Tuesday, November 28, 2006

Computer with Nanowires

Silicon nanowires, because of their small size and excellent electronic properties, could enable ultrasensitive handheld sensors for detecting cancer or identifying biological hazards. These nanowires could also lead to more powerful, energy-efficient computer chips. But until now, prototypes of nanowire-based circuits were made using techniques that are not suitable for batch processing.

Now, researchers at Caltech have made silicon-nanowire-based logic circuits similar to the complementary metal-oxide semiconductor (CMOS) circuits used in computer chips. To make p- and n-type transistors (the two types needed in CMOS circuits), scientists first created a checkerboard pattern of the p- and n-type silicon. They doped adjacent squares with different dopants, using photolithography-produced masks. Then, they selectively etched away silicon to form orderly arrays of nanowires using a special technique developed earlier. Finally, they connected these nanowires using e-beam lithography to form transistors and a fundamental type of logic circuit called an inverter.

Because the new method can produce both types of transistors on a single surface, it could be suitable for mass production. The new methods could finally make nano­wire circuits practical to manufacture.

Reference: Dunwei Wang, Bonnie Sheriff, and James R. Heath, “Complementary Symmetry Silicon Nanowire Logic: Power-Efficient Inverters with Gain,” Small (cover article) 2(10), 1153-1158 (2006). Link to Article.

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Tuesday, November 14, 2006

Intel's Quad Core Processor

Today morning Intel announced that it will be releasing quad-core processor products geared for servers and workstation PCs. These new processors are made up of two Xeon 5100 dual-core processors in a single unit. This release puts Intel ahead of its rival Advanced Micro Devices (AMD), which is expected to release a quad-core processor in mid-2007.

Dell, IBM and Hewlett-Packard all are launching about 200 new computer systems -- ranging from servers to workstations to gaming systems -- containing Intel's quad-core chips — Xeon 5300 and Core 2 Extreme QX6700, Intel said.

Intel said its Quad-Core 'Clovertown' Xeon 5300 and its 'Kentsfield' Core 2 Extreme Quad-Core will be up to 50% faster than the Dual-Core Xeon 5100 family Intel launched less than five months ago. The QX6700 will be the fastest processor on earth — at least until AMD releases its processor. Intel and AMD have taken different approaches to the quad-core processor, with AMD creating a 'monolithic' design in which all four processing cores sits on a single piece of silicon, as opposed to Intel's design of two dual-core processors in a single unit.

The Core 2 Extreme quad-core is priced at $999 and will appeal to gamers who want the best processing power in their rigs. The Xeon 5300 is aimed at companies who wish to run "multithreaded applications".

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Friday, November 03, 2006

"Web Science"

Berners-LeeSir Timothy Berners-Lee, the British scientist who invented the World Wide Web, wants to turn the Internet into a science: Web science. In keeping with his vision, the Massachusetts Institute of Technology and the University of Southampton on Thursday announced the launch of the Web Science Research Initiative (WSRI), a panel that will understand the scientific, technical and social challenges underlying the growth of the Internet.

The WSRI will have its headquarters at the Computer Science and Artificial Intelligence Laboratory at MIT and at the School of Electronics and Computer Science at the University of Southampton. The WSRI will have four directors: Tim Berners-Lee, director of the World Wide Web Consortium; Wendy Hall, professor of computer science at University of Southampton; Nigel Shadbolt, professor of artificial intelligence at the University of Southampton; and Daniel J. Weitzner, principal research scientist at MIT. The two collaborating universities will raise funds from the corporate world and set up a research centre that will sponsor Ph.D. students and ultimately create undergraduate curricula in Web science.

In a recent article, Berners-Lee had said that the Web has changed the ways people communicate, collaborate, and educate. But with the Net evolving rapidly, it is necessary to understand its potential impact in the future too. He said that since humans are the creators of Web pages and links between them, their interactions form emergent patterns in the Web at a macroscopic scale. These human interactions are, in turn, governed by social conventions and laws. Web science, therefore, must be inherently interdisciplinary; its goal is to both understand the growth of the Web and to create approaches that allow new powerful and more beneficial patterns to occur.

Berners-Lee said that the social aspect of the Web demands that a field separate from computer science be explored. The WSRI members say that these social scientists and life sciences gurus can help study online communities and help 'Web scientists' understand how the Web operates and how it can be more responsive to the existing relationships people actually have online. The initiative will lead to better understanding of the Internet and will help improve the way people communicate, learn and work on the Internet.

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