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Pitch (resin)
Pitch is a viscoelastic polymer which can be natural or manufactured, derived from petroleum, coal tar, or plants. Various forms of pitch may also be called tar, bitumen, or asphalt. Pitch produced from plants is also known as resin. Some products made from plant resin are also known as rosin. Uses Pitch was traditionally used to help caulk the seams of wooden sailing vessels (see shipbuilding), and to coat earthenware vessels for the preservation of wine. Pitch may also be used to waterproof wooden containers and in the making of torches. Petroleum-derived pitch is black in colour, hence the adjectival phrase, "pitch-black". The viscoelastic properties of pitch make it well suited for the polishing of high-quality optical lenses and mirrors. In use, the pitch is formed into a lap or polishing surface, which is charged with iron oxide ( Jewelers' rouge) or cerium oxide. The surface to be polished is pressed into the pitch, then rubbed against the surface so formed. The abil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viscoelastic
In materials science and continuum mechanics, viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. Viscous materials, like water, resist shear flow and strain linearly with time when a stress is applied. Elastic materials strain when stretched and immediately return to their original state once the stress is removed. Viscoelastic materials have elements of both of these properties and, as such, exhibit time-dependent strain. Whereas elasticity is usually the result of bond stretching along crystallographic planes in an ordered solid, viscosity is the result of the diffusion of atoms or molecules inside an amorphous material.Meyers and Chawla (1999): "Mechanical Behavior of Materials", 98-103. Background In the nineteenth century, physicists such as Maxwell, Boltzmann, and Kelvin researched and experimented with creep and recovery of glasses, metals, and rubbers. Viscoelasticity was further examined in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Queensland
, mottoeng = By means of knowledge and hard work , established = , endowment = A$224.3 million , budget = A$2.1 billion , type = Public research university , chancellor = Peter Varghese , vice_chancellor = Deborah Terry , city = Brisbane, Queensland, Australia , students = 55,305 (2019) , undergrad = 35,051 (2019) , postgrad = 19,939 (2019) , faculty = 2,854 , campus = Multiple sites , colours = Purple , affiliations = Group of Eight Universitas 21 ASAIHL EdX , website = , logo = Logo of the University of Queensland.svg , coor = The University of Queensland (UQ, or Queensland University) is a public research university located primarily in Brisbane, the capital city of the Australian state of Queensland. Founded in 1909 by the Queensland parliament, UQ is one of the six sandstone universities, an informal designation of the oldest university in each state. As per 2023, The University of Queensland is ranked as 2nd in Australia and 42nd in the world. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pine
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts 187 species names of pines as current, together with more synonyms. The American Conifer Society (ACS) and the Royal Horticultural Society accept 121 species. Pines are commonly found in the Northern Hemisphere. ''Pine'' may also refer to the lumber derived from pine trees; it is one of the more extensively used types of lumber. The pine family is the largest conifer family and there are currently 818 named cultivars (or Trinomial nomenclature, trinomials) recognized by the ACS. Description Pine trees are evergreen, coniferous resinous trees (or, rarely, shrubs) growing tall, with the majority of species reaching tall. The smallest are Siberian dwarf pine and Potosi pinyon, and the tallest is an tall ponderosa pine lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birch-tar
Birch tar or birch pitch is a substance (liquid when heated) derived from the dry distillation of the bark of the birch tree. Compounds It is composed of phenols such as guaiacol, cresol, xylenol, and creosol. Ancient and modern uses Birch tar was used widely as an adhesive as early as the Middle Paleolithic to early Mesolithic era. Neanderthals produced tar through the dry distillation of birch bark as early as 200,000 years ago. A study from 2019 showed that birch tar production can be a very simple process, merely involving the burning of birch bark near smooth vertical surfaces in open air conditions. A rare find from the Dutch North Sea shows that Neanderthals used birch bark tar as a backing on small 'domestic' stone tools. Birch tar also has been used as a disinfectant, in leather dressing, and in medicine. 5,000-year-old chewing gum made from birch bark tar and still bearing tooth imprints, has been found in Kierikki in Finland. Genetic material retained in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charcoal
Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, called charcoal burning, often by forming a charcoal kiln, the heat is supplied by burning part of the starting material itself, with a limited supply of oxygen. The material can also be heated in a closed retort. Modern "charcoal" briquettes used for outdoor cooking may contain many other additives, e.g. coal. This process happens naturally when combustion is incomplete, and is sometimes used in radiocarbon dating. It also happens inadvertently while burning wood, as in a fireplace or wood stove. The visible flame in these is due to combustion of the volatile gases exuded as the wood turns into charcoal. The soot and smoke commonly given off by wood fires result from incomplete combustion of those volatiles. Charcoal burns at a highe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dry Distillation
Dry distillation is the heating of solid materials to produce gaseous products (which may condense into liquids or solids). The method may involve pyrolysis or thermolysis, or it may not (for instance, a simple mixture of ice and glass could be separated without breaking any chemical bonds, but organic matter contains a greater diversity of molecules, some of which are likely to break). If there are no chemical changes, just phase changes, it resembles classical distillation, although it will generally need higher temperatures. Dry distillation in which chemical changes occur is a type of destructive distillation or cracking. Uses The method has been used to obtain liquid fuels from coal and wood. It can also be used to break down mineral salts such as sulfates () through thermolysis, in this case producing sulfur dioxide (SO2) or sulfur trioxide (SO3) gas which can be dissolved in water to obtain sulfuric acid. By this method sulfuric acid was first identified and artificial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winchester College
Winchester College is a public school (fee-charging independent day and boarding school) in Winchester, Hampshire, England. It was founded by William of Wykeham in 1382 and has existed in its present location ever since. It is the oldest of the nine schools considered by the Clarendon Commission. The school is currently undergoing a transition to become co-educational and to accept day pupils, having previously been a boys' boarding school for over 600 years. The school was founded to provide an education for 70 scholars. Gradually numbers rose, a choir of 16 "quiristers" being added alongside paying pupils known as "commoners". Numbers expanded greatly in the 1860s with the addition of ten boarding houses. The scholars continue to live in the school's medieval buildings, which consist of two courtyards, a chapel, and a cloisters. A Wren-style classroom building named "School" was added in the 17th century. An art school ("museum"), science school, and music school wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RTÉ News
RTÉ News and Current Affairs ( ga, Nuacht agus Cúrsaí Reatha RTÉ), also known as RTÉ News (''Nuacht RTÉ''), is the national news service provided by Irish public broadcaster Raidió Teilifís Éireann. Its services include local, national, European and international news, investigative journalism and current affairs programming for RTÉ television, radio, online, podcasts, on-demand and for independent Irish language public broadcaster TG4. It is the largest and most popular news source in Ireland – with 77% of the Irish public regarding it as their main source of both Irish and international news. It broadcasts in English, Irish and Irish Sign Language. The organisation is also a source of commentary on current affairs. The division is based at the RTÉ Television Centre in Donnybrook, Dublin; however, the station also operates regional bureaux across Ireland and the world. History Early history On 1 January, 1926, 2RN, Ireland's first radio station, began broadc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ireland
Ireland ( ; ga, Éire ; Ulster-Scots: ) is an island in the North Atlantic Ocean, in north-western Europe. It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. Ireland is the second-largest island of the British Isles, the third-largest in Europe, and the twentieth-largest on Earth. Geopolitically, Ireland is divided between the Republic of Ireland (officially named Ireland), which covers five-sixths of the island, and Northern Ireland, which is part of the United Kingdom. As of 2022, the population of the entire island is just over 7 million, with 5.1 million living in the Republic of Ireland and 1.9 million in Northern Ireland, ranking it the second-most populous island in Europe after Great Britain.The 2022 population of the Republic of Ireland was 5,123,536 and that of Northern Ireland in 2021 was 1,903,100. These are Census data from the official governmental statistics agencies in the respecti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trinity College, Dublin
, name_Latin = Collegium Sanctae et Individuae Trinitatis Reginae Elizabethae juxta Dublin , motto = ''Perpetuis futuris temporibus duraturam'' (Latin) , motto_lang = la , motto_English = It will last into endless future times , founder = Queen Elizabeth I , established = , named_for = The Holy Trinity.The Trinity was the patron of The Dublin Guild Merchant, primary instigators of the foundation of the University, the arms of which guild are also similar to those of the College. , previous_names = , status = , architect = , architectural_style =Neoclassical architecture , colours = , gender = , sister_colleges = St. John's College, CambridgeOriel College, Oxford , freshman_dorm = , head_label = , head = , master = , vice_head_label = , vice_head = , warden = ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernest Walton
Ernest Thomas Sinton Walton (6 October 1903 – 25 June 1995) was an Irish physicist and Nobel laureate. He is best known for his work with John Cockcroft to construct one of the earliest types of particle accelerator, the Cockcroft–Walton generator. In experiments performed at Cambridge University in the early 1930s using the generator, Walton and Cockcroft became the first team to use a particle beam to transform one element to another. According to their Nobel Prize citation: "Thus, for the first time, a nuclear transmutation was produced by means entirely under human control." Early years Ernest Walton was born in Abbeyside, Dungarvan, County Waterford to a Methodist minister father, Rev John Walton (1874–1936) and Anna Sinton (1874–1906). In those days a general clergyman's family moved once every three years, and this practice carried Ernest and his family, while he was a small child, to Rathkeale, County Limerick (where his mother died) and to County Monaghan. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Scientist
''New Scientist'' is a magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organisation publishes a monthly Dutch-language edition. First published on 22 November 1956, ''New Scientist'' has been available in online form since 1996. Sold in retail outlets (paper edition) and on subscription (paper and/or online), the magazine covers news, features, reviews and commentary on science, technology and their implications. ''New Scientist'' also publishes speculative articles, ranging from the technical to the philosophical. ''New Scientist'' was acquired by Daily Mail and General Trust (DMGT) in March 2021. History Ownership The magazine was founded in 1956 by Tom Margerison, Max Raison and Nicholas Harrison as ''The New Scientist'', with Issue 1 on 22 November 1956, priced at one shilling (a twentieth of a pound in pre-decimal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
