Niobium

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Niobium,  ₄₁Nb

Niobium
Pronunciation	/naɪˈoʊbiəm/ ​(ny-OH-bee-əm)
Appearance	gray metallic, bluish when oxidized
Standard atomic weight Ar, std(Nb)	92.90637(1)
Niobium 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 V ↑ Nb ↓ Ta zirconium ← niobium → molybdenum
Atomic number (Z)	41
Group	group 5
Period	period 5
Block	d-block
Element category	transition metal
Electron configuration	[Kr] 4d4 5s1
Electrons per shell	2, 8, 18, 12, 1
Physical properties
Phase at STP	solid
Melting point	2750 K ​(2477 °C, ​4491 °F)
Boiling point	5017 K ​(4744 °C, ​8571 °F)
Density (near r.t.)	8.57 g/cm3
Heat of fusion	30 kJ/mol
Heat of vaporization	689.9 kJ/mol
Molar heat capacity	24.60 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2942 3207 3524 3910 4393 5013
Atomic properties
Oxidation states	−3, −1, +1, +2, +3, +4, +5 (a mildly acidic oxide)
Electronegativity	Pauling scale: 1.6
Ionization energies	1st: 652.1 kJ/mol 2nd: 1380 kJ/mol 3rd: 2416 kJ/mol
Atomic radius	empirical: 146 pm
Covalent radius	164±6 pm
Spectral lines of niobium
Other properties
Natural occurrence	primordial
Crystal structure	​body-centered cubic (bcc)
Speed of sound thin rod	3480 m/s (at 20 °C)
Thermal expansion	7.3 µm/(m·K)
Thermal conductivity	53.7 W/(m·K)
Electrical resistivity	152 nΩ·m (at 0 °C)
Magnetic ordering	paramagnetic
Young's modulus	105 GPa
Shear modulus	38 GPa
Bulk modulus	170 GPa
Poisson ratio	0.40
Mohs hardness	6.0
Vickers hardness	870–1320 MPa
Brinell hardness	735–2450 MPa
CAS Number	7440-03-1
History
Naming	after Niobe in Greek mythology, daughter of Tantalus (tantalum)
Discovery	Charles Hatchett (1801)
First isolation	Christian Wilhelm Blomstrand (1864)
Recognized as a distinct element by	Heinrich Rose (1844)
Main isotopes of niobium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct 90Nb syn 15 h β+ 90Zr 91Nb syn 680 y ε 91Zr 91mNb syn 61 d IT 91Nb 92m1Nb syn 10 d ε 92Zr γ – 92Nb trace 3.47×107 y ε 92Zr γ – 93Nb 100% stable 93mNb syn 16 y IT 93Nb 94Nb trace 20.3×103 y β− 94Mo γ – 95Nb syn 35 d β− 95Mo γ – 95mNb syn 4 d IT 95Nb 96Nb syn 24 h β− 96Mo

Niobium, formerly known as columbium, is a chemical element with the symbol Nb (formerly Cb) and atomic number 41. Niobium is a light grey, crystalline, and ductile transition metal. Pure Niobium has a hardness similar to that of pure titanium, and it has similar ductility to iron. Niobium oxidizes in the earth's atmosphere very slowly, hence its application in jewelry as a hypoallergenic alternative to nickel. Niobium is often found in the minerals pyrochlore and columbite, hence the former name "columbium". Its name comes from Greek mythology, specifically Niobe, who was the daughter of Tantalus, the namesake of tantalum. The name reflects the great similarity between the two elements in their physical and chemical properties, making them difficult to distinguish.

The English chemist Charles Hatchett reported a new element similar to tantalum in 1801 and named it columbium. In 1809, the English chemist William Hyde Wollaston wrongly concluded that tantalum and columbium were identical. The German chemist Heinrich Rose determined in 1846 that tantalum ores contain a second element, which he named niobium. In 1864 and 1865, a series of scientific findings clarified that niobium and columbium were the same element (as distinguished from tantalum), and for a century both names were used interchangeably. Niobium was officially adopted as the name of the element in 1949, but the name columbium remains in current use in metallurgy in the United States.

It was not until the early 20th century that niobium was first used commercially. Brazil is the leading producer of niobium and ferroniobium, an alloy of 60–70% niobium with iron. Niobium is used mostly in alloys, the largest part in special steel such as that used in gas pipelines. Although these alloys contain a maximum of 0.1%, the small percentage of niobium enhances the strength of the steel. The temperature stability of niobium-containing superalloys is important for its use in jet and rocket engines.

Niobium is used in various superconducting materials. These superconducting alloys, also containing titanium and tin, are widely used in the superconducting magnets of MRI scanners. Other applications of niobium include welding, nuclear industries, electronics, optics, numismatics, and jewelry. In the last two applications, the low toxicity and iridescence produced by anodization are highly desired properties. Niobium is considered a technology-critical element.

History

Charles Hatchett identified the element columbium within a mineral discovered in Connecticut, US.

 

Picture of a Hellenistic sculpture representing Niobe by Giorgio Sommer

 

Niobium was identified by English chemist Charles Hatchett in 1801. He found a new element in a mineral sample that had been sent to England from Connecticut, United States in 1734 by John Winthrop F.R.S. (grandson of John Winthrop the Younger) and named the mineral columbite and the new element columbium after Columbia, the poetical name for the United States. The columbium discovered by Hatchett was probably a mixture of the new element with tantalum.

Subsequently, there was considerable confusion over the difference between columbium (niobium) and the closely related tantalum. In 1809, English chemist William Hyde Wollaston compared the oxides derived from both columbium—columbite, with a density 5.918 g/cm³, and tantalum—tantalite, with a density over 8 g/cm³, and concluded that the two oxides, despite the significant difference in density, were identical; thus he kept the name tantalum. This conclusion was disputed in 1846 by German chemist Heinrich Rose, who argued that there were two different elements in the tantalite sample, and named them after children of Tantalus: niobium (from Niobe) and pelopium (from Pelops). This confusion arose from the minimal observed differences between tantalum and niobium. The claimed new elements pelopium, ilmenium, and dianium were in fact identical to niobium or mixtures of niobium and tantalum.

The differences between tantalum and niobium were unequivocally demonstrated in 1864 by Christian Wilhelm Blomstrand and Henri Etienne Sainte-Claire Deville, as well as Louis J. Troost, who determined the formulas of some of the compounds in 1865 and finally by Swiss chemist Jean Charles Galissard de Marignac in 1866, who all proved that there were only two elements. Articles on ilmenium continued to appear until 1871.

De Marignac was the first to prepare the metal in 1864, when he reduced niobium chloride by heating it in an atmosphere of hydrogen. Although de Marignac was able to produce tantalum-free niobium on a larger scale by 1866, it was not until the early 20th century that niobium was used in incandescent lamp filaments, the first commercial application. This use quickly became obsolete through the replacement of niobium with tungsten, which has a higher melting point. That niobium improves the strength of steel was first discovered in the 1920s, and this application remains its predominant use. In 1961, the American physicist Eugene Kunzler and coworkers at Bell Labs discovered that niobium-tin continues to exhibit superconductivity in the presence of strong electric currents and magnetic fields, making it the first material to support the high currents and fields necessary for useful high-power magnets and electrical power machinery. This discovery enabled — two decades later — the production of long multi-strand cables wound into coils to create large, powerful electromagnets for rotating machinery, particle accelerators, and particle detectors.

Naming the element

Columbium (symbol "Cb") was the name originally bestowed by Hatchett upon his discovery of the metal in 1801. The name reflected that the type specimen of the ore came from America (Columbia). This name remained in use in American journals—the last paper published by American Chemical Society with columbium in its title dates from 1953—while niobium was used in Europe. To end this confusion, the name niobium was chosen for element 41 at the 15th Conference of the Union of Chemistry in Amsterdam in 1949. A year later this name was officially adopted by the International Union of Pure and Applied Chemistry (IUPAC) after 100 years of controversy, despite the chronological precedence of the name columbium. This was a compromise of sorts; the IUPAC accepted tungsten instead of wolfram in deference to North American usage; and niobium instead of columbium in deference to European usage. While many US chemical societies and government organizations typically use the official IUPAC name, some metallurgists and metal societies still use the original American name, "columbium".

Characteristics

Physical

Niobium is a lustrous, grey, ductile, paramagnetic metal in group 5 of the periodic table (see table), with an electron configuration in the outermost shells atypical for group 5. (This can be observed in the neighborhood of ruthenium (44), rhodium (45), and palladium (46).)

Although it is thought to have a body-centered cubic crystal structure from absolute zero to its melting point, high-resolution measurements of the thermal expansion along the three crystallographic axes reveal anisotropies which are inconsistent with a cubic structure. Therefore, further research and discovery in this area is expected. 

Niobium becomes a superconductor at cryogenic temperatures. At atmospheric pressure, it has the highest critical temperature of the elemental superconductors at 9.2 K. Niobium has the greatest magnetic penetration depth of any element. In addition, it is one of the three elemental Type II superconductors, along with vanadium and technetium. The superconductive properties are strongly dependent on the purity of the niobium metal.

When very pure, it is comparatively soft and ductile, but impurities make it harder.

The metal has a low capture cross-section for thermal neutrons; thus it is used in the nuclear industries where neutron transparent structures are desired.

Chemical

The metal takes on a bluish tinge when exposed to air at room temperature for extended periods. Despite a high melting point in elemental form (2,468 °C), it has a lower density than other refractory metals. Furthermore, it is corrosion-resistant, exhibits superconductivity properties, and forms dielectric oxide layers. 

Niobium is slightly less electropositive and more compact than its predecessor in the periodic table, zirconium, whereas it is virtually identical in size to the heavier tantalum atoms, as a result of the lanthanide contraction. As a result, niobium's chemical properties are very similar to those for tantalum, which appears directly below niobium in the periodic table. Although its corrosion resistance is not as outstanding as that of tantalum, the lower price and greater availability make niobium attractive for less demanding applications, such as vat linings in chemical plants.

Isotopes

Niobium in the Earth's crust comprises one stable isotope, ⁹³Nb. By 2003, at least 32 radioisotopes had been synthesized, ranging in atomic mass from 81 to 113. The most stable of these is ⁹²Nb with a half-life of 34.7 million years. One of the least stable is ¹¹³Nb, with an estimated half-life of 30 milliseconds. Isotopes that are lighter than the stable ⁹³Nb tend to decay by β⁺ decay, and those that are heavier tend to decay by β⁻ decay, with some exceptions. ⁸¹Nb, ⁸²Nb, and ⁸⁴Nb have minor β⁺ delayed proton emission decay paths, ⁹¹Nb decays by electron capture and positron emission, and ⁹²Nb decays by both β⁺ and β⁻ decay.

At least 25 nuclear isomers have been described, ranging in atomic mass from 84 to 104. Within this range, only ⁹⁶Nb, ¹⁰¹Nb, and ¹⁰³Nb do not have isomers. The most stable of niobium's isomers is ^93mNb with a half-life of 16.13 years. The least stable isomer is ^84mNb with a half-life of 103 ns. All of niobium's isomers decay by isomeric transition or beta decay except ^92m1Nb, which has a minor electron capture branch.

Occurrence

Niobium is estimated to be the 34th most common element in the Earth’s crust, with 20 ppm. Some think that the abundance on Earth is much greater, and that the element's high density has concentrated it in the Earth’s core. The free element is not found in nature, but niobium occurs in combination with other elements in minerals. Minerals that contain niobium often also contain tantalum. Examples include columbite ((Fe,Mn)(Nb,Ta)₂O₆) and columbite–tantalite (or coltan, (Fe,Mn)(Ta,Nb)₂O₆). Columbite–tantalite minerals (the most common species being columbite-(Fe) and tantalite-(Fe), where "-(Fe)" is the Levinson suffix informing about the prevailence of iron over other elements like manganese) are most usually found as accessory minerals in pegmatite intrusions, and in alkaline intrusive rocks. Less common are the niobates of calcium, uranium, thorium and the rare earth elements. Examples of such niobates are pyrochlore ((Na,Ca)₂Nb₂O₆(OH,F)) (now a group name, with a relatively common example being, e.g., fluorcalciopyrochlore) and euxenite (correctly named euxenite-(Y)) ((Y,Ca,Ce,U,Th)(Nb,Ta,Ti)₂O₆). These large deposits of niobium have been found associated with carbonatites (carbonate-silicate igneous rocks) and as a constituent of pyrochlore.

The three largest currently mined deposits of pyrochlore, two in Brazil and one in Canada, were found in the 1950s, and are still the major producers of niobium mineral concentrates. The largest deposit is hosted within a carbonatite intrusion in Araxá, state of Minas Gerais, Brazil, owned by CBMM (Companhia Brasileira de Metalurgia e Mineração); the other active Brazilian deposit is located near Catalão, state of Goiás, and owned by China Molybdenum, also hosted within a carbonatite intrusion. Together, those two mines produce about 88% of the world's supply. Brazil also has a large but still unexploited deposit near São Gabriel da Cachoeira, state of Amazonas, as well as a few smaller deposits, notably in the state of Roraima.

The third largest producer of niobium is the carbonatite-hosted Niobec mine, in Saint-Honoré, near Chicoutimi, Quebec, Canada, owned by Magris Resources. It produces between 7% and 10% of the world's supply.

Production

Niobium producers in 2006 to 2015

 

After the separation from the other minerals, the mixed oxides of tantalum Ta₂O₅ and niobium Nb₂O₅ are obtained. The first step in the processing is the reaction of the oxides with hydrofluoric acid:

Ta₂O₅ + 14 HF → 2 H₂[TaF₇] + 5 H₂O

Nb₂O₅ + 10 HF → 2 H₂[NbOF₅] + 3 H₂O

The first industrial scale separation, developed by de Marignac, exploits the differing solubilities of the complex niobium and tantalum fluorides, dipotassium oxypentafluoroniobate monohydrate (K₂[NbOF₅]·H₂O) and dipotassium heptafluorotantalate (K₂[TaF₇]) in water. Newer processes use the liquid extraction of the fluorides from aqueous solution by organic solvents like cyclohexanone. The complex niobium and tantalum fluorides are extracted separately from the organic solvent with water and either precipitated by the addition of potassium fluoride to produce a potassium fluoride complex, or precipitated with ammonia as the pentoxide:

H₂[NbOF₅] + 2 KF → K₂[NbOF₅]↓ + 2 HF

Followed by:

2 H₂[NbOF₅] + 10 NH₄OH → Nb₂O₅↓ + 10 NH₄F + 7 H₂O

Several methods are used for the reduction to metallic niobium. The electrolysis of a molten mixture of K₂[NbOF₅] and sodium chloride is one; the other is the reduction of the fluoride with sodium. With this method, a relatively high purity niobium can be obtained. In large scale production, Nb₂O₅ is reduced with hydrogen or carbon. In the aluminothermic reaction, a mixture of iron oxide and niobium oxide is reacted with aluminium:

3 Nb₂O₅ + Fe₂O₃ + 12 Al → 6 Nb + 2 Fe + 6 Al₂O₃

Small amounts of oxidizers like sodium nitrate are added to enhance the reaction. The result is aluminium oxide and ferroniobium, an alloy of iron and niobium used in steel production. Ferroniobium contains between 60 and 70% niobium. Without iron oxide, the aluminothermic process is used to produce niobium. Further purification is necessary to reach the grade for superconductive alloys. Electron beam melting under vacuum is the method used by the two major distributors of niobium.

As of 2013, CBMM from Brazil controlled 85 percent of the world's niobium production. The United States Geological Survey estimates that the production increased from 38,700 tonnes in 2005 to 44,500 tonnes in 2006. Worldwide resources are estimated to be 4,400,000 tonnes. During the ten-year period between 1995 and 2005, the production more than doubled, starting from 17,800 tonnes in 1995. Between 2009 and 2011, production was stable at 63,000 tonnes per year, with a slight decrease in 2012 to only 50,000 tonnes per year.

Lesser amounts are found in Malawi's Kanyika Deposit (Kanyika mine).

Compounds

In many ways, niobium is similar to tantalum and zirconium. It reacts with most nonmetals at high temperatures; with fluorine at room temperature; with chlorine and hydrogen at 200 °C; and with nitrogen at 400 °C, with products that are frequently interstitial and nonstoichiometric. The metal begins to oxidize in air at 200 °C. It resists corrosion by fused alkalis and by acids, including aqua regia, hydrochloric, sulfuric, nitric and phosphoric acids. Niobium is attacked by hydrofluoric acid and hydrofluoric/nitric acid mixtures. 

Although niobium exhibits all of the formal oxidation states from +5 to −1, the most common compounds have niobium in the +5 state. Characteristically, compounds in oxidation states less than 5+ display Nb–Nb bonding. In aqueous solutions, niobium only exhibit the +5 oxidation state. It is also readily prone to hydrolysis and is barely soluble in dilute solutions of hydrochloric, sulfuric, nitric and phosphoric acids due to the precipitation of hydrous Nb oxide. Nb(V) is also slightly soluble in alkaline media due to the formation of soluble polyoxoniobate species.

Oxides and sulfides

Niobium forms oxides in the oxidation states +5 (Nb₂O₅), +4 (NbO₂), +3 (Nb
₂O
₃), and the rarer oxidation state, +2 (NbO). Most common is the pentoxide, precursor to almost all niobium compounds and alloys. Niobates are generated by dissolving the pentoxide in basic hydroxide solutions or by melting it in alkali metal oxides. Examples are lithium niobate (LiNbO₃) and lanthanum niobate (LaNbO₄). In the lithium niobate is a trigonally distorted perovskite-like structure, whereas the lanthanum niobate contains lone NbO³⁻
₄ ions. The layered niobium sulfide (NbS₂) is also known.

Materials can be coated with a thin film of niobium(V) oxide chemical vapor deposition or atomic layer deposition processes, produced by the thermal decomposition of niobium(V) ethoxide above 350 °C.

Halides

A sample of niobium pentachloride (yellow portion) that has partially hydrolyzed (white material).

 

Ball-and-stick model of niobium pentachloride, which exists as a dimer

 

Niobium forms halides in the oxidation states of +5 and +4 as well as diverse substoichiometric compounds. The pentahalides (NbX
₅) feature octahedral Nb centres. Niobium pentafluoride (NbF₅) is a white solid with a melting point of 79.0 °C and niobium pentachloride (NbCl₅) is yellow (see image at left) with a melting point of 203.4 °C. Both are hydrolyzed to give oxides and oxyhalides, such as NbOCl₃. The pentachloride is a versatile reagent used to generate the organometallic compounds, such as niobocene dichloride ((C
₅H
₅)
₂NbCl
₂). The tetrahalides (NbX
₄) are dark-coloured polymers with Nb-Nb bonds; for example, the black hygroscopic niobium tetrafluoride (NbF₄) and brown niobium tetrachloride (NbCl₄). 

Anionic halide compounds of niobium are well known, owing in part to the Lewis acidity of the pentahalides. The most important is [NbF₇]²⁻, an intermediate in the separation of Nb and Ta from the ores. This heptafluoride tends to form the oxopentafluoride more readily than does the tantalum compound. Other halide complexes include octahedral [NbCl₆]⁻:

Nb₂Cl₁₀ + 2 Cl⁻ → 2 [NbCl₆]⁻

As with other metals with low atomic numbers, a variety of reduced halide cluster ions is known, the prime example being [Nb₆Cl₁₈]⁴⁻.

Nitrides and carbides

Other binary compounds of niobium include niobium nitride (NbN), which becomes a superconductor at low temperatures and is used in detectors for infrared light. The main niobium carbide is NbC, an extremely hard, refractory, ceramic material, commercially used in cutting tool bits.

Applications

A niobium foil

 

Out of 44,500 tonnes of niobium mined in 2006, an estimated 90% was used in high-grade structural steel. The second largest application is superalloys. Niobium alloy superconductors and electronic components account for a very small share of the world production.

Steel production

Niobium is an effective microalloying element for steel, within which it forms niobium carbide and niobium nitride. These compounds improve the grain refining, and retard recrystallization and precipitation hardening. These effects in turn increase the toughness, strength, formability, and weldability. Within microalloyed stainless steels, the niobium content is a small (less than 0.1%) but important addition to high strength low alloy steels that are widely used structurally in modern automobiles. Niobium is sometimes used in considerably higher quantities for highly wear-resistant machine components and knives, as high as 3% in Crucible CPM S110V stainless steel.

These same niobium alloys are often used in pipeline construction.

Superalloys

Apollo 15 CSM in lunar orbit with the dark rocket nozzle made from niobium-titanium alloy

 

Quantities of niobium are used in nickel-, cobalt-, and iron-based superalloys in proportions as great as 6.5% for such applications as jet engine components, gas turbines, rocket subassemblies, turbo charger systems, heat resisting, and combustion equipment. Niobium precipitates a hardening γ''-phase within the grain structure of the superalloy.

One example superalloy is Inconel 718, consisting of roughly 50% nickel, 18.6% chromium, 18.5% iron, 5% niobium, 3.1% molybdenum, 0.9% titanium, and 0.4% aluminium. These superalloys were used, for example, in advanced air frame systems for the Gemini program. Another niobium alloy was used for the nozzle of the Apollo Service Module. Because niobium is oxidized at temperatures above 400 °C, a protective coating is necessary for these applications to prevent the alloy from becoming brittle.

Niobium-based alloys

C-103 alloy was developed in the early 1960s jointly by the Wah Chang Corporation and Boeing Co. DuPont, Union Carbide Corp., General Electric Co. and several other companies were developing Nb-base alloys simultaneously, largely driven by the Cold War and Space Race. It is composed of 89% niobium, 10% hafnium and 1% titanium and is used for liquid rocket thruster nozzles, such as the main engine of the Apollo Lunar Modules.

The nozzle of the Merlin Vacuum series of engines developed by SpaceX for the upper stage of its Falcon 9 rocket is made from a niobium alloy.

The reactivity of niobium with oxygen requires it to be worked in a vacuum or inert atmosphere, which significantly increases the cost and difficulty of production. Vacuum arc remelting (VAR) and electron beam melting (EBM), novel processes at the time, enabled the development of niobium and other reactive metals. The project that yielded C-103 began in 1959 with as many as 256 experimental niobium alloys in the "C-series" (possibly from columbium) that could be melted as buttons and rolled into sheet. Wah Chang had an inventory of hafnium, refined from nuclear-grade zirconium alloys, that it wanted to put to commercial use. The 103rd experimental composition of the C-series alloys, Nb-10Hf-1Ti, had the best combination of formability and high-temperature properties. Wah Chang fabricated the first 500-lb heat of C-103 in 1961, ingot to sheet, using EBM and VAR. The intended applications included turbine engines and liquid metal heat exchangers. Competing niobium alloys from that era included FS85 (Nb-10W-28Ta-1Zr) from Fansteel Metallurgical Corp., Cb129Y (Nb-10W-10Hf-0.2Y) from Wah Chang and Boeing, Cb752 (Nb-10W-2.5Zr) from Union Carbide, and Nb1Zr from Superior Tube Co.

Superconducting magnets

A 3-tesla clinical magnetic resonance imaging scanner using niobium superconducting alloy

 

Niobium-germanium (Nb
₃Ge), niobium-tin (Nb
₃Sn), as well as the niobium-titanium alloys are used as a type II superconductor wire for superconducting magnets. These superconducting magnets are used in magnetic resonance imaging and nuclear magnetic resonance instruments as well as in particle accelerators. For example, the Large Hadron Collider uses 600 tons of superconducting strands, while the International Thermonuclear Experimental Reactor uses an estimated 600 tonnes of Nb₃Sn strands and 250 tonnes of NbTi strands. In 1992 alone, more than US$1 billion worth of clinical magnetic resonance imaging systems were constructed with niobium-titanium wire.

Other superconductors

A 1.3 GHz 9-cell SRF cavity made from niobium is on display at Fermilab

 

The superconducting radio frequency (SRF) cavities used in the free-electron lasers FLASH (result of the cancelled TESLA linear accelerator project) and XFEL are made from pure niobium. A cryomodule team at Fermilab used the same SRF technology from the FLASH project to develop 1.3 GHz nine-cell SRF cavities made from pure niobium. The cavities will be used in the 30-kilometre (19 mi) linear particle accelerator of the International Linear Collider. The same technology will be used in LCLS-II at SLAC National Accelerator Laboratory and PIP-II at Fermilab.

The high sensitivity of superconducting niobium nitride bolometers make them an ideal detector for electromagnetic radiation in the THz frequency band. These detectors were tested at the Submillimeter Telescope, the South Pole Telescope, the Receiver Lab Telescope, and at APEX, and are now used in the HIFI instrument on board the Herschel Space Observatory.

Other uses

Electroceramics

Lithium niobate, which is a ferroelectric, is used extensively in mobile telephones and optical modulators, and for the manufacture of surface acoustic wave devices. It belongs to the ABO₃ structure ferroelectrics like lithium tantalate and barium titanate. Niobium capacitors are available as alternative to tantalum capacitors, but tantalum capacitors still predominate. Niobium is added to glass to obtain a higher refractive index, making possible thinner and lighter corrective glasses.

Hypoallergenic applications: medicine and jewelry

Niobium and some niobium alloys are physiologically inert and hypoallergenic. For this reason, niobium is used in prosthetics and implant devices, such as pacemakers. Niobium treated with sodium hydroxide forms a porous layer that aids osseointegration.

Like titanium, tantalum, and aluminium, niobium can be heated and anodized ("reactive metal anodization") to produce a wide array of iridescent colours for jewelry, where its hypoallergenic property is highly desirable.

Numismatics

A 150 Years Semmering Alpine Railway Coin made of niobium and silver

 

Niobium is used as a precious metal in commemorative coins, often with silver or gold. For example, Austria produced a series of silver niobium euro coins starting in 2003; the colour in these coins is created by the diffraction of light by a thin anodized oxide layer. In 2012, ten coins are available showing a broad variety of colours in the centre of the coin: blue, green, brown, purple, violet, or yellow. Two more examples are the 2004 Austrian €25 150 Years Semmering Alpine Railway commemorative coin, and the 2006 Austrian €25 European Satellite Navigation commemorative coin. The Austrian mint produced for Latvia a similar series of coins starting in 2004, with one following in 2007. In 2011, the Royal Canadian Mint started production of a $5 sterling silver and niobium coin named Hunter's Moon in which the niobium was selectively oxidized, thus creating unique finishes where no two coins are exactly alike.

Other

The arc-tube seals of high pressure sodium vapor lamps are made from niobium, sometimes alloyed with 1% of zirconium; niobium has a very similar coefficient of thermal expansion, matching the sintered alumina arc tube ceramic, a translucent material which resists chemical attack or reduction by the hot liquid sodium and sodium vapour contained inside the operating lamp.

Niobium is used in arc welding rods for some stabilized grades of stainless steel and in anodes for cathodic protection systems on some water tanks, which are then usually plated with platinum.

Niobium is an important component of high-performance heterogeneous catalysts for the production of acrylic acid by selective oxidation of propane.

Niobium is used to make the high voltage wire of the Solar Corona particles receptor module of the Parker Solar Probe. 

Precautions

Niobium

Hazards
GHS signal word	Not listed as hazardous
NFPA 704	0 0 0

Niobium has no known biological role. While niobium dust is an eye and skin irritant and a potential fire hazard, elemental niobium on a larger scale is physiologically inert (and thus hypoallergenic) and harmless. It is frequently used in jewelry and has been tested for use in some medical implants.

Niobium-containing compounds are rarely encountered by most people, but some are toxic and should be treated with care. The short- and long-term exposure to niobates and niobium chloride, two chemicals that are water-soluble, have been tested in rats. Rats treated with a single injection of niobium pentachloride or niobates show a median lethal dose (LD₅₀) between 10 and 100 mg/kg. For oral administration the toxicity is lower; a study with rats yielded a LD₅₀ after seven days of 940 mg/kg.

Human factors and ergonomics

From Wikipedia, the free encyclopedia

Human factors and ergonomics (commonly referred to as human factors) is the application of psychological and physiological principles to the (engineering and) design of products, processes, and systems. The goal of human factors is to reduce human error, increase productivity, and enhance safety and comfort with a specific focus on the interaction between the human and the thing of interest. It is not simply changes or amendments to the work environment but encompasses theory, methods, data and principles all applied in the field of ergonomics.

The field is a combination of numerous disciplines, such as psychology, sociology, engineering, biomechanics, industrial design, physiology, anthropometry, interaction design, visual design, user experience, and user interface design. In research, human factors employs the scientific method to study human behavior so that the resultant data may be applied to the four primary goals. In essence, it is the study of designing equipment, devices and processes that fit the human body and its cognitive abilities. The two terms "human factors" and "ergonomics" are essentially synonymous.

The International Ergonomics Association defines ergonomics or human factors as follows:

Ergonomics (or human factors) is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data and methods to design to optimize human well-being and overall system performance.

Human factors is employed to fulfill the goals of occupational health and safety and productivity. It is relevant in the design of such things as safe furniture and easy-to-use interfaces to machines and equipment. 

Proper ergonomic design is necessary to prevent repetitive strain injuries and other musculoskeletal disorders, which can develop over time and can lead to long-term disability. 

Human factors and ergonomics is concerned with the "fit" between the user, equipment, and environment or "fitting a job to a person". It accounts for the user's capabilities and limitations in seeking to ensure that tasks, functions, information, and the environment suit that user. 

To assess the fit between a person and the used technology, human factors specialists or ergonomists consider the job (activity) being done and the demands on the user; the equipment used (its size, shape, and how appropriate it is for the task), and the information used (how it is presented, accessed, and changed). Ergonomics draws on many disciplines in its study of humans and their environments, including anthropometry, biomechanics, mechanical engineering, industrial engineering, industrial design, information design, kinesiology, physiology, cognitive psychology, industrial and organizational psychology, and space psychology.

Etymology

The term ergonomics (from the Greek ἔργον, meaning "work", and νόμος, meaning "natural law") first entered the modern lexicon when Polish scientist Wojciech Jastrzębowski used the word in his 1857 article Rys ergonomji czyli nauki o pracy, opartej na prawdach poczerpniętych z Nauki Przyrody (The Outline of Ergonomics; i.e. Science of Work, Based on the Truths Taken from the Natural Science). The French scholar Jean-Gustave Courcelle-Seneuil, apparently without knowledge of Jastrzębowski's article, used the word with a slightly different meaning in 1858. The introduction of the term to the English lexicon is widely attributed to British psychologist Hywel Murrell, at the 1949 meeting at the UK's Admiralty, which led to the foundation of The Ergonomics Society. He used it to encompass the studies in which he had been engaged during and after World War II.

The expression human factors is a predominantly North American term which has been adopted to emphasize the application of the same methods to non-work-related situations. A "human factor" is a physical or cognitive property of an individual or social behavior specific to humans that may influence the functioning of technological systems. The terms "human factors" and "ergonomics" are essentially synonymous.

Domains of specialization

Ergonomics comprise three main fields of research: physical, cognitive and organizational ergonomics. 

There are many specializations within these broad categories. Specializations in the field of physical ergonomics may include visual ergonomics. Specializations within the field of cognitive ergonomics may include usability, human–computer interaction, and user experience engineering. 

Some specializations may cut across these domains: Environmental ergonomics is concerned with human interaction with the environment as characterized by climate, temperature, pressure, vibration, light. The emerging field of human factors in highway safety uses human factor principles to understand the actions and capabilities of road users – car and truck drivers, pedestrians, cyclists, etc. – and use this knowledge to design roads and streets to reduce traffic collisions. Driver error is listed as a contributing factor in 44% of fatal collisions in the United States, so a topic of particular interest is how road users gather and process information about the road and its environment, and how to assist them to make the appropriate decision.

New terms are being generated all the time. For instance, "user trial engineer" may refer to a human factors professional who specializes in user trials. Although the names change, human factors professionals apply an understanding of human factors to the design of equipment, systems and working methods to improve comfort, health, safety, and productivity. 

According to the International Ergonomics Association, within the discipline of ergonomics there exist domains of specialization.

Physical ergonomics

Physical ergonomics: the science of designing user interaction with equipment and workplaces to fit the user.

 

Physical ergonomics is concerned with human anatomy, and some of the anthropometric, physiological and bio mechanical characteristics as they relate to physical activity. Physical ergonomic principles have been widely used in the design of both consumer and industrial products. Risk factors such as localized mechanical pressures, force and  posture in a sedentary office environment lead to injuries attributed to an occupational environment. Physical ergonomics is important in the medical field, particularly to those diagnosed with physiological ailments or disorders such as arthritis (both chronic and temporary) or carpal tunnel syndrome. Pressure that is insignificant or imperceptible to those unaffected by these disorders may be very painful, or render a device unusable, for those who are. Many ergonomically designed products are also used or recommended to treat or prevent such disorders, and to treat pressure-related chronic pain.

One of the most prevalent types of work-related injuries is musculoskeletal disorder. Work-related musculoskeletal disorders (WRMDs) result in persistent pain, loss of functional capacity and work disability, but their initial diagnosis is difficult because they are mainly based on complaints of pain and other symptoms. Every year, 1.8 million U.S. workers experience WRMDs and nearly 600,000 of the injuries are serious enough to cause workers to miss work. Certain jobs or work conditions cause a higher rate of worker complaints of undue strain, localized fatigue, discomfort, or pain that does not go away after overnight rest. These types of jobs are often those involving activities such as repetitive and forceful exertions; frequent, heavy, or overhead lifts; awkward work positions; or use of vibrating equipment. The Occupational Safety and Health Administration (OSHA) has found substantial evidence that ergonomics programs can cut workers' compensation costs, increase productivity and decrease employee turnover. Mitigation solutions can include both short term and long term solutions.  Short and long term solutions involve awareness training, positioning of the body, furniture and equipment and ergonomic exercises. Sit-stand stations and computer accessories that provide soft surfaces for resting the palm as well as split keyboards are recommended.  Additionally, resources within the HR department can be allocated to provide assessments to employees to ensure the above listed criteria is met. Therefore, it is important to gather data to identify jobs or work conditions that are most problematic, using sources such as injury and illness logs, medical records, and job analyses.

Ergonomically correct Keyboard

 

Innovative workstations that are being tested include: sit-stand desks, treadmill desks, pedal devices and cycle ergometers. In multiple studies these new workstations resulted in decreased waist circumference and psychological well being, however a significant number of additional studies have seen no marked improvement in health outcomes.

Cognitive ergonomics

Cognitive ergonomics is concerned with mental processes, such as perception, memory, reasoning, and motor response, as they affect interactions among humans and other elements of a system. (Relevant topics include mental workload, decision-making, skilled performance, human reliability, work stress and training as these may relate to human-system and Human-Computer Interaction design.) Epidemiological studies show a correlation between the time one spends sedentary and their cognitive function such as lowered mood and depression.

Organizational ergonomics

Organizational ergonomics is concerned with the optimization of socio-technical systems, including their organizational structures, policies, and processes. (Relevant topics include communication, crew resource management, work design, work systems, design of working times, teamwork, participatory design, community ergonomics, cooperative work, new work programs, virtual organizations, telework, and quality management.)

History of the field

In ancient societies

Some have stated that human ergonomics began with Australopithecus Prometheus (also known as “little foot”), a primate who created handheld tools out of different types of stone, clearly distinguishing  between tools based on their ability to perform designated tasks.  The foundations of the science of ergonomics appear to have been laid within the context of the culture of Ancient Greece. A good deal of evidence indicates that Greek civilization in the 5th century BC used ergonomic principles in the design of their tools, jobs, and workplaces. One outstanding example of this can be found in the description Hippocrates gave of how a surgeon's workplace should be designed and how the tools he uses should be arranged. The archaeological record also shows that the early Egyptian dynasties made tools and household equipment that illustrated ergonomic principles.

In industrial societies

Bernardino Ramazzini was one of the first people to systematically study the illness that resulted from work earning himself the nickname “father of occupational medicine”. In the late 1600s and early 1700s Ramazzini visited many worksites where he documented the movements of laborers and spoke to them about their ailments. He then published “De Morbis Artificum Diatriba” (italian for Diseases of Workers) which detailed occupations, common illnesses, remedies. In the 19th century, Frederick Winslow Taylor pioneered the "scientific management" method, which proposed a way to find the optimum method of carrying out a given task. Taylor found that he could, for example, triple the amount of coal that workers were shoveling by incrementally reducing the size and weight of coal shovels until the fastest shoveling rate was reached. Frank and Lillian Gilbreth expanded Taylor's methods in the early 1900s to develop the "time and motion study". They aimed to improve efficiency by eliminating unnecessary steps and actions. By applying this approach, the Gilbreths reduced the number of motions in bricklaying from 18 to 4.5, allowing bricklayers to increase their productivity from 120 to 350 bricks per hour.

However, this approach was rejected by Russian researchers who focused on the well being of the worker. At the First Conference on Scientific Organization of Labour (1921) Vladimir Bekhterev and Vladimir Nikolayevich Myasishchev criticised Taylorism. Bekhterev argued that "The ultimate ideal of the labour problem is not in it [Taylorism], but is in such organisation of the labour process that would yield a maximum of efficiency coupled with a minimum of health hazards, absence of fatigue and a guarantee of the sound health and all round personal development of the working people." Myasishchev rejected Frederick Taylor's proposal to turn man into a machine. Dull monotonous work was a temporary necessity until a corresponding machine can be developed. He also went on to suggest a new discipline of "ergology" to study work as an integral part of the re-organisation of work. The concept was taken up by Myasishchev's mentor, Bekhterev, in his final report on the conference, merely changing the name to "ergonology"

In aviation

Prior to World War I, the focus of aviation psychology was on the aviator himself, but the war shifted the focus onto the aircraft, in particular, the design of controls and displays, and the effects of altitude and environmental factors on the pilot. The war saw the emergence of aeromedical research and the need for testing and measurement methods. Studies on driver behavior started gaining momentum during this period, as Henry Ford started providing millions of Americans with automobiles. Another major development during this period was the performance of aeromedical research. By the end of World War I, two aeronautical labs were established, one at Brooks Air Force Base, Texas and the other at Wright-Patterson Air Force Base outside of Dayton, Ohio. Many tests were conducted to determine which characteristic differentiated the successful pilots from the unsuccessful ones. During the early 1930s, Edwin Link developed the first flight simulator. The trend continued and more sophisticated simulators and test equipment were developed. Another significant development was in the civilian sector, where the effects of illumination on worker productivity were examined. This led to the identification of the Hawthorne Effect, which suggested that motivational factors could significantly influence human performance.

World War II marked the development of new and complex machines and weaponry, and these made new demands on operators' cognition. It was no longer possible to adopt the Tayloristic principle of matching individuals to preexisting jobs. Now the design of equipment had to take into account human limitations and take advantage of human capabilities. The decision-making, attention, situational awareness and hand-eye coordination of the machine's operator became key in the success or failure of a task. There was substantial research conducted to determine the human capabilities and limitations that had to be accomplished. A lot of this research took off where the aeromedical research between the wars had left off. An example of this is the study done by Fitts and Jones (1947), who studied the most effective configuration of control knobs to be used in aircraft cockpits.

Much of this research transcended into other equipment with the aim of making the controls and displays easier for the operators to use. The entry of the terms "human factors" and "ergonomics" into the modern lexicon date from this period. It was observed that fully functional aircraft flown by the best-trained pilots, still crashed. In 1943 Alphonse Chapanis, a lieutenant in the U.S. Army, showed that this so-called "pilot error" could be greatly reduced when more logical and differentiable controls replaced confusing designs in airplane cockpits. After the war, the Army Air Force published 19 volumes summarizing what had been established from research during the war.

In the decades since World War II, human factors has continued to flourish and diversify. Work by Elias Porter and others within the RAND Corporation after WWII extended the conception of human factors. "As the thinking progressed, a new concept developed—that it was possible to view an organization such as an air-defense, man-machine system as a single organism and that it was possible to study the behavior of such an organism. It was the climate for a breakthrough." In the initial 20 years after the World War II, most activities were done by the "founding fathers": Alphonse Chapanis, Paul Fitts, and Small.

During the Cold War

The beginning of the Cold War led to a major expansion of Defense supported research laboratories. Also, many labs established during WWII started expanding. Most of the research following the war was military-sponsored. Large sums of money were granted to universities to conduct research. The scope of the research also broadened from small equipments to entire workstations and systems. Concurrently, a lot of opportunities started opening up in the civilian industry. The focus shifted from research to participation through advice to engineers in the design of equipment. After 1965, the period saw a maturation of the discipline. The field has expanded with the development of the computer and computer applications.

The Space Age created new human factors issues such as weightlessness and extreme g-forces. Tolerance of the harsh environment of space and its effects on the mind and body were widely studied.

Information age

The dawn of the Information Age has resulted in the related field of human–computer interaction (HCI). Likewise, the growing demand for and competition among consumer goods and electronics has resulted in more companies and industries including human factors in their product design. Using advanced technologies in human kinetics, body-mapping, movement patterns and heat zones, companies are able to manufacture purpose-specific garments, including full body suits, jerseys, shorts, shoes, and even underwear.

Present-day

Ergonomic evaluation in virtual environment

 

In physical ergonomics, digital tools and advanced software allow analysis of a workplace. An employee's movements are recorded using a motion capture tool and imported into an analyzing system. To detect hazardous postures and movements, traditional risk assessment methods are implemented in the software – for example, as in the ViveLab ergonomic assessment software RULA and NASA-OBI.

In virtual space, a biomechanically accurate model represents the worker. The body structure, sex, age and demographic group of the mannequin is adjustable to correspond to the properties of the employee. The software provides several different evaluations such as reachability test, spaghetti diagram, or visibility analysis. With these tools, ergonomists are able to redesign a workstation in a virtual environment and test it in iterations until the result is satisfactory.

Human factors organizations

Formed in 1946 in the UK, the oldest professional body for human factors specialists and ergonomists is The Chartered Institute of Ergonomics and Human Factors, formally known as the Institute of Ergonomics and Human Factors and before that, The Ergonomics Society. 

The Human Factors and Ergonomics Society (HFES) was founded in 1957. The Society's mission is to promote the discovery and exchange of knowledge concerning the characteristics of human beings that are applicable to the design of systems and devices of all kinds. 

The Association of Canadian Ergonomists - l'Association canadienne d'ergonomie (ACE) was founded in 1968. It was originally named the Human Factors Association of Canada (HFAC), with ACE (in French) added in 1984, and the consistent, bilingual title adopted in 1999. According to it 2017 mission statement, ACE unites and advances the knowledge and skills of ergonomics and human factors practitioners to optimise human and organisational well-being.

The International Ergonomics Association (IEA) is a federation of ergonomics and human factors societies from around the world. The mission of the IEA is to elaborate and advance ergonomics science and practice, and to improve the quality of life by expanding its scope of application and contribution to society. As of September 2008, the International Ergonomics Association has 46 federated societies and 2 affiliated societies.

Related organizations

The Institute of Occupational Medicine (IOM) was founded by the coal industry in 1969. From the outset the IOM employed an ergonomics staff to apply ergonomics principles to the design of mining machinery and environments. To this day, the IOM continues ergonomics activities, especially in the fields of musculoskeletal disorders; heat stress and the ergonomics of personal protective equipment (PPE). Like many in occupational ergonomics, the demands and requirements of an ageing UK workforce are a growing concern and interest to IOM ergonomists.

The International Society of Automotive Engineers (SAE) is a professional organization for mobility engineering professionals in the aerospace, automotive, and commercial vehicle industries. The Society is a standards development organization for the engineering of powered vehicles of all kinds, including cars, trucks, boats, aircraft, and others. The Society of Automotive Engineers has established a number of standards used in the automotive industry and elsewhere. It encourages the design of vehicles in accordance with established human factors principles. It is one of the most influential organizations with respect to ergonomics work in automotive design. This society regularly holds conferences which address topics spanning all aspects of human factors and ergonomics.

Practitioners

Human factors practitioners come from a variety of backgrounds, though predominantly they are psychologists (from the various subfields of industrial and organizational psychology, engineering psychology, cognitive psychology, perceptual psychology, applied psychology, and experimental psychology) and physiologists. Designers (industrial, interaction, and graphic), anthropologists, technical communication scholars and computer scientists also contribute. Typically, an ergonomist will have an undergraduate degree in psychology, engineering, design or health sciences, and usually a master's degree or doctoral degree in a related discipline. Though some practitioners enter the field of human factors from other disciplines, both M.S. and PhD degrees in Human Factors Engineering are available from several universities worldwide.

Ergonomics and the Sedentary Workplace

Contemporary offices did not exist until the 1830s with, Wojciech Jastrzębowsk’s seminal book on MSDergonomics following in 1857 and the first published study of posture appearing in 1955s.

 

As the American workforce began to shift towards sedentary employment, the prevalence of [WMSD/cognitive issues/ etc..] began to rise. In 1900, 41% of the US workforce was employed in agriculture but by 2000 that had dropped to 1.9%  This coincides with an increase in growth in desk-based employment (25% of all employment in 2000)  and the surveillance of non-fatal workplace injuries by OSHA and Bureau of Labor Statistics in 1971 .0-1.5 and occurs in a sitting or reclining position. Adults older than 50 years report spending more time sedentary and for adults older than 65 years this is often 80% of their awake time. Multiple studies show a dose-response relationship between sedentary time and all-cause mortality with an increase of 3% mortality per additional sedentary hour each day. High quantities of sedentary time without breaks is correlated to higher risk of chronic disease, obesity, cardiovascular disease, type 2 diabetes and cancer.

Currently, there is a large proportion of the overall workforce who is employed in low physical activity occupations. Sedentary behavior, such as spending long periods of time in seated positions poses a serious threat for injuries and additional health risks. Unfortunately, even though some workplaces make an effort to provide a well designed environment for sedentary employees, any employee who is performing large amounts of sitting will likely suffer discomfort. There are existing conditions that would predispose both individuals and populations to an increase in prevalence of living sedentary lifestyles, including: socioeconomic determinants, education levels, occupation, living environment, age (as mentioned above) and more. A study published by the Iranian Journal of Public Health examined socioeconomic factors and sedentary lifestyle effects for individuals in a working community. The study concluded that individuals who reported living in low income environments were more inclined to living sedentary behavior compared to those who reported being of high socioeconomic status. Individuals who achieve less education are also considered to be a high risk group to partake in sedentary lifestyles, however, each community is different and has different resources available that may vary this risk. Often times, larger worksites are associated with increased occupational sitting.Those who work in environments that are classified as business and office jobs are typically more exposed to sitting and sedentary behavior while in the workplace. Additionally, occupations that are full-time, have schedule flexibility, are also included in that demographic, and are more likely to sit often throughout their workday.

Ergonomics Policy Implementation:

Obstacles surrounding better ergonomic features to sedentary employees include cost, time, effort and for both companies and employees. The evidence above helps establish the importance of ergonomics in a sedentary workplace; however missing information from this problem is enforcement and policy implementation.  As a modernized workplace becomes more and more technology based more jobs are becoming primarily seated, therefore leading to a need to prevent chronic injuries and pain. This is becoming easier with the amount of research around ergonomic tools saving money companies by limiting the number of days missed from work and workers comp cases. The way to ensure that corporations prioritize these health outcomes for their employees is through policy and implementation.

Nationwide there are no policies that are currently in place, however a handful of big companies and states have taken on cultural policies to insure the safety of all workers.  For example, the state of Nevada risk management department has established a set of ground rules for both agencies responsibilities and employees responsibilities. The agency responsibilities include evaluating workstations, using risk management resources when necessary and keeping OSHA records. To see specific workstation ergonomic policies and responsibilities click here.

Methods

Until recently, methods used to evaluate human factors and ergonomics ranged from simple questionnaires to more complex and expensive usability labs. Some of the more common human factors methods are listed below:

• Ethnographic analysis: Using methods derived from ethnography, this process focuses on observing the uses of technology in a practical environment. It is a qualitative and observational method that focuses on "real-world" experience and pressures, and the usage of technology or environments in the workplace. The process is best used early in the design process.
• Focus Groups are another form of qualitative research in which one individual will facilitate discussion and elicit opinions about the technology or process under investigation. This can be on a one-to-one interview basis, or in a group session. Can be used to gain a large quantity of deep qualitative data, though due to the small sample size, can be subject to a higher degree of individual bias. Can be used at any point in the design process, as it is largely dependent on the exact questions to be pursued, and the structure of the group. Can be extremely costly.
• Iterative design: Also known as prototyping, the iterative design process seeks to involve users at several stages of design, to correct problems as they emerge. As prototypes emerge from the design process, these are subjected to other forms of analysis as outlined in this article, and the results are then taken and incorporated into the new design. Trends among users are analyzed, and products redesigned. This can become a costly process, and needs to be done as soon as possible in the design process before designs become too concrete.
• Meta-analysis: A supplementary technique used to examine a wide body of already existing data or literature to derive trends or form hypotheses to aid design decisions. As part of a literature survey, a meta-analysis can be performed to discern a collective trend from individual variables.
• Subjects-in-tandem: Two subjects are asked to work concurrently on a series of tasks while vocalizing their analytical observations. The technique is also known as "Co-Discovery" as participants tend to feed off of each other's comments to generate a richer set of observations than is often possible with the participants separately. This is observed by the researcher, and can be used to discover usability difficulties. This process is usually recorded.
• Surveys and questionnaires: A commonly used technique outside of human factors as well, surveys and questionnaires have an advantage in that they can be administered to a large group of people for relatively low cost, enabling the researcher to gain a large amount of data. The validity of the data obtained is, however, always in question, as the questions must be written and interpreted correctly, and are, by definition, subjective. Those who actually respond are in effect self-selecting as well, widening the gap between the sample and the population further.
• Task analysis: A process with roots in activity theory, task analysis is a way of systematically describing human interaction with a system or process to understand how to match the demands of the system or process to human capabilities. The complexity of this process is generally proportional to the complexity of the task being analyzed, and so can vary in cost and time involvement. It is a qualitative and observational process. Best used early in the design process.
• Think aloud protocol: Also known as "concurrent verbal protocol", this is the process of asking a user to execute a series of tasks or use technology, while continuously verbalizing their thoughts so that a researcher can gain insights as to the users' analytical process. Can be useful for finding design flaws that do not affect task performance, but may have a negative cognitive effect on the user. Also useful for utilizing experts to better understand procedural knowledge of the task in question. Less expensive than focus groups, but tends to be more specific and subjective.
• User analysis: This process is based around designing for the attributes of the intended user or operator, establishing the characteristics that define them, creating a persona for the user. Best done at the outset of the design process, a user analysis will attempt to predict the most common users, and the characteristics that they would be assumed to have in common. This can be problematic if the design concept does not match the actual user, or if the identified are too vague to make clear design decisions from. This process is, however, usually quite inexpensive, and commonly used.
• "Wizard of Oz": This is a comparatively uncommon technique but has seen some use in mobile devices. Based upon the Wizard of Oz experiment, this technique involves an operator who remotely controls the operation of a device to imitate the response of an actual computer program. It has the advantage of producing a highly changeable set of reactions, but can be quite costly and difficult to undertake.
• Methods analysis is the process of studying the tasks a worker completes using a step-by-step investigation. Each task in broken down into smaller steps until each motion the worker performs is described. Doing so enables you to see exactly where repetitive or straining tasks occur.
• Time studies determine the time required for a worker to complete each task. Time studies are often used to analyze cyclical jobs. They are considered "event based" studies because time measurements are triggered by the occurrence of predetermined events.
• Work sampling is a method in which the job is sampled at random intervals to determine the proportion of total time spent on a particular task. It provides insight into how often workers are performing tasks which might cause strain on their bodies.
• Predetermined time systems are methods for analyzing the time spent by workers on a particular task. One of the most widely used predetermined time system is called Methods-Time-Measurement (MTM). Other common work measurement systems include MODAPTS and MOST. Industry specific applications based on PTS are Seweasy,MODAPTS and GSD as seen in paper: Miller, Doug, Towards Sustainable Labour Costing in UK Fashion Retail (5 February 2013). Available at SSRN: http://ssrn.com/abstract=2212100 or doi:10.2139/ssrn.2212100 .
• Cognitive walkthrough: This method is a usability inspection method in which the evaluators can apply user perspective to task scenarios to identify design problems. As applied to macroergonomics, evaluators are able to analyze the usability of work system designs to identify how well a work system is organized and how well the workflow is integrated.
• Kansei method: This is a method that transforms consumer's responses to new products into design specifications. As applied to macroergonomics, this method can translate employee's responses to changes to a work system into design specifications.
• High Integration of Technology, Organization, and People (HITOP): This is a manual procedure done step-by-step to apply technological change to the workplace. It allows managers to be more aware of the human and organizational aspects of their technology plans, allowing them to efficiently integrate technology in these contexts.
• Top modeler: This model helps manufacturing companies identify the organizational changes needed when new technologies are being considered for their process.
• Computer-integrated Manufacturing, Organization, and People System Design (CIMOP): This model allows for evaluating computer-integrated manufacturing, organization, and people system design based on knowledge of the system.
• Anthropotechnology: This method considers analysis and design modification of systems for the efficient transfer of technology from one culture to another.
• Systems analysis tool (SAT): This is a method to conduct systematic trade-off evaluations of work-system intervention alternatives.
• Macroergonomic analysis of structure (MAS): This method analyzes the structure of work systems according to their compatibility with unique sociotechnical aspects.
• Macroergonomic analysis and design (MEAD): This method assesses work-system processes by using a ten-step process.
• Virtual manufacturing and response surface methodology (VMRSM): This method uses computerized tools and statistical analysis for workstation design.

Weaknesses

Problems related to measures of usability include the fact that measures of learning and retention of how to use an interface are rarely employed and some studies treat measures of how users interact with interfaces as synonymous with quality-in-use, despite an unclear relation.

Although field methods can be extremely useful because they are conducted in the users' natural environment, they have some major limitations to consider. The limitations include:

1. Usually take more time and resources than other methods
2. Very high effort in planning, recruiting, and executing compared with other methods
3. Much longer study periods and therefore requires much goodwill among the participants
4. Studies are longitudinal in nature, therefore, attrition can become a problem.