Tungsten

From Wikipedia, the free encyclopedia

Tungsten,  ₇₄W

Tungsten
Pronunciation	/ˈtʌŋstən/ ​(TUNG-stən)
Alternative name	wolfram, pronounced: /ˈwʊlfrəm/ (WUUL-frəm)
Appearance	grayish white, lustrous
Standard atomic weight Ar, std(W)	183.84(1)
Tungsten in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Mo ↑ W ↓ Sg tantalum ← tungsten → rhenium
Atomic number (Z)	74
Group	group 6
Period	period 6
Block	d-block
Element category	transition metal
Electron configuration	[Xe] 4f14 5d4 6s2
Electrons per shell	2, 8, 18, 32, 12, 2
Physical properties
Phase at STP	solid
Melting point	3695 K ​(3422 °C, ​6192 °F)
Boiling point	6203 K ​(5930 °C, ​10706 °F)
Density (near r.t.)	19.3 g/cm3
when liquid (at m.p.)	17.6 g/cm3
Heat of fusion	52.31 kJ/mol
Heat of vaporization	774 kJ/mol
Molar heat capacity	24.27 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 3477 3773 4137 4579 5127 5823
Atomic properties
Oxidation states	−4, −2, −1, 0, +1, +2, +3, +4, +5, +6 (a mildly acidic oxide)
Electronegativity	Pauling scale: 2.36
Ionization energies	1st: 770 kJ/mol 2nd: 1700 kJ/mol
Atomic radius	empirical: 139 pm
Covalent radius	162±7 pm
Spectral lines of tungsten
Other properties
Natural occurrence	primordial
Crystal structure	​body-centered cubic (bcc)
Speed of sound thin rod	4620 m/s (at r.t.) (annealed)
Thermal expansion	4.5 µm/(m·K) (at 25 °C)
Thermal conductivity	173 W/(m·K)
Electrical resistivity	52.8 nΩ·m (at 20 °C)
Magnetic ordering	paramagnetic
Magnetic susceptibility	+59.0·10−6 cm3/mol (298 K)
Young's modulus	411 GPa
Shear modulus	161 GPa
Bulk modulus	310 GPa
Poisson ratio	0.28
Mohs hardness	7.5
Vickers hardness	3430–4600 MPa
Brinell hardness	2000–4000 MPa
CAS Number	7440-33-7
History
Discovery	Carl Wilhelm Scheele (1781)
First isolation	Juan José Elhuyar and Fausto Elhuyar (1783)
Named by	Torbern Bergman (1781)
Main isotopes of tungsten
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct 180W 0.12% 1.8×1018 y α 176Hf 181W syn 121.2 d ε 181Ta 182W 26.50% stable 183W 14.31% stable 184W 30.64% stable 185W syn 75.1 d β− 185Re 186W 28.43% stable

Tungsten, or wolfram, is a chemical element with symbol W and atomic number 74. The name tungsten comes from the former Swedish name for the tungstate mineral scheelite, tung sten or "heavy stone". Tungsten is a rare metal found naturally on Earth almost exclusively combined with other elements in chemical compounds rather than alone. It was identified as a new element in 1781 and first isolated as a metal in 1783. Its important ores include wolframite and scheelite.

The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all the elements discovered, melting at 3422 °C (6192 °F, 3695 K). It also has the highest boiling point, at 5930 °C (10706 °F, 6203 K). Its density is 19.3 times that of water, comparable to that of uranium and gold, and much higher (about 1.7 times) than that of lead. Polycrystalline tungsten is an intrinsically brittle and hard material (under standard conditions, when uncombined), making it difficult to work. However, pure single-crystalline tungsten is more ductile and can be cut with a hard-steel hacksaw.

Tungsten's many alloys have numerous applications, including incandescent light bulb filaments, X-ray tubes (as both the filament and target), electrodes in gas tungsten arc welding, superalloys, and radiation shielding. Tungsten's hardness and high density give it military applications in penetrating projectiles. Tungsten compounds are also often used as industrial catalysts.

Tungsten is the only metal from the third transition series that is known to occur in biomolecules that are found in a few species of bacteria and archaea. It is the heaviest element known to be essential to any living organism. However, tungsten interferes with molybdenum and copper metabolism and is somewhat toxic to more familiar forms of animal life.

Characteristics

Physical properties

In its raw form, tungsten is a hard steel-grey metal that is often brittle and hard to work. If made very pure, tungsten retains its hardness (which exceeds that of many steels), and becomes malleable enough that it can be worked easily. It is worked by forging, drawing, or extruding. Tungsten objects are also commonly formed by sintering. 

Of all metals in pure form, tungsten has the highest melting point (3422 °C, 6192 °F), lowest vapor pressure (at temperatures above 1650 °C, 3000 °F), and the highest tensile strength. Although carbon remains solid at higher temperatures than tungsten, carbon sublimes at atmospheric pressure instead of melting, so it has no melting point. Tungsten has the lowest coefficient of thermal expansion of any pure metal. The low thermal expansion and high melting point and tensile strength of tungsten originate from strong covalent bonds formed between tungsten atoms by the 5d electrons. Alloying small quantities of tungsten with steel greatly increases its toughness.

Tungsten exists in two major crystalline forms: α and β. The former has a body-centered cubic structure and is the more stable form. The structure of the β phase is called A15 cubic; it is metastable, but can coexist with the α phase at ambient conditions owing to non-equilibrium synthesis or stabilization by impurities. Contrary to the α phase which crystallizes in isometric grains, the β form exhibits a columnar habit. The α phase has one third of the electrical resistivity and a much lower superconducting transition temperature T_C relative to the β phase: ca. 0.015 K vs. 1–4 K; mixing the two phases allows obtaining intermediate T_C values. The T_C value can also be raised by alloying tungsten with another metal (e.g. 7.9 K for W-Tc). Such tungsten alloys are sometimes used in low-temperature superconducting circuits.

Isotopes

Naturally occurring tungsten consists of four stable isotopes (¹⁸²W, ¹⁸³W, ¹⁸⁴W, and ¹⁸⁶W) and one very long-lived radioisotope, ¹⁸⁰W. Theoretically, all five can decay into isotopes of element 72 (hafnium) by alpha emission, but only ¹⁸⁰W has been observed to do so, with a half-life of (1.8±0.2)×10¹⁸ years; on average, this yields about two alpha decays of ¹⁸⁰W per gram of natural tungsten per year. The other naturally occurring isotopes have not been observed to decay, constraining their half-lives to be at least 4 × 10²¹ years. 

Another 30 artificial radioisotopes of tungsten have been characterized, the most stable of which are ¹⁸¹W with a half-life of 121.2 days, ¹⁸⁵W with a half-life of 75.1 days, ¹⁸⁸W with a half-life of 69.4 days, ¹⁷⁸W with a half-life of 21.6 days, and ¹⁸⁷W with a half-life of 23.72 h. All of the remaining radioactive isotopes have half-lives of less than 3 hours, and most of these have half-lives below 8 minutes. Tungsten also has 11 meta states, with the most stable being ^179mW (t_1/2 6.4 minutes).

Chemical properties

Elemental tungsten resists attack by oxygen, acids, and alkalis.

The most common formal oxidation state of tungsten is +6, but it exhibits all oxidation states from −2 to +6. Tungsten typically combines with oxygen to form the yellow tungstic oxide, WO₃, which dissolves in aqueous alkaline solutions to form tungstate ions, WO²⁻
₄. 

Tungsten carbides (W₂C and WC) are produced by heating powdered tungsten with carbon. W₂C is resistant to chemical attack, although it reacts strongly with chlorine to form tungsten hexachloride (WCl₆).

In aqueous solution, tungstate gives the heteropoly acids and polyoxometalate anions under neutral and acidic conditions. As tungstate is progressively treated with acid, it first yields the soluble, metastable "paratungstate A" anion, W
₇O^6–
₂₄, which over time converts to the less soluble "paratungstate B" anion, H
₂W
₁₂O^10–
₄₂. Further acidification produces the very soluble metatungstate anion, H
₂W
₁₂O^6–
₄₀, after which equilibrium is reached. The metatungstate ion exists as a symmetric cluster of twelve tungsten-oxygen octahedra known as the Keggin anion. Many other polyoxometalate anions exist as metastable species. The inclusion of a different atom such as phosphorus in place of the two central hydrogens in metatungstate produces a wide variety of heteropoly acids, such as phosphotungstic acid H₃PW₁₂O₄₀. 

Tungsten trioxide can form intercalation compounds with alkali metals. These are known as bronzes; an example is sodium tungsten bronze.

History

In 1781, Carl Wilhelm Scheele discovered that a new acid, tungstic acid, could be made from scheelite (at the time named tungsten). Scheele and Torbern Bergman suggested that it might be possible to obtain a new metal by reducing this acid. In 1783, José and Fausto Elhuyar found an acid made from wolframite that was identical to tungstic acid. Later that year, at the Royal Basque Society in the town of Bergara, Spain, the brothers succeeded in isolating tungsten by reduction of this acid with charcoal, and they are credited with the discovery of the element (they called it "wolfram" or "volfram").

The strategic value of tungsten came to notice in the early 20th century. British authorities acted in 1912 to free the Carrock mine from the German owned Cumbrian Mining Company and, during World War I, restrict German access elsewhere. In World War II, tungsten played a more significant role in background political dealings. Portugal, as the main European source of the element, was put under pressure from both sides, because of its deposits of wolframite ore at Panasqueira. Tungsten's desirable properties such as resistance to high temperatures, its hardness and density, and its strengthening of alloys made it an important raw material for the arms industry, both as a constituent of weapons and equipment and employed in production itself, e.g., in tungsten carbide cutting tools for machining steel.

Etymology

The name "tungsten" (from the Swedish tung sten, "heavy stone") is used in English, French, and many other languages as the name of the element, but not in the Nordic countries. "Tungsten" was the old Swedish name for the mineral scheelite. "Wolfram" (or "volfram") is used in most European (especially Germanic, Spanish and Slavic) languages and is derived from the mineral wolframite, which is the origin of the chemical symbol W. The name "wolframite" is derived from German "wolf rahm" ("wolf soot" or "wolf cream"), the name given to tungsten by Johan Gottschalk Wallerius in 1747. This, in turn, derives from Latin "lupi spuma", the name Georg Agricola used for the element in 1546, which translates into English as "wolf's froth" and is a reference to the large amounts of tin consumed by the mineral during its extraction.

Occurrence

Wolframite mineral, with a scale in cm.

 

Tungsten is found mainly in the minerals wolframite (iron–manganese tungstate (Fe,Mn)WO₄, which is a solid solution of the two minerals ferberite FeWO₄, and hübnerite MnWO₄) and scheelite (calcium tungstate (CaWO₄). Other tungsten minerals range in their level of abundance from moderate to very rare, and have almost no economical value.

Chemical compounds

Structure of W₆Cl₁₈ ("tungsten trichloride").

 

Tungsten forms chemical compounds in oxidation states from -II to VI. Higher oxidation states, always as oxides, are relevant to its terrestrial occurrence and its biological roles, mid-level oxidation states are often associated with metal clusters, and very low oxidation states are typically associated with CO complexes. The chemistries of tungsten and molybdenum show strong similarities to each other, as well as contrasts with their lighter congener, chromium. The relative rarity of tungsten(III), for example, contrasts with the pervasiveness of the chromium(III) compounds. The highest oxidation state is seen in tungsten(VI) oxide (WO₃). Molybdenum trioxide, which is volatile at high temperatures, is the precursor to virtually all other Mo compounds as well as alloys. Tungsten(VI) oxide is soluble in aqueous base, forming tungstate (WO₄²⁻). This oxyanion condenses at lower pH values, forming polyoxotungstates.

The broad range of oxidation states of tungsten is reflected in it various chlorides:

• Tungsten(II) chloride, which exists as the hexamer W₆Cl₁₂
• Tungsten(III) chloride, which exists as the hexamer W₆Cl₁₈
• Tungsten(IV) chloride, WCl₄, a black solid, which adopts a polymeric structure.
• Tungsten(V) chloride WCl₅, a black solid which adopts a dimeric structure.
• Tungsten(VI) chloride WCl₆, which contrasts with the instability of MoCl₆.

Organotungsten compounds are numerous and also span a range of oxidation states. Notable examples include the trigonal prismatic W(CH₃)₆ and octahedral W(CO)₆.

Production

Tungsten mining in Rwanda forms an important part of the country's economy.

 

The world's reserves of tungsten are 3,200,000 tonnes; they are mostly located in China (1,800,000 t), Canada (290,000 t), Russia (160,000 t), Vietnam (95,000 t) and Bolivia. As of 2017, China, Vietnam and Russia are the leading suppliers with 79,000, 7,200 and 3,100 tonnes, respectively. Canada had ceased production in late 2015 due the closure of its sole tungsten mine. Meanwhile Vietnam had significantly increased its output in the 2010s, owing to the major optimization of its domestic refining operations, and overtook Russia and Bolivia.

China remains the world's leader not only in production, but also in export and consumption of tungsten products. The tungsten production gradually increases outside China because of the rising demand. Meanwhile its supply by China is strictly regulated by the Chinese Government, which fights illegal mining and excessive pollution originating from mining and refining processes.

Tungsten is considered to be a conflict mineral due to the unethical mining practices observed in the Democratic Republic of the Congo.

There is a large deposit of tungsten ore on the edge of Dartmoor in the United Kingdom, which was exploited during World War I and World War II as the Hemerdon Mine. Following increases in tungsten prices, this mine was reactivated in 2014, but ceased activities in 2018.

Tungsten is extracted from its ores in several stages. The ore is eventually converted to tungsten(VI) oxide (WO₃), which is heated with hydrogen or carbon to produce powdered tungsten. Because of tungsten's high melting point, it is not commercially feasible to cast tungsten ingots. Instead, powdered tungsten is mixed with small amounts of powdered nickel or other metals, and sintered. During the sintering process, the nickel diffuses into the tungsten, producing an alloy.

Tungsten can also be extracted by hydrogen reduction of WF₆:

WF₆ + 3 H₂ → W + 6 HF

or pyrolytic decomposition:

WF₆ → W + 3 F₂ (ΔH_r = +)

Tungsten is not traded as a futures contract and cannot be tracked on exchanges like the London Metal Exchange. The prices are usually quoted for tungsten concentrate or WO₃.

Applications

Close-up of a tungsten filament inside a halogen lamp

 

Tungsten carbide ring (jewelry)

 

Approximately half of the tungsten is consumed for the production of hard materials – namely tungsten carbide – with the remaining major use being in alloys and steels. Less than 10% is used in other chemical compounds. Because of the high ductile-brittle transition temperature of tungsten, its products are conventionally manufactured through powder metallurgy, spark plasma sintering, chemical vapor deposition, hot isostatic pressing, and thermoplastic routes. A more flexible manufacturing alternative is selective laser melting, which allows creating complex three-dimensional shapes.

Hard materials

Tungsten is mainly used in the production of hard materials based on tungsten carbide, one of the hardest carbides, with a melting point of 2770 °C. WC is an efficient electrical conductor, but W₂C is less so. WC is used to make wear-resistant abrasives, and "carbide" cutting tools such as knives, drills, circular saws, milling and turning tools used by the metalworking, woodworking, mining, petroleum and construction industries. Carbide tooling is actually a ceramic/metal composite, where metallic cobalt acts as a binding (matrix) material to hold the WC particles in place. This type of industrial use accounts for about 60% of current tungsten consumption.

The jewelry industry makes rings of sintered tungsten carbide, tungsten carbide/metal composites, and also metallic tungsten. WC/metal composite rings use nickel as the metal matrix in place of cobalt because it takes a higher luster when polished. Sometimes manufacturers or retailers refer to tungsten carbide as a metal, but it is a ceramic. Because of tungsten carbide's hardness, rings made of this material are extremely abrasion resistant, and will hold a burnished finish longer than rings made of metallic tungsten. Tungsten carbide rings are brittle, however, and may crack under a sharp blow.

Alloys

The hardness and density of tungsten are applied in obtaining heavy metal alloys. A good example is high speed steel, which can contain as much as 18% tungsten. Tungsten's high melting point makes tungsten a good material for applications like rocket nozzles, for example in the UGM-27 Polaris submarine-launched ballistic missile. Tungsten alloys are used in a wide range of different applications, including the aerospace and automotive industries and radiation shielding. Superalloys containing tungsten, such as Hastelloy and Stellite, are used in turbine blades and wear-resistant parts and coatings. 

Quenched (martensitic) tungsten steel (approx. 5.5% to 7.0% W with 0.5% to 0.7% C) was used for making hard permanent magnets, due to its high remanence and coercivity, as noted by John Hopkinson (1849–1898) as early as 1886. The magnetic properties of a metal or an alloy are very sensitive to microstructure. For example, while the element tungsten is not ferromagnetic (but iron is), when present in steel in these proportions, it stabilizes the martensite phase, which has an enhanced ferromagnetism, as compared to the ferrite (iron) phase, due to its greater resistance to magnetic domain wall motion.

Tungsten's heat resistance makes it useful in arc welding applications when combined with another highly-conductive metal such as silver or copper. The silver or copper provides the necessary conductivity and the tungsten allows the welding rod to withstand the high temperatures of the arc welding environment.

Armaments

Tungsten, usually alloyed with nickel and iron or cobalt to form heavy alloys, is used in kinetic energy penetrators as an alternative to depleted uranium, in applications where uranium's radioactivity is problematic even in depleted form, or where uranium's additional pyrophoric properties are not desired (for example, in ordinary small arms bullets designed to penetrate body armor). Similarly, tungsten alloys have also been used in cannon shells, grenades and missiles, to create supersonic shrapnel. Germany used tungsten during World War II to produce shells for anti-tank gun designs using the Gerlich squeeze bore principle to achieve very high muzzle velocity and enhanced armor penetration from comparatively small caliber and light weight field artillery. The weapons were highly effective but a shortage of tungsten used in the shell core limited that effectiveness.

Tungsten has also been used in Dense Inert Metal Explosives, which use it as dense powder to reduce collateral damage while increasing the lethality of explosives within a small radius.

Chemical applications

Tungsten(IV) sulfide is a high temperature lubricant and is a component of catalysts for hydrodesulfurization. MoS₂ is more commonly used for such applications.

Tungsten oxides are used in ceramic glazes and calcium/magnesium tungstates are used widely in fluorescent lighting. Crystal tungstates are used as scintillation detectors in nuclear physics and nuclear medicine. Other salts that contain tungsten are used in the chemical and tanning industries. Tungsten oxide (WO₃) is incorporated into selective catalytic reduction (SCR) catalysts found in coal-fired power plants. These catalysts convert nitrogen oxides (NO_x) to nitrogen (N₂) and water (H₂O) using ammonia (NH₃). The tungsten oxide helps with the physical strength of the catalyst and extends catalyst life.

Niche uses

Applications requiring its high density include weights, counterweights, ballast keels for yachts, tail ballast for commercial aircraft, and as ballast in race cars for NASCAR and Formula One. In Formula One nowadays, a much more advanced material is utilized: a tungsten alloy trademarked, Densamet. Depleted uranium is also used for these purposes, due to similarly high density. Seventy-five-kg blocks of tungsten were used as "cruise balance mass devices" on the entry vehicle portion of the 2012 Mars Science Laboratory spacecraft. It is an ideal material to use as a dolly for riveting, where the mass necessary for good results can be achieved in a compact bar. High-density alloys of tungsten with nickel, copper or iron are used in high-quality darts (to allow for a smaller diameter and thus tighter groupings) or for fishing lures (tungsten beads allow the fly to sink rapidly). Tungsten has seen use recently in nozzles for 3D printing; the high wear resistance and thermal conductivity of tungsten carbide improves the printing of abrasive filaments. Some cello C strings are wound with tungsten. The extra density gives this string more projection and often cellists will buy just this string and use it with three strings from a different set. Tungsten is used as an absorber on the electron telescope on the Cosmic Ray System of the two Voyager spacecraft.

Sodium tungstate is used in Folin-Ciocalteu's reagent, a mixture of different chemicals used in the "Lowry Assay" for protein content analysis.

Gold substitution

Its density, similar to that of gold, allows tungsten to be used in jewelry as an alternative to gold or platinum. Metallic tungsten is hypoallergenic, and is harder than gold alloys (though not as hard as tungsten carbide), making it useful for rings that will resist scratching, especially in designs with a brushed finish. 

Because the density is so similar to that of gold (tungsten is only 0.36% less dense), and its price of the order of one-thousandth, tungsten can also be used in counterfeiting of gold bars, such as by plating a tungsten bar with gold, which has been observed since the 1980s, or taking an existing gold bar, drilling holes, and replacing the removed gold with tungsten rods. The densities are not exactly the same, and other properties of gold and tungsten differ, but gold-plated tungsten will pass superficial tests.

Gold-plated tungsten is available commercially from China (the main source of tungsten), both in jewelry and as bars.

Electronics

Because it retains its strength at high temperatures and has a high melting point, elemental tungsten is used in many high-temperature applications, such as light bulb, cathode-ray tube, and vacuum tube filaments, heating elements, and rocket engine nozzles. Its high melting point also makes tungsten suitable for aerospace and high-temperature uses such as electrical, heating, and welding applications, notably in the gas tungsten arc welding process (also called tungsten inert gas (TIG) welding). 

Tungsten electrode used in a gas tungsten arc welding torch

 

Because of its conductive properties and relative chemical inertness, tungsten is also used in electrodes, and in the emitter tips in electron-beam instruments that use field emission guns, such as electron microscopes. In electronics, tungsten is used as an interconnect material in integrated circuits, between the silicon dioxide dielectric material and the transistors. It is used in metallic films, which replace the wiring used in conventional electronics with a coat of tungsten (or molybdenum) on silicon.

The electronic structure of tungsten makes it one of the main sources for X-ray targets, and also for shielding from high-energy radiations (such as in the radiopharmaceutical industry for shielding radioactive samples of FDG). It is also used in gamma imaging as a material from which coded apertures are made, due to its excellent shielding properties. Tungsten powder is used as a filler material in plastic composites, which are used as a nontoxic substitute for lead in bullets, shot, and radiation shields. Since this element's thermal expansion is similar to borosilicate glass, it is used for making glass-to-metal seals. In addition to its high melting point, when tungsten is doped with potassium, it leads to an increased shape stability (compared to non-doped tungsten). This ensures that the filament does not sag, and no undesired changes occur.

Nanowires

Through top-down nanofabrication processes, tungsten nanowires have been fabricated and studied since 2002. Due to a particularly high surface to volume ratio, the formation of a surface oxide layer and the single crystal nature of such material, the mechanical properties differ fundamentally from those of bulk tungsten. Such tungsten nanowires have potential applications in nanoelectronics and importantly as pH probes and gas sensors. In similarity to silicon nanowires, tungsten nanowires are frequently produced from a bulk tungsten precursor followed by a thermal oxidation step to control morphology in terms of length and aspect ratio. Using the Deal–Grove model it is possible to predict the oxidation kinetics of nanowires fabricated through such thermal oxidation processing.

Biological role

Tungsten, at atomic number Z = 74, is the heaviest element known to be biologically functional. It is used by some bacteria and archaea, but not in eukaryotes. For example, enzymes called oxidoreductases use tungsten similarly to molybdenum by using it in a tungsten-pterin complex with molybdopterin (molybdopterin, despite its name, does not contain molybdenum, but may complex with either molybdenum or tungsten in use by living organisms). Tungsten-using enzymes typically reduce carboxylic acids to aldehydes. The tungsten oxidoreductases may also catalyse oxidations. The first tungsten-requiring enzyme to be discovered also requires selenium, and in this case the tungsten-selenium pair may function analogously to the molybdenum-sulfur pairing of some molybdenum cofactor-requiring enzymes. One of the enzymes in the oxidoreductase family which sometimes employ tungsten (bacterial formate dehydrogenase H) is known to use a selenium-molybdenum version of molybdopterin. Acetylene hydratase is an unusual metalloenzyme in that it catalyzes a hydration reaction. Two reaction mechanisms have been proposed, in one of which there is a direct interaction between the tungsten atom and the C≡C triple bond. Although a tungsten-containing xanthine dehydrogenase from bacteria has been found to contain tungsten-molydopterin and also non-protein bound selenium, a tungsten-selenium molybdopterin complex has not been definitively described.

In soil, tungsten metal oxidizes to the tungstate anion. It can be selectively or non-selectively imported by some prokaryotic organisms and may substitute for molybdate in certain enzymes. Its effect on the action of these enzymes is in some cases inhibitory and in others positive. The soil's chemistry determines how the tungsten polymerizes; alkaline soils cause monomeric tungstates; acidic soils cause polymeric tungstates.

Sodium tungstate and lead have been studied for their effect on earthworms. Lead was found to be lethal at low levels and sodium tungstate was much less toxic, but the tungstate completely inhibited their reproductive ability.

Tungsten has been studied as a biological copper metabolic antagonist, in a role similar to the action of molybdenum. It has been found that tetrathiotungstates may be used as biological copper chelation chemicals, similar to the tetrathiomolybdates.

In archaea

Tungsten is essential for some archaea. The following tungsten-utilizing enzymes are known:

• Aldehyde ferredoxin oxidoreductase (AOR) in Thermococcus strain ES-1
• Formaldehyde ferredoxin oxidoreductase (FOR) in Thermococcus litoralis
• Glyceraldehyde-3-phosphate ferredoxin oxidoreductase (GAPOR) in Pyrococcus furiosus

A wtp system is known to selectively transport tungsten in archaea:

• WtpA is tungsten-binding protein of ABC family of transporters
• WptB is a permease
• WtpC is ATPase

Health factors

Because tungsten is a rare metal and its compounds are generally inert, the effects of tungsten on the environment are limited. The abundance of tungsten in the Earth's crust is thought to be about 1.5 parts per million. It is one of the more rare elements. 

It was at first believed to be relatively inert and an only slightly toxic metal, but beginning in the year 2000, the risk presented by tungsten alloys, its dusts and particulates to induce cancer and several other adverse effects in animals as well as humans has been highlighted from in vitro and in vivo experiments. The median lethal dose LD₅₀ depends strongly on the animal and the method of administration and varies between 59 mg/kg (intravenous, rabbits) and 5000 mg/kg (tungsten metal powder, intraperitoneal, rats).

People can be exposed to tungsten in the workplace by breathing it in, swallowing it, skin contact, and eye contact. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 5 mg/m³ over an 8-hour workday and a short term limit of 10 mg/m³.

Gross National Happiness

From Wikipedia, the free encyclopedia

Slogan about Gross National Happiness in Thimphu's School of Traditional Arts.

 

Gross National Happiness (also known by the acronym: GNH) is a philosophy that guides the government of Bhutan. It includes an index which is used to measure the collective happiness and well-being of a population. Gross National Happiness is instituted as the goal of the government of Bhutan in the Constitution of Bhutan, enacted on 18 July 2008.

The term Gross National Happiness was coined in 1972 during an interview by a British journalist for the Financial Times at Bombay airport when the then king of Bhutan, Jigme Singye Wangchuck, said "Gross National Happiness is more important than Gross National Product."

In 2011, The UN General Assembly passed Resolution "Happiness: towards a holistic approach to development" urging member nations to follow the example of Bhutan and measure happiness and well-being and calling happiness a "fundamental human goal."

In 2012, Bhutan's Prime Minister Jigme Thinley and the Secretary General Ban Ki-Moon of the United Nations convened the High Level Meeting: Well-being and Happiness: Defining a New Economic Paradigm to encourage the spread of Bhutan's GNH philosophy. At the High Level meeting, the first World Happiness Report was issued. Shortly after the High Level meeting, 20 March was declared to be International Day of Happiness by the UN in 2012 with resolution 66/28.

Bhutan's Prime Minister Tshering Tobgay proclaimed a preference for focus on more concrete goals instead of promoting GNH when he took office, but subsequently has protected the GNH of his country and promoted the concept internationally. Other Bhutanese officials also promote the spread of GNH at the UN and internationally.

GNH Defined

GNH is distinguishable from Gross Domestic Product by valuing collective happiness as the goal of governance, by emphasizing harmony with nature and traditional values as expressed in the 9 domains of happiness and 4 pillars of GNH. The four pillars of GNH's are 1) sustainable and equitable socio-economic development; 2) environmental conservation; 3) preservation and promotion of culture; and 4) good governance. The nine domains of GNH are psychological well-being, health, time use, education, cultural diversity and resilience, good governance, community vitality, ecological diversity and resilience, and living standards. Each domain is composed of subjective (survey-based) and objective indicators. The domains weigh equally but the indicators within each domain differ by weight.

Implementation of GNH in Bhutan

The Gross National Happiness Commission is charged with implementing GNH in Bhutan. The GNH Commission is composed of the Secretaries each of the ministries of the government, the Prime Minister, and the Secretary of the GNH Commission. The GNH Commission's tasks include conceiving and implementing the nation's 5-year plan and promulgating policies. The GNH Index is used to measure the happiness and well-being of Bhutan's population. A GNH Policy Screening Tool and a GNH Project Screening Tool is used by the GNH commission to determine whether to pass policies or implement projects. The GNH Screening tools used by the Bhutanese GNH Commission for anticipating the impact of policy initiatives upon the levels of GNH in Bhutan.

In 2008, the first GNH survey was conducted. It was followed by a second one in 2010. The third nationwide survey was conducted in 2015. The GNH survey covers all twenty districts (Dzonkhag) and results are reported for varying demographic factors such as gender, age, abode, and occupation. The first GNH surveys consisted of long questionnaires that polled the citizens about living conditions and religious behavior, including questions about the times a person prayed in a day and other Karma indicators. It took several hours to complete one questionnaire. Later rounds of the GNH Index were shortened, but the survey retained the religious behavioral indicators.

The Bhutan GNH Index was developed by the Centre for Bhutan Studies with the help of the researchers from Oxford University researchers to help measure the progress of Bhutanese society. The Index function was based on Alkire & Foster method of 2011. After the creation of the national GNH Index, the government used the metric to measure national progress and inform policy.

The Bhutan GNH Index is considered to measure societal progress similarly to other models such as the Gross National Well-being of 2005, the OECD Better Life Index of 2011, and SPI Social Progress Index of 2013. One distinguishing feature of Bhutan GNH Index from the other models is that the other models are designed for secular governments and do not include religious behavior measurement components. 

The data is used to compare the happiness between different groups of citizens, and changes over time.

According to the World Happiness Report 2018, Bhutan is 97th out of 156 countries.

Spread of GNH Outside of Bhutan

In Victoria, British Columbia, Canada, a shortened version of Bhutan's GNH survey was used by the local government, local foundations and governmental agencies under the leadership of Martha and Michael Pennock to assess the population of Victoria.

In the state of São Paulo, Brazil, Susan Andrews, through her organization Future Vision Ecological Park, used a version of Bhutan's GNH at a community level in some cities.

In Seattle, Washington, United States, a version of the GNH Index was used by the Seattle City Council and Sustainable Seattle to assess the happiness and well-being of the Seattle Area population. Other cities and areas in North America, including Eau Claire, Wisconsin, Creston, British Columbia and the U.S. state of Vermont, also used a version of the GNH Index.

At the University of Oregon, United States, a behavioral model of GNH based on the use of positive and negative words in social network status updates was developed by Adam Kramer.

In 2016, Thailand launched its own GNH center. The former king of Thailand, Bhumibol Adulyadej, was a close friend of King Jigme Singye Wangchuck, and conceived the similar philosophy of Sufficiency Economy.

In the Philippines, the concept of GNH has been lauded by various personalities, notably Philippine senator and UN Global Champion for Resilience Loren Legarda, and former environment minister Gina Lopez. Bills have been filed in the Philippine Senate and House of Representatives in support of Gross National Happiness in the Philippines. Additionally, Executive Director of Bhutan’s GNH Center, Dr. Saamdu Chetri, has been invited by high-level officials in the Philippines for a GNH Forum.

Many other cities and governments have undertaken efforts to measure happiness and well-being (also termed "Beyond GDP") since the High Level Meeting in 2012, but have not used versions of Bhutan's GNH index. Among these include the national governments of the United Kingdom's Office of National Statistics and the United Arab Emirates, and cities including Somerville, Massachusetts, United States, and Bristol, United Kingdom. Also a number of companies which are implementing sustainability practices in business have been inspired by GNH.

Gross National Happiness is also promoted in the United States by a nonprofit organization, Gross National Happiness USA. Headquartered in Vermont, GNHUSA is a 501c(3) tax-exempt non-profit organization with a mission to increase personal happiness and the collective wellbeing by changing how the United States measure their progress and success. GNHUSA was founded after Linda Wheatley of Montpelier, Vermont, attended the 2008 Annual Gross National Happiness Research Conference in Thimphu, Bhutan. Wheatley returned to Vermont determined to introduce the little-known GNH concepts to the general public in the U.S. After establishing the nonprofit in the spring of 2009, representatives of the group attended the fifth international GNH research conference in Brazil in November 2009 and, in June 2010, hosted the first US-based conference on Gross National Happiness and other alternative indicators, at Champlain College in Burlington, Vermont. In May 2012, GNHUSA with co-sponsors organized Measure What Matters, a conference building a collaborative of data experts in Vermont. The state of Vermont's Governor declared April 13 (President Jefferson’s birthday) “Pursuit of Happiness Day,” and became the first state to pass legislation enabling development of alternative indicators and to assist in making policy. GNHUSA collaborates with the Vermont Data Center to perform a periodic study of well-being in the state, as a pilot for other states and municipalities. The organization also collaborates closely with the Happiness Alliance in collecting online GNH data, based on the domain of happiness developed by Bhutan. In 2017, GNHUSA initiated the process of establishing chapters in all 50 states to work with local governments and institutions on well-being initiatives, beginning with Wisconsin and North Carolina. The organization also promotes the U.N.-designated International Happiness Day (March 20) as an opportunity to discuss the concepts of well-being with others at Happiness Dinners across the country.

From August 25, 2012 to the present, GNHUSA has been carrying out a nationwide action research project, The Happiness Walk, carried out by GNHUSA board members and supporters. On the first leg, two GNHUSA board members walked 594 miles, from Vermont to Washington DC; the Walk most recently completed a leg from Santa Monica, CA to the Bay Area, with a side trip to Hawaii, and resumed March 1, 2018, walking from Petaluma CA to Seattle, Washington, on the 13th leg of the journey. Along the way, Walkers perform audio and video interviews and collect survey responses, introducing the concept of GNH and amassing data that will assist them in tailoring the GNH domains and indicators to American culture. GNHUSA also posts and promotes a Charter for Happiness which, as of May 7, 2018, has 469 signatories.

Criticism

GNH has been described by critics as a propaganda tool used by the Bhutanese government to distract from ethnic cleansing and human rights abuses it has committed.

Bhutanese democratic government began in 2008. Before that time the government practiced massive ethnic cleansing of non-Buddhist population of ethnic Nepalese of Hindu faith in the name of GNH cultural preservation. The NGO Human Rights Watch documented the events. According to Human Rights Watch, "Over 100,000 or 1/6 of the population of Bhutan of Nepalese origin and Hindu faith were expelled from the country because they would not integrate with Bhutan’s Buddhist culture." The Refugee Council of Australia stated that "it is extraordinary and shocking that a nation can get away with expelling one sixth of its people and somehow keep its international reputation largely intact. The Government of Bhutan should be known not for Gross National Happiness but for Gross National Hypocrisy."

Some researchers state that Bhutan's GNH philosophy “has evolved over the last decade through the contribution of western and local scholars to a version that is more democratic and open. Therefore, probably, the more accurate historical reference is to mention the coining of the GNH phrase as a key event, but not the Bhutan GNH philosophy, because the philosophy as understood by western scholars is different from the philosophy used by the King at the time.” Other viewpoints are that GNH is a process of development and learning, rather than an objective norm or absolute end point. Bhutan aspires to enhance the happiness of its people and GNH serves as a measurement tool for realizing that aspiration.

Other criticism focuses on the standard of living in Bhutan. In an article written in 2004 in the Economist magazine, “The Himalayan kingdom of Bhutan is not in fact an idyll in a fairy tale. It is home to perhaps 900,000 people most of whom live in grinding poverty." Other criticism of GNH cites "increasing levels of political corruption, the rapid spread of diseases such as AIDS and tuberculosis, gang violence, abuses against women and ethnic minorities, shortages in food/medicine, and economic woes."

Buddhist economics

From Wikipedia, the free encyclopedia

Slogan in Bhutan about gross national happiness in Thimphu's School of Traditional Arts.

 

Buddhist economics is a spiritual and philosophical approach to the study of economics. It examines the psychology of the human mind and the emotions that direct economic activity, in particular concepts such as anxiety, aspirations and self-actualization principles. In the view of its proponents, Buddhist economics aims to clear the confusion about what is harmful and what is beneficial in the range of human activities involving the production and consumption of goods and services, ultimately trying to make human beings ethically mature. The ideology's stated purpose is to "find a middle way between a purely mundane society and an immobile, conventional society."

Sri Lankan economist Neville Karunatilake wrote that: "A Buddhist economic system has its foundations in the development of a co-operative and harmonious effort in group living. Selfishness and acquisitive pursuits have to be eliminated by developing man himself." Karunatilake sees Buddhist economic principles as exemplified in the rule of the Buddhist king Ashoka. 

Bhutan's King Jigme Singye Wangchuck and its government have promoted the concept of "gross national happiness" (GNH) since 1972, based on Buddhist spiritual values, as a counter to gauging a nation's development by gross domestic product (GDP). This represents a commitment to building an economy that would serve Bhutan's culture based on Buddhist spiritual values instead of material development, such as being gauged by only GDP.

U.S. economics professor Clair Brown sets up a Buddhist economics framework that integrates Amartya Sen's capability approach with shared prosperity and sustainability. In her Buddhist economics model, valuation of economic performance is based on how well the economy delivers a high quality of life to everyone while it protects the environment. In addition to domestic output (or consumption), measuring economic performance includes equity, sustainability, and activities that create a meaningful life. A person’s well-being depends on cultivation of inner (spiritual) wealth even more than outer (material) wealth.

Buddhist economics holds that truly rational decisions can only be made when we understand what creates irrationality. When people understand what constitutes desire, they realize that all the wealth in the world cannot satisfy it. When people understand the universality of fear, they become more compassionate to all beings. Thus, this spiritual approach to economics doesn't rely on theories and models, but on the essential forces of acumen, empathy, and restraint. From the perspective of a Buddhist, economics and other streams of knowledge cannot be separated. Economics is a single component of a combined effort to fix the problems of humanity and Buddhist economics works with it to reach a common goal of societal, individual, and environmental sufficiency.

History

Buddhist ethics was first applied to the running of a state's economy during the rule of the Indian Buddhist emperor Ashoka (c. 268 to 232 BCE). The reign of Ashoka is famous for an extensive philanthropic and public works program, which built hospitals, hostels, parks, and nature preserves.

The term "Buddhist economics" was coined by E. F. Schumacher in 1955, when he travelled to Burma as an economic consultant for Prime Minister U Nu. The term was used in his essay named "Buddhist Economics", which was first published in 1966 in Asia: A Handbook, and republished in his influential collection Small Is Beautiful (1973). The term is currently used by followers of Schumacher and by Theravada Buddhist writers, such as Prayudh Payutto, Padmasiri De Silva, and Luang Por Dattajivo. 

The 1st Conference of the Buddhist Economics Research Platform was held in Budapest, Hungary from 23–24 August 2007. The second conference was held at Ubon Ratchathani University, Thailand from 9–11 April 2009.

General views on economics

Unlike traditional economics, Buddhist economics considers stages after the consumption of a product, investigating how trends affect the three intertwined aspects of human existence: the individual, society, and the environment. For example, if there were an increase in the consumption of cigarettes, Buddhist economists try to decipher how this increase affects the pollution levels in the environment, its impact on passive smokers and active smokers, and the various health hazards that come along with smoking, thus taking into consideration the ethical side of economics. The ethical aspect of it is partly judged by the outcomes it brings and partly by the qualities that lead to it.

The Buddhist point of view ascribes to work three functions: to give man a chance to utilize and develop his aptitude; to enable him to overcome his self-aggrandizement by engaging with other people in common tasks; and to bring forward the goods and services needed for a better existence.

Differences between traditional and Buddhist economics

There are a number of differences between traditional economics and Buddhist economics.

• While traditional economics concentrates on self-interest, the Buddhist view challenges it by changing the concept of self to Anatta or no-self. It posits that all things perceived by one's senses are not actually "I" or "mine" and therefore, humans must detach themselves from this feeling. Buddhist Economists believe that the self-interest based, opportunistic approach to ethics will always fail. According to Buddhist Economists, generosity is a viable economic model of mutual reciprocity, because human beings are homines reciprocantes who tend to reciprocate to feelings (either positively or negatively) by giving back more than what is given to them.
• Traditional economists emphasize importance to maximizing profits and individual gains, while the underlying principle of Buddhist economics is to minimize suffering (losses) for all living or non-living things. Studies conducted by Buddhist economists correlates that human beings show greater sensitivity to loss than to gains, and concluded that people should concentrate more on reducing the former.
• There is a difference with respect to the concept of desire. Traditional economics encourages material wealth and desire in which people attempt to accumulate more wealth to satisfy those cravings. In contrast, in Buddhist economics, importance is given to simplify one's desires. According to Buddhist economists, apart from the basic necessities like food, shelter, clothing, and medicines, other materialistic needs should be minimized. Buddhist economists say that overall well-being decreases if people pursue meaningless desires; wanting less will benefit the person, the community they live in, and nature overall.
• Views on the market are also different. While many economists advocate maximizing markets to a point of saturation, Buddhist economists aim at minimizing violence. Traditional economics do not take into consideration "primordial stakeholders", like future generations and the natural world because their vote is not considered relevant in terms of purchasing power. They think that other stakeholders such as poor and marginalized people are under-represented because of their inadequate purchasing power and preference is given to the strongest stakeholder. Therefore, they believe that the market is not an unbiased place, but truly representative of the economy. Thus, Buddhist economists advocate ahimsa or non-violence. Ahimsa prevents doing anything that directly causes suffering to oneself or others and urges to find solutions in a participatory way. Community supported agriculture is one such example of community-based economic activities. Buddhist economists believe that community-supported agriculture fosters trust, helps build value based communities and brings people closer to the land and their food source. Achieving this sustainability and non-violence requires restructuring of dominating configurations of modern business, which they advocate. This leads to de-emphasizing profit maximization as the ultimate motive and renewed emphasis on introducing small-scale, locally adaptable, substantive economic activities.
• Traditional economists try to maximize instrumental use where the value of any entity is determined by its marginal contribution to the production output while Buddhist economists feel that the real value of an entity is neither realized nor given importance to. Buddhist economists attempt to reduce instrumental use and form caring organizations that will be rewarded in terms of trust among the management, co-workers, and employees.
• Traditional economists tend to believe that bigger is better and more is more, whereas Buddhist economists believe that small is beautiful and less is more.
• Traditional economics gives importance to gross national product whereas Buddhist economics gives importance to gross national happiness.

Other beliefs

Buddhist economists believe that as long as work is considered a disutility for laborers and laborers a necessary evil for employers, the true potential of the laborers and employers cannot be achieved. In such a situation, employees will always prefer income without employment and employers will always prefer output without employees. They feel that if the nature of work is truly appreciated and applied, it will be as important to the brain as food is to the body. It will nourish man and motivate him to do his best. According to them, goods should not be considered more important than people and consumption more important than creative activity. They feel that as a result of this, the focus shifts from the worker to the product of the work, the human to the subhuman, which is wrong.

According to them, people are unable to feel liberated not because of wealth but because of their attachment to wealth. In the same way, they say that it is the craving for pleasurable baubles and not the enjoyment from them that holds humans back.

Buddhist economists do not believe in measuring standard of living by the amount of consumption because according to them, obtaining maximum well being as a result of minimum consumption is more important than obtaining maximum well being from maximum consumption. Thus, they feel that the concept of being "better off" because of greater levels of consumption is not a true measure of happiness.

From the point of view of a Buddhist economist, the most rational way of economic life is being self-sufficient and producing local resources for local needs and depending on imports and exports is uneconomic and justifiable only in a few cases and on a small scale. Thus, they believe in economic development, independent of foreign aid.

Buddhist economics also gives importance to natural, renewable, and non-renewable resources. They feel that non-renewable resources should only be used when most needed and then also with utmost care, meticulously planning out its use. They believe that using them extravagantly is violent and not in keeping with the Buddhist belief of nonviolence. According to them, if the entire population relies on non-renewable resources for their existence, they are behaving parasitically, preying on capital goods instead of income. Adding to this, they feel that this uneven distribution and ever increasing exploitation of natural resources will lead to violence between man.

They also believe that satisfaction need not necessarily be felt only when something tangible is got back in return for giving something or something material is gained, as stated in modern economics. They say that the feeling of satisfaction can be achieved even when one parts with something without getting anything tangible in return. An example is when one gives presents to their loved ones simply because they want them to be happy.

Buddhist economists believe that production is a very misleading term. According to them, to produce something new, the old form has to be destroyed. Therefore, production and consumption become complementary to each other. Taking this into consideration, they advocate non-production in certain cases because when one produces less materialistic things, they reduce exploitation of the world's resources and lead the life of a responsible and aware citizen.

The middle way of living

The concept of the "middle way" says that time should be divided between working towards consumption and meditation and the optimal allocation between these two activities will be when some meditation is utilized to lower the desire for consumption and to be satisfied with lesser consumption and the work that it involves. In economic terms this means "the marginal productivity of labor utilized in producing consumption goods is equal to the marginal effectiveness of the meditation involved in economizing on consumption without bringing about any change in satisfaction".