Llantrisant is a town in the county borough of Rhondda Cynon Taf, within the historic county boundaries of Glamorgan, lying on the River Ely and the Afon Clun. The three saints of the town's name are SS. Illtyd and Dyfodwg. Llantrisant is a hilltop settlement, at an altitude of 174 m above sea level; the town is home to the Royal Mint. There is evidence for settlements around Llantrisant stretching back over three millennia. Two Bronze Age burial mounds are on the opposite side of the Ely Valley. A 1.05 metres tall, by 1.68 metres wide Bronze Age, standing stone, was discovered in Miskin during excavations prior to the M4 motorway construction. An Iron Age hillfort stands on Rhiwsaeson Hill; the enclosure, now known as Caerau Hillfort, measures 230 metres by 180 metres. A settlement has existed on this site from at least the beginning of the 6th century, when the poet Aneurin wrote of'the white houses of Glamorgan' when referring to Llantrisant, it was seized around 1246 by Richard de Clare. It is thought that de Clare established the borough of Llantrisant though the exact charter occurred in 1346.
In 1346, Llantrisant was granted a Royal Charter months before the archers from the town helped Edward, the Black Prince, win a victory against the French army at the Battle of Crecy. The Llantrisant longbow men were pivotal in the adoption of the English longbow as the missile weapon of choice for the English crown during the Middle Ages. Llantrisant was one of the eight boroughs constituting the Glamorgan borough following the Act of Union, a status it held until 1918. An ancient tradition called the Beating the Bounds, where local children are bounced by elders on to the boundary stones of the old borough, still occurs every seven years and has its roots set as far back as the 14th century; the rite was intended as a reminder to each generation of the importance of the borough boundaries. The children in question are held under the arms and the legs, their backside is bounced on each of the stones of the old borough, it is believed that the Beating of the Bounds started in 1346, when Llantrisant was awarded its Royal Charter.
This allowed them the freedom to trade without paying tolls within the boundaries of the former borough. The last occasion of this event was in June 2017, but the event is now seen as a purely historic tradition and social community event. At nearby Tarren Deusant is a spring with unusual petrosomatoglyph carvings of two faces, two saints, but now six are present. Llantrisant is known for its pub culture with a number of venues including The New Inn, the Wheatsheaf and the Cross Keys Hotel. In the Bull Ring was the Rock and Fountain pub, which became the home of the original Llantrisant Workingmen's Club founded in May 1953 by Seth Morgan, Freeman of Llantrisant; the focal point of the town is the Bull Ring, a commercial square in the centre of the town, used for bull-baiting, until it was disallowed in 1827 due to unruly crowds. The square contains a statue of Dr William Price a pioneer of cremation; the first workhouse in Glamorgan opened in Llantrisant in May 1784, using a number of adapted cottages on Swan Street and part of the Black Cock pub on Yr Allt, a road to the south west of the Bull Ring, between the parish church and the castle.
The Union Workhouse was built in 1884 on the Bull Ring – west of where Dr Price's statue stands today and behind the town pump. It became known as The Model House, in the rather optimistic belief that its inmates would lead a life of model Christianity. Two pubs, a shop and a cottage were demolished to make way for the expansion of the workhouse; the building closed as a workhouse in the early 1900s and first became a boarding house an inn and a general store, called County Stores. They were known as a cornflour and provisions merchant, a linen and woolen drapers selling boots and shoes; the site was bought in the 1950s by'Planet Gloves', who manufactured gloves there until the late 1960s. The Model House stood empty for many years before being bought by the local authority to convert into a craft and design centre. In 1989 the Model House re-opened as a design centre. A registered charity, Model House was funded by the Arts Council of Wales since the demise of the Arts Council of Great Britain in 1994, receiving about 35,000 visitors a year.
The ground floor contains galleries that include glass and designer jewellery from established British and Welsh artists, as well as a local painter. The upper floors have workshops that are used by individual craftspeople, whose work can be purchased either from their studio or from the ground floor shop; the Model House has a programme of art and crafts exhibitions throughout the year and hosts a varied series of workshops, where adults and children may learn the basics of a wide range of contemporary craft skills. The centre closed in December 2009 after the company which ran it, Model House Ltd, went into liquidation; the management of the building was taken over by Rhondda Cynon Taf County Borough Council, who after tackling structural problems with the roof and outer walls reopened the centre in mid 2010. Llantrisant Castle stands in parkland in the centre of the town though only one wall of the raven tower remains. Although built as a wooden fortification it was rebuilt as a stone structure around 1246 by Richard de Clare, Lord of Glamorgan.
In 1294 the castle was damaged during the uprising against the Norman overlords, led by Madog ap Llywelyn, again in 1316 by Llywelyn Bren. It is believed that the castle was destroyed in 1404 by Owain Glyndŵr though there is no written proof of the event
The Perth Mint is Australia's official bullion mint and wholly owned by the Government of Western Australia. Established on 20 June 1899, two years before Australia's Federation in 1901, the Perth Mint was the last of three Australian colonial branches of the United Kingdom's Royal Mint intended to refine gold from the gold rushes and to mint gold sovereigns and half-sovereigns for the British Empire. Along with the Royal Australian Mint, which produces coins of the Australian dollar for circulation, the Perth Mint is the older of the two mints issuing coins that are legal tender in Australia. After the foundation stone was laid in 1896 by Sir John Forrest, the Mint opened on 20 June 1899. At that time, Western Australia's population was growing due to the discovery of rich gold deposits in Coolgardie and Murchison areas of the colony; as there was little money available in Perth for which miners could exchange gold to pay for goods, the Diggers who flocked to the colony of Western Australia in huge numbers from other parts of Australia and from around the world, deposited their raw gold at the Perth Mint where it was minted into gold coins.
Although Federation occurred in 1901, the Mint remained under the jurisdiction of Great Britain until 1 July 1970, when it became a statutory authority of the Government of Western Australia. From 1899 to 1931, the Perth Mint struck more than 106 million gold sovereigns, nearly 735,000 half-sovereigns, for use as currency in Australia and throughout the British Empire; the Mint stopped making gold sovereigns when Britain abandoned the gold standard in 1931. The refinery remained busy as staff turned their skills to making fine gold bullion bars, but it was not long. During World War II, the Perth Mint began minting the Australian coinage from base metals. Up until the end of 1983, the Perth Mint manufactured much of Australia's lower-denomination coin currency; the Perth Mint achieved "arguably the purest of all gold" in 1957 when the mint produced a 13-troy-ounce proof plate of six nines - 999.999 parts of gold per thousand. The Royal Mint was so impressed that it ordered some of the gold as the benchmark for its own standards.
The Mint's new direction was formalised in 1987 with the creation of Gold Corporation by a State Act of Parliament. Under a unique agreement with the Commonwealth of Australia's Department of the Treasury, the Mint's new operator was empowered to mint and market gold and platinum Australian legal tender coinage to investors and collectors worldwide. Prime Minister Bob Hawke launched the Australian Nugget Gold Coins Series in 1987; the first day's trading yielded sales of 155,000 ounces of gold worth $103 million, well above the sales target of 130,000 ounces to the end of June. Today, the Perth Mint is a member of an elite group of world mints whose pure gold and platinum legal tender coins are trusted without question. Like the Australian Nugget, its Australian Kookaburra Silver Coin Series and Australian Lunar Gold and Silver Coin Series are extensively sought after by bullion investors worldwide. Up to 2000, the Mint's refined gold output totalled 4,500 tonnes, representing 3.25% of the total weight of gold produced by humankind.
This is about the current holdings of gold bullion in the United States Treasury's Fort Knox Bullion Depository. In 2003, the Perth Mint opened an 8,400 square metre state-of-the-art manufacturing facility next door to its original limestone building. In October 2011, the Perth Mint created the world's largest and most valuable gold coin, breaking the record held by the Royal Canadian Mint; the coin is 80 centimetres in diameter and 12 centimetres thick, made of 1,012 kilograms of 99.99% pure gold. It features, on the obverse side, the effigy of Elizabeth II, a red kangaroo on the reverse side, it is legal tender in Australia with face value A$1 million, but at the time of minting it was valued at A$53.5 million. Today, the Mint continues to provide refining and other services to the gold industry and manufactures many coin related numismatic items for investors and coin collectors, it is responsible for manufacturing and marketing most of Australia's legal tender precious metal coins, including proof quality Australian Nugget gold coins, Australian Platinum Koala coins, Australian Silver Kookaburra coins, Swan series coins and bullion.
In January 2018, the Perth Mint announced it would produce a blockchain based cryptocurrency backed by its own bullion in the next 12 to 18 months. In October 2018, a collaboration known as the Gold Industry Group began a Heart of Gold Discovery Trail in Perth.. The project included Perth Mint as a partner. Hints to Prospectors and Owners of Treatment Plants Perth Mint Certificate Program Perth Mint Swindle History of Western Australia Official Perth Mint website Perth Mint Bullion website A Comprehensive Guide to the Perth Mint 1oz Bar State Heritage record
Thailand the Kingdom of Thailand and known as Siam, is a country at the centre of the Southeast Asian Indochinese peninsula composed of 76 provinces. At 513,120 km2 and over 68 million people, Thailand is the world's 50th largest country by total area and the 21st-most-populous country; the capital and largest city is a special administrative area. Thailand is bordered to the north by Myanmar and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, to the west by the Andaman Sea and the southern extremity of Myanmar, its maritime boundaries include Vietnam in the Gulf of Thailand to the southeast, Indonesia and India on the Andaman Sea to the southwest. Although nominally a constitutional monarchy and parliamentary democracy, the most recent coup in 2014 established a de facto military dictatorship. Tai peoples migrated from southwestern China to mainland Southeast Asia from the 11th century. Various Indianised kingdoms such as the Mon, the Khmer Empire and Malay states ruled the region, competing with Thai states such as Ngoenyang, the Sukhothai Kingdom, Lan Na and the Ayutthaya Kingdom, which rivaled each other.
European contact began in 1511 with a Portuguese diplomatic mission to Ayutthaya, one of the great powers in the region. Ayutthaya reached its peak during cosmopolitan Narai's reign declining thereafter until being destroyed in 1767 in a war with Burma. Taksin reunified the fragmented territory and established the short-lived Thonburi Kingdom, he was succeeded in 1782 by Buddha Yodfa Chulaloke, the first monarch of the Chakri dynasty and founder of the Rattanakosin Kingdom, which lasted into the early 20th century. Through the 18th and 19th centuries, Siam faced pressure from France and the United Kingdom, including forced concessions of territory, but it remained the only Southeast Asian country to avoid direct Western rule. Following a bloodless revolution in 1932, Siam became a constitutional monarchy and changed its official name to "Thailand". While it joined the Allies in World War I, Thailand was an Axis satellite in World War II. In the late 1950s, a military coup revived the monarchy's influential role in politics.
Thailand became a major ally of the United States and played a key anti-communist role in the region. Apart from a brief period of parliamentary democracy in the mid-1970s, Thailand has periodically alternated between democracy and military rule. In the 21st century, Thailand endured a political crisis that culminated in two coups and the establishment of its current and 20th constitution by the military junta. Thailand is a unitary parliamentary constitutional monarchy under a military junta. Thailand is a founding member of Association of Southeast Asian Nations and remains a major ally of the US. Despite its comparatively sporadic changes in leadership, it is considered a regional power in Southeast Asia and a middle power in global affairs. With a high level of human development, the second largest economy in Southeast Asia, the 20th largest by PPP, Thailand is classified as a newly industrialized economy. Thailand the Kingdom of Thailand known as Siam, is a country at the centre of the Indochinese peninsula in Southeast Asia.
The country has always been called Mueang Thai by its citizens. By outsiders prior to 1949, it was known by the exonym Siam; the word Siam may have originated from Pali or Sanskrit श्याम or Mon ရာမည. The names Shan and A-hom seem to be variants of the same word; the word Śyâma is not its origin, but a learned and artificial distortion. Another theory is the name derives from Chinese: "Ayutthaya emerged as a dominant centre in the late fourteenth century; the Chinese called this region Xian, which the Portuguese converted into Siam." A further possibility is that Mon-speaking peoples migrating south called themselves'syem' as do the autochthonous Mon-Khmer-speaking inhabitants of the Malay Peninsula. The signature of King Mongkut reads SPPM Mongkut Rex Siamensium, giving the name "Siam" official status until 24 June 1939 when it was changed to Thailand. Thailand was renamed to Siam from 1946 to 1948. According to George Cœdès, the word Thai means "free man" in the Thai language, "differentiating the Thai from the natives encompassed in Thai society as serfs".
A famous Thai scholar argued that Thai means "people" or "human being", since his investigation shows that in some rural areas the word "Thai" was used instead of the usual Thai word "khon" for people. According to Michel Ferlus, the ethnonyms Thai/Tai would have evolved from the etymon *kri:'human being' through the following chain: *kəri: > *kəli: > *kədi:/*kədaj > *di:/*daj > *dajA > tʰajA2 or > tajA2. Michel Ferlus' work is based on some simple rules of phonetic change observable in the Sinosphere and studied for t
Coins of the Australian dollar
Coins of the Australian dollar were introduced on 14 February 1966, although they did not at that time include one-dollar or two-dollar coins. The dollar was equivalent in value to 10 shillings in the former currency. Produced by the Royal Australian Mint, all current coins portray Her Majesty Elizabeth II, Queen of Australia, on the obverse, with the present effigy having been designed by Ian Rank-Broadley; this is matched with designs by the Australian-born artist Stuart Devlin on the reverse. They now comprise 50c, 20c, 10c and 5c coins—all still referred to as'silver' though 75% copper and 25% nickel, for many years there were "bronze" 2c and 1c coins; the 50c coin had a circular shape, contained 80% silver and 20% copper, so that the material of the coin was worth more than 50c. It was made to identical dimensional specifications as the British 2/6 coin, the half crown. However, to avoid confusion among the round coins, because of its excess value, it was only produced for one year withdrawn from circulation.
It was changed to a 12-sided shape for 1969 and all following years, but the 12-sided issue was minted as a specimen piece in 1966–67 to test the design. It has since been issued in both commemorative designs; the standard designs on both versions of the coin are the same: the obverse carries the effigy of the sovereign, the reverse shows the Coat of Arms of Australia. The dodecagonal version has a mass of 15.55 g and a diameter of 31.5 mm, the round silver version has a mass of 13.28 g and diameter of 31.5 mm. 94.13 Australian 1966 round 50c coins make up a fine kilogram of silver. "Gold" one-dollar and two-dollar coins were introduced in the 1980s. The one-dollar coin was introduced in 1984; the two-dollar coin replacing a banknote, was introduced in 1988. These have content of 6 % aluminium and 92 % copper. Thus, all Australian coins in use are composed of more than half copper; the two-dollar coin is smaller in diameter than the one-dollar coin, but the two-dollar is thicker. The one- and two-cent coins were discontinued in 1991 due to the metal exceeding face value and were withdrawn from circulation.
Australian coins have medallic orientation, as do most other Commonwealth coinage, Japanese yen coinage, euro coinage. This is in contrast to coin orientation, used in United States coinage. Commemorative coins have been produced for various denominations in various years with imagery representing an event replacing the usual design on the reverse side of the coin. In some years, all the coins of that denomination are replaced with a different design for that year. In other cases, only a few million coins have the commemorative design, coins with the standard reverse are released. No commemorative issues of the 1c and 2c coins have been produced, with the exception of the 2016 issue, there have been no commemorative issues of the 5c and 10c coins. Many commemorative versions of the 50c coin have been placed in general circulation since 1970; the first $1 coin commemorative issue was in 1986, the first 20c commemorative issue in 1995, the first $2 commemorative issue in 2012. Mintages reported.
In 1992 the Mint commenced production of commemorative issues. Mintages reported for these coins vary from around 5,000 to around 125,000, with the notable exception of the four 25c coins of 2016 which have mintages of 1 million each. In 2016, to celebrate 50 years of decimal currency, a commemorative design for the obverse of the coins was released. To date this is the only issue where the commemorative design is on the obverse face rather than on the reverse face; the Royal Australian Mint releases collectable coins, one of the most famous of, the 1980-1994 gold two-hundred-dollar coin series. Australian collectable coins are all legal tender and can be used directly as currency or converted to "normal" coinage at a bank. Metals include aluminium bronze, gold and bi-metal coins. Nugget coins are issued in ounces and fractions or kilograms and come in gold and platinum, some are denominated in dollars, others by their weight value. List of people who have appeared on Australian currency Coins of the New Zealand dollar Swedish rounding
Fiji the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean about 1,100 nautical miles northeast of New Zealand's North Island. Its closest neighbours are Vanuatu to the west, New Caledonia to the southwest, New Zealand's Kermadec Islands to the southeast, Tonga to the east, the Samoas and France's Wallis and Futuna to the northeast, Tuvalu to the north. Fiji consists of an archipelago of more than 330 islands—of which 110 are permanently inhabited—and more than 500 islets, amounting to a total land area of about 18,300 square kilometres; the most outlying island is Ono-i-Lau. The two major islands, Viti Levu and Vanua Levu, account for 87% of the total population of 898,760; the capital, Suva, on Viti Levu, serves as the country's principal cruise-ship port. About three-quarters of Fijians live on Viti Levu's coasts, either in Suva or in smaller urban centres such as Nadi—where tourism is the major local industry—or Lautoka, where the sugar-cane industry is paramount.
Due to its terrain, the interior of Viti Levu is sparsely inhabited. The majority of Fiji's islands formed through volcanic activity starting around 150 million years ago; some geothermal activity still occurs today, on the islands of Vanua Taveuni. The geothermal systems on Viti Levu are non-volcanic in origin, with low-temperature surface discharges. Sabeto Hot Springs near Nadi is a good example. Humans have lived in Fiji since the second millennium BC—first Austronesians and Melanesians, with some Polynesian influences. Europeans visited Fiji from the 17th century onwards, after a brief period as an independent kingdom, the British established the Colony of Fiji in 1874. Fiji operated as a Crown colony until 1970. A military government declared a Republic in 1987 following a series of coups d'état. In a coup in 2006, Commodore Frank Bainimarama seized power; when the High Court ruled the military leadership unlawful in 2009, President Ratu Josefa Iloilo, whom the military had retained as the nominal Head of State, formally abrogated the 1997 Constitution and re-appointed Bainimarama as interim Prime Minister.
In 2009, Ratu Epeli Nailatikau succeeded Iloilo as President. After years of delays, a democratic election took place on 17 September 2014. Bainimarama's FijiFirst party won 59.2% of the vote, international observers deemed the election credible. Fiji has one of the most developed economies in the Pacific thanks to its abundant forest and fish resources, its currency is the Fijian dollar, its main sources of foreign exchange are its tourist industry, remittances from Fijians working, bottled water exports. The Ministry of Local Government and Urban Development supervises Fiji's local government, which takes the form of city and town councils. Fiji's main island is known as Viti Levu and it is from this that the name "Fiji" is derived, though the common English pronunciation is based on that of their island neighbours in Tonga, its emergence can be described as follows: Fijians first impressed themselves on European consciousness through the writings of the members of the expeditions of Cook who met them in Tonga.
They were described as formidable warriors and ferocious cannibals, builders of the finest vessels in the Pacific, but not great sailors. They inspired awe amongst the Tongans, all their Manufactures bark cloth and clubs, were valued and much in demand, they called their home Viti, but the Tongans called it Fisi, it was by this foreign pronunciation, first promulgated by Captain James Cook, that these islands are now known. "Feejee", the Anglicised spelling of the Tongan pronunciation, was used in accounts and other writings until the late 19th century, by missionaries and other travellers visiting Fiji. Located in the central Pacific Ocean, Fiji's geography has made it both a destination and a crossroads for migrations for many centuries. According to oral tradition, the indigenous Fijians of today are descendants of the chief Lutunasobasoba and those who arrived with him on the Kaunitoni canoe. Landing at what is now Vuda, the settlers moved inland to the Nakauvadra mountains. Though this oral tradition has not been independently substantiated, the Fijian government promotes it, many tribes today claim to be descended from the children of Lutunasobasoba.
Pottery art from Fijian towns shows that Fiji was settled by Austronesian peoples before or around 3500 to 1000 BC, with Melanesians following around a thousand years although the question of Pacific migration still lingers. It is believed that the Lapita people or the ancestors of the Polynesians settled the islands first but not much is known of what became of them after the Melanesians arrived. Archeological evidence shows signs of settlement on Moturiki Island from 600 BC and as far back as 900 BC. Aspects of Fijian culture are similar to the Melanesian culture of the western Pacific but have a stronger connection to the older Polynesian cultures. Trade between Fiji and neighbouring archipelagos long before European contact is testified by the canoes made from native Fijian trees found in Tonga and Tongan words being part of the language of the Lau group of islands. Pots made in Fiji have been found in Samoa and the Marquesas Islands. In the 10th century, the Tu'i Tonga Empire was established in Tonga, Fiji came within its sphere of influence.
The Tongan influence brought Polynesian cu
A laboratory is a facility that provides controlled conditions in which scientific or technological research and measurement may be performed. Laboratories used for scientific research take many forms because of the differing requirements of specialists in the various fields of science and engineering. A physics laboratory might contain a particle accelerator or vacuum chamber, while a metallurgy laboratory could have apparatus for casting or refining metals or for testing their strength. A chemist or biologist might use a wet laboratory, while a psychologist's laboratory might be a room with one-way mirrors and hidden cameras in which to observe behavior. In some laboratories, such as those used by computer scientists, computers are used for either simulations or the analysis of data. Scientists in other fields will use still other types of laboratories. Engineers use laboratories as well to design and test technological devices. Scientific laboratories can be found as research room and learning spaces in schools and universities, government, or military facilities, aboard ships and spacecraft.
Despite the underlying notion of the lab as a confined space for experts, the term "laboratory" is increasingly applied to workshop spaces such as Living Labs, Fab Labs, or Hackerspaces, in which people meet to work on societal problems or make prototypes, working collaboratively or sharing resources. This development is inspired by new, participatory approaches to science and innovation and relies on user-centred design methods and concepts like Open innovation or User innovation. One distinctive feature of work in Open Labs is phenomena of translation, driven by the different backgrounds and levels of expertise of the people involved. Early instances of "laboratories" recorded in English involved alchemy and the preparation of medicines; the emergence of Big Science during World War II increased the size of laboratories and scientific equipment, introducing particle accelerators and similar devices. The earliest laboratory according to the present evidence is a home laboratory of Pythagoras of Samos, the well-known Greek philosopher and scientist.
This laboratory was created when Pythagoras conducted an experiment about tones of sound and vibration of string. In the painting of Louis Pasteur by Albert Edelfelt in 1885, Louis Pasteur is shown comparing a note in his left hand with a bottle filled with a solid in his right hand, not wearing any personal protective equipment. Researching in teams started in the 19th century, many new kinds of equipment were developed in the 20th century. A 16th century underground alchemical laboratory was accidentally discovered in the year 2002. Rudolf II, Holy Roman Emperor was believed to be the owner; the laboratory is preserved as a museum in Prague. Laboratory techniques are the set of procedures used on natural sciences such as chemistry, physics to conduct an experiment, all of them follow the scientific method. Laboratory equipment refers to the various tools and equipment used by scientists working in a laboratory: The classical equipment includes tools such as Bunsen burners and microscopes as well as specialty equipment such as operant conditioning chambers, spectrophotometers and calorimeters.
Chemical laboratorieslaboratory glassware such as the beaker or reagent bottle Analytical devices as HPLC or spectrophotometersMolecular biology laboratories + Life science laboratoriesAutoclave Microscope Centrifuges Shakers & mixers Pipette Thermal cyclers Photometer Refrigerators and Freezers Universal testing machine ULT Freezers Incubators Bioreactor Biological safety cabinets Sequencing instruments Fume hoods Environmental chamber Humidifier Weighing scale Reagents Pipettes tips Polymer consumables for small volumes sterileLaboratory equipment is used to either perform an experiment or to take measurements and gather data. Larger or more sophisticated equipment is called a scientific instrument; the title of laboratory is used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories. These notably include: Film laboratory or Darkroom Clandestine lab for the production of illegal drugs Computer lab Crime lab used to process crime scene evidence Language laboratory Medical laboratory Public health laboratory Industrial laboratory In many laboratories, hazards are present.
Laboratory hazards might include poisons. Therefore, safety precautions are vitally important. Rules exist to minimize the individual's risk, safety equipment is used to protect the lab users from injury or to assist in responding to an emergency; the Occupational Safety and Health Administration in the United States, recognizing the unique characteristics of the laboratory workplace, has tailored a standard for occupational exposure to hazardous chemicals in laboratories. This standard is referred to as the "Laboratory Standard". Under this standard, a laboratory is required to produce a Chemical Hygiene Plan which addresses the specific hazards found in its location, its approach to them. In determining the proper Chemical Hygiene Plan for a particular business or laboratory, it is necessary to understand the requirements of the standard, evaluation of the current safety and environmental practi
A hologram is an image that appears to be three dimensional and which can be seen with the naked eye. Holography is the practice of making holograms. A hologram is a photographic recording of a light field, rather than an image formed by a lens; the holographic medium, i.e. the object produced by a holographic process is unintelligible when viewed under diffuse ambient light. It is an encoding of the light field as an interference pattern of variations in the opacity, density, or surface profile of the photographic medium; when suitably lit, the interference pattern diffracts the light into an accurate reproduction of the original light field, the objects that were in it exhibit visual depth cues such as parallax and perspective that change realistically with the relative position of the observer. That is, the view of the image from different angles represents the subject viewed from similar angles. In its pure form, holography requires the use of laser light for illuminating the subject and for viewing the finished hologram.
A microscopic level of detail throughout the recorded scene can be reproduced. In common practice, major image quality compromises are made to eliminate the need for laser illumination to view the hologram, in some cases, to make it. Holographic portraiture resorts to a non-holographic intermediate imaging procedure, to avoid the hazardous high-powered pulsed lasers otherwise needed to optically "freeze" moving subjects as as the motion-intolerant holographic recording process requires. Holograms can now be computer-generated to show objects or scenes that never existed. Holography is distinct from lenticular and other earlier autostereoscopic 3D display technologies, which can produce superficially similar results but are based on conventional lens imaging. Images requiring the aid of special glasses or other intermediate optics, stage illusions such as Pepper's Ghost and other unusual, baffling, or magical images are incorrectly called holograms; the Hungarian-British physicist Dennis Gabor was awarded the Nobel Prize in Physics in 1971 "for his invention and development of the holographic method".
His work, done in the late 1940s, was built on pioneering work in the field of X-ray microscopy by other scientists including Mieczysław Wolfke in 1920 and William Lawrence Bragg in 1939. The discovery was an unexpected result of research into improving electron microscopes at the British Thomson-Houston Company in Rugby and the company filed a patent in December 1947; the technique as invented is still used in electron microscopy, where it is known as electron holography, but optical holography did not advance until the development of the laser in 1960. The word holography comes from the Greek words ὅλος and γραφή; the development of the laser enabled the first practical optical holograms that recorded 3D objects to be made in 1962 by Yuri Denisyuk in the Soviet Union and by Emmett Leith and Juris Upatnieks at the University of Michigan, USA. Early holograms used silver halide photographic emulsions as the recording medium, they were not efficient as the produced grating absorbed much of the incident light.
Various methods of converting the variation in transmission to a variation in refractive index were developed which enabled much more efficient holograms to be produced. Several types of holograms can be made. Transmission holograms, such as those produced by Leith and Upatnieks, are viewed by shining laser light through them and looking at the reconstructed image from the side of the hologram opposite the source. A refinement, the "rainbow transmission" hologram, allows more convenient illumination by white light rather than by lasers. Rainbow holograms are used for security and authentication, for example, on credit cards and product packaging. Another kind of common hologram, the reflection or Denisyuk hologram, can be viewed using a white-light illumination source on the same side of the hologram as the viewer and is the type of hologram seen in holographic displays, they are capable of multicolour-image reproduction. Specular holography is a related technique for making three-dimensional images by controlling the motion of specularities on a two-dimensional surface.
It works by reflectively or refractively manipulating bundles of light rays, whereas Gabor-style holography works by diffractively reconstructing wavefronts. Most holograms produced are of static objects but systems for displaying changing scenes on a holographic volumetric display are now being developed. Holograms can be used to store and process information optically. In its early days, holography required high-power expensive lasers, but nowadays, mass-produced low-cost semi-conductor or diode lasers, such as those found in millions of DVD recorders and used in other common applications, can be used to make holograms and have made holography much more accessible to low-budget researchers and dedicated hobbyists, it was thought that it would be possible to use X-rays to make holograms of small objects and view them using visible light. Today, holograms with x-rays are generated by using synchrotrons or x-ray free-electron lasers as radiation sources and pixelated detectors such as CCDs as recording medium.
The reconstruction is retrieved via computation. Due to the shorter wavelength of x-rays compared to visible light, this approach allows imaging objects with higher spatial resolution; as free-electron lasers can provide ultrashort and x-ray pulses in the range of femtoseconds which are intense and coherent, x-ray holography