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Hypochlorite

In chemistry, hypochlorite is an ion with the chemical formula ClO−. It combines with a number of cations to form hypochlorites, which may be regarded as the salts of hypochlorous acid. Common examples include calcium hypochlorite; the name can refer to esters of the hypothetical hypochlorous acid, namely organic compounds with a ClO– group covalently bound to the rest of the molecule. The principal example is tert-butyl hypochlorite, a useful chlorinating agent. Most hypochlorite salts are unstable in their pure forms, are handled as aqueous solutions, their primary applications are as bleaching and water treatment agents, but they are used in chemistry for chlorination and oxidation reactions. Acidification of hypochlorites generates hypochlorous acid; this exists in an equilibrium with chlorine gas. The equilibrium is subject to Le Chatelier's principle. 2 H+ + ClO− + Cl− ⇌ Cl2 + H2OHypochlorous acid exists in equilibrium with its anhydride. 2 HOCl ⇌ Cl2O + H2O K = 3.55×10−3 dm3 mol−1 Hypochlorites are unstable and many compounds exist only in solution.

Lithium hypochlorite LiOCl, calcium hypochlorite Ca2 and barium hypochlorite Ba2 have been isolated as pure anhydrous compounds. All are solids. A few more can be produced as aqueous solutions. In general the greater the dilution the greater their stability, it is not possible to determine trends for the alkaline earth metal salts, as many of them cannot be formed. Beryllium hypochlorite is unheard of. Pure magnesium hypochlorite cannot be prepared. Calcium hypochlorite has good stability. Strontium hypochlorite, Sr2, is not well characterised and its stability has not yet been determined; the hypochlorite ion is unstable with respect to disproportionation. Upon heating, it degrades to a mixture of chloride and other chlorates: 2 ClO− → 2 Cl− + O23 ClO− → 2 Cl− + ClO−3This reaction is exothermic and in the case of concentrated hypochlorites, such as LiOCl and Ca2, can lead to a dangerous thermal runaway and explosions; the alkali metal hypochlorites decrease in stability down the group. Anhydrous lithium hypochlorite is stable at room temperature.

This is unstable above 0 °C. Potassium hypochlorite is known only in solution. Lanthanide hypochlorites are unstable. Hypochlorite has been used to oxidise cerium from its +3 to +4 oxidation state. Hypochlorous acid. Hypochlorites react with ammonia first giving monochloramine dichloramine, nitrogen trichloride. NH3 + ClO− → HO− + NH2ClNH2Cl + ClO− → HO− + NHCl2NHCl2 + ClO− → HO− + NCl3 Several hypochlorites can be formed by a disproportionation reaction between chlorine and metal hydroxides; the reaction is performed at close to room temperature, as further oxidation will occur at higher temperatures leading to the formation of chlorates. This process is used for the industrial production of sodium hypochlorite and calcium hypochlorite. Cl2 + 2 NaOHNaCl + NaClO + H2O2 Cl2 + 2 Ca2 → CaCl2 + Ca2 + 2 H2OLarge amounts of sodium hypochlorite are produced electrochemically via an un-separated chloralkali process. In this process brine is electrolisyzed to form Cl2; this reaction must be run in non-acidic conditions to prevent chlorine gas from bubbling out of solution: 2 Cl− → Cl2 + 2 e−Cl2 + H2O ⇌ HClO + Cl− + H+Small amounts of more unusual hypochlorites may be formed by a salt metathesis reaction between calcium hypochlorite and various metal sulfates.

This reaction is performed in water and relies on the formation of insoluble calcium sulfate, which will precipitate out of solution, driving the reaction to completion. Ca2 + MSO4 → M2 + CaSO4 Hypochlorite esters are in general formed from the corresponding alcohols, by treatment with any of a number of reagents. Chloroperoxidases are enzymes; this enzyme combines the inorganic substrates chloride and hydrogen peroxide to produce the equivalent of Cl+, which replaces a proton in hydrocarbon substrate: R-H + Cl− + H2O2 + H+ → R-Cl + 2 H2OThe source of "Cl+" is hypochlorous acid. Many organochlorine compounds are biosynthesized in this way. In response to infection, the human immune system generates minute quantities of hypochlorite within special white blood cells, called neutrophil granulocytes; these granulocytes engulf viruses and bacteria in an intracellular vacuole called the phagosome, where they are digested. Part of the digestion mechanism involves an enzyme-mediated respiratory burst, which produces reactive oxygen-derived compounds, including superoxide.

Superoxide decays to oxygen and hydrogen peroxide, used in a myeloperoxidase-catalysed reaction to convert chloride to hypochlorite. Low concentrations of hypochlorite were als

South Troy, Minnesota

South Troy is an unincorporated community in Zumbro Township, Wabasha County, United States. It is located on U. S. Highway 63 about 13 miles north of Rochester. Nearby places include Hammond, Zumbro Falls, Mazeppa and Oronoco. Wabasha County Roads 7 and 11 are nearby. South Troy had a post office from 1858 to 1903. Nearby Zumbro Falls was named Troy in the 1850s; the area south of Zumbro Falls to the Wabasha–Olmsted County line along U. S. 63 was named South Troy. The name of Troy was changed to Zumbro Falls after 1860 because there was a community named Troy in southeast Minnesota at Winona County. South Troy was known for being a home for Laura Ingalls Wilder, the writer of the Little House on the Prairie series of books, her family for a short time in the summer of 1876; this is where Charles and Caroline Ingalls fourth child, their only son, Charles Frederic'Freddy' Ingalls, died at the age of 10 months. Dale – South Troy Cemetery "Frontier Girl Trail – South Troy". Archived from the original on July 22, 2012

Semiconductor package

A semiconductor package is a metal, glass, or ceramic casing containing one or more discrete semiconductor devices or integrated circuits. Individual components are fabricated on semiconductor wafers before being diced into die and packaged; the package provides a means for connecting the package to the external environment, such as printed circuit board, via leads such as lands, balls, or pins. Additionally, it helps dissipate heat produced by the device, with or without the aid of a heat spreader. There are thousands of package types in use; some are defined by international, national, or industry standards, while others are particular to an individual manufacturer. A semiconductor package may have as few as two leads or contacts for devices such as diodes, or in the case of advanced microprocessors, a package may have hundreds of connections. Small packages may be supported only by their wire leads. Larger devices, intended for high-power applications, are installed in designed heat sinks so that they can dissipate hundred or thousands of watts of waste heat.

In addition to providing connections to the semiconductor and handling waste heat, the semiconductor package must protect the "chip" from the environment the ingress of moisture. Stray particles or corrosion products inside the package may degrade performance of the device or cause failure. A hermetic package allows no gas exchange with the surroundings. Manufacturers print -- using ink or laser marking -- the manufacturer's logo and the manufacturer's part number on the package, to make it easier to distinguish the many different and incompatible devices packaged in few kinds of packages; the markings include a 4 digit date code represented as YYWW where YY is replaced by the last 2 digits of the calendar year and WW is replaced by the two-digit week number. To make connections between an integrated circuit and the leads of the package, wire bonds are used, with fine wires connected from the package leads and bonded to conductive pads on the semiconductor die. At the outside of the package, wire leads may be soldered to a printed circuit board or used to secure the device to a tag strip.

Modern surface mount devices eliminate most of the drilled holes through circuit boards, have short metal leads or pads on the package that can be secured by oven-reflow soldering. Aerospace devices in flat packs may use flat metal leads secured to a circuit board by spot welding, though this type of construction is now uncommon. Early semiconductor devices were inserted in sockets, like vacuum tubes; as devices improved sockets proved unnecessary for reliability, devices were directly soldered to printed circuit boards. The package must handle the high temperature gradients of soldering without putting stress on the semiconductor die or its leads. Sockets are still used for experimental, prototype, or educational applications, for testing of devices, for high-value chips such as microprocessors where replacement is still more economical than discarding the product, for applications where the chip contains firmware or unique data that might be replaced or refreshed during the life of the product.

Devices with hundreds of leads may be inserted in zero insertion force sockets, which are used on test equipment or device programmers. Many devices are molded out of an epoxy plastic that provides adequate protection of the semiconductor devices, mechanical strength to support the leads and handling of the package; some devices, intended for high-reliability or aerospace or radiation environments, use ceramic packages, with metal lids that are brazed on after assembly, or a glass frit seal. All-metal packages are used with high power devices, since they conduct heat well and allow for easy assembly to a heat sink; the package forms one contact for the semiconductor device. Lead materials must be chosen with a thermal coefficient of expansion to match the package material. A few early semiconductors were packed in miniature evacuated glass envelopes, like flashlight bulbs. Glass packages are still used with diodes, glass seals are used in metal transistor packages. Package materials for high-density dynamic memory must be selected for low background radiation.

Spaceflight and military applications traditionally used hermetically packaged microcircuits. However, most modern integrated circuits are only available as plastic encapsulated microcircuits. Proper fabrication practices using properly qualified PEMs can be used for spaceflight. Multiple semiconductor dies and discrete components can be assembled on a ceramic substrate and interconnected with wire bonds; the substrate bears leads for connection to an external circuit, the whole is covered with a welded or frit cover. Such devices are used when requirements exceed the performance available in a single-die integrated circuit, or for mixing analog and digital functions in the same package; such packages are expensive to manufacture, but provide most of the other benefits of integrated circuits. A modern example of multi-chip integrated circuit packages would be certain models of microprocessor, which may include separate dies for such things as cache memory within the same package

Nigel Bloy

Nigel Clement Francis Bloy was an English cricketer and Royal Air Force officer. Bloy was a left-handed batsman, he was born in Devon. Bloy reached the age of active service in the British Armed Forces during the Second World War, he was mentioned in a supplement to the London Gazette in 1943 as having been placed on Royal Air Force Volunteer Reserve. By 1950 he was still active within the Royal Air Force and in December 1949, he had been promoted to Flying Officer. Bloy made his first-class debut for Oxford University against Gloucestershire in 1946, he played 28 first-class matches for the University from 1946 to 1948, with his final appearance for it coming against Surrey. Bloy scored 862 runs for the University, at a batting average of 22.10, with two half centuries and a high score of 77. His highest score for the University came against Yorkshire in his second first-class match in 1946, he was dismissed in this innings by Len Hutton. He made further first-class appearances for the Free Foresters in 1951 against Oxford University and in 1954 and 1958 against Ireland while touring with the Marylebone Cricket Club.

Bloy played for the Gloucestershire Second XI, before joining Devon where he represented the county in the Minor Counties Championship from 1951 to 1957. He played Minor counties cricket for Dorset from 1958 to 1961, he died in Sherborne, Dorset on 7 January 1989. Nigel Bloy at ESPNcricinfo Nigel Bloy at CricketArchive

Vijayalaya Chola

Vijayalaya Chola was a king of South India who founded the imperial Chola Empire. He ruled over the region to the north of the river Kaveri; the ancient Chola kingdom once famous in Tamil literature and in the writings of Greek merchants and geographers faded into darkness after c. 300 CE. Cholas during this period completely disappeared from their native land, they seem to have held on to their old capital city of Urayur. This'dark' age of Tamil history came to an end with the ascendency of the Pandyas and the Pallavas; the Cholas had to wait for another three centuries until the accession of Vijayalaya in the second quarter of the ninth century to re-establish their dynasty. We know little of the fate of the Cholas in this long interval. What is certain however is that when the power of Cholas fell to the lowest ebb and that of the Pandyas and Pallavas rose to the north and south of them, this ancient dynasty was compelled to seek refuge and patronage under their more successful rivals; the Cholas, though not prominent or powerful as they were earlier were not in danger of extinction and continued to hold sway over a limited area consisting of what are the districts of Mayiladuturai, Thanjavur and Pudukkottai in modern Tamil Nadu.

Making use of the opportunity during a war between Pandyas and Pallavas, Vijayalaya rose out of obscurity and captured Thanjavur. At this time there was a great struggle going on between the Pallavas and the Pandyas for the political supremacy of South India. In this disturbed state of affairs, Vijayalaya seems to have found a good opportunity to defeat the Pandyas, make himself the ruler of Thanjavur and the surrounding Chola country, he defeated the Pallavas. Vijayalaya Chola conquered Thanjavur from Elango Mutharaiyar, the final ruler of Mutharaiyar dynasty, it is said that in the year 852 CE Vijayalaya Chola defeated the latter. Making use of the opportunity during a war between Pandyas and Pallavas, Vijayalaya rose and established the Chola kingdom at Thanjavur with help of Muttaraiyar king Sattan Paliyilli. Cholas became so powerful that the Pallavas were wiped out from the Thanjavur region at a stage. After Vijayalaya’s capture of Thanjavur, the Pandyan king Varagunavarman II became a subordinate ally of the Pallava Nandivarman III.

Nandhivarman wished to curtail the growing influence of Chola power under Vijayalaya and called upon the Varagunavarman to help suppress Vijayalaya. Varaguna led an expedition into the Chola country; the Pandyan army reached the north bank of the Kaveri near Thanjavur and for a while the Chola revival looked short lived. Vijayalaya, by this time a veteran of many battles, was an invalid; the crown prince Aditya. Vijayalaya was succeeded after his death c. 871 CE by his son Aditya I. The Tiruvalangadu plates state that Vijayalaya captured the city of Tanjavur and made it his capital and that he built in it a temple to the goddess Nisumbhasudani; the Kanyakumari inscription states. Vijayalaya took the title of Parakesarivarman. Chola kings succeeding him took the titles of Rajakesari in turns; this is to acknowledge their supposed ancestors Parakesari and Rjakesari. Narttamalai, Pudukkottai has a solesvara temple attributed to Vijayalaya. Tamil And Sanskrit Inscriptions Chiefly Collected In 1886 - 87, E. Hultzsch, Ph.

D. Published by Archaeological Survey of India, New Delhi Nilakanta Sastri, K. A.. The CōĻas, University of Madras, Madras. Nilakanta Sastri, K. A.. A History of South India, OUP, New Delhi

Sylvan Byck

Sylvan Byck was the comic strip editor for King Features Syndicate for over 30 years, in which position he evaluated "up to 2000 comics submissions a year." After graduating from the Pratt Institute, Byck worked for various newspapers, including as an editorial cartoonist at the Brooklyn Times-Union and the Seattle Times. In 1937, Byck joined King Features Syndicate. In 1945, he became King's comics editor. Among the multiple projects that he purchased were Mort Walker's Beetle Bailey and Hi and Lois, for which Byck and Walker independently suggested recruiting Dik Browne as illustrator; as well, Byck suggested. Other strips in whose launching he was "instrumental" included Buz Sawyer, Hazel, The Lockhorns, Inside Woody Allen, the Archie comic strip. Byck was responsible for ensuring the continuation of strips after their original creators were no longer available, including Little Iodine and Rip Kirby. However, in the case of Steve Canyon, Byck "dismissed the possibility of a successor" to the strip's creator Milt Caniff, on the grounds that Caniff "could never be imitated".

In 1978, Byck retired, was succeeded by Bill Yates. In 1977, Inklings Magazine called Byck "the most influential man in newspaper comics in our generation", in 1979, the National Cartoonists Society awarded him the Silver T-Square Award. Mort Walker said that, of all the editors he met when he was beginning his career, Byck was "the most helpful and encouraging". Alex Toth stated that, when he applied to be the new illustrator for the Perry Mason comic strip, Byck told him that he would be required to imitate Alex Raymond's style rather than use his own. Stan Drake reported having been chastised by Byck for including too much emotional expression when drawing the faces of characters in The Heart of Juliet Jones