Thursday, August 27, 2009

Cheaper LEDs

Cheaper LEDs

Flexible arrays of bright inorganic LEDs could mean cheaper displays and lighting.

By Katherine Bourzac

THURSDAY, AUGUST 20, 2009

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A new technique makes it possible to print flexible arrays of thin inorganic light-emitting diodes for displays and lighting. The new printing process is a hybrid between the methods currently used to make inorganic and organic LEDs, and it brings some of the advantages of each, combining the flexibility, thinness and ease of manufacturing organic polymers with the brightness and long-term stability of inorganic compounds. It could be used to make high-quality flexible displays and less expensive LED lighting systems.

Stretchy screens: Arrays of tiny red inorganic LEDs can be printed on stretchable rubber substrate to conform to curves. The gold-colored wires are electrical connections and are also flexible.
Credit: Science/AAAS

Inorganic LEDs are bright and long lasting, but the expense of manufacturing them has led to them being used mainly in niche applications such as billboard-size displays for sports arenas. What's more, the manufacturing process for making inorganic LED displays is complex, because each LED must be individually cut and placed, says John Rogers, a materials science professor in the Beckman Institute at the University of Illinois at Urbana-Champaign. So display manufacturers have turned to organic materials, which can be printed and are cheaper. While LED-based lighting systems are attractive because of their low energy consumption, they remain expensive. The new printing process, developed by Rogers and described today in the journalScience, could bring down the cost of inorganic LEDs because it would require less material and simpler manufacturing techniques.

Displays based on inorganic LEDs, says Nicholas Colaneri, director of the Flexible Display Center at Arizona State University in Tempe, "are not generally economical to make." The manufacturing process involves sawing wafers of semiconducting materials such as gallium arsenide, picking and placing each piece individually using robotics, and adding electrical connections one at a time.

An Operating System for the Cloud

An Operating System for the Cloud

Google is developing a new computing platform equal to the Internet era. Should Microsoft be worried?

By G. Pascal Zachary

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From early in their company's history, Google's founders, Larry Page and Sergey Brin, wanted to develop a computer operating system and browser.

Credit: Brian Stauffer

They believed it would help make personal computing less expensive, because Google would give away the software free of charge. They wanted to shrug off 20 years of accumulated software history (what the information technology industry calls the "legacy") by building an OS and browser from scratch. Finally, they hoped the combined technology would be an alternative to Microsoft Windows and Internet Explorer, providing a new platform for developers to write Web applications and unleashing the creativity of programmers for the benefit of the masses.

But despite the sublimity of their aspirations, Eric Schmidt, Google's chief executive, said no for six years. Google's main source of revenue, which reached $5.5 billion in its most recent quarter, is advertising. How would the project they envisioned support the company's advertising business? The question wasn't whether Google could afford it. The company is wonderfully profitable and is on track to net more than $5 billion in its current fiscal year. But Schmidt, a 20-year veteran of the IT industry, wasn't keen on shouldering the considerable costs of creating and maintaining an OS and browser for no obvious return.

Finally, two years ago, Schmidt said yes to the browser. The rationale was that quicker and more frequent Web access would mean more searches, which would translate into more revenue from ads. Then, in July of this year, Schmidt announced Google's intention to launch an operating system as well. The idea is that an OS developed with the Internet in mind will also increase the volume of Web activity, and support the browser.

Google's browser and OS both bear the name Chrome. At a year old, the browser holds a mere 2 to 3 percent share of a contested global market, in which Microsoft's Internet Explorer has a majority share and Firefox comes in second. The Chrome operating system will be released next year. Today, Windows enjoys around 90 percent of the global market for operating systems, followed by Apple's Mac OS and the freeware Linux. Does Google know what it's doing?

Ritualized Suicide
Going after Microsoft's operating system used to be hopeless. When I covered the company for the Wall Street Journal in the 1990s, I chronicled one failed attempt after another by software innovators to wrest control of the field from Bill Gates. IBM failed. Sun failed. Borland. Everybody. By the end of the 1990s, the quest had become a kind of ritualized suicide for software companies. Irresistible forces seemed to compel Gates's rivals, driving them toward self-destruction.

The networking company Novell, which Schmidt once ran, could have been one of these casualties. Perhaps Schmidt's managerial experience and intellectual engagement with computer code immunized him against the OS bug. In any case, he knew that the task of dislodging Microsoft was bigger than creating a better OS. While others misguidedly focused on the many engineering shortcomings of Windows, Schmidt knew that Microsoft was the leader not for technical reasons but for business ones, such as pricing practices and synergies between its popular office applications and Windows.

Energy-Aware Internet Routing

Energy-Aware Internet Routing

Software that tracks electricity prices could slash energy costs for big online businesses.

By Will Knight

MONDAY, AUGUST 17, 2009

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An Internet-routing algorithm that tracks electricity price fluctuations could save data-hungry companies such as Google, Microsoft, and Amazon millions of dollars each year in electricity costs. A study from researchers at MIT, Carnegie Mellon University, and the networking company Akamai suggests that such Internet businesses could reduce their energy use by as much as 40 percent by rerouting data to locations where electricity prices are lowest on a particular day.

Data beast: Google maintains a huge datacenter in The Dalles, OR.
Credit: John Nelson

Modern datacenters gobble up huge amounts of electricity and usage is increasing at a rapid pace. Energy consumption has accelerated as applications move from desktop computers to the Internet and as information gets transferred from ordinary computers to distributed "cloud" computing services. For the world's biggest information-technology firms, this means spending upwards of $30 million on electricity every year, by modest estimates.

Asfandyar Qureshi, a PhD student at MIT, first outlined the idea of a smart routing algorithm that would track electricity prices to reduce costs in a paper presented in October 2008. This year, Qureshi and colleagues approached researchers at Akamai to obtain the real-world routing data needed to test the idea. Akamai's distributed servers cache information on behalf of many large Web sites across the US and abroad, and process some 275 billion requests per day; while the company does not require many large datacenters itself, its traffic data provides a way to model the demand placed on large Internet companies.

The researchers first analyzed 39 months of electricity price data collected for 29 major US cities. Energy prices fluctuate for a variety of reasons, including seasonal changes in supply, fuel price hikes, and changes in consumer demand, and the researchers saw a surprising amount of volatility, even among geographically close locations.

"The thing that surprised me most was that there was no one place that was always cheapest," says Bruce Maggs, vice president of research at Akamai, who contributed to the project while working as a professor at Carnegie Mellon and is currently a professor at Duke University. "There are large fluctuations on a short timescale."

Monday, August 3, 2009

GLOBAL WARMING


Global mean surface temperature difference from the average for 1961–1990
Mean surface temperature change for the period 1999 to 2008 relative to the average temperatures from 1940 to 1980

Global warming is the increase in the average temperature of the Earth's near-surface air and oceans since the mid-20th century and its projected continuation. Global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the last century.[1][A] TheIntergovernmental Panel on Climate Change (IPCC) concludes that increasing greenhouse gas concentrations resulting from human activity such as fossil fuel burning and deforestation caused most of the observed temperature increase since the middle of the 20th century.[1] The IPCC also concludes that variations in natural phenomena such as solar radiation and volcanoes produced most of the warming from pre-industrial times to 1950 and had a small cooling effect afterward.[2][3] These basic conclusions have beenendorsed by more than 45 scientific societies and academies of science,[B] including all of the national academies of science of themajor industrialized countries.[4] A small number of scientists dispute the consensus view.

Climate model projections summarized in the latest IPCC report indicate that the global surface temperature will probably rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during the twenty-first century.[1]The uncertainty in this estimate arises from the use of models with differing sensitivity to greenhouse gas concentrations and the use of differing estimates of future greenhouse gas emissions. Some otheruncertainties include how warming and related changes will vary from region to region around the globe. Most studies focus on the period up to the year 2100. However, warming is expected to continue beyond 2100 even if emissions stop, because of the large heat capacity of the oceans and the long lifetime ofcarbon dioxide in the atmosphere.[5][6]

An increase in global temperature will cause sea levels to rise and will change the amount and pattern ofprecipitation, probably including expansion of subtropical deserts.[7] The continuing retreat of glaciers,permafrost and sea ice is expected, with warming being strongest in the Arctic. Other likely effects include increases in the intensity of extreme weather events, species extinctions, and changes inagricultural yields.

Political and public debate continues regarding climate change, and what actions (if any) to take in response. The available options are mitigation to reduce further emissions; adaptation to reduce the damage caused by warming; and, more speculatively, geoengineering to reverse global warming. Most national governments have signed and ratified the Kyoto Protocol aimed at reducing greenhouse gasemissions.