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Topic Review
List of Meteor Air Bursts
Many explosions recorded in Earth's atmosphere are likely to be caused by the air bursts that result from meteors exploding as they hit the thicker part of the atmosphere. These types of meteors are also known as fireballs or bolides with the brightest known as superbolides. Before entering Earth's atmosphere, these larger meteors were originally asteroids and comets of a few to several tens of metres in diameter, contrasting with the much smaller and much more common "shooting stars". The most powerful recorded air burst is the 1908 Tunguska event. Extremely bright fireballs traveling across the sky are often witnessed from a distance, such as the 1947 Sikhote-Alin meteor and the 2013 Chelyabinsk meteor, both in Russia. If the bolide is large enough, fragments may survive such as the Chelyabinsk meteorite. Modern developments in infrasound detection by the Comprehensive Nuclear-Test-Ban Treaty Organization and infrared Defense Support Program satellite technology have increased the likelihood of detecting airbursts.
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  • 11 Nov 2022
Topic Review
Statistical Correlations of Criminal Behaviour
The statistical correlations of criminal behavior explore the associations of specific non-criminal factors with specific crimes. The field of criminology studies the dynamics of crime. Most of these studies use correlational data; that is, they attempt to identify various factors are associated with specific categories of criminal behavior. Such correlational studies led to hypotheses about the causes of these crimes. The Handbook of Crime Correlates (2009) is a systematic review of 5200 empirical studies on crime that have been published worldwide. A crime consistency score represents the strength of relationships. The scoring depends on how consistently a statistically significant relationship was identified across multiple studies. The authors claim that the review summarizes most of what is currently known about the variables associated with criminality. Writing in 2019, criminologist Greg Ridgeway argued that criminology was still trying to conclusively determine what causes crime.
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  • 29 Nov 2022
Topic Review
Continuous Casting Practices for Steel
Continuous casting practices for steelmaking have been constantly evolving ever since the early 1930s, when Junghans was first researching ways to pour liquid steel into an open-bottomed, water-cooled mold, to withdraw the partially solidified steel out of it, continuously, in the form of a round or square billet or slab. He envisioned that once these continuously cast shapes had become fully frozen, their solidified ends could be cut off for further processing. In this way, they could be transformed into “rebar” to reinforce concrete, or into bars from which nails, bolts, tire cord wire, etc., could be fashioned, etc. However, long before that, Sir Henry Bessemer had proposed a far more elegant approach, involving two, contra-rotating rolls, into which liquid steel is poured, to produce a thin solidified sheet of steel directly, within a few milliseconds. This is referred to as a Near Net Shape Casting Process. After 150 years of trying, CASTRIP, a subsidiary of NUCOR, BHP, and IHI, made this process a commercial success, where many previous attempts had failed. However, there is an even better NNSC process, referred to as HSBC, or "Horizontal Single Belt Casting", that has also been commercially successful. The HSBC process is capable of casting many different grades of steel, unlike the Bessemer CASTRIP process, by casting ~10 - 15mm thick strips, that can then be rolled down to a final sheet ~1.5 - 0.5mm. thickness, in a one-step continuous process.  
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  • 06 Jun 2022
Topic Review
Georg Cantor's First Set Theory Article
Georg Cantor published his first set theory article in 1874, and it contains the first theorems of transfinite set theory, which studies infinite sets and their properties. One of these theorems is "Cantor's revolutionary discovery" that the set of all real numbers is uncountably, rather than countably, infinite. This theorem is proved using Cantor's first uncountability proof, which differs from the more familiar proof using his diagonal argument. The title of the article, "On a Property of the Collection of All Real Algebraic Numbers" ("Ueber eine Eigenschaft des Inbegriffes aller reellen algebraischen Zahlen"), refers to its first theorem: the set of real algebraic numbers is countable. Cantor's article also contains a proof of the existence of transcendental numbers. As early as 1930, mathematicians have disagreed on whether this proof is constructive or non-constructive. Books as recent as 2014 and 2015 indicate that this disagreement has not been resolved. Since Cantor's proof either constructs transcendental numbers or does not, an analysis of his article can determine whether his proof is constructive or non-constructive. Cantor's correspondence with Richard Dedekind shows the development of his ideas and reveals that he had a choice between two proofs, one that uses the uncountability of the real numbers and one that does not. Historians of mathematics have examined Cantor's article and the circumstances in which it was written. For example, they have discovered that Cantor was advised to leave out his uncountability theorem in the article he submitted; he added it during proofreading. They have traced this and other facts about the article to the influence of Karl Weierstrass and Leopold Kronecker. Historians have also studied Dedekind's contributions to the article, including his contributions to the theorem on the countability of the real algebraic numbers. In addition, they have looked at the article's legacy, which includes the impact that the uncountability theorem and the concept of countability have had on mathematics.
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  • 02 Nov 2022
Topic Review
Sustainability and Sharing Economy
The sharing economy is usually related to sustainability, and it is framed as: (a) an economic opportunity, (b) a more sustainable form of consumption and (c) a pathway to an equitable and sustainable economy. 
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  • 30 Oct 2024
Topic Review
Terrestrial Links Rain Attenuation Models
 Rain is a natural process that attenuates the propagating signal at microwave and millimeter-wave frequencies. Therefore, it is necessary to mitigate rain attenuation to ensure the quality of microwave and millimeter-wave links. To this end, dynamic attenuation mitigation methods are implemented alongside attenuation prediction models that can predict the projected attenuation of the links. Studies on rain attenuation are used in geographically distributed locations to analyze and develop a rain attenuation model applicable over a wide frequency range, particularly radio frequencies over approximately 30 GHz for 5G and beyond network applications.
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  • 02 Jun 2021
Topic Review
Soil Washing
Soil contamination with heavy metals and organic pollutants poses an environmental problem due to their persistence, bioaccumulation and toxicity. Soil washing is one of the most common remediation technologies for permanent removal of undesirable pollutants. The effectiveness of soil washing is affected by many factors such as soil geochemistry, pollutant characteristics, type and chemistry of washing agents, and processing conditions. A variety of washing agents have been tested in soil washing with their different effect on pollutant removal and on the overall quality of treated soil. Development of soil washing is based on searching for an inexpensive, readily-available and environmentally-friendly agents to remediate polluted soils. Despite the unquestionable effectiveness of soil washing, spent washing solutions are generated that need further treatment. This entry presents the principles and application of soil washing technology, as well as the examples of washing agents and methods for liquid waste treatment.  Soil washing is an ex-situ technology, including physical and/or chemical processes that aim to effectively remove pollutants from soil.
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  • 08 Sep 2020
Topic Review
Republic
A republic (Latin: res publica, meaning "public affair") is a form of government in which the country is considered a "public matter", not the private concern or property of the rulers. The primary positions of power within a republic are attained, through democracy, oligarchy, or a mix thereof, rather than being unalterably occupied. It has become the opposing form of government to a monarchy and has therefore no monarch as head of state. (As of 2017), 159 of the world's 206 sovereign states use the word "republic" as part of their official names – not all of these are republics in the sense of having elected governments, nor is the word "republic" used in the names of all nations with elected governments. The word republic comes from the Latin term res publica, which literally means "public thing", "public matter", or "public affair" and was used to refer to the state as a whole. The term developed its modern meaning in reference to the constitution of the ancient Roman Republic, lasting from the overthrow of the kings in 509 BC to the establishment of the Empire in 27 BC. This constitution was characterized by a Senate composed of wealthy aristocrats and wielding significant influence; several popular assemblies of all free citizens, possessing the power to elect magistrates and pass laws; and a series of magistracies with varying types of civil and political authority. Most often a republic is a single sovereign state, but there are also sub-sovereign state entities that are referred to as republics, or that have governments that are described as "republican" in nature. For instance, Article IV of the United States Constitution "guarantee[s] to every State in this Union a Republican form of Government". Another example is the Soviet Union which described itself as being a group of "Soviet Socialist Republics", in reference to the 15 individually federal, multinational, top-level subdivisions or republics. In the context of American constitutional law, the definition of republic refers specifically to a form of government in which elected individuals represent the citizen body and exercise power according to the rule of law under a constitution, including separation of powers with an elected head of state, referred to as a constitutional republic or representative democracy.
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  • 16 Nov 2022
Topic Review
Hybrid Plant
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in blending inheritance), but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are. Species are reproductively isolated by strong barriers to hybridisation, which include genetic and morphological differences, differing times of fertility, mating behaviors and cues, and physiological rejection of sperm cells or the developing embryo. Some act before fertilization and others after it. Similar barriers exist in plants, with differences in flowering times, pollen vectors, inhibition of pollen tube growth, somatoplastic sterility, cytoplasmic-genic male sterility and the structure of the chromosomes. A few animal species and many plant species, however, are the result of hybrid speciation, including important crop plants such as wheat, where the number of chromosomes has been doubled. Human impact on the environment has resulted in an increase in the interbreeding between regional species, and the proliferation of introduced species worldwide has also resulted in an increase in hybridisation. This genetic mixing may threaten many species with extinction, while genetic erosion from monoculture in crop plants may be damaging the gene pools of many species for future breeding. A form of often intentional human-mediated hybridisation is the crossing of wild and domesticated species. This is common in both traditional horticulture and modern agriculture; many commercially useful fruits, flowers, garden herbs, and trees have been produced by hybridisation. One such flower, Oenothera lamarckiana, was central to early genetics research into mutationism and polyploidy. It is also more occasionally done in the livestock and pet trades; some well-known wild × domestic hybrids are beefalo and wolfdogs. Human selective breeding of domesticated animals and plants has resulted in the development of distinct breeds (usually called cultivars in reference to plants); crossbreeds between them (without any wild stock) are sometimes also imprecisely referred to as "hybrids". Hybrid humans existed in prehistory. For example, Neanderthals and anatomically modern humans are thought to have interbred as recently as 40,000 years ago. Mythological hybrids appear in human culture in forms as diverse as the Minotaur, blends of animals, humans and mythical beasts such as centaurs and sphinxes, and the Nephilim of the Biblical apocrypha described as the wicked sons of fallen angels and attractive women.
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  • 24 Nov 2022
Topic Review
A2 Milk and CMPA
 Cows’ milk generally contains two major types of beta-casein as A1 and A2 types, although there are 13 genetic variants of β-casein: A1, A2, A3, A4, B, C, D, E, F, H1, H2, I and G. Studies have shown that A1 β-casein may be harmful, and A2 β-casein is a safer choice for human health especially in infant nutrition and health. The A2 cow milk is reportedly easier to digest and better absorb than A1 or other types of milk. The structure of A2 cow’s milk protein is more comparable to human breast milk, as well as milk from goats, sheep and buffalo. Cow milk protein allergy (CMPA) is considered a common milk digestive and metabolic disorder or allergic disease with various levels of prevalence from 2.5% in children during the first 3 years of life to 12–30% in infants less than 3 months old, and it can go up to even as high as 20% in some countries. CMPA is an IgE-mediated allergy where the body starts to produce IgE antibodies against certain protein (allergens) such as A1 milk and αs1-casein in bovine milk. Studies have shown that ingestion of β-casein A1 milk can cause ischemic heart disease, type-1 diabetes, arteriosclerosis, sudden infant death syndrome, autism, schizophrenia, etc. The knowledge of bovine A2 milk and caprine αs2-casein has been utilized to rescue CMPA patients and other potential disease problems. 
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  • 05 May 2021
Topic Review
Secularity
Secularity (from Latin saeculum, "worldly" or "of a generation") is the state of being separate from religion, or of not being exclusively allied with or against any particular religion. Historically, the word secular was not related or linked to religion, but was a freestanding term in Latin which would relate to any mundane endeavour. However, the term, saecula saeculorum (saeculōrum being the genitive plural of saeculum) as found in the New Testament in the Vulgate translation (circa 410) of the original Koine Greek phrase εἰς τοὺς αἰῶνας τῶν αἰώνων (eis toùs aionas ton aiṓnōn), e.g. at Galatians 1:5, was used in the early Christian church (and is still used today), in the doxologies, to denote the coming and going of the ages, the grant of eternal life, and the long duration of created things from their beginning to forever and ever. The idea of a dichotomy between religion and the secular originated in the European Enlightenment. Furthermore, since religion and secular are both Western concepts that were formed under the influence of Christian theology, other cultures do not necessarily have words or concepts that resemble or are equivalent to them. In many cultures, "little conceptual or practical distinction is made between 'natural' and 'supernatural' phenomena" and the very notions of religious and nonreligious dissolve into unimportance, nonexistence, or unawareness, especially since people have beliefs in other supernatural or spiritual things irrespective of belief in God or gods. Conceptions of what is and what is not religion vary in contemporary East Asia as well. The shared term for "irreligion" or "no religion" (無宗教, Chinese pron. wú zōngjiào, Japanese pron. mu shūkyō) with which the majority of East Asian populations identify themselves implies non-membership in one of the institutional religions (such as Buddhism and Christianity) but not necessarily non-belief in traditional folk religions collectively represented by Chinese Shendao (shén dào) and Japanese Shinto (both meaning "ways of gods").[lower-alpha 1] In modern Japan, religion has negative connotation since it is associated with foreign belief systems so many identify as "nonreligious" (mushukyo), but this does not mean they have a complete rejection or absence of beliefs and rituals relating to supernatural, metaphysical, or spiritual things. In the Meiji era, the Japanese government consciously excluded Shinto from the category of religion in order to enforce State Shinto while asserting their state followed American-mandated requirements for freedom of religion; this has fed into the contemporary Japanese experience of "secularity" as well as the government's regulation of religious beliefs and institutions from the Meiji era into the present day. One can regard eating and bathing as examples of secular activities, because there may not be anything inherently religious about them. Nevertheless, some religious traditions see both eating and bathing as sacraments, therefore making them religious activities within those world views. Saying a prayer derived from religious text or doctrine, worshipping through the context of a religion, performing corporal and spiritual works of mercy, and attending a religious seminary school or monastery are examples of religious (non-secular) activities. The "secular" is experienced in diverse ways ranging from separation of religion and state to being anti-religion or even pro-religion, depending on the culture. For example, the United States has both separation of church and state and pro-religiosity in various forms such as protection of religious freedoms; France has separation of church and state (and French Revolution was strongly anti-religious); the Soviet Union was anti-religion; in India, people feel comfortable identifying as secular while participating in religion; and in Japan, since the concept of "religion" is not indigenous to Japan, people state they have no religion while doing what appears to be religion to Western eyes. A related term, secularism, involves the principle that government institutions and their representatives should remain separate from religious institutions, their beliefs, and their dignitaries. Many businesses and corporations, and some governments operate on secular lines. This stands in contrast to theocracy, government with deity as its highest authority.
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  • 27 Oct 2022
Topic Review
Diffused Religion Beyond Secularization
Diffused religion theory concerns the capacity of a dominant religion in a country to remain solid for centuries.
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  • 01 Nov 2020
Topic Review
Charlotte's Web (Cannabis)
Charlotte's Web is a high-cannabidiol (CBD), low-tetrahydrocannabinol (THC) Cannabis strain marketed as a dietary supplement under federal law of the United States. It is produced by the Stanley brothers in Colorado. It does not induce the psychoactive "high" typically associated with recreational marijuana strains that are high in THC. In September 2014, the Stanleys announced that they would ensure that the product consistently contained less than 0.3% THC. Charlotte's Web is named after Charlotte Figi, born (2006-10-18) October 18, 2006 (age 16), whose story has led to her being described as "the girl who is changing medical marijuana laws across America." Her parents and physicians say she experienced a reduction of her epileptic seizures brought on by Dravet syndrome after her first dose of medical marijuana at five years of age. Her usage of Charlotte's Web was first featured in the 2013 CNN documentary "Weed". Media coverage increased demand for Charlotte's Web and similar products high in CBD, which has been used to treat epilepsy in toddlers and children. It was originally called "Hippie's Disappointment" as it was a strain that had high CBD and could not induce a "high". While anecdotal reports have sparked interest in treatment with cannabinoids, there is not enough evidence to draw conclusions with certainty about their safety or efficacy. Physicians worry that some parents are willing to try treatments before proper research has been conducted, and that they may be disappointed. They are "alarmed by parallels to past miracle-cure manias later proved false..." and "...wary of the heightened placebo effect in treatments involving children, when reports of progress depend on the view of parents."
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  • 02 Nov 2022
Topic Review
N-Acetylcysteine
Exercise frequently alters the metabolic processes of oxidative metabolism in athletes, including exposure to extreme reactive oxygen species impairing exercise performance. Therefore, both researchers and athletes have been consistently investigating the possible strategies to improve metabolic adaptations to exercise-induced oxidative stress. N-acetylcysteine (NAC) has been applied as a therapeutic agent in treating many diseases in humans due to its precursory role in the production of hepatic glutathione, a natural antioxidant.
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  • 03 Feb 2021
Topic Review
Dilophosauridae
Dilophosauridae is a family of medium to large sized theropod dinosaurs. The name Dilophosauridae is derived from Greek, with “di-” meaning “two,” “lophos” meaning “crest,” “sauros” meaning “lizard,” and “-idae” meaning “family”. While the name suggests that all dilophosaurids have two crests, this is not applicable to all dilophosaurids. The Dilophosauridae is anchored by its type genus, Dilophosaurus, and therefore the name comes from the distinctive two crests of the genus.
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  • 24 Oct 2022
Topic Review
Thin-Film Magnetoelastic Materials Based Devices
Thin-film magnetoelastic materials, which couple the magnetization and strain together, have recently attracted ever-increasing attention due to their key roles in magnetoelectric applications. This review starts with the fabrication and characterization techniques in the field of magnetoelastic materials and introduces various kinds of devices utilizing ME effect.
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  • 04 Nov 2020
Topic Review
Deepfake Detection Datasets
Deepfakes are notorious for their unethical and malicious applications to achieve economic, political, and social reputation goals. Although deepfakes were initially associated with entertainment such as movie visual effects, camera filters, and digital avatars, they are defined as “believable generated media by Deep Neural Network” and have evolved into a mainstream tool for facial forgery. With the development of multiple forgery methods, deepfake data are increasing at a annual rate of ~300%. However, the data published online have different forgery qualities. 
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  • 28 Feb 2024
Topic Review
Ottoman Decline Thesis
The Ottoman decline thesis or Ottoman decline paradigm (Turkish: Osmanlı Gerileme Tezi) is an obsolete historical narrative which once played a dominant role in the study of the history of the Ottoman Empire. According to the decline thesis, following a golden age associated with the reign of Sultan Suleiman the Magnificent (r. 1520–1566), the empire gradually entered into a period of all-encompassing stagnation and decline from which it was never able to recover, lasting until the dissolution of the Ottoman Empire in 1923. This thesis was used throughout most of the twentieth century as the basis of both Western and Republican Turkish understanding of Ottoman history. However, by 1978, historians had begun to reexamine the fundamental assumptions of the decline thesis. After the publication of numerous new studies throughout the 1980s, 1990s, and 2000s, and the reexamination of Ottoman history through the use of previously untapped sources and methodologies, academic historians of the Ottoman Empire achieved a consensus that the entire notion of Ottoman decline was a myth – that in fact, the Ottoman Empire did not stagnate or decline at all, but rather continued to be a vigorous and dynamic state long after the death of Suleiman the Magnificent. The decline thesis has been criticized as "teleological", "regressive", "Orientalist", "simplistic", and "one-dimensional", and described as "a concept which has no place in historical analysis". Scholars have thus "learned better than to discuss [it]." Despite this dramatic paradigm shift among professional historians, the decline thesis continues to maintain a strong presence in popular history, as well as academic history written by scholars who are not specialists on the Ottoman Empire. In some cases this is due to the continued reliance by non-specialists on outdated and debunked works, and in others to certain political interests benefiting from the continued perpetuation of the decline narrative.
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  • 22 Nov 2022
Topic Review
Concession (Territory)
In international law, a concession is a territory within a country that is administered by an entity other than the state which holds sovereignty over it.This is usually a colonizing power, or at least mandated by one, as in the case of colonial chartered companies. Usually, it is conceded, that is, allowed or even surrendered by a weaker state to a stronger power. For example, the politically weak and militarily helpless Qing China in the 19th century signed several so-called unequal treaties by which it gave, among other rights, territorial concessions to numerous colonial powers, European as well as Japan , creating a whole host of territorial concessions in China in addition to even more numerous treaty ports where China retained territorial control. However, just as with permanent sales of territory, there are cases when concession has been entered upon voluntarily by a power which could have resisted the demand, believing the arrangement to their mutual interest, or as part of a more complexly balanced deal. Some examples of voluntary concessions are the cemeteries (and monuments) administered by the American Battle Monuments Commission containing United States military dead in Belgium, Cuba, France, Gibraltar, Italy, Luxembourg, Mexico, Morocco, the Netherlands, the Northern Mariana Islands, Panama, Papua New Guinea, the Philippines, the Solomon Islands, Tunisia, and the United Kingdom. In the many cases where the terms of the contract (be it in the form of a treaty between states) provides for similar terms as an ordinary property lease, notably a term limited in time and usually an indemnity sum, the territory can be called more precisely a lease territory or leased territory. The term is not to be confused with 'territorial concession', which applies to any clause in a treaty whereby a power renounces control over any territory, usually in the form of a full and indefinite transfer, often without any indemnity.
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  • 21 Oct 2022
Topic Review
Who Killed Captain Alex?
Who Killed Captain Alex? is a 2010 Ugandan action-comedy film written, produced, and directed by Nabwana IGG, in Wakaliwood, an ultra low-budget studio in Kampala, Uganda. It has gained viral notoriety for being a no-budget action film, produced on a reported budget of under $200. A trailer for the film was uploaded to YouTube in January 2010, and has been viewed over 2.2 million times as of May 2018. The original version of the film was lost due to power outages and "strained conditions", while the surviving version of Who Killed Captain Alex? released online includes an English "Video Joker" commentary that adds in running gags about the characters.
  • 5.2K
  • 02 Oct 2022
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