title: Maputo

text: An important cultural and artists' centre in Maputo is the Associação Núcleo de Arte. It is the oldest collective of artists in Mozambique. Seated in an old villa in the centre of Maputo the Núcleo has played a significant role in metropolitan cultural life for decades. The two best known and most influential contemporary Mozambican artists started their career at Núcleo de Arte, the painter Malangatana Ngwenya and the sculptor Alberto Chissano. Over one hundred painters, sculptors and ceramists are members of the Núcleo, which regularly stages exhibitions on its own premises and over the last few years has actively participated in exchanges with artists from abroad. The Núcleo became well known for their project transforming arms into tools and objects of art. It played an important role for reconciliation after the Mozambican Civil War. The exhibition of art objects such as the Chair of the African King and the Tree of Life was shown around the world, among others in the British Museum in 2006.


title: Maputo

text: Maputo is home to the Dockanema Documentary Film Festival, and international festival showcasing documentary films from around the world.


title: Maputo

text: During its five centuries of Portuguese colonialization, the city has gained several examples of Portuguese architecture. Most of the note-worthy buildings are former colonial administrative buildings or current government buildings.


title: Maputo

text: Among the places of worship, they are predominantly Christian churches and temples : Roman Catholic Archdiocese of Maputo (Catholic Church), Reformed Church in Mozambique (World Communion of Reformed Churches), Igreja Presbiteriana de Moçambique (World Communion of Reformed Churches), Convenção Baptista de Moçambique (Baptist World Alliance), Universal Church of the Kingdom of God, Assemblies of God, Zion Christian Church. There are also Muslim mosques.


title: Maputo

text: The city does not yet have a very expansive list of parks and other recreational areas. However, at the center of the city lies the Jardim Tunduru (Tunduru Gardens) which was formerly called the Vasco Da Gama Garden. It was designed in the 1880s by a British architect, Thomas Honney. The entrance of the park is designed in the Neo-Manueline style. After independence, the name was changed to the current one and a statue of the country's first president was erected.


title: Maputo

text: Maputo offers several options for education with pre-schools, primary, secondary schools and higher education institutions. The quality of the syllabus is said to differ greatly depending on whether an institution is private or public.


title: Maputo

text: Mozambique's largest higher education institution is the Universidade Eduardo Mondlane which was established in 1968 as the Universidade de Lourenço Marques. Most of the universities faculties and departments are located in the city of Maputo with nearly 8,000 students attending 10 faculties. Some faculties also exist in Beira, Quelimane, Nampula and Inhambane.


title: Maputo

text: Since the 1990s there has also been a rapid growth of private education houses offering higher education such as "Instituto Superior de Ciências e Tecnologias de Moçambique" (ISCTEM), "Instituto Superior de Tecnologias e Gestão" (ISTEG) and "Instituto Superior de Transportes e Comunicações" (ISUTC).


title: Maputo

text: In the secondary education market, there is again a strong divergence between private and public schooling.


title: Maputo

text: Some expatriates have chosen to enroll their children in schools in Mbombela, South Africa and Waterford Kamhlaba in Mbabane, Eswatini.


title: Maputo

text: Maputo has several hospitals and clinics, including the city and country's largest hospital, the Hospital Central de Maputo (Maputo Central Hospital). Other hospitals include the public Hospital Geral José Macamo, and the private Clinica Sommerschield, the Clínica Cruz Azul in "baixa" and Hospital Privado located across the Portuguese School.


title: Maputo

text: The construction of Hospital Miguel Bombarda began in 1900. In 1976, Samora Machel renamed the hospital as "Hospital Central de Maputo" (HCM). The hospital has 1500 beds for in-patients and has an estimated staff number of 3000. It is made of a multi-block structure with 35 separate buildings spanning an area of 163,800 m. The hospital has six departments: Medicine, Surgery, Pediatrics, Orthopedics, Gynaecology and Obstetrics. It also has divisions for Ophthalmology and Otolaryngology and a morgue. The hospital provides services for an average 700 out-patients a day and over of washing is done daily. In the early 1990s, a section of the hospital was divided and turned into a private clinic offering higher quality services for those who could afford it called the "Clínica Especial de Maputo". The residence for the head of medicine is on the corner of "Avenida Eduardo Mondlane" and "Avenida Salavador Allende". It is a historically valuable structure which was completed in 1908 and has since the 1990s been converted into a charming restaurant with colonial themes called "Restaurante 1908". The upper floors are still used by the hospital as offices.


title: Cytoplasm

text: In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are cytosol (a gel-like substance), the organelles (the cell's internal sub-structures), and various cytoplasmic inclusions. The cytoplasm is about 80% water and is usually colorless.


title: Cytoplasm

text: The submicroscopic ground cell substance or cytoplasmic matrix which remains after exclusion of the cell organelles and particles is groundplasm. It is the hyaloplasm of light microscopy, a highly complex, polyphasic system in which all resolvable cytoplasmic elements are suspended, including the larger organelles such as the ribosomes, mitochondria, the plant plastids, lipid droplets, and vacuoles.


title: Cytoplasm

text: Most cellular activities take place within the cytoplasm, such as many metabolic pathways including glycolysis, and processes such as cell division. The concentrated inner area is called the endoplasm and the outer layer is called the cell cortex or the ectoplasm.


title: Cytoplasm

text: Movement of calcium ions in and out of the cytoplasm is a signaling activity for metabolic processes.


title: Cytoplasm

text: The term was introduced by Rudolf von Kölliker in 1863, originally as a synonym for protoplasm, but later it has come to mean the cell substance and organelles outside the nucleus.


title: Cytoplasm

text: There has been certain disagreement on the definition of cytoplasm, as some authors prefer to exclude from it some organelles, especially the vacuoles and sometimes the plastids.


title: Cytoplasm

text: It remains uncertain how the various components of the cytoplasm interact to allow movement of organelles while maintaining the cell's structure. The flow of cytoplasmic components plays an important role in many cellular functions which are dependent on the permeability of the cytoplasm. An example of such function is cell signalling, a process which is dependent on the manner in which signaling molecules are allowed to diffuse across the cell. While small signaling molecules like calcium ions are able to diffuse with ease, larger molecules and subcellular structures often require aid in moving through the cytoplasm. The irregular dynamics of such particles have given rise to various theories on the nature of the cytoplasm.


title: Cytoplasm

text: There has long been evidence that the cytoplasm behaves like a sol-gel. It is thought that the component molecules and structures of the cytoplasm behave at times like a disordered colloidal solution (sol) and at other times like an integrated network, forming a solid mass (gel). This theory thus proposes that the cytoplasm exists in distinct fluid and solid phases depending on the level of interaction between cytoplasmic components, which may explain the differential dynamics of different particles observed moving through the cytoplasm. A papers suggested that at length scale smaller than 100 nm, the cytoplasm acts like a liquid, while in a larger length scale, it acts like a gel.


title: Cytoplasm

text: Recently it has been proposed that the cytoplasm behaves like a glass-forming liquid approaching the glass transition. In this theory, the greater the concentration of cytoplasmic components, the less the cytoplasm behaves like a liquid and the more it behaves as a solid glass, freezing more significant cytoplasmic components in place (it is thought that the cell's metabolic activity can fluidize the cytoplasm to allow the movement of such more significant cytoplasmic components). A cell's ability to vitrify in the absence of metabolic activity, as in dormant periods, may be beneficial as a defense strategy. A solid glass cytoplasm would freeze subcellular structures in place, preventing damage, while allowing the transmission of tiny proteins and metabolites, helping to kickstart growth upon the cell's revival from dormancy.


title: Cytoplasm

text: Research has examined the motion of cytoplasmic particles independent of the nature of the cytoplasm. In such an alternative approach, the aggregate random forces within the cell caused by motor proteins explain the non-Brownian motion of cytoplasmic constituents.


title: Cytoplasm

text: The cytosol is the portion of the cytoplasm not contained within membrane-bound organelles. Cytosol makes up about 70% of the cell volume and is a complex mixture of cytoskeleton filaments, dissolved molecules, and water. The cytosol's filaments include the protein filaments such as actin filaments and microtubules that make up the cytoskeleton, as well as soluble proteins and small structures such as ribosomes, proteasomes, and the mysterious vault complexes. The inner, granular and more fluid portion of the cytoplasm is referred to as endoplasm.


title: Cytoplasm

text: Due to this network of fibres and high concentrations of dissolved macromolecules, such as proteins, an effect called macromolecular crowding occurs and the cytosol does not act as an ideal solution. This crowding effect alters how the components of the cytosol interact with each other.


title: Cytoplasm

text: Organelles (literally "little organs") are usually membrane-bound structures inside the cell that have specific functions. Some major organelles that are suspended in the cytosol are the mitochondria, the endoplasmic reticulum, the Golgi apparatus, vacuoles, lysosomes, and in plant cells, chloroplasts.


title: Cytoplasm

text: The inclusions are small particles of insoluble substances suspended in the cytosol. A huge range of inclusions exist in different cell types, and range from crystals of calcium oxalate or silicon dioxide in plants, to granules of energy-storage materials such as starch, glycogen, or polyhydroxybutyrate. A particularly widespread example are lipid droplets, which are spherical droplets composed of lipids and proteins that are used in both prokaryotes and eukaryotes as a way of storing lipids such as fatty acids and sterols. Lipid droplets make up much of the volume of adipocytes, which are specialized lipid-storage cells, but they are also found in a range of other cell types.


title: Cytoplasm

text: The cytoplasm, mitochondria, and most organelles are contributions to the cell from the maternal gamete. Contrary to the older information that disregards any notion of the cytoplasm being active, new research has shown it to be in control of movement and flow of nutrients in and out of the cell by viscoplastic behavior and a measure of the reciprocal rate of bond breakage within the cytoplasmic network.


title: Cytoplasm

text: The material properties of the cytoplasm remain an ongoing investigation. A method of determining the mechanical behaviour of living cell mammalian cytoplasm with the aid of optical tweezers has been described.


title: Heaviside step function

text: The Heaviside step function, or the unit step function, usually denoted by or (but sometimes , or ), is a step function, named after Oliver Heaviside (1850–1925), the value of which is zero for negative arguments and one for positive arguments. It is an example of the general class of step functions, all of which can be represented as linear combinations of translations of this one.


title: Heaviside step function

text: The function was originally developed in operational calculus for the solution of differential equations, where it represents a signal that switches on at a specified time and stays switched on indefinitely. Oliver Heaviside, who developed the operational calculus as a tool in the analysis of telegraphic communications, represented the function as .


title: Heaviside step function

text: Hence the Heaviside function can be considered to be the integral of the Dirac delta function. This is sometimes written as


title: Heaviside step function

text: although this expansion may not hold (or even make sense) for , depending on which formalism one uses to give meaning to integrals involving . In this context, the Heaviside function is the cumulative distribution function of a random variable which is almost surely 0. (See constant random variable.)


title: Heaviside step function

text: In operational calculus, useful answers seldom depend on which value is used for , since is mostly used as a distribution. However, the choice may have some important consequences in functional analysis and game theory, where more general forms of continuity are considered. Some common choices can be seen below.


title: Heaviside step function

text: Approximations to the Heaviside step function are of use in biochemistry and neuroscience, where logistic approximations of step functions (such as the Hill and the Michaelis–Menten equations) may be used to approximate binary cellular switches in response to chemical signals.


title: Heaviside step function

text: There are many other smooth, analytic approximations to the step function. Among the possibilities are:


title: Heaviside step function

text: These limits hold pointwise and in the sense of distributions. In general, however, pointwise convergence need not imply distributional convergence, and vice versa distributional convergence need not imply pointwise convergence. (However, if all members of a pointwise convergent sequence of functions are uniformly bounded by some "nice" function, then convergence holds in the sense of distributions too.)


title: Heaviside step function

text: In general, any cumulative distribution function of a continuous probability distribution that is peaked around zero and has a parameter that controls for variance can serve as an approximation, in the limit as the variance approaches zero. For example, all three of the above approximations are cumulative distribution functions of common probability distributions: the logistic, Cauchy and normal distributions, respectively.


title: Heaviside step function

text: where the second representation is easy to deduce from the first, given that the step function is real and thus is its own complex conjugate.


title: Heaviside step function

text: Since is usually used in integration, and the value of a function at a single point does not affect its integral, it rarely matters what particular value is chosen of . Indeed when is considered as a distribution or an element of (see space) it does not even make sense to talk of a value at zero, since such objects are only defined almost everywhere. If using some analytic approximation (as in the examples above) then often whatever happens to be the relevant limit at zero is used.


title: Heaviside step function

text: An alternative form of the unit step, defined instead as a function (that is, taking in a discrete variable ), is:


title: Heaviside step function

text: where is an integer. If is an integer, then must imply that , while must imply that the function attains unity at . Therefore the "step function" exhibits ramp-like behavior over the domain of , and cannot authentically be a step function, using the half-maximum convention.


title: Heaviside step function

text: The Fourier transform of the Heaviside step function is a distribution. Using one choice of constants for the definition of the Fourier transform we have


title: Heaviside step function

text: Here is the distribution that takes a test function to the Cauchy principal value of formula_22. The limit appearing in the integral is also taken in the sense of (tempered) distributions.


title: Heaviside step function

text: The Laplace transform of the Heaviside step function is a meromorphic function. Using the unilateral Laplace transform we have:


title: Heaviside step function

text: When the bilateral transform is used, the integral can be split in two parts and the result will be the same.


title: 2022 World Games

text: The 2022 World Games were an international multi-sport event held from July 7 to 17, 2022, in Birmingham, Alabama, United States. They were the 11th World Games, a multi-sport event featuring disciplines of Olympic sports and other competitions that are not currently contested at the Olympic Games; the Games featured 3,600 athletes competing in 206 medal events over 30 sports.


title: 2022 World Games

text: They were originally scheduled to be held in 2021, but were postponed by one year due to the COVID-19 pandemic. They were the second edition of the World Games to be hosted by the United States since their inaugural edition in 1981.


title: 2022 World Games

text: Barcelona and Santiago also considered bids. Cities paid a $125,000 application fee, and submitted information about "venues, infrastructure, volunteers, budget, transportation[,] and other elements".


title: 2022 World Games

text: Birmingham's bid, publicly announced in June 2014, was presented by Edgar Welden, Scott Myers, and David Benck. It was the only American city authorized to make a bid for these games. Myers, the executive director of the Alabama Sports Hall of Fame and Museum, said the bid was "a dream, but it's not a pipe dream. It's attainable." At the time, organizers projected a budget of $75 million, and the Greater Birmingham Convention and Visitors Bureau anticipated a windfall of between $224.4 million and $288.6 million in out-of-town dollars.


title: 2022 World Games

text: On January 22, 2015, at its meeting in Lausanne, the International World Games Association (IWGA) elected Birmingham as host of the 2021 World Games.


title: 2022 World Games

text: On April 4, 2020, the Games were postponed to 2022 due to the COVID-19 pandemic and the associated postponement of the 2020 Summer Olympics.


title: 2022 World Games

text: The 2022 World Games programme featured 30 official sports including 54 disciplines encompassing 206 events. This was the first time that drone racing, canoe marathon, breaking, women's fistball, kickboxing, and parkour were included in the World Games as official sports. Softball and racquetball returned to the official World Games programme. Invitational sports comprising 17 events included duathlon, flag football, wheelchair rugby, wushu (taolu) and men's lacrosse. Both men's and women's field lacrosse were played in a six-a-side format. The numbers in parentheses indicate the number of medal events contested in each sports discipline.


title: 2022 World Games

text: On 19 February 2021, the International Olympic Committee announced that certain Russian athletes would be allowed to compete under the designation "ROC" (for Russian Olympic Committee) at the Tokyo 2020 and Beijing 2022 Winter Games. This penalty also applies through end of 2022 and would have been applied to events affiliated with the International Olympic Committee, such as The World Games.


title: 2022 World Games

text: Following the 2022 Russian invasion of Ukraine, athletes from Russia along with Belarus were barred from the 2022 World Games, per the IOC's recommendations. Russia originally qualified 62 athletes while Belarus was set to send 11 athletes. Part of the ticket revenue was donated to Ukraine for rebuilding sports venues after the Russian invasion of the country.


title: 2022 World Games

text: Athletes from 110 National Olympic Committees were scheduled to participate. In total, athletes from 99 delegations competed at the 2022 World Games. The only representative team in the 2022 World Games not represented by a National Olympic Committee were the Haudenosaunee teams competing in lacrosse.


title: 2022 World Games

text: The games cost $65.1 million to produce. However, after only generating $51 million in revenue from sponsorships and tickets, it resulted in a current loss of $14.1 million. In August 2022, Games CEO Nick Sellers said in a statement: “We have every intention to raise the associated funds and pay our vendors.”


title: 2022 World Games

text: In the Women's 4 × 50 m obstacle relay of the lifesaving competition, two gold medals were awarded and thus no silver medal was awarded. In the Women's 500 m sprint of the track speed skating competition, only the one gold medal was awarded as the remaining competitors in the final were disqualified.


title: 2022 World Games

text: In March 2019, The World Games 2022 unveiled a mobile experience, designed to generate excitement for the event and educate the local community on the sports of The 2022 Games. The traveling Mercedes Sprinter Van includes a rock climbing wall, a sumo wrestling activity, photo opportunities and an interactive trivia game where guests can win prizes. The van made its official debut at the 15th Annual MortgageBanc Chili Cook-Off on March 2, 2019. It continues to tour throughout 2019, 2020, 2021 and 2022.


title: 2022 World Games

text: In June 2019, The World Games 2022 announced the kickoff of their supplier diversity program, World of Opportunity. The program, which was unveiled to an audience of 400 at the Birmingham Crossplex, allows certified, diverse businesses to compete for contracts to provide goods and services for The World Games 2022. The categories accepted include (but are not limited to) transportation services, event production, security, promotional items, merchandise, sports equipment, food service, technology, printing, medical supplies, event equipment, waste removal and construction services.


title: 2022 World Games

text: In July 2021, it was announced that CBS Sports Network would broadcast one-hour highlights shows on each of the ten days of competition, and two additional one-hour specials will be shown on other CBS channels and on Paramount+. Olympic Channel also carried coverage.


title: Tughlaq dynasty

text: The Tughlaq dynasty (), also referred to as Tughluq or Tughluk dynasty, was a Muslim dynasty of Indo-Turkic origin which ruled over the Delhi sultanate in medieval India. Its reign started in 1320 in Delhi when Ghazi Malik assumed the throne under the title of Ghiyath al-Din Tughluq. The dynasty ended in 1413.


title: Tughlaq dynasty

text: The dynasty expanded its territorial reach through a military campaign led by Muhammad ibn Tughluq, and reached its zenith between 1330 and 1335. It ruled most of the Indian subcontinent.


title: Tughlaq dynasty

text: The etymology of the word "Tughluq" is not certain. The 16th-century writer Firishta claims that it is a corruption of the Turkic term "Qutlugh", but this is doubtful. Literary, numismatic and epigraphic evidence makes it clear that Tughluq was the personal name of the dynasty's founder Ghiyath al-Din, and not an ancestral designation. Historians use the designation "Tughluq" to describe the entire dynasty as a matter of convenience, but the dynasty's kings did not use "Tughluq" as a surname: only Ghiyath al-Din's son Muhammad bin Tughluq called himself the son of Tughluq Shah ("bin Tughluq").


title: Tughlaq dynasty

text: The ancestry of the dynasty is debated among modern historians because the earlier sources provide different information regarding it. Tughluq's court poet Badr-i Chach attempted to find a royal Sassanian genealogy for the dynasty from the line of Bahram Gur, which seems to be the official position of the genealogy of the Sultan, although this can be dismissed as flattery.


title: Tughlaq dynasty

text: Peter Jackson suggested that Tughlaq was of Mongol stock and a follower of the Mongol chief Alaghu. The Moroccan traveler Ibn Battuta states that Tughluq belonged to the "Qarauna tribe of the Turks", who lived in the hilly region between Turkestan and Sindh, based on the claim of a Sufi saint Rukn-e-Alam. However, this is not corroborated by other contemporary sources. Qara'unas were Mongols or associated with Mongol armies, whom Tughlaq despised, and it is unlikely that Tughlaq was a Qara'una.


title: Tughlaq dynasty

text: Another Tughluq's court poet Amir Khusrau in his "Tughluq Nama" makes no mention of Tughluq's arrival in India from a foreign land, which seems to imply he was born in India. His own court poet states that Tughluq described himself frankly as a man of no importance (""awara mard"") in his early life and career. Tughlaq Nama declares Tughlaq to have been a minor chief of humble origins. Tughluq was a Multani by origins. The historian Ferishta, based on inquiries at Lahore, wrote that the knowledgeable historians and the books of India had neglected to mention any clear statement on the origin of the dynasty, but wrote that there was a rural founding myth that Tughluq's father was a Turkic slave of Balban who made an alliance with a Jatt chieftain of Punjab, and that Tughluq's mother may have been a Jatt lady. However there is no contemporary sources corroborate this statement. The historian Fouzia Ahmed points out that as per Amir Khusrau's assertion, Tughluq was not a Balbanid slave because he was not part of the old Turkic nobility and his family only became emergent during Khalji rule. Instead, Tughluq expressed his loyalty to the ethnically heterogenous Khalji regime through which he first entered military service rather than to Balban because his father was never part of Balban's old Sultanate household. However, this genealogical link with the Punjab paved the way for several other linkages, such his brother's marriage with the daughter of a Punjabi Bhatti chief, and the patronization of the sufi shrine of Baba Farid at Pakpattan. The Sultans held the family of Baba Farid in reverence because the home of the dynasty of Dipalpur was close to Pakpattan, and Sultan Muhammad Shah married his daughter to the grandson of Baba Farid. The link with the region was also exemplified in the support of the Khokhar tribes to Ghazi Malik, who were crucial in his rise to the monarchy. His own court poet, Amir Khusro, wrote a war ballad known as the Vaar in the Punjabi language for the Sultan describing the introduction to his rise to the throne against Khusrau Shah.


title: Tughlaq dynasty

text: The Khalji dynasty ruled the Delhi Sultanate before 1320. Its last ruler, Khusro Khan, was a Hindu slave who had been forcibly converted to Islam and then served the Delhi Sultanate as the general of its army for some time. Khusro Khan, along with Malik Kafur, had led numerous military campaigns on behalf of Alauddin Khalji, to expand the Sultanate and plunder non-Muslim kingdoms in India.


title: Tughlaq dynasty

text: After Alauddin Khalji's death from illness in 1316, a series of palace arrests and assassinations followed, with Khusro Khan coming to power in June 1320, after killing the licentious son of Alauddin Khalji, Mubarak Khalji, initiating a massacre of all members of the Khalji family and reverting from Islam. However, he lacked the support of the Muslim nobles and aristocrats of the Delhi Sultanate. Delhi's aristocracy invited Ghazi Malik, then the governor in Punjab under the Khaljis, to lead a coup in Delhi and remove Khusro Khan. In 1320, Ghazi Malik launched an attack with the use of an army of Khokhar tribesmen and killed Khusro Khan to assume power.


title: Tughlaq dynasty

text: After assuming power, Ghazi Malik renamed himself Ghiyasuddin Tughlaq – thus starting and naming the Tughlaq dynasty. Ghiyasuddin Tughlaq is also referred in scholarly works as Tughlak Shah. He was of mixed Turko-Indian origins; his mother was a Jatt noble and his father was likely descended from Indian Turkic slaves.


title: Tughlaq dynasty

text: Ghiyasuddin Tughlaq rewarded all those "maliks", "amirs" and officials of Khalji dynasty who had rendered him a service and helped him come to power. He punished those who had rendered service to Khusro Khan, his predecessor. He lowered the tax rate on Muslims that was prevalent during Khalji dynasty, but raised the taxes on Hindus, wrote his court historian Ziauddin Barani, so that they might not be blinded by wealth or afford to become rebellious.


title: Tughlaq dynasty

text: He built a city six kilometers east of Delhi, with a fort considered more defensible against the Mongol attacks, and called it Tughlakabad.


title: Tughlaq dynasty

text: In 1321, he sent his eldest son Ulugh Khan, later known as Muhammad bin Tughlaq, to Deogir to plunder the Hindu kingdoms of Arangal and Tilang (now part of Telangana). His first attempt was a failure. Four months later, Ghiyasuddin Tughlaq sent large army reinforcements for his son asking him to attempt plundering Arangal and Tilang again. This time Ulugh Khan succeeded. Arangal fell, was renamed to Sultanpur, and all plundered wealth, state treasury and captives were transferred from the captured kingdom to Delhi Sultanate.


title: Tughlaq dynasty

text: The Muslim aristocracy in Lukhnauti (Bengal) invited Ghiyasuddin Tughlaq to extend his coup and expand eastwards into Bengal by attacking Shamsuddin Firoz Shah, which he did over 1324–1325 AD, after placing Delhi under control of his son Ulugh Khan, and then leading his army to Lukhnauti. Ghiyasuddin Tughlaq succeeded in this campaign. As he and his favorite son Mahmud Khan were returning from Lakhnauti to Delhi, Ghiyasuddin Tughlaq's eldest son Ulugh Khan schemed to kill him inside a wooden structure ("kushk") built without foundation and designed to collapse, making it appear as an accident. Historic documents state that the Sufi preacher and Ulugh Khan had learnt through messengers that Ghiyasuddin Tughlaq had resolved to remove them from Delhi upon his return. Ghiyasuddin Tughlaq, along with Mahmud Khan, died inside the collapsed "kushk" in 1325 AD, while his eldest son watched. One official historian of Tughlaq court gives an alternate fleeting account of his death, as caused by a lightning bolt strike on the "kushk". Another official historian, Al-Badāʾunī ʻAbd al-Kadir ibn Mulūk-Shāh, makes no mention of lightning bolt or weather, but explains the cause of structural collapse to be the running of elephants; Al-Badaoni includes a note of the rumor that the accident was pre-planned.


title: Tughlaq dynasty

text: According to many historians such as Ibn Battuta, al-Safadi, Isami, and Vincent Smith, Ghiyasuddin was killed by his son Ulugh Juna Khan in 1325 AD. Juna Khan ascended to power as Muhammad bin Tughlaq, and ruled for 26 years.


title: Tughlaq dynasty

text: During Muhammad bin Tughluq's rule, Delhi Sultanate temporarily expanded to most of the Indian subcontinent, its peak in terms of geographical reach. He attacked and plundered Malwa, Gujarat, Mahratta, Tilang, Kampila, Dhur-samundar, Mabar, Lakhnauti, Chittagong, Sunarganw and Tirhut. His distant campaigns were expensive, although each raid and attack on non-Muslim kingdoms brought new looted wealth and ransom payments from captured people. The extended empire was difficult to retain, and rebellions all over Indian subcontinent became routine.


title: Tughlaq dynasty

text: He raised taxes to levels where people refused to pay any. In India's fertile lands between Ganges and Yamuna rivers, the Sultan increased the land tax rate on non-Muslims by tenfold in some districts, and twentyfold in others. Along with land taxes, dhimmis (non-Muslims) were required to pay crop taxes by giving up half or more of their harvested crop. These sharply higher crop and land tax led entire villages of Hindu farmers to quit farming and escape into jungles; they refused to grow anything or work at all. Many became robber clans. Famines followed. The Sultan responded with bitterness by expanding arrests, torture and mass punishments, killing people as if he was "cutting down weeds". Historical documents note that Muhammad bin Tughluq was cruel and severe not only with non-Muslims, but also with certain sects of Musalmans. He routinely executed "Sayyids" (Shia), "Sufis", "Qalandars", and other Muslim officials. His court historian Ziauddin Barni noted,


title: Tughlaq dynasty

text: Muhammad bin Tughlaq chose the city of Deogiri in present-day Indian state of Maharashtra (renaming it to Daulatabad), as the second administrative capital of the Dehli Sultanate. He ordered a forced migration of the Muslim population of Dehli, including his royal family, the nobles, Syeds, Sheikhs and 'Ulema to settle in Daulatabad. The purpose of transferring the entire Muslim elite to Daulatabad was to enroll them in his mission of world conquest. He saw their role as propagandists who would adapt Islamic religious symbolism to the rhetoric of empire, and that the Sufis could by persuasion bring many of the inhabitants of the Deccan to become Muslim. Tughluq cruelly punished the nobles who were unwilling to move to Daulatabad, seeing their non-compliance of his order as equivalent to rebellion. According to Ferishta, when the Mongols arrived to Punjab, the Sultan returned the elite back to Dehli, although Daulatabad remained as an administrative centre. One result of the transfer of the elite to Daulatabad was the hatred of the nobility to the Sultan, which remained in their minds for a long time. The other result was that he managed to create a stable Muslim elite and result in the growth of the Muslim population of Daulatabad who did not return to Dehli, without which the rise of the Bahmanid kingdom to challenge Vijayanagara would not have been possible. Muhammad bin Tughlaq's adventures in the Deccan region also marked campaigns of destruction and desecration of Hindu and Jain temples, for example the Swayambhu Shiva Temple and the Thousand Pillar Temple.


title: Tughlaq dynasty

text: Revolts against Muhammad bin Tughlaq began in 1327, continued over his reign, and over time the geographical reach of the Sultanate shrunk particularly after 1335. The Vijayanagara Empire originated in southern India as a direct response to attacks from the Delhi Sultanate. The Vijayanagara Empire liberated southern India from the Delhi Sultanate. In 1336 Kapaya Nayak of the Musunuri Nayak defeated the Tughlaq army and reconquered Warangal from the Delhi Sultanate. In 1338 his own nephew rebelled in Malwa, whom he attacked, caught and flayed alive. By 1339, the eastern regions under local Muslim governors and southern parts led by Hindu kings had revolted and declared independence from Delhi Sultanate. Muhammad bin Tughlaq did not have the resources or support to respond to the shrinking kingdom. By 1347, Bahmanid Sultanate had become an independent and competing Muslim kingdom in Deccan region of South Asia.


title: Tughlaq dynasty

text: Muhammad bin Tughlaq was an intellectual, with extensive knowledge of Quran, Fiqh, poetry and other fields. He was deeply suspicious of his kinsmen and "wazirs" (ministers), extremely severe with his opponents, and took decisions that caused economic upheaval. For example, after his expensive campaigns to expand Islamic empire, the state treasury was empty of precious metal coins. So he ordered minting of coins from base metals with face value of silver coins – a decision that failed because ordinary people minted counterfeit coins from base metal they had in their houses.


title: Tughlaq dynasty

text: Ziauddin Barni, a historian in Muhammad bin Tughlaq's court, wrote that the houses of Hindus became a coin mint and people in Hindustan provinces produced fake copper coins worth crores to pay the tribute, taxes and jizya imposed on them. The economic experiments of Muhammad bin Tughlaq resulted in a collapsed economy, and nearly a decade long famine followed that killed numerous people in the countryside. The historian Walford chronicled Delhi and most of India faced severe famines during Muhammad bin Tughlaq's rule, in the years after the base metal coin experiment. Tughlaq introduced token coinage of brass and copper to augment the silver coinage which only led to increasing ease of forgery and loss to the treasury. Also, the people were not willing to trade their gold and silver for the new brass and copper coins. Consequently, the sultan had to withdraw the lot, "buying back both the real and the counterfeit at great expense until mountains of coins had accumulated within the walls of Tughluqabad."


title: Tughlaq dynasty

text: Muhammad bin Tughlaq planned an attack on Khurasan and Irak (Babylon and Persia) as well as China to bring these regions under Sunni Islam. For Khurasan attack, a cavalry of over 300,000 horses were gathered near Delhi, for a year at state treasury's expense, while spies claiming to be from Khurasan collected rewards for information on how to attack and subdue these lands. However, before he could begin the attack on Persian lands in the second year of preparations, the plunder he had collected from Indian subcontinent had emptied, provinces were too poor to support the large army, and the soldiers refused to remain in his service without pay. For the attack on China, Muhammad bin Tughlaq sent 100,000 soldiers, a part of his army, over the Himalayas. However, Hindus closed the passes through the Himalayas and blocked the passage for retreat. Kangra's Prithvi Chand II defeated the army of Muhammad bin Tughluq which was not able to fight in the hills. Nearly all his 100,000 soldiers perished in 1333 and were forced to retreat. The high mountain weather and lack of retreat destroyed that army in the Himalayas. The few soldiers who returned with bad news were executed under orders of the Sultan.


title: Tughlaq dynasty

text: During his reign, state revenues collapsed from his policies. To cover state expenses, Muhammad bin Tughlaq sharply raised taxes on his ever-shrinking empire. Except in times of war, he did not pay his staff from his treasury. Ibn Battuta noted in his memoir that Muhammad bin Tughlaq paid his army, judges ("qadi"), court advisors, wazirs, governors, district officials and others in his service by awarding them the right to force collect taxes on Hindu villages, keep a portion and transfer rest to his treasury. Those who failed to pay taxes were hunted and executed. Muhammad bin Tughlaq died in March 1351 while trying to chase and punish people for rebellion and their refusal to pay taxes in Sindh (now in Pakistan) and Gujarat (now in India).


title: Tughlaq dynasty

text: Historians have attempted to determine the motivations behind Muhammad bin Tughlaq's behavior and his actions. Some state Tughlaq tried to enforce orthodox Islamic observance and practice, promote jihad in South Asia as "al-Mujahid fi sabilillah" ('Warrior for the Path of God') under the influence of Ibn Taymiyyah of Syria. Others suggest insanity.


title: Tughlaq dynasty

text: At the time of Muhammad bin Tughlaq's death, the geographic control of Delhi Sultanate had shrunk to the north of the Narmada river.


title: Tughlaq dynasty

text: After Muhammad bin Tughluq died, a collateral relative, Mahmud Ibn Muhammad, ruled for less than a month. Thereafter, Muhammad bin Tughluq's 45-year-old nephew Firuz Shah Tughlaq replaced him and assumed the throne. His rule lasted 37 years. Firuz Shah was, like his grandfather, of Turko-Indian origins. His Turkic father Sipah Rajab became infatuated with a Hindu princess named Naila. She initially refused to marry him. Her father refused the marriage proposal as well. Sultan Muhammad bin Tughlaq and Sipah Rajab then sent in an army with a demand for one year taxes in advance and a threat of seizure of all property of her family and Dipalpur people. The kingdom was suffering from famines, and could not meet the ransom demand. The princess, after learning about ransom demands against her family and people, offered herself in sacrifice if the army would stop the misery to her people. Sipah Rajab and the Sultan accepted the proposal. Sipah Rajab and Naila were married and Firoz Shah was their first son.


title: Tughlaq dynasty

text: The court historian Ziauddin Barni, who served both Muhammad Tughlaq and the first six years of Firoz Shah Tughlaq, noted that all those who were in service of Muhammad were dismissed and executed by Firoz Shah. In his second book, Barni states that Firuz Shah was the mildest sovereign since the rule of Islam came to Delhi. Muslim soldiers enjoyed the taxes they collected from Hindu villages they had rights over, without having to constantly go to war as in previous regimes. Other court historians such as 'Afif record a number of conspiracies and assassination attempts on Firoz Shah Tughlaq, such as by his first cousin and the daughter of Muhammad bin Tughlaq.


title: Tughlaq dynasty

text: Firoz Shah Tughlaq tried to regain the old kingdom boundary by waging a war with Bengal for 11 months in 1359. However, Bengal did not fall, and remained outside of Delhi Sultanate. Firuz Shah Tughlaq was somewhat weak militarily, mainly because of inept leadership in the army.


title: Tughlaq dynasty

text: An educated sultan, Firoz Shah left a memoir. In it he wrote that he banned torture in practice in Delhi Sultanate by his predecessors, tortures such as amputations, tearing out of eyes, sawing people alive, crushing people's bones as punishment, pouring molten lead into throats, putting people on fire, driving nails into hands and feet, among others. The Sunni Sultan also wrote that he did not tolerate attempts by Rafawiz Shia Muslim and Mahdi sects from proselytizing people into their faith, nor did he tolerate Hindus who tried to rebuild their temples after his armies had destroyed those temples. As punishment, wrote the Sultan, he put many Shias, Mahdi and Hindus to death ("siyasat"). Shams-i Siraj 'Afif, his court historian, also recorded Firoz Shah Tughlaq burning a Hindu Brahmin alive for converting Muslim women to infidelity. In his memoirs, Firoz Shah Tughlaq lists his accomplishments to include converting Hindus to Sunni Islam by announcing an exemption from taxes and jizya for those who convert, and by lavishing new converts with presents and honours. Simultaneously, he raised taxes and jizya, assessing it at three levels, and stopping the practice of his predecessors who had historically exempted all Hindu Brahmins from "jizya" tax. He also vastly expanded the number of slaves in his service and those of amirs (Muslim nobles). Firoz Shah Tughlaq reign was marked by reduction in extreme forms of torture, eliminating favours to select parts of society, but an increased intolerance and persecution of targeted groups. After the death of his heir in 1376 AD, Firuz Shah started strict implementation of Sharia throughout his dominions.


title: Tughlaq dynasty

text: Firuz Shah suffered from bodily infirmities, and his rule was considered by his court historians as more merciful than that of Muhammad bin Tughlaq. When Firuz Shah came to power, India was suffering from a collapsed economy, abandoned villages and towns, and frequent famines. He undertook many infrastructure projects including an irrigation canal connecting Yamuna-Ghaggar and Yamuna-Sutlej rivers, bridges, madrasas (religious schools), mosques and other Islamic buildings. Firuz Shah Tughlaq is credited with patronizing Indo-Islamic architecture, including the installation of lats (ancient Hindu and Buddhist pillars) near mosques. The irrigation canals continued to be in use through the 19th century. After Feroz died in 1388, the Tughlaq dynasty's power continued to fade, and no more able leaders came to the throne. Firoz Shah Tughlaq's death created anarchy and disintegration of kingdom. In the years preceding his death, internecine strife among his descendants had already erupted.


title: Tughlaq dynasty

text: The first civil war broke out in 1384 AD four years before the death of aging Firoz Shah Tughlaq, while the second civil war started in 1394 AD six years after Firoz Shah was dead. The Islamic historians Sirhindi and Bihamadkhani provide the detailed account of this period. These civil wars were primarily between different factions of Sunni Islam aristocracy, each seeking sovereignty and land to tax dhimmis and extract income from resident peasants.


title: Tughlaq dynasty

text: Firuz Shah Tughluq's favorite grandson died in 1376. Thereafter, Firuz Shah sought and followed Sharia more than ever, with the help of his wazirs. He himself fell ill in 1384. By then, Muslim nobility who had installed Firuz Shah Tughluq to power in 1351 had died out, and their descendants had inherited the wealth and rights to extract taxes from non-Muslim peasants. Khan Jahan II, a wazir in Delhi, was the son of Firuz Shah Tughluq's favorite wazir Khan Jahan I, and rose in power after his father died in 1368 AD. The young wazir was in open rivalry with Muhammad Shah, the son of Firuz Shah Tughluq. The wazir's power grew as he appointed more amirs and granted favors. He persuaded the Sultan to name his great-grandson as his heir. Then Khan Jahan II tried to convince Firuz Shah Tughlaq to dismiss his only surviving son. Instead of dismissing his son, the Sultan dismissed the wazir. The crisis that followed led to first civil war, arrest and execution of the wazir, followed by a rebellion and civil war in and around Delhi. Muhammad Shah too was expelled in 1387 AD. The Sultan Firuz Shah Tughluq died in 1388 AD. Tughluq Khan assumed power, but died in conflict. In 1389, Abu Bakr Shah assumed power, but he too died within a year. The civil war continued under Sultan Muhammad Shah, and by 1390 AD, it had led to the seizure and execution of all Muslim nobility who were aligned, or suspected to be aligned to Khan Jahan II.


title: Tughlaq dynasty

text: While the civil war was in progress, predominantly Hindu populations of Himalayan foothills of north India had rebelled, stopped paying Jizya and Kharaj taxes to Sultan's officials. Hindus of southern Doab region of India (now Etawah) joined the rebellion in 1390 AD. Sultan Muhammad Shah attacked Hindus rebelling near Delhi and southern Doab in 1392, with mass executions of peasants, and razing Etawah to the ground. However, by then, most of India had transitioned to a patchwork of smaller Muslim Sultanates and Hindu kingdoms. In 1394, Hindus in Lahore region and northwest South Asia (now Pakistan) had re-asserted self-rule. Muhammad Shah amassed an army to attack them, with his son Humayun Khan as the commander-in-chief. While preparations were in progress in Delhi in January 1394, Sultan Muhammad Shah died. His son, Humayun Khan assumed power but was murdered within two months. The brother of Humayun Khan, Nasir-al-din Mahmud Shah assumed power – but he enjoyed little support from Muslim nobility, the wazirs and amirs. The Sultanate had lost command over almost all eastern and western provinces of already shrunken Sultanate. Within Delhi, factions of Muslim nobility formed by October 1394 AD, triggering the second civil war.


title: Tughlaq dynasty

text: Tartar Khan installed a second Sultan, Nasir-al-din Nusrat Shah in Firozabad, few kilometers from the first Sultan seat of power in late 1394. The two Sultans claimed to be rightful ruler of South Asia, each with a small army, controlled by a coterie of Muslim nobility. Battles occurred every month, duplicity and switching of sides by amirs became commonplace, and the civil war between the two Sultan factions continued through 1398, till the invasion by Timur.


title: Tughlaq dynasty

text: The lowest point for the dynasty came in 1398, when Turco-Mongol invader, Timur (Tamerlane) defeated four armies of the Sultanate. During the invasion, Sultan Mahmud Khan fled before Tamerlane entered Delhi. For eight days Delhi was plundered, its population massacred, and over 100,000 prisoners were killed as well.


title: Tughlaq dynasty

text: The capture of the Delhi Sultanate was one of Timur's greatest victories, as at that time, Delhi was one of the richest cities in the world. After Delhi fell to Timur's army, uprisings by its citizens against the Turkic-Mongols began to occur, causing a retaliatory bloody massacre within the city walls. After three days of citizens uprising within Delhi, it was said that the city reeked of the decomposing bodies of its citizens with their heads being erected like structures and the bodies left as food for the birds by Timur's soldiers. Timur's invasion and destruction of Delhi continued the chaos that was still consuming India, and the city would not be able to recover from the great loss it suffered for almost a century.


title: Tughlaq dynasty

text: It is believed that before his departure, Timur appointed Khizr Khan, the future founder of the succeeding Sayyid dynasty, as his viceroy at Delhi. Initially, Khizr Khan could only establish his control over Multan, Dipalpur and parts of Sindh. Soon he started his campaign against the Tughlaq dynasty, and entered Delhi victoriously on 6 June 1414.


title: Tughlaq dynasty

text: Ibn Battuta, the Moroccan Muslim traveller, left extensive notes on Tughlaq dynasty in his travel memoirs. Ibn Battuta arrived in India through the mountains of Afghanistan, in 1334, at the height of Tughlaq dynasty's geographic empire. On his way, he learnt that Sultan Muhammad Tughluq liked gifts from his visitors, and gave to his visitors gifts of far greater value in return. Ibn Battuta met Muhammad bin Tughluq, presenting him with gifts of arrows, camels, thirty horses, slaves and other goods. Muhammad bin Tughlaq responded by giving Ibn Battuta with a welcoming gift of 2,000 silver dinars, a furnished house and the job of a judge with an annual salary of 5,000 silver dinars that Ibn Battuta had the right to keep by collecting taxes from two and a half Hindu villages near Delhi.


title: Tughlaq dynasty

text: In his memoirs about Tughlaq dynasty, Ibn Batutta recorded the history of Qutb complex which included Quwat al-Islam Mosque and the Qutb Minar. He noted the seven-year famine from 1335 AD, which killed thousands upon thousands of people near Delhi, while the Sultan was busy attacking rebellions. He was tough both against non-Muslims and Muslims. For example,


title: Tughlaq dynasty

text: In Tughlaq dynasty, the punishments were extended even to Muslim religious figures who were suspected rebellion. For example, Ibn Battuta mentions Sheikh Shinab al-Din, who was imprisoned and tortured as follows:


title: Tughlaq dynasty

text: Ibn Batutta wrote that Sultan's officials demanded bribes from him while he was in Delhi, as well as deducted 10% of any sums that Sultan gave to him. Towards the end of his stay in Tughluq dynasty court, Ibn Battuta came under suspicion for his friendship with a Sufi Muslim holy man. Both Ibn Battuta and the Sufi Muslim were arrested. While Ibn Battuta was allowed to leave India, the Sufi Muslim was killed as follows according to Ibn Battuta during the period he was under arrest:


title: Tughlaq dynasty

text: Each military campaign and raid on non-Muslim kingdoms yielded loot and seizure of slaves. Additionally, the Sultans patronized a market () for trade of both foreign and Indian slaves. This market flourished under the reign of all Sultans of Tughlaq dynasty, particularly Ghiyasuddin Tughlaq, Muhammad Tughlaq and Firoz Tughlaq.


title: Tughlaq dynasty

text: Ibn Battuta's memoir records that he fathered a child each with two slave girls, one from Greece and one he purchased during his stay in Delhi Sultanate. This was in addition to the daughter he fathered by marrying a Muslim woman in India. Ibn Battuta also records that Muhammad Tughlaq sent along with his emissaries, both slave boys and slave girls as gifts to other countries such as China.


title: Tughlaq dynasty

text: The Tughlaq dynasty experienced many revolts by Muslim nobility, particularly during Muhammad bin Tughlaq but also during other rulers such as Firoz Shah Tughlaq.


title: Tughlaq dynasty

text: The Tughlaqs had attempted to manage their expanded empire by appointing family members and Muslim aristocracy as na'ib () of Iqta' (farming provinces, ) under contract. The contract would require that the na'ib shall have the right to force collect taxes from non-Muslim peasants and local economy, deposit a fixed sum of tribute and taxes to Sultan's treasury on a periodic basis. The contract allowed the na'ib to keep a certain amount of taxes they collected from peasants as their income, but the contract required any excess tax and seized property collected from non-Muslims to be split between na'ib and Sultan in a 20:80 ratio (Firuz Shah changed this to 80:20 ratio). The na'ib had the right to keep soldiers and officials to help extract taxes. After contracting with Sultan, the na'ib would enter into subcontracts with Muslim amirs and army commanders, each granted the right over certain villages to force collect or seize produce and property from dhimmis.


title: Tughlaq dynasty

text: This system of tax extraction from peasants and sharing among Muslim nobility led to rampant corruption, arrests, execution and rebellion. For example, in the reign of Firoz Shah Tughlaq, a Muslim noble named Shamsaldin Damghani entered into a contract over the iqta' of Gujarat, promising enormous sums of annual tribute while entering the contract in 1377 AD. He then attempted to force collect the amount deploying his coterie of Muslim amirs, but failed. Even the amount he did manage to collect, he paid nothing to Delhi. Shamsaldin Damghani and Muslim nobility of Gujarat then declared rebellion and separation from Delhi Sultanate. However, the soldiers and peasants of Gujarat refused to fight the war for the Muslim nobility. Shamsaldin Damghani was killed. During the reign of Muhammad Shah Tughlaq, similar rebellions were very common. His own nephew rebelled in Malwa in 1338 AD; Muhammad Shah Tughlaq attacked Malwa, seized his nephew, and then flayed him alive in public.


title: Tughlaq dynasty

text: The provinces of Deccan, Bengal, Sindh and Multhan had become independent during the reign of Muhammad Bin Tughlaq. The invasion of Timur further weakened the Tughlaq empire and allowed several regional chiefs to become independent, resulting in the formation of the sultanates of Gujarat, Malwa and Jaunpur. The Rajput states also expelled the governor of Ajmer and asserted control over Rajputana. The Tughlaq power continued to decline until they were finally overthrown by their former governor of Multhan, Khizr Khan. Resulting in the rise of the Sayyid Dynasty as the new rulers of the Delhi Sultanate.


title: Tughlaq dynasty

text: The Sultans of Tughlaq dynasty, particularly Firoz Shah Tughlaq, patronized many construction projects and are credited with the development of Indo-Islamic architecture.


title: Accelerometer

text: An accelerometer is a tool that measures proper acceleration. Proper acceleration is the acceleration (the rate of change of velocity) of a body in its own instantaneous rest frame; this is different from coordinate acceleration, which is acceleration in a fixed coordinate system. For example, an accelerometer at rest on the surface of the Earth will measure an acceleration due to Earth's gravity, straight upwards (by definition) of g ≈ 9.81 m/s. By contrast, accelerometers in free fall (falling toward the center of the Earth at a rate of about 9.81 m/s) will measure zero.


title: Accelerometer

text: Accelerometers have many uses in industry and science. Highly sensitive accelerometers are used in inertial navigation systems for aircraft and missiles. Vibration in rotating machines is monitored by accelerometers. They are used in tablet computers and digital cameras so that images on screens are always displayed upright. In unmanned aerial vehicles, accelerometers help to stabilise flight.


title: Accelerometer

text: When two or more accelerometers are coordinated with one another, they can measure differences in proper acceleration, particularly gravity, over their separation in space—that is, the gradient of the gravitational field. Gravity gradiometry is useful because absolute gravity is a weak effect and depends on the local density of the Earth, which is quite variable.


title: Accelerometer

text: Single- and multi-axis accelerometers can detect both the magnitude and the direction of the proper acceleration, as a vector quantity, and can be used to sense orientation (because the direction of weight changes), coordinate acceleration, vibration, shock, and falling in a resistive medium (a case in which the proper acceleration changes, increasing from zero). Micromachined microelectromechanical systems (MEMS) accelerometers are increasingly present in portable electronic devices and video-game controllers, to detect changes in the positions of these devices.


title: Accelerometer

text: An accelerometer measures proper acceleration, which is the acceleration it experiences relative to freefall and is the acceleration felt by people and objects. Put another way, at any point in spacetime the equivalence principle guarantees the existence of a local inertial frame, and an accelerometer measures the acceleration relative to that frame. Such accelerations are popularly denoted g-force; i.e., in comparison to standard gravity.


title: Accelerometer

text: An accelerometer at rest relative to the Earth's surface will indicate approximately 1 g "upwards" because the Earth's surface exerts a normal force upwards relative to the local inertial frame (the frame of a freely falling object near the surface). To obtain the acceleration due to motion with respect to the Earth, this "gravity offset" must be subtracted and corrections made for effects caused by the Earth's rotation relative to the inertial frame.


title: Accelerometer

text: The reason for the appearance of a gravitational offset is Einstein's equivalence principle, which states that the effects of gravity on an object are indistinguishable from acceleration. When held fixed in a gravitational field by, for example, applying a ground reaction force or an equivalent upward thrust, the reference frame for an accelerometer (its own casing) accelerates upwards with respect to a free-falling reference frame. The effects of this acceleration are indistinguishable from any other acceleration experienced by the instrument so that an accelerometer cannot detect the difference between sitting in a rocket on the launch pad, and being in the same rocket in deep space while it uses its engines to accelerate at 1 g. For similar reasons, an accelerometer will read "zero" during any type of free fall. This includes use in a coasting spaceship in deep space far from any mass, a spaceship orbiting the Earth, an airplane in a parabolic "zero-g" arc, or any free-fall in a vacuum. Another example is free-fall at a sufficiently high altitude that atmospheric effects can be neglected.


title: Accelerometer

text: However, this does not include a (non-free) fall in which air resistance produces drag forces that reduce the acceleration until constant terminal velocity is reached. At terminal velocity, the accelerometer will indicate 1 g acceleration upwards. For the same reason a skydiver, upon reaching terminal velocity, does not feel as though he or she were in "free-fall", but rather experiences a feeling similar to being supported (at 1 g) on a "bed" of uprushing air.


title: Accelerometer

text: Acceleration is quantified in the SI unit metres per second per second (m/s), in the cgs unit gal (Gal), or popularly in terms of standard gravity ("g").


title: Accelerometer

text: For the practical purpose of finding the acceleration of objects with respect to the Earth, such as for use in an inertial navigation system, a knowledge of local gravity is required. This can be obtained either by calibrating the device at rest, or from a known model of gravity at the approximate current position.


title: Accelerometer

text: Conceptually, an accelerometer is a damped mass, a proof mass, on a spring. When the accelerometer experiences an acceleration, the mass is moved to the point that the spring can push (accelerate) the mass at the same speed as the casing. The measurement of the spring's compression measures the acceleration. The system is damped so that oscillations (wiggles) of the mass and spring do not affect the needed measurements. Because of the damping, accelerometers always respond in different ways to different frequencies of acceleration. This is called the "frequency response."


title: Accelerometer

text: Many animals have sensory organs to detect acceleration, especially gravity. In these, the proof mass is usually one or more crystals of calcium carbonate otoliths (Latin for "ear stone") or statoconia, acting against a bed of hairs connected to neurons. The hairs form the springs, with the neurons as sensors. The damping is usually by a fluid. Many vertebrates, including humans, have these structures in their inner ears. Most invertebrates have similar organs, but not as part of their hearing organs. These are called statocysts.


title: Accelerometer

text: Mechanical accelerometers are often designed so that an electronic circuit senses a small amount of motion, then pushes on the proof mass with some type of linear motor to keep the proof mass from moving far. The motor might be an electromagnet or in very small accelerometers, electrostatic. Since the circuit's electronic behavior can be carefully designed, and the proof mass does not move far, these designs can be very stable (i.e. they do not oscillate), very linear with a controlled frequency response. (This is called servo mode design.)


title: Accelerometer

text: In mechanical accelerometers, measurement is often electrical, piezoelectric, piezoresistive or capacitive. Piezoelectric accelerometers use piezoceramic sensors (e.g. lead zirconate titanate) or single crystals (e.g. quartz, tourmaline). They are unmatched in high frequency measurements, low packaged weight, and resistance to high temperatures. Piezoresistive accelerometers resist shock (very high accelerations) better. Capacitive accelerometers typically use a silicon micro-machined sensing element. They measure low frequencies well.


title: Accelerometer

text: Modern mechanical accelerometers are often small "micro-electro-mechanical systems" (MEMS), and are often very simple MEMS devices, consisting of little more than a cantilever beam with a proof mass (also known as "seismic mass"). Damping results from the residual gas sealed in the device. As long as the Q-factor is not too low, damping does not result in a lower sensitivity.


title: Accelerometer

text: Under the influence of external accelerations, the proof mass deflects from its neutral position. This deflection is measured in an analog or digital manner. Most commonly, the capacitance between a set of fixed beams and a set of beams attached to the proof mass is measured. This method is simple, reliable, and inexpensive. Integrating piezoresistors in the springs to detect spring deformation, and thus deflection, is a good alternative, although a few more process steps are needed during the fabrication sequence. For very high sensitivities quantum tunnelling is also used; this requires a dedicated process making it very expensive. Optical measurement has been demonstrated in laboratory devices.


title: Accelerometer

text: Another MEMS-based accelerometer is a thermal (or convective) accelerometer. It contains a small heater in a very small dome. This heats the air or other fluid inside the dome. The thermal bubble acts as the proof mass. An accompanying temperature sensor (like a thermistor; or thermopile) in the dome measures the temperature in one location of the dome. This measures the location of the heated bubble within the dome. When the dome is accelerated, the colder, higher density fluid pushes the heated bubble. The measured temperature changes. The temperature measurement is interpreted as acceleration. The fluid provides the damping. Gravity acting on the fluid provides the spring. Since the proof mass is very lightweight gas, and not held by a beam or lever, thermal accelerometers can survive high shocks. Another variation uses a wire to both heat the gas and detect the change in temperature. The change of temperature changes the resistance of the wire. A two dimensional accelerometer can be economically constructed with one dome, one bubble and two measurement devices.


title: Accelerometer

text: Most micromechanical accelerometers operate "in-plane", that is, they are designed to be sensitive only to a direction in the plane of the die. By integrating two devices perpendicularly on a single die a two-axis accelerometer can be made. By adding another "out-of-plane" device, three axes can be measured. Such a combination may have much lower misalignment error than three discrete models combined after packaging.


title: Accelerometer

text: Micromechanical accelerometers are available in a wide variety of measuring ranges, reaching up to thousands of "g"s. The designer must compromise between sensitivity and the maximum acceleration that can be measured.


title: Accelerometer

text: Accelerometers can be used to measure vibration on cars, machines, buildings, process control systems and safety installations. They can also be used to measure seismic activity, inclination, machine vibration, dynamic distance and speed with or without the influence of gravity. Applications for accelerometers that measure gravity, wherein an accelerometer is specifically configured for use in gravimetry, are called gravimeters.


title: Accelerometer

text: Notebook computers equipped with accelerometers can contribute to the "Quake-Catcher Network" (QCN), a BOINC project aimed at scientific research of earthquakes.


title: Accelerometer

text: Accelerometers are also increasingly used in the biological sciences. High frequency recordings of bi-axial or tri-axial acceleration allows the discrimination of behavioral patterns while animals are out of sight. Furthermore, recordings of acceleration allow researchers to quantify the rate at which an animal is expending energy in the wild, by either determination of limb-stroke frequency or measures such as overall dynamic body acceleration Such approaches have mostly been adopted by marine scientists due to an inability to study animals in the wild using visual observations, however an increasing number of terrestrial biologists are adopting similar approaches. For example, accelerometers have been used to study flight energy expenditure of Harris's Hawk ("Parabuteo unicinctus"). Researchers are also using smartphone accelerometers to collect and extract mechano-biological descriptors of resistance exercise. Increasingly, researchers are deploying accelerometers with additional technology, such as cameras or microphones, to better understand animal behaviour in the wild (for example, hunting behaviour of Canada lynx).


title: Accelerometer

text: Accelerometers are also used for machinery health monitoring to report the vibration and its changes in time of shafts at the bearings of rotating equipment such as turbines, pumps, fans, rollers, compressors, or bearing fault


title: Accelerometer

text: which, if not attended to promptly, can lead to costly repairs. Accelerometer vibration data allows the user to monitor machines and detect these faults before the rotating equipment fails completely.


title: Accelerometer

text: Accelerometers are used to measure the motion and vibration of a structure that is exposed to dynamic loads. Dynamic loads originate from a variety of sources including:


title: Accelerometer

text: Under structural applications, measuring and recording how a structure dynamically responds to these inputs is critical for assessing the safety and viability of a structure. This type of monitoring is called Health Monitoring, which usually involves other types of instruments, such as displacement sensors -Potentiometers, LVDTs, etc.- deformation sensors -Strain Gauges, Extensometers-, load sensors -Load Cells, Piezo-Electric Sensors- among others.


title: Accelerometer

text: Zoll's AED Plus uses CPR-D•padz which contain an accelerometer to measure the depth of CPR chest compressions.


title: Accelerometer

text: Within the last several years, several companies have produced and marketed sports watches for runners that include footpods, containing accelerometers to help determine the speed and distance for the runner wearing the unit.


title: Accelerometer

text: In Belgium, accelerometer-based step counters are promoted by the government to encourage people to walk a few thousand steps each day.


title: Accelerometer

text: It has been suggested to build football helmets with accelerometers in order to measure the impact of head collisions.


title: Accelerometer

text: Accelerometers have been used to calculate gait parameters, such as stance and swing phase. This kind of sensor can be used to measure or monitor people.


title: Accelerometer

text: An inertial navigation system is a navigation aid that uses a computer and motion sensors (accelerometers) to continuously calculate via dead reckoning the position, orientation, and velocity (direction and speed of movement) of a moving object without the need for external references. Other terms used to refer to inertial navigation systems or closely related devices include inertial guidance system, inertial reference platform, and many other variations.


title: Accelerometer

text: An accelerometer alone is unsuitable to determine changes in altitude over distances where the vertical decrease of gravity is significant, such as for aircraft and rockets. In the presence of a gravitational gradient, the calibration and data reduction process is numerically unstable.


title: Accelerometer

text: Accelerometers are also being used in Intelligent Compaction rollers. Accelerometers are used alongside gyroscopes in inertial navigation systems.


title: Accelerometer

text: One of the most common uses for MEMS accelerometers is in airbag deployment systems for modern automobiles. In this case, the accelerometers are used to detect the rapid negative acceleration of the vehicle to determine when a collision has occurred and the severity of the collision. Another common automotive use is in electronic stability control systems, which use a lateral accelerometer to measure cornering forces. The widespread use of accelerometers in the automotive industry has pushed their cost down dramatically. Another automotive application is the monitoring of noise, vibration, and harshness (NVH), conditions that cause discomfort for drivers and passengers and may also be indicators of mechanical faults.


title: Accelerometer

text: Modern electronic accelerometers are used in remote sensing devices intended for the monitoring of active volcanoes to detect the motion of magma.


title: Accelerometer

text: Accelerometers are increasingly being incorporated into personal electronic devices to detect the orientation of the device, for example, a display screen.


title: Accelerometer

text: A "free-fall sensor" (FFS) is an accelerometer used to detect if a system has been dropped and is falling. It can then apply safety measures such as parking the head of a hard disk to prevent a head crash and resulting data loss upon impact. This device is included in the many common computer and consumer electronic products that are produced by a variety of manufacturers. It is also used in some data loggers to monitor handling operations for shipping containers. The length of time in free fall is used to calculate the height of drop and to estimate the shock to the package.


title: Accelerometer

text: Some smartphones, digital audio players and personal digital assistants contain accelerometers for user interface control; often the accelerometer is used to present landscape or portrait views of the device's screen, based on the way the device is being held. Apple has included an accelerometer in every generation of iPhone, iPad, and iPod touch, as well as in every iPod nano since the 4th generation. Along with orientation view adjustment, accelerometers in mobile devices can also be used as pedometers, in conjunction with specialized applications.


title: Accelerometer

text: Automatic Collision Notification (ACN) systems also use accelerometers in a system to call for help in event of a vehicle crash. Prominent ACN systems include OnStar AACN service, Ford Link's 911 Assist, Toyota's Safety Connect, Lexus Link, or BMW Assist. Many accelerometer-equipped smartphones also have ACN software available for download. ACN systems are activated by detecting crash-strength accelerations.


title: Accelerometer

text: Accelerometers are used in vehicle Electronic stability control systems to measure the vehicle's actual movement. A computer compares the vehicle's actual movement to the driver's steering and throttle input. The stability control computer can selectively brake individual wheels and/or reduce engine power to minimize the difference between driver input and the vehicle's actual movement. This can help prevent the vehicle from spinning or rolling over.


title: Accelerometer

text: Some pedometers use an accelerometer to more accurately measure the number of steps taken and distance traveled than a mechanical sensor can provide.


title: Accelerometer

text: Nintendo's Wii video game console uses a controller called a Wii Remote that contains a three-axis accelerometer and was designed primarily for motion input. Users also have the option of buying an additional motion-sensitive attachment, the Nunchuk, so that motion input could be recorded from both of the user's hands independently. Is also used on the Nintendo 3DS system.


title: Accelerometer

text: The Sony PlayStation 3 uses the DualShock 3 remote which uses a three axis accelerometer that can be used to make steering more realistic in racing games, such as "MotorStorm" and "Burnout Paradise".


title: Accelerometer

text: The Nokia 5500 sport features a 3D accelerometer that can be accessed from software. It is used for step recognition (counting) in a sport application, and for tap gesture recognition in the user interface. Tap gestures can be used for controlling the music player and the sport application, for example to change to next song by tapping through clothing when the device is in a pocket. Other uses for accelerometer in Nokia phones include Pedometer functionality in Nokia Sports Tracker. Some other devices provide the tilt sensing feature with a cheaper component, which is not a true accelerometer.


title: Accelerometer

text: Sleep phase alarm clocks use accelerometric sensors to detect movement of a sleeper, so that it can wake the person when he/she is not in REM phase, in order to awaken the person more easily.


title: Accelerometer

text: A microphone or eardrum is a membrane that responds to oscillations in air pressure. These oscillations cause acceleration, so accelerometers can be used to record sound. A 2012 study found that voices can be detected by smartphone accelerometers in 93% of typical daily situations.


title: Accelerometer

text: Conversely, carefully designed sounds can cause accelerometers to report false data. One study tested 20 models of (MEMS) smartphone accelerometers and found that a majority were susceptible to this attack.


title: Accelerometer

text: A number of 21st-century devices use accelerometers to align the screen depending on the direction the device is held (e.g., switching between portrait and landscape modes). Such devices include many tablet PCs and some smartphones and digital cameras. The Amida Simputer, a handheld Linux device launched in 2004, was the first commercial handheld to have a built-in accelerometer. It incorporated many gesture-based interactions using this accelerometer, including page-turning, zoom-in and zoom-out of images, change of portrait to landscape mode, and many simple gesture-based games.


title: Accelerometer

text: As of January 2009, almost all new mobile phones and digital cameras contain at least a tilt sensor and sometimes an accelerometer for the purpose of auto image rotation, motion-sensitive mini-games, and correcting shake when taking photographs.


title: Accelerometer

text: Camcorders use accelerometers for image stabilization, either by moving optical elements to adjust the light path to the sensor to cancel out unintended motions or digitally shifting the image to smooth out detected motion. Some stills cameras use accelerometers for anti-blur capturing. The camera holds off capturing the image when the camera is moving. When the camera is still (if only for a millisecond, as could be the case for vibration), the image is captured. An example of the application of this technology is the Glogger VS2, a phone application which runs on Symbian based phones with accelerometers such as the Nokia N96. Some digital cameras contain accelerometers to determine the orientation of the photo being taken and also for rotating the current picture when viewing.


title: Accelerometer

text: Many laptops feature an accelerometer which is used to detect drops. If a drop is detected, the heads of the hard disk are parked to avoid data loss and possible head or disk damage by the ensuing shock.


title: Accelerometer

text: A gravimeter or gravitometer, is an instrument used in gravimetry for measuring the local gravitational field. A gravimeter is a type of accelerometer, except that accelerometers are susceptible to all vibrations including noise, that cause oscillatory accelerations. This is counteracted in the gravimeter by integral vibration isolation and signal processing. Though the essential principle of design is the same as in accelerometers, gravimeters are typically designed to be much more sensitive than accelerometers in order to measure very tiny changes within the Earth's gravity, of 1 "g". In contrast, other accelerometers are often designed to measure 1000 "g" or more, and many perform multi-axial measurements. The constraints on temporal resolution are usually less for gravimeters, so that resolution can be increased by processing the output with a longer "time constant".


title: Accelerometer

text: Accelerometer data, which can be accessed by third-party apps without user permission in many mobile devices, has been used to infer rich information about users based on the recorded motion patterns (e.g., driving behavior, level of intoxication, age, gender, touchscreen inputs, geographic location). If done without a user's knowledge or consent, this is referred to as an inference attack. Additionally, millions of smartphones could be vulnerable to software cracking via accelerometers.


title: Base (chemistry)

text: In chemistry, there are three definitions in common use of the word base, known as Arrhenius bases, Brønsted bases, and Lewis bases. All definitions agree that bases are substances that react with acids, as originally proposed by G.-F. Rouelle in the mid-18th century.


title: Base (chemistry)

text: In 1884, Svante Arrhenius proposed that a base is a substance which dissociates in aqueous solution to form Hydroxide ions OH. These ions can react with hydrogen ions (H according to Arrhenius) from the dissociation of acids to form water in an acid–base reaction. A base was therefore a metal hydroxide such as NaOH or Ca(OH). Such aqueous hydroxide solutions were also described by certain characteristic properties. They are slippery to the touch, can taste bitter and change the color of pH indicators (e.g., turn red litmus paper blue).


title: Base (chemistry)

text: In water, by altering the autoionization equilibrium, bases yield solutions in which the hydrogen ion activity is lower than it is in pure water, i.e., the water has a pH higher than 7.0 at standard conditions. A soluble base is called an alkali if it contains and releases OH ions quantitatively. Metal oxides, hydroxides, and especially alkoxides are basic, and conjugate bases of weak acids are weak bases.


title: Base (chemistry)

text: Bases and acids are seen as chemical opposites because the effect of an acid is to increase the hydronium (HO) concentration in water, whereas bases reduce this concentration. A reaction between aqueous solutions of an acid and a base is called neutralization, producing a solution of water and a salt in which the salt separates into its component ions. If the aqueous solution is saturated with a given salt solute, any additional such salt precipitates out of the solution.


title: Base (chemistry)

text: In the more general Brønsted–Lowry acid–base theory (1923), a base is a substance that can accept hydrogen cations (H)—otherwise known as protons. This does include aqueous hydroxides since OH does react with H to form water, so that Arrhenius bases are a subset of Brønsted bases. However, there are also other Brønsted bases which accept protons, such as aqueous solutions of ammonia (NH) or its organic derivatives (amines). These bases do not contain a hydroxide ion but nevertheless react with water, resulting in an increase in the concentration of hydroxide ion. Also, some non-aqueous solvents contain Brønsted bases which react with solvated protons. For example in liquid ammonia, NH is the basic ion species which accepts protons from NH, the acidic species in this solvent.


title: Base (chemistry)

text: G. N. Lewis realized that water, ammonia, and other bases can form a bond with a proton due to the unshared pair of electrons that the bases possess. In the Lewis theory, a base is an electron pair donor which can share a pair of electrons with an electron acceptor which is described as a Lewis acid. The Lewis theory is more general than the Brønsted model because the Lewis acid is not necessarily a proton, but can be another molecule (or ion) with a vacant low-lying orbital which can accept a pair of electrons. One notable example is boron trifluoride (BF).


title: Base (chemistry)

text: Some other definitions of both bases and acids have been proposed in the past, but are not commonly used today.


title: Base (chemistry)

text: The following reaction represents the general reaction between a base (B) and water to produce a conjugate acid (BH) and a conjugate base (OH):<chem display="block">{B}_{(aq)} + {H2O}_{(l)} <=> {BH+}_{(aq)} + {OH- }_{(aq)}</chem>The equilibrium constant, K, for this reaction can be found using the following general equation:


title: Base (chemistry)

text: In this equation, the base (B) and the extremely strong base (the conjugate base OH) compete for the proton. As a result, bases that react with water have relatively small equilibrium constant values. The base is weaker when it has a lower equilibrium constant value.


title: Base (chemistry)

text: Bases react with acids to neutralize each other at a fast rate both in water and in alcohol. When dissolved in water, the strong base sodium hydroxide ionizes into hydroxide and sodium ions:


title: Base (chemistry)

text: If equal quantities of NaOH and HCl are dissolved, the base and the acid neutralize exactly, leaving only NaCl, effectively table salt, in solution.


title: Base (chemistry)

text: Weak bases, such as baking soda or egg white, should be used to neutralize any acid spills. Neutralizing acid spills with strong bases, such as sodium hydroxide or potassium hydroxide, can cause a violent exothermic reaction, and the base itself can cause just as much damage as the original acid spill.


title: Base (chemistry)

text: Bases are generally compounds that can neutralize an amount of acid. Both sodium carbonate and ammonia are bases, although neither of these substances contains groups. Both compounds accept H when dissolved in protic solvents such as water:


title: Base (chemistry)

text: A base is also defined as a molecule that has the ability to accept an electron pair bond by entering another atom's valence shell through its possession of one electron pair. There are a limited number of elements that have atoms with the ability to provide a molecule with basic properties. Carbon can act as a base as well as nitrogen and oxygen. Fluorine and sometimes rare gases possess this ability as well. This occurs typically in compounds such as butyl lithium, alkoxides, and metal amides such as sodium amide. Bases of carbon, nitrogen and oxygen without resonance stabilization are usually very strong, or superbases, which cannot exist in a water solution due to the acidity of water. Resonance stabilization, however, enables weaker bases such as carboxylates; for example, sodium acetate is a weak base.


title: Base (chemistry)

text: A strong base is a basic chemical compound that can remove a proton (H) from (or "deprotonate") a molecule of even a very weak acid (such as water) in an acid–base reaction. Common examples of strong bases include hydroxides of alkali metals and alkaline earth metals, like NaOH and , respectively. Due to their low solubility, some bases, such as alkaline earth hydroxides, can be used when the solubility factor is not taken into account. One advantage of this low solubility is that "many antacids were suspensions of metal hydroxides such as aluminium hydroxide and magnesium hydroxide." These compounds have low solubility and have the ability to stop an increase in the concentration of the hydroxide ion, preventing the harm of the tissues in the mouth, oesophagus, and stomach. As the reaction continues and the salts dissolve, the stomach acid reacts with the hydroxide produced by the suspensions. Strong bases hydrolyze in water almost completely, resulting in the leveling effect." In this process, the water molecule combines with a strong base, due to the water's amphoteric ability; and, a hydroxide ion is released. Very strong bases can even deprotonate very weakly acidic C–H groups in the absence of water. Here is a list of several strong bases:


title: Base (chemistry)

text: The cations of these strong bases appear in the first and second groups of the periodic table (alkali and earth alkali metals). Tetraalkylated ammonium hydroxides are also strong bases since they dissociate completely in water. Guanidine is a special case of a species that is exceptionally stable when protonated, analogously to the reason that makes perchloric acid and sulfuric acid very strong acids.


title: Base (chemistry)

text: Acids with a p"K" of more than about 13 are considered very weak, and their conjugate bases are strong bases.


title: Base (chemistry)

text: Group 1 salts of carbanions, amide ions, and hydrides tend to be even stronger bases due to the extreme weakness of their conjugate acids, which are stable hydrocarbons, amines, and dihydrogen. Usually, these bases are created by adding pure alkali metals such as sodium into the conjugate acid. They are called "superbases", and it is impossible to keep them in aqueous solutions because they are stronger bases than the hydroxide ion (See the leveling effect.) For example, the ethoxide ion (conjugate base of ethanol) undergoes this reaction quantitatively in presence of water.


title: Base (chemistry)

text: A weak base is one which does not fully ionize in an aqueous solution, or in which protonation is incomplete. For example, ammonia transfers a proton to water according to the equation


title: Base (chemistry)

text: The equilibrium constant for this reaction at 25 °C is 1.8 x 10, such that the extent of reaction or degree of ionization is quite small.


title: Base (chemistry)

text: A Lewis base or "electron-pair donor" is a molecule with one or more high-energy lone pairs of electrons which can be shared with a low-energy vacant orbital in an acceptor molecule to form an adduct. In addition to H, possible "electron-pair acceptors" (Lewis acids) include neutral molecules such as BF and high oxidation state metal ions such as Ag, Fe and Mn. Adducts involving metal ions are usually described as coordination complexes.


title: Base (chemistry)

text: According to the original formulation of Lewis, when a neutral base forms a bond with a neutral acid, a condition of electric stress occurs. The acid and the base share the electron pair that formerly belonged to the base. As a result, a high dipole moment is created, which can only be decreased to zero by rearranging the molecules.


title: Base (chemistry)

text: Depending on a solid surface's ability to successfully form a conjugate base by absorbing an electrically neutral acid, basic strength of the surface is determined. The "number of basic sites per unit surface area of the solid" is used to express how much basic strength is found on a solid base catalyst. Scientists have developed two methods to measure the amount of basic sites: one, titration with benzoic acid using indicators and gaseous acid adsorption. A solid with enough basic strength will absorb an electrically neutral acidic indicator and cause the acidic indicator's color to change to the color of its conjugate base. When performing the gaseous acid adsorption method, nitric oxide is used. The basic sites are then determined by calculating the amount of carbon dioxide that is absorbed.


title: Base (chemistry)

text: Basic substances can be used as insoluble heterogeneous catalysts for chemical reactions. Some examples are metal oxides such as magnesium oxide, calcium oxide, and barium oxide as well as potassium fluoride on alumina and some zeolites. Many transition metals make good catalysts, many of which form basic substances. Basic catalysts are used for hydrogenation, the migration of double bonds, in the Meerwein-Ponndorf-Verley reduction, the Michael reaction, and many others. Both CaO and BaO can be highly active catalysts if they are heated to high temperatures.


title: Base (chemistry)

text: Bases with only one ionizable hydroxide (OH) ion per formula unit are called monoprotic since they can accept one proton (H). Bases with more than one OH- per formula unit are polyprotic.


title: Base (chemistry)

text: The number of ionizable hydroxide (OH) ions present in one formula unit of a base is also called the acidity of the base. On the basis of acidity bases can be classified into three types: monoacidic, diacidic and triacidic.


title: Base (chemistry)

text: When one molecule of a base via complete ionization produces one hydroxide ion, the base is said to be a monoacidic or monoprotic base. Examples of monoacidic bases are:


title: Base (chemistry)

text: When one molecule of base via complete ionization produces two hydroxide ions, the base is said to be diacidic or diprotic. Examples of diacidic bases are:


title: Base (chemistry)

text: Barium hydroxide, magnesium hydroxide, calcium hydroxide, zinc hydroxide, iron(II) hydroxide, tin(II) hydroxide, lead(II) hydroxide, copper(II) hydroxide, etc.


title: Base (chemistry)

text: When one molecule of base via complete ionization produces three hydroxide ions, the base is said to be triacidic or triprotic. Examples of triacidic bases are:


title: Jim Watkins (businessman)

text: James Arthur Watkins (born November 1963) is an American businessman, QAnon conspiracy theorist, and the operator of the imageboard website 8chan/8kun and textboard website 5channel. Watkins founded the company N.T. Technology in the 1990s to support a Japanese pornography website he created while he was enlisted in the United States Army. After leaving the Army to focus on the company, Watkins moved to the Philippines. In February 2014, Watkins became the operator of 2channel after he seized it from its creator and original owner, Hiroyuki Nishimura. He began providing domain and hosting services to 8chan later that year and became the site's official owner and operator by year's end.


title: Jim Watkins (businessman)

text: It has been widely speculated by journalists and conspiracy theory researchers that Watkins or his son, Ron Watkins, either know the identity of, or are themselves, "Q", the person or group of people behind the QAnon conspiracy theory.


title: Jim Watkins (businessman)

text: James Arthur Watkins was born in Dayton, Washington, and grew up on a family farm in Mukilteo, Washington. His mother worked for Boeing and his father worked for a phone company.


title: Jim Watkins (businessman)

text: Watkins joined the United States Army in 1982 when he was 18 years old and served until 1998 or 1999. Over his time in the Army, he worked as a helicopter mechanic and recruiter; he reached the rank of sergeant first class in 1994. The Army sent him to a technology school in Virginia in 1987, where he learned about computers and the early Internet.


title: Jim Watkins (businessman)

text: In 1998, while still enlisted, Watkins created a website for Japanese pornography called "Asian Bikini Bar". By hosting it in the United States, he was able to circumvent the strict pornography censorship in Japan. He later renamed the venture "N.T. Technology", which according to Watkins was a meaningless acronym meant to make pornography purchases less conspicuous on credit card statements. N.T. Technology, which is based in Reno, Nevada, initially sold advertising, and later also sold web hosting services to other Japanese adult entertainment websites that couldn't be hosted in Japan. In 1998 or 1999, during the dot-com boom, Watkins left the army to focus on N.T. Technology. In October 2020, "Mother Jones" reported that N.T. Technology has hosted domains with names suggesting connections to child pornography, and that regardless of whether child pornography is hosted on the domains, Watkins is "profiting from words that appeal to the real thing". Watkins dismissed the claim as "an attempt to smear [his] name and print something awful".


title: Jim Watkins (businessman)

text: Watkins has been involved in many business ventures. He operated an organic food restaurant in Manila, Philippines, which is now closed. In 2005, Watkins opened a Manila-based software business called Race Queen, which has subsequently been listed as the employer on Philippine work visas for several employees of Watkins'. Watkins also runs the Manila-based business Loki Technology. He has also been involved with a book narration company called books.audio; he narrated some of the books himself under the alias "A.J.". Watkins is also listed as the chairman of the board of a company called Emerald , which sells piglets.


title: Jim Watkins (businessman)

text: In 2016, around the time he purchased 8chan, Watkins created a news website called "The Goldwater" (named after former presidential candidate Barry Goldwater). The site's content has been described by "The Washington Post" as "notably conspiratorial and amateurish". The videos featured on "The Goldwater" were hosted by American associates of Watkins and by several "attractive Filipina women" who delivered pro-Donald Trump news in heavily accented English. Watkins himself appeared in some of the videos under the alias Jim Cherney. Watkins intended the site to be "a public service to provide news to the 8chan community." However, it became unpopular with many 8chan users, which Watkins attributed to the fact that "Goldwater" is a Jewish-sounding name. One video addressed the Pizzagate conspiracy theory, with Watkins commenting that he believed that the child sex ring existed, though not that it was connected with a pizzeria. The highest point for "The Goldwater" came when it was accredited to cover Trump's June 2018 summit with Kim Jong-un in Singapore.


title: Jim Watkins (businessman)

text: Watkins claimed in a September 2022 stream that he purchased doxxing forum Kiwi Farms after it had been removed from several web hosting services, and that he was looking to bring it and 8kun back to the clearnet. The announcement received mixed reactions from Kiwi Farm's userbase, and site owner Joshua Moon denied it in a Telegram post.


title: Jim Watkins (businessman)

text: 2channel is a textboard website that is extremely popular in Japan, particularly among the very right-wing netto-uyoku. It was created in 1999 by Hiroyuki Nishimura, and is the predecessor to all other "chan" sites including 4chan and 8chan. Nishimura was believed to be making $1million a year from advertising and premium memberships to 2channel in 2008. He hosted the site on N.T. Technology's servers. After a 2013 data breach exposed user credit card data, Watkins seized the 2channel domain in 2014, and took full control of the website and assumed the role of site administrator. He has continued to run the website since, renaming it to 5channel in October 2017 to avoid potential trademark litigation from Nishimura, who owns the "2channel" trademark.


title: Jim Watkins (businessman)

text: Watkins has claimed he seized the 2channel domain because the loss of revenue from the data breach made Nishimura unable to pay hosting costs. Nishimura has claimed that he paid Watkins in full, and that Watkins' seizure of the domain constitutes domain hijacking.


title: Jim Watkins (businessman)

text: 8chan, later renamed 8kun, is an imageboard website known for hosting extreme alt-right and racist content, for being a forum for child pornography, for its role in the Gamergate controversy, and for its links to multiple mass shootings. The site was founded in October 2013 by Fredrick Brennan. After 4chan's founder, Christopher "moot" Poole, banned discussion related to Gamergate in September 2014, Brennan began advertising 8chan as a "free speech friendly 4chan alternative". The site took off—Brennan said in an interview with "Ars Technica" that the site experienced over 4,000 posts an hour that month, a major increase from around 100 posts per hour prior to the 4chan rule change. Brennan found it increasingly difficult to keep up with the server costs of the growing site, and the site experienced frequent downtime as multiple internet service providers denied service due to the site's objectionable content.