometry, size, orientation and arrangement gives them their smart properties capable of manipulating electromagnetic waves: by blocking, absorbing, enhancing, or bending waves, to achieve benefits that go beyond what is possible with conventional materials.


title: Metamaterial

text: Appropriately designed metamaterials can affect waves of electromagnetic radiation or sound in a manner not observed in bulk materials. Those that exhibit a negative index of refraction for particular wavelengths have been the focus of a large amount of research. These materials are known as negative-index metamaterials.


title: Metamaterial

text: Potential applications of metamaterials are diverse and include optical filters, medical devices, remote aerospace applications, sensor detection and infrastructure monitoring, smart solar power management, Lasers, crowd control, radomes, high-frequency battlefield communication and lenses for high-gain antennas, improving ultrasonic sensors, and even shielding structures from earthquakes. Metamaterials offer the potential to create super-lenses. Such a lens can allow imaging below the diffraction limit that is the minimum resolution d=λ/(2NA) that can be achieved by conventional lenses having a numerical aperture NA and with illumination wavelength λ. Sub-wavelength optical metamaterials, when integrated with optical recording media, can be used to achieve optical data density higher than limited by diffraction. A form of 'invisibility' was demonstrated using gradient-index materials. Acoustic and seismic metamaterials are also research areas.


title: Metamaterial

text: Metamaterial research is interdisciplinary and involves such fields as electrical engineering, electromagnetics, classical optics, solid state physics, microwave and antenna engineering, optoelectronics, material sciences, nanoscience and semiconductor engineering.


title: Metamaterial

text: Explorations of artificial materials for manipulating electromagnetic waves began at the end of the 19th century. Some of the earliest structures that may be considered metamaterials were studied by Jagadish Chandra Bose, who in 1898 researched substances with chiral properties. Karl Ferdinand Lindman studied wave interaction with metallic helices as artificial chiral media in the early twentieth century.


title: Metamaterial

text: In the late 1940s, Winston E. Kock from AT&T Bell Laboratories developed materials that had similar characteristics to metamaterials. In the 1950s and 1960s, artificial dielectrics were studied for lightweight microwave antennas. Microwave radar absorbers were researched in the 1980s and 1990s as applications for artificial chiral media.


title: Metamaterial

text: Negative-index materials were first described theoretically by Victor Veselago in 1967. He proved that such materials could transmit light. He showed that the phase velocity could be made anti-parallel to the direction of Poynting vector. This is contrary to wave propagation in naturally occurring materials.


title: Metamaterial

text: In 1995, John M. Guerra fabricated a sub-wavelength transparent grating (later called a photonic metamaterial) having 50 nm lines and spaces, and then coupled it with a standard oil immersion microscope objective (the combination later called a super-lens) to resolve a grating in a silicon wafer also having 50 nm lines and spaces. This super-resolved image was achieved with illumination having a wavelength of 650 nm in air.


title: Metamaterial

text: In 2000, John Pendry was the first to identify a practical way to make a left-handed metamaterial, a material in which the right-hand rule is not followed. Such a material allows an electromagnetic wave to convey energy (have a group velocity) against its phase velocity. Pendry's idea was that metallic wires aligned along the direction of a wave could provide negative permittivity (dielectric function ε < 0). Natural materials (such as ferroelectrics) display negative permittivity; the challenge was achieving negative permeability (µ < 0). In 1999 Pendry demonstrated that a split ring (C shape) with its axis placed along the direction of wave propagation could do so. In the same paper, he showed that a periodic array of wires and rings could give rise to a negative refractive index. Pendry also proposed a related negative-permeability design, the Swiss roll.


title: Metamaterial

text: In 2000, David R. Smith et al. reported the experimental demonstration of functioning electromagnetic metamaterials by horizontally stacking, periodically, split-ring resonators and thin wire structures. A method was provided in 2002 to realize negative-index metamaterials using artificial lumped-element loaded transmission lines in microstrip technology. In 2003, complex (both real and imaginary parts of) negative refractive index and imaging by flat lens using left handed metamaterials were demonstrated. By 2007, experiments that involved negative refractive index had been conducted by many groups. At microwave frequencies, the first, imperfect invisibility cloak was realized in 2006.


title: Metamaterial

text: An electromagnetic metamaterial affects electromagnetic waves that impinge on or interact with its structural features, which are smaller than the wavelength. To behave as a homogeneous material accurately described by an effective refractive index, its features must be much smaller than the wavelength.


title: Metamaterial

text: For microwave radiation, the features are on the order of millimeters. Microwave frequency metamaterials are usually constructed as arrays of electrically conductive elements (such as loops of wire) that have suitable inductive and capacitive characteristics. Many microwave metamaterials use split-ring resonators.


title: Metamaterial

text: Photonic metamaterials are structured on the nanometer scale and manipulate light at optical frequencies. Photonic crystals and frequency-selective surfaces such as diffraction gratings, dielectric mirrors and optical coatings exhibit similarities to subwavelength structured metamaterials. However, these are usually considered distinct from metamaterials, as their function arises from diffraction or interference and thus cannot be approximated as a homogeneous material. However, material structures such as photonic crystals are effective in the visible light spectrum. The middle of the visible spectrum has a wavelength of approximately 560 nm (for sunlight). Photonic crystal structures are generally half this size or smaller, that is <280 nm.


title: Metamaterial

text: Plasmonic metamaterials utilize surface plasmons, which are packets of electrical charge that collectively oscillate at the surfaces of metals at optical frequencies.


title: Metamaterial

text: Frequency selective surfaces (FSS) can exhibit subwavelength characteristics and are known variously as artificial magnetic conductors (AMC) or High Impedance Surfaces (HIS). FSS display inductive and capacitive characteristics that are directly related to their subwavelength structure.


title: Metamaterial

text: Negative-index metamaterials (NIM) are characterized by a negative index of refraction. Other terms for NIMs include "left-handed media", "media with a negative refractive index", and "backward-wave media". NIMs where the negative index of refraction arises from simultaneously negative permittivity and negative permeability are also known as double negative metamaterials or double negative materials (DNG).


title: Metamaterial

text: Assuming a material well-approximated by a real permittivity and permeability, the relationship between permittivity formula_1, permeability formula_2 and refractive index "n" is given by


title: Metamaterial

text: formula_3. All known non-metamaterial transparent materials (glass, water, ...) possess positive formula_1 and formula_2. By convention the positive square root is used for "n". However, some engineered metamaterials have formula_1 and formula_7. Because the product formula_8 is positive, "n" is real. Under such circumstances, it is necessary to take the negative square root for "n". When both formula_1 and formula_2 are positive (negative), waves travel in the "forward" ("backward") direction. Electromagnetic waves cannot propagate in materials with formula_1 and formula_2 of opposite sign as the refractive index becomes imaginary. Such materials are opaque for electromagnetic radiation and examples include plasmonic materials such as metals (gold, silver, ...).


title: Metamaterial

text: The foregoing considerations are simplistic for actual materials, which must have complex-valued formula_1 and formula_2. The real parts of both formula_1 and formula_2 do not have to be negative for a passive material to display negative refraction. Indeed, a negative refractive index for circularly polarized waves can also arise from chirality. Metamaterials with negative "n" have numerous interesting properties:


title: Metamaterial

text: For plane waves propagating in electromagnetic metamaterials, the electric field, magnetic field and wave vector follow a left-hand rule, the reverse of the behavior of conventional optical materials.


title: Metamaterial

text: Single negative (SNG) metamaterials have either negative relative permittivity (ε) or negative relative permeability (µ), but not both. They act as metamaterials when combined with a different, complementary SNG, jointly acting as a DNG.


title: Metamaterial

text: Epsilon negative media (ENG) display a negative ε while µ is positive. Many plasmas exhibit this characteristic. For example, noble metals such as gold or silver are ENG in the infrared and visible spectrums.


title: Metamaterial

text: Mu-negative media (MNG) display a positive ε and negative µ. Gyrotropic or gyromagnetic materials exhibit this characteristic. A gyrotropic material is one that has been altered by the presence of a quasistatic magnetic field, enabling a magneto-optic effect. A magneto-optic effect is a phenomenon in which an electromagnetic wave propagates through such a medium. In such a material, left- and right-rotating elliptical polarizations can propagate at different speeds. When light is transmitted through a layer of magneto-optic material, the result is called the Faraday effect: the polarization plane can be rotated, forming a Faraday rotator. The results of such a reflection are known as the magneto-optic Kerr effect (not to be confused with the nonlinear Kerr effect). Two gyrotropic materials with reversed rotation directions of the two principal polarizations are called optical isomers.


title: Metamaterial

text: Joining a slab of ENG material and slab of MNG material resulted in properties such as resonances, anomalous tunneling, transparency and zero reflection. Like negative-index materials, SNGs are innately dispersive, so their ε, µ and refraction index n, are a function of frequency.


title: Metamaterial

text: Hyperbolic metamaterials (HMMs) behave as a metal for certain polarization or direction of light propagation and behave as a dielectric for the other due to the negative and positive permittivity tensor components, giving extreme anisotropy. The material's dispersion relation in wavevector space forms a hyperboloid and therefore it is called a hyperbolic metamaterial. The extreme anisotropy of HMMs leads to directional propagation of light within and on the surface. HMMs have showed various potential applications, such as sensing, reflection modulator, imaging, steering of optical signals, enhanced plasmon resonance effects.


title: Metamaterial

text: Electromagnetic bandgap metamaterials (EBG or EBM) control light propagation. This is accomplished either with photonic crystals (PC) or left-handed materials (LHM). PCs can prohibit light propagation altogether. Both classes can allow light to propagate in specific, designed directions and both can be designed with bandgaps at desired frequencies. The period size of EBGs is an appreciable fraction of the wavelength, creating constructive and destructive interference.


title: Metamaterial

text: PC are distinguished from sub-wavelength structures, such as tunable metamaterials, because the PC derives its properties from its bandgap characteristics. PCs are sized to match the wavelength of light, versus other metamaterials that expose sub-wavelength structure. Furthermore, PCs function by diffracting light. In contrast, metamaterial does not use diffraction.


title: Metamaterial

text: PCs have periodic inclusions that inhibit wave propagation due to the inclusions' destructive interference from scattering. The photonic bandgap property of PCs makes them the electromagnetic analog of electronic semi-conductor crystals.


title: Metamaterial

text: EBGs have the goal of creating high quality, low loss, periodic, dielectric structures. An EBG affects photons in the same way semiconductor materials affect electrons. PCs are the perfect bandgap material, because they allow no light propagation. Each unit of the prescribed periodic structure acts like one atom, albeit of a much larger size.


title: Metamaterial

text: EBGs are designed to prevent the propagation of an allocated bandwidth of frequencies, for certain arrival angles and polarizations. Various geometries and structures have been proposed to fabricate EBG's special properties. In practice it is impossible to build a flawless EBG device.


title: Metamaterial

text: EBGs have been manufactured for frequencies ranging from a few gigahertz (GHz) to a few terahertz (THz), radio, microwave and mid-infrared frequency regions. EBG application developments include a transmission line, woodpiles made of square dielectric bars and several different types of low gain antennas.


title: Metamaterial

text: Double positive mediums (DPS) do occur in nature, such as naturally occurring dielectrics. Permittivity and magnetic permeability are both positive and wave propagation is in the forward direction. Artificial materials have been fabricated which combine DPS, ENG and MNG properties.


title: Metamaterial

text: Categorizing metamaterials into double or single negative, or double positive, normally assumes that the metamaterial has independent electric and magnetic responses described by ε and µ. However, in many cases, the electric field causes magnetic polarization, while the magnetic field induces electrical polarization, known as magnetoelectric coupling. Such media are denoted as bi-isotropic. Media that exhibit magnetoelectric coupling and that are anisotropic (which is the case for many metamaterial structures), are referred to as bi-anisotropic.


title: Metamaterial

text: Four material parameters are intrinsic to magnetoelectric coupling of bi-isotropic media. They are the electric (E) and magnetic (H) field strengths, and electric (D) and magnetic (B) flux densities. These parameters are ε, µ, "κ" and χ or permittivity, permeability, strength of chirality, and the Tellegen parameter, respectively. In this type of media, material parameters do not vary with changes along a rotated coordinate system of measurements. In this sense they are invariant or scalar.


title: Metamaterial

text: The intrinsic magnetoelectric parameters, "κ" and "χ", affect the phase of the wave. The effect of the chirality parameter is to split the refractive index. In isotropic media this results in wave propagation only if ε and µ have the same sign. In bi-isotropic media with "χ" assumed to be zero, and "κ" a non-zero value, different results appear. Either a backward wave or a forward wave can occur. Alternatively, two forward waves or two backward waves can occur, depending on the strength of the chirality parameter.


title: Metamaterial

text: where formula_20 and formula_21 are the permittivity and the permeability tensors, respectively, whereas formula_22 and formula_23 are the two magneto-electric tensors. If the medium is reciprocal, permittivity and permeability are symmetric tensors, and formula_24, where formula_25 is the chiral tensor describing chiral electromagnetic and reciprocal magneto-electric response. The chiral tensor can be expressed as formula_26, where formula_27 is the trace of formula_28, I is the identity matrix, N is a symmetric trace-free tensor, and J is an antisymmetric tensor. Such decomposition allows us to classify the reciprocal bianisotropic response and we can identify the following three main classes: (i) chiral media (formula_29), (ii) pseudochiral media (formula_30), (iii) omega media (formula_31).


title: Metamaterial

text: Handedness of metamaterials is a potential source of confusion as the metamaterial literature includes two conflicting uses of the terms "left-" and "right-handed". The first refers to one of the two circularly polarized waves that are the propagating modes in chiral media. The second relates to the triplet of electric field, magnetic field and Poynting vector that arise in negative refractive index media, which in most cases are not chiral.


title: Metamaterial

text: Generally a chiral and/or bianisotropic electromagnetic response is a consequence of 3D geometrical chirality: 3D-chiral metamaterials are composed by embedding 3D-chiral structures in a host medium and they show chirality-related polarization effects such as optical activity and circular dichroism. The concept of 2D chirality also exists and a planar object is said to be chiral if it cannot be superposed onto its mirror image unless it is lifted from the plane. 2D-chiral metamaterials that are anisotropic and lossy have been observed to exhibit directionally asymmetric transmission (reflection, absorption) of circularly polarized waves due to circular conversion dichrosim. On the other hand, bianisotropic response can arise from geometrical achiral structures possessing neither 2D nor 3D intrinsic chirality. Plum and colleagues investigated magneto-electric coupling due to extrinsic chirality, where the arrangement of a (achiral) structure together with the radiation wave vector is different from its mirror image, and observed large, tuneable linear optical activity, nonlinear optical activity, specular optical activity and circular conversion dichroism. Rizza "et al." suggested 1D chiral metamaterials where the effective chiral tensor is not vanishing if the system is geometrically one-dimensional chiral (the mirror image of the entire structure cannot be superposed onto it by using translations without rotations).


title: Metamaterial

text: 3D-chiral metamaterials are constructed from chiral materials or resonators in which the effective chirality parameter formula_32 is non-zero.


title: Metamaterial

text: Wave propagation properties in such chiral metamaterials demonstrate that negative refraction can be realized in metamaterials with a strong chirality and positive formula_33 and formula_34.


title: Metamaterial

text: It can be seen that a negative index will occur for one polarization if formula_32 > formula_38. In this case, it is not necessary that either or both formula_33 and formula_34 be negative for backward wave propagation. A negative refractive index due to chirality was first observed simultaneously and independently by Plum "et al." and Zhang "et al." in 2009.


title: Metamaterial

text: Frequency selective surface-based metamaterials block signals in one waveband and pass those at another waveband. They have become an alternative to fixed frequency metamaterials. They allow for optional changes of frequencies in a single medium, rather than the restrictive limitations of a fixed frequency response.


title: Metamaterial

text: These metamaterials use different parameters to achieve a negative index of refraction in materials that are not electromagnetic. Furthermore, "a new design for elastic metamaterials that can behave either as liquids or solids over a limited frequency range may enable new applications based on the control of acoustic, elastic and seismic waves." They are also called mechanical metamaterials.


title: Metamaterial

text: Acoustic metamaterials control, direct and manipulate sound in the form of sonic, infrasonic or ultrasonic waves in gases, liquids and solids. As with electromagnetic waves, sonic waves can exhibit negative refraction.


title: Metamaterial

text: Control of sound waves is mostly accomplished through the bulk modulus "β", mass density "ρ" and chirality. The bulk modulus and density are analogs of permittivity and permeability in electromagnetic metamaterials. Related to this is the mechanics of sound wave propagation in a lattice structure. Also materials have mass and intrinsic degrees of stiffness. Together, these form a resonant system and the mechanical (sonic) resonance may be excited by appropriate sonic frequencies (for example audible pulses).


title: Metamaterial

text: Structural metamaterials provide properties such as crushability and light weight. Using projection micro-stereolithography, microlattices can be created using forms much like trusses and girders. Materials four orders of magnitude stiffer than conventional aerogel, but with the same density have been created. Such materials can withstand a load of at least 160,000 times their own weight by over-constraining the materials.


title: Metamaterial

text: Typically materials found in nature, when homogeneous, are thermally isotropic. That is to say, heat passes through them at roughly the same rate in all directions. However, thermal metamaterials are anisotropic usually due to their highly organized internal structure. Composite materials with highly aligned internal particles or structures, such as fibers, are examples of this, for example carbon nanotubes (CNT).


title: Metamaterial

text: Metamaterials may be fabricated that include some form of nonlinear media, whose properties change with the power of the incident wave. Nonlinear media are essential for nonlinear optics. Most optical materials have a relatively weak response, meaning that their properties change by only a small amount for large changes in the intensity of the electromagnetic field. The local electromagnetic fields of the inclusions in nonlinear metamaterials can be much larger than the average value of the field. Besides, remarkable nonlinear effects have been predicted and observed if the metamaterial effective dielectric permittivity is very small (epsilon-near-zero media). In addition, exotic properties such as a negative refractive index, create opportunities to tailor the phase matching conditions that must be satisfied in any nonlinear optical structure.


title: Metamaterial

text: In 2009, Marc Briane and Graeme Milton proved mathematically that one can in principle invert the sign of a 3 materials based composite in 3D made out of only positive or negative sign Hall coefficient materials. Later in 2015 Muamer Kadic et al. showed that a simple perforation of isotropic material can lead to its change of sign of the Hall coefficient. This theoretical claim was finally experimentally demonstrated by Christian Kern et al.


title: Metamaterial

text: In 2015, it was also demonstrated by Christian Kern et al. that an anisotropic perforation of a single material can lead to a yet more unusual effect namely the parallel Hall effect. This means that the induced electric field inside a conducting media is no longer orthogonal to the current and the magnetic field but is actually parallel to the latest.


title: Metamaterial

text: Terahertz metamaterials interact at terahertz frequencies, usually defined as 0.1 to 10 THz. Terahertz radiation lies at the far end of the infrared band, just after the end of the microwave band. This corresponds to millimeter and submillimeter wavelengths between the 3 mm (EHF band) and 0.03 mm (long-wavelength edge of far-infrared light).


title: Metamaterial

text: Photonic metamaterial interact with optical frequencies (mid-infrared). The sub-wavelength period distinguishes them from photonic band gap structures.


title: Metamaterial

text: Tunable metamaterials allow arbitrary adjustments to frequency changes in the refractive index. A tunable metamaterial expands beyond the bandwidth limitations in left-handed materials by constructing various types of metamaterials.


title: Metamaterial

text: Plasmonic metamaterials exploit surface plasmons, which are produced from the interaction of light with metal-dielectrics. Under specific conditions, the incident light couples with the surface plasmons to create self-sustaining, propagating electromagnetic waves or surface waves known as surface plasmon polaritons. Bulk plasma oscillations make possible the effect of negative mass (density).


title: Metamaterial

text: Metamaterials are under consideration for many applications. Metamaterial antennas are commercially available.


title: Metamaterial

text: In 2007, one researcher stated that for metamaterial applications to be realized, energy loss must be reduced, materials must be extended into three-dimensional isotropic materials and production techniques must be industrialized.


title: Metamaterial

text: Metamaterial antennas are a class of antennas that use metamaterials to improve performance. Demonstrations showed that metamaterials could enhance an antenna's radiated power. Materials that can attain negative permeability allow for properties such as small antenna size, high directivity and tunable frequency. Single-negative metamaterials such as meta-grid lines can alleviate mutual coupling in closely packed MIMO antenna arrays.


title: Metamaterial

text: A metamaterial absorber manipulates the loss components of metamaterials' permittivity and magnetic permeability, to absorb large amounts of electromagnetic radiation. This is a useful feature for photodetection and solar photovoltaic applications. Loss components are also relevant in applications of negative refractive index (photonic metamaterials, antenna systems) or transformation optics (metamaterial cloaking, celestial mechanics), but often are not utilized in these applications.


title: Metamaterial

text: A "superlens" is a two or three-dimensional device that uses metamaterials, usually with negative refraction properties, to achieve resolution beyond the diffraction limit (ideally, infinite resolution). Such a behaviour is enabled by the capability of double-negative materials to yield negative phase velocity. The diffraction limit is inherent in conventional optical devices or lenses.


title: Metamaterial

text: Metamaterials are a potential basis for a practical cloaking device. The proof of principle was demonstrated on October 19, 2006. No practical cloaks are publicly known to exist.


title: Metamaterial

text: Conventionally, the RCS has been reduced either by Radar absorbent material (RAM) or by purpose shaping of the targets such that the scattered energy can be redirected away from the source. While RAMs have narrow frequency band functionality, purpose shaping limits the aerodynamic performance of the target. More recently, metamaterials or metasurfaces are synthesized that can redirect the scattered energy away from the source using either array theory or generalized Snell's law. This has led to aerodynamically favorable shapes for the targets with the reduced RCS.


title: Metamaterial

text: Metamaterials textured with nanoscale wrinkles could control sound or light signals, such as changing a material's color or improving ultrasound resolution. Uses include nondestructive material testing, medical diagnostics and sound suppression. The materials can be made through a high-precision, multi-layer deposition process. The thickness of each layer can be controlled within a fraction of a wavelength. The material is then compressed, creating precise wrinkles whose spacing can cause scattering of selected frequencies.


title: Metamaterial

text: Metamaterials can be integrated with optical waveguides to tailor guided electromagnetic waves (meta-waveguide). Subwavelength structures like metamaterials can be integrated with for instance silicon waveguides to develop and polarization beam splitters and optical couplers, adding new degrees of freedom of controlling light propagation at nanoscale for integrated photonic devices. Other applications such as integrated mode convertors, polarization (de)multiplexers, structured light generation, and on-chip bio-sensors can be developed.


title: Metamaterial

text: All materials are made of atoms, which are dipoles. These dipoles modify light velocity by a factor "n" (the refractive index). In a split ring resonator the ring and wire units act as atomic dipoles: the wire acts as a ferroelectric atom, while the ring acts as an inductor "L, "while the open section acts as a capacitor "C". The ring as a whole acts as an LC circuit. When the electromagnetic field passes through the ring, an induced current is created. The generated field is perpendicular to the light's magnetic field. The magnetic resonance results in a negative permeability; the refraction index is negative as well. (The lens is not truly flat, since the structure's capacitance imposes a slope for the electric induction.)


title: Metamaterial

text: Several (mathematical) material models frequency response in DNGs. One of these is the Lorentz model, which describes electron motion in terms of a driven-damped, harmonic oscillator. The Debye relaxation model applies when the acceleration component of the Lorentz mathematical model is small compared to the other components of the equation. The Drude model applies when the restoring force component is negligible and the coupling coefficient is generally the plasma frequency. Other component distinctions call for the use of one of these models, depending on its polarity or purpose.


title: Metamaterial

text: Three-dimensional composites of metal/non-metallic inclusions periodically/randomly embedded in a low permittivity matrix are usually modeled by analytical methods, including mixing formulas and scattering-matrix based methods. The particle is modeled by either an electric dipole parallel to the electric field or a pair of crossed electric and magnetic dipoles parallel to the electric and magnetic fields, respectively, of the applied wave. These dipoles are the leading terms in the multipole series. They are the only existing ones for a homogeneous sphere, whose polarizability can be easily obtained from the Mie scattering coefficients. In general, this procedure is known as the "point-dipole approximation", which is a good approximation for metamaterials consisting of composites of electrically small spheres. Merits of these methods include low calculation cost and mathematical simplicity.


title: Metamaterial

text: Three conceptions- negative-index medium, non-reflecting crystal and superlens are foundations of the metamaterial theory. Other first principles techniques for analyzing triply-periodic electromagnetic media may be found in Computing photonic band structure


title: Metamaterial

text: The Multidisciplinary University Research Initiative (MURI) encompasses dozens of Universities and a few government organizations. Participating universities include UC Berkeley, UC Los Angeles, UC San Diego, Massachusetts Institute of Technology, and Imperial College in London. The sponsors are Office of Naval Research and the Defense Advanced Research Project Agency.


title: Metamaterial

text: MURI supports research that intersects more than one traditional science and engineering discipline to accelerate both research and translation to applications. As of 2009, 69 academic institutions were expected to participate in 41 research efforts.


title: Metamaterial

text: The Virtual Institute for Artificial Electromagnetic Materials and Metamaterials "Metamorphose VI AISBL" is an international association to promote artificial electromagnetic materials and metamaterials. It organizes scientific conferences, supports specialized journals, creates and manages research programs, provides training programs (including PhD and training programs for industrial partners); and technology transfer to European Industry.


title: Kurt Meyer

text: Kurt Meyer (23 December 1910 – 23 December 1961) was an SS commander and convicted war criminal of Nazi Germany. He served in the Waffen-SS (the combat branch of the SS) and participated in the Battle of France, Operation Barbarossa, and other engagements during World War II. Meyer commanded the 12th SS Panzer Division Hitlerjugend during the Allied invasion of Normandy, and was a recipient of the Knight's Cross of the Iron Cross with Oak Leaves and Swords.


title: Kurt Meyer

text: After ordering the mass murder of civilians and prisoners of war (POWs) several times during the conflict, Meyer was convicted of war crimes for his role in the Ardenne Abbey massacre (the murder of Canadian POWs in Normandy). He was sentenced to death, but the sentence was later commuted to life in prison.


title: Kurt Meyer

text: He became active in HIAG, a lobby group organised by former high-ranking Waffen-SS men, after his release. Meyer was a leading Waffen-SS apologist and HIAG's most effective spokesperson, depicting most of the Waffen-SS as apolitical, recklessly brave fighters who were not involved in the crimes of the Nazi regime. These notions have since been debunked by historians.


title: Kurt Meyer

text: Born in 1910 in Jerxheim, Meyer came from a lower-class working family. His father, a miner, joined the German Army in 1914 and was an in World War I. Meyer began a business apprenticeship after completing elementary school, but became unemployed in 1928 and was forced to work as a handyman before becoming a policeman in Mecklenburg-Schwerin the following year.


title: Kurt Meyer

text: Politically active at an early age and a fanatical supporter of Nazism, Meyer joined the Hitler Youth when he was fifteen, became a full member of the Nazi Party in September 1930, and joined the SS in October 1931. He was a guest at the marriage of Joseph Goebbels in December of that year. In May 1934, Meyer was transferred to the Leibstandarte SS Adolf Hitler (LSSAH). With this unit (which later became part of the Waffen-SS, the combat branch of the SS), Meyer took part in the annexation of Austria in 1938 and the 1939 occupation of Czechoslovakia.


title: Kurt Meyer

text: At the outbreak of World War II, Meyer participated in the invasion of Poland with the LSSAH, serving as commander for an anti-tank company (namely "14. Panzerabwehrkompanie"). He was awarded the Iron Cross, Second Class, on 20September 1939. In October, Meyer allegedly ordered the shooting of fifty Polish Jews as a reprisal near Modlin and court-martialled a platoon commander who refused to carry out his instructions. He participated in the Battle of France and was awarded the Iron Cross, First Class.


title: Kurt Meyer

text: Following the Battle of France, Meyer's company was reorganized into the LSSAH's reconnaissance battalion and he was promoted. Benito Mussolini's unsuccessful invasion of Greece prompted Germany to invade Yugoslavia and Greece in April 1941. During the invasion, the battalion came under fire from the Greek Army defending the Klisura Pass. After heavy fighting, Meyer's troops broke through the defensive lines; with the road now open, the German forces drove through to the Kastoria area to cut off retreating Greek and British Commonwealth forces. After the campaign, Meyer was awarded the Knight's Cross of the Iron Cross.


title: Kurt Meyer

text: The LSSAH Division (including Meyer and his battalion) participated in Operation Barbarossa, the invasion of the Soviet Union, in June 1941 as part of Army Group South. He and his unit quickly became infamous even among the LSSAH Division for mass-murdering civilians and destroying entire villages, such as when they murdered about 20 women, children, and old men at Rowno. According to historian Jens Westemeier, Meyer was primarily responsible for the brutalization of the troops under his command. His terror tactics were regarded with approval by the Waffen-SS command. In combat against the Red Army, Meyer and his unit also achieved some military successes, while suffering the heaviest casualties among the LSSAH's battalions. He gained a reputation as an "audacious" leader during Operation Barbarossa, and was awarded the German Cross in Gold in 1942 while still with the LSSAH.


title: Kurt Meyer

text: In early 1943, Meyer's reconnaissance battalion participated in the Third Battle of Kharkov. He reportedly ordered the destruction of a village during the fighting around Kharkov and the murder of all its inhabitants. Different accounts of the events exist, though they share a general outline. Meyer was awarded the Knight's Cross with Oak Leaves for a successful attack on the village of Yefremovka (Jefremowka) on 20 February 1943, where his forces took no prisoners and killed about 1500 Soviet soldiers. After the war, a former SS man described an incident which took place on Meyer's orders in Jefremowka in March 1943, following its occupation. Billeted in the village, the eyewitness heard a pistol shot at 10:30 in the morning. He ran to the door and saw an SS commander who demanded to see the company commander. When the latter arrived, the SS commander shouted: "On the orders of Meyer, this town is to be levelled to the ground, because this morning armed civilians attacked this locality." He then shot a 25-year-old woman who was cooking the German's lunch. According to the testimony, the Waffen-SS men killed all the inhabitants of the village and set fire to their homes.


title: Kurt Meyer

text: Separate testimony from a former SS man (given to the Western Allies' interrogators after his capture in France in 1944) substantiates elements of the story:


title: Kurt Meyer

text: The reconnaissance battalion of the LSSAH made an advance at the end of February [1943] towards the East and reached the village of Jefremowka. There they were surrounded by Russian forces. Fuel and ammo ran out and they were supplied by air until they were ordered to break through towards the West. Before trying to do so, the entire civilian population was shot and the village burnt to the ground. The battalion at that time was led by Kurt Meyer.


title: Kurt Meyer

text: Ukrainian sources, including two surviving witnesses, reported that the killings took place on 17February 1943. On 12February, LSSAH troops had occupied two villages: Yefremovka and Semyonovka. Retreating Soviet forces had wounded two SS officers. In retaliation, LSSAH troops killed 872 men, women and children five days later; about 240 were burned alive in the church in Yefremovka. Russian sources reported that the massacre was perpetrated by the "Blowtorch Battalion", led by Jochen Peiper. Meyer continued to serve in the LSSAH until the summer of 1943, when he was appointed commander of a regiment of the newly-activated, still-forming SS Division Hitlerjugend stationed in France.


title: Kurt Meyer

text: The Allies launched Operation Overlord, the amphibious invasion of France, on 6June 1944. After much confusion, SS Division Hitlerjugend got moving at about 14:30; several units advanced towards one of the beaches on which the Allies had landed, until they were halted by naval and anti-tank fire and Allied air interdiction. Meyer, confident that the Allied forces were "little fishes", ordered his regiment to counterattack. The attack led to heavy casualties. The division was ordered to break through to the beach on 7June, but Meyer instructed his regiment to take covering positions and await reinforcements. The "Canadian Official History" described Meyer's involvement in the battle:


title: Kurt Meyer

text: Although Meyer claimed later that only shortage of petrol and ammunition prevented him from carrying the attack on towards the coast, this need not be taken seriously. Indeed, he himself testified that seeing from his lofty perch "enemy movements deeper in that area"—doubtless the advance of the main body of the 9th Brigade—he came down and rode his motorcycle to the 3rd Battalion to order its C.O. "not to continue the attack north of Buron". Meyer's 2nd Battalion had been drawn into the fight, north of St. Contest "in the direction of Galmanche". Fierce fighting was going on when Meyer visited the battalion in the early evening; just as he arrived the battalion commander's head was taken off by a tank shot ... Meyer ordered both this battalion and the 1st (around Cambes) to go "over from attack to defense."


title: Kurt Meyer

text: By 22:00, Meyer had set up his command post in Ardenne Abbey. That evening, elements of the division under Meyer's command committed the Ardenne Abbey massacre; eleven Canadian prisoners of war, soldiers from the North Nova Scotia Highlanders and the 27th Armoured Regiment were shot in the back of the head.