Graphene control cutting using an atomic force microscope based nanorobot

Tweet Scientia Sinica Physica - Graphene control cutting using an atomic force microscope based nanorobot

The electrical properties of graphene strongly rely on its size,geometry and edge structure.Therefore,the ability of fabricating graphene into desired configuration is one of the enabled techniques to manufacture graphene-based nanodevices and push it into practical applications.However,there is no effective way to achieve this goal till today. In this paper,an Atomic Force Microscopy(AFM)based mechanical cutting method is developed to meet the urgent need of graphene fabrication. Theoretical analysis between cutting force and lattice cutting angle is carried out,which reveals that the value of the cutting force is related with the graphene cutting direction.Different graphene shapes are fabricated to demonstrate the efficiency and effectiveness of the proposed method. Furthermore,after many times of cutting experiments with the rotation sample method, we proved that the cutting forces do vary with the lattice cutting direction.The experimental results keep consistent with the theoretical analysis.This discovery makes it possible to build a close-loop fabrication method with real-time force as sensor feedback.It also lays the foundation of theory and experiments on controllable graphene cutting with lattice precision.Combining parallel multi-tip technology,the proposed method makes it possible to fabricate large-scale graphene-based device at low cost and high efficiency.

Caption: This shows graphene cutting results based on a nanorobot. Credit: ©Science China Press

Eurekalert - Graphene Cutting Results Based on a Nanorobot

Under the right circumstances, solar cells from Semprius could produce power more cheaply than fossil fuels

Tweet Technology Review - this past winter, a startup called Semprius set an important record for solar energy: it showed that its solar panels can convert nearly 34 percent of the light that hits them into electricity. Semprius says its technology, once scaled up, is so efficient that in some places, it could soon make electricity cheaply enough to compete with power plants fueled by coal and natural gas.

Semprius uses gallium arsenide, which is better than silicon at turning light into electricity (the record efficiency measured in a silicon solar panel is about 23 percent). But gallium arsenide is also far more expensive, so Semprius is trying to make up for the cost in several ways.

By combining the world’s most efficient multi-junction solar cells with superior module design, Semprius holds the world record for module efficiency, reaching 33.9 percent, as confirmed by the Instituto de Energía ­Solar at the Universidad Politécnica de Madrid. Semprius modules are two-to-three times more efficient than traditional silicon and thin-film modules, delivering more than 300 watts per square meter.

Semprius website provides details

Village-scale DC solar grids provide power for lighting and cell phones

Tweet Technology Review - Nearly 400 million Indians, mostly those living in rural communities, lack access to grid power. For many of them, simply charging a cell phone requires a long trip to a town with a recharging kiosk, and their homes are dimly lit by sooty kerosene-fueled lamps.

Nikhil Jaisinghani and Brian Shaad cofounded Mera Gao Power. Taking advantage of the falling cost of solar panels and LEDs, the company aims to build and operate low-cost solar-powered microgrids that can provide clean light and charge phones. Microgrids distribute electricity in a limited area from a relatively small generation point. While alternative solutions, such as individual solar-powered lanterns, can also provide light and charge phones, the advantage of a microgrid is that the installation cost can be spread across a village. The system can also use more efficient, larger-scale generation and storage systems, lowering operational costs.

For a cost of $2,500, a hundred households, in groups of up to 15, can be wired up to two generation hubs, each consisting of a set of solar panels and a battery pack. The grid uses 24-volt DC power throughout, which permits the use of aluminum wiring rather than the more expensive copper wiring required for higher-voltage AC distribution systems. The village is carefully mapped before installation to ensure the most efficient arrangement of distribution line.

Each household gets 0.2 amps for seven hours a night—enough to power two LED lights and a mobile-phone charging point—for a prepaid monthly fee of 100 rupees (a little less than US$2, current exchange 55 rupee to 1 US dollar); kerosene and phone charging generally cost 100 to 150 rupees a month.

A typical installation uses two banks of solar panels, located on different rooftops. Credit: Anna Da Costa

This business model and technology will enable everyone in the world to have basic electricity and along with low cost $10-20 smartphones, everyone will have a computer and mobile communication.

Mera Gao Power website

Quality, dependable light transforms lives; children are able to study at night, adults are able to earn additional income, and indoor air quality is improved. Our services benefit women who traditionally spend more time working indoors and children who accidentally drink kerosene and inhale its fumes. With a commercial model, MGP expects to scale up its services to reach 1,000,000 people by 2017.

Tesla Motors on track for profitability in 2013

Tweet Tesla Motors is on track for profitability in 2013. Tesla is using an aging factory and second-hand equipment. With the going price to build a North American auto plant averaging $1 billion, Tesla may have spent less than a third that much to buy, renovate and equip its factory. It paid $42 million for the plant in 2010, spent $17 million for some of its presses and machinery, and got other used equipment at a “fraction” of the original cost from parts suppliers including Tower Automotive Inc., said Passin, 51. Tesla is on schedule to build about 5,000 cars this year in Fremont and 20,000 in 2013, Passin said. Output may grow to about 40,000 vehicles annually after that with the addition of the Model X electric sport-utility vehicle and other projects.

Google's Larry Page talks about Looking Beyond Today

Tweet Larry’s 20-minute talk presents some insights into the Google worldview, both in terms of where the company invests its energy and how it is shaping the future. But his real message extended beyond Google’s accomplishments and aimed squarely at encouraging people to make bold dreams that take advantage of the amazing opportunities modern technology provides and is capable of. The moments in his talk when his excitement came through earmarked an insider’s vision of a rapidly approaching reality that will be amazing.

Larry Page - With more ambitious goals we can double the rate of human progress. The world has enough resources.

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How strong is China’s economy?

Tweet Economist Magazine - Despite a recent slowdown, the world’s second-biggest economy is more resilient than its critics think.

Rapid development can look messy close up, as our special report this week explains; and there is much that is going wrong with China’s economy. It is surprisingly inefficient, and it is not as fair as it should be. But outsiders’ principal concern—that its growth will collapse if it suffers a serious blow, such as the collapse of the euro—is not justified. For the moment, it is likely to prove more resilient than its detractors fear. Its difficulties, and they are considerable, will emerge later on.

* Money has been borrowed from China's own people and not foreigners (far less risk of capital flight)
* China's banks are highly liquid
* China's government has the financial resources to fix any insolvency that develops

RNA breakthrough transforms idea of gene control

Tweet New Scientist - It has been long known that DNA can be altered "epigenetically" – where changes occur without altering the sequence of DNA but leave chemical marks on genes that dictate how active they are by adding chemical methyl groups that silence genes, for example. Numerous environmental factors, such as stress and smoking, have been shown to influence these epigenetic marks.

Now, researchers have discovered that messenger RNA, the mirror-image copy of DNA from which all proteins are manufactured, can be methylated too.

Jaffrey's team found that around a fifth of the RNA produced in cells from rat brains and human kidneys contained methylated versions of adenosine, one of the four building blocks of our genetic code. "It was exciting to find that 20 per cent had methyl groups, so it must be a pretty fundamental regulatory mechanism," says Jaffrey.

Separate analyses of assorted rat tissues demonstrated that the methylated RNA was concentrated in the brain, liver and kidneys. Also, samples from rat embryos showed that concentrations rose 70-fold in the brain as it reached the final stages of growth, therefore they are likely to play a fundamental role in development.

The team also discovered that the methyl groups are stripped off the RNA by an enzyme linked with obesity. The enzyme is made by a gene called FTO, one variant of which raises the risk of obesity by 70 per cent. People with an overactive copy of the gene are most at risk, suggesting that stripping the methyl groups from RNA might somehow alter our metabolism.

The researchers found that methylated adenosine tended to cluster close to the point on the RNA strand where protein manufacture reaches completion, and on regions where other proteins bind to the strand to alter or halt production. The suggestion is that methylation may therefore dictate how much protein gets made, and when. "It's not changing what would be made, but it might govern how much and when it's made," says Jaffrey. This, he says, could in turn have a big impact on a multitude of physiological processes and disease.

Cell Journal - Comprehensive Analysis of mRNA Methylation Reveals Enrichment in 3′ UTRs and near Stop Codons

Technical Highlights
* m6A is a widespread RNA modification in many tissues with high levels in the brain
* MeRIP-Seq identifies m6A in 7,913 genes encoding both coding and noncoding RNAs
* m6A is enriched near stop codons and within 3′ UTRs in both mouse and human mRNAs
* The transcriptome-wide landscape of m6A provides important insights into m6A function