paragraph_text: Currently printed denominations are $1, $2, $5, $10, $20, $50, and $100. Notes above the $100 denomination stopped being printed in 1946 and were officially withdrawn from circulation in 1969. These notes were used primarily in inter-bank transactions or by organized crime; it was the latter usage that prompted President Richard Nixon to issue an executive order in 1969 halting their use. With the advent of electronic banking, they became less necessary. Notes in denominations of $500, $1,000, $5,000, $10,000 and $100,000 were all produced at one time; see large denomination bills in U.S. currency for details. These notes are now collectors' items and are worth more than their face value to collectors.

paragraph_text: The picture below shows the Shrimp device, detonated on March 1, 1954 at Bikini, as the Castle Bravo test. Its 15-megaton explosion was the largest ever by the United States. The silhouette of a man is shown for scale. The device is supported from below, at the ends. The pipes going into the shot cab ceiling, which appear to be supports, are actually diagnostic light pipes. The eight pipes at the right end (1) sent information about the detonation of the primary. Two in the middle (2) marked the time when x-radiation from the primary reached the radiation channel around the secondary. The last two pipes (3) noted the time radiation reached the far end of the radiation channel, the difference between (2) and (3) being the radiation transit time for the channel.

paragraph_text: On January 1, 1973, the Central Bank of Nigeria introduced notes for 50 kobo, 1, 5, 10 and 20 naira. The 50 kobo notes were last issued in 1989. In 1991, 50 naira notes were issued, followed by 100 naira in 1999, 200 naira in 2000, 500 naira in 2001 and 1000 naira on October 12, 2005.

paragraph_text: The Reserve Bank of Australia (RBA), on 14 January 1960, became the Australian central bank and banknote issuing authority, when the Reserve Bank Act 1959 (23 April 1959) removed the central banking functions from the Commonwealth Bank.

paragraph_text: The primary objective of the European Central Bank, as mandated in Article 2 of the Statute of the ECB, is to maintain price stability within the Eurozone. The basic tasks, as defined in Article 3 of the Statute, are to define and implement the monetary policy for the Eurozone, to conduct foreign exchange operations, to take care of the foreign reserves of the European System of Central Banks and operation of the financial market infrastructure under the TARGET2 payments system and the technical platform (currently being developed) for settlement of securities in Europe (TARGET2 Securities). The ECB has, under Article 16 of its Statute, the exclusive right to authorise the issuance of euro banknotes. Member states can issue euro coins, but the amount must be authorised by the ECB beforehand.

paragraph_text: From 1978 until 1988, an image of Newton designed by Harry Ecclestone appeared on Series D £1 banknotes issued by the Bank of England (the last £1 notes to be issued by the Bank of England). Newton was shown on the reverse of the notes holding a book and accompanied by a telescope, a prism and a map of the Solar System.

paragraph_text: The £1 note is currently the smallest denomination of banknote issued by The Royal Bank of Scotland. The bank ceased regular production of £1 notes in 2001; the denomination is still in circulation although rarely seen in cash transactions today.

paragraph_text: Twenty pound notes were introduced by the Bank of England for the first time in 1725. The earliest notes were handwritten, and were issued to individuals as needed. These notes were written on one side only and bore the name of the payee, the date, and the signature of the issuing cashier. With the exception of the Restriction Period between 1797 and 1821 when the French Revolutionary Wars and the Napoleonic Wars caused a bullion shortage, these notes could be exchanged in full, or in part, for an equivalent amount of gold when presented at the bank. If redeemed in part, the banknote would be signed to indicate the amount that had been redeemed. From 1853 printed notes replaced handwritten notes, with the declaration ``I promise to pay the bearer on demand the sum of twenty pounds ''replacing the name of the payee. This declaration remains on Bank of England banknotes to this day. A printed signature of one of three cashiers appeared on the printed notes, though this was replaced by the signature of the Chief Cashier from 1870 onward.

paragraph_text: Pokhran - II was the series of five nuclear bomb test explosions conducted by India at the Indian Army's Pokhran Test Range in May 1998. It was the second Indian nuclear test; the first test, code - named Smiling Buddha, was conducted in May 1974.

paragraph_text: In 1970 the country switched its currency from the Bermudian pound to the Bermudian dollar, which is pegged at par with the US dollar. US notes and coins are used interchangeably with Bermudian notes and coins within the islands for most practical purposes; however, banks levy an exchange rate fee for the purchase of US dollars with Bermudian dollars. Bermudian notes carry the image of Queen Elizabeth II. The Bermuda Monetary Authority is the issuing authority for all banknotes and coins, and regulates financial institutions. The Royal Naval Dockyard Museum holds a permanent exhibition of Bermuda notes and coins.

paragraph_text: The U.S. Constitution provides that Congress shall have the power to "borrow money on the credit of the United States". Congress has exercised that power by authorizing Federal Reserve Banks to issue Federal Reserve Notes. Those notes are "obligations of the United States" and "shall be redeemed in lawful money on demand at the Treasury Department of the United States, in the city of Washington, District of Columbia, or at any Federal Reserve bank". Federal Reserve Notes are designated by law as "legal tender" for the payment of debts. Congress has also authorized the issuance of more than 10 other types of banknotes, including the United States Note and the Federal Reserve Bank Note. The Federal Reserve Note is the only type that remains in circulation since the 1970s.

paragraph_text: Regular government issues commenced in 1948 in denominations of 1, 5, 10 and 100 rupees. The government continued to issue 1 rupee notes until the 1980s but other note issuing was taken over by the State Bank of Pakistan in 1953, when 2, 5, 10 and 100 rupees notes were issued. Only a few 2 rupees notes were issued. 50 rupees notes were added in 1957, with 2 rupees notes reintroduced in 1985. In 1986, 500 rupees notes were introduced, followed by 1000 rupees the next year. 2 and 5 rupees notes were replaced by coins in 1998 and 2002. 20 rupee notes were added in 2005, followed by 5000 rupees in 2006. Until 1971, Pakistani banknotes were bilingual, featuring Bengali translation of the Urdu text (where the currency was called taka instead of rupee), since Bengali was the state language of East Pakistan (now Bangladesh).

paragraph_text: The Federal Reserve System (also known as the Federal Reserve or simply the Fed) is the central banking system of the United States. It was created on December 23, 1913, with the enactment of the Federal Reserve Act, after a series of financial panics (particularly the panic of 1907) led to the desire for central control of the monetary system in order to alleviate financial crises. Over the years, events such as the Great Depression in the 1930s and the Great Recession during the 2000s have led to the expansion of the roles and responsibilities of the Federal Reserve System.

paragraph_text: The Bank of England £5 note, also known as a fiver, is a banknote of the pound sterling. It is the smallest denomination of banknote issued by the Bank of England. In September 2016, a new polymer note was introduced, featuring the image of Queen Elizabeth II on the obverse and a portrait of Winston Churchill on the reverse. The old paper note, first issued in 2002 and bearing the image of prison reformer Elizabeth Fry on the reverse, was phased out and ceased to be legal tender after 5 May 2017.

paragraph_text: The Federal Reserve Act (ch. 6, 38 Stat. 251, enacted December 23, 1913, 12 U.S.C. ch. 3) is an Act of Congress that created and established the Federal Reserve System, the central banking system of the United States, and which created the authority to issue Federal Reserve Notes (now commonly known as the U.S. Dollar) and Federal Reserve Bank Notes as legal tender. The Act was signed into law by President Woodrow Wilson.

paragraph_text: The banks in effect borrow cash and must pay it back; the short durations allow interest rates to be adjusted continually. When the repo notes come due the participating banks bid again. An increase in the quantity of notes offered at auction allows an increase in liquidity in the economy. A decrease has the contrary effect. The contracts are carried on the asset side of the European Central Bank's balance sheet and the resulting deposits in member banks are carried as a liability. In layman terms, the liability of the central bank is money, and an increase in deposits in member banks, carried as a liability by the central bank, means that more money has been put into the economy.[a]

paragraph_text: The British Crown dependencies of Guernsey and Jersey produce their own local issues of sterling: the ``Guernsey pound ''and the`` Jersey pound''. The pound sterling is also used in the Isle of Man (alongside the Manx pound), Gibraltar (alongside the Gibraltar pound), the Falkland Islands (alongside the Falkland Islands pound), Saint Helena and Ascension Island in Saint Helena, Ascension and Tristan da Cunha (alongside the Saint Helena pound). The Bank of England is the central bank for the pound sterling, issuing its own coins and banknotes, and regulating issuance of banknotes by private banks in Scotland and Northern Ireland. Banknotes issued by other jurisdictions are not regulated by the Bank of England; local governments use Bank of England notes as backing for local issuance by allowing them to be exchanged 1: 1 at face value.

paragraph_text: During the early years of the Cold War from 1946 to 1958, the United States tested 67 nuclear weapons at its Pacific Proving Grounds located in the Marshall Islands, including the largest atmospheric nuclear test ever conducted by the U.S., code named Castle Bravo. "The bombs had a total yield of 108,496 kilotons, over 7,200 times more powerful than the atomic weapons used during World War II." With the 1952 test of the first U.S. hydrogen bomb, code named "Ivy Mike," the island of Elugelab in the Enewetak atoll was destroyed. In 1956, the United States Atomic Energy Commission regarded the Marshall Islands as "by far the most contaminated place in the world."

paragraph_text: The Pokhran - II tests were a series of five nuclear bomb test explosions conducted by India at the Indian Army's Pokhran Test Range in May 1998. It was the second instance of nuclear testing conducted by India; the first test, code - named Smiling Buddha, was conducted in May 1974.

paragraph_text: Fifty pound notes were introduced by the Bank of England for the first time in 1725. The earliest notes were handwritten and were issued as needed to individuals. These notes were written on one side only and bore the name of the payee, the date, and the signature of the issuing cashier. With the exception of the Restriction Period between 1797 and 1821, when the French Revolutionary Wars and the Napoleonic Wars caused a bullion shortage, these notes could be exchanged in full, or in part, for an equivalent amount of gold when presented at the bank. If redeemed in part, the banknote would be signed to indicate the amount that had been redeemed. From 1853 printed notes replaced handwritten notes, with the declaration ``I promise to pay the bearer on demand the sum of fifty pounds ''replacing the name of the payee. This declaration remains on Bank of England banknotes to this day. A printed signature of one of three cashiers appeared on the printed notes, although this was replaced by the signature of the Chief Cashier from 1870 onward.

Question: What are the notes issued by the current central bank of the country that conducted the Castle Bravo test?
Answer: obligations of the United States