Search Results - Iridium
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Iridium (pronounced /?'r?di?m/, i-RID-ee-?m) is the chemical element with atomic number 77, and is represented by the symbol Ir. A very hard, brittle, silvery-white transition metal of the platinum family, iridium is the second densest element (after osmium) and is the most corrosion-resistant metal, even at temperatures as high as 2000&_160;°C. Although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can even be flammable. The most important iridium compounds in terms of use are the salts and acids it forms with chlorine, though iridium also forms a number of organometallic compounds used in catalysis and in research. 191Ir and 193Ir are the only two naturally occurring isotopes of iridium as well as the only stable isotopes; the latter is the more abundant of the two. Iridium was discovered in 1803 by Smithson Tennant in London, England, among insoluble impurities in natural platinum from South America. Although it is one of the rarest elements in the Earth's crust, with annual production and consumption of only three tonnes, it has a number of specialized industrial and scientific applications. Iridium is employed when high corrosion resistance at high temperatures is needed, as in spark plugs, crucibles for recrystallization of semiconductors at high temperatures, electrodes for the production of chlorine in the chloralkali process, and radioisotope thermoelectric generators used in unmanned spacecraft. Iridium compounds also find applications as catalysts for the production of acetic acid. An unusually high abundance of iridium in a clay layer of the K–T geologic boundary was a crucial clue that led to the theory that the extinction of dinosaurs and many other species 65&_160;million years ago was caused by the impact of a massive extraterrestrial object—the so-called Alvarez hypothesis. Iridium is found in meteorites with an abundance much higher than its average abundance in the Earth's crust. It is thought that the amount of iridium in the planet Earth is much higher than that observed in crustal rocks, but because of the high density and tendency of iridium to bond with iron, most iridium descended below the crust and into the Earth's core when the planet was young and still molten. A member of the platinum group metals, iridium is white, resembling platinum, but with a slight yellowish cast. Due to its hardness, brittleness, and very high melting point (the tenth highest of all elements), solid iridium is difficult to machine, form, or work, and thus powder metallurgy is commonly employed instead.[2] It is the only metal to maintain good mechanical properties in air at temperatures above 1600&_160;°C.[3] Iridium has a very high boiling point (11th among all elements) and becomes a superconductor under 0.14&_160;K.[4]
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Showing 1 to 10 of 10 Articles matching 'Iridium' in related articles. |
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1. Palladium: The Unknown Precious Metal
October 01, 2009
Palladium: The Mystery Precious MetalPalladium is a precious metal that's approximately thirty times rarer than gold. It's a naturally white metal which has a luster like the better known precious metal platinum. It is proof against taint and extreme heat. It's a member of the platinum group metals ( PGM ), a group which also includes platinum, osmium, rhodium, ruthenium, and iridium. Though palladium should not be confused with platinum, another member of the platinum metals group. Locations of palladium mines are few, with the biggest, most productive mines being in the Bushveld Igneous ... (read more)
Author: Chuck Edwards
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2. Rent A Satellite Cell Phone For Connection In Remote Places
August 26, 2009
Who could make use of a satellite phone?
Do you go on holiday to remote areas for example hunting or fishing? Or does your occupation bring you to areas that were hit by emergency? In both cases you might end up in places where your cellular phone does not work. Some areas are simply too remote for wireless phone coverage. However, you still want to be able to call home or make an urgent call. You do not want to be trapped in the wilderness without a helpline! In that case you could rent a satellite phone.
What is the most important benefit?
Iridium satellite cell phones have on... (read more)
Author: Audrey M
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3. Remembering Record Industry Pioneer Les Paul
August 14, 2009
In this Feb. 26, 2007 file photo, guitar legend Les Paul performs at the Iridium Jazz Club in New YorkGuitar legend and recording industry pioneer Les Paul died on Thursday, August 13, at a hospital in White Plains, New York, of complications from pneumonia. He was 94 years old. Known for his virtuosity on guitar, Paul made breakthrough discoveries that forever changed the sound of popular music. Les Paul single-handedly changed the course of music when he developed his solid body guitar, and discovered a new way to record voices and instruments. Paul became known as the "Wizard of Wa... (read more)
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4. Legendary Guitarist, Inventor Les Paul Dies
August 13, 2009
Les Paul warms up with his quartet before a performance at the Iridium Jazz Club in New York City Legendary inventor, guitar player and recording artist Les Paul has died from complications from pneumonia. He was 94 years old.Paul revolutionized the music scene with his solid-body electric guitar that he first built in the 1940s in his quest for a guitar with amplified sound. In 1952, Gibson Guitar company began production of the Les Paul guitar.In an interview with Voice of America in 2007, Paul said he did not realize he was being a pioneer at the time, but did know that the "par... (read more)
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5. Tungsten as Wedding Rings
May 19, 2009
There are many kinds of precious metals used today in jewelry. These include gold, silver, platinum and palladium. Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is most widely traded. Other than these metals, one of the most popular types of precious metal currently used today in jewelry, particularly with wedding rings, is tungsten. So what is tungsten? Tungsten
Before the availability of tungsten jewelry, tungsten was first used for industrial means. It’s known to have the highest melting point ... (read more)
Author: Christopher Thomson
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6. Climate Satellite Launch Fails, Spacecraft Falls to Earth
February 24, 2009
A NASA mission intended to monitor global carbon dioxide emissions
suffered a setback Tuesday when a rocket carrying a satellite did not
reach orbit.Image provided by NASA shows artist concept of Iridium satellite in earth's orbitAn official with the company that built the
satellite, John Brunschwyler of Orbital Sciences Corporation, told a
news conference Tuesday that the rocket landed in the ocean near
Antarctica. He called it a "huge disappointment for the science
community."NASA says the covering that was over the satellite to
protect it during launch did not come off as planned. The add... (read more)
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7. How Banking Instrument And Hard Asset Lending Programs Work
November 14, 2008
Lending programs were developed to assist clients with either financial instruments (BGs, MTNs, LOCs, CMOs, Insurance Wraps, Treasury Notes, Stock Portfolios and other financial assets) or hard assets (emeralds, rubies, diamonds, gold, silver, copper isotopes, iridium, gold dust, real estate and other assets) to free up a rather frozen, long term asset into immediate cash enabling higher return, short term investments.
The only real requirement is that the asset be assigned and lien-able securing the lenders position.
Most program loans range from fifty million (50,000,000.00) to ... (read more)
Author: marcel ford
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8. Oakley Sunglasses - Perfectly Made for Your Eyes
April 09, 2008
Oakley sunglasses have a class of their own. They have a long history. What was started in 1975 has now become a fashion statement. Oakleys have found their way into popular Hollywood movies. Many celebrities including film stars and sportspersons are their regular customers. So a question arises why Oakleys sunglasses are different from others.
These sunglasses have Plutonite and Iridium lens coatings, the do-it-yourself custom-made glasses and the mind-boggling Thump MP3 sunglasses. This lense material can filter out 100% of all UVA, UVB and UVC. The Oakley Plutonite lens also blocks 10... (read more)
Author: Peter Anthony
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9. How Plant-Eating Dinosaurs Nearly Destroyed the Earth
May 05, 2006
I've always been an amateur naturalist, and always wondered (nerd that I am) what actually killed the dinosaurs 65 million years ago. An entire order of animals was wiped out, the world over -- not one species in any size or ecological category survived. That's incredible. Circa 1980, a scientist name Alvarez advanced the hypothesis that an asteroid killed the dinosaurs. An asteroid did strike the planet 65 million years ago, and iridium in the soil strata is consistent with that fact. The Alvarez theory became a 'darling' of the science establishment and has since been pretty well embraced. I... (read more)
Author: RA Rawlins
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10. Venezuela Searches for Missing Radioactive Capsule
December 20, 2005
Venezuelan officials are conducting an urgent national search for a container with highly radioactive material that was stolen Sunday night.
The container of Iridium-192, was being carried in a light truck in the Yaracuy state when the truck was stolen.
Government officials have gone on Venezuelan television and radio, pleading with the thieves to return the container which is about the size of a lunch box because the material inside is potentially lethal.
They also said they are working on the assumption that the target of the theft was the truck, not its cargo, and that the thieves have no ... (read more)
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