Bangalorean shows the way to store more on less

TNN | Feb 1, 2013, 04.26 AM IST

BANGALORE: Karthik V Raman, a 27-year-old researcher with IBM, Bangalore, and alumnus of Massachusetts Institute of Technology(MIT), along with his team, has engineered templates for molecular memory devices which could store data up to 1,000 terabytes per square inch. It's a good example of the convergence of computer electronics and molecular biology as has been envisaged for some time.

Once his technology hits the market in about ten years, it could mean a dramatic shrinkage in the size of portable storage devices. Over the years, from clunky floppy disks to pen drives, there have been huge improvements in storing data - smaller devices are able to keep large amounts of data. Entire movies are now being carted around in pen drives about the size of your little finger.

Currently, the maximum storage in portable devices is 700 gigabytes per square inch. "The current technology can go up to only 1 terabyte per square inch," Karthik said, adding that it could replace the current storage technology in tablets and portable music systems. You could perhaps store your entire archive of movies, songs, photographs and videos on just one device.

The research, which was his thesis for a doctoral degree at MIT between December 2010 and June 2011, has been patented by the Boston institution. The Bangalore lad, a student of the department of material science and engineering at MIT, shares the patent with research supervisor Jagadeesh S Moodera of the department of physics and Francis Bitter of the Magnet Lab, MIT.

Karthik worked on molecular spintronics for his thesis. This is a developing area where the spin of the electrons in molecules of organic material is used to store data. The molecules largely consist of flat sheets of carbon (which are attached to zinc atoms), according to MIT News.

These molecules were developed by chemists headed by Swadhin Mandal at the Indian Institute of Science Education and Research, Kolkata. Currently, molecular storage devices work best at about -20 degree celsius.

"More research & development needs to be done before it's commercially available. We need to solve som fabrication challenges before it becomes scalable but we now know how to go about it," said Karthik.

He added, "The main problem is funding. There's very less funding in the initial stages of research in India, however ground-breaking it may be," he said.

At present, there aren't many researchers in the world working to control single molecule and molecular scale to make memory devices from them. "I'm optimistic that many researchers will start contributing to this work and in another 10 years, the device will be commercially available," he said.

The idea

A magnetic molecule (which is one-thousandth times the thickness of a human hair) on a ferromagnetic surface can now store binary information (0 and 1) allowing a thousand-fold increase in storage capacity of current hard drives. The magnetic molecule can selectively filter electrons having a spin of one kind which is needed to read information.

South Korea Makes Billion-Dollar Bet on Fusion Power

A fusion power demonstration reactor to be built in the 2030s in collaboration with the DoE's Princeton Plasma Physics Lab, represents a step toward commercial use

By Soo Bin Park and Nature magazine

fusion power, K-STAR nuclear fusion reactor, nuclear fustion

The K-STAR nuclear fusion reactor, in Daejeon, South Korea, will be succeeded by a larger, more ambitious project.Image: EPA/Corbis

From Nature magazine

South Korea has embarked on the development of a preliminary concept design for a fusion power demonstration reactor in collaboration with the US Department of Energy's Princeton Plasma Physics Laboratory (PPPL) in New Jersey.

The project is provisionally named K-DEMO (Korean Demonstration Fusion Power Plant), and its goal is to develop the design for a facility that could be completed in the 2030s in Daejeon, under the leadership of the country’s National Fusion Research Institute (NFRI).

South Korea is already developing the Korea Superconducting Tokamak Advanced Research (K-STAR) project and contributing to ITER, the €15-billion (US$20-billion) experimental reactor being built in Cadarache, France, under the auspices of an international collaboration. K-DEMO is intended to be the next step toward commercial reactors and would be the first plant to actually contribute power to an electric grid.

“It is a very smart strategy to take advantage of the experience gained in constructing ITER and to immediately proceed to construct a fusion power plant like K-DEMO,” says Stephen Dean, president of Fusion Power Associates, an advocacy group in Gaithersburg, Maryland.

K-DEMO will serve as prototype for the development of commercial fusion reactors. According to the PPPL, it will generate “some 1 billion watts of power for several weeks on end”, a much greater output than ITER's goal of producing 500 million watts for 500 seconds by the late 2020s.

Building up know-how
In early 2012, the South Korean Ministry of Education, Science and Technology announced that developing technologies to build K-DEMO would be a priority for the next 10 years, establishing the know-how to permit the construction of a commercial fusion power plant between 2022 and 2036. The government also announced that it planned to invest about 1 trillion won (US$941 million) in the project. About 300 billion won of that spending has already been funded, according to a source within the ministry. The government expects the project to employ nearly 2,400 people in the first phase, which will last throughout 2016.

Robert Goldston, who was the director of the PPPL when it helped with the initial design of K-STAR, believes that the K-DEMO project is feasible, considering South Korea's commitment to its previous project. "There was a financial crisis in Asia right in the middle of the K-STAR project, but the government and fusion scientists were steady and serious about getting the job done, despite lots of hardship," he says. "My sense is that the Korean team, at all levels, is very dedicated to a steady pace even in adversity — and there is always adversity in big projects."

Lee Gyung-Su, a research fellow at NFRI and a former chairman of the ITER Management Advisory Committee, says that Korea is desperately in need of the energy that fusion could provide. “Korea has a lack of energy resources,” he says. “The population density is high and the country consumes so much energy," Lee adds, "we have a different perspective on fusion energy compared to the United States.”

ITER has experienced repeated delays and cost increases, prompting some critics to question whether the project will ever be completed. "It is already obvious that future commercial-size machines will be too large and costly, and too expensive to operate, to generate competitive energy," says Thomas Cochran, a consultant for the Natural Resources Defense Council in Washington DC. He adds that he believes South Korea should spend its resources on technologies that have the potential to provide a nearer-term impact on carbon emissions and climate change.

Lee acknowledges the criticism, but says that most of ITER's issues were of a management, rather than a technical nature. “The schedules are now mostly fixed and sorted out,” he says. “And risks always exist when it comes to a new finding in science, and the investment on the research and development has been made based on the estimation of such risks.”

Moreover, Lee adds, “we are willing to take risks, and need to innovate to survive".

This article is reproduced with permission from the magazine Nature. The article wasfirst published on January 21, 2013.

Dung beetles follow the stars

AFP

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Dung beetles use light from the Milky Way to roll their balls of precious dung out of the way of competitors, scientists reported.

Even though they have just a tiny brain and weak eyes, the beetles use the galaxy's mass of stars, to ensure they roll the balls in a straight line and do not circle back to rivals at the dung pile.

In an unusual experiment, biologists put dung beetles under a simulated night sky provided by the local planetarium.

The Milky Way provided the beetles with a “light compass,” helping them to go in a straight line with their treasure, they found.

“The dung beetles don't care which direction they're going in — they just need to get away from the bun fight at the poo pile,” lead researcher Marcus Byrne said.

Some animals — seals, some birds and humans themselves — have been found to use the stars for navigation, but the dung beetle is the first animal that has been shown to use the galaxy itself.

Previously, the team found that dung beetles clambered on top of their dung balls, where they performed a little dance to look for the best light sources for orientation.

They seem to prefer the Sun, the Moon and galactic light over a man-made sources. A celestial body is so far away that, from the beetle's perspective, it is immobile and thus provides a fixed reference point.AFP

Baffling pulsar leaves astronomers in the dark

Scientists have found that this object, whose radio emission is known to switch on and off periodically, exhibits the same behavior, but in reverse, when observed at X-ray wavelengths.

By ESA, Noordwijk, Netherlands — Published: January 25, 2013

Artist's impression of a pulsar in radio-bright mode. // Credit: ESA/ATG medialab

New observations of a highly variable pulsar using the European Space Agency’s (ESA) XMM-Newton are perplexing astronomers. Monitoring this pulsar simultaneously in X-rays and radio waves, astronomers have revealed that this source, whose radio emission is known to switch on and off periodically, exhibits the same behavior, but in reverse, when observed at X-ray wavelengths. It is the first time that a switching X-ray emission has been detected from a pulsar, and the properties of this emission are unexpectedly puzzling. As no current model is able to explain this switching behavior, which occurs within only a few seconds, these observations have reopened the debate about the physical mechanisms powering the emission from pulsars.

Few classes of astronomical objects are as baffling as pulsars, which were discovered as flickering sources of radio waves and soon after interpreted as rapidly rotating and strongly magnetized neutron stars. Although scientists have found about 2,000 pulsars since the first was discovered in 1967, a detailed understanding of the mechanisms that power them still eludes them.

“There is a general agreement about the origin of the radio emission from pulsars: It is caused by highly energetic electrons, positrons, and ions moving along the field lines of the pulsar’s magnetic field, and we see it pulsate because the rotation and magnetic axes are misaligned,” said Wim Hermsen from the Netherlands Institute for Space Research in Utrecht. “How exactly the particles are stripped off the neutron star’s surface and accelerated to such high energy, however, is still largely unclear.”

Hermsen led a new study based on observations of the pulsar known as PSR B0943+10, which were performed simultaneously in X-rays with ESA’s XMM-Newton and in radio waves. By probing the emission from the pulsar at different wavelengths, the study had been designed to discern which of various possible physical processes take place in the vicinity of the magnetic poles of pulsars. Instead of narrowing down the possible mechanisms suggested by theory, however, the results of Hermsen’s observing campaign challenge all existing models for pulsar emission, reopening the question of how these intriguing sources are powered.

“Many pulsars have a rather erratic behavior: In the space of a few seconds, their emission becomes weaker or even disappears for a while, just to go back to the previous level after some hours,” said Hermsen. “We do not know what causes such a switch, but the fact that the pulsar keeps memory of its previous state and goes back to it suggests that it must be something fundamental.”

Recent studies indicate that the switch between what is usually referred to as “radio-bright” and “radio-quiet” states is correlated to the pulsar’s dynamics. As pulsars rotate, their spinning period slows down gradually, and in some cases, the slow-down process has been observed to accelerate and slow down again in conjunction with the pulsar switching between radio-bright and radio-quiet states. The existence of correlated variations in both the rotation and emission suggests a connection between a pulsar’s immediate vicinity and, on a grander scale, its co-rotating magnetosphere, which may extend up to about 31,100 miles (50,000 kilometers) for objects like PSR B0943+10. In order for the radio emission to vary so radically on the short time scales observed, the pulsar’s global environment must undergo a very rapid — and reversible — transformation.

“Since the switch between a pulsar’s bright and quiet states links phenomena that occur on local and global scales, a thorough understanding of this process could clarify several aspects of pulsar physics. Unfortunately, we have not yet been able to explain it,” said Hermsen.

Hermsen and his colleagues planned to search for an analogous pattern at a different wavelength — in X-rays — to investigate what causes this switching behavior. They chose as their subject PSR B0943+10, a pulsar well-known for its switching behavior at radio wavelengths and for its X-ray emission, which is brighter than might be expected for its age.

“Young pulsars shine brightly in X-rays because the surface of the neutron star is still very hot. But PSR B0943+10 is 5 million years old, which is relatively old for a pulsar. The neutron star’s surface has cooled down by then,” said Hermsen.

Artist's impression of a pulsar in X-ray-bright/radio-quiet mode. // Credit: ESA/ATG medialab

Astronomers know of only a handful of old pulsars that shine in X-rays and believe that this emission comes from the magnetic poles — the sites on the neutron star’s surface where the acceleration of charged particles is triggered. “We think that, from the polar caps, accelerated particles either move outwards to the magnetosphere, where they produce radio emission, or inwards, bombarding the polar caps and creating X-ray emitting hotspots,” said Hermsen.

There are two main models that describe these processes, depending on whether the electric and magnetic fields at play allow charged particles to escape freely from the neutron star’s surface. In both cases, it is believed that the emission of X-rays follows that of radio waves, but the emission that is observed in each scenario is characterized by different temporal and spectral characteristics. By monitoring the pulsar in X-rays and radio waves at the same time, the astronomers hoped to be able to discern between the two models.

Obtaining observing time on the requested telescopes turned out to be a rather lengthy procedure. “We needed very long observations to be sure that we would record the pulsar switching back and forth between bright and quiet states several times,” said Hermsen. “So we asked for a total of 36 hours of observation with XMM-Newton. This is quite a lot of time, and it took us five years before our proposal was accepted.”

The observations were performed in late 2011. The X-ray monitoring performed with XMM-Newton was accompanied by simultaneous observations at radio waves from the Giant Metrewave Radio Telescope (GMRT) in India and the recently inaugurated Low Frequency Array (LOFAR) in the Netherlands, which was used during its commissioning phase while testing its science operations.

“The X-ray emission of pulsar PSR B0943+10 beautifully mirrors the switches that are seen at radio wavelengths, but to our surprise, the correlation between these two emissions appears to be inverse: When the source is at its brightest in radio waves, it reaches its faintest in X-rays, and vice versa,” said Hermsen.

The XMM-Newton data also show that the source pulsates in X-rays only during the X-ray-bright phase, which corresponds to the quiet state at radio wavelengths. During this phase, the X-ray emission appears to be the sum of two components: a pulsating component consisting of thermal X-rays, which is seen to switch off during the X-ray-quiet phase, and a persistent one consisting of nonthermal X-rays. Neither of the leading models for pulsar emission predicts such behavior.

“The data collected during our monitoring campaign are truly challenging our understanding of pulsars, since no current model is able to explain them,” said Hermsen. “In the second half of 2013, we plan to repeat the same study for another pulsar, PSR B1822-09, which exhibits similar radio emission properties but is characterized by a different geometrical configuration. This will allow us to study these extreme objects under different viewing angles.”

In the meantime, these observations will keep theoretical astrophysicists busy investigating possible physical mechanisms that could cause the sudden and drastic changes to the pulsar’s entire magnetosphere and result in such a curious emission.

“The unpredictable behavior of this pulsar, revealed using the great sensitivity of the telescopes on board XMM-Newton, may require a radically new approach to study the fundamental processes that power these fascinating objects,” said Norbert Schartel from ESA.