52-415: A brickfield is an open site where bricks are made. Place names are often formed from the word. Brickfield , Brickfields , or Brickfielder may also refer to: Brickfield A brickfield is a field or other open site where bricks are made. Land may be leased by an owner to a brickmaster, by whom the manufacture of bricks may be conducted. Historically, the topsoil was typically removed and
104-420: A dichromate solution, turning the solution from orange to green (Cr (aq)). It can also reduce ferric ions to ferrous. Sulfur dioxide can react with certain 1,3- dienes in a cheletropic reaction to form cyclic sulfones . This reaction is exploited on an industrial scale for the synthesis of sulfolane , which is an important solvent in the petrochemical industry . Sulfur dioxide can bind to metal ions as
156-399: A ligand to form metal sulfur dioxide complexes , typically where the transition metal is in oxidation state 0 or +1. Many different bonding modes (geometries) are recognized, but in most cases, the ligand is monodentate, attached to the metal through sulfur, which can be either planar and pyramidal η . As a η -SO 2 (S-bonded planar) ligand sulfur dioxide functions as a Lewis base using
208-471: A byproduct in the manufacture of calcium silicate cement; CaSO 4 is heated with coke and sand in this process: Until the 1970s commercial quantities of sulfuric acid and cement were produced by this process in Whitehaven , England. Upon being mixed with shale or marl , and roasted, the sulfate liberated sulfur dioxide gas, used in sulfuric acid production, the reaction also produced calcium silicate,
260-415: A chamber where hot gases could circulate around them. Sulphur dioxide Selenium dioxide Tellurium dioxide Polonium dioxide Sulfur dioxide ( IUPAC -recommended spelling) or sulphur dioxide (traditional Commonwealth English ) is the chemical compound with the formula S O 2 . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It
312-597: A high heat of evaporation , sulfur dioxide is a candidate material for refrigerants. Before the development of chlorofluorocarbons , sulfur dioxide was used as a refrigerant in home refrigerators . Sulfur dioxide content in naturally-released geothermal gasses is measured by the Icelandic Meteorological Office as an indicator of possible volcanic activity. In the United States, the Center for Science in
364-447: A key agent in the warming of early Mars , with estimates of concentrations in the lower atmosphere as high as 100 ppm, though it only exists in trace amounts. On both Venus and Mars, as on Earth, its primary source is thought to be volcanic. The atmosphere of Io , a natural satellite of Jupiter , is 90% sulfur dioxide and trace amounts are thought to also exist in the atmosphere of Jupiter . The James Webb Space Telescope has observed
416-681: A negative inotropic effect on cardiac output function, thus effectively lowering blood pressure and myocardial oxygen consumption. The vasodilating and bronchodilating effects of sulfur dioxide are mediated via ATP-dependent calcium channels and L-type ("dihydropyridine") calcium channels. Endogenous sulfur dioxide is also a potent antiinflammatory, antioxidant and cytoprotective agent. It lowers blood pressure and slows hypertensive remodeling of blood vessels, especially thickening of their intima. It also regulates lipid metabolism. Endogenous sulfur dioxide also diminishes myocardial damage, caused by isoproterenol adrenergic hyperstimulation, and strengthens
468-452: A precursor in cement production. On a laboratory scale, the action of hot concentrated sulfuric acid on copper turnings produces sulfur dioxide. Tin also reacts with concentrated sulfuric acid but it produces tin(II) sulfate which can later be pyrolyzed at 360 °C into tin dioxide and dry sulfur dioxide. The reverse reaction occurs upon acidification: Sulfites results by the action of aqueous base on sulfur dioxide: Sulfur dioxide
520-458: A preservative for dried apricots, dried figs, and other dried fruits, owing to its antimicrobial properties and ability to prevent oxidation , and is called E 220 when used in this way in Europe. As a preservative, it maintains the colorful appearance of the fruit and prevents rotting . Historically, molasses was "sulfured" as a preservative and also to lighten its color. Treatment of dried fruit
572-556: A series of escarpments separated by low lying vales, The Cretaceous ridges are known as the North Downs and South Downs . The Downs have been cut through, with the Medway Valley being the most prominent. The Hoo peninsula is an Eocene ( Thanet sands ) ridge. The London basin is an Eocene structure composed of London Clay . All this solid geology is covered with a layer of brown structureless loam (Head), and muds deposited by
SECTION 10
#1732847875717624-423: A winery due to the risk of cork taint , a mixture of SO 2 , water, and citric acid is commonly used to clean and sanitize equipment. Ozone (O 3 ) is now used extensively for sanitizing in wineries due to its efficacy, and because it does not affect the wine or most equipment. Sulfur dioxide is also a good reductant . In the presence of water, sulfur dioxide is able to decolorize substances. Specifically, it
676-454: Is a mild but useful reducing agent . It is oxidized by halogens to give the sulfuryl halides, such as sulfuryl chloride : Sulfur dioxide is the oxidising agent in the Claus process , which is conducted on a large scale in oil refineries . Here, sulfur dioxide is reduced by hydrogen sulfide to give elemental sulfur: The sequential oxidation of sulfur dioxide followed by its hydration is used in
728-402: Is a useful reducing bleach for papers and delicate materials such as clothes. This bleaching effect normally does not last very long. Oxygen in the atmosphere reoxidizes the reduced dyes, restoring the color. In municipal wastewater treatment, sulfur dioxide is used to treat chlorinated wastewater prior to release. Sulfur dioxide reduces free and combined chlorine to chloride . Sulfur dioxide
780-504: Is also produced by roasting pyrite and other sulfide ores in air. Sulfur dioxide is the product of the burning of sulfur or of burning materials that contain sulfur: To aid combustion, liquified sulfur (140–150 °C (284–302 °F) is sprayed through an atomizing nozzle to generate fine drops of sulfur with a large surface area. The reaction is exothermic , and the combustion produces temperatures of 1,000–1,600 °C (1,830–2,910 °F). The significant amount of heat produced
832-410: Is an intermediate in the production of sulfuric acid, being converted to sulfur trioxide , and then to oleum , which is made into sulfuric acid. Sulfur dioxide for this purpose is made when sulfur combines with oxygen. The method of converting sulfur dioxide to sulfuric acid is called the contact process . Several million tons are produced annually for this purpose. Sulfur dioxide is sometimes used as
884-478: Is fairly soluble in water, and by both IR and Raman spectroscopy; the hypothetical sulfurous acid , H 2 SO 3 , is not present to any extent. However, such solutions do show spectra of the hydrogen sulfite ion, HSO 3 , by reaction with water, and it is in fact the actual reducing agent present: In the beginning of the 20th century sulfur dioxide was used in Buenos Aires as a fumigant to kill rats that carried
936-431: Is often used as a low-temperature solvent/diluent for superacids like magic acid (FSO 3 H/SbF 5 ), allowing for highly reactive species like tert -butyl cation to be observed spectroscopically at low temperature (though tertiary carbocations do react with SO 2 above about −30 °C, and even less reactive solvents like SO 2 ClF must be used at these higher temperatures). Being easily condensed and possessing
988-455: Is primarily produced for sulfuric acid manufacture (see contact process , but other processes predated that at least since 16th century ). In the United States in 1979, 23.6 million metric tons (26 million U.S. short tons) of sulfur dioxide were used in this way, compared with 150,000 metric tons (165,347 U.S. short tons) used for other purposes. Most sulfur dioxide is produced by the combustion of elemental sulfur . Some sulfur dioxide
1040-748: Is produced biologically as an intermediate in both sulfate-reducing organisms and in sulfur-oxidizing bacteria, as well. The role of sulfur dioxide in mammalian biology is not yet well understood. Sulfur dioxide blocks nerve signals from the pulmonary stretch receptors and abolishes the Hering–Breuer inflation reflex . It is considered that endogenous sulfur dioxide plays a significant physiological role in regulating cardiac and blood vessel function, and aberrant or deficient sulfur dioxide metabolism can contribute to several different cardiovascular diseases, such as arterial hypertension , atherosclerosis , pulmonary arterial hypertension , and stenocardia . It
1092-500: Is recovered by steam generation that can subsequently be converted to electricity. The combustion of hydrogen sulfide and organosulfur compounds proceeds similarly. For example: The roasting of sulfide ores such as pyrite , sphalerite , and cinnabar (mercury sulfide) also releases SO 2 : A combination of these reactions is responsible for the largest source of sulfur dioxide, volcanic eruptions. These events can release millions of tons of SO 2 . Sulfur dioxide can also be
SECTION 20
#17328478757171144-520: Is released naturally by volcanic activity and is produced as a by-product of copper extraction and the burning of sulfur - bearing fossil fuels. Sulfur dioxide is somewhat toxic to humans, although only when inhaled in relatively large quantities for a period of several minutes or more. It was known to medieval alchemists as "volatile spirit of sulfur". SO 2 is a bent molecule with C 2v symmetry point group . A valence bond theory approach considering just s and p orbitals would describe
1196-602: Is still an important compound in winemaking, and is measured in parts per million ( ppm ) in wine. It is present even in so-called unsulfurated wine at concentrations of up to 10 mg/L. It serves as an antibiotic and antioxidant , protecting wine from spoilage by bacteria and oxidation – a phenomenon that leads to the browning of the wine and a loss of cultivar specific flavors. Its antimicrobial action also helps minimize volatile acidity. Wines containing sulfur dioxide are typically labeled with "containing sulfites ". Sulfur dioxide exists in wine in free and bound forms, and
1248-429: Is the active form, while at higher pH more SO 2 is found in the inactive sulfite and bisulfite forms. The molecular SO 2 is active as an antimicrobial and antioxidant, and this is also the form which may be perceived as a pungent odor at high levels. Wines with total SO 2 concentrations below 10 ppm do not require "contains sulfites" on the label by US and EU laws. The upper limit of total SO 2 allowed in wine in
1300-648: The Yersinia pestis bacterium, which causes bubonic plague. The application was successful, and the application of this method was extended to other areas in South America. In Buenos Aires, where these apparatuses were known as Sulfurozador , but later also in Rio de Janeiro, New Orleans and San Francisco, the sulfur dioxide treatment machines were brought into the streets to enable extensive disinfection campaigns, with effective results. Sulfur dioxide or its conjugate base bisulfite
1352-471: The clay beneath was stripped and mixed with chalk and ash to make bricks . In pre-19th-century England, [i]n most areas the brickfield owner hired a brickmaster at a price per thousand bricks to superintend the site and take full responsibility for the output of the operations. He in turn contracted with moulders to temper, mould and hack the bricks. Each moulder then hired his own 'gang' of subsidiary labourers and acted as their employer. Subsequently,
1404-613: The proliferation rate of endothelial smooth muscle cells in blood vessels, via lowering the MAPK activity and activating adenylyl cyclase and protein kinase A . Smooth muscle cell proliferation is one of important mechanisms of hypertensive remodeling of blood vessels and their stenosis , so it is an important pathogenetic mechanism in arterial hypertension and atherosclerosis. Endogenous sulfur dioxide in low concentrations causes endothelium-dependent vasodilation . In higher concentrations it causes endothelium-independent vasodilation and has
1456-498: The US is 350 ppm; in the EU it is 160 ppm for red wines and 210 ppm for white and rosé wines. In low concentrations, SO 2 is mostly undetectable in wine, but at free SO 2 concentrations over 50 ppm, SO 2 becomes evident in the smell and taste of wine. SO 2 is also a very important compound in winery sanitation. Wineries and equipment must be kept clean, and because bleach cannot be used in
1508-450: The atmosphere at about 15 ppb . On other planets, sulfur dioxide can be found in various concentrations, the most significant being the atmosphere of Venus , where it is the third-most abundant atmospheric gas at 150 ppm. There, it reacts with water to form clouds of Sulfurous acid (SO2 + H2O ⇌ HSO−3+ H+), and is a key component of the planet's global atmospheric sulfur cycle and contributes to global warming . It has been implicated as
1560-409: The bonding in terms of resonance between two resonance structures. The sulfur–oxygen bond has a bond order of 1.5. There is support for this simple approach that does not invoke d orbital participation. In terms of electron-counting formalism, the sulfur atom has an oxidation state of +4 and a formal charge of +1. Sulfur dioxide is found on Earth and exists in very small concentrations in
1612-418: The bottom; it was a permanent cowl. It was filled with bricks and it allowed the hot gases to rise amongst them. The downdraught kiln was circular and about 15 ft in diameter; the hot gases rose but were deflected back down onto the bricks. This was more efficient in fuel consumption; opening ports in the roof allowed more fuel to be introduced during the firing when necessary. The Hoffmann Continuous Kiln
Brickfield (disambiguation) - Misplaced Pages Continue
1664-438: The clay layer was deeper or there was no chalk nearby. In modern times bricks are made at a brickworks . " Brickyard " can serve as a synonym of "brickfield". Brickfield or Brickfields became a common place name in southeast England . The southeast of England consists of rock strata that are more recent than most of Great Britain. It consists of a large denuded anticline , an anticline that has been eroded away leaving
1716-445: The clay mix along a six-foot tube using an Archimedes screw . The pugging process cut up the clay and made it more pliable. Pugmills were attached to a power source by lineshafts and belting. The gang consisted of a 'temperer', who cut the clay out of the washback and loaded it into a wheeled barrow, and took it to the berth where he emptied it into the hopper. The 'flatie' took the extruded clay and rolled it in sand, and handed it to
1768-421: The combinations are referred to as total SO 2 . Binding, for instance to the carbonyl group of acetaldehyde , varies with the wine in question. The free form exists in equilibrium between molecular SO 2 (as a dissolved gas) and bisulfite ion, which is in turn in equilibrium with sulfite ion. These equilibria depend on the pH of the wine. Lower pH shifts the equilibrium towards molecular (gaseous) SO 2 , which
1820-500: The field (if not too damaged ecologically) could be used for horticulture . In Kent such fields were often planted with fruit trees. Brickfields were mainly created from 1770 to 1881, when a new shaly clay was discovered at Fletton . This period coincided with the housing and railway boom in London and cheap river-transport in Thames sailing barges . Brickfields existed elsewhere, but often
1872-404: The fuel. The stack would be 32 courses high. The white brick stack was covered with rejected bricks that would help retain the heat. The fuel was known as 'rough stuff' or 'London mixture'. It was made in winter by 'scrying' sifting out the half burnt coal from domestic rubbish which had been retrieved from London by barge, then left to rot for a year or so. The finer ash was added to the slurry, and
1924-430: The green bricks to a 'hack' where they would dry off. The hack would contain 1000 bricks stacked on boards, seven courses high. These were dried for 5 weeks losing about 2 pounds (0.91 kg) in weight- these were now called 'white bricks'. The traditional method of firing bricks was to use a cowl (or clamp). A cowl was a stack of 750 'white bricks' laid on edge, and about 6 inches (15 cm) apart leaving channels for
1976-526: The kiln was reloaded with green bricks and in turn the kiln would be fired once more. There was always an empty kiln ready to take fresh green bricks so production was not interrupted by waiting for a firing to be completed. A kiln of this type is still in use at a brickworks in Rainham. The next development was the Long Continuous Kiln where bricks were stacked on flat wagons which were slowly passed through
2028-447: The larger remains used in the cowls. The cowl was fired and a 'scintler' moved outer bricks during the firing to aid airflow. The centre of the cowl fired at 900 deg C. When the firing was complete, 'sorters' dismantled the cowl. Bricks were sorted into: Later, in the larger brickfields these cowls were replaced by permanent kilns . The updraught kiln , also called a Scotch Kiln , was rectangular and open-topped with fire holes along
2080-507: The light grey sands are themselves marketable and are used in the brickmaking process, and as moulding sand for metal foundries . A field was leased from the farmer and it was 'uncallowed' (the topsoil removed). The soil had been farmed and in the Medway area it had been chalked every five years with 'fat chalk' extracted from the ' dene holes '. The head, or clay was now dug from the field in winter by workers (diggers) on piecework rates. This
2132-408: The liquid slurry was ready it was 'laundered' along wooden pipes into square washbacks, the water seeped away leaving a stiff clay mix . This process was dependent on the weather. The brickmaking was done by 'gangs' of persons who were usually a family unit. They each had a 'berth', situated in front of a washback. It contained a bench with a pugmill behind. The pugmill had an inlet hopper, and moved
Brickfield (disambiguation) - Misplaced Pages Continue
2184-420: The lone pair on S. SO 2 functions as a Lewis acids in its η -SO 2 (S-bonded pyramidal) bonding mode with metals and in its 1:1 adducts with Lewis bases such as dimethylacetamide and trimethyl amine . When bonding to Lewis bases the acid parameters of SO 2 are E A = 0.51 and E A = 1.56. The overarching, dominant use of sulfur dioxide is in the production of sulfuric acid . Sulfur dioxide
2236-416: The moulder. The moulder had a rectangular mould that he sprinkled with sand, that slotted onto a base on the bench. The clay was thrown into the mould with great force. That done, tapping the mould released the newly formed brick (green brick). They were removed from the bench by the 'off bearer' who stacked them next to the bench. A 'barrow loader' stacked 30 green bricks in a barrow. The 'pusher outer' wheeled
2288-421: The myocardial antioxidant defense reserve. Sulfur dioxide is a versatile inert solvent widely used for dissolving highly oxidizing salts. It is also used occasionally as a source of the sulfonyl group in organic synthesis . Treatment of aryl diazonium salts with sulfur dioxide and cuprous chloride yields the corresponding aryl sulfonyl chloride, for example: As a result of its very low Lewis basicity , it
2340-469: The presence of sulfur dioxide on the exoplanet WASP-39b , where it is formed through photochemistry in the planet's atmosphere. As an ice, it is thought to exist in abundance on the Galilean moons —as subliming ice or frost on the trailing hemisphere of Io , and in the crust and mantle of Europa , Ganymede , and Callisto , possibly also in liquid form and readily reacting with water. Sulfur dioxide
2392-399: The production of sulfuric acid. Sulfur dioxide dissolves in water to give " sulfurous acid ", which cannot be isolated and is instead an acidic solution of bisulfite , and possibly sulfite , ions. Sulfur dioxide is one of the few common acidic yet reducing gases. It turns moist litmus pink (being acidic), then white (due to its bleaching effect). It may be identified by bubbling it through
2444-484: The rivers. Both the head and the fluvial mud are called brickearth . Water is also needed, the rivers are saline so wells and boreholes need to be dug through the three Cretaceous chalk layers to the impermeable Gault Clay . Taking the parish of Frindsbury as a referenced example: about 1 foot (0.30 m) of acidic topsoil covers about 6 feet (1.8 m) of head, which lies on the alkaline Thanet Sands. There are five layers of sands with different properties –
2496-410: Was calculated on the volume extracted. 44 ft by 8 ft by 6 ft would make 33000 bricks. The dug clay was left exposed in heaps to weather. The washmill was usually a sunken circular pit that was brick lined. It was 4 feet (1.2 m) deep, and 15 feet (4.6 m) in diameter. A horse pulled a centrally pivoted beam with rakes that broke up the weathered clay and mixed it into a slurry. It
2548-406: Was here that the correct proportion of chalk, some river mud and even rags were added. The rags would help the combustion. Clay alone would be too brittle. The popular Kentish yellows ( London stock bricks ) used 10-17% of chalk. The surface of the porous yellow stock, reacted chemically with the sulphur dioxide in the polluted air to form an impermeable glaze as well as an attractive colour. When
2600-572: Was shown that in children with pulmonary arterial hypertension due to congenital heart diseases the level of homocysteine is higher and the level of endogenous sulfur dioxide is lower than in normal control children. Moreover, these biochemical parameters strongly correlated to the severity of pulmonary arterial hypertension. Authors considered homocysteine to be one of useful biochemical markers of disease severity and sulfur dioxide metabolism to be one of potential therapeutic targets in those patients. Endogenous sulfur dioxide also has been shown to lower
2652-399: Was the first move towards mass production. It was a series of downdraught kilns, connected in a circle or in a long rectangle. Each kiln had an access channel to the next so as soon as the one kiln was fully firing process, the waste heat would begin to fire the next. The fires would thus burn around in sequence. When the firing was complete, the bricks had time to cool before they were removed.
SECTION 50
#17328478757172704-463: Was usually done outdoors, by igniting sublimed sulfur and burning in an enclosed space with the fruits. Fruits may be sulfured by dipping them into an either sodium bisulfite , sodium sulfite or sodium metabisulfite . Sulfur dioxide was first used in winemaking by the Romans, when they discovered that burning sulfur candles inside empty wine vessels keeps them fresh and free from vinegar smell. It
#716283