Ochroma pyramidale, commonly known as the balsa tree, is a large, fast-growing tree native to the Americas. It is the sole member of the genus Ochroma. The tree is famous for its wide usage in woodworking, due to its softness and its high strength compared to its low density. The name balsa is the Spanish word for "raft."

A deciduous angiosperm, Ochroma pyramidale can grow up to 30 m tall, and is classified as a hardwood despite the wood itself being very soft; it is the softest commercial hardwood and is widely used because of its light weight.

Balsa trees grow extremely fast, often up to 27 metres in 10-15 years, and do not usually live beyond 30 to 40 years. They are often cultivated in dense patches, with Ecuador supplying 95% or more of the commercial balsa. The wood from these trees is highly valuable due to its high strength-to-weight ratio, which is achieved through a kiln-drying process that leaves the wood's cells hollow and empty.

Balsa wood is popular for light, stiff structures in model bridge tests, model buildings, and construction of model aircraft. It is also used in the manufacturing of wooden crankbaits for fishing, makeshift pens for calligraphy, composites, surfboards, boats, "breakaway" props for theatre and television, and even in the floor pans of the Chevrolet Corvette. Balsa wood played a historical role in Thor Heyerdahl's Kon-Tiki expedition where it was used to build the raft. Balsa wood is also popular in arts such as whittling and surfing, and in the making of baroque-style picture frames due to its ease of shaping.

Biology

A member of the mallow family, Ochroma pyramidale is native from southern Mexico to southern Brazil, but can now be found in many other countries (Papua New Guinea, Indonesia, Thailand, Solomon Islands). It is a pioneer plant, which establishes itself in clearings in forests, either man-made or where trees have fallen, or in abandoned agricultural fields. It grows extremely rapidly, up to  in 10–15 years. The speed of growth accounts for the lightness of the wood, which has a lower density than cork. Trees generally do not live beyond 30 to 40 years.

Flowers are produced from the third year onwards, typically at the end of the rainy season when few other trees are in flower. The large flowers open in the late afternoon and remain open overnight. Each may contain a pool of nectar up to  deep. Daytime pollinators include capuchin monkeys. However, most pollination occurs at night. The main pollinators were once thought to be bats, but recent evidence suggests that two nocturnal arboreal mammals, the kinkajou and the olingo, may be the primary pollinators.

It is evergreen or dry-season deciduous, with large , weakly palmately lobed leaves.

Being a deciduous angiosperm, balsa is classified as a hardwood despite the wood itself being very soft; it is the softest commercial hardwood.

Cultivation

Ecuador supplies 95% or more of commercial balsa. In recent years, about 60% of the balsa has been plantation-grown in densely packed patches of around 1000 trees per hectare (compared to about two to three per hectare in nature). The trees are harvested after six to ten years of growth.

Uses

Balsa lumber is very soft and light, with a coarse, open grain. The density of dry balsa wood ranges from 40 to 475 kg/m3, with a typical density around 160 kg/m3. Balsa is the softest wood ever measured using the Janka hardness test (22 to 167 lbf). The wood of the living tree has large cells that are filled with water. This gives the wood a spongy texture. It also makes the wood of the living tree not much lighter than water and barely able to float. For commercial production, the wood is kiln-dried for about two weeks, leaving the cells hollow and empty. The large volume-to-surface ratio of the resulting thin-walled, empty cells gives the dried wood a large strength-to-weight ratio because the cells are mostly air. Unlike naturally rotted wood, which soon disintegrates in the rainforests where balsa trees grow, the cell walls of kiln-seasoned balsa wood retain their strong structure of cellulose and lignin.

Because it is low in density but high in specific strength, balsa is a very popular material for light, stiff structures in model bridge tests, model buildings, and construction of model aircraft; all grades are usable for airworthy control line and radio-controlled aircraft varieties of the aeromodeling sports, with the lightest "contest grades" especially valuable for free-flight model aircraft. However, it is also valued as a component of full-sized light wooden aeroplanes, most notably the World War II de Havilland Mosquito.

Balsa is used to make wooden crankbaits for fishing, especially Rapala lures.

Sticks of dried balsa are useful as makeshift pens for calligraphy when commercial metal nibs of the desired width are not available.

Balsa wood is often selected as a core material in composites. Because O. pyramidale grows quickly and tolerates poor soils it is lower in cost per performance compared to polymer foams like EPS while having better tensile strength than typical foams. For example, the blades of wind turbines are commonly constructed of many balsa plywood cores and internal spars covered with resin infused cloth on both sides. In table tennis bats, a balsa layer is typically sandwiched between two pieces of thin plywood made from other species of wood. Balsa wood is also used in laminates together with glass-reinforced plastic (fiberglass) for making high-quality balsa surfboards and for the decks and topsides of many types of boats, especially pleasure craft less than 30 m in length. On a boat, the balsa core is usually end-grain balsa, which is much more resistant to compression than if the soft balsa wood were laid lengthwise.

Balsa is also used in the manufacture of "breakaway" wooden props such as tables and chairs that are designed to be broken as part of theatre, movie, and television productions.

The fifth and sixth generations of the Chevrolet Corvette had floor pans composed of balsa sandwiched between sheets of carbon-fiber-reinforced plastic.

Norwegian scientist and adventurer Thor Heyerdahl, convinced that early contact between the peoples of South America and Polynesia was possible, built the raft Kon Tiki from balsa logs, and upon it his crew and he sailed the Pacific Ocean from Peru to the Polynesian Tuamotu Archipelago in 1947. However, the Kon Tiki logs were not seasoned and owed much of their (rather slight) buoyancy to the fact that their sap was of lower density than sea water. This serendipitously may have saved the expedition, because it prevented the seawater from waterlogging the wood and sinking the raft.

Balsa wood is also a popular wood type used in the arts of whittling, and surfing. In the making of picture frames, balsa was often used in a baroque style because of the ease of shaping the design.

Balsa leaf tending to gold amalgamation. Supported with Manihot esculenta Crantz (bitter cassava) the gravity concentration of gold, attracting even small gold particles, seems to be a viable methode to substitute mercury in gold extraction.

Gallery

See also
 Tilia, another tree producing lightweight lumber (especially Tilia americana)
 Paulownia

References

External links

Bombacoideae
Malvaceae genera
Monotypic Malvales genera
Plants described in 1920
Trees of Mexico
Trees of Central America
Trees of Peru
Trees of South America
Trees of the Caribbean

Ochroma


In the United States, a presidential primary is a series of elections and caucuses within a political party. They are held to choose the party's candidate for the presidential election. This process was never included in the United States Constitution; it was created over time by the political parties. Some states hold only primary elections, some hold only caucuses, and others use a combination of both.

These primaries and caucuses are staggered generally between either late-January or early-February, and mid-June before the presidential election in November. The primary elections are run by state and local governments.

Other websites
 Fairvote.org

United States presidential primary


The White Citizens' Council was an American group of people who believed that white people were better than black people (white supremacy). It began on July 11, 1954.  After 1956, it was called the Citizens' Councils of America.  With about 60,000 members, mostly in the South, many people knew the group because it opposed racial integration during the 1950s and 1960s. It responded to integration efforts with economic boycotts and other intimidation against black activists, including depriving them of jobs.  The WCC was a part of the "massive resistance" in the South against court decisions that required racial integration.

Federal civil rights legislation passed in the mid-1960s over the opposition of the WCC. By the 1970s, the federal government was working hard to enforce those laws. So, the influence of the WCC dropped very much. People in the WCC went on to found the Council of Conservative Citizens in the 1985.

References

Further reading

Geary, Daniel and Sutton, Jennifer. "Resisting the Wind of Change: The Citizens' Councils and European Decolonization," in Cornelius A. van Minnen and Manfred Berg, eds., The U.S. South and Europe, University of Kentucky Press, 2013.

Other websites
The Citizens' Council - Historical resource website by Edward Sebesta, with digitized copies of the full run of The Citizens Council newspaper, 1955–1961. Originally a publication of the Mississippi Citizens' Council, the monthly publication became the official paper of the Citizens' Councils of America in October 1956.
Available in PDF from Internet Archive.
"Civil Rights Documentation Project" , University of Southern Mississippi
Dr. John Dittmer, "'Barbour is an Unreconstructed Southerner': Prof. John Dittmer on Mississippi Governor's Praise of White Citizens' Councils", 22 December 2010 video report by Democracy Now!
 "Schwerner, Chaney, and Goodman: The Struggle for Justice" , American Bar Association

American civil rights
1954 establishments in the United States

Citizens' Councils


James McCray was an American operatic tenor and voice teacher.

Life and career
Born in Ohio, McCray served in the United States Marine Corps during the Korean War before entering the Mannes School of Music in New York City where he was a pupil of Patricia Neway. In 1962 he won the Metropolitan Opera National Council Auditions. In the Spring of 1965 he was active with the Concert Opera Association at Philharmonic Hall in NYC, singing Chekalinsky in The Queen of Spades and Francesco in the United States premiere of Hector Berlioz's Benvenuto Cellini. The following summer he appeared at the Stratford Festival of Canada as Jimmy Mahoney in Kurt Weill's Rise and Fall of the City of Mahagonny.

From 1965-1968 McRay was active with the Israel National Opera; performing such roles as Canio in Pagliacci, Cavaradossi in Tosca, Don Jose in Carmen, Manrico in Il trovatore, Riccardo in Un ballo in maschera, and Samson in Samson et Dalila. In 1969 he made his debut at the New York City Opera as Vladimir Igorevich in Alexander Borodin's Prince Igor. The following year he sang the role of Count Loris Ipanov in Victorien Sardou's Fedora with the Opera Orchestra of New York, conductor Eve Queler, and soprano Judith de Paul in the title role. In 1971 he portrayed the role of Dick Johnson in La fanciulla del West at the Minnesota Opera. That same year he performed the role of Manrico with Irene Dalis and Betty Allen alternating in the role of Azucena for the San Francisco Opera. In 1972 he created the role of Ken in the world premiere of Harold Farberman's The Losers which was commissioned by the Juilliard School.

From 1974-1976 McCray performed annually with the Greater Miami Opera Association, portraying roles in productions of Robert Ward's The Crucible, Richard Wagner's The Flying Dutchman, and Giuseppe Verdi's Otello under conductor Emerson Buckley. In 1977 he had a particular triumph at the Seattle Opera as Siegfried in Wagner's The Ring Cycle.

After retiring from singing, McCray lived and taught in The Hague, Netherlands at the McCray International Studio for Vocal Arts.  He died in January 2018.

References

External links
Official Website of James McCray

20th-century births
2018 deaths
American operatic tenors
The New School alumni
Winners of the Metropolitan Opera National Council Auditions
Musicians from Ohio

James McCray


Broccoflower is a vegetable. It is either of two plants of the species Brassica oleracea with light green heads.  The part that can be eaten is the young flower head (inflorescence) of the plant.

There are two forms of Brassica oleracea that can be called broccoflower. One is shaped like regular cauliflower. The other has a spiky appearance. They have a color like that of broccoli.

Vegetables
Brassica oleracea

Broccoflower


is a Japanese variant of hot pot.  The dish uses thinly sliced meat and vegetables, and it is usually served with dipping sauces of ponzu and/or sesame sauce. The kinds of meats used are beef and pork, the kind of vegetables are hakusai (Japanese white cabbage), shungiku, Japanese enoki mushrooms, and Welsh onions.Today, there are many kinds of shabu-shabu. In addition to meat, seafood is used this dishes such as globefish, octopus and crab.shabu-shabu is a savory dish.  It is considered a winter dish but is eaten year-round.
Today, there are many kinds of shabu-shabu. There is some kinds of Shabushabu. In hokkaido, there is "Takosyabu" which uses octopus. In Nagoya, there is "Torisyabu" which uses Nagoyacotin" In Toyama, there is "Sakesyabu" which uses salmon. In Kagoshima, there is ""Kurobutashabu" which use "Kagoshima black pig".

Japanese food

Shabu shabu


Villi (singular is villus) are small, finger-like structures in the small intestine.  They help to absorb digested food. Each villus has microvilli which increase the surface area of the intestinal walls. A larger surface area allows nutrients to be taken in more quickly.

The food (proteins, fats and carbohydrates) has already been broken down by enzymes called proteases, lipases and amylases. The amino acids and sugars (breakdown molecules of proteins and carbohydrates) go first into the blood stream. Then they are processed by the liver, which acts like a chemical factory for the body. Lipid substances (such as cholesterol) go first into the lymphatic system, and eventually into the blood stream and the liver.

Anatomy of the digestive system

Villi


A poverty map is a map which provides a detailed description of the spatial distribution of poverty and inequality within a country. It combines individual and household (micro) survey data and population (macro) census data with the objective of estimating welfare indicators for specific geographic area as small as village or hamlet.

Recent advances in geographic information systems (GIS), databases and computer aided software engineering make poverty mapping possible, where data can be presented in the form of maps and overlaying interfaces for cross-comparisons.  Spatial analysis and benchmarking are also applied to assess the relationships between the two sets of micro and macro data according to their geographic location.

See also
Life and Labour of the People in London

References

External links
Mapping poverty in America

Measurements and definitions of poverty
Economic geography
Map types

Poverty map


In logic, a quantifier is a way to state that a certain number of elements fulfill some criteria.  For example, every natural number has another natural number larger than it. In this example, the word "every" is a quantifier. Therefore, the sentence "every natural number has another natural number larger than it" is a quantified expression.

Quantifiers and quantified expressions are a useful part of formal languages. They are useful because they let rigorous statements claim how widespread a criteria is. Two basic kinds of quantifiers used in predicate logic are universal and existential quantifiers. A universal quantifier states that all the elements considered fulfill the criteria. The universal quantifier is symbolized with "∀", an upside down "A", to stand for "all". An existence quantifier (symbolized with "∃") states that at least one element considered fits the criteria. The existential quantifier is symbolized with "∃", a backwards "E", to stand for "exists".

Quantifiers are also used in natural languages. Examples of quantifiers in English include for all, for some, many, few, a lot, and no.

Mathematics
This statement is infinitely long:
 1 · 2 = 1 + 1, and 2 · 2 = 2 + 2, and 3 · 2 = 3 + 3, ..., and 100 · 2 = 100 + 100, and ..., etc.

This is a problem for formal languages, since a formal statement needs to be finite in length. These problems can be avoided by using universal quantification. This results in the following compact statement:
 For each natural number n, n · 2 = n + n.
In the same way, we can shorten an infinite sequence of statements joined by or such as:
 1 is equal to 5 + 5, or 2 is equal to 5 + 5, or 3 is equal to 5 + 5, ... , or 100 is equal to 5 + 5, or ..., etc.
by rewriting it using existential quantification:
 For at least one natural number n, n is equal to 5+5.

Notation

The two quantifiers most widely used are the universal quantifier and the existence quantifier.

The universal quantifier is used to claim that for elements in a set, the elements all match some criteria. Usually, this statement "for all elements" is shortened to an "A" flipped upside down, which is "∀".

The existential quantifier is used to claim that for elements in a set, there exists at least one element that matches some criteria. Usually, this statement "there exists an element" is shortened to an "E" flipped upside down, which is "∃".

English statements can be often rewritten using symbols, predicates representing criteria, and quantifiers. One example is "Each of Peter's friends either likes to dance or likes to go to the beach". Let X be the set of all Peter's friends. Let P(x) be the predicate "x likes to dance". Let Q(x) be the predicate "x likes to go to the beach". We can rewrite the example using formal notation as . The statement can be read as "For every x that is a member of X, P applies to x or Q applies to x."

There are other ways to use quantifiers in formal language. Each of the following statements below says the same thing as :

There are a few more ways to represent the universal quantifier:

Several statements above explicitly include X, the set of elements that the quantifier applies to. This set of elements is also known as the range of quantification, or the universe of discourse. Some of the statements above do not include such a set. In this case, the set will have to be specified before the statement. For example, "x is an apple" must be stated before . In this case, we are making a statement that at least one apple fits the predicate P.

Using quantifiers formally does not require using the symbol x. In fact, other symbols, such as y and z, can also be used. However, one must be careful not to use the same symbol to refer to two different things.

Nesting
It is important to put quantifiers in the right order. Below is an example of an English sentence showing how meaning changes with order:
For every natural number n, there exists a natural number s such that s = n2.
This statement is true. It states that every natural number has a square. However, if we turn the order of the quantifiers around:
There exists a natural number s, such that for every natural number n, s = n2.
then the statement is false. It claims that there is one natural number s that is the square of every natural number.

In certain circumstances, changing the order of quantifiers does not change the meaning of the statement. For instance:
There exists a natural number x, and there exists a natural number y such that x = y2.

Other quantifiers
There are also less common quantifiers used by mathematicians.

An example is the solution quantifier. It is used to state which elements solve a particular equation. The solution quantifier is represented by a § (section sign). For example, the following statement claims the squares of 0, 1 and 2 are smaller than 4.  :

Other quantifiers include:
There are many elements such that...
There are few elements such that...
There are infinitely many elements such that...
For all but finitely many elements... (sometimes expressed as "for almost all elements...").
There are uncountable many elements such that...
For all but countably many elements...

History

Term logic was developed by Aristotle. It was an early form of logic, and included quantification. The use of quantification was closer to that of natural language. This meant that statements in term logic with quantifiers were less suited for formal analysis. Term logic included quantifiers for All, Some  and No (none) in 4th century BC.

In 1879, Gottlob Frege created a notation for universal quantification. Unlike the modern notation, he would represent a universal quantification by writing a variable over a dimple in an otherwise straight line. Frege did not create a notation for existential quantification. Instead, he combined universal quantification and a number of negations to make an equivalent statement. Frege's use of quantification was not widely known until Bertrand Russell's 1903 Principles of Mathematics.

In 1885, Charles Sanders Peirce and his student Oscar Howard Mitchell also created a notation for universal and existential quantifiers. They wrote Πx and Σx where we now write ∀x and ∃x. Pierce's notation was used by many mathematicians into the 1950s.

In 1897, William Ernest Johnson and Giuseppe Peano created another notation for universal and existential quantification. They were influenced by Pierce's previous quantification notation. Johnson and Peano used the simple (x) for universal quantification, and ∃x for existential quantification. Peano's influence on math spread this notation across Europe.

In 1935, Gerhard Gentzen created the ∀ symbol for universal quantification. It was not widely used until the 1960s.

Related pages
Determiner
First order logic
Rule of inference

References

Logic

Logical quantifier


In cultural anthropology and sociology, redistribution refers to a system of economic exchange involving the  centralized collection of goods from members of a group followed by the redivision of those goods among those members. It is a form of reciprocity. Redistribution differs from simple reciprocity, which is a dyadic back-and-forth exchange between two parties. Redistribution, in contrast, consists of pooling, a system of reciprocities. It is a within group relationship, whereas reciprocity is a between relationship. Pooling establishes a centre, whereas reciprocity inevitably establishes two distinct parties with their own interests. While the most basic form of pooling is that of food within the family, it is also the basis for sustained community efforts under a political leader.

Sahlins argues that generalized reciprocity within families by elders may be a "starting mechanism" for more general hierarchy, by placing many in the giver's debt. This leads to the question, "when does reciprocity give way to redistribution." Sahlins argues that chiefly redistribution is not different in principle and nothing but a highly organized form of kinship-rank reciprocity. Others, such as French Marxist anthropologist Claude Meillassoux, used the development of ranked kin redistribution from generalized reciprocity as the basis for a lineage mode of production found in western African chiefdoms and kingdoms.
An elaborate example of this in a non-market society is the potlatch, where large amounts of personal resources are ceremonially given away to others in the community according to social status, with the tacit expectation that other members of the community would themselves give away large amounts of their own property in the future.

Bähre argued that redistribution is a central mechanism in capitalist economies. In South Africa, many find themselves in a post-Fordist economy that is characterised by redistribution through the state (development aid, welfare), through markets (for example commercial insurance) and through religious institutions (neo-Pentecostal churches).

In modern mixed market economies, the central form of redistribution is facilitated through taxation by the state. Redistribution of property therefore occurs where properties are allocated back to individuals or groups within society either through the provision of public services or directly through welfare benefits.

See also
 Classless society
 Equality of outcome
 Non-market economics
 Economic anthropology

References

Cultural anthropology

Redistribution (cultural anthropology)


The Ceylon Workers' Congress (CWC) (;  Lanka Kamkaru Kongrasaya) is a political party in Sri Lanka that has traditionally represented Sri Lankan Tamils of Indian origin working in the plantation sector of the economy.

History
The CWC was formed by Peri Sundaram and G. R. Motha as an Indian Estates Workers Trade Union in 1950. It was an outgrowth of the Ceylon Indian Congress (CIC), formed 15 July 1939. In 1950 the CIC changed its name to the Ceylon Workers Congress (CWC) and became the largest trade union in the country. Another trade union, the Democratic Workers Congress (DWC), was formed in 1956 as a breakaway faction of the CWC as a result of leadership rivalries between the president, S. Thondaman, and the general secretary A. Aziz. The former retained control of the CWC to date. Thondaman has been the dominant trade union leader of the Indian Tamil workers for nearly four decades. As president of the Ceylon Indian Congress, he contested the Nuwara Eliya seat at the 1947 general election and won. His party put forward eight candidates in the plantation electorates and seven of them were returned, they were Thondaman, S. M. Subbaiah (Badulla), G. R. Motha (Maskeliya), K. Rajalingam (Nawalapitiya), K. Kumaravelu (Kotagala), C. V. Velupillai (Talawakelle) and D. Ramanujam (Alutnuwara).

Organisation
The political potentiality of the Indian Tamil workers and the CIC led by Thondaman were viewed as threats to the power of the ruling United National Party. Another view was that the enfranchisement of the Indian workers would interfere with the representation of the Kandyan Sinhalese in the legislature. However, the main reason for the disenfranchisement was the fear of political leaders like Senanayake (and even Ponnambalam) that the estate sector would become a prey to the Marxist movement. The left movement was militant and had a public image which concealed that its political strength was minuscule. However, the political leaders of the era had a more pessimistic prognosis.

Even though the Donoughmore Constitution had granted universal franchise to Ceylonese, this was not applied to the Indian Estate Tamils, due to opposition from caste-conscious Colombo Tamils, vote conscious Kandyan Sinhalese, as well as due to the general opposition to any form of universal franchise. The latter was named "mob rule" by Arunachalam Ponnambalam. Thus, even by 1939, only a fraction of the Hill-country Tamils had been granted the franchise. The fear of Marxist control of the estates, as well as the pressure of Kandyan politicians, led to attempts to not to extend citizenship to the Indian Tamils of the newly independent nation, except under very stringent conditions. In effect, the Ceylon Citizenship Act of 1948 and the Indian and Pakistani Residents (Citizenship) Act No.3 of 1949 were passed by the Sri Lankan Parliament and simply reinforced the status quo of the harsher pre-Donoughmore era prior to Universal Franchise (see Sri Lanka Tamils (Indian origin) for more details of dis-enfranchisement).

Thondaman opposed those laws and argued that most of the Indians were permanent residents and were the sons and daughters of the soil as are the Sinhalese or the "Malabar Tamils". The Marxist politicians criticised the move as an act of capitalist-imperialist lackeys, while S.J.V. Chelvanayakam the criticised the government as a Sinhala extremist regime, and branded Ponnambalam a traitor.

Thondaman's political organization staged a non-violent satyagraha campaign against the implementation of citizenship laws and boycotted them for a period of time. Since 1952, the Indian Tamils could not elect any representative to the Parliament as their voting strength was drastically reduced.

Thondaman supported the Sri Lanka Freedom Party in the 1960 elections and, after the victory of this party, was appointed to the House of Representative as a nominated Member of Parliament. On 3 December 1964, Thondaman declined to vote on a motion connected with the Governor General's Throne Speech. This brought about the downfall of the SLFP government led by Sirimavo Bandaranaike.

In the March 1965 elections, Thondaman shifted to the UNP to protest against the terms of the Indo-Ceylon Agreement of October 1964. After the victory of the UNP in 1965, S. Thondaman and Veloo Annamalay was named as appointed Members of Parliament.

He was out of Parliament from 1970 to 1977 after the defeat of the UNP in the general election of 1970. During this period the CWC under his leadership gradually allied itself with the major Tamil political parties and subscribed to form the Tamil United Front (TUF). He was also elected a leader of the triumvirate leadership of this Tamil political organization.

In May 1975, the TUF stressed that its objective was the setting up of the separate free, secular, sovereign, socialist state of Tamil Eelam and renamed itself into Tamil United Liberation Front (TULF). Thondaman did not want to subscribe to this new separatist policy of the TULF and withdrew from it.

He shifted his loyalties towards the United National Party which came to power in 1977. He served on the select committee for the revision of the constitution in 1978. In September 1978, he was invited by President J. R. Jayawardhane to join the Cabinet, which he accepted after the Executive Council of the Ceylon Workers Congress decided to do so.

Since 1978, Thondaman has served as a Cabinet minister under Presidents J. R. Jayawardhane, R.Premadasa and since 1995 under president Chandrika Bandaranaike.

When he joined the UNP government, he explained that he owed his position to the CWC, and the CWC's policy was to get citizenship for the stateless and better working conditions for estate labour.

At the last legislative elections, held on 2 April 2004, the party was a minor partner in the UNP-dominated United National Front that won 37.8% of the popular vote and 82 out of 225 seats.

References

1939 establishments in Ceylon
Ceylon in World War II
ICFTU Asia and Pacific Regional Organisation
Political parties established in 1939
Political parties in Sri Lanka
Tamil political parties in Sri Lanka
Trade unions established in 1939
Trade unions in Sri Lanka
United People's Freedom Alliance

Ceylon Workers' Congress


In accounting/accountancy, adjusting entries are journal entries usually made at the end of an accounting period to allocate income and expenditure to the period in which they actually occurred. The revenue recognition principle is the basis of making adjusting entries that pertain to unearned and accrued revenues under accrual-basis accounting. They are sometimes called Balance Day adjustments because they are made on balance day.

Based on the matching principle of accrual accounting, revenues and associated costs are recognized in the same accounting period. However the actual cash may be received or paid at a different time.

Types of adjusting entries
Most adjusting entries could be classified this way:

Prepayments
Adjusting entries for prepayments are necessary to account for cash that has been received prior to delivery of goods or completion of services.  When this cash is paid, it is first recorded in a prepaid expense asset account;  the account is to be expensed either with the passage of time (e.g. rent, insurance) or through use and consumption (e.g. supplies).

A company receiving the cash for benefits yet to be delivered will have to record the amount in an unearned revenue liability account.  Then, an adjusting entry to recognize the revenue is used as necessary.

Example
Assume a magazine publishing company charges an annual subscription fee of $12. The cash is paid up-front at the start of the subscription. The income, based on sales basis method, is recognized upon delivery. Therefore, the initial reporting of the receipt of annual subscription fee is indicated as:

                         Debit  |  Credit
                         ----------------
 Cash                     $12   |
   Unearned Revenue             |   $12
                                |

The adjusting entry reporting each month after the delivery is:

                         Debit  |  Credit
                         ----------------
 Unearned Revenue           $1  |
   Revenue                      |    $1
                                |

The unearned revenue after the first month is therefore $11 and revenue reported in the income statement is $1.

Accruals
Accrued revenues are revenues that have been recognized (that is, services have been performed or goods have been delivered), but their cash payment have not yet been recorded or received. When the revenue is recognized, it is recorded as a receivable.

Accrued expenses have not yet been paid for, so they are recorded in a payable account.  Expenses for interest, taxes, rent, and salaries are commonly accrued for reporting purposes.

An income which has been earned but it has not been received yet during the accounting period. Incomes like rent, interest on investments, commission etc. are examples of accrued income.

Estimates
A third classification of adjusting entry occurs where the exact amount of an expense cannot easily be determined.  The depreciation of fixed assets, for example, is an expense which has to be estimated.

The entry for bad debt expense can also be classified as an estimate.

Inventory
In a periodic inventory system, an adjusting entry is used to determine the cost of goods sold expense.  This entry is not necessary for a company using perpetual inventory.

See also
 Accruals & Deferrals
 Accounting methods
 US Generally Accepted Accounting Principles
 International Financial Reporting Standards

External links
Further reading:
Adjusting Entries  Explanation with examples.
Adjusting Entries

Accounting terminology

Adjusting entries


Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, phase and frequency of an analog signal.

Analog signals vary over a continuous range of possible values which means that electronic noise and interference may be introduced. Thus with analog, a moderately weak signal becomes snowy and subject to interference. In contrast, picture quality from a digital television (DTV) signal remains good until the signal level drops below a threshold where reception is no longer possible or becomes intermittent.

Analog television may be wireless (terrestrial television and satellite television) or can be distributed over a cable network as cable television.

All broadcast television systems used analog signals before the arrival of DTV.  Motivated by the lower bandwidth requirements of compressed digital signals, beginning in the 2000s, a digital television transition is proceeding in most countries of the world, with different deadlines for the cessation of analog broadcasts. Several countries have made the switch already, with the remaining countries still in progress mostly in Africa and Asia.

Development

The earliest systems of analog television were mechanical television systems that used spinning disks with patterns of holes punched into the disc to scan an image. A similar disk reconstructed the image at the receiver. Synchronization of the receiver disc rotation was handled through sync pulses broadcast with the image information. Camera systems used similar spinning discs and required intensely bright illumination of the subject for the light detector to work. The reproduced images from these mechanical systems were dim, very low resolution and flickered severely.

Analog television did not begin in earnest as an industry until the development of the cathode-ray tube (CRT), which uses a focused electron beam to trace lines across a phosphor coated surface. The electron beam could be swept across the screen much faster than any mechanical disc system, allowing for more closely spaced scan lines and much higher image resolution. Also, far less maintenance was required of an all-electronic system compared to a mechanical spinning disc system.  All-electronic systems became popular with households after World War II.

Standards

Broadcasters of analog television encode their signal using different systems. The official systems of transmission were defined by the ITU in 1961 as: A, B, C, D, E, F, G, H, I, K, K1, L, M and N. These systems determine the number of scan lines, frame rate, channel width, video bandwidth, video-audio separation, and so on. A color encoding scheme (NTSC, PAL, or SECAM) could be added to the base monochrome signal. Using RF modulation the signal is then modulated onto a very high frequency (VHF) or ultra high frequency (UHF) carrier wave. Each frame of a television image is composed of scan lines drawn on the screen. The lines are of varying brightness; the whole set of lines is drawn quickly enough that the human eye perceives it as one image. The process repeats and next sequential frame is displayed, allowing the depiction of motion.  The analog television signal contains timing and synchronization information so that the receiver can reconstruct a two-dimensional moving image from a one-dimensional time-varying signal.

The first commercial television systems were black-and-white; the beginning of color television was in the 1950s.

A practical television system needs to take luminance, chrominance (in a color system), synchronization (horizontal and vertical), and audio signals, and broadcast them over a radio transmission. The transmission system must include a means of television channel selection.

Analog broadcast television systems come in a variety of frame rates and resolutions. Further differences exist in the frequency and modulation of the audio carrier. The monochrome combinations still existing in the 1950s were standardized by the International Telecommunication Union (ITU) as capital letters A through N. When color television was introduced, the chrominance information was added to the monochrome signals in a way that black and white televisions ignore. In this way backward compatibility was achieved.

There are three standards for the way the additional color information can be encoded and transmitted. The first was the American NTSC system. The European and Australian PAL and the French and former Soviet Union SECAM standards were developed later and attempt to cure certain defects of the NTSC system. PAL's color encoding is similar to the NTSC systems. SECAM, though, uses a different modulation approach than PAL or NTSC. PAL had a late evolution called PALplus, allowing widescreen broadcasts while remaining fully compatible with existing PAL equipment.

In principle, all three color encoding systems can be used with any scan line/frame rate combination. Therefore, in order to describe a given signal completely, it's necessary to quote the color system plus the broadcast standard as a capital letter. For example, the United States, Canada, Mexico and South Korea use NTSC-M, Japan uses NTSC-J, the UK uses PAL-I, France uses SECAM-L, much of Western Europe and Australia use PAL-B/G, most of Eastern Europe uses SECAM-D/K or PAL-D/K and so on.

Not all of the possible combinations exist. NTSC is only used with system M, even though there were experiments with NTSC-A (405 line) in the UK and NTSC-N (625 line) in part of South America. PAL is used with a variety of 625-line standards (B, G, D, K, I, N) but also with the North American 525-line standard, accordingly named PAL-M.  Likewise, SECAM is used with a variety of 625-line standards.

For this reason, many people refer to any 625/25 type signal as PAL and to any 525/30 signal as NTSC, even when referring to digital signals; for example, on DVD-Video, which does not contain any analog color encoding, and thus no PAL or NTSC signals at all.

Although a number of different broadcast television systems are in use worldwide, the same principles of operation apply.

Displaying an image

A cathode-ray tube (CRT) television displays an image by scanning a beam of electrons across the screen in a pattern of horizontal lines known as a raster. At the end of each line, the beam returns to the start of the next line; at the end of the last line, the beam returns to the beginning of the first line at the top of the screen. As it passes each point, the intensity of the beam is varied, varying the luminance of that point. A color television system is similar except there are three beams that scan together and an additional signal known as chrominance controls the color of the spot.

When analog television was developed, no affordable technology for storing video signals existed; the luminance signal had to be generated and transmitted at the same time at which it is displayed on the CRT.  It was therefore essential to keep the raster scanning in the camera (or other device for producing the signal) in exact synchronization with the scanning in the television.

The physics of the CRT require that a finite time interval be allowed for the spot to move back to the start of the next line (horizontal retrace) or the start of the screen (vertical retrace). The timing of the luminance signal must allow for this.

The human eye has a characteristic called phi phenomenon. Quickly displaying successive scan images creates the illusion of smooth motion. Flickering of the image can be partially solved using a long persistence phosphor coating on the CRT so that successive images fade slowly. However, slow phosphor has the negative side-effect of causing image smearing and blurring when there is rapid on-screen motion occurring.

The maximum frame rate depends on the bandwidth of the electronics and the transmission system, and the number of horizontal scan lines in the image. A frame rate of 25 or 30 hertz is a satisfactory compromise, while the process of interlacing two video fields of the picture per frame is used to build the image. This process doubles the apparent number of video frames per second and further reduces flicker and other defects in transmission.

Receiving signals
The television system for each country will specify a number of television channels within the UHF or VHF frequency ranges. A channel actually consists of two signals: the picture information is transmitted using amplitude modulation on one carrier frequency, and the sound is transmitted with frequency modulation at a frequency at a fixed offset (typically 4.5 to 6 MHz) from the picture signal.

The channel frequencies chosen represent a compromise between allowing enough bandwidth for video (and hence satisfactory picture resolution), and allowing enough channels to be packed into the available frequency band. In practice a technique called vestigial sideband is used to reduce the channel spacing, which would be nearly twice the video bandwidth if pure AM was used.

Signal reception is invariably done via a superheterodyne receiver: the first stage is a tuner which selects a television channel and frequency-shifts it to a fixed intermediate frequency (IF). The signal amplifier performs amplification to the IF stages from the microvolt range to fractions of a volt.

Extracting the sound
At this point the IF signal consists of a video carrier signal at one frequency and the sound carrier at a fixed offset in frequency. A demodulator recovers the video signal. Also at the output of the same demodulator is a new frequency modulated sound carrier at the offset frequency. In some sets made before 1948, this was filtered out, and the sound IF of about 22 MHz was sent to an FM demodulator to recover the basic sound signal. In newer sets, this new carrier at the offset frequency was allowed to remain as intercarrier sound, and it was sent to an FM demodulator to recover the basic sound signal. One particular advantage of intercarrier sound is that when the front panel fine tuning knob is adjusted, the sound carrier frequency does not change with the tuning, but stays at the above-mentioned offset frequency. Consequently, it is easier to tune the picture without losing the sound.

So the FM sound carrier is then demodulated, amplified, and used to drive a loudspeaker. Until the advent of the NICAM and MTS systems, television sound transmissions were monophonic.

Structure of a video signal
The video carrier is demodulated to give a composite video signal containing luminance, chrominance and synchronization signals. The result is identical to the composite video format used by analog video devices such as VCRs or CCTV cameras. To ensure good linearity and thus fidelity, consistent with affordable manufacturing costs of transmitters and receivers, the video carrier is never modulated to the extent that it is shut off altogether. When intercarrier sound was introduced later in 1948, not completely shutting off the carrier had the side effect of allowing intercarrier sound to be economically implemented.

Each line of the displayed image is transmitted using a signal as shown above. The same basic format (with minor differences mainly related to timing and the encoding of color) is used for PAL, NTSC, and SECAM television systems. A monochrome signal is identical to a color one, with the exception that the elements shown in color in the diagram (the colorburst, and the chrominance signal) are not present.

The front porch is a brief (about 1.5 microsecond) period inserted between the end of each transmitted line of picture and the leading edge of the next line's sync pulse. Its purpose was to allow voltage levels to stabilise in older televisions, preventing interference between picture lines. The front porch is the first component of the horizontal blanking interval which also contains the horizontal sync pulse and the back porch.

The back porch is the portion of each scan line between the end (rising edge) of the horizontal sync pulse and the start of active video. It is used to restore the black level (300 mV) reference in analog video. In signal processing terms, it compensates for the fall time and settling time following the sync pulse.

In color television systems such as PAL and NTSC, this period also includes the colorburst signal. In the SECAM system, it contains the reference subcarrier for each consecutive color difference signal in order to set the zero-color reference.

In some professional systems, particularly satellite links between locations, the digital audio is embedded within the line sync pulses of the video signal, to save the cost of renting a second channel. The name for this proprietary system is Sound-in-Syncs.

Monochrome video signal extraction
The luminance component of a composite video signal varies between 0 V and approximately 0.7 V above the black level. In the NTSC system, there is a blanking signal level used during the front porch and back porch, and a black signal level 75 mV above it; in PAL and SECAM these are identical.

In a monochrome receiver, the luminance signal is amplified to drive the control grid in the electron gun of the CRT. This changes the intensity of the electron beam and therefore the brightness of the spot being scanned. Brightness and contrast controls determine the DC shift and amplification, respectively.

Color video signal extraction

U and V signals
A color signal conveys picture information for each of the red, green, and blue components of an image.  However, these are not simply transmitted as three separate signals, because: such a signal would not be compatible with monochrome receivers, an important consideration when color broadcasting was first introduced.  It would also occupy three times the bandwidth of existing television, requiring a decrease in the number of television channels available.

Instead, the RGB signals are converted into YUV form, where the Y signal represents the luminance of the colors in the image. Because the rendering of colors in this way is the goal of both monochrome film and television systems, the Y signal is ideal for transmission as the luminance signal. This ensures a monochrome receiver will display a correct picture in black and white, where a given color is reproduced by a shade of gray that correctly reflects how light or dark the original color is.

The U and V signals are color difference signals. The U signal is the difference between the B signal and the Y signal, also known as B minus Y (B-Y), and the V signal is the difference between the R signal and the Y signal, also known as R minus Y (R-Y). The U signal then represents how purplish-blue or its complementary color, yellowish-green, the color is, and the V signal how purplish-red or it's complementary, greenish-cyan, it is. The advantage of this scheme is that the U and V signals are zero when the picture has no color content.  Since the human eye is more sensitive to detail in luminance than in color, the U and V signals can be transmitted with reduced bandwidth with acceptable results.

In the receiver, a single demodulator can extract an additive combination of U plus V.  An example is the X demodulator used in the X/Z demodulation system. In that same system, a second demodulator, the Z demodulator, also extracts an additive combination of U plus V, but in a different ratio. The X and Z color difference signals are further matrixed into three color difference signals, (R-Y), (B-Y), and (G-Y). The combinations of usually two, but sometimes three demodulators were:

In the end, further matrixing of the above color-difference signals c through f yielded the three color-difference signals, (R-Y), (B-Y), and (G-Y).

The R, G, and B signals in the receiver needed for the display device (CRT, Plasma display, or LCD display) are electronically derived by matrixing as follows: R is the additive combination of (R-Y) with Y, G is the additive combination of (G-Y) with Y, and B is the additive combination of (B-Y) with Y. All of this is accomplished electronically. It can be seen that in the combining process, the low-resolution portion of the Y signals cancel out, leaving R, G, and B signals able to render a low-resolution image in full color. However, the higher resolution portions of the Y signals do not cancel out, and so are equally present in R, G, and B, producing the higher-resolution image detail in monochrome, although it appears to the human eye as a full-color and full-resolution picture.

NTSC and PAL systems

In the NTSC and PAL color systems, U and V are transmitted by using quadrature amplitude modulation of a subcarrier. This kind of modulation applies two independent signals to one subcarrier, with the idea that both signals will be recovered independently at the receiving end. For NTSC, the subcarrier is at 3.58 MHz. For the PAL system it is at 4.43 MHz. The subcarrier itself is not included in the modulated signal (suppressed carrier), it is the subcarrier sidebands that carry the U and V information. The usual reason for using suppressed carrier is that it saves on transmitter power. In this application a more important advantage is that the color signal disappears entirely in black and white scenes. The subcarrier is within the bandwidth of the main luminance signal and consequently can cause undesirable artifacts on the picture, all the more noticeable in black and white receivers.

A small sample of the subcarrier, the colorburst, is included in the horizontal blanking portion, which is not visible on the screen. This is necessary to give the receiver a phase reference for the modulated signal.  Under quadrature amplitude modulation the modulated chrominance signal changes phase as compared to its subcarrier and also changes amplitude. The chrominance amplitude (when considered together with the Y signal) represents the approximate saturation of a color, and the chrominance phase against the subcarrier reference approximately represents the hue of the color. For particular test colors found in the test color bar pattern, exact amplitudes and phases are sometimes defined for test and troubleshooting purposes only.

Due to the nature of the quadrature amplitude modulation process that created the chrominance signal, at certain times, the signal represents only the U signal, and 70 nanoseconds (NTSC) later, it represents only the V signal. About 70 nanoseconds later still, -U, and another 70 nanoseconds, -V.  So to extract U, a synchronous demodulator is utilized, which uses the subcarrier to briefly gate the chroma every 280 nanoseconds, so that the output is only a train of discrete pulses, each having an amplitude that is the same as the original U signal at the corresponding time. In effect, these pulses are discrete-time analog samples of the U signal. The pulses are then low-pass filtered so that the original analog continuous-time U signal is recovered. For V, a 90-degree shifted subcarrier briefly gates the chroma signal every 280 nanoseconds, and the rest of the process is identical to that used for the U signal.

Gating at any other time than those times mentioned above will yield an additive mixture of any two of U, V, -U, or -V. One of these off-axis (that is, of the U and V axis) gating methods is called I/Q demodulation.  Another much more popular off-axis scheme was the X/Z demodulation system. Further matrixing recovered the original U and V signals. This scheme was actually the most popular demodulator scheme throughout the 1960s.

The above process uses the subcarrier. But as previously mentioned, it was deleted before transmission, and only the chroma is transmitted. Therefore, the receiver must reconstitute the subcarrier. For this purpose, a short burst of the subcarrier, known as the colorburst, is transmitted during the back porch (re-trace blanking period) of each scan line. A subcarrier oscillator in the receiver locks onto this signal (see phase-locked loop) to achieve a phase reference, resulting in the oscillator producing the reconstituted subcarrier.

NTSC uses this process unmodified.  Unfortunately, this often results in poor color reproduction due to phase errors in the received signal, caused sometimes by multipath, but mostly by poor implementation at the studio end.  With the advent of solid-state receivers, cable TV, and digital studio equipment for conversion to an over-the-air analog signal, these NTSC problems have been largely fixed, leaving operator error at the studio end as the sole color rendition weakness of the NTSC system. In any case, the PAL D (delay) system mostly corrects these kinds of errors by reversing the phase of the signal on each successive line, and averaging the results over pairs of lines. This process is achieved by the use of a 1H (where H = horizontal scan frequency) duration delay line. Phase shift errors between successive lines are therefore canceled out and the wanted signal amplitude is increased when the two in-phase (coincident) signals are re-combined.

NTSC is more spectrum efficient than PAL, giving more picture detail for a given bandwidth.  This is because sophisticated comb filters in receivers are more effective with NTSC's 4 color frame sequence compared to PAL's 8-field sequence.  However, in the end, the larger channel width of most PAL systems in Europe still gives PAL systems the edge in transmitting more picture detail.

SECAM system
In the SECAM television system, U and V are transmitted on alternate lines, using simple frequency modulation of two different color subcarriers.

In some analog color CRT displays, starting in 1956, the brightness control signal (luminance) is fed to the cathode connections of the electron guns, and the color difference signals (chrominance signals) are fed to the control grids connections.  This simple CRT matrix mixing technique was replaced in later solid state designs of signal processing with the original matrixing method used in the 1954 and 1955 color TV receivers.

Synchronization
Synchronizing pulses added to the video signal at the end of every scan line and video frame ensure that the sweep oscillators in the receiver remain locked in step with the transmitted signal so that the image can be reconstructed on the receiver screen.

A sync separator circuit detects the sync voltage levels and sorts the pulses into horizontal and vertical sync.

Horizontal synchronization
The horizontal sync pulse, separates the scan lines. The horizontal sync signal is a single short pulse that indicates the start of every line. The rest of the scan line follows, with the signal ranging from 0.3 V (black) to 1 V (white), until the next horizontal or vertical synchronization pulse.

The format of the horizontal sync pulse varies. In the 525-line NTSC system it is a 4.85 μs pulse at 0 V. In the 625-line PAL system the pulse is 4.7 μs at 0 V.  This is lower than the amplitude of any video signal (blacker than black) so it can be detected by the level-sensitive sync separator circuit of the receiver.

Two-timing intervals are defined – the front porch between the end of the displayed video and the start of the sync pulse, and the back porch after the sync pulse and before the displayed video. These and the sync pulse itself are called the horizontal blanking (or retrace) interval and represent the time that the electron beam in the CRT is returning to the start of the next display line.

Vertical synchronization

Vertical synchronization separates the video fields. In PAL and NTSC, the vertical sync pulse occurs within the vertical blanking interval. The vertical sync pulses are made by prolonging the length of horizontal sync pulses through almost the entire length of the scan line.

The vertical sync signal is a series of much longer pulses, indicating the start of a new field. The sync pulses occupy the whole line interval of a number of lines at the beginning and end of a scan; no picture information is transmitted during vertical retrace. The pulse sequence is designed to allow horizontal sync to continue during vertical retrace; it also indicates whether each field represents even or odd lines in interlaced systems (depending on whether it begins at the start of a horizontal line, or midway through).

The format of such a signal in 525-line NTSC is:
 pre-equalizing pulses (6 to start scanning odd lines, 5 to start scanning even lines)
 long-sync pulses (5 pulses)
 post-equalizing pulses (5 to start scanning odd lines, 4 to start scanning even lines)

Each pre- or post-equalizing pulse consists of half a scan line of black signal: 2 μs at 0 V, followed by 30 μs at 0.3 V. Each long sync pulse consists of an equalizing pulse with timings inverted: 30 μs at 0  V, followed by 2 μs at 0.3  V.

In video production and computer graphics, changes to the image are often performed during the vertical blanking interval to avoid visible discontinuity of the image. If this image in the framebuffer is updated with a new image while the display is being refreshed, the display shows a mishmash of both frames, producing page tearing partway down the image.

Horizontal and vertical hold
The sweep (or deflection) oscillators were designed to run without a signal from the television station (or VCR, computer, or other composite video source). This allows the television receiver to display a raster and to allow an image to be presented during antenna placement. With sufficient signal strength, the receiver's sync separator circuit would split timebase pulses from the incoming video and use them to reset the horizontal and vertical oscillators at the appropriate time to synchronize with the signal from the station.

The free-running oscillation of the horizontal circuit is especially critical, as the horizontal deflection circuits typically power the flyback transformer (which provides acceleration potential for the CRT) as well as the filaments for the high voltage rectifier tube and sometimes the filament(s) of the CRT itself. Without the operation of the horizontal oscillator and output stages in these television receivers, there would be no illumination of the CRT's face.

The lack of precision timing components in early equipment meant that the timebase circuits occasionally needed manual adjustment. If their free-run frequencies were too far from the actual line and field rates, the circuits would not be able to follow the incoming sync signals. Loss of horizontal synchronization usually resulted in an unwatchable picture; loss of vertical synchronization would produce an image rolling up or down the screen.

Older analog television receivers often provide manual controls to adjust horizontal and vertical timing. The adjustment takes the form of horizontal hold and vertical hold controls, usually on the front panel along with other common controls. These adjust the free-run frequencies of the corresponding timebase oscillators.

A slowly rolling vertical picture demonstrates that the vertical oscillator is nearly synchronized with the television station but is not locking to it, often due to a weak signal or a failure in the sync separator stage not resetting the oscillator.

Horizontal sync errors cause the image to be torn diagonally and repeated across the screen as if it were wrapped around a screw or a barber's pole; the greater the error, the more copies of the image will be seen at once wrapped around the barber pole.

By the early 1980s the efficacy of the synchronization circuits, plus the inherent stability of the sets' oscillators, had been improved to the point where these controls were no longer necessary.  Integrated Circuits which eliminated the horizontal hold control were starting to appear as early as 1969.

The final generations of analog television receivers used IC-based designs where the receiver's timebases were derived from accurate crystal oscillators. With these sets, adjustment of the free-running frequency of either sweep oscillator was unnecessary and unavailable.

Horizontal and vertical hold controls were rarely used in CRT-based computer monitors, as the quality and consistency of components were quite high by the advent of the computer age, but might be found on some composite monitors used with the 1970s–80s home or personal computers.

Other technical information

Components of a television system

The tuner is the object which, with the aid of an antenna, isolates the television signals received over the air. There are two types of tuners in analog television, VHF and UHF tuners. The VHF tuner selects the VHF television frequency. This consists of a 4 MHz video bandwidth and a 2 MHz audio bandwidth. It then amplifies the signal and converts it to a 45.75 MHz Intermediate Frequency (IF) amplitude-modulated video and a 41.25 MHz IF frequency-modulated audio carrier.

The IF amplifiers are centered at 44 MHz for optimal frequency transference of the audio and video carriers. Like radio, television has automatic gain control (AGC). This controls the gain of the IF amplifier stages and the tuner.

The video amp and output amplifier is implemented using a pentode or a power transistor. The filter and demodulator separates the 45.75 MHz video from the 41.25 MHz audio then it simply uses a diode to detect the video signal. After the video detector, the video is amplified and sent to the sync separator and then to the picture tube.

The audio signal goes to a 4.5 MHz amplifier. This amplifier prepares the signal for the 4.5Mhz detector. It then goes through a 4.5 MHz IF transformer to the detector. In television, there are 2 ways of detecting FM signals. One way is by the ratio detector. This is simple but very hard to align. The next is a relatively simple detector. This is the quadrature detector. It was invented in 1954. The first tube designed for this purpose was the 6BN6 type. It is easy to align and simple in circuitry. It was such a good design that it is still being used today in the Integrated circuit form. After the detector, it goes to the audio amplifier.

The next part is the sync separator and clipper. From the detected video signal, this circuit extracts and conditions signals that the horizontal and vertical oscillators can use to keep in sync with the video. It also forms the AGC voltage, as previously stated.

The horizontal and vertical oscillators form the raster on the CRT. They are driven by the sync separator. There are many ways to create these oscillators. The earliest is the thyratron oscillator. Although it is known to drift, it makes a perfect sawtooth wave. This sawtooth wave is so good that no linearity control is needed. This oscillator was designed for the electrostatic deflection CRTs but also found some use in electromagnetically deflected CRTs. The next oscillator developed was the blocking oscillator which uses a transformer to create a sawtooth wave. This was only used for a brief time period and never was very popular. Finally the multivibrator was probably the most successful. It needed more adjustment than the other oscillators, but it is very simple and effective. This oscillator was so popular that it was used from the early 1950s until today.

Two oscillator amplifiers are neede. The vertical amplifier directly drives the yoke. Since it operates at 50 or 60 Hz and drives an electromagnet, it is similar to an audio amplifier. Because of the rapid deflection required, the horizontal oscillator requires a high-power flyback transformer driven by a high-powered tube or transistor. Additional windings on this flyback transformer typically power other parts of the system.

Sync separator

Image synchronization is achieved by transmitting negative-going pulses. The horizontal sync signal is a single short pulse that indicates the start of every line. Two-timing intervals are defined – the front porch between the end of the displayed video and the start of the sync pulse, and the back porch after the sync pulse and before the displayed video. These and the sync pulse itself are called the horizontal blanking (or retrace) interval and represent the time that the electron beam in the CRT is returning to the start of the next display line.

The vertical sync signal is a series of much longer pulses, indicating the start of a new field. The vertical sync pulses occupy the whole of line interval of a number of lines at the beginning and end of a scan; no picture information is transmitted during vertical retrace. The pulse sequence is designed to allow horizontal sync to continue during vertical retrace.

In the television receiver, a sync separator circuit detects the sync voltage levels and sorts the pulses into horizontal and vertical sync.

Loss of horizontal synchronization usually resulted in an unwatchable picture; loss of vertical synchronization would produce an image rolling up or down the screen.

Counting sync pulses, a video line selector picks a selected line from a TV signal, used for teletext, on-screen displays, station identification logos as well as in the industry when cameras were used as a sensor.

Timebase circuits

In an analog receiver with a CRT display sync pulses are fed to horizontal and vertical timebase circuits (commonly called "sweep circuits" in the United States), each consisting of an oscillator and an amplifier.  These generate modified sawtooth and parabola current waveforms to scan the electron beam in a linear way.  The waveform shapes are necessary to make up for the distance variations from the electron beam source and the screen surface.  The oscillators are designed to free-run at frequencies very close to the field and line rates, but the sync pulses cause them to reset at the beginning of each scan line or field, resulting in the necessary synchronization of the beam sweep with the originating signal. The output waveforms from the timebase amplifiers are fed to the horizontal and vertical deflection coils wrapped around the CRT tube. These coils produce magnetic fields proportional to the changing current, and these deflect the electron beam across the screen.

In the 1950s, the power for these circuits was derived directly from the mains supply. A simple circuit consisted of a series voltage dropper resistance and a rectifier valve (tube) or semiconductor diode. This avoided the cost of a large high voltage mains supply (50 or 60 Hz) transformer. This type of circuit was used for the thermionic valve (vacuum tube) technology. It was inefficient and produced a lot of heat which led to premature failures in the circuitry. Although failure was common, it was easily repairable.

In the 1960s, semiconductor technology was introduced into timebase circuits.  During the late 1960s in the UK, synchronous (with the scan line rate) power generation was introduced into solid state receiver designs. These had very complex circuits in which faults were difficult to trace, but had very efficient use of power.

In the early 1970s AC mains (50 or 60 Hz), and line timebase (15,625 Hz), thyristor based switching circuits were introduced. In the UK use of the simple (50  Hz) types of power, circuits were discontinued. The reason for design changes arose from the electricity supply contamination problems arising from EMI, and supply loading issues due to energy being taken from only the positive half cycle of the mains supply waveform.

CRT flyback power supply

Most of the receiver's circuitry (at least in transistor- or IC-based designs) operates from a comparatively low-voltage DC power supply.  However, the anode connection for a cathode-ray tube requires a very high voltage (typically 10–30 kV) for correct operation.

This voltage is not directly produced by the main power supply circuitry; instead, the receiver makes use of the circuitry used for horizontal scanning. Direct current (DC), is switched through the line output transformer, and alternating current (AC) is induced into the scan coils. At the end of each horizontal scan line the magnetic field, which has built up in both transformer and scan coils by the current, is a source of latent electromagnetic energy. This stored collapsing magnetic field energy can be captured. The reverse flow, short duration, (about 10% of the line scan time) current from both the line output transformer and the horizontal scan coil is discharged again into the primary winding of the flyback transformer by the use of a rectifier which blocks this negative reverse emf. A small value capacitor is connected across the scan switching device. This tunes the circuit inductances to resonate at a much higher frequency. This slows down (lengthens) the flyback time from the extremely rapid decay rate that would result if they were electrically isolated during this short period. One of the secondary windings on the flyback transformer then feeds this brief high-voltage pulse to a Cockcroft–Walton generator design voltage multiplier. This produces the required EHT supply. A flyback converter is a power supply circuit operating on similar principles.

A typical modern design incorporates the flyback transformer and rectifier circuitry into a single unit with a captive output lead, (known as a diode split line output transformer or an Integrated High Voltage Transformer (IHVT)), so that all high-voltage parts are enclosed. Earlier designs used a separate line output transformer and a well-insulated high voltage multiplier unit. The high frequency (15 kHz or so) of the horizontal scanning allows reasonably small components to be used.

Transition to digital

In many countries, over-the-air broadcast television of analog audio and analog video signals has been discontinued, to allow the re-use of the television broadcast radio spectrum for other services such as datacasting and subchannels.

The first country to make a wholesale switch to digital over-the-air (terrestrial television) broadcasting was Luxembourg in 2006, followed later in 2006 by the Netherlands; in 2007 by Finland, Andorra, Sweden and Switzerland; in 2008 by Belgium (Flanders) and Germany; in 2009 by the United States (high power stations), southern Canada, the Isle of Man, Norway, and Denmark. In 2010, Belgium (Wallonia), Spain, Wales, Latvia, Estonia, the Channel Islands, San Marino, Croatia, and Slovenia; in 2011 Israel, Austria, Monaco, Cyprus, Japan (excluding Miyagi, Iwate, and Fukushima prefectures), Malta and France; in 2012 the Czech Republic, Arab World, Taiwan, Portugal, Japan (including Miyagi, Iwate, and Fukushima prefectures), Serbia, Italy, Canada, Mauritius, the United Kingdom, the Republic of Ireland, Lithuania, Slovakia, Gibraltar, and South Korea; in 2013, the Republic of Macedonia, Poland, Bulgaria, Hungary, Australia, and New Zealand, completed the transition. The United Kingdom made the transition to digital television between 2008 and 2012, with the exception of Whitehaven, which made the switch over in 2007. The first digital TV-only area in the United Kingdom was Ferryside in Carmarthenshire.

The Digital television transition in the United States for high-powered transmission was completed on 12 June 2009, the date that the Federal Communications Commission (FCC) set. Almost two million households could no longer watch television because they had not prepared for the transition. The switchover had been delayed by the DTV Delay Act. While the majority of the viewers of over-the-air broadcast television in the U.S. watch full-power stations (which number about 1800), there are three other categories of television stations in the U.S.: low-power broadcasting stations, class A stations, and television translator stations. They were given later deadlines. In broadcasting, the United States influences southern Canada and northern Mexico because those areas are covered by television stations in the U.S.

In Japan, the switch to digital began in northeastern Ishikawa Prefecture on 24 July 2010 and ended in 43 of the country's 47 prefectures (including the rest of Ishikawa) on 24 July 2011, but in Fukushima, Iwate, and Miyagi prefectures, the conversion was delayed to 31 March 2012, due to complications from the 2011 Tōhoku earthquake and tsunami and its related nuclear accidents.

In Canada, most of the larger cities turned off analog broadcasts on 31 August 2011.

China had scheduled to end analog broadcasting between 2015 and 2018.

Brazil switched to digital television on 2 December 2007 in its major cities. It is estimated that Brazil will end analog broadcasting in 2023.

In Malaysia, the Malaysian Communications & Multimedia Commission (MCMC) advertised for tender bids to be submitted in the third quarter of 2009 for the 470 through 742  MHz UHF allocation, to enable Malaysia's broadcast system to move into DTV.  The new broadcast band allocation would result in Malaysia's having to build an infrastructure for all broadcasters, using a single digital terrestrial transmission/television broadcast (DTTB) channel. Large portions of Malaysia are covered by television broadcasts from Singapore, Thailand, Brunei, and Indonesia (from Borneo and Batam). Starting from 1 November 2019, all regions in Malaysia were no longer using the analog system after the states of Sabah and Sarawak finally turned it off on 31 October 2019.

In Singapore, digital television under DVB-T2 began on 16 December 2013. The switchover was delayed many times until analog TV was switched off at midnight on 2 January 2019.

In the Philippines, the National Telecommunications Commission required all broadcasting companies to end analog broadcasting on 31 December 2015 at 11:59 p.m. Due to delay of the release of the implementing rules and regulations for digital television broadcast, the target date was moved to 2020. Full digital broadcast is expected in 2021 and all of the analog TV services should be shut down by the end of 2023.

In the Russian Federation, the Russian Television and Radio Broadcasting Network (RTRS) disabled analog broadcasting of federal channels in five stages, shutting down broadcasting in multiple federal subjects at each stage. The first region to have analog broadcasting disabled was Tver Oblast on 3 December 2018, and the switchover was completed on 14 October 2019.  During the transition, DVB-T2 receivers and monetary compensations for purchasing of terrestrial or satellite digital TV reception equipment were provided to disabled people, World War II veterans, certain categories of retirees and households with income per member below living wage.

See also

 Amateur television
 Narrow-bandwidth television
 Overscan
 Slow-scan television
 Terrestrial television
 Television transmitter
 Vertical blanking interval
 Field (video)
 Video frame
 Glossary of video terms

Notes

References

External links

 Video signal measurement and generation
 Television synchronisation
 Video broadcast standard frequencies and country listings
 EDN magazine describing design of a 1958 transistorised television receiver
 Designing the color television signal in the early 1950s as described by two engineers working directly with the NTSC

Television technology
Television terminology

Analog television


John Anthony Helliwell (born 15 February 1945) is an English musician, best known as the saxophonist, secondary keyboardist, and backing vocalist for the rock band Supertramp. He also served as an MC during the band's concerts, talking and making jokes to the audience between songs.

Helliwell played with The Alan Bown Set, replacing Dave Green when he joined in January 1966, before joining Supertramp in 1973 along with bassist Dougie Thomson, who convinced Helliwell to make the move. In 2004, Helliwell formed the band Crème Anglaise with Mark Hart, who had joined Supertramp in 1985. This group recorded their eponymous debut album in 2005.

In 1987 Helliwell played on Pink Floyd's album A Momentary Lapse of Reason; his name was misspelled as "Halliwell". This was after Pink Floyd guitarist David Gilmour had played on Supertramp's album Brother Where You Bound. Helliwell also played on French singer Jean-Jacques Goldman's 1985 album Positif, and clarinet on Sara Hickman's 1990 album Shortstop.

During a professional lull in the 1990s, Helliwell began studying for a music degree at the Royal Northern College of Music in Manchester, but he discontinued his studies to join Supertramp on tour when Some Things Never Change was released. In 2004 he contributed saxophone work on the Simon Apple album River to the Sea.

Helliwell contributed clarinet to The Pineapple Thief's song "Fend For Yourself" from their Your Wilderness album which was released in 2016.

Helliwell fronts the Super Big Tramp Band, which has a jazz big band line-up of trumpets, trombones, saxophones and rhythm section. It plays versions of Supertramp tunes, arranged by members of the band, with no vocals, but with Helliwell as the chief soloist. The band first played in Manchester in June 2013. In 2019 the band played at the Manchester Jazz Festival in May and was scheduled to play in Hull and Hamburg later in the year.

In October 2020, Helliwell released Ever Open Door, a CD album of ballads with Helliwell on saxophone and clarinet, with a string quartet and Hammond organ.

References

External links
 Helliwell's personal website
 John Helliwell biography

English keyboardists
English rock saxophonists
British male saxophonists
Melodica players
Supertramp members
1945 births
Living people
British expatriates in the United States
People from Todmorden
People from Topanga, California
21st-century saxophonists
21st-century British male musicians
The Alan Bown Set members

John Helliwell


Al-Ahsa, sometimes Al-Hasa, El Hasa, or Hadjar is a traditional oasis region in eastern Saudi Arabia. The oasis is about 60 km inland from the Persian Gulf.

Al-Ahsa is part of the region known historically as Al-Bahrayn.  It includes the eastern coast of the Arabian Peninsula down to the borders of Oman.  It also includes the island of Awal (modern-day Bahrain).

Al-Hasa has one of the largest numbers of Shia Muslims in mostly Sunni Saudi Arabia.

With an area of around , Al-Ahsa Oasis is the largest oasis in the world. There are more than 2.5 million palm trees including date palms in the oasis, which is fed from a huge underground aquifer and irrigated by the flow of more than 280 artesian springs, which allows agriculture all year round in a region that is otherwise sand desert.

Main cities and villages
 Al Hofuf: capital city and has lots of traditional markets.
 Al Mubarraz: large city with many big markets.
 Al-Omran: has more than 15 villages and well known for the many farms.
 Shaybah: oil town in the Empty Quarter.
 More than 50 Villages.

References

History of the Middle East
Geography of Saudi Arabia

Al-Ahsa Oasis


Winchester College is a well-known boys' school. It is an example of a British public school. The school is located in the city of Winchester in Hampshire, England. Its official name is Collegium Sanctae Mariae prope Wintoniam (or Collegium Beatae Mariae Wintoniensis prope Winton), or St Mary's College near Winchester. The school is commonly just called "Winchester". Winchester has existed for over six hundred years. It has the longest unbroken history of any school in England. It is the oldest of the original nine English public schools as defined by the Public Schools Act 1868. 37% of students go to Cambridge or Oxford.

History
Winchester College was founded in 1382 by William of Wykeham, Bishop of Winchester and Chancellor to Richard II. The first seventy students entered the school in 1394. It was founded with New College, Oxford. Winchester was built to get students ready to attend New College. This was the model for Eton College and King's College, Cambridge 50 years later and for Westminster School, Christ Church, Oxford and Trinity College, Cambridge in Tudor times.

The headmaster is currently Dr Timothy Hands, formerly of Magdalen College School

Other websites
 Winchester College website
 http://www.astoft.co.uk/winchestercollege Pages on the architecture of the college

References

Schools in England
Winchester
1382 establishments
Organisations based in Hampshire

Winchester College


Taizu Emperor (, 1559 - 1626) was the founding father of the Qing Dynasty. His name was Nurhaci and Aisin Gioro was his surname. The reign name was Tian Ming. Nurhaci was Manchurian. He was also the creator of the Manchu alphabet.

Life
In 1580, Nurhaci became the Jianzhou general of the Ming Dynasty. He unified the Manchu tribe and organised the Eight Banners.

In 1616, Nurhaci declared himself Khan (King) and founded the Jin Dynasty in Liaoning.

In 1618, in order to encourage people to against the Ming Dynasty. Nurhaci wrote an article called the Seven Great Vexations and sent it to the public.

Form 1618 until 1622, Nurhaci led armies to against the Ming Dynasty. He successfully occupied 70 cities in the north-eastern part of China. The capital was changed to Liao Yang after several battles.

In 1622, Nurhaci's armies captured Guangning.

In 1626, Nurhaci led armies to attack the Ningyuan city. Unluckily, Nurhaci was wounded by Yuan Chonghuan's Portuguese cannon and he died 2 days later at a little town called De-A Man.

Emperors of Qing Dynasty
1559 births
1626 deaths
17th century in China

Nurhaci


Parasitoids are parasites whose larvae develop inside another organism's body. This usually results in the death of the host, which sets them apart from 'traditional' parasites. There are twelve superfamilies of parasitic wasps which are entirely or mainly parasitoid. The largest family are the ichneumons, with over 80,000 species.

In parasitoids the adult stage is free-living: it finds the 'host' for the next generation. The female parasitoid places the eggs, on or in the body of a host. The host is food for their growth.
Normal parasites use vectors as the way of getting to other hosts.

In Hymenoptera there are many variations. The distinction between the 'parasitic' and the 'traditional' hymenoptera can run very thin.
In Britain there are about 6500 species of Hymenoptera  more than in any other insect order  and just one parasitoid superfamily, the Ichneumonoidea, has nearly half of them. Most workers now recognise only two families in Ichneumonoidea. These are Ichneumonidae, with over two thousand British species, and Braconidae, with nearly 1200 representatives in Britain. They are, respectively, the largest and the second largest families of British insects. Only a beetle family, the Staphylinidae, is near the thousand mark. Ichneumonoids also include the largest parasitoids.

Hymenopteran parasitoids often have unique life cycles. In one family, the Trigonalidae, the female wasps deposit eggs into small pockets they cut into the edge of leaves with their ovipositor. A caterpillar chewing these leaves may swallow some of the eggs. When they get into the caterpillar's gut, they hatch and burrow through the gut wall and into the body cavity. Later they search the caterpillar's body cavity for other parasitoid larvae, and it is these they attack and feed on. Some trigonalids, once they are in a caterpillar or sawfly larva, need their host to fall prey to a social wasp. The wasp carries the caterpillar back to its nest, and there it is butchered and fed to the wasp's young. The young serve as host for the trigonalid, the eggs of which are in the butchered caterpillar.

Related pages

 Botfly

References

Parasitoid


Michael Chance CBE (born in Buckinghamshire, United Kingdom 7 March 1955) is an English countertenor and the founder and Artistic Director of The Grange Festival.

Chance was born in Penn, Buckinghamshire, into a musical family. After growing up as a chorister at St George's Chapel, Windsor Castle, attending the St George's School, he went on to Eton and later King's College, Cambridge.

His first operatic appearance was in the Buxton Festival in Ronald Eyre's staging of Cavalli's Giasone which was followed by appearances in Lyon, Cologne, and three seasons with Kent Opera. Subsequently, he has performed in the Sydney Opera House, Teatro Colon in Buenos Aires, La Scala Milan, Florence, New York, Lisbon, Oviedo, Leipzig, Paris, Brussels, Amsterdam and with Covent Garden, Glyndebourne, and English National Opera.

His roles include the title roles of Orfeo (Gluck), Giasone, Giustino, Rinaldo and Ascanio in Alba, Solomon, Ottone / L'incoronazione di Poppea, Athamas / Semele, Andronico / Tamerlano, Oberon / A Midsummer Night's Dream, Tolomeo / Giulio Cesare and Apollo / Death in Venice. He has had roles written specially for him by Sir Harrison Birtwistle (Orpheus / The Second Mrs Kong) and Judith Weir (A Military Governor / A night at the Chinese Opera). Recent festival appearances include Edinburgh, Aix-en-Provence, BBC Proms in London, Salzburg and Bertarido in a new production of Handel's Rodelinda for the Bayerische Staatsoper in Munich.

His appearances in oratorio and recital have taken him to concert halls all over the world including Carnegie Hall, Concertgebouw, Musikverein, Neue Gewandhaus and Berlin's Philharmonie. He has given recitals in Frankfurt, Vienna, Amsterdam, Israel, New York and London's Wigmore Hall with a variety of programmes, ranging from Elizabethan lute songs to new works commissioned for him. He sings regularly with the viol consort Fretwork and has toured with them to Japan and the United States.

Michael Chance's list of recordings is numerous and widespread. He received a Grammy award for his participation in Handel's Semele for Deutsche Grammophon with John Nelson and Kathleen Battle. He has recorded frequently with John Eliot Gardiner, including the Bach Passions and Cantatas, B Minor Mass, Monteverdi's Orfeo and L'Incoronazione di Poppea and Handel's Jephtha, Tamerlano and Agrippina. Other conductors he has recorded with include Trevor Pinnock, Frans Brüggen, Ton Koopman and Nicholas McGegan. On his CD for Deutsche Grammophon, "Michael Chance, the Art of Counter-tenor", he sings solo alto cantatas by Vivaldi with Trevor Pinnock and the English Concert.

He took part in the project of Ton Koopman and the Amsterdam Baroque Orchestra & Choir to record the complete vocal works of Johann Sebastian Bach.

His belief in extending the counter-tenor repertoire has prompted new work to be composed for him by Richard Rodney Bennett, Alexander Goehr, Tan Dun, Anthony Powers, John Tavener, and Elvis Costello - amongst others.

His television appearances include A Night at the Chinese Opera, Death in Venice, The Fairy Queen, the three Monteverdi operas with Netherlands Opera, Poppea with Welsh National Opera, Messiah in Dublin with Sir Neville Marriner, and in the Autumn 1999 he was featured by the South Bank Show.
He was appointed Commander of the Order of the British Empire (CBE) in the 2009 New Year Honours.

It was announced in October 2015 that Michael Chance would become the first Artistic Director of The Grange Festival, a new opera company established to continue performances at The Grange theatre in Hampshire. Opening in June 2017 with operas by Monteverdi, Mozart, Bizet and Britten, The Grange Festival is one of the few opera companies in the world to be led by an internationally renowned opera singer.

Footnotes

External links
Official website
The Grange Festival website
Bach-Cantatas.com: Michael Chance
Hyperion Records: Michael Chance
Michael Chance: Affinities between baroque and rock voices - Opera~Opera article

Official website biography

Operatic countertenors
British performers of early music
1955 births
People from Chiltern District
Living people
People educated at Eton College
Alumni of King's College, Cambridge
Grammy Award winners
Commanders of the Order of the British Empire
People educated at St George's School, Windsor Castle
Choral Scholars of the Choir of King's College, Cambridge

Michael Chance


Albert Charles Paul Marie Roussel (5 April 1869 - 23 August 1937) was a French composer. Roussel spent seven years as a midshipman. He only turned to music as an adult. But he then became one of the most important composers of the years between the two world wars. His earlier music came from the impressionism of Debussy and Ravel. He turned more towards neoclassicism with his later music.

Personal life

Albert Roussel was born in Tourcoing (Nord department of France). HIs earliest interest was not music. It was mathematics. He spent some time in the French Navy. In 1889 and 1890 he served on the crew of the frigate Iphigénie. These travels were significant to his later career as a composer. This is because many of his musical works would reflect his interest in far-off and interesting places.

After Roussel left the Navy in 1894, he began to study music with Eugène Gigout. He continued his studies until 1908 at the Schola Cantorum (one of his teachers there was Vincent d'Indy). While he studied, he would also teach at the Schola. His fellow students were Erik Satie and the young Edgard Varèse.

During World War I, he served as an ambulance driver on the Western Front. After the war, he bought a summer house in Normandy. This is where he gave most of his time to composing music.

Roussel was a classicist. Some of his first works are very much like impressionism. But he soon found a style fit just for him. This style had a strong rhythmic sound.

The Schola Cantorum left a mark on Roussel's mature writing. Compared with the style of other French composers like Gabriel Fauré or Claude Debussy, Roussel's orchestration is rather powerful and heavy.

Roussel also liked jazz. He wrote a piano-vocal composition called Jazz dans la nuit. This has a lot in common with other jazz-influenced works such as the "Blues" second movement of Maurice Ravel's Violin Sonata.

Roussel's most important pieces include his ballets. They are Le festin de l'araignée, Bacchus et Ariane, and Aeneas. Among his other works are four symphonies (the Third is the most often played), a piano concerto, a concertino for cello and orchestra, a psalm setting for chorus and orchestra, music for the theater, solo piano music, and songs. He died in the town of Royan in western France in 1937. That is the same year that his countrymen Ravel, Charles-Marie Widor, and Gabriel Pierné died.

Arturo Toscanini included the suite from the ballet Le festin de l'araignée in one of his concerts with the NBC Symphony Orchestra. Georges Prêtre recorded this same music with the Orchestre National de France for EMI in 1984.

Works

Stage
 Le marchand de sable qui passe, incidental music for a play, Le Havre, 16 December 1908, Op. 13
 Le festin de l'araignée, ballet in one act. f.p. 3 April 1913, Op. 17
 Padmâvatî, opera in 2 acts (1913–18, Louis Laloy, after T.-M. Pavie). f.p. Paris Opéra, 1 June 1923, Op. 18
 La naissance de la lyre, opera in 1 act, Paris Opéra, 1 July 1925, Op. 24
 Sarabande (1927; for the children's ballet L'éventail de Jeanne, to which ten French composers each contributed a dance)
 Bacchus and Ariadne, ballet in two acts. f.p. Paris Opéra, 22 May 1931, Op. 43
 Le testament de la tante Caroline, opera in 3 acts, 14 November 1936
 Aeneas, ballet, Op. 54
 Prelude to Act 2 of Le quatorze juillet by Romain Rolland, Paris, 14 July 1936
 Elpénor, radio score, 1947, Op. 59

Orchestral
 Evocations pour orchestra Op. 15
 Sinfonietta for String Orchestra, Op. 52
 Suite for Orchestra in F major, Op. 33
 Symphony No. 1 in D minor The Poem of the Forest, Op. 7
 Symphony No. 2 in B-flat major, Op. 23
 Symphony No. 3 in G minor, Op. 42
 Symphony No. 4 in A major, Op. 53

Concertante
 Cello Concertino, Op. 57
 Piano Concerto in G major, Op. 36

Vocal/Choral
 Psalm 80 for tenor, choir, and orchestra, Op. 37

Chamber/Instrumental
 Andante and Scherzo, for flute and piano, Op. 51
 Elpenor for flute and string quartet, Op. 59
 Divertissement for piano and wind quintet, Op. 6
 Joueurs de Flûte, flute and piano, Op. 27
 Piano Trio in E-flat, Op. 2
 Serenade for flute, string trio, and harp, Op. 30
 Sonatine for Piano, Op. 16
 String Quartet, Op. 45
 String Trio, Op. 58
 Suite for Piano in F-sharp minor, Op. 14
 Trio for Flute, Viola, and Cello, Op. 40
 Violin Sonata No. 1 in D minor, Op. 11
 Violin Sonata No. 2 in A major, Op. 28
 Segovia, for guitar, Op. 29
 Impromptu for harp

Recordings
 Symphony No. 3 and Ariadne et Bacchus - Royal Scottish National Orchestra/Stephane Deneve (Naxos Records)
 Symphony No. 3 - New York Philharmonic/Leonard Bernstein (Sony Classical)
 Symphony No. 4 - Philharmonia Orchestra/Herbert von Karajan (EMI)
 Symphony No. 2/Aeneas/ Bacchus /Spider's Feast - ORTF/Jean Martinon(Erato);
 Padmavati (opera) - London Symphony Orchestra/Jean Martinon (BBC)
 Padmavati - Marilyn Horne, Nicolai Gedda/ Michel Plasson conducting (EMI)

References

 Albert Roussel, un marin musicien, 1st ed.  by Damien Top.  Séguier, 2000.
 "The Piano Music of Albert Roussel", by Henry Doskey, D.M. Indiana University, 1981. 109 p., musical examples

1869 births
1937 deaths
20th-century French composers
People from Tourcoing

Albert Roussel