title: Date A Live

text: Shido is recruited by Ratatoskr to make use of his mysterious ability to seal the Spirits' powers thus stopping them from being a threat to mankind. However, there is a catch: to seal a Spirit's power, he must make each Spirit fall in love with him and make her kiss him. Moreover, Shido and his companions face the opposition of the AST (Anti-Spirit Team), a special unit designed to suppress the threat posed by Spirits by eliminating them, which is backed by DEM Industries, a conglomerate led by Sir Isaac Ray Pelham Westcott who intends to exploit the powers of the Spirits for his own agenda. As Shido successfully keeps sealing more and more Spirits, he gains allies to help him with his dates with other Spirits but also increases the competition among them for his attention and affection, much to his chagrin.


title: Date A Live

text: "Date A Live" began as a light novel series written by Koushi Tachibana with illustrations by Tsunako. The first volume was published on March 19, 2011 under Fujimi Shobo's "Fujimi Fantasia Bunko". Twenty-two volumes have been released in Japan. During their panel at the 2020 Crunchyroll Expo, Yen Press announced that they have licensed the light novel.


title: Date A Live

text: The series received a total of five manga adaptions, all of which were published by Kadokawa Shoten and Fujimi Shobo in "Monthly Shōnen Ace" and "Monthly Dragon Age".


title: Date A Live

text: The anime adaptation was directed by Keitaro Motonaga and produced by AIC Plus+. The series was streamed in lower quality on Niconico, with each episode available a week before its TV premiere. The first episode was streamed on March 31 and aired on Tokyo MX on April 6, 2013. The final episode was streamed on Niconico on June 16 and aired on Tokyo MX on June 22. The opening theme is titled sung by sweet ARMS, a vocal group consisting of Iori Nomizu, Misuzu Togashi, Kaori Sadohara, and Misato. The series makes use of four ending themes: "Hatsukoi Winding Road", by Kayoko Tsumita, Risako Murai and Midori Tsukimiya; "Save The World", "Save My Heart" and , all three by Nomizu.


title: Date A Live

text: Following the TV broadcast of the final episode of the first season, a second season was announced, which was set to air in April 2014. The opening theme is sung by sweet ARMS titled "Trust in You" and the ending theme is sung by Kaori Sadohara titled "Day to Story". The animation production was held by Production IMS. An unaired episode was bundled with the third volume of the "Date A Live Encore" short story collection was released on December 9, 2014.


title: Date A Live

text: The first and second season have been licensed by Funimation for streaming and home video release in North America and by Madman Entertainment in Australia.


title: Date A Live

text: In his Twitter account, Tachibana announced "Date A Live" would get a third new anime series. Animation production was held by J.C.Staff, with the cast and staff reprising their respective roles from the previous seasons. The series aired from January 11 to March 29, 2019. The opening theme is sung by sweet ARMS titled "I Swear", and the ending theme is sung by Erii Yamazaki titled "Last Promise". The third season ran for 12 episodes. Crunchyroll simulcast the third season, while Funimation produced a simuldub. In Australia and New Zealand, AnimeLab simulcast the third season.


title: Date A Live

text: On September 17, 2019, a new anime project was announced. It was later announced to be an anime adaptation of the "" spin-off novels. Tachibana announced via his Twitter account that apart from the spin-off adaptation, the main series would get a new anime as well.


title: Date A Live

text: On March 16, 2020, it was announced that the series would get a fourth season. The season is produced by Geek Toys and was scheduled to premiere in October 2021, but was delayed to 2022 for "various reasons". Jun Nakagawa directed the fourth season, with Fumihiko Shimo writing the series' scripts, Naoto Nakamura designing the characters, and Go Sakabe returning to compose the series' music. It aired from April 8 to June 24, 2022. The opening theme is sung by Miyu Tomita titled "OveR" and the ending theme is sung by sweet ARMS titled "S.O.S".


title: Date A Live

text: Following Sony's acquisition of Crunchyroll, the series was moved from Funimation to Crunchyroll. On April 21, 2022, Crunchyroll announced that the season would receive an English dub, which premiered the following day.


title: Date A Live

text: An animated theatrical film was announced via the official Twitter account of the television series as the airing of the second television season concluded. On the event of "Date A Live II", the staff unveiled that the film will be titled as "" and premiered on August 22, 2015, with an original story supervised by the original light novel author, Koushi Tachibana. Nobunaga Shimazaki, the voice actor of Shido Itsuka, introduced a silhouette of the new title character, named . During the events of "Tohka's Birthday" on 10 April, Sora Amamiya was confirmed to be voicing Mayuri.


title: Date A Live

text: A video game named produced by Compile Heart and Sting Entertainment released on June 27, 2013 for the PlayStation 3. A promotional video was shown at Anime Contents Expo 2013. The game features a new original character named , voiced by Kana Hanazawa. A PlayStation Vita version of the game was released in on July 30, 2015, and features new characters and scenarios.


title: Date A Live

text: Another video game, titled , was released in June 26, 2014 for the PlayStation 3, featuring another new character named , voiced by Suzuko Mimori. A new installment for both past games, named produced by Compile Heart and Sting Entertainment was released on July 30, 2015 for the PlayStation Vita. It is a de facto sequel with new characters and new scenarios. The game features the Yamai Sisters, Miku Izayoi, Rinne Sonogami, Maria Arusu, as well as Marina Arusu, and a new original character named , voiced by Ayane Sakura. A promotional video was shown at the events of Date A Fes II. An English version of "Date A Live: Rio Reincarnation" has been released on PlayStation 4 and Steam platforms on July 23, 2019. The PlayStation 4 version was censored, which caused criticism.


title: Date A Live

text: A fourth video game produced again by Compile Heart, titled , was scheduled to be released on July 18, 2019 for the PlayStation 4, in Japan. In addition to the standard addition, which will cost 7,776 yen at retail and yen via download, a 9,936 yen limited edition is also planned. The limited edition includes a Tsunako-designed box, special books (Koushi Tachibana-written short story, etc.), and a drama CD. Due to various reasons, the release date has been pushed back to September 24, 2020.


title: Date A Live

text: A free-to-play mobile game titled "Date A Live: Spirit Pledge" was released in China on September 21, 2018 for Android and iOS. A beta test of a global version started on July 26, 2020.


title: Date A Live

text: The first volume of the first anime season placed eighth place amongst Blu-ray sales in Japan during its debut week within the Oricon charts. The PS3 game "Date A Live: Rinne Utopia" sold 23,340 physical retail copies within the first week of release in Japan. By October 2015, the series as a whole had sold over four million copies.


title: Date A Live

text: On June 12, 2015, the Chinese Ministry of Culture listed "Date A Live II" among 38 anime and manga titles banned in China.


title: CE marking

text: On commercial products, the letters CE (as the logo ) mean that the manufacturer or importer affirms the good's conformity with European health, safety, and environmental protection standards. It is not a quality indicator or a certification mark. The CE marking is required for goods sold in the European Economic Area (EEA), but is also found on products sold elsewhere that have been manufactured to EEA standards.


title: CE marking

text: The mark indicates that the product may be traded freely in any part of the European Economic Area, regardless of its country of origin. It consists of the CE logo and, if applicable, the four digit identification number of the notified body involved in the conformity assessment procedure. "CE" is the abbreviation of (French for "European conformity").


title: CE marking

text: The mark on a product indicates that the manufacturer or importer of that product affirms its compliance with the relevant EU legislation and the product may be sold anywhere in the European Economic Area (EEA). It is a criminal offence to affix a mark to a product that is not compliant or offer it for sale.


title: CE marking

text: For example, most electrical products must comply with the Low Voltage Directive and the EMC Directive, among others; toys must comply with the Toy Safety Directive. (The Low Voltage Directive is about electrical safety; EMC or Electromagnetic Compatibility means the device will work as intended without interfering with, or being affected by, the use or function of any other device.) The mark indicates compliance with as many norms (directives and regulations) as apply at the time of the declaration of compliance (see below). In the case of electrical products, several later norms such as the Restriction of Hazardous Substances Directive (RoHS) and Waste Electrical and Electronic Equipment Directive (WEEE) are relevant in addition to the Low Voltage Directive and EMC Directive. The exact significance of the mark therefore depends on when it was applied to a specific unit.


title: CE marking

text: The marking does not indicate EEA manufacture or that the EU or another authority has approved a product as safe or conformant. The EU requirements may include safety, health, and environmental protection. If stipulated in any EU product legislation, assessment by a Notified Body or manufacture according to a certified production quality system may be required. Where relevant, the mark is followed by the registration number of the notified body involved in conformity assessment.


title: CE marking

text: Not all products need CE marking to be traded in the EEA; only product categories subject to relevant directives or regulations are required (and allowed) to bear CE marking. Most CE-marked products can be placed on the market subject only to an internal production control by the manufacturer (Module A; see Self-certification, below), with no independent check of the conformity of the product with EU legislation; ANEC has cautioned that, amongst other things, CE marking cannot be considered a "safety mark" for consumers.


title: CE marking

text: CE marking is mandatory for certain product groups intended for sale within the European Union, the European Free Trade Association (EFTA), and Turkey. The manufacturers of products made within these countries, and the importers of goods made in other countries, affirm that CE-marked goods conform to EU standards. Following Brexit, the UK government introduced UKCA marking as its equivalent conformance indicator and this is required for relevant goods to be sold in Great Britain although goods with the mark (only) can still be used until 31 December 2024. As Northern Ireland has remained aligned to the European Single Market under the Northern Ireland Protocol, CE marking remains mandatory for products placed on the market there; although the UKCA mark may be used in addition it is not required. Goods for sale anywhere in the United Kingdom may (and typically will) carry both marks.


title: CE marking

text: , CE marking was not required by countries of the Central European Free Trade Agreement (CEFTA), but members Albania, North Macedonia, Serbia, and Montenegro have applied for membership of the European Union, and are adopting many of its standards within their legislation (as had most Central European former member countries of CEFTA that joined the EU, before joining).


title: CE marking

text: The formal legal status of the mark is set out in various EU Directives and Regulations. The underlying principles are explained in the Commission's "Blue Guide".


title: CE marking

text: Responsibility for CE marking lies with whoever puts the product on the market in the EU, i.e. an EU-based manufacturer, the importer or distributor of a product made outside the EU, or an EU-based office of a non-EU manufacturer.


title: CE marking

text: The manufacturer of a product affixes the CE marking to it but has to take certain obligatory steps before the product can bear CE marking. The manufacturer must carry out a conformity assessment, set up a technical file, and sign a Declaration stipulated by the leading legislation for the product. The documentation has to be made available to authorities on request.


title: CE marking

text: Importers of products have to verify that the manufacturer outside the EU has undertaken the necessary steps and that the documentation is available upon request. Importers should also make sure that contact with the manufacturer can always be established.


title: CE marking

text: Distributors must be able to demonstrate to national authorities that they have acted with due care and they must have affirmation from the manufacturer or importer that the necessary measures have been taken.


title: CE marking

text: If importers or distributors market the products under their own name, they take over the manufacturer's responsibilities. In this case they must have sufficient information on the design and production of the product, as they will be assuming the legal responsibility when they affix the CE marking.


title: CE marking

text: Since achieving compliance can be very complex, CE-marking conformity assessment, provided by a notified body, is of great importance throughout the entire CE-marking process, from design verification, and set up of the technical file to the EU declaration of conformity.


title: CE marking

text: A guide to the implementation of directives and regulations based on the New Approach and the Global Approach (the "Blue Guide") was first published by the European Union in 2000. Updated versions were published on 28 February 2014 and 26 July 2016.


title: CE marking

text: Depending on the level of risk of the product, the CE marking is affixed to a product by the manufacturer or authorized representative who needs to ensure that the product meets all the CE marking requirements. In some cases, if a product has minimal risk, it can be self-certified by a manufacturer making a declaration of conformity and affixing the CE marking to their own product. Self-certification exists only for products that have a minimal risk for their use, and this is clearly foreseen in the relevant directive and regulation according to the product "category". In order to certify, the manufacturer must do several things:


title: CE marking

text: The level of risk is defined by the "category" of each equipment. The higher the category, the higher the risk. After defining the category, the manufacturer, in order to obtain certification, shall then apply the relevant procedures for the specific category of the product or choose the relevant procedures for a higher-category product. The manufacturer, after insuring that the relevant modules for the product category have been applied, will affix the mark and draw up a Declaration of Conformity. The Declaration of Conformity contains a description of the product, the directive(s) and regulation(s) applied, the product category for each directive or regulation, the module chosen, and the name and registration number of the notified body involved in certification procedures (models).


title: CE marking

text: Notified bodies involved in certification procedures are organizations that have been nominated by a member state (according to an accreditation procedure) and have been notified by the European Commission. These notified bodies act as Independent Inspection organizations and carry out the procedures as listed in the relevant Modules applied as stated by the relevant directives and regulations. A manufacturer can choose any notified body (notified for the certain directive or regulation and relevant Modules) in any Member State of the European Union.


title: CE marking

text: The first step is to identify whether the product needs to bear CE marking or not. Not all products are required to bear CE marking, only the products that fall within the scope of at least one of the sectoral norms (directives and regulations) requiring CE marking. There are more than 20 sectoral product norms requiring CE marking covering, but not limited to, products such as electrical equipment, machines, medical devices, toys, pressure equipment, PPE, wireless devices and construction products.


title: CE marking

text: Identifying which norm(s) may be applicable, as there may be more than one, involves a simple exercise of reading the scope of each norm to establish which apply to the product (Such as the "Low Voltage Directive," 2014/35/EU). If the product does not fall within the scope of any of the sectoral norm, then the product does not need to bear CE marking (and, indeed, must not bear CE marking).


title: CE marking

text: Each norm has slightly different methods of demonstrating conformity depending on the classification of the product and its intended use. Every Directive or Regulation has a number of 'essential requirements' that the product has to meet before being placed on the market.


title: CE marking

text: The best way to demonstrate that these essential requirements have been met is by meeting the requirements of an applicable 'harmonised standard,’ which offer a presumption of conformity to the essential requirements, although the use of standards usually remains voluntary. Harmonised standards can be identified by searching the 'Official Journal' on the European Commission's website, or by visiting the New Approach website established by the European Commission and EFTA with the European Standardisation Organisations.


title: CE marking

text: The process is not always a self-declaration process, there are various 'attestation routes' to conformity depending on the Directive or Regulation and classification of the product. Many products (such as invasive medical devices, or fire alarm and extinguisher systems, Pressure Equipment, Lifts etc.) in most cases, have a mandatory requirement for the involvement of an authorised third party e.g. a "notified body".


title: CE marking

text: When all of the requirements have been established, the conformity of the product to the essential requirements of the norm(s) needs to be assessed. This usually involves assessment and/or testing, and may include an evaluation of the conformity of the product to the harmonised standard(s) identified in step 2.


title: CE marking

text: Technical documentation, usually referred to as the technical file, relating to the product or range of products needs to be compiled. This information should cover every aspect relating to conformity and is likely to include details of the design, development and manufacture of the product.


title: CE marking

text: When the manufacturer, importer or authorised representative is satisfied that their product conforms to the applicable norms, an EU declaration of conformity must be completed or, for partly completed machinery under the Machinery Directive, an ECU declaration of incorporation.


title: CE marking

text: The EU declaration of conformity must include: manufacturer's details (name and address, etc.); essential characteristics the product complies; any European standards and performance data; if relevant the identification number of the notified body; and a legally binding signature on behalf of the organization.


title: CE marking

text: There are numerous 'Agreements on Mutual Recognition of Conformity Assessment' between the European Union and other countries such as the US, Japan, Canada, Australia, New Zealand and Israel. Consequently, CE marking is now found on many products from these countries. Japan has its own marking known as the Conformity Mark.


title: CE marking

text: Switzerland and Turkey (which are not members of the EEA) also require products to bear CE marking as an affirmation of conformity.


title: CE marking

text: When the manufacturer of a machine puts the CE marking, it engages itself and guarantees, that it makes all the tests, assessments and evaluation on the product to conform to all the requirements of "all" the norms that apply to its product.


title: CE marking

text: The European Commission is aware that CE markings, like other certifications marks, are misused. CE marking is sometimes affixed to products that do not fulfill the legal requirements and conditions, or it is affixed to products for which it is not required. In one case it was reported that "Chinese manufacturers were submitting well-engineered electrical products to obtain conformity testing reports, but then removing non-essential components in production to reduce costs". A test of 27 electrical chargers with UK sockets in 2008 found that all the eight legitimately branded ones with a reputable name met safety standards, but none of those unbranded or with minor names did, despite bearing the mark; non-compliant devices were actually potentially unreliable and dangerous, presenting electrical and fire hazards.


title: CE marking

text: There are also cases in which the product complies with the applicable requirements, but the form, dimensions, or proportions of the mark itself are not as specified in the legislation.


title: CE marking

text: In 2008, a logo very similar to CE marking was alleged to exist and to stand for "China Export" because some Chinese manufacturers apply it to their products. However, the European Commission says that this is a misconception. The matter was raised at the European Parliament in 2008. The Commission responded that it was unaware of the existence of any "Chinese Export" mark and that, in its view, the misunderstanding had arisen because a producer had failed to respect the precise dimensions and proportions of the mark as prescribed in the legislation. The Commission was also aware of fraudulent misuse of the mark on products that did not comply with the standards, but that this is a separate issue. It had initiated the procedure to register CE marking as a Community collective trademark, and was in discussion with Chinese authorities to ensure compliance with European legislation. Chinese (and other non-EU) manufacturers are permitted to use the mark provided that the goods have been manufactured in accordance with the relevant EU directives and regulations.


title: CE marking

text: Nevertheless, and despite the Commission's assurance that it is without foundation, this urban myth continues to be available on many websites.


title: CE marking

text: Directive 2006/95/EC, the "Low Voltage" Directive, specifically excludes (amongst other things) "plugs and socket outlets for domestic use" which are not covered by any Union norm and therefore must not be CE marked. Throughout the EU, as in other jurisdictions, the control of "plugs and socket outlets for domestic use" is subject to national regulations. Despite this, the illegal use of CE marking can be found on domestic plugs and sockets, particularly so-called "universal sockets".


title: CE marking

text: It is fairly common to see domestic sockets (and adaptors) that have an inbuilt 5 volt power supply. In the case of these sockets they must be CE marked, but the mark applies to the 5 volt converter "only" and not the rest of the socket or adaptor. This is comparable to dedicated 5 volt power supplies.


title: CE marking

text: There are mechanisms in place to ensure that the CE marking is put on products correctly. Controlling products bearing CE marking is the responsibility of public authorities in member states, in cooperation with the European Commission. Citizens may contact national market surveillance authorities if the misuse of the CE marking is suspected or if a product's safety is questioned.


title: CE marking

text: In the UK, sale of any product that carries a mark that is not so approved, or outside the scope of approval is a specific offence under Section 1 of the Trade Descriptions Act 1968. The seller of such an article is as equally guilty as the manufacturer or importer. Ignorance as to the true status of the sold item is no defence against a prosecution (strict liability). Under the Act, the misrepresentation is that the sold item conforms to a specification that it does not or that there is no such specification to which it can conform.


title: CE marking

text: The procedures, measures and sanctions applying to counterfeiting of the CE marking vary according to the respective member state's national administrative and penal legislation. Depending on the seriousness of the crime, economic operators may be liable to a fine and, in some circumstances, imprisonment. However, if the product is not regarded as an imminent safety risk, the manufacturer may be given an opportunity to ensure that the product is in conformity with the applicable legislation before being forced to take the product off the market.


title: CE marking

text: , the mark does not have a Unicode code point, nor is one in prospect. According to the Unicode principles, the mark is a font choice for the two ordinary upper-case letters, C and E, with a specific kerning arrangement. The exact geometry that constitutes the mark is provided in the vector graphics data of the .ai and .eps files available from the European Commission.


title: CE marking

text: On motor vehicles and related parts, the United Nations Economic Commission for Europe's (UNECE) type approval can overrule some EU legislation, so the "emark" or "Emark", is often seen instead of the CE logo. Unlike the CE logo, the UNECE marks are not self-certified. This mark is not to be confused with the European Union's estimated sign, .


title: Mackerel

text: Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment.


title: Mackerel

text: Mackerel species typically have deeply forked tails and vertical 'tiger-like' stripes on their backs with an iridescent green-blue quality. Many are restricted in their distribution ranges and live in separate populations or fish stocks based on geography. Some stocks migrate in large schools along the coast to suitable spawning grounds, where they spawn in fairly shallow waters. After spawning they return the way they came in smaller schools to suitable feeding grounds, often near an area of upwelling. From there they may move offshore into deeper waters and spend the winter in relative inactivity. Other stocks migrate across oceans.


title: Mackerel

text: Smaller mackerel are forage fish for larger predators, including larger mackerel and Atlantic cod. Flocks of seabirds, whales, dolphins, sharks, and schools of larger fish such as tuna and marlin follow mackerel schools and attack them in sophisticated and cooperative ways. Mackerel flesh is high in omega-3 oils and is intensively harvested by humans. In 2009, over 5 million tons were landed by commercial fishermen. Sport fishermen value the fighting abilities of the king mackerel.


title: Mackerel

text: Over 30 different species, principally belonging to the family Scombridae, are commonly referred to as mackerel. The term "mackerel" is derived from Old French and may have originally meant either "marked, spotted" or "pimp, procurer". The latter connection is not altogether clear, but mackerel spawn enthusiastically in shoals near the coast, and medieval ideas on animal procreation were creative.


title: Mackerel

text: About 21 species in the family Scombridae are commonly called mackerel. The type species for the scombroid mackerel is the Atlantic mackerel, "Scomber scombrus". Until recently, Atlantic chub mackerel and Indo-Pacific chub mackerel were thought to be subspecies of the same species. In 1999, Collette established, on molecular and morphological considerations, that these are separate species. Mackerel are smaller with shorter lifecycles than their close relatives, the tuna, which are also members of the same family.


title: Mackerel

text: The true mackerels belong to the tribe Scombrini. The tribe consists of seven species, each belonging to one of two genera: "Scomber" or "Rastrelliger".


title: Mackerel

text: The Spanish mackerels belong to the tribe Scomberomorini, which is the "cousin tribe" of the true mackerels. This tribe consists of 21 species in all—18 of those are classified into the genus "Scomberomorus", two into "Grammatorcynus", and a single species into the monotypic genus "Acanthocybium".


title: Mackerel

text: In addition, a number of species with mackerel-like characteristics in the families Carangidae, Hexagrammidae and Gempylidae are commonly referred to as mackerel. Some confusion had occurred between the Pacific jack mackerel ("Trachurus symmetricus") and the heavily harvested Chilean jack mackerel ("T. murphyi"). These have been thought at times to be the same species, but are now recognised as separate species.


title: Mackerel

text: The term "mackerel" is also used as a modifier in the common names of other fish, sometimes indicating the fish has vertical stripes similar to a scombroid mackerel:


title: Mackerel

text: By extension, the term is applied also to other species such as the mackerel tabby cat, and to inanimate objects such as the altocumulus mackerel sky cloud formation.


title: Mackerel

text: Most mackerel belong to the family Scombridae, which also includes tuna and bonito. Generally, mackerel are much smaller and slimmer than tuna, though in other respects, they share many common characteristics. Their scales, if present at all, are extremely small. Like tuna and bonito, mackerel are voracious feeders, and are swift and manoeuvrable swimmers, able to streamline themselves by retracting their fins into grooves on their bodies. Like other scombroids, their bodies are cylindrical with numerous finlets on the dorsal and ventral sides behind the dorsal and anal fins, but unlike the deep-bodied tuna, they are slim.


title: Mackerel

text: The type species for scombroid mackerels is the Atlantic mackerel, "Scomber scombrus". These fish are iridescent blue-green above with a silvery underbelly and near-vertical wavy black stripes running along their upper bodies.


title: Mackerel

text: The prominent stripes on the back of mackerels seemingly are there to provide camouflage against broken backgrounds. That is not the case, though, because mackerel live in midwater pelagic environments which have no background. However, fish have an optokinetic reflex in their visual systems that can be sensitive to moving stripes. For fish to school efficiently, they need feedback mechanisms that help them align themselves with adjacent fish, and match their speed. The stripes on neighbouring fish provide "schooling marks", which signal changes in relative position.


title: Mackerel

text: A layer of thin, reflecting platelets is seen on some of the mackerel stripes. In 1998, E J Denton and D M Rowe argued that these platelets transmit additional information to other fish about how a given fish moves. As the orientation of the fish changes relative to another fish, the amount of light reflected to the second fish by this layer also changes. This sensitivity to orientation gives the mackerel "considerable advantages in being able to react quickly while schooling and feeding."


title: Mackerel

text: Mackerel range in size from small forage fish to larger game fish. Coastal mackerel tend to be small. The king mackerel is an example of a larger mackerel. Most fish are cold-blooded, but exceptions exist. Certain species of fish maintain elevated body temperatures. Endothermic bony fishes are all in the suborder Scombroidei and include the butterfly mackerel, a species of primitive mackerel.


title: Mackerel

text: Mackerel are strong swimmers. Known in the latin family as "punctualis piscis" which translates to "punctual fish." This is due to its punctuality of migration during mating season as it moves from warm to cold waters. Atlantic mackerel can swim at a sustained speed of 0.98 m/sec with a burst speed of 5.5 m/sec, while chub mackerel can swim at a sustained speed of 0.92 m/sec with a burst speed of 2.25 m/sec.


title: Mackerel

text: Three species of jack mackerels are found in coastal waters around New Zealand: the Australasian, Chilean, and Pacific jack mackerels. They are mainly captured using purse seine nets, and are managed as a single stock that includes multiple species.


title: Mackerel

text: Some mackerel species migrate vertically. Adult snake mackerel conduct a diel vertical migration, staying in deeper water during the day and rising to the surface at night to feed. The young and juveniles also migrate vertically, but in the opposite direction, staying near the surface during the day and moving deeper at night. This species feeds on squid, pelagic crustaceans, lanternfishes, flying fishes, sauries, and other mackerel. It is, in turn, preyed upon by tuna and marlin.


title: Mackerel

text: Mackerel are prolific broadcast spawners, and must breed near the surface of the water because the eggs of the females float. Individual females lay between 300,000 and 1,500,000 eggs. Their eggs and larvae are pelagic, that is, they float free in the open sea. The larvae and juvenile mackerel feed on zooplankton. As adults, they have sharp teeth, and hunt small crustaceans such as copepods, forage fish, shrimp, and squid. In turn, they are hunted by larger pelagic animals such as tuna, billfish, sea lions, sharks, and pelicans.


title: Mackerel

text: Off Madagascar, spinner sharks follow migrating schools of mackerel. Bryde's whales feed on mackerel when they can find them. They use several feeding methods, including skimming the surface, lunging, and bubble nets.


title: Mackerel

text: Chub mackerel, "Scomber japonicus", are the most intensively fished scombroid mackerel. They account for about half the total capture production of scombroid mackerels. As a species, they are easily confused with Atlantic mackerel. Chub mackerel migrate long distances in oceans and across the Mediterranean. They can be caught with drift nets and suitable trawls, but are most usually caught with surround nets at night by attracting them with lampara lamps.


title: Mackerel

text: The remaining catch of scombroid mackerels is divided equally between the Atlantic mackerel and all other scombroid mackerels.


title: Mackerel

text: Just these two species (Chub mackerel and Atlantic mackerel) account for about 75% of the total catch of scombroid mackerels.


title: Mackerel

text: Chilean jack mackerel are the most commonly fished nonscombroid mackerel, fished as heavily as chub mackerel. The species has been overfished, and its fishery may now be in danger of collapsing.


title: Mackerel

text: Smaller mackerel behave like herrings, and are captured in similar ways. Fish species like these, which school near the surface, can be caught efficiently by purse seining. Huge purse-seine vessels use spotter planes to locate the schooling fish. Then they close in using sophisticated sonar to track the shape of the school, which is then encircled with fast auxiliary boats that deploy purse seines as they speed around the school.


title: Mackerel

text: Suitably designed trollers can also catch mackerels effectively when they swim near the surface. Trollers typically have several long booms which they lift and drop with "topping lifts". They haul their lines with electric or hydraulic reels. Fish aggregating devices are also used to target mackerel.


title: Mackerel

text: The North Sea has been overfished to the point where the ecological balance has become disrupted and many jobs in the fishing industry have been lost.


title: Mackerel

text: The Southeast US region spans the Gulf of Mexico, the Caribbean Sea, and the US Southeast Atlantic. Overfishing of king and Spanish mackerel occurred in the 1980s. Regulations were introduced to restrict the size, fishing locations, and bag limits for recreational fishers and commercial fishers. Gillnets were banned in waters off Florida. By 2001, the mackerel stocks had bounced back.


title: Mackerel

text: Mackerel is an important food fish that is consumed worldwide. As an oily fish, it is a rich source of omega-3 fatty acids. The flesh of mackerel spoils quickly, especially in the tropics, and can cause scombroid food poisoning. Accordingly, it should be eaten on the day of capture, unless properly refrigerated or cured.


title: Mackerel

text: Mackerel preservation is not simple. Before the 19th-century development of canning and the widespread availability of refrigeration, salting and smoking were the principal preservation methods available. Historically in England, this fish was not preserved, but was consumed only in its fresh form. However, spoilage was common, leading the authors of "The Cambridge Economic History of Europe" to remark: "There are more references to stinking mackerel in English literature than to any other fish!" In France, mackerel was traditionally pickled with large amounts of salt, which allowed it to be sold widely across the country.


title: Mackerel

text: For many years mackerel was regarded as 'unclean' in the UK and other places due to folklore which suggested that the fish fed on the corpses of dead sailors. A 1976 survey of housewives in Britain undertaken by the White Fish Authority indicated a reluctance to departing from buying the traditional staples of cod, haddock or salmon. Less than 10% of the surveys 1,931 respondents had ever bought mackerel and only 3% did so regularly. As a result of this trend many UK fishmongers during the 1970s did not display or even stock mackerel.


title: Cache (computing)

text: In computing, a cache ( ) is a hardware or software component that stores data so that future requests for that data can be served faster; the data stored in a cache might be the result of an earlier computation or a copy of data stored elsewhere. A "cache hit" occurs when the requested data can be found in a cache, while a "cache miss" occurs when it cannot. Cache hits are served by reading data from the cache, which is faster than recomputing a result or reading from a slower data store; thus, the more requests that can be served from the cache, the faster the system performs.


title: Cache (computing)

text: To be cost-effective and to enable efficient use of data, caches must be relatively small. Nevertheless, caches have proven themselves in many areas of computing, because typical computer applications access data with a high degree of locality of reference. Such access patterns exhibit temporal locality, where data is requested that has been recently requested already, and spatial locality, where data is requested that is stored physically close to data that has already been requested.


title: Cache (computing)

text: There is an inherent trade-off between size and speed (given that a larger resource implies greater physical distances) but also a tradeoff between expensive, premium technologies (such as SRAM) vs cheaper, easily mass-produced commodities (such as DRAM or hard disks).


title: Cache (computing)

text: A larger resource incurs a significant latency for access e.g. it can take hundreds of clock cycles for a modern 4 GHz processor to reach DRAM. This is mitigated by reading in large chunks, in the hope that subsequent reads will be from nearby locations. Prediction or explicit prefetching might also guess where future reads will come from and make requests ahead of time; if done correctly the latency is bypassed altogether.


title: Cache (computing)

text: The use of a cache also allows for higher throughput from the underlying resource, by assembling multiple fine grain transfers into larger, more efficient requests. In the case of DRAM circuits, this might be served by having a wider data bus. For example, consider a program accessing bytes in a 32-bit address space, but being served by a 128-bit off-chip data bus; individual uncached byte accesses would allow only 1/16th of the total bandwidth to be used, and 80% of the data movement would be memory addresses instead of data itself. Reading larger chunks reduces the fraction of bandwidth required for transmitting address information.


title: Cache (computing)

text: Hardware implements cache as a block of memory for temporary storage of data likely to be used again. Central processing units (CPUs), solid-state drives (SSDs) and hard disk drives (HDDs) frequently include hardware-based cache, while web browsers and web servers commonly rely on software caching.


title: Cache (computing)

text: A cache is made up of a pool of entries. Each entry has associated "data", which is a copy of the same data in some "backing store". Each entry also has a "tag", which specifies the identity of the data in the backing store of which the entry is a copy. Tagging allows simultaneous cache-oriented algorithms to function in multilayered fashion without differential relay interference.


title: Cache (computing)

text: When the cache client (a CPU, web browser, operating system) needs to access data presumed to exist in the backing store, it first checks the cache. If an entry can be found with a tag matching that of the desired data, the data in the entry is used instead. This situation is known as a cache hit. For example, a web browser program might check its local cache on disk to see if it has a local copy of the contents of a web page at a particular URL. In this example, the URL is the tag, and the content of the web page is the data. The percentage of accesses that result in cache hits is known as the hit rate or hit ratio of the cache.


title: Cache (computing)

text: The alternative situation, when the cache is checked and found not to contain any entry with the desired tag, is known as a cache miss. This requires a more expensive access of data from the backing store. Once the requested data is retrieved, it is typically copied into the cache, ready for the next access.


title: Cache (computing)

text: During a cache miss, some other previously existing cache entry is removed in order to make room for the newly retrieved data. The heuristic used to select the entry to replace is known as the replacement policy. One popular replacement policy, "least recently used" (LRU), replaces the oldest entry, the entry that was accessed less recently than any other entry (see cache algorithm). More efficient caching algorithms compute the use-hit frequency against the size of the stored contents, as well as the latencies and throughputs for both the cache and the backing store. This works well for larger amounts of data, longer latencies, and slower throughputs, such as that experienced with hard drives and networks, but is not efficient for use within a CPU cache.


title: Cache (computing)

text: When a system writes data to cache, it must at some point write that data to the backing store as well. The timing of this write is controlled by what is known as the "write policy". There are two basic writing approaches:


title: Cache (computing)

text: A write-back cache is more complex to implement, since it needs to track which of its locations have been written over, and mark them as "dirty" for later writing to the backing store. The data in these locations are written back to the backing store only when they are evicted from the cache, an effect referred to as a "lazy write". For this reason, a read miss in a write-back cache (which requires a block to be replaced by another) will often require two memory accesses to service: one to write the replaced data from the cache back to the store, and then one to retrieve the needed data.


title: Cache (computing)

text: Other policies may also trigger data write-back. The client may make many changes to data in the cache, and then explicitly notify the cache to write back the data.


title: Cache (computing)

text: Since no data is returned to the requester on write operations, a decision needs to be made on write misses, whether or not data would be loaded into the cache.


title: Cache (computing)

text: Both write-through and write-back policies can use either of these write-miss policies, but usually they are paired in this way:


title: Cache (computing)

text: Entities other than the cache may change the data in the backing store, in which case the copy in the cache may become out-of-date or "stale". Alternatively, when the client updates the data in the cache, copies of those data in other caches will become stale. Communication protocols between the cache managers which keep the data consistent are known as coherency protocols.


title: Cache (computing)

text: For example, demand-paging virtual memory reads one page of virtual memory (often 4 kBytes) from disk into the disk cache in RAM.


title: Cache (computing)

text: For example, a typical CPU reads a single L2 cache line of 128 bytes from DRAM into the L2 cache, and a single L1 cache line of 64 bytes from the L2 cache into the L1 cache.


title: Cache (computing)

text: go further—they not only read the chunk requested, but guess that the next chunk or two will soon be required, and so prefetch that data into the cache ahead of time.


title: Cache (computing)

text: when the backing store has a long latency to read the first chunk and much shorter times to sequentially read the next few chunks, such as disk storage and DRAM.


title: Cache (computing)

text: A few operating systems go further with a loader that always pre-loads the entire executable into RAM.


title: Cache (computing)

text: A few caches go even further, not only pre-loading an entire file, but also starting to load other related files that may soon be requested, such as the page cache associated with a prefetcher or the web cache associated with link prefetching.


title: Cache (computing)

text: Small memories on or close to the CPU can operate faster than the much larger main memory. Most CPUs since the 1980s have used one or more caches, sometimes in cascaded levels; modern high-end embedded, desktop and server microprocessors may have as many as six types of cache (between levels and functions). Examples of caches with a specific function are the D-cache and I-cache and the translation lookaside buffer for the MMU.


title: Cache (computing)

text: Earlier graphics processing units (GPUs) often had limited read-only texture caches, and introduced Morton order swizzled textures to improve 2D cache coherency. Cache misses would drastically affect performance, e.g. if mipmapping was not used. Caching was important to leverage 32-bit (and wider) transfers for texture data that was often as little as 4 bits per pixel, indexed in complex patterns by arbitrary UV coordinates and perspective transformations in inverse texture mapping.


title: Cache (computing)

text: As GPUs advanced (especially with GPGPU compute shaders) they have developed progressively larger and increasingly general caches, including instruction caches for shaders, exhibiting increasingly common functionality with CPU caches. For example, GT200 architecture GPUs did not feature an L2 cache, while the Fermi GPU has 768 KB of last-level cache, the Kepler GPU has 1536 KB of last-level cache, and the Maxwell GPU has 2048 KB of last-level cache. These caches have grown to handle synchronisation primitives between threads and atomic operations, and interface with a CPU-style MMU.


title: Cache (computing)

text: Digital signal processors have similarly generalised over the years. Earlier designs used scratchpad memory fed by DMA, but modern DSPs such as Qualcomm Hexagon often include a very similar set of caches to a CPU (e.g. Modified Harvard architecture with shared L2, split L1 I-cache and D-cache).


title: Cache (computing)

text: A memory management unit (MMU) that fetches page table entries from main memory has a specialized cache, used for recording the results of virtual address to physical address translations. This specialized cache is called a translation lookaside buffer (TLB).


title: Cache (computing)

text: Information-centric networking (ICN) is an approach to evolve the Internet infrastructure away from a host-centric paradigm, based on perpetual connectivity and the end-to-end principle, to a network architecture in which the focal point is identified information (or content or data). Due to the inherent caching capability of the nodes in an ICN, it can be viewed as a loosely connected network of caches, which has unique requirements of caching policies. However, ubiquitous content caching introduces the challenge to content protection against unauthorized access, which requires extra care and solutions.


title: Cache (computing)

text: Unlike proxy servers, in ICN the cache is a network-level solution. Therefore, it has rapidly changing cache states and higher request arrival rates; moreover, smaller cache sizes further impose a different kind of requirements on the content eviction policies. In particular, eviction policies for ICN should be fast and lightweight. Various cache replication and eviction schemes for different ICN architectures and applications have been proposed.


title: Cache (computing)

text: The Time aware Least Recently Used (TLRU) is a variant of LRU designed for the situation where the stored contents in cache have a valid life time. The algorithm is suitable in network cache applications, such as Information-centric networking (ICN), Content Delivery Networks (CDNs) and distributed networks in general. TLRU introduces a new term: TTU (Time to Use). TTU is a time stamp of a content/page which stipulates the usability time for the content based on the locality of the content and the content publisher announcement. Owing to this locality based time stamp, TTU provides more control to the local administrator to regulate in network storage.


title: Cache (computing)

text: In the TLRU algorithm, when a piece of content arrives, a cache node calculates the local TTU value based on the TTU value assigned by the content publisher. The local TTU value is calculated by using a locally defined function. Once the local TTU value is calculated the replacement of content is performed on a subset of the total content stored in cache node. The TLRU ensures that less popular and small life content should be replaced with the incoming content.


title: Cache (computing)

text: The Least Frequent Recently Used (LFRU) cache replacement scheme combines the benefits of LFU and LRU schemes. LFRU is suitable for 'in network' cache applications, such as Information-centric networking (ICN), Content Delivery Networks (CDNs) and distributed networks in general. In LFRU, the cache is divided into two partitions called privileged and unprivileged partitions. The privileged partition can be defined as a protected partition. If content is highly popular, it is pushed into the privileged partition. Replacement of the privileged partition is done as follows: LFRU evicts content from the unprivileged partition, pushes content from privileged partition to unprivileged partition, and finally inserts new content into the privileged partition. In the above procedure the LRU is used for the privileged partition and an approximated LFU (ALFU) scheme is used for the unprivileged partition, hence the abbreviation LFRU.


title: Cache (computing)

text: The basic idea is to filter out the locally popular contents with ALFU scheme and push the popular contents to one of the privileged partition.


title: Cache (computing)

text: Back in 2010 "The New York Times" suggested "Type 'weather' followed by your zip code." By 2011, the use of smartphones with weather forecasting options was overly taxing AccuWeather servers; two requests within the same park would generate separate requests. An optimization by edge-servers to truncate the GPS coordinates to fewer decimal places meant that the cached results from the earlier query would be used. The number of to-the-server lookups per day dropped by half.


title: Cache (computing)

text: While CPU caches are generally managed entirely by hardware, a variety of software manages other caches. The page cache in main memory, which is an example of disk cache, is managed by the operating system kernel.


title: Cache (computing)

text: While the disk buffer, which is an integrated part of the hard disk drive or solid state drive, is sometimes misleadingly referred to as "disk cache", its main functions are write sequencing and read prefetching. Repeated cache hits are relatively rare, due to the small size of the buffer in comparison to the drive's capacity. However, high-end disk controllers often have their own on-board cache of the hard disk drive's data blocks.


title: Cache (computing)

text: Finally, a fast local hard disk drive can also cache information held on even slower data storage devices, such as remote servers (web cache) or local tape drives or optical jukeboxes; such a scheme is the main concept of hierarchical storage management. Also, fast flash-based solid-state drives (SSDs) can be used as caches for slower rotational-media hard disk drives, working together as hybrid drives or solid-state hybrid drives (SSHDs).


title: Cache (computing)

text: Web browsers and web proxy servers employ web caches to store previous responses from web servers, such as web pages and images. Web caches reduce the amount of information that needs to be transmitted across the network, as information previously stored in the cache can often be re-used. This reduces bandwidth and processing requirements of the web server, and helps to improve responsiveness for users of the web.


title: Cache (computing)

text: Web browsers employ a built-in web cache, but some Internet service providers (ISPs) or organizations also use a caching proxy server, which is a web cache that is shared among all users of that network.


title: Cache (computing)

text: Another form of cache is P2P caching, where the files most sought for by peer-to-peer applications are stored in an ISP cache to accelerate P2P transfers. Similarly, decentralised equivalents exist, which allow communities to perform the same task for P2P traffic, for example, Corelli.


title: Cache (computing)

text: A cache can store data that is computed on demand rather than retrieved from a backing store. Memoization is an optimization technique that stores the results of resource-consuming function calls within a lookup table, allowing subsequent calls to reuse the stored results and avoid repeated computation. It is related to the dynamic programming algorithm design methodology, which can also be thought of as a means of caching.


title: Cache (computing)

text: A content delivery network (CDN) is a network of distributed servers that deliver pages and other Web content to a user, based on the geographic locations of the user, the origin of the web page and the content delivery server.


title: Cache (computing)

text: CDNs began in the late 1990s as a way to speed up the delivery of static content, such as HTML pages, images and videos. By replicating content on multiple servers around the world and delivering it to users based on their location, CDNs can significantly improve the speed and availability of a website or application. When a user requests a piece of content, the CDN will check to see if it has a copy of the content in its cache. If it does, the CDN will deliver the content to the user from the cache.


title: Cache (computing)

text: A cloud storage gateway, also known as an edge filer, is a hybrid cloud storage device that connects a local network to one or more cloud storage service, typically an object storage service such as Amazon S3. It provides a cache for frequently accessed data, providing high speed local access to frequently accessed data in the cloud storage service. Cloud storage gateways also provide additional benefits such as accessing cloud object storage through traditional file serving protocols as well as continued access to cached data during connectivity outages.


title: Cache (computing)

text: Write-through operation is common when operating over unreliable networks (like an Ethernet LAN), because of the enormous complexity of the coherency protocol required between multiple write-back caches when communication is unreliable. For instance, web page caches and client-side network file system caches (like those in NFS or SMB) are typically read-only or write-through specifically to keep the network protocol simple and reliable.


title: Cache (computing)

text: Search engines also frequently make web pages they have indexed available from their cache. For example, Google provides a "Cached" link next to each search result. This can prove useful when web pages from a web server are temporarily or permanently inaccessible.


title: Cache (computing)

text: Database caching can substantially improve the throughput of database applications, for example in the processing of indexes, data dictionaries, and frequently used subsets of data.


title: Cache (computing)

text: A distributed cache uses networked hosts to provide scalability, reliability and performance to the application. The hosts can be co-located or spread over different geographical regions.


title: Cache (computing)

text: The semantics of a "buffer" and a "cache" are not totally different; even so, there are fundamental differences in intent between the process of caching and the process of buffering.


title: Cache (computing)

text: Fundamentally, caching realizes a performance increase for transfers of data that is being repeatedly transferred. While a caching system may realize a performance increase upon the initial (typically write) transfer of a data item, this performance increase is due to buffering occurring within the caching system.


title: Cache (computing)

text: With read caches, a data item must have been fetched from its residing location at least once in order for subsequent reads of the data item to realize a performance increase by virtue of being able to be fetched from the cache's (faster) intermediate storage rather than the data's residing location. With write caches, a performance increase of writing a data item may be realized upon the first write of the data item by virtue of the data item immediately being stored in the cache's intermediate storage, deferring the transfer of the data item to its residing storage at a later stage or else occurring as a background process. Contrary to strict buffering, a caching process must adhere to a (potentially distributed) cache coherency protocol in order to maintain consistency between the cache's intermediate storage and the location where the data resides. Buffering, on the other hand,


title: Cache (computing)

text: With typical caching implementations, a data item that is read or written for the first time is effectively being buffered; and in the case of a write, mostly realizing a performance increase for the application from where the write originated. Additionally, the portion of a caching protocol where individual writes are deferred to a batch of writes is a form of buffering. The portion of a caching protocol where individual reads are deferred to a batch of reads is also a form of buffering, although this form may negatively impact the performance of at least the initial reads (even though it may positively impact the performance of the sum of the individual reads). In practice, caching almost always involves some form of buffering, while strict buffering does not involve caching.


title: Cache (computing)

text: A buffer is a temporary memory location that is traditionally used because CPU instructions cannot directly address data stored in peripheral devices. Thus, addressable memory is used as an intermediate stage. Additionally, such a buffer may be feasible when a large block of data is assembled or disassembled (as required by a storage device), or when data may be delivered in a different order than that in which it is produced. Also, a whole buffer of data is usually transferred sequentially (for example to hard disk), so buffering itself sometimes increases transfer performance or reduces the variation or jitter of the transfer's latency as opposed to caching where the intent is to reduce the latency. These benefits are present even if the buffered data are written to the buffer once and read from the buffer once.


title: Cache (computing)

text: A cache also increases transfer performance. A part of the increase similarly comes from the possibility that multiple small transfers will combine into one large block. But the main performance-gain occurs because there is a good chance that the same data will be read from cache multiple times, or that written data will soon be read. A cache's sole purpose is to reduce accesses to the underlying slower storage. Cache is also usually an abstraction layer that is designed to be invisible from the perspective of neighboring layers.


title: Toyota Corolla Cross

text: The is a compact crossover SUV (C-segment) produced by the Japanese automaker Toyota since 2020. Adopting the Corolla nameplate, it is positioned as a more practical and larger alternative to the C-HR and built on the same TNGA-C (GA-C) platform as the E210 series Corolla. By size, the Corolla Cross is positioned between the smaller C-HR – which the Corolla Cross shares platform with – and the larger RAV4 in Toyota's global crossover SUV lineup.


title: Toyota Corolla Cross

text: It was first unveiled in Thailand in July 2020 along with other Southeast Asian markets and Taiwan in the same year, while its introduction in other markets started in 2021.


title: Toyota Corolla Cross

text: The twin model of the Corolla Cross, called the Toyota Frontlander (), is available exclusively in China. It was introduced in late 2021.


title: Toyota Corolla Cross

text: The Corolla Cross is the second Toyota crossover built on the GA-C platform, after the smaller C-HR which was launched in 2016. The vehicle shares the same wheelbase as the C-HR, but occupies a larger footprint prioritising on interior space and practicality. For the front-wheel drive models, it is equipped with a MacPherson strut front suspension and a torsion beam rear suspension instead of an independent rear suspension used on the regular Corolla and the C-HR to save interior space and cut costs, while all-wheel drive models still come with rear independent units. Development was led by chief engineer Daizo Kameyama.


title: Toyota Corolla Cross

text: The interior is shared with the regular Corolla, with minor redesigns. It offers a claimed boot space of if equipped with a puncture repair kit, and with a temporary spare tyre.


title: Toyota Corolla Cross

text: , the Corolla Cross is produced in Japan, Thailand, Taiwan, Brazil, United States, Malaysia, China, and South Africa.


title: Toyota Corolla Cross

text: The conventional petrol model uses either a 1.8-litre "2ZR-FE"/"2ZR-FAE" regular/"2ZR-FBE" flex fuel or a 2.0-litre "M20A-FKS" regular/"M20A-FKB" flex fuel four-cylinder petrol engines that produces at 6,000 rpm and of torque at 4,000 rpm and at 6,600 rpm and of torque at 4,400–4,800 rpm respectively.


title: Toyota Corolla Cross

text: Hybrid variants uses either a 1.8-litre "2ZR-FXE" or a 2.0-litre "M20A-FXS" four-cylinder petrol engines. The 1.8-litre unit produces at 5,200 rpm and of torque at 3,600 rpm paired with an eCVT and works together with a 6.5-Ah nickel-metal hydride battery as well as an "1NM" AC synchronous electric motor rated at and to provide a total system output of . The 2.0-litre unit has a total system output of .


title: Toyota Corolla Cross

text: The Japanese market Corolla Cross was unveiled on 14 September 2021, with a differentiated front fascia from the global model (later shared with the Chinese market Frontlander and the North American market Corolla Cross Hybrid S/SE/XSE), headlight and taillight clusters (later shared with the European model), and the dedicated Corolla "C" front logo. Grade levels available are "X", G, S and Z, and is offered with a either 1.8-litre "2ZR-FAE" petrol or a 1.8-litre "2ZR-FXE" hybrid petrol engines. "E-Four" all-wheel drive is optional for the latter. Independent multi-link rear suspension setup is standard for E-Four models, while a panoramic roof is available for higher grades.


title: Toyota Corolla Cross

text: The Corolla Cross for the Thai market was launched on 9 July 2020. It was initially offered in 1.8 Sport, Hybrid Smart, Hybrid Premium and Hybrid Premium Safety grade levels. The Hybrid Premium Safety grade is equipped with Toyota Safety Sense. In September 2021, the Corolla Cross is given the Modellista accessories package on top of existing variants in Thailand. The GR Sport grade was released in November 2021 with a redesigned front fascia. The base Sport grade was replaced by Sport Plus grade in late November 2022.


title: Toyota Corolla Cross

text: The Corolla Cross for the Vietnamese market was launched on 5 August 2020. It is offered in 1.8 G, 1.8 V and 1.8 Hybrid grade levels. The 1.8 V and 1.8 Hybrid grades are equipped with Toyota Safety Sense.


title: Toyota Corolla Cross

text: The Indonesian market Corolla Cross was launched on 6 August 2020 and is offered in one petrol and hybrid models. Due to low sales, the conventional petrol model was no longer distributed to the dealers since August 2021.


title: Toyota Corolla Cross

text: The Corolla Cross for the Philippine market was launched on 20 August 2020 and initially offered in 1.8 G and 1.8 V Hybrid grade levels. The hybrid GR Sport variant was later introduced in March 2022.


title: Toyota Corolla Cross

text: The Corolla Cross (marketed as "Cross") for the Bruneian market was launched on 21 August 2020. It is only offered with a 1.8-litre "2ZR-FE" petrol engine in Standard or High grade levels.


title: Toyota Corolla Cross

text: The Corolla Cross for the Burmese market was launched on 4 September 2020 and is only offered in 1.8 V petrol model. The 1.8 V grade is equipped with Toyota Safety Sense.


title: Toyota Corolla Cross

text: The Corolla Cross for the Taiwanese market was launched on 12 October 2020. It is offered in 1.8 G, 1.8 V and 1.8 Hybrid grade levels. All grades are equipped with Toyota Safety Sense. The GR Sport grade was launched on 14 September 2021.


title: Toyota Corolla Cross

text: The Corolla Cross for the Malaysian market was launched on 25 March 2021. Initial grade levels are 1.8 G and 1.8 V. Both grades are offered with the 1.8-litre "2ZR-FE" engine paired with continuously variable transmission (CVT). The V grade is equipped with Toyota Safety Sense. The early batch of the car are imported from Thailand, while locally assembled model went on sale in October 2021 along with the introduction of the hybrid model. The hybrid version was launched on 14 January 2022. Deliveries for all CKD models started in early 2022.


title: Toyota Corolla Cross

text: The Corolla Cross for the Chinese market is produced and marketed by FAW Toyota, while its twin model, known as the Frontlander () is produced and marketed by GAC Toyota. Both the Corolla Cross and Frontlander was unveiled at the Guangzhou Auto Show in November 2021. The Frontlander adopts the Japanese model's front and rear styling. Both models are powered with a 2.0-litre "M20A-FKS" engine, and positioned as the entry-level SUV of Toyota in the market with a lower pricing compared to the C-HR/IZOA.


title: Toyota Corolla Cross

text: The Corolla Cross will be on sale in 2022 to compete in the C-segment SUV space. Built in Japan, the European market Corolla Cross is powered by a 2.0-litre "M20A-FXS" hybrid petrol engine with a combined output of . An all-wheel drive model (AWD-i) is available with an additional rear electric motor producing . It is equipped with the Japanese-model headlight and taillight clusters, while equipment list included panoramic roof, 12.3-inch instrument panel and a 10.5-inch central display.


title: Toyota Corolla Cross

text: The Corolla Cross was revealed in Brazil on 12 March 2021. Locally manufactured at the Sorocaba plant, it is powered by either a direct-injected 2.0-litre "M20A-FKB" flex fuel petrol engine for XR and XRE grade levels, or a 1.8-litre "2ZR-FXE" hybrid flex fuel unit for XRV and XRX grade levels. Toyota targeted the hybrid version to contribute 30 percent of Corolla Cross total sales in the country. It is also exported to 22 countries in Latin America and the Caribbean.


title: Toyota Corolla Cross

text: The Corolla Cross for the North American market was unveiled on 2 June 2021. The first vehicle to be built at the Mazda Toyota Manufacturing USA plant in Huntsville, Alabama, the production began on 30 September 2021. Initially only available with a 2.0-litre "M20A-FKS" petrol engine paired with the "K120" "Direct Shift" CVT, it was offered in L, LE and XLE grade levels in the United States and Canada, and in LE grade in Mexico, with an all-wheel drive system available as an option in former two markets.


title: Toyota Corolla Cross

text: The hybrid model with standard all-wheel drive debuted in June 2022 for the 2023 model year. Powered by a 2.0-litre "M20A-FXS" hybrid petrol engine, it is offered in LE, XLE, S, SE, and XSE grade levels. The S, SE, and XSE grades are newly introduced for the 2023 model year, which adopts the Japanese market Corolla Cross and the Chinese market Frontlander front fascia design and is equipped with a sport-tuned suspension.


title: Toyota Corolla Cross

text: The Corolla Cross was launched in Kenya on 18 November 2020 and is only offered with a 1.8-litre "2ZR-FE" petrol engine in Limited and Executive grade levels.


title: Toyota Corolla Cross

text: The Corolla Cross went on sale in South Africa in November 2021, available in Xi, XS, and XR grade levels. Produced locally at the Toyota South Africa Motors plant, it is powered by either a 1.8-litre "2ZR-FE" petrol or a 1.8-litre "2ZR-FXE" hybrid petrol engines. Four styling packages were offered: X-Over, Urban Sport, Adventure, and Hybrid.


title: Toyota Corolla Cross

text: The Corolla Cross was announced for the Australian market in August 2022, and went on sale on 12 October 2022. Imported from Japan and sharing the styling with the European market Corolla Cross, the grade levels offered are GX, GXL and Atmos with either a 2.0-litre "M20A-FKS" petrol or a 2.0-litre "M20A-FXS" hybrid petrol engines. All-wheel drive option is available for hybrid models.


title: Toyota Corolla Cross

text: The Corolla Cross for New Zealand market went on sale on 13 October 2022. Like the Australian model, it is imported from Japan and also shares the styling with the European market Corolla Cross. Grade levels offered are GX, GXL and Limited with either a 2.0-litre "M20A-FKS" petrol or a 2.0-litre "M20A-FXS" hybrid petrol engines. All-wheel drive option is available for hybrid models.


title: Toyota Corolla Cross

text: The Corolla Cross H2 Concept is a Corolla Cross prototype fitted with a modified "G16E-GTS" engine to run with hydrogen fuel.


title: Toyota Corolla Cross

text: The US market Corolla Cross was awarded the "Top Safety Pick+" by the Insurance Institute for Highway Safety in 2021. It received overall Good and Superior ratings on all categories except headlights, as only the XLE trim with Adaptive Front Lighting System received the Good rating while the other trims were rated Acceptable.


title: Snell's law

text: Snell's law (also known as Snell–Descartes law and ibn-Sahl law and the law of refraction) is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or air. This law was named after the Dutch astronomer and mathematician Willebrord Snellius (also called Snell).


title: Snell's law

text: In optics, the law is used in ray tracing to compute the angles of incidence or refraction, and in experimental optics to find the refractive index of a material. The law is also satisfied in meta-materials, which allow light to be bent "backward" at a negative angle of refraction with a negative refractive index.


title: Snell's law

text: Snell's law states that, for a given pair of media, the ratio of the sines of angle of incidence (formula_1) and angle of refraction (formula_2) is equal to the refractive index of the second medium w.r.t the first (n) which is equal to the ratio of the refractive indices (n/n) of the two media, or equivalently, to the ratio of the phase velocities (v/v) in the two media.


title: Snell's law

text: The law follows from Fermat's principle of least time, which in turn follows from the propagation of light as waves.


title: Snell's law

text: Ptolemy, in Alexandria, Egypt, had found a relationship regarding refraction angles, but it was inaccurate for angles that were not small. Ptolemy was confident he had found an accurate empirical law, partially as a result of slightly altering his data to fit theory (see: confirmation bias). Alhazen, in his "Book of Optics" (1021), came closer to discovering the law of refraction, though he did not take this step.


title: Snell's law

text: The Persian scientist Ibn Sahl, at the Baghdad court in 984, recorded ray diagrams but made no record of material properties relating to refractive index, so cannot lay claim to have discovered the law of refraction. In the manuscript "On Burning Mirrors and Lenses", Sahl used ray diagrams to derive lens shapes that focus light with no geometric aberrations.


title: Snell's law

text: The law was first discovered by Thomas Harriot in 1602, who however did not publish his results although he had corresponded with Kepler on this very subject. In 1621, the Dutch astronomer Willebrord Snellius (1580–1626)—Snell—derived a mathematically equivalent form, that remained unpublished during his lifetime. René Descartes independently derived the law using heuristic momentum conservation arguments in terms of sines in his 1637 essay "Dioptrique", and used it to solve a range of optical problems. Rejecting Descartes' solution, Pierre de Fermat arrived at the same solution based solely on his principle of least time. Descartes assumed the speed of light was infinite, yet in his derivation of Snell's law he also assumed the denser the medium, the greater the speed of light. Fermat supported the opposing assumptions, i.e., the speed of light is finite, and his derivation depended upon the speed of light being slower in a denser medium. Fermat's derivation also utilized his invention of adequality, a mathematical procedure equivalent to differential calculus, for finding maxima, minima, and tangents.


title: Snell's law

text: In his influential mathematics book "Geometry", Descartes solves a problem that was worked on by Apollonius of Perga and Pappus of Alexandria. Given n lines L and a point P(L) on each line, find the locus of points Q such that the lengths of the line segments QP(L) satisfy certain conditions. For example, when n = 4, given the lines a, b, c, and d and a point A on a, B on b, and so on, find the locus of points Q such that the product QA*QB equals the product QC*QD. When the lines are not all parallel, Pappus showed that the loci are conics, but when Descartes considered larger n, he obtained cubic and higher degree curves. To show that the cubic curves were interesting, he showed that they arose naturally in optics from Snell's law.


title: Snell's law

text: According to Dijksterhuis, "In "De natura lucis et proprietate" (1662) Isaac Vossius said that Descartes had seen Snell's paper and concocted his own proof. We now know this charge to be undeserved but it has been adopted many times since." Both Fermat and Huygens repeated this accusation that Descartes had copied Snell. In French, Snell's Law is called "la loi de Descartes" or "loi de Snell-Descartes."


title: Snell's law

text: In his 1678 "Traité de la Lumière", Christiaan Huygens showed how Snell's law of sines could be explained by, or derived from, the wave nature of light, using what we have come to call the Huygens–Fresnel principle.


title: Snell's law

text: With the development of modern optical and electromagnetic theory, the ancient Snell's law was brought into a new stage. In 1962, Bloembergen showed that at the boundary of nonlinear medium, the Snell's law should be written in a general form. In 2008 and 2011, plasmonic metasurfaces were also demonstrated to change the reflection and refraction directions of light beam.


title: Snell's law

text: Snell's law is used to determine the direction of light rays through refractive media with varying indices of refraction. The indices of refraction of the media, labeled formula_4, formula_5 and so on, are used to represent the factor by which a light ray's speed decreases when traveling through a refractive medium, such as glass or water, as opposed to its velocity in a vacuum.


title: Snell's law

text: As light passes the border between media, depending upon the relative refractive indices of the two media, the light will either be refracted to a lesser angle, or a greater one. These angles are measured with respect to the "normal line", represented perpendicular to the boundary. In the case of light traveling from air into water, light would be refracted towards the normal line, because the light is slowed down in water; light traveling from water to air would refract away from the normal line.


title: Snell's law

text: Refraction between two surfaces is also referred to as "reversible" because if all conditions were identical, the angles would be the same for light propagating in the opposite direction.


title: Snell's law

text: Snell's law is generally true only for isotropic or specular media (such as glass). In anisotropic media such as some crystals, birefringence may split the refracted ray into two rays, the "ordinary" or "o"-ray which follows Snell's law, and the other "extraordinary" or "e"-ray which may not be co-planar with the incident ray.


title: Snell's law

text: When the light or other wave involved is monochromatic, that is, of a single frequency, Snell's law can also be expressed in terms of a ratio of wavelengths in the two media, formula_6 and formula_7:


title: Snell's law

text: Snell's law can be derived from Fermat's principle, which states that the light travels the path which takes the least time. By taking the derivative of the optical path length, the stationary point is found giving the path taken by the light. (There are situations of light violating Fermat's principle by not taking the least time path, as in reflection in a (spherical) mirror.) In a classic analogy, the area of lower refractive index is replaced by a beach, the area of higher refractive index by the sea, and the fastest way for a rescuer on the beach to get to a drowning person in the sea is to run along a path that follows Snell's law.


title: Snell's law

text: As shown in the figure to the right, assume the refractive index of medium 1 and medium 2 are formula_4 and formula_5 respectively. Light enters medium 2 from medium 1 via point O.


title: Snell's law

text: formula_11 is the angle of incidence, formula_12 is the angle of refraction with respect to the normal.


title: Snell's law

text: Alternatively, Snell's law can be derived using interference of all possible paths of light wave from source to observer—it results in destructive interference everywhere except extrema of phase (where interference is constructive)—which become actual paths.


title: Snell's law

text: Another way to derive Snell's Law involves an application of the general boundary conditions of Maxwell equations for electromagnetic radiation and induction.


title: Snell's law

text: Yet another way to derive Snell's law is based on translation symmetry considerations. For example, a homogeneous surface perpendicular to the z direction cannot change the transverse momentum. Since the propagation vector formula_24 is proportional to the photon's momentum, the transverse propagation direction formula_25 must remain the same in both regions. Assume without loss of generality a plane of incidence in the formula_26 plane formula_27. Using the well known dependence of the wavenumber on the refractive index of the medium, we derive Snell's law immediately.


title: Snell's law

text: where formula_31 is the wavenumber in vacuum. Although no surface is truly homogeneous at the atomic scale, full translational symmetry is an excellent approximation whenever the region is homogeneous on the scale of the light wavelength.


title: Snell's law

text: Given a normalized light vector formula_32 (pointing from the light source toward the surface) and a normalized plane normal vector formula_33, one can work out the normalized reflected and refracted rays, via the cosines of the angle of incidence formula_11 and angle of refraction formula_12, without explicitly using the sine values or any trigonometric functions or angles:


title: Snell's law

text: Note: formula_37 must be positive, which it will be if formula_33 is the normal vector that points from the surface toward the side where the light is coming from, the region with index formula_4. If formula_37 is negative, then formula_33 points to the side without the light, so start over with formula_33 replaced by its negative.


title: Snell's law

text: This reflected direction vector points back toward the side of the surface where the light came from.


title: Snell's law

text: Now apply Snell's law to the ratio of sines to derive the formula for the refracted ray's direction vector:


title: Snell's law

text: The formula may appear simpler in terms of renamed simple values formula_47 and formula_48, avoiding any appearance of trig function names or angle names:


title: Snell's law

text: The cosine values may be saved and used in the Fresnel equations for working out the intensity of the resulting rays.


title: Snell's law

text: Total internal reflection is indicated by a negative radicand in the equation for formula_53, which can only happen for rays crossing into a less-dense medium (formula_54).


title: Snell's law

text: When light travels from a medium with a higher refractive index to one with a lower refractive index, Snell's law seems to require in some cases (whenever the angle of incidence is large enough) that the sine of the angle of refraction be greater than one. This of course is impossible, and the light in such cases is completely reflected by the boundary, a phenomenon known as total internal reflection. The largest possible angle of incidence which still results in a refracted ray is called the critical angle; in this case the refracted ray travels along the boundary between the two media.


title: Snell's law

text: For example, consider a ray of light moving from water to air with an angle of incidence of 50°. The refractive indices of water and air are approximately 1.333 and 1, respectively, so Snell's law gives us the relation


title: Snell's law

text: In many wave-propagation media, wave velocity changes with frequency or wavelength of the waves; this is true of light propagation in most transparent substances other than a vacuum. These media are called dispersive. The result is that the angles determined by Snell's law also depend on frequency or wavelength, so that a ray of mixed wavelengths, such as white light, will spread or disperse. Such dispersion of light in glass or water underlies the origin of rainbows and other optical phenomena, in which different wavelengths appear as different colors.


title: Snell's law

text: In optical instruments, dispersion leads to chromatic aberration; a color-dependent blurring that sometimes is the resolution-limiting effect. This was especially true in refracting telescopes, before the invention of achromatic objective lenses.


title: Snell's law

text: In a conducting medium, permittivity and index of refraction are complex-valued. Consequently, so are the angle of refraction and the wave-vector. This implies that, while the surfaces of constant real phase are planes whose normals make an angle equal to the angle of refraction with the interface normal, the surfaces of constant amplitude, in contrast, are planes parallel to the interface itself. Since these two planes do not in general coincide with each other, the wave is said to be inhomogeneous. The refracted wave is exponentially attenuated, with exponent proportional to the imaginary component of the index of refraction.


title: Siege of Baghdad (1258)

text: The siege of Baghdad was a siege that took place in Baghdad in 1258, lasting for 13 days from January 29, 1258 until February 10, 1258. The siege, laid by Ilkhanate Mongol forces and allied troops, involved the investment, capture, and sack of Baghdad, which was the capital of the Abbasid Caliphate at that time. The Mongols were under the command of Hulagu Khan, brother of the khagan Möngke Khan, who had intended to further extend his rule into Mesopotamia but not to directly overthrow the Caliphate. Möngke, however, had instructed Hulagu to attack Baghdad if the Caliph Al-Musta'sim refused Mongol demands for his continued submission to the khagan and the payment of tribute in the form of military support for Mongol forces in Persia.


title: Siege of Baghdad (1258)

text: Hulagu began his campaign in Persia against the strongholds of Nizari Ismailis, who lost their stronghold of Alamut. He then marched on Baghdad, demanding that Al-Musta'sim accede to the terms imposed by Möngke on the Abbasids. Although the Abbasids had failed to prepare for the invasion, the Caliph believed that Baghdad could not fall to invading forces and refused to surrender. Hulagu subsequently besieged the city, which surrendered after 12 days.


title: Siege of Baghdad (1258)

text: During the next week, the Mongols sacked Baghdad, committing numerous atrocities; there is debate among historians about the level of destruction of library books and the Abbasids' vast libraries. The Mongols executed Al-Musta'sim and massacred many residents of the city, which was left greatly depopulated. The siege is considered to mark the end of the Islamic Golden Age, during which the caliphs had extended their rule from the Iberian Peninsula to Sindh, and which was also marked by many cultural achievements in diverse fields.


title: Siege of Baghdad (1258)

text: Baghdad had for centuries been the capital of the Abbasid Caliphate, the third caliphate, whose rulers were descendants of Abbas, an uncle of Muhammad. In 751, the Abbasids overthrew the Umayyads and moved the Caliph's seat from Damascus to Baghdad. At the city's peak, it was populated by approximately one million people and was defended by an army of 60,000 soldiers. By the middle of the 13th century the power of the Abbasids had declined and Turkic and Mamluk warlords often held power over the Caliphs.


title: Siege of Baghdad (1258)

text: Baghdad still retained much symbolic significance, and it remained a rich and cultured city. The Caliphs of the 12th and 13th centuries had begun to develop links with the expanding Mongol Empire in the east. Caliph an-Nasir li-dini'llah, who reigned from 1180–1225, may have attempted an alliance with Genghis Khan when Muhammad II of Khwarezm threatened to attack the Abbasids. It has been rumored that some Crusader captives were sent as tribute to the Mongol khagan.


title: Siege of Baghdad (1258)

text: According to "The Secret History of the Mongols", Genghis and his successor, Ögedei Khan, ordered their general Chormaqan to attack Baghdad. In 1236, Chormaqan led a division of the Mongol army to Irbil, which remained under Abbasid rule. Further raids on Irbil and other regions of the caliphate became nearly annual occurrences. Some raids were alleged to have reached Baghdad itself, but these Mongol incursions were not always successful, with Abbasid forces defeating the invaders in 1238 and 1245.


title: Siege of Baghdad (1258)

text: Despite their successes, the Abbasids hoped to come to terms with the Mongols and by 1241 had adopted the practice of sending an annual tribute to the court of the khagan. Envoys from the Caliph were present at the coronation of Güyük Khan as khagan in 1246 and that of Möngke Khan in 1251. During his brief reign, Güyük insisted that the Caliph Al-Musta'sim fully submit to Mongol rule and come personally to Karakorum. The khagans blamed Baiju for the Caliph's refusal and other resistance by the Abbasids to increased attempts by the Mongols to extend their power.


title: Siege of Baghdad (1258)

text: In 1257, Möngke resolved to establish firm authority over Mesopotamia, Syria, and Persia. The khagan gave his brother, Hulagu, authority over a subordinate khanate and army, the Ilkhanate, and instructions to compel the submission of various Muslim states, including the caliphate. Though not seeking the overthrow of Al-Musta'sim, Möngke ordered Hulagu to destroy Baghdad if the Caliph refused his demands of personal submission to Hulagu and the payment of tribute in the form of a military detachment, which would reinforce Hulagu's army during its campaigns against Persian Ismaili states.


title: Siege of Baghdad (1258)

text: In preparation for his invasion, Hulagu raised a large expeditionary force, conscripting one out of every ten military-age males in the entirety of the Mongol Empire, assembling what may have been the most numerous Mongol army to have existed and, by one estimate, 150,000 strong. Generals of the army included the Oirat administrator Arghun Agha, Baiju, Buqa Temür, Guo Kan, and Kitbuqa, as well as Hulagu's brother Sunitai and various other warlords. The force was also supplemented by Christian forces, including the King of Armenia and his army, a Frankish contingent from the Principality of Antioch, and a Georgian force, seeking revenge on the Muslim Abbasids for the sacking of their capital, Tiflis, decades earlier by the Khwarazm-Shahs. About 1,000 Chinese artillery experts accompanied the army, as did Persian and Turkic auxiliaries, according to Ata-Malik Juvayni, a contemporary Persian observer.


title: Siege of Baghdad (1258)

text: Hulagu led his army first to Persia, where he successfully campaigned against the Lurs, the Bukhara, and the remnants of the Khwarezm-Shah dynasty. After subduing them, Hulagu directed his attention toward the Nizari Ismailis and their Grand Master, Imam Ala al-Din Muhammad, who had attempted the murder of both Möngke and Hulagu's friend and subordinate, Kitbuqa. Though the Order of Assassins failed in both attempts, Hulagu marched his army to their stronghold of Alamut, which he captured. The Mongols later executed the Assassins' Grand Master, Imam Rukn al-Din Khurshah, who had briefly succeeded 'Ala al-Din Muhammad from 1255–1256.


title: Siege of Baghdad (1258)

text: After defeating the Assassins, Hulagu sent word to Al-Musta'sim, demanding his acquiescence to the terms imposed by Möngke. Al-Musta'sim refused, in large part due to the influence of his advisor and grand vizier, Ibn al-Alkami. Historians have ascribed various motives to al-Alkami's opposition to submission, including treachery and incompetence. Either way, it appears that he misled the Caliph about the severity of the invasion and assured Al-Musta'sim that, if the capital of the caliphate were to be endangered by a Mongol army, the Islamic world would rush to its aid.


title: Siege of Baghdad (1258)

text: Although he replied to Hulagu's demands in a manner that the Mongol commander found menacing and offensive enough to break off negotiations, Al-Musta'sim neglected to summon armies to reinforce the troops at his disposal in Baghdad. Nor did he strengthen the city's walls. By January 11 the Mongols were close to the city, establishing themselves on both banks of the Tigris River so as to form a pincer around the city. Al-Musta'sim finally decided to do battle with them and sent out a force of 20,000 cavalry to attack the Mongols. The cavalry were decisively defeated by the Mongols, whose sappers breached dikes along the Tigris River and flooded the ground behind the Abbasid forces, trapping them.


title: Siege of Baghdad (1258)

text: The Abbasid caliphate supposedly called upon 50,000 soldiers for the defense of their capital, including the 20,000 cavalry under al-Musta'sim. However, these troops were assembled hastily, making them poorly equipped and disciplined. Although the caliph technically had the authority to summon soldiers from other Muslim empires to defend his realm, he neglected or lacked the ability to do so. His taunting opposition had lost him the loyalty of the Mamluks, and the Syrian emirs, whom he supported, were busy preparing their own defenses.


title: Siege of Baghdad (1258)

text: On January 29, the Mongol army began its siege of Baghdad, constructing a palisade and a ditch around the city. Employing siege engines and catapults, the Mongols attempted to breach the city's walls, and, by February 5, had seized a significant portion of the defenses. Realizing that his forces had little chance of retaking the walls, Al-Musta'sim attempted to open negotiations with Hulagu, who rebuffed the Caliph. Around 3,000 of Baghdad's notables also tried to negotiate with Hulagu but were murdered. Five days later, on February 10, the city surrendered, but the Mongols did not enter the city until the 13th, beginning a week of massacre and destruction.


title: Siege of Baghdad (1258)

text: Many historical accounts detailed the cruelties of the Mongol conquerors. Baghdad was a depopulated, ruined city for several decades and only gradually recovered some of its former glory.


title: Siege of Baghdad (1258)

text: Contemporary accounts state Mongol soldiers looted and then destroyed mosques, palaces, libraries, and hospitals. Priceless books from Baghdad's thirty-six public libraries were torn apart, the looters using their leather covers as sandals. Grand buildings that had been the work of generations were burned to the ground. The House of Wisdom (the Grand Library of Baghdad), containing countless precious historical documents and books on subjects ranging from medicine to astronomy, was destroyed. Claims have been made that the Tigris ran red from the blood of the scientists and philosophers killed. Images of violence toward books appear in the 14th century; the tale of the destruction of books – tossed into the Tigris such that the water turned black from the ink – seems to originate from the 16th century. Michal Biran argues that this story was likely a literary trope to demonstrate Mongol barbarity.


title: Siege of Baghdad (1258)

text: Citizens attempted to flee, but were intercepted by Mongol soldiers who killed in abundance, sparing no one, not even children. Martin Sicker writes that close to 90,000 people may have died. Other estimates go much higher, but are almost certainly exaggerated.


title: Siege of Baghdad (1258)

text: The caliph Al-Musta'sim was captured and forced to watch as his citizens were murdered and his treasury plundered. According to most accounts, the caliph was killed by trampling. The Mongols rolled the caliph up in a rug, and rode their horses over him, as they believed that the earth would be offended if it were touched by royal blood. All but one of Al-Musta'sim's sons were killed, and the sole surviving son was sent to Mongolia, where Mongolian historians report he married and fathered children, but played no role in Islam thereafter (see The end of the Abbasid dynasty).


title: Siege of Baghdad (1258)

text: The historian David Morgan has quoted Wassaf (who himself was born in 1265, seven years after the razing of the city) describing the destruction: "They swept through the city like hungry falcons attacking a flight of doves, or like raging wolves attacking sheep, with loose reins and shameless faces, murdering and spreading terror...beds and cushions made of gold and encrusted with jewels were cut to pieces with knives and torn to shreds. Those hiding behind the veils of the great Harem were dragged...through the streets and alleys, each of them becoming a plaything...as the population died at the hands of the invaders."


title: Siege of Baghdad (1258)

text: Some modern historians have cast some doubt on the vehemently anti-Mongol medieval sources. George Lane (SOAS), for example, doubts the Grand Library was destroyed, as the learned members of the Mongol command such as Nasir al-Din Tusi would not have allowed it, and that disease was the major cause of death. Primary sources state that Tusi saved thousands of volumes and installed them into a building in Marāgheh.


title: Siege of Baghdad (1258)

text: Some historians believe that the Mongol invasion destroyed much of the irrigation infrastructure that had sustained Mesopotamia for many millennia. Canals were cut as a military tactic and never repaired. So many people died or fled that neither the labour nor the organization were sufficient to maintain the canal system. It broke down or silted up. This theory was advanced (not for the first time) by historian Svatopluk Souček in his 2000 book, "A History of Inner Asia."


title: Siege of Baghdad (1258)

text: Hulagu left 3,000 Mongol soldiers behind to rebuild Baghdad. Ata-Malik Juvayni was later appointed governor of Baghdad, Lower Mesopotamia, and Khuzistan after Guo Kan went back to the Yuan dynasty to assist Kublai's conquest over the Song dynasty. Hulagu's Nestorian Christian wife, Dokuz Khatun, successfully interceded to spare the lives of Baghdad's Christian inhabitants. Hulagu offered the royal palace to the Nestorian Catholicos Mar Makikha, and ordered a cathedral to be built for him.


title: Siege of Baghdad (1258)

text: Initially, the fall of Baghdad came as a shock to the whole Muslim world. But after many years of utter devastation, the city gradually became an economic center where international trade, the minting of coins and religious affairs flourished under the succeeding Ilkhanate. The chief Mongol darughachi was thereafter stationed in the city.


title: Siege of Baghdad (1258)

text: Berke Khan, a grandson of Genghis Khan who had converted to Islam in 1252, became enraged that Hulagu destroyed Baghdad. Muslim historian Rashid al Din quoted Berke Khan as sending the following message to Mongke Khan, protesting the attack on Baghdad, (not knowing Mongke had died in China): "He (Hulagu) has sacked all the cities of the Muslims. With the help of God I will call him to account for so much innocent blood."