Design and development.

The D.III was based on the same pattern as the earlier Mercedes D.II, suitably scaled up for higher power settings. Like most inlines of the era, it used a large aluminum crankcase as the main structural component, with separate cylinders made from steel bolted onto it. The technology for screwing a threaded cylinder of steel into an aluminum crankcase did not exist at that time. Jackets for cooling water covered the top 2/3 of the cylinder, feeding a radiator via connections at the back of the engine. The only obvious design change from the earlier D.II was to use separate cooling jackets for each cylinder, whereas the D.II used one jacket each for a trio of adjacent pairs of cylinders.  The D.III featured a rather prominent overhead cam operating the single intake and exhaust valves, powered by a shaft running up from the crankshaft at the rear of the engine. Ignition was provided by two sets of spark plugs, one located on either side of the cylinders, each powered by a separate magneto for redundancy. The ignition cables were protected in tubes running down either side of the cylinders. Fuel was fed into the cylinders via pipes on the port side of the engine, supplied from a twin-barrel carburetor located just above the crankcase. Both the fuel and oil reservoirs were pressurized by an air compressor run off the crank.  Daimler also used the pistons of the D.III to produce the reduction geared, eight-cylinder 220 hp Mercedes D.IV during this period, but it did not see widespread use. The lengthened crankshaft of the D.IV proved prone to breaking.

Production variants.

The original D.III was introduced in 1914. While it saw widespread use in early examples of the C-series of two-seat general-purpose biplanes, the D.III was too large for contemporary fighter designs and did not see use in that role. At the time, fighters were generally powered by lighter rotary engines of power output levels from 80 to about 110 hp, or by water-cooled inline engines in the 100 to 120 hp range such as the earlier Mercedes D.II. By 1916 new designs had grown in size and performance and the D.III became popular on new designs. By 1917 the D.III was being widely used in fighters, most notably on the famous Albatros D.I. Production of this version was essentially wound down by May 1917, with only a handful continuing to be delivered until October. British HP ratings being slightly different (with 746 watts = 1 hp) to the German PS or "Pferdestärke" standard of roughly 735 watts per PS horsepower, it is probable that this engine would have had a slightly higher rating under British HP numbers. Fuel consumption was 11.75 gallons per hour. Its compression ratio was 4.5:1.  Development of the basic design led to the slightly modified 170 hp D.IIIa, which took over on the production lines in June 1917. The main change was to change the piston profile to have a flat head instead of the former concave one, thereby slightly increasing maximum compression to 4.64:1. Other changes were mainly in design details, notably a redesigned crankcase and new carburetor. Many of the accessories were also redesigned or moved around on the engine. This model was produced only briefly, for use on the Albatros D.III but there are indications that possibly some early Albatros (Alb.) made Fokker D.VII's were also equipped but probably had the engines upgraded or replaced as quickly as possible. This engine has been referred to in postwar British analysis as generating 180 hp.  A more "radical" upgrade was the 180/200 hp D.IIIaü, introduced in late 1917, the D.IIIaü was a standardized refinement of the D.III and D.IIIa design and the ü designation was never official. This engine changed the pistons again, this time to a domed profile that further increased the maximum compression – the ü was for "über", meaning "overcompressed". Additionally, a new altitude-compensating carburetor was added, which improved performance at higher altitudes. To support operations at these altitudes, water from the radiator was used to heat the air intake and prevent icing in the carburetor. The aü model, which included upgraded D.III and D.IIIa engine blocks, was the most prolific German fighter engine of 1918 and designed into most fighter designs from late 1917 on. This included most of the entries in the First Fighter Competition at Adlershof in January 1918, notably the famed Fokker D.VII. In British post war evaluation the D.IIIaü demonstrated 200 hp according to the British standards.  A final version attempting to keep the D.III block competitive was the 200 hp (200-217 hp) D.IIIav (or avü), introduced mid-October 1918. The av used slightly longer pistons made of aluminum (possibly a first for a production engine), increasing the compression yet again, while at the same time allowing them to move faster due to the reduced weight. The maximum allowable RPM increased from 1,400 in the earlier models to 1,600 in the av, accounting for most of the gains in power. It is unclear if any av's saw service use. The increased use of Benzol in German aviation fuel may have helped this final upgrade of power, its higher octane rating being better suited for the higher compression ratio.

External differences between models.

All of the D.III series were generally very similar to other models, with the exception of the piston profile, carburetor details and valvetrain details. It appears that upgrades were available for many of the engines, certainly for the III to IIIa, and IIIa to IIIaü. It would seem unlikely that early III's would ever make it to the IIIaü standard, as they would almost certainly have been worn out in service before then. The valvetrain changes concerned the layout of the rocker arms that operated the valves. Early models had square rocker boxes positioned directly over the cylinders with the rocker arms exiting through vertical slots, one cut into each of the opposing sides of the boxes, as shown at left. The earlier "side-slot" rocker arm design had also been used for the Mercedes D.I and D.II engines' valvetrains. In later versions of the D.III engines, the boxes were relocated rearward on the tubular camshaft housing, and the now easily sealable cylindrical rocker arm shafts protruded forwards through the front surfaces of the boxes, operating the now fully exposed rocker arms with the exposed shaft ends, as shown at right. The newer arrangement was stated as being interchangeable as a set with the complete camshaft, rocker boxes, rocker arms and valve springs, with the D.III's earlier "side-slot" cam drive system design - the later system seems to have influenced both Packard's and Hall-Scott's engine designers to adopt a nearly identical "slotless" valvetrain design feature for the Liberty L-12 Allied V-12 aviation engine.  Confusingly, the "ü" was not an official part of the name. This leads to a number of problems in various references, which often confuse the IIIa with the IIIaü, listing the former as a 180 hp engine. There are two D.IV engines — from the "IdFlieg" aircraft powerplant class designations based on power output — one the straight-eight based on the 140mm bore D.III pistons; and the later, six-cylinder Mercedes D.IVa with 160mm bore cylinders, which was essentially unrelated.  The D.III line of engines would find themselves eclipsed in performance by the BMW IIIa of 185 and then 200 hp (British rated it at 230HP) in 1918, however, the small number of BMW's produced ensured that the Mercedes D.III series would be the primary German fighter engine up to the last month or two of the war and it would still be seen in very large numbers even at the end. At the end of the war the D.IIIaü would still be the numerically predominant German fighter engine. As a result, the Fokker D.VII's (those not equipped with BMW IIIa's) and the Pfalz D.XII's would be engine-limited in performance (as opposed to "airframe-limited") and yet would still be formidable adversaries to their Allied counterparts. The D.IIIaü was considered the optimum engine for the Roland D.VI, Pfalz D.IIIa, and Albatros D.Va fighters, whose airframes were of an earlier, "all-wood" generation in design.

The Mercedes D.III, or F1466 as it was known internally, was a six-cylinder, SOHC valvetrain liquid-cooled inline aircraft engine built by Daimler and used on a wide variety of German aircraft during World War I. The initial versions were introduced in 1914 at 160 hp, but a series of changes improved this to 170 hp in 1917, and 180 by mid-1918. These later models were used on almost all late-war German fighters, and its only real competition, the BMW III, was available only in very limited numbers. Compared to the Allied engines it faced, the D.III was generally outdated.

Mercedes D.III nebo také F1466 (interní označení) byl šestiválcový, kapalinou chlazený řadový letecký motor postavený firmou Daimler Motoren Gesellschaft a používaný v širokém spektru německých letadel během první světové války. První verze s výkonem 160 koňských sil vznikly v roce 1914, ale série vylepšení zvýšily výkon nejprve na 170 koňských sil v roce 1917, a poté na 180 v polovině roku 1918. Tyto pozdější modifikace byly montovány do mnoha druhů stíhacích letadel. Byly jediným skutečným "soupeřem" motorů BMW IIIa, kterých byl ovšem nedostatek. Ve srovnání s tehdejšími motory používanými ve spojeneckých letadlech, byly však D.III celkem zastaralé.


Properties.

The numbers 1 and −1 are the only integers coprime to every integer, and they are the only integers that are coprime with 0.  A number of conditions are equivalent to and being coprime:  As a consequence of the third point, if "a" and "b" are coprime and "br" ≡ "bs" (mod "a"), then "r" ≡ "s" (mod "a"). That is, we may "divide by "b"" when working modulo "a". Furthermore, if "b" and "b" are both coprime with "a", then so is their product "b""b" (i.e., modulo "a" it is a product of invertible elements, and therefore invertible); this also follows from the first point by Euclid's lemma, which states that if a prime number "p" divides a product "bc", then "p" divides at least one of the factors "b", "c".  As a consequence of the first point, if "a" and "b" are coprime, then so are any powers "a" and "b".  If "a" and "b" are coprime and "a" divides the product "bc", then "a" divides "c". This can be viewed as a generalization of Euclid's lemma.  The two integers "a" and "b" are coprime if and only if the point with coordinates ("a", "b") in a Cartesian coordinate system is "visible" from the origin (0,0), in the sense that there is no point with integer coordinates on the line segment between the origin and ("a", "b"). (See figure 1.)  In a sense that can be made precise, the probability that two randomly chosen integers are coprime is 6/π (see pi), which is about 61%. See below.  Two natural numbers "a" and "b" are coprime if and only if the numbers 2 − 1 and 2 − 1 are coprime. As a generalization of this, following easily from the Euclidean algorithm in base "n" > 1:

Coprimality in sets.

A set of integers "S" = {"a", "a",... "a"} can also be called "coprime" or "setwise coprime" if the greatest common divisor of all the elements of the set is 1. For example, the integers 6, 10, 15 are coprime because 1 is the only positive integer that divides all of them.  If every pair in a set of integers is coprime, then the set is said to be "pairwise coprime" (or "pairwise relatively prime", "mutually coprime" or "mutually relatively prime"). Pairwise coprimality is a stronger condition than setwise coprimality; every pairwise coprime finite set is also setwise coprime, but the reverse is not true. For example, the integers 4, 5, 6 are (setwise) coprime (because the only positive integer dividing "all" of them is 1), but they are not "pairwise" coprime (because gcd(4, 6) = 2).  The concept of pairwise coprimality is important as a hypothesis in many results in number theory, such as the Chinese remainder theorem.  It is possible for an infinite set of integers to be pairwise coprime. Notable examples include the set of all prime numbers, the set of elements in Sylvester's sequence, and the set of all Fermat numbers.

Coprimality in ring ideals.

Two ideals "A" and "B" in the commutative ring "R" are called coprime (or comaximal) if "A" + "B" = "R". This generalizes Bézout's identity: with this definition, two principal ideals ("a") and ("b") in the ring of integers Z are coprime if and only if "a" and "b" are coprime. If the ideals "A" and "B" of "R" are coprime, then "AB" = "A"∩"B"; furthermore, if "C" is a third ideal such that "A" contains "BC", then "A" contains "C". The Chinese remainder theorem can be generalized to any commutative ring, using coprime ideals.

Probability of coprimality.

Given two randomly chosen integers "a" and "b", it is reasonable to ask how likely it is that "a" and "b" are coprime. In this determination, it is convenient to use the characterization that "a" and "b" are coprime if and only if no prime number divides both of them (see Fundamental theorem of arithmetic).  Informally, the probability that any number is divisible by a prime (or in fact any integer) formula_3 is formula_4; for example, every 7th integer is divisible by 7. Hence the probability that two numbers are both divisible by "p" is formula_5, and the probability that at least one of them is not is formula_6. Any finite collection of divisibility events associated to distinct primes is mutually independent. For example, in the case of two events, a number is divisible by primes "p" and "q" if and only if it is divisible by "pq"; the latter event has probability 1/"pq". If one makes the heuristic assumption that such reasoning can be extended to infinitely many divisibility events, one is led to guess that the probability that two numbers are coprime is given by a product over all primes,  Here "ζ" refers to the Riemann zeta function, the identity relating the product over primes to "ζ"(2) is an example of an Euler product, and the evaluation of "ζ"(2) as "π"/6 is the Basel problem, solved by Leonhard Euler in 1735.  There is no way to choose a positive integer at random so that each positive integer occurs with equal probability, but statements about "randomly chosen integers" such as the ones above can be formalized by using the notion of "natural density". For each positive integer "N", let "P" be the probability that two randomly chosen numbers in formula_8 are coprime. Although "P" will never equal formula_9 exactly, with work one can show that in the limit as formula_10, the probability formula_11 approaches formula_9.  More generally, the probability of "k" randomly chosen integers being coprime is formula_13.

Generating all coprime pairs.

All pairs of positive coprime numbers formula_14 (with formula_15) can be arranged in two disjoint complete ternary trees, one tree starting from formula_16 (for even-odd and odd-even pairs), and the other tree starting from formula_17 (for odd-odd pairs). The children of each vertex formula_18 are generated as follows:  This scheme is exhaustive and non-redundant with no invalid members.

In number theory, two integers and are said to be relatively prime, mutually prime, or coprime (also written co-prime) if the only positive integer (factor) that divides both of them is 1. Consequently, any prime number that divides one does not divide the other. This is equivalent to their greatest common divisor (gcd) being 1.

Nesoudělná čísla jsou v matematice taková celá čísla, která mají pouze jednoho kladného společného dělitele – číslo 1. Ke zjištění nesoudělnosti lze využít například Euklidova algoritmu nebo faktorizaci.


Taxonomy.

The Atlantic bluefin tuna was one of the many fish species originally described by Linnaeus in the landmark 1758 10th edition of his "Systema Naturae", where it was given the binomial name of "Scomber thynnus".  It is most closely related to the Pacific bluefin tuna ("T. orientalis") and the southern bluefin tuna ("T. maccoyii"), and more distantly to the other large tunas of the genus "Thunnus" – the bigeye tuna ("T. obesus") and the yellowfin tuna ("T. albacares"). For many years, the Pacific and Atlantic bluefin tuna species were considered to be the same, or subspecies, and referred to as the "northern bluefin tuna". This name occasionally gives rise to some confusion, as the longtail tuna ("T. tonggol") can in Australia sometimes be known under the name "northern bluefin tuna". This is also true in New Zealand and Fiji.  Bluefin tuna were often referred to as the common tunny, especially in the UK, Australia, and New Zealand. The name "tuna", a derivative of the Spanish "atún", was widely adopted in California in the early 1900s, and has since become accepted for all tunas, including the bluefin, throughout the English-speaking world. In some languages, the red color of the bluefin's meat is included in its name, as in "atún rojo" (Spanish) and "tonno rosso" (Italian), amongst others.

Description.

The body of the Atlantic bluefin tuna is rhomboidal in profile and robust. The head is conical and the mouth rather large. The head contains a "pineal window" that allows the fish to navigate over its multiple thousands-of-miles range. Their color is dark blue above and gray below, with a gold coruscation covering the body and bright yellow caudal finlets. Bluefin tuna can be distinguished from other family members by the relatively short length of their pectoral fins. Their livers have a unique characteristic in that they are covered with blood vessels (striated). In other tunas with short pectoral fins, such vessels are either not present or present in small numbers along the edges.  Fully mature adult specimens average long and weigh around. The largest recorded specimen taken under International Game Fish Association rules was caught off Nova Scotia, an area renowned for huge Atlantic bluefin, and weighed and was long. The longest contest between man and tuna fish occurred near Liverpool, Nova Scotia in 1934, when six men taking turns fought a tuna for 62 hours. Both the Smithsonian Institution and the U. S. National Marine Fisheries Service has accepted that this species can weigh up to, though further details are lacking. Atlantic bluefin tuna reach maturity relatively quickly. In a survey that included specimens up to in length and in weight, none was believed to be older than 15 years. However, very large specimens may be up to 50 years old.  The bluefin possesses enormous muscular strength, which it channels through a pair of tendons to its lunate-shaped caudal fin for propulsion. In contrast to many other fish, the body stays rigid while the tail flicks back and forth, increasing stroke efficiency. It also has a very efficient circulatory system. It possesses one of the highest blood-hemoglobin concentrations among fish, which allows it to efficiently deliver oxygen to its tissues; this is combined with an exceptionally thin blood-water barrier to ensure rapid oxygen uptake. To keep its core muscles warm, which are used for power and steady swimming, the Atlantic bluefin uses countercurrent exchange to prevent heat from being lost to the surrounding water. Heat in the venous blood is efficiently transferred to the cool, oxygenated arterial blood entering a rete mirabile. While all members of the tuna family are warm-blooded, the ability to thermoregulate is more highly developed in bluefin tuna than in any other fish. This allows them to seek food in the rich but chilly waters of the North Atlantic.

Biology and ecology.

Bluefins dive to depths of. They can reach speeds of. The Atlantic bluefin tuna typically hunts small fish such as sardines, herring, and mackerel, and invertebrates such as squid and crustaceans.  The tetraphyllidean tapeworm "Pelichnibothrium speciosum" parasitizes this species. As the tapeworm's definite host is the blue shark, which does not generally seem to feed on tuna, the Atlantic bluefin tuna likely is a dead-end host for "P. speciosum".

Life history.

Female bluefins are thought to produce up to 30 million eggs. Atlantic bluefin tuna spawn in two widely separated areas. One spawning ground exists in the western Mediterranean, particularly in the area of the Balearic Islands. Their other important spawning ground is the Gulf of Mexico. Pop-up satellite tracking results appear to confirm in large measure the belief held by many scientists and fishermen that although bluefin that were spawned in each area may forage widely across the Atlantic, they return to the same area to spawn.  Atlantic bluefins group together in large concentrations to spawn, and at such times are highly vulnerable to commercial fishing. This is particularly so in the Mediterranean, where the groups of spawning bluefins can be spotted from the air by light aircraft and purse seines directed to set around the schools. The western and eastern populations are thought to mature at different ages. Bluefins born in the east are thought to reach maturity a year or two earlier than those spawned in the west.

Human interaction.

Ancient fishery.

According to Longo, "by the turn of the first millennium CE, a sophisticated bluefin tuna trap fishery [had] emerged...This trap fishery, called tonnara in Italian, madrague in French, almadraba in Spanish, and armação in Portuguese, forms an elaborate maze of nets that capture and corral bluefin tuna during their spawning season. Active for more than a thousand years, the traditional/artisanal bluefin tuna trap fishery has experienced a collapse in the Mediterranean and has struggled where it is still practiced."

Commercial fishery.

After World War II, Japanese fishermen needed more tuna to eat and to export for European and U.S. canning industries. They expanded their fishing range and perfected industrial long-line fishing, a practice that employs thousands of baited hooks on miles-long lines. In the 1970s, Japanese manufacturers developed lightweight, high-strength polymers that were spun into drift net. Though they were banned on the high seas by the early 1990s, in the 1970s, hundreds of miles of them were often deployed in a single night. At-sea freezing technology then allowed them to bring frozen sushi-ready tuna from the farthest oceans to market after as long as a year.  The initial target was yellowfin tuna. Japanese did not value bluefin before the 1960s. By the late 1960s, sportfishing for giant bluefin tuna was burgeoning off Nova Scotia, New England, and Long Island. North Americans, too, had little appetite for bluefins, usually discarding them after taking a picture. Bluefin sportfishing's rise, however, coincided with Japan's export boom. In the 1960s and ’70s, cargo planes were returning to Japan empty. A Japanese entrepreneur realized he could buy New England and Canadian bluefins cheaply, and started filling Japan-bound holds with tuna. Exposure to beef and other fatty meats during the U.S. occupation following World War Two had prepared the Japanese palate for bluefin's fatty belly ("otoro"). The Atlantic bluefin was the biggest and the favorite. The appreciation rebounded across the Pacific when Americans started to eat raw fish in the late 1970s.  Prior to the 1960s, Atlantic bluefin fisheries were relatively small scale, and populations remained stable. Although some local stocks, such as those in the North Sea, were damaged by unrestricted commercial fishing, other populations were not at risk. However, in the 1960s, purse seiners catching fish for the canned tuna market in United States coastal waters removed huge numbers of juvenile and young Western Atlantic bluefins, taking out several entire-year classes. Mediterranean fisheries have historically been poorly regulated and catches under-reported, with French, Spanish, and Italian fishermen competing with North African nations for a diminishing population. The fish's migratory habits complicate the task of regulating the fishery, because they spend time in the national waters of multiple countries, as well as the open ocean outside of any national jurisdiction.

Aquaculture.

Tuna ranching began as early as the 1970s. Canadian fishermen in St Mary's Bay captured young fish and raised them in pens. In captivity, they grow to reach hundreds of kilos, eventually fetching premium prices in Japan. Ranching enables ranchers to exploit the unpredictable supply of wild-caught fish. Ranches across the Mediterranean and off South Australia grow bluefins offshore. Annual revenues are $220 million. Large proportions of juvenile and young Mediterranean fish are taken to be grown on tuna farms. Because the tuna are taken from the wild to the pens before they are old enough to reproduce, ranching is one of the most serious threats to the species. The bluefin's slow growth and late sexual maturity compound its problems. The Atlantic population has declined by nearly 90% since the 1970s.  In Europe and Australia, scientists have used light-manipulation technology and time-release hormone implants to bring about the first large-scale captive spawning of Atlantic and southern bluefins. The technology involves implanting gonadotropin-releasing hormone in the fish to stimulate fertile egg production and may push the fish to reach sexual maturity at younger ages.  However, since bluefins require so much food per unit of weight gained - up to 10 times that of salmon - if bluefins were to be farmed at the same scale as 21st-century salmon farming, many of their prey species might become depleted if farmed bluefin were fed the same diet as their wild counterparts. As of 2010, 30 million tons of small forage fish were removed from the oceans yearly, the majority to feed farmed fish.  Market entry by many North African Mediterranean countries, such as Tunisia and Libya in the 1990s, along with the increasingly widespread practice of tuna farming in the Mediterranean and other areas, such as southern Australia (for southern bluefin tuna), depressed prices. One result is that fishermen must now catch up to twice as many fish to maintain their revenues. The Atlantic bluefin is endangered.

Threats.

Global appetite for fish is the predominant threat to Atlantic bluefin. Overfishing continues despite repeated warnings of the current precipitous decline. Bluefin aquaculture, which arose in response to declining wild stocks, has yet to achieve a sustainability, in part because it predominantly relies on harvesting and ranching juveniles rather than captive breeding.  Despite some concern, assessments from the 2010 Deepwater Horizon oil spill estimated that the population loss would not be significant, ranging from 0.4–4.0% of juveniles, which is within the range of annual variations.

Conservation.

Fisheries management organizations.

In 2007, researchers from the International Commission for the Conservation of Atlantic Tunas (ICCAT) — the regulators of Atlantic bluefin fishing—recommended a global quota of 15,000 tonnes to maintain current stocks or 10,000 tonnes to allow the fisheries recovery. ICCAT then chose a quota of 36,000 tonnes, but surveys indicated that up to 60,000 tonnes were actually being taken (a third of the total remaining stocks) and the limit was reduced to 22,500 tonnes. Their scientists now say that 7500 tonnes are the sustainable limit. In November 2009, ICCAT set the 2010 quota at 13,500 tonnes and said that if stocks were not rebuilt by 2022, it would consider closing some areas.  On 18 March 2010, the United Nations rejected a U.S.-backed effort to impose a total ban on Atlantic bluefin tuna fishing and trading. The Convention on International Trade in Endangered Species (CITES) vote was 68 to 20 with 30 European abstentions. The leading opponent, Japan, claimed that ICCAT was the proper regulatory body.  In 2011, the USA's National Oceanic and Atmospheric Administration (NOAA) decided not to list the Atlantic bluefin tuna as an endangered species. NOAA officials said that the more stringent international fishing rules created in November 2010 would be enough for the Atlantic bluefin tuna to recover. NOAA agreed to reconsider the species' endangered status in 2013. It was made a National Marine Fisheries Service Species of Concern, one of those species about which the U.S. government has some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the U.S. Endangered Species Act.  In November 2012, 48 countries meeting in Morocco for the International Commission for the Conservation of Atlantic Tunas voted to keep strict fishing limits, saying the species' population is still fragile. The quota will rise only slightly, from 12,900 metric tons a year to 13,500. The decision was reviewed in November 2014, resulting in higher allowances listed below.  The latest stock assessment for Atlantic bluefin tuna reflected an improvement in the status for both western and eastern Atlantic/Mediterranean stocks. The Commission adopted new management measures that are within the range of scientific advice, are consistent with the respective rebuilding plans, and allow for continued stock growth. For the western stock, the TAC of 2,000 mt annually for 2015 and 2016 will provide for continued growth in spawning stock biomass and allow the strong 2003 year-class to continue to enhance the productivity of the stock. The TAC for the eastern Atlantic/Mediterranean stock was set at 16,142 t for 2015; 19,296 t for 2016; and 23,155 t for 2017.

Other organizations.

In 2010, Greenpeace International added the northern bluefin tuna to its seafood red list.  In the summer of 2011, the Sea Shepherd Conservation Society led a campaign against supposedly illegal bluefin tuna fishing off the coast of Libya, which was under Muammar Gaddafi's regime at the time. The fishermen retaliated against Sea Shepherd's intervention by throwing various, small metal pieces at the crew. Nobody was injured due to the other side's actions during the conflict.  In November 2011, food critic Eric Asimov of "The New York Times" criticized the top-ranked New York City restaurant Sushi Yasuda for offering bluefin tuna on their menu, arguing that drawing from such a threatened fishery constituted an unjustifiable risk to bluefins, and to the future of culinary traditions that depend on the species.  The bluefin species are listed by the Monterey Bay Aquarium on its Seafood Watch list and pocket guides as fish to avoid due to overfishing.

Cuisine.

Atlantic bluefin tuna is one of the most highly prized fish used in Japanese raw fish dishes. About 80% of the caught Atlantic and Pacific bluefin tunas are consumed in Japan. Bluefin tuna sashimi is a particular delicacy in Japan. For example, an Atlantic bluefin caught off eastern United States sold for US$247,000 at the Tsukiji fish market in Tokyo in 2008. This high price is considerably less than the highest prices paid for Pacific bluefin. Prices were highest in the late 1970s and 1980s.  Japanese began eating tuna sushi in the 1840s, when a large catch came into Edo [old Tokyo] one season. A chef marinated a few pieces in soy sauce and served it as "nigiri sushi". At that time, these fish were nicknamed" shibi" — "four days" — because chefs would bury them for four days to mellow their bloody taste.  By the 1930s, tuna sushi was commonplace in Japan.

The Atlantic bluefin tuna ("Thunnus thynnus") is a species of tuna in the family Scombridae. It is variously known as the northern bluefin tuna (mainly when including Pacific bluefin as a subspecies), giant bluefin tuna [for individuals exceeding ], and formerly as the tunny.

Tuňák obecný ("Thunnus thynnus"), také tuňák modroploutvý, je ryba z čeledi makrelovitých rozšířená v Atlantském oceánu, Středozemním a Černém moři a chovaná také v chovech poblíž Japonska. Dosahuje běžně délky 2–2,5 metrů při váze mezi 225 a 250 kg. Tuňák loví menší ryby, a to často i ve velkých hloubkách.


Early life and education.

Max Bruch was born in 1838 in Cologne to Wilhelmine (), a singer, and August Carl Friedrich Bruch, a lawyer who became vice president of the Cologne police. Max had a sister, Mathilde ("Till"). He received his early musical training under the composer and pianist Ferdinand Hiller, to whom Robert Schumann dedicated his piano concerto in A minor. The Bohemian composer and piano virtuoso Ignaz Moscheles recognized his aptitude.  At the age of nine, Bruch wrote his first composition, a song for his mother's birthday. From then on music was his passion, and his studies were enthusiastically supported by his parents. He wrote many minor early works including motets, psalm settings, piano pieces, violin sonatas, a string quartet, and even orchestral works such as the prelude to a planned opera, "Joan of Arc". Few of these early works have survived, and the whereabouts of most of his surviving compositions are unknown.  The first music theory lesson he had was in 1849 in Bonn; it was given by Professor Heinrich Carl Breidenstein, a friend of his father's. At this time, Bruch was staying at an estate in Bergisch Gladbach, where he wrote much of his music. The farm belonged to a lawyer and notary called Neissen, who lived in it with his unmarried sister. The estate was later bought by the Zanders family, who owned a large paper mill. The young Bruch was taught French and English conversation by his father. In later years, became a friend and patron.

Career.

Bruch had a long career as a teacher, conductor and composer, moving among musical posts in Germany: Mannheim (1862–1864), Koblenz (1865–1867), Sondershausen (1867–1870), Berlin (1870–1872), and Bonn, where he spent 1873–78 working privately. At the height of his career he spent three seasons as conductor of the Liverpool Philharmonic Society (1880–83).  He taught composition at the Berlin Hochschule für Musik from 1890 until his retirement in 1910. Notable students included the German pianist, composer, and writer Clara Mathilda Faisst (1872-1948). ""

Personal life and final years.

Bruch married Clara Tuczek, a singer whom he had met on tour, in Berlin on 3 January 1881. The couple returned to Liverpool and took lodgings in Sefton Park. Their daughter, Margaretha, was born in Liverpool in 1882. Bruch died in his house in Berlin-Friedenau in 1920. He was buried, next to his wife (who had died on 26 August the previous year), at the Old St. Matthäus churchyard at Berlin-Schöneberg. Margaretha later had carved on the gravestone "Music is the language of God".

Works.

Bruch's complex and well-structured works in the German Romantic musical tradition placed him in the camp of Romantic classicism exemplified by Johannes Brahms, rather than the opposing "New Music" of Franz Liszt and Richard Wagner. In his time he was known primarily as a choral composer, and to his chagrin was often overshadowed by his friend Brahms, who was more popular and widely regarded.  Today, as it was during his life, Bruch's Violin Concerto No. 1, in G minor, Op. 26 (1866) is one of the most popular Romantic violin concertos. It uses several techniques from Felix Mendelssohn's Violin Concerto in E minor, including the linking of movements, as well as omitting the Classical opening orchestral exposition and other conservative formal structural devices of earlier concertos. Despite these modifications to the conventional Romantic style, Bruch was often considered a conservative composer.  The two other works of Bruch which are still widely played were also written for solo string instrument with orchestra: the "Scottish Fantasy" for violin and orchestra, which includes an arrangement of the tune "Hey Tuttie Tatie", best known for its use in the song "Scots Wha Hae" by Robert Burns; and the "Kol Nidrei", Op. 47, for cello and orchestra (subtitled "Adagio on Hebrew Melodies for Violoncello and Orchestra"), which starts and ends with the solo cello's setting of the Kol Nidre ("All Vows... ") incantation which begins the Jewish (Ashkenazic) Yom Kippur service. This work may well have inspired Ernest Bloch's "Schelomo" (subtitled "Hebrew Rhapsody") of 1916, an even more passionate and extended one-movement composition, also with a Jewish subject and also for solo cello and orchestra.  The success of "Kol Nidrei" led to the assumption by many that Bruch was of Jewish ancestry, although the composer himself refuted this. Indeed, as long as the National Socialist Party was in power (1933-1945), performance of his music was restricted because he was considered a possible Jew for having written music with an openly Jewish theme, despite repeated denials by his surviving family. As a result, his music was largely forgotten in German-speaking countries. There is no evidence, however, that Bruch was Jewish. As far as can be ascertained, none of his ancestors was a Jew. Bruch himself was given the middle name Christian, and was raised Protestant.  In the realm of chamber music, Bruch is not well known, although his "Eight Pieces for Clarinet, Viola and Piano" are occasionally revived, there being very little other music written for this rare combination of instruments. As with Brahms, who had produced his clarinet compositions with a particular clarinetist in mind, so did Bruch write these trios for his own son Max. These pieces do not stand alone, however, in Bruch's output. Nevertheless, he wrote many pieces in the chamber music tradition, of which his septet is noteworthy. His first major pieces, composed at the start of his career, are two string quartets that are similar in tone and intensity to Schumann's string quartets (Op. 41). The composition of his second piano quintet is intriguing, as he began while conductor of the Liverpool Philharmonic Society. Although written for amateurs, it is a fair composition and was completed only after Bruch was gently persuaded, after leaving Liverpool, to finish the last movement. In 1918, towards the end of his life, Bruch once more considered smaller ensembles with the composition of two string quintets, of which one served as the basis for a string octet, written in 1920 for four violins, two violas, cello and a double bass. This octet is somewhat at odds with the innovative style of the decade. While composers such as Schönberg and Stravinsky were part of the forward-looking modern trend, Bruch and others tried to keep composing within the Romantic tradition, effectively glorifying a form of Late Romanticism and avoiding the revolutionary spirit that was engulfing the then-defeated Germany. All three of these late chamber works exhibit a 'concertante' style in which the first violin part is predominant and contains much of the musical interest. By the time they came to be performed professionally for the first time, in the 1930s, Bruch's reputation had deteriorated and he was known only for the famous Concerto.  Bruch's other works include two concerti for violin and orchestra, No. 2 in D minor (1878) and No. 3 in D minor (1891) (which Bruch himself regarded as at least as fine as the famous first); as well as a lovely and melodic Concerto for Clarinet, Viola and Orchestra, and many more pieces for violin, viola or cello and orchestra. His three symphonies contain distinctive German Romantic melodic writing effectively orchestrated.  To this triple output he added three orchestral suites in later life, of which the third has a remarkable history. The origin can be found in Capri, where Bruch had witnessed a procession in which a tuba played a tune that "could very well be the basis of a funeral march", and would be the basis of this suite, finished in 1909. The American Sutro sisters piano duo, Rose and Ottilie Sutro, however, had asked Bruch for a concerto specifically for them, which he produced by arranging this suite into a double piano concerto, but only to be played within the Americas and not beyond. The Concerto in A-flat minor for Two Pianos and Orchestra, Op. 88a, was finished in 1912 for the Sutros, but was never played in the original version. They performed the work only twice, in two different versions of their own. The score was withdrawn in 1917 and rediscovered only after Ottilie Sutro's death in 1970. The sisters also played a major part in the fate of the manuscript of the Violin Concerto No. 1: Bruch had sent it to them to be sold in the United States, but they kept it and sold it for profit themselves.  Violinists Joseph Joachim and Willy Hess advised Bruch on his writing for that instrument, and Hess premiered some of his works including the "Concert Piece for Violin and Orchestra", Op. 84, which was composed for him.

Max Bruch (6 January 1838 – 2 October 1920) was a German Romantic composer, teacher, and conductor who wrote over 200 works, including three violin concertos, the first of which has become a staple of the violin repertoire.

Max Christian Friedrich Bruch (6. ledna 1838 Kolín nad Rýnem – 20. října 1920 Friedenau) byl německý hudební skladatel a dirigent.


Ecology.

The genus includes a variety of living forms, occurring from rainforest to semi-desert habitats; many are climbing plants. The differences among them came from the communities and ecosystems in which they occur, and the ecological and evolutionary processes that keep them functioning, yet ever changing and adapting. Most are dispersed by birds.  Ornamental species such as "Asparagus plumosus", "Asparagus aethiopicus", "Asparagus setaceus", and "Asparagus virgatus" are finely branched and are misleadingly known as "asparagus fern".  In the Macaronesian Islands, several species (such as "Asparagus umbellatus" and "Asparagus scoparius") grow in moist laurel forest habitat, and preserve the original form of a leafy vine. In the drier Mediterranean climate the asparagus genus evolved in the Tertiary into thorny, drought-adapted species. Root tubers are storage organs developed by Asparagus spp. and are a valuable source of moisture and nutrition for species growing under drought conditions.  Many species, particularly from Africa, were once included in separate genera such as Protasparagus and Myrsiphyllum. However, partly in response to the implications of the discovery of new species, those genera have been reunited under "Asparagus". Species in this genus vary in their appearance, from unarmed herbs to wiry, woody climbers with formidable hooked spines that earn them vernacular names such as "cat thorn" and "wag 'n bietjie" (literally "wait a bit"). Most species have photosynthetic flattened stems, called phylloclades, instead of true leaves. "Asparagus officinalis", "Asparagus schoberioides", and "Asparagus cochinchinensis" are dioecious species, with male and female flowers on separate plants.

Selected species.

, the World Checklist of Selected Plant Families accepts 212 species of "Asparagus", including:

Invasive species.

"A. asparagoides", known as bridal creeper, is a problematic weed in southern Australia.  "A. asparagoides", "A. aethiopicus" (under the name "A. densiflorus") and "A. scandens" are listed on the New Zealand National Pest Plant Accord since they are invasive plants.

Asparagus is a genus of flowering plants in the family Asparagaceae, subfamily Asparagoideae. It comprises up to 300 species. Most are evergreen long-lived perennial plants growing from the understory as lianas, bushes or climbing plants. The best-known species is the edible "Asparagus officinalis", commonly referred to as just "asparagus". Some other members of the genus, such as "Asparagus densiflorus", are grown as ornamental plants.

Chřest ("Asparagus") je rod jednoděložných rostlin z čeledi chřestovité ("Asparagaceae"). V některých starších taxonomických systémech byl řazen do čeledi liliovité v širším pojetí ("Liliaceae" s.l.).


History.

Inter Bratislava was founded in 1940 by the Apollo refinery (later renamed Slovnaft). Following the end of World War II and the re-establishment of Czechoslovakia, the club developed into an important force in Czechoslovak football. While it remains unclear, whether it is Inter Bratislava or FK ŠKP Inter Dúbravka Bratislava, who can claim the successful run of Červená Hviezda Bratislava in the 1950s and early 1960s as its own, club's achievements in the subsequent decades (as TJ Internacionál Slovnaft Bratislava) can be hardly disputed. Between 1962 and 1993 the club spent 29 out of 31 seasons in the Czechoslovak top flight, finishing twice as runner-up in the 1970s and winning the Slovak Cup in the seasons 1983–84, 1987–88, and 1989–90. Over these years, a number of Inter players represented Czechoslovakia at senior level. In 1976, Jozef Barmoš, Ladislav Jurkemik, and Ladislav Petráš were in the squad that won the UEFA Euro 1976. Four years later, Barmoš and Jurkemik were also a part of the side that finished third at the 1980 European Championship. In a decade that followed the dissolution of Czechoslovakia, Inter went on to flourish in the newly established top tier of Slovak football as well as in the Slovak Cup, winning the Slovak double in the 1999–2000 and 2000–2001 seasons.

Inter's fall and re-establishment.

Inter Bratislava won the 1. liga in the 2008–2009 season and was supposed to be promoted to the Slovak top flight. However, financial problems of the club led its owner Ľubomír Chrenko to sell Inter's licence to FK Senica in June 2009. As a result, players of the senior squad of Inter Bratislava joined Senica, whilst youth teams of Inter were preserved by the Inter Bratislava Civic Association, which had been formed from the Inter Fan Club.  The senior side was re-established in the 2010–2011 season, playing in the V. liga, i.e. the sixth tier of Slovak football. Major changes in the structure of the club were accompanied by Inter's move from the Štadión Pasienky, which had been used by the team since 1967, to the considerably smaller Štadión Drieňová ulica. After playing at the Štadión Drieňová ulica for four seasons, the senior team moved to the Štadión ŠKP Inter Dúbravka in the summer of 2014. The grounds have a capacity of 10,200. Since the season 2015/2016 due to unknown issues the Men team returned to stadium Drieňová ulica and the youth teams remained on Stadium ŠKP Inter Dúbravka. In the autumn part of the season 2016/2017 Inter was playing home matches on the stadium in Petržalka on Marie Curie-Skłodowska street (stadium of FC Petržalka akadémia), but in spring 2017 the team moved to the city of Stupava, where the team owners created the training center for Inter. The future plans are to return to Bratislava, Stupava serving as the training center.

Affiliated clubs.

The following clubs are affiliated with FK Inter Bratislava:

Stadium.

Former stadium.

Stadium Pasienky is a multi-use stadium in Bratislava, Slovakia. It was used mostly for football matches and was the home ground of FK Inter Bratislava. The stadium holds 13,295 people.

Current stadium.

Since the 2014/2015 season, the home ground of FK Inter Bratislava has been the Štadión ŠKP Inter Dúbravka. Since the season 2015/2016 due to unknown issues the Men team returned to stadium Drieňová ulica and the youth teams remained on Stadium ŠKP Inter Dúbravka. In the autumn part of the season 2016/2017 Inter was playing home matches on the stadium in Petržalka on Marie Curie-Skłodowska street (stadium of FC Petržalka akadémia), but in spring 2017 the team moved to the city of Stupava, where the team owners created the training center for Inter. The future plans are to return to Bratislava, Stupava serving as the training center.

Honours.

Domestic.

Czechoslovakia  Individual Club

Czechoslovak and Slovak Top Goalscorer.

The Czechoslovak League top scorer from 1944 to 1945 until 1992–93. Since the 1993–94 Slovak League Top scorer.

Europe.

International Football Cup "(Intertoto Cup)"  Mitropa Cup

Players.

Current squad.

"As of 24 March 2019"  "For recent transfers, see List of Slovak football transfers winter 2018–19."

Results.

League and domestic cup history.

"Slovak League only (1993–present)"

Notable players.

Had international caps for their respective countries. Players whose name is listed in bold represented their countries while playing for Inter.

FK Inter Bratislava () is a Slovak football club based in Bratislava, playing its home matches at this moment at the stadium in Stupava. The club will be competing in 2. liga, the second tier in the Slovak football league system, after winning 3. liga Bratislava in the 2016–17 season.

FK Inter Bratislava (celým názvem: Futbalový klub Inter Bratislava) je slovenský fotbalový klub, který sídlí v bratislavské městské části Nové Mesto. Jedná se o bývalého dlouholetého účastníka první československé, posléze slovenské fotbalové ligy. Založen byl v roce 1940 pod názvem ŠK Apollo Bratislava. Od sezóny 2017/18 působí ve druhé fotbalové lize.


Biography.

Born in Vysoké Mýto, Tauberová moved with her family to Vienna at the age of 9. She entered the Vienna Music Academy where she initially studied piano and then singing with Ferdinand Rebay. She later pursued further vocal training in Milan with Fernando Carpi in 1934. She began her career in Vienna, portraying the title role in Fritz Kreisler's operetta "Sissy" for a total of 360 performances.  In 1936 Tauberová made her débuts in Plzeň and then at the National Theatre in Prague, where she continued to sing until 1973. She made her debut with the company as Gilda in "Rigoletto". Among her signature roles at the house were Susanna in "The Marriage of Figaro", Despina in "Così fan tutte", Zerlina in "Don Giovanni", Eurydice in Talich’s interpretation of Christoph Willibald Gluck’s "Orfeo ed Euridice", Marguerite in "Faust", Zerbinetta in "Ariadne auf Naxos", Olympia in "Les contes d'Hoffmann", Rosina in "The Barber of Seville", and Violetta in "La traviata". In the Czech repertoire she was admired for her portrayals of Karolina in "The Two Widows" and the title roles in "The Cunning Little Vixen", "Mirandolina", and "Julietta". She made a number of recordings with the National Theatre on the Supraphon label.  In 1937-1938 Tauberová was a guest at the Opéra de Monte-Carlo and in the late 1930s and 1940s she made appearances at the Grand Théâtre de Genève, the Lausanne Opera, Den Norske Opera, the Royal Opera House in London and the Berlin State Opera. In 1946 she and her husband were committed to the Teatro Municipal in Rio de Janeiro. In 1970 she sang at the Edinburgh Festival with the Prague National Theater. In 1957 she toured Russia with the Czech Philharmonic Orchestra. Throughout her career she was a frequent guest artist at the Vienna State Opera and at the opera houses in Budapest, Bucharest, and Sofia. In 1994 she was honored with a Thalia Award. She died in Prague in 2003.

Maria Tauberová (née Proskeová) (28 April 1911 – 16 January 2003) was a Czech opera singer who had an active international career from the 1930s through the 1970s. A lyric coloratura soprano with an excellent technique, she possessed a warm bright voice that was even in all registers. She was particularly admired for her portrayal of Mozart heroines. In addition to an almost four-decade career at the Prague National Theatre, she sang throughout Europe and in South America, frequently with her husband, conductor Jaroslav Krombholc.

Maria Tauberová (28. dubna 1911 Vysoké Mýto – 16. ledna 2003 Praha) byla česká operní pěvkyně, sopranistka Národního divadla v Praze.


History.

Background.

The origins of both the microprocessor and the microcontroller can be traced back to the invention of the MOSFET (metal-oxide-semiconductor field-effect transistor), also known as the MOS transistor. It was invented by Mohamed M. Atalla and Dawon Kahng at Bell Labs in 1959, and first demonstrated in 1960. The same year, Atalla proposed the concept of the MOS integrated circuit, which was an integrated circuit chip fabricated from MOSFETs. By 1964, MOS chips had reached higher transistor density and lower manufacturing costs than bipolar chips. MOS chips further increased in complexity at a rate predicted by Moore's law, leading to large-scale integration (LSI) with hundreds of transistors on a single MOS chip by the late 1960s. The application of MOS LSI chips to computing was the basis for the first microprocessors, as engineers began recognizing that a complete computer processor could be contained on a single MOS LSI chip.  The first multi-chip microprocessors, the Four-Phase Systems AL1 in 1969 and the Garrett AiResearch MP944 in 1970, were developed with multiple MOS LSI chips. The first single-chip microprocessor was the Intel 4004, released on a single MOS LSI chip in 1971. It was developed by Federico Faggin, using his silicon-gate MOS technology, along with Intel engineers Marcian Hoff and Stan Mazor, and Busicom engineer Masatoshi Shima. It was followed by the 4-bit Intel 4040, the 8-bit Intel 8008, and the 8-bit Intel 8080. All of these processors required several external chips to implement a working system, including memory and peripheral interface chips. As a result, the total system cost was several hundred (1970s US) dollars, making it impossible to economically computerize small appliances. MOS Technology introduced sub-$100 microprocessors, the 6501 and 6502, with the chief aim of addressing this economic obstacle, but these microprocessors still required external support, memory, and peripheral chips which kept the total system cost in the hundreds of dollars.

Development.

One book credits TI engineers Gary Boone and Michael Cochran with the successful creation of the first microcontroller in 1971. The result of their work was the TMS 1000, which became commercially available in 1974. It combined read-only memory, read/write memory, processor and clock on one chip and was targeted at embedded systems.  During the early-to-mid-1970s, Japanese electronics manufacturers began producing microcontrollers for automobiles, including 4-bit MCUs for in-car entertainment, automatic wipers, electronic locks, and dashboard, and 8-bit MCUs for engine control.  Partly in response to the existence of the single-chip TMS 1000, Intel developed a computer system on a chip optimized for control applications, the Intel 8048, with commercial parts first shipping in 1977. It combined RAM and ROM on the same chip with a microprocessor. Among numerous applications, this chip would eventually find its way into over one billion PC keyboards. At that time Intel's President, Luke J. Valenter, stated that the microcontroller was one of the most successful products in the company's history, and he expanded the microcontroller division's budget by over 25%.  Most microcontrollers at this time had concurrent variants. One had EPROM program memory, with a transparent quartz window in the lid of the package to allow it to be erased by exposure to ultraviolet light. These erasable chips were often used for prototyping. The other variant was either a mask programmed ROM or a PROM variant which was only programmable once. For the latter, sometimes the designation OTP was used, standing for "one-time programmable". In an OTP microcontroller, the PROM was usually of identical type as the EPROM, but the chip package had no quartz window; because there was no way to expose the EPROM to ultraviolet light, it could not be erased. Because the erasable versions required ceramic packages with quartz windows, they were significantly more expensive than the OTP versions, which could be made in lower-cost opaque plastic packages. For the erasable variants, quartz was required, instead of less expensive glass, for its transparency to ultraviolet light—to which glass is largely opaque—but the main cost differentiator was the ceramic package itself.  In 1993, the introduction of EEPROM memory allowed microcontrollers (beginning with the Microchip PIC16C84) to be electrically erased quickly without an expensive package as required for EPROM, allowing both rapid prototyping, and in-system programming. (EEPROM technology had been available prior to this time, but the earlier EEPROM was more expensive and less durable, making it unsuitable for low-cost mass-produced microcontrollers.) The same year, Atmel introduced the first microcontroller using Flash memory, a special type of EEPROM. Other companies rapidly followed suit, with both memory types.  Nowadays microcontrollers are cheap and readily available for hobbyists, with large online communities around certain processors.

Volume and cost.

In 2002, about 55% of all CPUs sold in the world were 8-bit microcontrollers and microprocessors.  Over two billion 8-bit microcontrollers were sold in 1997, and according to Semico, over four billion 8-bit microcontrollers were sold in 2006. More recently, Semico has claimed the MCU market grew 36.5% in 2010 and 12% in 2011.  A typical home in a developed country is likely to have only four general-purpose microprocessors but around three dozen microcontrollers. A typical mid-range automobile has about 30 microcontrollers. They can also be found in many electrical devices such as washing machines, microwave ovens, and telephones.  Cost to manufacture can be under $0.10 per unit.  Cost has plummeted over time, with the cheapest 8-bit microcontrollers being available for under in 2018, and some 32-bit microcontrollers around US$1 for similar quantities.  In 2012, following a global crisis—a worst ever annual sales decline and recovery and average sales price year-over-year plunging 17%—the biggest reduction since the 1980s—the average price for a microcontroller was US$0.88 ($0.69 for 4-/8-bit, $0.59 for 16-bit, $1.76 for 32-bit). In 2012, worldwide sales of 8-bit microcontrollers were around $4 billion, while 4-bit microcontrollers also saw significant sales. In 2015, 8-bit microcontrollers could be bought for $0.311 (1,000 units), 16-bit for $0.385 (1,000 units), and 32-bit for $0.378 (1,000 units, but at $0.35 for 5,000).  In 2018, 8-bit microcontrollers can be bought for $0.03, 16-bit for $0.393 (1,000 units, but at $0.563 for 100 or $0.349 for full reel of 2,000), and 32-bit for $0.503 (1,000 units, but at $0.466 for 5,000). A lower-priced 32-bit microcontroller, in units of one, can be had for $0.891.  In 2018, the low-priced microcontrollers above from 2015 are all more expensive (with inflation calculated between 2018 and 2015 prices for those specific units) at: the 8-bit microcontroller can be bought for $0.319 (1,000 units) or 2.6% higher, the 16-bit one for $0.464 (1,000 units) or 21% higher, and the 32-bit one for $0.503 (1,000 units, but at $0.466 for 5,000) or 33% higher.

Smallest computer.

On 21 June 2018, the "world's smallest computer" was announced by the University of Michigan. The device is a "0.04mm3 16nW wireless and batteryless sensor system with integrated Cortex-M0+ processor and optical communication for cellular temperature measurement." It "measures just 0.3 mm to a side—dwarfed by a grain of rice. [...] In addition to the RAM and photovoltaics, the new computing devices have processors and wireless transmitters and receivers. Because they are too small to have conventional radio antennae, they receive and transmit data with visible light. A base station provides light for power and programming, and it receives the data." The device is 1/10th the size of IBM's previously claimed world-record-sized computer from months back in March 2018, which is "smaller than a grain of salt", has a million transistors, costs less than $0.10 to manufacture, and, combined with blockchain technology, is intended for logistics and “crypto-anchors”—”digital fingerprints” applications.

Embedded design.

A microcontroller can be considered a self-contained system with a processor, memory and peripherals and can be used as an embedded system. The majority of microcontrollers in use today are embedded in other machinery, such as automobiles, telephones, appliances, and peripherals for computer systems.  While some embedded systems are very sophisticated, many have minimal requirements for memory and program length, with no operating system, and low software complexity. Typical input and output devices include switches, relays, solenoids, LED's, small or custom liquid-crystal displays, radio frequency devices, and sensors for data such as temperature, humidity, light level etc. Embedded systems usually have no keyboard, screen, disks, printers, or other recognizable I/O devices of a personal computer, and may lack human interaction devices of any kind.

Interrupts.

Microcontrollers must provide real-time (predictable, though not necessarily fast) response to events in the embedded system they are controlling. When certain events occur, an interrupt system can signal the processor to suspend processing the current instruction sequence and to begin an interrupt service routine (ISR, or "interrupt handler") which will perform any processing required based on the source of the interrupt, before returning to the original instruction sequence. Possible interrupt sources are device dependent, and often include events such as an internal timer overflow, completing an analog to digital conversion, a logic level change on an input such as from a button being pressed, and data received on a communication link. Where power consumption is important as in battery devices, interrupts may also wake a microcontroller from a low-power sleep state where the processor is halted until required to do something by a peripheral event.

Programs.

Typically micro-controller programs must fit in the available on-chip memory, since it would be costly to provide a system with external, expandable memory. Compilers and assemblers are used to convert both high-level and assembly language codes into a compact machine code for storage in the micro-controller's memory. Depending on the device, the program memory may be permanent, read-only memory that can only be programmed at the factory, or it may be field-alterable flash or erasable read-only memory.  Manufacturers have often produced special versions of their micro-controllers in order to help the hardware and software development of the target system. Originally these included EPROM versions that have a "window" on the top of the device through which program memory can be erased by ultraviolet light, ready for reprogramming after a programming ("burn") and test cycle. Since 1998, EPROM versions are rare and have been replaced by EEPROM and flash, which are easier to use (can be erased electronically) and cheaper to manufacture.  Other versions may be available where the ROM is accessed as an external device rather than as internal memory, however these are becoming rare due to the widespread availability of cheap microcontroller programmers.  The use of field-programmable devices on a micro controller may allow field update of the firmware or permit late factory revisions to products that have been assembled but not yet shipped. Programmable memory also reduces the lead time required for deployment of a new product.  Where hundreds of thousands of identical devices are required, using parts programmed at the time of manufacture can be economical. These "mask programmed" parts have the program laid down in the same way as the logic of the chip, at the same time.  A customized micro-controller incorporates a block of digital logic that can be personalized for additional processing capability, peripherals and interfaces that are adapted to the requirements of the application. One example is the AT91CAP from Atmel.

Other microcontroller features.

Microcontrollers usually contain from several to dozens of general purpose input/output pins (GPIO). GPIO pins are software configurable to either an input or an output state. When GPIO pins are configured to an input state, they are often used to read sensors or external signals. Configured to the output state, GPIO pins can drive external devices such as LEDs or motors, often indirectly, through external power electronics.  Many embedded systems need to read sensors that produce analog signals. This is the purpose of the analog-to-digital converter (ADC). Since processors are built to interpret and process digital data, i.e. 1s and 0s, they are not able to do anything with the analog signals that may be sent to it by a device. So the analog to digital converter is used to convert the incoming data into a form that the processor can recognize. A less common feature on some microcontrollers is a digital-to-analog converter (DAC) that allows the processor to output analog signals or voltage levels.  In addition to the converters, many embedded microprocessors include a variety of timers as well. One of the most common types of timers is the programmable interval timer (PIT). A PIT may either count down from some value to zero, or up to the capacity of the count register, overflowing to zero. Once it reaches zero, it sends an interrupt to the processor indicating that it has finished counting. This is useful for devices such as thermostats, which periodically test the temperature around them to see if they need to turn the air conditioner on, the heater on, etc.  A dedicated pulse-width modulation (PWM) block makes it possible for the CPU to control power converters, resistive loads, motors, etc., without using lots of CPU resources in tight timer loops.  A universal asynchronous receiver/transmitter (UART) block makes it possible to receive and transmit data over a serial line with very little load on the CPU. Dedicated on-chip hardware also often includes capabilities to communicate with other devices (chips) in digital formats such as Inter-Integrated Circuit (I2C), Serial Peripheral Interface (SPI), Universal Serial Bus (USB), and Ethernet.

Higher integration.

Micro-controllers may not implement an external address or data bus as they integrate RAM and non-volatile memory on the same chip as the CPU. Using fewer pins, the chip can be placed in a much smaller, cheaper package.  Integrating the memory and other peripherals on a single chip and testing them as a unit increases the cost of that chip, but often results in decreased net cost of the embedded system as a whole. Even if the cost of a CPU that has integrated peripherals is slightly more than the cost of a CPU and external peripherals, having fewer chips typically allows a smaller and cheaper circuit board, and reduces the labor required to assemble and test the circuit board, in addition to tending to decrease the defect rate for the finished assembly.  A micro-controller is a single integrated circuit, commonly with the following features:  This integration drastically reduces the number of chips and the amount of wiring and circuit board space that would be needed to produce equivalent systems using separate chips. Furthermore, on low pin count devices in particular, each pin may interface to several internal peripherals, with the pin function selected by software. This allows a part to be used in a wider variety of applications than if pins had dedicated functions.  Micro-controllers have proved to be highly popular in embedded systems since their introduction in the 1970s.  Some microcontrollers use a Harvard architecture: separate memory buses for instructions and data, allowing accesses to take place concurrently. Where a Harvard architecture is used, instruction words for the processor may be a different bit size than the length of internal memory and registers; for example: 12-bit instructions used with 8-bit data registers.  The decision of which peripheral to integrate is often difficult. The microcontroller vendors often trade operating frequencies and system design flexibility against time-to-market requirements from their customers and overall lower system cost. Manufacturers have to balance the need to minimize the chip size against additional functionality.  Microcontroller architectures vary widely. Some designs include general-purpose microprocessor cores, with one or more ROM, RAM, or I/O functions integrated onto the package. Other designs are purpose built for control applications. A micro-controller instruction set usually has many instructions intended for bit manipulation (bit-wise operations) to make control programs more compact. For example, a general purpose processor might require several instructions to test a bit in a register and branch if the bit is set, where a micro-controller could have a single instruction to provide that commonly required function.  Microcontrollers traditionally do not have a math coprocessor, so floating point arithmetic is performed by software. However, some recent designs do include an FPU and DSP optimized features. An example would be Microchip's PIC32 MIPS based line.

Programming environments.

Microcontrollers were originally programmed only in assembly language, but various high-level programming languages, such as C, Python and JavaScript, are now also in common use to target microcontrollers and embedded systems. Compilers for general purpose languages will typically have some restrictions as well as enhancements to better support the unique characteristics of microcontrollers. Some microcontrollers have environments to aid developing certain types of applications. Microcontroller vendors often make tools freely available to make it easier to adopt their hardware.  Microcontrollers with specialty hardware may require their own non-standard dialects of C, such as SDCC for the 8051, which prevent using standard tools (such as code libraries or static analysis tools) even for code unrelated to hardware features. Interpreters may also contain nonstandard features, such as MicroPython, although a fork, CircuitPython, has looked to move hardware dependencies to libraries and have the language adhere to a more CPython standard.  Interpreter firmware is also available for some microcontrollers. For example, BASIC on the early microcontrollers Intel 8052; BASIC and FORTH on the Zilog Z8 as well as some modern devices. Typically these interpreters support interactive programming.  Simulators are available for some microcontrollers. These allow a developer to analyze what the behavior of the microcontroller and their program should be if they were using the actual part. A simulator will show the internal processor state and also that of the outputs, as well as allowing input signals to be generated. While on the one hand most simulators will be limited from being unable to simulate much other hardware in a system, they can exercise conditions that may otherwise be hard to reproduce at will in the physical implementation, and can be the quickest way to debug and analyze problems.  Recent microcontrollers are often integrated with on-chip debug circuitry that when accessed by an in-circuit emulator (ICE) via JTAG, allow debugging of the firmware with a debugger. A real-time ICE may allow viewing and/or manipulating of internal states while running. A tracing ICE can record executed program and MCU states before/after a trigger point.

Types.

, there are several dozen microcontroller architectures and vendors including:  Many others exist, some of which are used in very narrow range of applications or are more like applications processors than microcontrollers. The microcontroller market is extremely fragmented, with numerous vendors, technologies, and markets. Note that many vendors sell or have sold multiple architectures.

Interrupt latency.

In contrast to general-purpose computers, microcontrollers used in embedded systems often seek to optimize interrupt latency over instruction throughput. Issues include both reducing the latency, and making it be more predictable (to support real-time control).  When an electronic device causes an interrupt, during the context switch the intermediate results (registers) have to be saved before the software responsible for handling the interrupt can run. They must also be restored after that interrupt handler is finished. If there are more processor registers, this saving and restoring process may take more time, increasing the latency. (If an ISR does not require the use of some registers, it may simply leave them alone rather than saving and restoring them, so in that case those registers are not involved with the latency.) Ways to reduce such context/restore latency include having relatively few registers in their central processing units (undesirable because it slows down most non-interrupt processing substantially), or at least having the hardware not save them all (this fails if the software then needs to compensate by saving the rest "manually"). Another technique involves spending silicon gates on "shadow registers": One or more duplicate registers used only by the interrupt software, perhaps supporting a dedicated stack.  Other factors affecting interrupt latency include:  Lower end microcontrollers tend to support fewer interrupt latency controls than higher end ones.

Memory technology.

Two different kinds of memory are commonly used with microcontrollers, a non-volatile memory for storing firmware and a read-write memory for temporary data.

Data.

From the earliest microcontrollers to today, six-transistor SRAM is almost always used as the read/write working memory, with a few more transistors per bit used in the register file. FRAM or MRAM could potentially replace it as it is denser which would make it more cost effective.  In addition to the SRAM, some microcontrollers also have internal EEPROM for data storage; and even ones that do not have any (or not enough) are often connected to external serial EEPROM chip (such as the BASIC Stamp) or external serial flash memory chip.  A few recent microcontrollers beginning in 2003 have "self-programmable" flash memory.

Firmware.

The earliest microcontrollers used mask ROM to store firmware. Later microcontrollers (such as the early versions of the Freescale 68HC11 and early PIC microcontrollers) had EPROM memory, which used a translucent window to allow erasure via UV light, while production versions had no such window, being OTP (one-time-programmable). Firmware updates were equivalent to replacing the microcontroller itself, thus many products were not upgradeable.  Motorola MC68HC805 was the first microcontroller to use EEPROM to store the firmware. EEPROM microcontrollers became more popular in 1993 when Microchip introduced PIC16C84 and Atmel introduced an 8051-core microcontroller that was first one to use NOR Flash memory to store the firmware. Today's microcontrollers almost exclusively use flash memory, with a few models using FRAM, and some ultra-low-cost parts still use OTP or Mask-ROM.

A microcontroller (MCU for "microcontroller unit") is a small computer on a single metal-oxide-semiconductor (MOS) integrated circuit (IC) chip. In modern terminology, it is similar to, but less sophisticated than, a system on a chip (SoC); a SoC may include a microcontroller as one of its components. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable input/output peripherals. Program memory in the form of ferroelectric RAM, NOR flash or OTP ROM is also often included on chip, as well as a small amount of RAM. Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications consisting of various discrete chips.

Jednočipový počítač nebo také (mikrokontrolér, MCU, μC) je většinou monolitický integrovaný obvod obsahující kompletní mikropočítač. Jednočipové počítače se vyznačují velkou spolehlivostí a kompaktností, proto jsou určeny především pro jednoúčelové aplikace jako je řízení, regulace apod. Často jsou jednočipové počítače součástí vestavěných (embedded) systémů. Za jednočipový počítač je možno označit i hlavní integrovaný obvod v současných mobilních telefonech.


"Apeiron" as an origin.

The "apeiron" is central to the cosmological theory created by Anaximander, a 6th-century BC pre-Socratic Greek philosopher whose work is mostly lost. From the few existing fragments, we learn that he believed the beginning or ultimate reality ("arche") is eternal and infinite, or boundless ("apeiron"), subject to neither old age nor decay, which perpetually yields fresh materials from which everything we can perceive is derived. "Apeiron" generated the opposites (hot–cold, wet–dry, etc.) which acted on the creation of the world (cf. Heraclitus). Everything is generated from "apeiron" and then it is destroyed by going back to "apeiron", according to necessity. He believed that infinite worlds are generated from "apeiron" and then they are destroyed there again.  His ideas were influenced by the Greek mythical tradition and by his teacher Thales (7th to 6th century BC). Searching for some universal principle, Anaximander retained the traditional religious assumption that there was a cosmic order and tried to explain it rationally, using the old mythical language which ascribed divine control on various spheres of reality. This language was more suitable for a society which could see gods everywhere; therefore the first glimmerings of laws of nature were themselves derived from divine laws. The Greeks believed that the universal principles could also be applied to human societies. The word "nomos" (law) may originally have meant "natural law" and used later to mean man-made law.  Greek philosophy entered a high level of abstraction. It adopted "apeiron" as the origin of all things, because it is completely indefinite. This is a further transition from the previous existing mythical way of thought to the newer rational way of thought which is the main characteristic of the archaic period (8th to 6th century BC). This shift in thought is correlated with the new political conditions in the Greek city states during the 6th century BC.

Roots.

In the mythical Greek cosmogony of Hesiod (8th to 7th century BC) the first primordial god is Chaos, which is a void or gap. Chaos is described as a gap either between Tartarus and the earth's surface (Miller's interpretation) or between earth's surface and the sky (Cornford's interpretation). One can name it also abyss (having no bottom).  Alternately, Greek philosopher Thales believed that the origin or first principle was water. Pherecydes of Syros (6th century BC) probably called the water also "Chaos" and this is not placed at the very beginning.  In the creation stories of Near East the primordial world is described formless and empty. The only existing thing prior to creation was the water abyss. The Babylonian cosmology Enuma Elish describes the earliest stage of the universe as one of watery chaos and something similar is described in Genesis. In the Hindu cosmogony which is similar to the Vedic (Hiranyagarbha) the initial state of the universe was an absolute darkness.  Hesiod made an abstraction, because his original "chaos" is a void, something completely indefinite. In his opinion the origin should be indefinite and indeterminate. The indefiniteness is spatial in early usages as in Homer (indefinite sea). A fragment from Xenophanes (6th century BC) shows the transition from "chaos" to "apeiron": "The upper limit of earth borders on air. The lower limit reaches down to the unlimited. (i.e. the Apeiron)". Either "apeiron" meant the "spatial indefinite" and was implied to be indefinite in kind, or Anaximander intended it primarily 'that which is indefinite in kind' but assumed it also to be of unlimited extent and duration. His ideas may have been influenced by the Pythagoreans: Greek philosophy entered a high level of abstraction making "apeiron" the principle of all things and some scholars saw a gap between the existing "mythical" and the new "rational" way of thought ("rationalism"). But if we follow the course, we will see that there is not such an abrupt break with the previous thought. The basic elements of nature, water, air, fire, earth, which the first Greek philosophers believed that composed the world, represent in fact the mythical primordial forces. The collision of these forces produced the cosmic harmony according to the Greek cosmogony (Hesiod). Anaximander noticed the mutual changes between these elements, therefore he chose something else (indefinite in kind) which could generate the others without experiencing any decay.  There is also a fragment attributed to his teacher Thales: "What is divine? What has no origin, nor end." This probably led his student to his final decision for "apeiron", because the divinity applied to it implies that it always existed. The notion of the temporal infinity was familiar to the Greek mind from remote antiquity in the religious conception of immortality and Anaximander's description was in terms appropriate to this conception. This "arche" is called "eternal and ageless" (Hippolitus I,6,I;DK B2).

Creation of the world.

The "apeiron" has generally been understood as a sort of primal chaos. It acts as the substratum supporting opposites such as hot and cold, wet and dry, and directed the movement of things, by which there grew up all of the host of shapes and differences which are found in the world. Out of the vague and limitless body there sprang a central mass—this earth of ours—cylindrical in shape. A sphere of fire surrounded the air around the earth and had originally clung to it like the bark round a tree. When it broke, it created the sun, the moon and the stars. The first animals were generated in the water. When they came to earth they were transmuted by the effect of the sun. The human being sprung from some other animal, which originally was similar to a fish. The blazing orbs, which have drawn off from the cold earth and water, are the temporary gods of the world clustering around the earth, which to the ancient thinker is the central figure.

Interpretations.

In the commentary of Simplicius on Aristotle's "Physics" the following fragment is attributed direct to Anaximander:  This fragment remains a mystery because it can be translated in different ways. Simplicius comments that Anaximander noticed the mutual changes between the four elements (earth, air, water, fire), therefore he did not choose one of them as an origin, but something else which generates the opposites without experiencing any decay. He mentions also that Anaximander said all these in poetic terms, meaning that he used the old mythical language. The Goddess "Justice" (Dike), appears to keep the order. The quotation is close to the original meanings of the relevant Greek words. The word "dike" (justice) was probably originally derived from the boundaries of a man's land and transmits metaphorically the notion that somebody must remain in his own sphere, respecting the one of his neighbour. The word "adikia" (injustice) means that someone has operated outside of his own sphere, something that could disturb "law and order" ("eunomia"). In Homer's "Odyssey" "eunomia" is contrasted with "hubris" (arrogance). Arrogance was considered very dangerous because it could break the balance and lead to political instability and finally to the destruction of a "city-state".  Aetius (1st century BC) transmits a different quotation:  Therefore, it seems that Anaximander argued about "apeiron" and this is also noticed by Aristotle:  Friedrich Nietzsche claimed that Anaximander was a pessimist and that he viewed all coming to be as an illegitimate emancipation from the eternal being, a wrong for which destruction is the only penance. In accordance to this the world of the individual definite objects should perish into the indefinite since anything definite has to eventually return to the indefinite. His ideas had a great influence on many scholars including Martin Heidegger.  Werner Heisenberg, noted for the creation of quantum mechanics, arrived at the idea that the elementary particles are to be seen as different manifestations, different quantum states, of one and the same "primordial substance". Because of its similarity to the primordial substance hypothesized by Anaximander, his colleague Max Born called this substance "apeiron".  Scholars in other fields, e.g. Bertrand Russell and Maurice Bowra, didn't deny that Anaximander was the first who used the term "apeiron", but claimed that the mysterious fragment is dealing with the balance of opposite forces as central to reality being closer to the quotation transmitted by Simplicius.  There are also other interpretations which try to match both the previous aspects. "Apeiron" is an abstract, void, something that cannot be described according to the Greek pessimistic belief for death. Death indeed meant "nothingless". The dead live like shadows and there is no return to the real world. Everything generated from "apeiron" must return there according to the principle genesis-decay. There is a polar attraction between the opposites genesis-decay, arrogance-justice. The existence itself carries a guilt.  Justice has to destroy everything which is born. There is no external limit that can restrict the activities of men, except the destruction. Arrogance is an expression of the chaotic element of human existence and in a way a part of the rebounding mechanism of order, because pushing it to exertions causes destruction which is also a reestablishment.

Influence on Greek and Western thought.

We may assume that the contradiction in the different interpretations is because Anaximander combined two different ways of thought. The first one dealing with "apeiron" is metaphysical (and can lead to monism), while the second one dealing with mutual changes and the balance of the opposites as central to reality is physical. The same paradox existed in the Greek way of thought. The Greeks believed that each individual had unlimitable potentialities both in brain and in heart, an outlook which called a man to live at the top of his powers. But that there was a limit to his most violent ambitions, that arrogance-injustice ("hubris" or "adikia") could disturb the harmony and balance. In that case justice ("dike") would destroy him to reestablish the order. These ideas are obvious in later Greek philosophers. Philolaus (5th century BC) mentions that nature constituted and is organized with the world from unlimitable ( "apeira", plural of "apeiron") and limitable. Everything which exists in the world contains the unlimited ("apeiron") and the limited. Something similar is mentioned by Plato: Nothing can exist if it doesn't contain continually and simultaneously the limited and the unlimited, the definite and the indefinite.  Some doctrines existing in Western thought, still transmit some of the original ideas: "God ordained that all men shall die", "Death is a common debt". The Greek word "adikia" (injustice) transmits the notion that someone has operated outside of his own sphere, without respecting the one of his neighbour. Therefore, he commits hubris. The relative English word "arrogance" (claim as one's own without justification; ), is very close to the original meaning of the aphorism: "Nothing in excess."

Other pre-Socratic philosophers' ideas about "apeiron".

Other pre-Socratic philosophers had different theories of the "apeiron". For the Pythagoreans (in particular, Philolaus), the universe had begun as an "apeiron", but at some point it inhaled the void from outside, filling the cosmos with vacuous bubbles that split the world into many different parts. For Anaxagoras, the initial "apeiron" had begun to rotate rapidly under the control of a godlike "Nous" (Mind), and the great speed of the rotation caused the universe to break up into many fragments. However, since all individual things had originated from the same "apeiron", all things must contain parts of all other things—for instance, a tree must also contain tiny pieces of sharks, moons, and grains of sand. This alone explains how one object can be transformed into another, since each thing already contains all other things in germ.

Apeiron (; ) is a Greek word meaning "(that which is) unlimited," "boundless", "infinite", or "indefinite" from "a-", "without" and "peirar", "end, limit", "boundary", the Ionic Greek form of "peras", "end, limit, boundary". It is akin to Persian "piramon", meaning "boundary, circumference, surrounding".

Apeiron (z řec. "a-", bez, a "peras", mez, hranice) znamená beztvaré, neomezené, nekonečné a vyskytuje se už u Homéra jako označení pro bezmeznou zemi nebo moře.