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Gaslight
Gas lighting is the production of artificial light from combustion of a gaseous fuel, such as hydrogen, methane, carbon monoxide, propane, butane, acetylene, ethylene, coal gas (town gas) or natural gas. The light is produced either directly by the flame, generally by using special mixes (typically propane or butane) of illuminating gas to increase brightness, or indirectly with other components such as the gas mantle or the limelight, with the gas primarily functioning as a heat source for the incandescence of the gas mantle or lime. Before electricity became sufficiently widespread and economical to allow for general public use, gas was the most prevalent method of outdoor and indoor lighting in cities and suburbs, areas where the infrastructure for distribution of the gaseous fuel was practical. When gas lighting was prevalent, the most common fuels for gas lighting were wood gas, coal gas and, in limited cases, water gas. Early gas lights were ignited manually by lamplight ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illuminating Gas
The history of gaseous fuel, important for lighting, heating, and cooking purposes throughout most of the 19th century and the first half of the 20th century, began with the development of analytical and pneumatic chemistry in the 18th century. The manufacturing process for "synthetic fuel gases" (also known as "manufactured fuel gas", "manufactured gas" or simply "gas") typically consisted of the gasification of combustible materials, usually coal, but also wood and oil. The coal was gasified by heating the coal in enclosed ovens with an oxygen-poor atmosphere. The fuel gases generated were mixtures of many chemical substances, including hydrogen, methane, carbon monoxide and ethylene, and could be burnt for heating and lighting purposes. Coal gas, for example, also contains significant quantities of unwanted sulfur and ammonia compounds, as well as heavy hydrocarbons, and so the manufactured fuel gases needed to be purified before they could be used. The first attempts to manufa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamplighter
A lamplighter is a person employed to light and maintain candle or, later, gas street lights. Very few exist today as most gas street lighting has long been replaced by electric lamps. Function Lights were lit each evening, generally by means of a wick on a long pole. At dawn, the lamplighter would return to put them out using a small hook on the same pole. Early street lights were generally candles, oil, and similar consumable liquid or solid lighting sources with wicks. Other duties Another lamplighter duty was to carry a ladder and renew the candles, oil, or gas mantles. In some communities, lamplighters served in a role akin to a town watchman; in others, it may have been seen as little more than a sinecure. In the 19th century, gas lights became the dominant form of street lighting. Early gaslights required lamplighters, but eventually systems were developed which allowed the lights to operate automatically. Today Today a lamplighter is an extremely rare job. In Bres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal Gas
Coal gas is a flammable gaseous fuel made from coal and supplied to the user via a piped distribution system. It is produced when coal is heated strongly in the absence of air. Town gas is a more general term referring to manufactured gaseous fuels produced for sale to consumers and municipalities. The original coal gas was produced by the coal gasification reaction, and thus the burnable component consisted of a roughly equal molecular mixture of carbon monoxide and hydrogen. Thus, coal gas was highly toxic. Other compositions contain additional calorific gases such as methane, produced by the Fischer-Tropsch process, and volatile hydrocarbons together with small quantities of non-calorific gases such as carbon dioxide and nitrogen. Prior to the development of natural gas supply and transmission—during the 1940s and 1950s in the United States and during the late 1960s and 1970s in the United Kingdom and Australia—almost all gas for fuel and lighting was manufactured fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Street Lighting
A street light, light pole, lamp pole, lamppost, street lamp, light standard, or lamp standard is a raised source of light on the edge of a road or path. Similar lights may be found on a railway platform. When urban electric power distribution became ubiquitous in developed countries in the 20th century, lights for urban streets followed, or sometimes led. Many lamps have light-sensitive photocells that activate the lamp automatically when needed, at times when there is little-to-no ambient light, such as at dusk, dawn, or at the onset of dark weather conditions. This function in older lighting systems could be performed with the aid of a solar dial. Many street light systems are being connected underground instead of wiring from one utility pole, utility post to another. Street lights are an important source of public security lighting intended to reduce crime. History Preindustrial era Early lamps were used by Greek and Roman civilizations, where light primarily served t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Density
In physics, energy density is the amount of energy stored in a given system or region of space per unit volume. It is sometimes confused with energy per unit mass which is properly called specific energy or . Often only the ''useful'' or extractable energy is measured, which is to say that inaccessible energy (such as rest mass energy) is ignored. In cosmological and other general relativistic contexts, however, the energy densities considered are those that correspond to the elements of the stress–energy tensor and therefore do include mass energy as well as energy densities associated with pressure. Energy per unit volume has the same physical units as pressure and in many situations is synonymous. For example, the energy density of a magnetic field may be expressed as and behaves like a physical pressure. Likewise, the energy required to compress a gas to a certain volume may be determined by multiplying the difference between the gas pressure and the external pressure by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spring And Autumn Period
The Spring and Autumn period was a period in Chinese history from approximately 770 to 476 BC (or according to some authorities until 403 BC) which corresponds roughly to the first half of the Eastern Zhou period. The period's name derives from the ''Spring and Autumn Annals'', a chronicle of the state of Lu between 722 and 479 BCE, which tradition associates with Confucius (551–479 BCE). During this period, the Zhou royal authority over the various feudal states eroded as more and more dukes and marquesses obtained ''de facto'' regional autonomy, defying the king's court in Luoyi and waging wars amongst themselves. The gradual Partition of Jin, one of the most powerful states, marked the end of the Spring and Autumn period and the beginning of the Warring States period. Background In 771 BCE, a Quanrong invasion in coalition with the states of Zeng and Shen — the latter polity being the fief of the grandfather of the disinherited crown prince Yijiu — destroyed the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chronicles Of Huayang
The ''Chronicles of Huayang'' or ''Huayang Guo Zhi'' () is the oldest extant gazetteer of a region of China. It was compiled by Chang Qu during the Jin Dynasty. It contains roughly 110,000 characters. Its contents comprise history, geography and biographies of the Sichuan region. It was used by the Liu Song Dynasty historian Pei Songzhi in his annotations to the '' Records of the Three Kingdoms'', and by the Tang Dynasty prince Li Xian when he wrote his commentaries on the '' Book of the Later Han''. The ''Chronicles of Huayang'' is also rendered in English as: * ''Annals of Huayang Country'' * ''Huayang National Annals'' * ''Records of the States South of Mount Hua'' * ''Annals of the Kingdoms South of Mount Hua'' Hong Liangji said that ''Chronicles of Huayang'' is one of the oldest extant Chinese gazetteers, along with the ''Yue Jue Shu'' (). Contents There are twelve chapters in ''Chronicles of Huayang'', the first four are on the history and descriptions of ancient politie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bamboo
Bamboos are a diverse group of evergreen perennial flowering plants making up the subfamily Bambusoideae of the grass family Poaceae. Giant bamboos are the largest members of the grass family. The origin of the word "bamboo" is uncertain, but it probably comes from the Dutch or Portuguese language, which originally borrowed it from Malay or Kannada. In bamboo, as in other grasses, the internodal regions of the stem are usually hollow and the vascular bundles in the cross-section are scattered throughout the stem instead of in a cylindrical arrangement. The dicotyledonous woody xylem is also absent. The absence of secondary growth wood causes the stems of monocots, including the palms and large bamboos, to be columnar rather than tapering. Bamboos include some of the fastest-growing plants in the world, due to a unique rhizome-dependent system. Certain species of bamboo can grow within a 24-hour period, at a rate of almost an hour (equivalent to 1 mm every 90 seco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sesame Oil
Sesame oil is an edible vegetable oil derived from sesame seeds. The oil is one of the earliest-known crop-based oils. Worldwide mass modern production is limited due to the inefficient manual harvesting process required to extract the oil. Oil made from raw seeds, which may or may not be cold-pressed, is used as a cooking oil. Oil made from toasted seeds is used for its distinctive nutty aroma and taste, although it may be unsuitable for frying, which makes it taste burnt and bitter. Composition Sesame oil is composed of the following fatty acids: linoleic acid (41% of total), oleic acid (39%), palmitic acid (8%), stearic acid (5%) and others in small amounts. History Historically, sesame was cultivated more than 5000 years ago as a drought-tolerant crop which was able to grow where other crops failed. Sesame seeds were one of the first crops processed for oil as well as one of the earliest condiments. Sesame was cultivated during the Indus Valley civilization and was t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whale Oil
Whale oil is oil obtained from the blubber of whales. Whale oil from the bowhead whale was sometimes known as train oil, which comes from the Dutch word ''traan'' ("tears, tear" or "drop"). Sperm oil, a special kind of oil obtained from the head cavities of sperm whales, differs chemically from ordinary whale oil: it is composed mostly of liquid wax. Its properties and applications differ from those of regular whale oil, and it was sold for a higher price. Source and use Emerging industrial societies used whale oil in oil lamps and to Soap#History, make soap. In the 20th century it was made into margarine. With the commercial development of the petroleum industry and vegetable oils, the use of whale oils declined considerably from its peak in the 19th century into the 20th century. This is said to have saved whales from extinction. In the 21st century, with most countries having banned whaling, the sale and use of whale oil has practically ceased. Whale oil was obtained by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Oil
Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), precursors of certain eicosanoids that are known to reduce inflammation in the body and improve hypertriglyceridemia. There has been a great deal of controversy in recent years about the role of fish oil in cardiovascular disease, with recent meta-analyses reaching different conclusions about its potential impact. The most promising evidence supports supplementation for prevention of cardiac death. Fish oil and omega-3 fatty acids have also been studied in a wide variety of other conditions such as clinical depression, anxiety, cancer, and macular degeneration, yet their benefit in these conditions has also not been verified. The fish used as sources do not actually produce omega-3 fatty acids. Instead, the fish accumulate the acids by consuming either microalgae or prey fish that have accumulated omega-3 fatty acids. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beeswax
Beeswax (''cera alba'') is a natural wax produced by honey bees of the genus ''Apis''. The wax is formed into scales by eight wax-producing glands in the abdominal segments of worker bees, which discard it in or at the hive. The hive workers collect and use it to form cells for honey storage and larval and pupal protection within the beehive. Chemically, beeswax consists mainly of esters of fatty acids and various long-chain alcohols. Beeswax has been used since prehistory as the first plastic, as a lubricant and waterproofing agent, in lost wax casting of metals and glass, as a polish for wood and leather, for making candles, as an ingredient in cosmetics and as an artistic medium in encaustic painting. Beeswax is edible, having similarly negligible toxicity to plant waxes, and is approved for food use in most countries and in the European Union under the E number E901. Production The beeswax is formed by worker bees, which secrete it from eight wax-producing mirror glan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
