Sunday, March 29, 2009
Japan's National Institute of Advanced Industrial Science and Technology (AIST) developed a deep UV LED with the purpose of diamond semiconductor.
AIST plans to reveal the details at the 56th Spring Meeting, 2009 of the Japan Society of Applied Physics, which will take place from March 30 to April 2, 2009, in Ibaraki Prefecture, Japan.
The deep UV LED is collected of a 2mm-square diamond substrate on which a p-i-n-structured diamond semiconductor is stacked. It emits deep ultraviolet light with an emanation wavelength of 235nm. The output is 30μW when a 320mA current is supplied.
"The LED is very close to practical use," said Satoshi Yamasaki, major research scientist of the Energy Technology Research Institute of AIST and a professor at Graduate School of Pure and Applied Sciences at University of Tsukuba.
According to AIST, the new LED has two most important characteristics. First, its glowing efficiency continues to increase even when a large current is supplied. Second, it has an outstanding resistance to high temperatures.
Specially, when a current with a density exceeding 2,000A/cm2 is applied through an electrode with a diameter of 120μm, the luminous efficiency continues to increase without being saturated, according to AIST. At present, the operating current density of a deep UV LED using AlGaN-based semiconductors, which may equal the new LED, is only 500A/cm2 at a maximum, AIST said.
In view to the excellent heat resistance, even when temperature rises from room temperature to 420°C, the light emission intensity does not degrade but continues to increase, AIST said.
Unlike general LEDs, the diamond LED emits light because of the creation of "excitons." An exciton is an electron-hole pair that behaves like a kind of particle. In general, it is susceptible to heat and often deteriorates quickly.
Though, the excitons generated in the diamond LED are "very stable and will not break until 600°C," said Toshiharu Makino, researcher of the Energy Enabling Technology Group at the Energy Technology Research Institute of AIST. This is the main reason for the excellent high-temperature resistance.
posted by Tamil Nadu ,Tamilnadu Government,Places,Wild Life,Hill Stations,Temples,Sports,Accomodation,Cusine,Fine Art @ 10:29 PM
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Thursday, March 19, 2009
Lucara Diamond Corp. and Motapa Diamonds Inc., is a joint venture partners on one particular project and this came out to the public on Tuesday in order to form merged company focused on Africa. Lucara is a member of the Lundin group of companies and it stated that its main target/aim is to assemble a portfolio of projects which enable it to become a leading mid-tier African diamond manufacturer.
William Lamb who is general manager of Lucara stated that in order to create an added value this business amalgamation is an excellent opportunity and also establishes a focused, strategic platform for further expansion in Africa.
This is the correct time to consolidate Mothae and make larger more assessing future growth opportunities. The dealings call for Lucara to get Motapa in exchange for shares which will result in Motapa shareholders owning 35% of the combined company. Each Motapa share gonna be exchanged for 0.9055 share of Lucara.
posted by Tamil Nadu ,Tamilnadu Government,Places,Wild Life,Hill Stations,Temples,Sports,Accomodation,Cusine,Fine Art @ 12:22 AM
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Thursday, March 12, 2009
Diamonds are a commodity, and a potentially valuable one at that. As such, they can be bought, sold, and traded as any other commodity. Those countries that have significant diamond deposits have the potential to use the revenue that such deposits bring to enhance the lives of their people in any number of beneficial ways. Unfortunately, diamonds can also be stolen or smuggled, with the funds arising used, not for the common good, but for the maintenance of criminal activity, such as money laundering or the purchase of arms. Thus the funds which could represent a potential windfall for diamond-rich countries have in the past all too often contributed to instability. This instability can have not only an internal impact, but can also affect regional stability and security, with knock-on effects for the international community.
The international community's response to the challenge of 'conflict diamonds' is known as the Kimberley Process Certification Scheme (KPCS) and has developed over the last six years. It formally came into force in January 2003, and now covers 99% of rough diamond producers and traders worldwide.
The KPCS incorporates two main principles. First, each participant agrees that no export from or import into its territory is allowed unless a Kimberley Process certificate issued by the exporting government, and attesting that the goods had been handled in accordance with the KPCS, accompanies the consignment of rough diamonds. Second, each participant agrees that it will not trade in rough diamonds with non-participants.
The Government Diamond Office (GDO) which is apart of Foreign and Commonwealth Office, is responsible for implementing the KP in the United Kingdom. To this end, we work closely with HM Revenue & Customs, the diamond industry, and civil society groups to ensure that the requirements of the KP are met.
posted by Tamil Nadu ,Tamilnadu Government,Places,Wild Life,Hill Stations,Temples,Sports,Accomodation,Cusine,Fine Art @ 10:33 PM
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