UNU-MERIT: I&T Weekly

	Search \| Sitemap \| Intranet \| PhD Intranet

Subscribe to I&T Weekly A free e-zine about Innovation & Technology developments

text html Please type the above code:
	RSS feed

Previous Issues I&T Weekly

>> back to archive

Previous issues of I&T Weekly:

2013: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16]

2012: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37]

2011: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44]

2010: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42]

2009: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42]

2008: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41]

2007: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40]

2006: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44]

2005: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40]

2004: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43]

2003: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] [45] [46] [47]

2002: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] [45] [46] [47]

2001: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19]

Image: NanoAll

Issue no. 13, 2012 Published: Apr 27, 2012
MIT researchers find a way to make glass that's anti-fogging
Graphene emits infrared light
Clean up the cloud: making data storage greener
Tech billionaires bankroll gold rush to mine asteroids
Liquid solar cells can be painted onto windows
AI graders get top marks for scoring essay questions
Rich suffer as well as the poor in unequal society

MIT researchers find a way to make glass that's anti-fogging
One of the most instantly recognizable features of glass is the way it reflects light. But a new way of creating surface textures on glass, developed by researchers at MIT, virtually eliminates reflections, producing glass that is almost unrecognizable because of its absence of glare - and whose surface causes water droplets to bounce right off, like tiny rubber balls. The new 'multifunctional' glass, based on surface nanotextures that produce an array of conical features, is self-cleaning and resists fogging and glare, the researchers say. Ultimately, they hope it can be made using an inexpensive manufacturing process that could be applied to optical devices, the screens of smartphones and televisions, solar panels, car windshields and even windows in buildings. The surface pattern - consisting of an array of nanoscale cones that are five times as tall as their base width of 200nm - is based on a new fabrication approach the MIT team developed using coating and etching techniques adapted from the semiconductor industry. Fabrication begins by coating a glass surface with several thin layers, including a photoresist layer, which is then illuminated with a grid pattern and etched away; successive etchings produce the conical shapes. Since it is the shape of the nanotextured surface - rather than any particular method of achieving that shape - that provides the unique characteristics, the team say that in the future glass or transparent polymer films might be manufactured with such surface features simply by passing them through a pair of textured rollers while still partially molten; such a process would add minimally to the cost of manufacture.
MIT / ACS Nano Apr 26, 2012	back to top

Graphene emits infrared light
Physicists at Ames Laboratory and Iowa State University have discovered another useful property of graphene - it can function much like a laser when excited with very short light pulses. The team has shown that the material has two technologically important properties - population inversion of electrons and optical gain. The findings suggest that graphene could be used to make a variety of optoelectronics devices, including broadband optical amplifiers, high-speed modulators, and absorbers for telecommunications and ultrafast lasers. In their experiments, the team excited high-quality, epitaxially grown graphene monolayers with pump laser pulses just 35 fs long and photon energy of around 1.55 eV. They then measured how much light was reflected by the samples. Because graphene is just one atom thick and has a zero-energy electronic bandgap, this measurement provides information on the amount of light absorbed by the material. This in turn depends on the optical conductivity of graphene. The researchers found that the optical conductivity changes from being positive to negative as the intensity of the pump pulses increases. The intense external pump laser pulses excite electrons in graphene so that more of these charge carriers exist in the upper 'Dirac cone' - the conduction band of the material - than in the lower cone. Once such a population inversion has occurred, a probe photon then stimulates these excited states to emit infrared light in a coherent cascade. This optical gain could be observed over a wide range of energies - up to hundreds of millielectronvolts below the pump photon energy. Such a broad optical gain might be unique to graphene and related to the fact that photoexcited electrons in the material scatter extremely fast among themselves. What is more, an ultrashort pulse just 35 fs long is sufficient to produce this broadband gain - something that has never been seen before in any material.
Belle Dumé is a contributing editor to nanotechweb.org Apr 25, 2012	back to top

Clean up the cloud: making data storage greener
Cloud services depend on energy-hungry data centres to store information remotely. Now Greenpeace has produced an environmental report card for these data centres that gives a thumbs-up to Google and Facebook, but wags a finger at Apple, Amazon and Microsoft. To work out who has the cleanest cloud, Greenpeace looked at the capacity of existing and planned data centres and the sources of electricity used by each, based on the mix in the local grid and declared agreements to purchase from renewable sources - defined as wind, solar and existing hydropower. This indicated that data centres run by Google and Facebook draw on renewables for 39.4% and 36.4% of their power respectively, compared to just 13.9% and 13.5% for those operated by Microsoft and Amazon. Apple, with 55.1% of its iCloud powered by coal and just 15.3% drawing on renewables, also scored poorly. Our enthusiasm for cloud services means that more and bigger data centres are on the way. To lessen the impact of this growth, companies can reduce the carbon intensity of data storage. Facebook says that it has increased the energy efficiency of its data centres by 38% by redesigning the hardware - from the servers themselves, to buildings that use evaporative cooling rather than energy-hungry air conditioners. The company's blueprints are open-source so that others can use and improve on the technology.
New Scientist Apr 26, 2012	back to top

Tech billionaires bankroll gold rush to mine asteroids
Google executives Larry Page and Eric Schmidt and filmmaker James Cameron are among those bankrolling a venture to survey and extract precious metals and rare minerals from asteroids that orbit near Earth. Planetary Resources, based in Washington, initially will focus on developing and selling extremely low-cost robotic spacecraft for surveying missions. A demonstration mission in orbit around Earth is expected to be launched within two years. Planetary Resources' first customers are likely to be science agencies, such as NASA, as well as private research institutes. Within five to 10 years, however, the company expects to progress from selling observation platforms in orbit around Earth to prospecting services. It plans to tap some of the thousands of asteroids that pass relatively close to Earth and extract their raw materials. In addition to mining for platinum and other precious metals, the company plans to tap asteroids' water to supply orbiting fuel depots, which could be used by NASA and others for robotic and human space missions. The company's first step is to develop technologies to cut the cost of deep-space robotic probes to one-tenth to one-hundredth the cost of current space missions, which run hundreds of millions of dollars, Diamandis said. Among the targeted technologies is optical laser communications, which would eliminate the need for large radio antennas aboard spacecraft.
Reuters Apr 24, 2012	back to top

Liquid solar cells can be painted onto windows
Scientists at the University of Southern California have taken a big step towards the creation of solar cells in the form of a liquid ink that can be painted or printed onto clear surfaces. Liquid nanocrystal solar cells are cheaper to fabricate than current single-crystal silicon wafer solar cells - but aren't nearly as efficient at converting sunlight to electricity. Previous efforts have involved attaching organic ligand molecules to the nanocrystals to keep them stable and to prevent them from sticking together. All well and good - except that these molecules also insulate the crystals, making the cells terrible at conducting electricity. Now, though, the USC team has discovered a synthetic ligand that not only works well at stabilizing nanocrystals, but actually builds tiny bridges connecting the nanocrystals to help transmit current. Because the process used is relatively low-temperature, the solar cells can be printed onto plastic instead of glass, resulting in a flexible solar panel that can be shaped to fit anywhere. So far, the team's worked with nanocrystals made of the semiconductor cadmium selenide; the next move is to look at using materials other than cadmium, which is restricted in commercial applications because it's so toxic.
TG Daily Apr 26, 2012	back to top

AI graders get top marks for scoring essay questions
Grading software is used by some universities and US states to mark exams. But manufacturers' claims that the systems can match human raters have never been comprehensively assessed until now, says Jaison Morgan of The Common Pool, a consultancy based Santa Monica, California. To compare human and machine graders, Morgan and Mark Shermis of the University of Akron, Ohio, obtained over 16,000 essays from six state education departments. The essays covered a range of topics and had already been marked by at least one trained human grader. Grading software from nine manufacturers, which together cover 97% of the US market, was used in the test. To calibrate the systems, each looked for correlations between factors associated with good essays, such as strong vocabulary and good grammar, and the human-assigned score. After training, the software marked another set of essays without access to the human-given grades. The essay marks handed out by the machines were statistically identical to those from the human graders, says Morgan. It is an important finding, says Morgan, because teachers often do not assign essays because they do not have the time to mark them. He says it should encourage educators to use automated systems more widely.
New Scientist Apr 25, 2012	back to top

Rich suffer as well as the poor in unequal society
The rich just keep on getting richer. In most developed nations inequality has been growing for decades; last year the OECD reported that its 34 member countries were more unequal than at any time in the past 30 years. As the gulf between rich and poor rises up the political agenda so it has become an object of scientific study. The findings are not encouraging for anyone. There is already ample evidence that people at the bottom suffer a range of health problems. More controversially, unequal societies appear to have higher levels of social ills, from teenage pregnancy to violence and obesity, that affect quality of life across the board. Now there is another reason to decry growing inequality. Greater wealth correlates with selfishness and lack of empathy, which might help explain why the divide persists and the rich seem so reluctant to close it. Apologists for inequality argue that it is harmless, or even a powerful motivator. The evidence suggests otherwise. A huge gap between have and have-nots is bad both for individuals and for society. It is in everybody's interests that we narrow it.
New Scientist Apr 26, 2012	back to top