Thallium is a chemical element with symbol Tl and atomic number 81. It is a gray post-transition metal, not found free in nature; when isolated, thallium discolors when exposed to air. Chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861, in residues of sulfuric acid production. Both used the newly developed method of flame spectroscopy, in which thallium produces a notable green spectral line. Thallium, from Greek θαλλός, thallós, meaning "a green twig", was named by Crookes, it was isolated by both Lamy and Crookes in 1862. Crookes exhibited it as a powder precipitated by zinc at the International exhibition, which opened on 1 May that year. Thallium tends to oxidize to the +1 oxidation states as ionic salts; the +3 state resembles that of the other elements in group 13. However, the +1 state, far more prominent in thallium than the elements above it, recalls the chemistry of alkali metals, thallium ions are found geologically in potassium-based ores, are handled in many ways like potassium ions by ion pumps in living cells.
Commercially, thallium is produced not from potassium ores, but as a byproduct from refining of heavy-metal sulfide ores. 60–70% of thallium production is used in the electronics industry, the remainder is used in the pharmaceutical industry and in glass manufacturing. It is used in infrared detectors; the radioisotope thallium-201 is used in small, nontoxic amounts as an agent in a nuclear medicine scan, during one type of nuclear cardiac stress test. Soluble thallium salts are toxic, they were used in rat poisons and insecticides. Use of these compounds has been restricted or banned in many countries, because of their nonselective toxicity. Thallium poisoning results in hair loss, although this characteristic symptom does not always surface; because of its historic popularity as a murder weapon, thallium has gained notoriety as "the poisoner's poison" and "inheritance powder". A thallium atom has 81 electrons, arranged in the electron configuration 4f145d106s26p1. Due to the inert pair effect, the 6s electron pair is relativistically stabilised and it is more difficult to get them involved in chemical bonding than for the heavier elements.
Thus few electrons are available for metallic bonding, similar to the neighboring elements mercury and lead, hence thallium, like its congeners, is a soft electrically conducting metal with a low melting point of 304 °C. A number of standard electrode potentials, depending on the reaction under study, are reported for thallium, reflecting the decreased stability of the +3 oxidation state: Thallium is the first element in group 13 where the reduction of the +3 oxidation state to the +1 oxidation state is spontaneous under standard conditions. Since bond energies decrease down the group, with thallium, the energy released in forming two additional bonds and attaining the +3 state is not always enough to outweigh the energy needed to involve the 6s-electrons. Accordingly, thallium oxide and hydroxide are more basic and thallium oxide and hydroxide are more acidic, showing that thallium conforms to the general rule of elements being more electropositive in their lower oxidation states. Thallium is sectile enough to be cut with a knife at room temperature.
It has a metallic luster that, when exposed to air tarnishes to a bluish-gray tinge, resembling lead. It may be preserved by immersion in oil. A heavy layer of oxide builds up on thallium. In the presence of water, thallium hydroxide is formed. Sulfuric and nitric acids dissolve thallium to make the sulfate and nitrate salts, while hydrochloric acid forms an insoluble thallium chloride layer. Thallium has 25 isotopes which have atomic masses that range from 184 to 210. 203Tl and 205Tl make up nearly all of natural thallium. 204Tl is the most stable radioisotope, with a half-life of 3.78 years. It is made by the neutron activation of stable thallium in a nuclear reactor; the most useful radioisotope, 201Tl, decays by electron capture, emitting X-rays, photons of 135 and 167 keV in 10% total abundance. It is the most popular isotope used for thallium nuclear cardiac stress tests. Thallium compounds resemble the corresponding aluminium compounds, they are moderately strong oxidizing agents and are unstable, as illustrated by the positive reduction potential for the Tl3+/Tl couple.
Some mixed-valence compounds are known, such as Tl4O3 and TlCl2, which contain both thallium and thallium. Thallium oxide, Tl2O3, is a black solid which decomposes above 800 °C, forming the thallium oxide and oxygen; the simplest possible thallium compound, thallane, is too unstable to exist in bulk, both due to the instability of the +3 oxidation state as well as poor overlap of the valence 6s and 6p orbitals of thallium with the 1s orbital of hydrogen. The trihalides are more stable, although they are chemically distinct from those of the lighter group 13 elements and are still the least stable in the whole group. For instance, thallium fluoride, TlF3, has the β-BiF3 structure rather than that of the lighter group 13 trifluorides, does not form the TlF−4 complex anion in aqueous solution; the trichloride and tribromide disproportionate just above room
A fire sprinkler or sprinkler head is the component of a fire sprinkler system that discharges water when the effects of a fire have been detected, such as when a predetermined temperature has been exceeded. Fire sprinklers are extensively used worldwide, with over 40 million sprinkler heads fitted each year. In buildings protected by properly designed and maintained fire sprinklers, over 99% of fires were controlled by fire sprinklers alone. In 1812, British inventor Sir William Congreve patented a manual sprinkler system using perforated pipes along the ceiling; when someone noticed a fire, a valve outside the building could be opened to send water through the pipes. It was not until a short time that, as a result of a large furniture factory that burned down, Hiram Stevens Maxim was consulted on how to prevent a recurrence and invented the first automatic fire sprinkler, it would report the fire to the fire station. Maxim was unable to sell the idea elsewhere. Henry S. Parmalee of New Haven, Connecticut created and installed the first automatic fire sprinkler system in 1874, using solder that melted in a fire to unplug holes in the otherwise sealed water pipes.
He was the president of Mathusek Piano Works, invented his sprinkler system in response to exorbitantly high insurance rates. Parmalee patented his idea and had great success with it in the U. S. calling his invention the "automatic fire extinguisher". He traveled to Europe to demonstrate his method to stop a building fire before total destruction. Parmalee's invention did not get as much attention as he had planned, as most people could not afford to install a sprinkler system. Once he realized this, he turned his efforts to educating insurance companies about his system, he explained that the sprinkler system would reduce the loss ratio, thus save money for the insurance companies. He knew that he could never succeed in obtaining contracts from the business owners to install his system unless he could ensure for them a reasonable return in the form of reduced premiums. In this connection, he was able to enlist the interest of two men, who both had connections in the insurance industry; the first of was Major Hesketh, a cotton spinner in a large business in Bolton, Chairman of the Bolton Cotton Trades Mutual Insurance Company.
The Directors of this Company and its Secretary, Peter Kevan, took an interest in Parmalee’s early experiments. Hesketh got Parmalee his first order for sprinkler installations in the cotton spinning mills of John Stones & Company, at Astley Bridge, Bolton; this was followed soon afterwards by an order from the Alexandra Mills, owned by John Butler of the same town. Although Parmalee got two sales through its efforts, the Bolton Cotton Trades Mutual Insurance Company was not a big company outside of its local area. Parmalee needed a wider influence, he found this influence in James North Lane, the Manager of the Mutual Fire Insurance Corporation of Manchester. This company was founded in 1870 by the Textile Manufacturers' Associations of Lancashire and Yorkshire as a protest against high insurance rates, they had a policy of encouraging risk management and more the use of the most up-to-date and scientific apparatus for extinguishing fires. Though he put tremendous effort and time into educating the masses on his sprinkler system, by 1883 only about 10 factories were protected by the Parmalee sprinkler.
Back in the U. S. Frederick Grinnell, manufacturing the Parmalee sprinkler, designed the more effective Grinnell sprinkler, he increased sensitivity by removing the fusible joint from all contact with the water, and, by seating a valve in the center of a flexible diaphragm, he relieved the low-fusing soldered joint of the strain of water pressure. By this means, the valve seat was forced against the valve by the water pressure, producing a self-closing action; the greater the water pressure, the tighter the valve. The flexible diaphragm had a more important function, it caused the valve and its seat to move outwards until the solder joint was severed. Grinnell got a patent for his version of the sprinkler system, he took his invention to Europe, where it was a much bigger success than the Parmalee version. The Parmalee system was withdrawn, opening the path for Grinnell and his invention. Fire sprinkler application and installation guidelines, overall fire sprinkler system design guidelines are provided by the National Fire Protection Association 13, 13D, 13R.
California and Illinois require sprinklers in at least some new residential construction. Fire sprinklers can be open orifice. Automatic fire sprinklers operate at a predetermined temperature, utilizing a fusible element, a portion of which melts, or a frangible glass bulb containing liquid which breaks, allowing the plug in the orifice to be pushed out of the orifice by the water pressure in the fire sprinkler piping, resulting in water flow from the orifice; the water stream impacts a deflector, which produces a specific spray pattern designed in support of the goals of the sprinkler type. Modern sprinkler heads are designed to direct spray downwards. Spray nozzles are available to provide spray in various patterns; the majority of automatic fire sprinklers operate individually in a fire. Contrary to motion picture representation, the entire sprinkler system does not activate, unless the system is a special deluge type. Open orifice sprinklers are only used in water spray systems or deluge sprinklers systems.
They are identical to the automatic sprinkler on which they are based, with the heat-sensitive operating element removed. Automa
John Wiley & Sons, Inc. branded as Wiley in recent years, is a global publishing company that specializes in academic publishing and instructional materials. The company produces books and encyclopedias, in print and electronically, as well as online products and services, training materials, educational materials for undergraduate and continuing education students. Founded in 1807, Wiley is known for publishing the For Dummies book series. In 2017, the company had a revenue of $1.7 billion. Wiley was established in 1807; the company was the publisher of such 19th century American literary figures as James Fenimore Cooper, Washington Irving, Herman Melville, Edgar Allan Poe, as well as of legal and other non-fiction titles. Wiley worked in partnership with Cornelius Van Winkle, George Long, George Palmer Putnam, Robert Halsted; the firm took its current name in 1865. Wiley shifted its focus to scientific and engineering subject areas, abandoning its literary interests. Charles Wiley's son John took over the business when his father died in 1826.
The firm was successively named Wiley, Lane & Co. Wiley & Putnam, John Wiley; the company acquired its present name in 1876, when John's second son William H. Wiley joined his brother Charles in the business. Through the 20th century, the company expanded its publishing activities, the sciences, higher education. Since the establishment of the Nobel Prize in 1901, Wiley and its acquired companies have published the works of more than 450 Nobel Laureates, in every category in which the prize is awarded. One of the world's oldest independent publishing companies, Wiley marked its bicentennial in 2007 with a year-long celebration, hosting festivities that spanned four continents and ten countries and included such highlights as ringing the closing bell at the New York Stock Exchange on May 1. In conjunction with the anniversary, the company published Knowledge for Generations: Wiley and the Global Publishing Industry, 1807-2007, depicting Wiley's pivotal role in the evolution of publishing against a social and economic backdrop.
Wiley has created an online community called Wiley Living History, offering excerpts from Knowledge for Generations and a forum for visitors and Wiley employees to post their comments and anecdotes. In December 2010, Wiley opened an office in Dubai; the company has had an office in Beijing, since 2001, China is now its sixth-largest market for STEM content. Wiley established publishing operations in India in 2006, has established a presence in North Africa through sales contracts with academic institutions in Tunisia and Egypt. On April 16, 2012, the company announced the establishment of Wiley Brasil Editora LTDA in São Paulo, effective May 1, 2012. Wiley's scientific and medical business was expanded by the acquisition of Blackwell Publishing in February 2007; the combined business, named Scientific, Technical and Scholarly, publishes, in print and online, 1,400 scholarly peer-reviewed journals and an extensive collection of books, major reference works and laboratory manuals in the life and physical sciences and allied health, the humanities, the social sciences.
Through a backfile initiative completed in 2007, 8.2 million pages of journal content have been made available online, a collection dating back to 1799. Wiley-Blackwell publishes on behalf of about 700 professional and scholarly societies. Other major journals published include Angewandte Chemie, Advanced Materials, International Finance and Liver Transplantation. Launched commercially in 1999, Wiley InterScience provided online access to Wiley journals, major reference works, books, including backfile content. Journals from Blackwell Publishing were available online from Blackwell Synergy until they were integrated into Wiley InterScience on June 30, 2008. In December 2007, Wiley began distributing its technical titles through the Safari Books Online e-reference service. On February 17, 2012, Wiley announced the acquisition of Inscape Holdings Inc. which provides DISC assessments and training for interpersonal business skills. Wiley described the acquisition as complementary to the workplace learning products published under its Pfeiffer imprint, one that would help Wiley advance its digital delivery strategy and extend its global reach through Inscape's international distributor network.
On March 7, 2012, Wiley announced its intention to divest assets in the areas of travel, general interest, nautical and crafts, as well as the Webster's New World and CliffsNotes brands. The planned divestiture was aligned with Wiley's "increased strategic focus on content and services for research and professional practices, on lifelong learning through digital technology". On August 13, 2012, Wiley announced it entered into a definitive agreement to sell all of its travel assets, including all of its interests in the Frommer's brand, to Google Inc. On November 6, 2012, Houghton Mifflin Harcourt acquired Wiley's cookbooks and study guides. In 2013, Wiley sold its pets and general interest lines to Turner Publishing Company and its nautical line to Fernhurst Books. H
Sheet metal is metal formed by an industrial process into thin, flat pieces. Sheet metal is one of the fundamental forms used in metalworking and it can be cut and bent into a variety of shapes. Countless everyday objects are fabricated from sheet metal. Thicknesses can vary significantly. Sheet metal is available in coiled strips; the coils are formed by running a continuous sheet of metal through a roll slitter. In most of the world, sheet metal thickness is specified in millimeters. In the US, the thickness of sheet metal is specified by a traditional, non-linear measure known as its gauge; the larger the gauge number, the thinner the metal. Used steel sheet metal ranges from 30 gauge to about 7 gauge. Gauge differs between nonferrous metals such as aluminum or copper. Copper thickness, for example, is measured in ounces. Parts manufactured from sheet metal must maintain a uniform thickness for ideal results. There are many different metals that can be made into sheet metal, such as aluminium, copper, tin and titanium.
For decorative uses, some important sheet metals include silver and platinum Sheet metal is used in automobile and truck bodies, airplane fuselages and wings, medical tables, roofs for buildings and many other applications. Sheet metal of iron and other materials with high magnetic permeability known as laminated steel cores, has applications in transformers and electric machines. An important use of sheet metal was in plate armor worn by cavalry, sheet metal continues to have many decorative uses, including in horse tack. Sheet metal workers are known as "tin bashers", a name derived from the hammering of panel seams when installing tin roofs. Hand-hammered metal sheets have been used since ancient times for architectural purposes. Water-powered rolling mills replaced the manual process in the late 17th century; the process of flattening metal sheets required large rotating iron cylinders which pressed metal pieces into sheets. The metals suited for this were lead, zinc and steel. Tin was used to coat iron and steel sheets to prevent it from rusting.
This tin-coated sheet metal was called "tinplate." Sheet metals appeared in the United States in the 1870s, being used for shingle roofing, stamped ornamental ceilings and exterior facades. Sheet metal ceilings were only popularly known as "tin ceilings" as manufacturers of the period did not use the term; the popularity of both shingles and ceilings encouraged widespread production. With further advances of steel sheet metal production in the 1890s, the promise of being cheap, easy to install and fireproof gave the middle-class a significant appetite for sheet metal products, it was not until the 1930s and WWII that metals became scarce and the sheet metal industry began to collapse. However, some American companies, such as the W. F. Norman Corporation, were able to stay in business by making other products until Historic preservation projects aided the revival of ornamental sheet metal. Grade 304 is the most common of the three grades, it offers good corrosion resistance while maintaining weldability.
Available finishes are #2B, #3, #4. Grade 303 is not available in sheet form. Grade 316 possesses more corrosion resistance and strength at elevated temperatures than 304, it is used for pumps, chemical equipment, marine applications. Available finishes are #2B, #3, #4. Grade 410 is a heat treatable stainless steel, but it has a lower corrosion resistance than the other grades, it is used in cutlery. The only available finish is dull. Grade 430 is popular grade, low cost alternative to series 300's grades; this is used. Common grade for appliance products with a brushed finish. Aluminum is a popular metal used in sheet metal due to its flexibility, wide range of options, cost effectiveness, other properties; the four most common aluminium grades available as sheet metal are 1100-H14, 3003-H14, 5052-H32, 6061-T6. Grade 1100-H14 is commercially pure aluminium chemical and weather resistant, it has low strength. It is used in chemical processing equipment, light reflectors, jewelry. Grade 3003-H14 is stronger than 1100, while maintaining the same low cost.
It is corrosion weldable. It is used in stampings and drawn parts, mail boxes, cabinets and fan blades. Grade 5052-H32 is much stronger than 3003, it maintains weldability. Common applications include electronic chassis and pressure vessels. Grade 6061-T6 is a common heat-treated structural aluminium alloy, it is weldable, corrosion resistant, stronger than 5052, but not as formable. It loses some of its strength, it is used in modern aircraft structures. Brass is an alloy of copper, used as a sheet metal, it has more strength, corrosion resistance and formability when compared to copper while retaining its conductivity. In sheet hydroforming, variation in incoming sheet coil properties is a common problem for forming process with materials for automotive applications. Though incoming sheet coil may meet tensile test specifications, high rejection rate is ofte
Gallium is a chemical element with symbol Ga and atomic number 31. It is in group 13 of the periodic table, thus has similarities to the other metals of the group, aluminium and thallium. Gallium does not occur as a free element in nature, but as gallium compounds in trace amounts in zinc ores and in bauxite. Elemental gallium is a soft, silvery blue metal at standard temperature and pressure, a brittle solid at low temperatures, a liquid at temperatures greater than 29.76 °C. The melting point of gallium is used as a temperature reference point. Gallium alloys are used in thermometers as a non-toxic and environmentally friendly alternative to mercury, can withstand higher temperatures than mercury; the alloy galinstan has an lower melting point of −19 °C, well below the freezing point of water. Since its discovery in 1875, gallium has been used to make alloys with low melting points, it is used in semiconductors as a dopant in semiconductor substrates. Gallium is predominantly used in electronics.
Gallium arsenide, the primary chemical compound of gallium in electronics, is used in microwave circuits, high-speed switching circuits, infrared circuits. Semiconducting gallium nitride and indium gallium nitride produce blue and violet light-emitting diodes and diode lasers. Gallium is used in the production of artificial gadolinium gallium garnet for jewelry. Gallium is considered a technology-critical element. Gallium has no known natural role in biology. Gallium behaves in a similar manner to ferric salts in biological systems and has been used in some medical applications, including pharmaceuticals and radiopharmaceuticals. Elemental gallium is not found in nature, but it is obtained by smelting. Pure gallium metal has a silvery color and its solid metal fractures conchoidally like glass. Gallium liquid expands by 3.10 %. Gallium shares the higher-density liquid state with a short list of other materials that includes water, germanium, antimony and plutonium. Gallium attacks most other metals by diffusing into the metal lattice.
For example, it diffuses into the grain boundaries of aluminium-zinc alloys and steel, making them brittle. Gallium alloys with many metals, is used in small quantities in the plutonium-gallium alloy in the plutonium cores of nuclear bombs to stabilize the plutonium crystal structure; the melting point of gallium, at 302.9146 K, is just above room temperature, is the same as the average summer daytime temperatures in Earth's mid-latitudes. This melting point is one of the formal temperature reference points in the International Temperature Scale of 1990 established by the International Bureau of Weights and Measures; the triple point of gallium, 302.9166 K, is used by the US National Institute of Standards and Technology in preference to the melting point. The melting point of gallium allows it to melt in the human hand, refreeze if removed; the liquid metal has a strong tendency to supercool below its melting point/freezing point: Ga nanoparticles can be kept in the liquid state below 90 K. Seeding with a crystal helps to initiate freezing.
Gallium is one of the four non-radioactive metals that are known to be liquid at, or near, normal room temperature. Of the four, gallium is the only one, neither reactive nor toxic and can therefore be used in metal-in-glass high-temperature thermometers, it is notable for having one of the largest liquid ranges for a metal, for having a low vapor pressure at high temperatures. Gallium's boiling point, 2673 K, is more than eight times higher than its melting point on the absolute scale, the greatest ratio between melting point and boiling point of any element. Unlike mercury, liquid gallium metal wets glass and skin, along with most other materials, making it mechanically more difficult to handle though it is less toxic and requires far fewer precautions. Gallium painted onto glass is a brilliant mirror. For this reason as well as the metal contamination and freezing-expansion problems, samples of gallium metal are supplied in polyethylene packets within other containers. Gallium does not crystallize in any of the simple crystal structures.
The stable phase under normal conditions is orthorhombic with 8 atoms in the conventional unit cell. Within a unit cell, each atom has only one nearest neighbor; the remaining six unit cell neighbors are spaced 27, 30 and 39 pm farther away, they are grouped in pairs with the same distance. Many stable and metastable phases are found as function of pressure; the bonding between the two nearest neighbors is covalent. This explains the low melting point relative to the neighbor elements and indium; this structure is strikingly similar to that of iodine and forms because of interactions between the single 4p electrons of gallium atoms, further away from the nucleus than the 4s electrons and the 3d10 core. This phenomenon recurs with mercury with its "pseudo-noble-gas" 4f145d106s2 electron configuration, liquid at room temperature; the 3d10 electrons do not shield the outer electrons well from the nucleus an
Indium is a chemical element with symbol In and atomic number 49. It is a post-transition metal. Soft and malleable, indium has a melting point higher than sodium and gallium, but lower than lithium and tin. Chemically, indium is similar to gallium and thallium, it is intermediate between the two in terms of its properties. Indium was discovered in 1863 by Ferdinand Reich and Hieronymous Theodor Richter by spectroscopic methods, they named it for the indigo blue line in its spectrum. Indium was isolated the next year. Indium is produced as a byproduct of zinc refinement, it is most notably used in the semiconductor industry, in low-melting-point metal alloys such as solders, in soft-metal high-vacuum seals, in the production of transparent conductive coatings of indium tin oxide on glass. Indium is considered a technology-critical element. Indium has no biological role, though its compounds are somewhat toxic when injected into the bloodstream. Most occupational exposure is through ingestion, from which indium compounds are not absorbed well, inhalation, from which they are moderately absorbed.
Indium is a silvery-white ductile post-transition metal with a bright luster. It is so soft, it leaves a visible line on paper. It is a member of group 13 on the periodic table and its properties are intermediate between its vertical neighbours gallium and thallium. Like tin, a high-pitched cry is heard when indium is bent – a crackling sound due to crystal twinning. Like gallium, indium is able to wet glass. Like both, indium has a low melting point, 156.60 °C. The boiling point is 2072 °C, higher than that of thallium, but lower than gallium, conversely to the general trend of melting points, but to the trends down the other post-transition metal groups because of the weakness of the metallic bonding with few electrons delocalized; the density of indium, 7.31 g/cm3, is greater than gallium, but lower than thallium. Below the critical temperature, 3.41 K, indium becomes a superconductor. Indium crystallizes in the body-centered tetragonal crystal system in the space group I4/mmm: this is a distorted face-centered cubic structure, where each indium atom has four neighbours at 324 pm distance and eight neighbours further.
Indium has greater solubility in liquid mercury than any other metal. Indium displays a ductile viscoplastic response, found to be size-independent in tension and compression; however it does have a size effect in bending and indentation, associated to a length-scale of order 50–100 µm large when compared with other metals. Indium has 49 electrons, with an electronic configuration of 4d105s25p1. In compounds, indium most donates the three outermost electrons to become indium, In3+. In some cases, the pair of 5s-electrons are not donated, resulting in indium, In+; the stabilization of the monovalent state is attributed to the inert pair effect, in which relativistic effects stabilize the 5s-orbital, observed in heavier elements. Thallium shows an stronger effect, causing oxidation to thallium to be more probable than to thallium, whereas gallium shows only the +3 oxidation state. Thus, although thallium is a moderately strong oxidizing agent, indium is not, many indium compounds are powerful reducing agents.
While the energy required to include the s-electrons in chemical bonding is lowest for indium among the group 13 metals, bond energies decrease down the group so that by indium, the energy released in forming two additional bonds and attaining the +3 state is not always enough to outweigh the energy needed to involve the 5s-electrons. Indium oxide and hydroxide are more basic and indium oxide and hydroxide are more acidic. A number of standard electrode potentials, depending on the reaction under study, are reported for indium, reflecting the decreased stability of the +3 oxidation state: Indium metal does not react with water, but it is oxidized by stronger oxidizing agents such as halogens to give indium compounds, it does not form a boride, silicide, or carbide, the hydride InH3 has at best a transitory existence in ethereal solutions at low temperatures, being unstable enough to spontaneously polymerize without coordination. Indium is rather basic in aqueous solution, showing only slight amphoteric characteristics, unlike its lighter homologs aluminium and gallium, it is insoluble in aqueous alkaline solutions.
Indium has 39 known isotopes, ranging in mass number from 97 to 135. Only two isotopes occur as primordial nuclides: indium-113, the only stable isotope, indium-115, which has a half-life of 4.41×1014 years, four orders of magnitude greater than the age of the universe and nearly 30,000 times greater than that of natural thorium. The half-life of 115In is long because the beta decay to 115Sn is spin-forbidden. Indium-115 makes up 95.7% of all indium. Indium is one of three known elements of which the stable isotope is less abundant in nature than the long-lived primordial radioisotopes; the stablest artificial isotope is indium-111, with a half-life of 2.8 days. All other isotopes have half-lives shorter than 5 hours. Indium has 47 meta states, among which indium-114m1 is the most stable, more stable than the ground state of any indium
A gas explosion is an explosion resulting from mixing a gas from a gas leak, with air in the presence of an ignition source. In household accidents, the principal explosive gases are those used for heating or cooking purposes such as natural gas, propane, butane. In industrial explosions many other gases, like hydrogen, as well as evaporated gasoline /petrol or ethanol play an important role. Industrial gas explosions can be prevented with the use of intrinsic safety barriers to prevent ignition. Whether a mixture of air and gas is combustible depends on the air-to-fuel ratio. For each fuel, ignition occurs only within the explosive range. For example, for methane and gasoline vapor, the explosive range is 5-15% and 1.4-7.6% gas to air, respectively. The Pittsburgh gasometer explosion occurred during the morning of November 14, 1927 in the north side of Pittsburgh. A large gasometer exploded, injuring hundreds; the Mather Mine disaster occurred on May 1928 at 4:07 PM in Mather, Pennsylvania. A methane gas and dust explosion resulted in the deaths of 195 men.
The New London School explosion occurred on March 18, 1937, when a natural gas leak caused an explosion, destroying the New London School of the city of New London, Texas. The disaster killed three hundred teachers; the Cleveland East Ohio Gas Explosion occurred on the afternoon of Friday, October 20, 1944. The resulting gas leak and fires killed 130 people and destroyed a one square mile area on Cleveland, Ohio’s east side. On October 31, 1963, the Indianapolis Coliseum Explosion occurred during the opening night for the Holiday on Ice show, killing 74 and injuring nearly 400; the cause was an explosion following a propane tank leak. LaSalle Heights Disaster March 1, 1965. Gas line fractured in a low-cost residential neighborhood near Montreal, killing 28 people and injuring 39. Reading, January 9, 1968. An explosion demolished two houses. A gas company spokesman said Reading workmen digging in the street to repair a water main had hit a gas line shortly before the explosion; the Richmond, Indiana explosion, on Saturday, April 6, 1968.
Two explosions occur in the middle of downtown Richmond, Indiana. The first is caused by a natural gas leak, the second, by gunpowder and ammunition inside a sporting goods store. 41 people are killed and more than 150 injured. Four square blocks of downtown Richmond, are damaged by the explosion or subsequent fire. Ronan Point was a 23-story council tower block in Newham, east London. On 16 May 1968 a gas explosion caused the collapse of a whole corner of the building. Four people were killed in the collapse, with one dying of injuries. In April 8, 1970, a gas explosion that occurred during construction in Tenjimbashisuji Rokuchōme Station, Osaka Municipal Subway Tanimachi Line, Kita-ku, Japan, resulted in 79 persons dead, 420 persons injured and 495 houses and buildings burned and destroyed. Clarkston explosion on 21 October 1971, a build-up of gas under a shopping centre left 22 dead and around 100 injured. 23 October 1980, a propane explosion at Escuela Nacional de Marcelino Ugalde, Vizcaya, Spain.
According to the local government's official report, 50 schoolchildren and 3 adult were killed and an additional 128 persons injured. 23 May 1984 Abbeystead disaster - an explosion resulting in 16 deaths and 22 injured from Methane entering waterwork pipes. 24 March 1986 Loscoe gas explosion - no fatalities but extensive property destruction, this caused the UK Government to legislate on landfill sites and building practices with regard to landfill gas migration. In July 1988, 167 people died when Occidental Petroleum's Alpha offshore production platform, on the Piper field in the North Sea, exploded after a gas leak The 1989 Ufa train disaster was caused by a gas explosion from a leaking pipeline as two trains went by, their sparks igniting the gas. 575 people died. The 1992 explosion in Guadalajara, Mexico's second largest city, took place on April 22, 1992 in the downtown district of Analco. Numerous gasoline explosions in the sewer system over four hours destroyed kilometers of streets. 206 people were killed, nearly 500 injured and 15,000 were left homeless.
In April 28, 1995, Daegu Subway Line 1 Chapter 1-2 range interval is an explosion occurred on construction sites. The accident caused the accident area in the south west point Daegu Department Store Merchant grouting for new construction sites for drilling a 75mm hole drilling 31 drills by mistake by the city gas pipeline through the holes by punching the gas leak, near drain through a subway construction site been introduced into the explosion by fire of unknown cause is the one to buy. Of 50 m with an explosion of fire soared, killed 101 people, include 42 Dalseo Sangindong high school students, 202 people were injured in Sangindong, South Korea; the Humberto Vidal Explosion was a gas explosion that occurred on November 21, 1996, on the Humberto Vidal shoe store located in Río Piedras, Puerto Rico, United States. The explosion wounded 69 others when the building collapsed, it is considered one of the deadliest disasters to have occurred on the island. On December 11, 1998, there was a gas explosion in St. Cloud, which killed four people.
In December 1999, there was a natural gas explosion which destroyed one house and damaged four other houses in Larkhall, South Lanarkshire. It killed the family of four. Transco Gas who are r