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🔗 Joy (Programming Language)

🔗 Software 🔗 Software/Computing

The Joy programming language in computer science is a purely functional programming language that was produced by Manfred von Thun of La Trobe University in Melbourne, Australia. Joy is based on composition of functions rather than lambda calculus. It has turned out to have many similarities to Forth, due not to design but to a sort of parallel evolution and convergence. It was also inspired by the function-level programming style of John Backus's FP.

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🔗 Jesuit Reduction

🔗 Brazil 🔗 Portugal 🔗 Catholicism 🔗 Indigenous peoples of the Americas 🔗 Brazil/History of Brazil 🔗 Spain 🔗 South America 🔗 South America/Paraguay

The Jesuit reductions were a type of settlement for indigenous people specifically in the Rio Grande do Sul area of Brazil, Paraguay and neighbouring Argentina in South America, established by the Jesuit Order early in the 17th century and wound up in the 18th century with the banning of the Jesuit order in several European countries. Subsequently, it has been called an experiment in "socialist theocracy" or a rare example of "benign colonialism".

In their newly acquired South American dominions, the Spanish and Portuguese Empires had adopted a strategy of gathering native populations into communities called "Indian reductions" (Spanish: reducciones de indios) and Portuguese: redução (plural reduções). The objectives of the reductions were to impart Christianity and European culture. Secular as well as religious authorities created "reductions".

The Jesuit reductions were Christian missions that extended successfully in an area straddling the borders of present-day Paraguay, Brazil, and Argentina (the triple frontera) amongst the Guaraní peoples. The reductions are often called collectively the Río de la Plata missions. The Jesuits attempted to create a "state within a state" in which the native peoples in the reductions, guided by the Jesuits, would remain autonomous and isolated from Spanish colonists and Spanish rule. A major factor attracting the natives to the reductions was the protection they afforded from enslavement and the forced labour of encomiendas.

Under the leadership of both the Jesuits and native caciques, the reductions achieved a high degree of autonomy within the Spanish colonial empire. With the use of native labour, the reductions became economically successful. When the incursions of Brazilian Bandeirante slave-traders threatened the existence of the reductions, Indian militias were set up, which fought effectively against the Portuguese colonists. However, directly as a result of the Suppression of the Society of Jesus in several European countries, including Spain, in 1767, the Jesuits were expelled from the Guaraní missions (and the Americas) by order of the Spanish king, Charles III. So ended the era of the Paraguayan reductions. The reasons for the expulsion related more to politics in Europe than the activities of the Jesuit missions themselves.

The Jesuit Rio de la Plata reductions reached a maximum population of 141,182 in 1732 in 30 missions in Brazil, Paraguay, and Argentina. The reductions of the Jesuit Missions of Chiquitos in eastern Bolivia reached a maximum population of 25,000 in 1766. Jesuit reductions in the Llanos de Moxos, also in Bolivia, reached a population of about 30,000 in 1720. In Chiquitos, the first reduction was founded in 1691 and in the Llanos de Moxos in 1682.

The Jesuit reductions have been lavishly praised as a "socialist utopia" and a "Christian communistic republic" as well as criticized for their "rigid, severe and meticulous regimentation" of the lives of the Indian people they ruled with a firm hand through Guaraní intermediaries.

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🔗 Dyson Tree

🔗 Science Fiction 🔗 Plants

A Dyson tree is a hypothetical genetically engineered plant (perhaps resembling a tree) capable of growing inside a comet, suggested by the physicist Freeman Dyson. Plants could produce a breathable atmosphere within hollow spaces in the comet (or even within the plants themselves), utilising solar energy for photosynthesis and cometary materials for nutrients, thus providing self-sustaining habitats for humanity in the outer solar system analogous to a greenhouse in space or a shell grown by a mollusc.

A Dyson tree might consist of a few main trunk structures growing out from a comet nucleus, branching into limbs and foliage that intertwine, forming a spherical structure possibly dozens of kilometers across.

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🔗 Miller Columns

🔗 Apple Inc./Macintosh 🔗 Apple Inc.

Miller columns (also known as cascading lists) are a browsing/visualization technique that can be applied to tree structures. The columns allow multiple levels of the hierarchy to be open at once, and provide a visual representation of the current location. It is closely related to techniques used earlier in the Smalltalk browser, but was independently invented by Mark S. Miller in 1980 at Yale University. The technique was then used at Project Xanadu, Datapoint, and NeXT.

While at Datapoint, Miller generalized the technique to browse directed graphs with labeled nodes and arcs. In all cases, the technique is appropriate for structures with high degree (large fanout). For low-degree structures, outline editors or graph viewers are more effective.

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🔗 List of oldest continuously inhabited cities

🔗 Archaeology 🔗 Cities 🔗 Dacia

This is a list of present-day cities by the time period over which they have been continuously inhabited as a city. The age claims listed are generally disputed. Differences in opinion can result from different definitions of "city" as well as "continuous habitation" and historical evidence is often disputed. Caveats (and sources) to the validity of each claim are discussed in the "Notes" column.

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🔗 Non-explosive demolition agents

🔗 Chemical and Bio Engineering

Non-explosive demolition agents are chemicals that are an alternative to explosives and gas pressure blasting products in demolition, mining, and quarrying. To use non-explosive demolition agents in demolition or quarrying, holes are drilled in the base rock as they would be for use with conventional explosives. A slurry mixture of the non-explosive demolition agent and water is poured into the drill holes. Over the next few hours the slurry expands, cracking the rock in a pattern somewhat like the cracking that would occur from conventional explosives.

Non-explosive demolition agents offer many advantages including that they are silent and do not produce vibration the way a conventional explosive would. In some applications conventional explosives are more economical than non-explosive demolition agents. In many countries these are available without restriction, unlike explosives which are highly regulated.

The active ingredient is typically calcium oxide, "burnt lime," and is typically mixed with Portland cement and modifiers.

These agents are much safer than explosives, but they have to be used as directed to avoid steam explosions during the first few hours after being placed.

Many patents describe non-explosive demolition agents containing CaO, SiO2 and/or cement.

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🔗 Fazlur Khan: The engineer who made it possible to live in the sky

🔗 Biography 🔗 Bangladesh 🔗 Architecture 🔗 Skyscrapers 🔗 Civil engineering 🔗 Chicago 🔗 Illinois

Fazlur Rahman Khan (Bengali: ফজলুর রহমান খান, Fozlur Rôhman Khan) (3 April 1929 – 27 March 1982) was a Bangladeshi-American structural engineer and architect, who initiated important structural systems for skyscrapers. Considered the "father of tubular designs" for high-rises, Khan was also a pioneer in computer-aided design (CAD). He was the structural engineer of the Sears Tower working with Architect Bruce Graham, since renamed Willis Tower, the tallest building in the world from 1973 until 1998, and the 100-story John Hancock Center.

Khan, more than any other individual, ushered in a renaissance in skyscraper construction during the second half of the 20th century. He has been called the "Einstein of structural engineering" and the "Greatest Structural Engineer of the 20th Century" for his innovative use of structural systems that remain fundamental to modern skyscraper design and construction. In his honor, the Council on Tall Buildings and Urban Habitat established the Fazlur Khan Lifetime Achievement Medal, as one of their CTBUH Skyscraper Awards.

Although best known for skyscrapers, Khan was also an active designer of other kinds of structures, including the Hajj airport terminal, the McMath–Pierce solar telescope, and several stadium structures.

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🔗 Einstein Refrigerator

🔗 Physics

The Einstein–Szilard or Einstein refrigerator is an absorption refrigerator which has no moving parts, operates at constant pressure, and requires only a heat source to operate. It was jointly invented in 1926 by Albert Einstein and his former student Leó Szilárd, who patented it in the U.S. on November 11, 1930 (U.S. Patent 1,781,541). The three working fluids in this design are water, ammonia and butane. The Einstein refrigerator is a development of the original three-fluid patent by the Swedish inventors Baltzar von Platen and Carl Munters.

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