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58-580: The BIPM symbol for the tonne is t, adopted at the same time as the unit in 1879. Its use is also official for the metric ton in the United States, having been adopted by the United States National Institute of Standards and Technology (NIST). It is a symbol, not an abbreviation, and should not be followed by a period . Use of lower case is significant, and use of other letter combinations can lead to ambiguity. For example, T, MT, mT, are

116-613: A 4.35 ha (10.7-acre) site (originally 2.52 ha or 6.2 acres) granted to the Bureau by the French Government in 1876. Since 1969 the site has been considered international territory, and the BIPM has all the rights and privileges accorded to an intergovernmental organisation. This status was further clarified by the French decree No 70-820 of 9 September 1970. Several significant changes to

174-509: A large cask, or tun . A full tun, standing about a metre high, could easily weigh a tonne. See also the common German word de:Mülltonne (literal translation: garbage drum ). The spelling tonne pre-dates the introduction of the SI in 1960; it has been used with this meaning in France since 1842, when there were no metric prefixes for multiples of 10 and above, and is now used as the standard spelling for

232-586: A lesser extent to a long ton of 2,240 lb (1,016 kg), with the term tonne rarely used in speech or writing. Both terms are acceptable in Canadian English . Ton and tonne are both derived from a Germanic word in general use in the North Sea area since the Middle Ages (cf. Old English and Old Frisian tunne , Old High German and Medieval Latin tunna , German and French tonne ) to designate

290-532: A pollutant whose removal is a priority. The USEPA maintains that TNT levels in soil should not exceed 17.2 milligrams per kilogram of soil and 0.01 milligrams per litre of water. Dissolution is a measure of the rate that solid TNT in contact with water is dissolved. The relatively low aqueous solubility of TNT causes solid particles to be continuously released to the environment over extended periods of time. Studies have shown that TNT dissolves more slowly in saline water than in freshwater. However, when salinity

348-422: A pressure wave from a starter explosive, called an explosive booster . Although blocks of TNT are available in various sizes (e.g. 250 g, 500 g, 1,000 g), it is more commonly encountered in synergistic explosive blends comprising a variable percentage of TNT plus other ingredients. Examples of explosive blends containing TNT include: Upon detonation , TNT undergoes a decomposition equivalent to

406-578: Is 14.5 GJ/t (14.5 MJ/kg or 4.027 kWh/kg), which requires that the carbon in TNT fully react with atmospheric oxygen, which does not occur in the initial event. For comparison, gunpowder contains 3 MJ/kg, dynamite contains 7.5 MJ/kg, and gasoline contains 47.2 MJ/kg (though gasoline requires an oxidant , so an optimized gasoline and O 2 mixture contains 10.4 MJ/kg). Various methods can be used to detect TNT, including optical and electrochemical sensors and explosive-sniffing dogs. In 2013, researchers from

464-417: Is a chemical compound with the formula C 6 H 2 (NO 2 ) 3 CH 3 . TNT is occasionally used as a reagent in chemical synthesis , but it is best known as an explosive material with convenient handling properties. The explosive yield of TNT is considered to be the standard comparative convention of bombs and asteroid impacts. In chemistry , TNT is used to generate charge transfer salts . TNT

522-461: Is a function of their ability to associate with the mobile phase (water) and a stationary phase (soil). Materials that associate strongly with soils move slowly through soil. The association constant for TNT with soil is 2.7 to 11 L/kg of soil. This means that TNT has a one- to tenfold tendency to adhere to soil particulates than not when introduced into the soil. Hydrogen bonding and ion exchange are two suggested mechanisms of adsorption between

580-475: Is a major process that impacts the transformation of energetic compounds. The alteration of a molecule in photolysis occurs by direct absorption of light energy or by the transfer of energy from a photosensitized compound. Phototransformation of TNT "results in the formation of nitrobenzenes , benzaldehydes , azodicarboxylic acids, and nitrophenols , as a result of the oxidation of methyl groups , reduction of nitro groups , and dimer formation." Evidence of

638-737: Is a reactive molecule and is particularly prone to react with reduced components of sediments or photodegradation in the presence of sunlight. TNT is thermodynamically and kinetically capable of reacting with a wide number of components of many environmental systems. This includes wholly abiotic reactants, like hydrogen sulfide , Fe , or microbial communities, both oxic and anoxic and photochemical degradation. Soils with high clay contents or small particle sizes and high total organic carbon content have been shown to promote TNT transformation. Possible TNT transformations include reduction of one, two, or three nitro-moieties to amines and coupling of amino transformation products to form dimers . Formation of

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696-510: Is altered, TNT dissolves at the same speed. Because TNT is moderately soluble in water, it can migrate through subsurface soil, and cause groundwater contamination. Adsorption is a measure of the distribution between soluble and sediment adsorbed contaminants following attainment of equilibrium. TNT and its transformation products are known to adsorb to surface soils and sediments, where they undergo reactive transformation or remained stored. The movement or organic contaminants through soils

754-599: Is an intergovernmental organisation , through which its 59 member-states act on measurement standards in areas including chemistry , ionising radiation , physical metrology , as well as the International System of Units (SI) and Coordinated Universal Time (UTC). It is based in Saint-Cloud , near Paris , France . The organisation has been referred to as IBWM (from its name in English) in older literature. The BIPM

812-421: Is consumed by the manufacturing process, but the diluted sulfuric acid can be reconcentrated and reused. After nitration, TNT can either be purified by crystallization from an organic solvent or stabilized by a process called sulfitation, where the crude TNT is treated with aqueous sodium sulfite solution to remove less stable isomers of TNT and other undesired reaction products. The rinse water from sulfitation

870-423: Is generally saturated with the maximum amount of TNT that will dissolve in water (about 150 parts per million (ppm).) However it has an indefinite composition that depends on the exact process; in particular, it may also contain cyclotrimethylenetrinitramine (RDX) if the plant uses TNT/RDX mixtures, or HMX if TNT/HMX is used. Red water (also known as "Sellite water") is produced during the process used to purify

928-408: Is known as red water and is a significant pollutant and waste product of TNT manufacture. Control of nitrogen oxides in feed nitric acid is very important because free nitrogen dioxide can result in oxidation of the methyl group of toluene. This reaction is highly exothermic and carries with it the risk of a runaway reaction leading to an explosion. In the laboratory, 2,4,6-trinitrotoluene

986-451: Is likely to be lower "than TNT in subsurface environments where specific adsorption to clay minerals dominates the sorption process." Thus, the mobility of TNT and its transformation products are dependent on the characteristics of the sorbent. The mobility of TNT in groundwater and soil has been extrapolated from "sorption and desorption isotherm models determined with humic acids , in aquifer sediments, and soils". From these models, it

1044-515: Is listed as a possible human carcinogen , with carcinogenic effects demonstrated in animal experiments with rats, although effects upon humans so far amount to none (according to IRIS of March 15, 2000). Consumption of TNT produces red urine through the presence of breakdown products and not blood as sometimes believed. Some military testing grounds are contaminated with wastewater from munitions programs, including contamination of surface and subsurface waters which may be colored pink because of

1102-435: Is little need to distinguish between metric and other tons, and the unit is spelled either as ton or tonne with the relevant prefix attached. A metric ton unit (mtu) can mean 10 kg (22 lb) within metal trading, particularly within the United States. It traditionally referred to a metric ton of ore containing 1% (i.e. 10 kg) of metal. The following excerpt from a mining geology textbook describes its usage in

1160-403: Is one of the most commonly used explosives for military, industrial, and mining applications. TNT has been used in conjunction with hydraulic fracturing (popularly known as fracking), a process used to acquire oil and gas from shale formations. The technique involves displacing and detonating nitroglycerin in hydraulically induced fractures followed by wellbore shots using pelletized TNT. TNT

1218-604: Is overseen by the International Committee for Weights and Measures ( French : Comité international des poids et mesures, CIPM ), a committee of eighteen members that meet normally in two sessions per year, which is in turn overseen by the General Conference on Weights and Measures ( French : Conférence générale des poids et mesures, CGPM ) that meets in Paris usually once every four years, consisting of delegates of

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1276-404: Is predicted that TNT has a low retention and transports readily in the environment. Compared to other explosives, TNT has a higher association constant with soil, meaning it adheres more with soil than with water. Conversely, other explosives, such as RDX and HMX with low association constants (ranging from 0.06 to 7.3 L/kg and 0 to 1.6 L/kg respectively) can move more rapidly in water. TNT

1334-821: Is presented at each meeting of the General Conference for consideration with the BIPM budget. The final programme of work is determined by the CIPM in accordance with the budget agreed to by the CGPM. Currently, the BIPM's main work includes: The BIPM is one of the twelve member organisations of the International Network on Quality Infrastructure (INetQI), which promotes and implements QI activities in metrology , accreditation, standardisation and conformity assessment. The BIPM has an important role in maintaining accurate worldwide time of day. It combines, analyses, and averages

1392-427: Is produced by a two-step process. A nitrating mixture of concentrated nitric and sulfuric acids is used to nitrate toluene to a mixture of mono- and di-nitrotoluene isomers, with careful cooling to maintain temperature. The nitrated toluenes are then separated, washed with dilute sodium bicarbonate to remove oxides of nitrogen, and then carefully nitrated with a mixture of fuming nitric acid and sulfuric acid. TNT

1450-594: Is so insensitive that in 1910 it was exempted from the UK's Explosives Act 1875 and was not considered an explosive for the purposes of manufacture and storage. The German armed forces adopted it as a filling for artillery shells in 1902. TNT-filled armour-piercing shells would explode after they had penetrated the armour of British capital ships , whereas the British Lyddite -filled shells tended to explode upon striking armour, thus expending much of their energy outside

1508-400: Is the joule . One tonne of TNT is approximately equivalent to 4.2 gigajoules. In the petroleum industry the tonne of oil equivalent (toe) is a unit of energy : the amount of energy released by burning one tonne of crude oil , approximately 42 GJ. There are several slightly different definitions. This is ten times as much as a tonne of TNT because atmospheric oxygen is used. Like

1566-456: Is the first time this has happened since the creation of the BIPM. These changes were made official on World Metrology Day in 2019. Beginning in 1970, the BIPM began publishing the SI Brochure, a document detailing an up-to-date version of the International System of Units . As of November 2024, the most recent version of the SI Brochure was the 9th edition published in 2019. The BIPM has

1624-480: Is the mass of one cubic metre of pure water at 4 °C (39 °F). As a non-SI unit, the use of SI metric prefixes with the tonne does not fall within the SI standard. For multiples of the tonne, it is more usual to speak of thousands or millions of tonnes. Kilotonne, megatonne, and gigatonne are more usually used for the energy of nuclear explosions and other events in equivalent mass of TNT , often loosely as approximate figures. When used in this context, there

1682-466: Is used as a proxy for energy, usually of explosions (TNT is a common high explosive ). Prefixes are used: kiloton(ne), megaton(ne), gigaton(ne), especially for expressing nuclear weapon yield , based on a specific combustion energy of TNT of about 4.2  MJ / kg (or one thermochemical calorie per milligram ). Hence, 1 t TNT = approx. 4.2  GJ , 1 kt TNT = approx. 4.2  TJ , 1 Mt TNT = approx. 4.2  PJ . The SI unit of energy

1740-400: Is used as a reference point for many other explosives, including nuclear weapons, as their energy content is measured in equivalent tonnes (metric tons, t) of TNT. The energy used by NIST to define the equivalent is 4.184 GJ /t. For safety assessments, it has been stated that the detonation of TNT, depending on circumstances, can release 2.673–6.702 GJ/t. The heat of combustion however

1798-454: Is usually considered more problematic, as TNT has very low soil mobility. Red water is significantly more toxic and as such it has always been considered hazardous waste. It has traditionally been disposed of by evaporation to dryness (as the toxic components are not volatile), followed by incineration. Much research has been conducted to develop better disposal processes. Because of its suitability in construction and demolition, TNT has become

Tonne - Misplaced Pages Continue

1856-409: Is usually pronounced the same as ton ( / t ʌ n / ), but the final "e" can also be pronounced, i.e. " tunnie " ( / ˈ t ʌ n i / ). In Australia, the common and recommended pronunciation is / t ɒ n / . In the United States, metric ton is the name for this unit used and recommended by NIST; an unqualified mention of a ton typically refers to a short ton of 2,000 lb (907.2 kg) and to

1914-493: Is valued partly because of its insensitivity to shock and friction, with reduced risk of accidental detonation compared to more sensitive explosives such as nitroglycerin . TNT melts at 80 °C (176 °F), far below the temperature at which it will spontaneously detonate, allowing it to be poured or safely combined with other explosives. TNT neither absorbs nor dissolves in water, which allows it to be used effectively in wet environments. To detonate, TNT must be triggered by

1972-528: The Indian Institutes of Technology using noble-metal quantum clusters could detect TNT at the sub- zeptomolar (10 mol/m ) level. TNT is poisonous, and skin contact can cause skin irritation, causing the skin to turn a bright yellow-orange color. During the First World War , female munition workers who handled the chemical found that their skin turned bright yellow, which resulted in their acquiring

2030-525: The gram and the kilogram, the tonne gave rise to a (now obsolete) force unit of the same name, the tonne-force, equivalent to about 9.8 kilonewtons . The unit is also often called simply "tonne" or "metric ton" without identifying it as a unit of force. In contrast to the tonne as a mass unit, the tonne-force is not accepted for use with SI. International Bureau of Weights and Measures The International Bureau of Weights and Measures ( French : Bureau International des Poids et Mesures , BIPM )

2088-472: The steric hindrance of the NO 2 group in the ortho position . Research has shown that in freshwater environments, with high abundances of Ca , the adsorption of TNT and its transformation products to soils and sediments may be lower than observed in a saline environment, dominated by K and Na . Therefore, when considering the adsorption of TNT, the type of soil or sediment and the ionic composition and strength of

2146-523: The 20th century amatol , a mixture of TNT with ammonium nitrate , was a widely used military explosive. TNT can be detonated with a high velocity initiator or by efficient concussion. For many years, TNT used to be the reference point for the Figure of Insensitivity . TNT had a rating of exactly 100 on the "F of I" scale. The reference has since been changed to a more sensitive explosive called RDX , which has an F of I rating of 80. The energy density of TNT

2204-502: The BIPM have been made throughout its history during the meetings overseen by the CGPM. An example of this would be how in the 12th general council meeting (held in 1964), the BIPM's budget was increased from $ 300,000 to $ 600,000 per year. A historic moment for the BIPM occurred during the 26th CGPM in 2018. At this council, it was decided that world standard for the units of kilograms, seconds, amperes, Kelvins, moles, candelas, and meters would be redefined to reflect constants in nature. This

2262-423: The SI symbols for the tesla , megatesla, and millitesla, respectively, while Mt and mt are SI-compatible symbols for the megatonne (one teragram) and millitonne (one kilogram). If describing TNT equivalent units of energy, one megatonne of TNT is equivalent to approximately 4.184 petajoules . In English, tonne is an established spelling alternative to metric ton . In the United States and United Kingdom, tonne

2320-405: The crude TNT. It has a complex composition containing more than a dozen aromatic compounds, but the principal components are inorganic salts ( sodium sulfate , sodium sulfite , sodium nitrite and sodium nitrate ) and sulfonated nitroaromatics . Pink and red water are colorless at the time of generation; the color is produced by photolytic reactions under the influence of sunlight. Despite

2378-516: The exudated liquid into the fuze screw thread can form fire channels , increasing the risk of accidental detonation. Fuze malfunction can also result from the liquid migrating into the fuze mechanism. Calcium silicate is mixed with TNT to mitigate the tendency towards exudation. Pink water and red water are two distinct types of wastewater related to trinitrotoluene. Pink water is produced from equipment washing processes after munitions filling or demilitarization operations, and as such

Tonne - Misplaced Pages Continue

2436-623: The governments of the Member States and observers from the Associates of the CGPM. These organs are also commonly referred to by their French initialisms. The BIPM was created on 20 May 1875, following the signing of the Metre Convention , a treaty among 17 Member States (as of November 2018 there are now 59 members). It is based at the Pavillon de Breteuil in Saint-Cloud , France,

2494-432: The ground water are important factors. The association constants for TNT and its degradation products with clays have been determined. Clay minerals have a significant effect on the adsorption of energetic compounds. Soil properties, such as organic carbon content and cation exchange capacity have significant impacts on the adsorption coefficients. Additional studies have shown that the mobility of TNT degradation products

2552-478: The mandate to provide the basis for a single, coherent system of measurements throughout the world, traceable to the International System of Units (SI) . This task takes many forms, from direct dissemination of units to coordination through international comparisons of national measurement standards (as in electricity and ionising radiation). Following consultation, a draft version of the BIPM Work Programme

2610-507: The metric mass measurement in most English -speaking countries. In the United States, the unit was originally referred to using the French words millier or tonneau , but these terms are now obsolete. The British imperial and United States customary units are comparable to the tonne and the spelling of ton in English is the same, though they differ in mass. One tonne is equivalent to: A tonne

2668-529: The most widely used explosive and thus its toxicity is the most characterized and reported. Residual TNT from manufacture, storage, and use can pollute water, soil, the atmosphere , and the biosphere . The concentration of TNT in contaminated soil can reach 50 g/kg of soil, where the highest concentrations can be found on or near the surface. In September 2001, the United States Environmental Protection Agency (USEPA) declared TNT

2726-517: The names, red and pink water are not necessarily different shades; the color depends mainly on the duration of solar exposure. If exposed long enough, "pink" water may turn various shades of pink, red, rusty orange, or black. Because of the toxicity of TNT, the discharge of pink water to the environment has been prohibited in the US and many other countries for decades, but ground contamination may exist in very old plants. However, RDX and tetryl contamination

2784-400: The nickname " canary girls " or simply "canaries". People exposed to TNT over a prolonged period tend to experience anemia and abnormal liver functions. Blood and liver effects, spleen enlargement and other harmful effects on the immune system have also been found in animals that ingested or breathed trinitrotoluene. There is evidence that TNT adversely affects male fertility . TNT

2842-514: The nitro functional groups and soil colloids. The number of functional groups on TNT influences the ability to adsorb into soil. Adsorption coefficient values have been shown to increase with an increase in the number of amino groups. Thus, adsorption of the TNT decomposition product 2,4-diamino-6-nitrotoluene (2,4-DANT) was greater than that for 4-amino-2,6-dinitrotoluene (4-ADNT), which was greater than that for TNT. Lower adsorption coefficients for 2,6-DNT compared to 2,4-DNT can be attributed to

2900-465: The official atomic time standards of member nations around the world to create a single, official Coordinated Universal Time (UTC). Since its establishment, the directors of the BIPM have been: Trinitrotoluene Trinitrotoluene ( / ˌ t r aɪ ˌ n aɪ t r oʊ ˈ t ɒ lj u iː n / ), more commonly known as TNT (and more specifically 2,4,6-trinitrotoluene , and by its preferred IUPAC name 2-methyl-1,3,5-trinitrobenzene ),

2958-478: The particular case of tungsten: Tungsten concentrates are usually traded in metric tonne units (originally designating one tonne of ore containing 1% of WO 3 , today used to measure WO 3 quantities in 10 kg units. One metric tonne unit (mtu) of tungsten (VI) contains 7.93 kilograms of tungsten. In the case of uranium , MTU is sometimes used in the sense of metric ton of uranium (1,000 kg [2,200 lb]). The tonne of trinitrotoluene (TNT)

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3016-455: The photolysis of TNT has been seen due to the color change to pink of TNT-containing wastewaters when exposed to sunlight. Photolysis is more rapid in river water than in distilled water. Ultimately, photolysis affects the fate of TNT primarily in the aquatic environment but could also affect the fate of TNT in soil when the soil surface is exposed to sunlight. The ligninolytic physiological phase and manganese peroxidase system of fungi can cause

3074-409: The presence of TNT. Such contamination, called "pink water", may be difficult and expensive to remedy . TNT is prone to exudation of dinitrotoluenes and other isomers of trinitrotoluene when projectiles containing TNT are stored at higher temperatures in warmer climates. Exudation of impurities leads to formation of pores and cracks (which in turn cause increased shock sensitivity). Migration of

3132-542: The reaction plus some of the reactions and The reaction is exothermic but has a high activation energy in the gas phase (~62 kcal/mol). The condensed phases (solid or liquid) show markedly lower activation energies of roughly 35 kcal/mol due to unique bimolecular decomposition routes at elevated densities. Because of the production of carbon , TNT explosions have a sooty appearance. Because TNT has an excess of carbon, explosive mixtures with oxygen-rich compounds can yield more energy per kilogram than TNT alone. During

3190-647: The ship. The British started replacing Lyddite with TNT in 1907. The United States Navy continued filling armour-piercing shells with explosive D after some other nations had switched to TNT, but began filling naval mines , bombs , depth charges , and torpedo warheads with burster charges of crude grade B TNT with the color of brown sugar and requiring an explosive booster charge of granular crystallized grade A TNT for detonation. High-explosive shells were filled with grade A TNT, which became preferred for other uses as industrial chemical capacity became available for removing xylene and similar hydrocarbons from

3248-515: The toluene feedstock and other nitrotoluene isomer byproducts from the nitrating reactions. In industry, TNT is produced in a three-step process. First, toluene is nitrated with a mixture of sulfuric and nitric acid to produce mononitrotoluene (MNT). The MNT is separated and then renitrated to dinitrotoluene (DNT). In the final step, the DNT is nitrated to trinitrotoluene (TNT) using an anhydrous mixture of nitric acid and oleum . Nitric acid

3306-472: The two monoamino transformation products, 2-ADNT and 4-ADNT, is energetically favored, and therefore is observed in contaminated soils and ground water. The diamino products are energetically less favorable, and even less likely are the triamino products. The transformation of TNT is significantly enhanced under anaerobic conditions as well as under highly reducing conditions. TNT transformations in soils can occur both biologically and abiotically. Photolysis

3364-417: Was first synthesized in 1861 by German chemist Joseph Wilbrand and was originally used as a yellow dye. Its potential as an explosive was not recognized for three decades, mainly because it was so much less sensitive than other explosives known at the time. Its explosive properties were discovered in 1891 by another German chemist, Carl Häussermann. TNT can be safely poured when liquid into shell cases, and

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