Tech Talk iconTech Talk

Laser Makes More Accurate Radar System

Using a laser to generate radio-frequency radar pulses, a group of researchers has demonstrated a radar system that they say can be smaller, more efficient, and more accurate than anything available today.

The work could make it easier for radar systems to use software-defined radio, which allows users to rapidly change the signal they generate using software rather than analog hardware components such as mixers, amplifiers, and the like. Dispensing with these electronic components would make radars smaller, lighter, and more energy efficient, making them attractive for use aboard airplanes and in remote locations. They could even be switched on the fly from acting as radars to working as communications devices, says Paolo Ghelfi, an optical communications researcher at the National Inter-University Consortium for Telecommunications in Pisa, Italy. Ghelfi, head of research Antonella Bogoni, and their colleagues describe their photonics-based, fully-digital radar system, PHODIR, in this week’s issue of Nature.

Read More

IBM Watson Takes on the Genetics of Brain Cancer

Twenty patients with an aggressive form of brain cancer will have a new doctor on their medical team: the learned geneticist known as IBM Watson. In a collaboration announced today between IBM and the New York Genome Center, IBM's Jeopardy-beating AI will analyze the genomes of those 20 patients in hopes of providing insights for their oncologists. 

IBM has been promoting its AI as a killer app for health care, thanks to Watson's natural language processing skills and machine learning abilities. Over the past two years Watson has been engaged in a separate project at New York's Memorial Sloan-Kettering Cancer Center, in which doctors are training the AI to understand the language of medicine. In that project, Watson is being taught to read patients' records and search the medical literature for relevant suggestions on treatment. 

This new project will show that Watson can provide deeper analysis for such point-of-care applications, said IBM Research's Raminderpal Singh after a press conference in New York today. For these 20 cancer patients, Watson won't just scan the medical literature for information. The AI will also scan the genetic data from the patients' own healthy cells and cancer cells, and will then search for information that's relevant to the genetic mutations in the tumor. "As genome sequencing becomes more commonplace—and it will—we'll need a way to go from mutation information to clinically actionable information," said Singh.   

Read More

The Earth Was Lucky to Dodge a Massive Solar Magnetic Storm in 2012

When the largest magnetic storm ever recorded struck Earth in 1859, telegraph systems failed across North America and Europe and gave electric shocks to some telegraph operators. Researchers recently analyzed a similarly huge magnetic storm that missed Earth by just nine days in 2012, which could have caused trillions of dollars worth of damages to satellites and power grids.

Read More

Dean Kamen to Tech Community: "We're Not Creating Enough Innovators"

Dean Kamen, the celebrated inventor and entrepreneur and tireless advocate for science and technology, had a clear message for his audience at the South By Southwest (SXSW) festival in Austin last week: The tech community needs to work harder to attract more young people to careers in technology and engineering. “We’re not creating enough innovators,” he said.

Read More

Scientists Must Stop Confusing Batteries and Supercapacitors, Argue Experts

What’s in a name? More than you'd care to think about when it comes to energy storage, a team of researchers from France and the United States argued last week in the journal Science. As the energy storage field has taken off in the past five to seven years, the line between batteries and supercapacitors (also called ultracapacitors) has started to blur and scientists and engineers have become less and less consistent when naming these devices, the researchers say.

Much too often, battery materials are called supercapacitors in the scientific literature, unknowingly or perhaps deliberately, says Yury Gogotsi, a materials science and engineering professor at Drexel University and one of the authors of an essay in last week's Science. “Confusion doesn’t help progress,” he says. “Attempts to sell a poor material as a good one by using wrong terminology really holds back research and leads to a waste of money and time.”

Read More

How Do You See Gravitational Waves?

On Monday, a team of astronomers announced some very big, potentially Nobel Prize-winning news: the first sighting of gravitational waves that filled the very early universe. 

The detection, which was made by the BICEP2 experiment in Antarctica, still needs to be confirmed by other experiments. But if it is, the signal could provide a window into "inflation"—a brief but explosive period when the universe is thought to have ballooned enormously in size. "This is literally a window back to almost the beginning of time itself," physicist Lawrence Krauss told Wired magazine.  

As a technology-minded physics buff, I inevitably wind up asking two very basic questions whenever a long-sought discovery takes place. First, why didn't we see this before? And, second, why are we seeing it now?

The answer to the first question is pretty much what you'd expect: the signal is quite hard to see. Like a number of ongoing experiments, BICEP2 hunted for evidence of primordial gravitational waves in the cosmic microwave background (CMB), a haze of light that was given off when the universe was just 380 000 years old. After some 13.8 billion years of cosmic expansion, the wavelength of this relic radiation has been stretched so that the photons now reaching Earth sit in the microwave band of the electromagnetic spectrum.

Read More

Bionically Enhanced Chloroplasts Boost Photosynthesis and Spawn a New Field

Consider for a moment the magical work done by chloroplasts. These are the plant organelles that absorb light from the sun, convert it into chemical energy and ultimately use it as a building block for synthesizing glucose, the primary source of fuel for both plants and animals. While their achievement has the appearance of alchemy, like every other organelle, these chloroplasts are but little machines. Now, it seems they're due for an upgrade.

In a paper published yesterday in the journal Nature Materials, chemical engineers at the Massachusetts Institute of Technology report that when injected with single-walled carbon nanotubes (SWNTs), chloroplasts can be coaxed to photosynthesize more efficiently than normal.

The first phase of photosynthesis, referred to commonly as the "light reactions," involves excitation of pigments and the subsequent transport of electrons between multiple photosystems. The researchers used this flow of electrons as a measurement for the rate of photosynthesis and found that when the nanotubes were present the flow increased by 49 percent.

Chlorophyll, the pigment normally found in chloroplasts, can only absorb a small fraction of the light entering a plant, most of which resides in the 400 to 500-nanometer and 600 to 700-nanometer range. Although the researchers cannot yet offer an explanation for why carbon nanotubes would enhance the efficiency of chloroplasts, the team theorizes that it may be due to a broadening of this range. SWNTs are known to absorb light in the ultraviolet, visible, and near-infrared spectra.

The MIT engineers write:

"Improving photosynthetic efficiency may require extending the range of solar light absorption, particularly in the near-infrared spectral range, which is able to penetrate deeper into living organisms."

They report having the most success with chloroplasts that had been removed from the plant. Under these circumstances, they were able to inject the nanotubes directly into the organelle. 

In a separate experiment, the researchers sought to find a way to deliver nanotubes into a living plant. In order to do this, they developed a new technique called lipid exchange envelope penetration. Basically, they applied the nanotubes to underside of the leaf via a watery solution which is absorbed through tiny pores called stomata. The transfer across the fatty membrane of the chloroplast was made possible by coating the carbon nanotubes in negatively charged DNA.

When they introduced machinery into a living plant in this way, the chloroplasts received slightly less of a boost, photosynthesizing only 30 percent more efficiently than normal. But this delivery technique may itself be counted as a breakthrough.  

With it, the researchers have tried packing plant cells with particles that protect it from the damaging effects of light exposure, and with another type of carbon nanotube that has been shown to be sensitive to nitric oxide. With such techniques, chemical engineers may one day develop plants that function as pollution detectors. 

Indeed the researchers are arguing that their work establishes an entire new field of research, one they're calling plant nanobionics.

Malaysia Air Flight 370 Would Not Have Disappeared if We'd Had This System

A real-time flight-data recording method could have given investigators a far better idea of what has happened to Malaysian Airlines Flight 370, says Krishma Kavi, a professor of computer science and engineering at the University of North Texas, in Denton.

Kavi described such a system in detail iIEEE Spectrum in 2010, calling it the glass box, in contrast to the black box, which records flight data and voice data. The black box can be replayed only after the fact, and then only if it can be salvaged from an airliner's wreckage; the proposed glass box would immediately transmit the data to the cloud—the network of servers that increasingly blankets the earth.

"I strongly believe that our version of the black box (glass box) would have provided information indicating that all components of the plane were operating" in the wayward MH 370,  he said in an email yesterday. "It would have provided data on speed, altitude, direction of the flight... in real time."

Read More

Soraa Aims for Better Light Quality with Gallium Nitride Tech

In the LED lighting industry, it’s an all-out race to lower costs and drive adoption. But LED company Soraa is betting that people will also purchase LEDs for the quality of light, as much as for efficiency and long life.

The Fremont, Calif.-based company said it intends to release a set of lamps later this year based on its third-generation LEDs, which use gallium nitride on a gallium nitride substrate. Soraa’s LED technology is different than most. The bulk of LEDs are made with GaN on a substrate of sapphire, while LED company Cree uses a silicon carbide substrate. A number of companies, including Bridgelux, are seeking to lower costs by manufacturing LEDs on larger silicon wafers.

Sapphire and silicon carbide substrates are less expensive and have mature production methods. By contrast, manufacturing on GaN substrates is far more challenging technically. Sorra was co-founded by LED pioneer, Professor Shuji Nakamura, in 2008 to commercialize GaN-on-GaN LEDs. The company began selling its first product, the MR16 lamp, in 2012. 

The advantage of having the same material for the active component and substrate is that there are fewer defects, so the LEDs can withstand high power, says Mike Krames, Soraa's chief technology officer. That translates into a relatively efficient conversion of current to light and good color rendering, he says.

Soraa makes LED lamps designed to replace halogen spot lights, which are often used in places where very good light quality is important, such as retail displays and museums. Light quality is measured by its color rendering index (CRI), or how accurately artificial lights display colors. Incandescent lamps, which include halogens, have a CRI of 100, and bulbs must have a CRI of 80 to meet the EnergyStar rating. Soraa’s lamps have a color rendering index (CRI) of 95.

In an effort to match the quality of halogen lights, Soraa starts with a violet LED and uses three phosphors to create a full spectrum of visible light, and thus a higher color rendering index, Krames says. Producing a wider spectrum of light requires more energy, but because it's an LED, its lights still have a big efficiency advantage over halogens with similar light quality, he says.

“Once people get more familiarity with their options, quality of light will be a bigger deal and a bigger driver of adoption than people believe,” Krames predicts.

Krames worries that consumers could be turned off by LEDs if manufacturers sacrifice light quality. Granted, Soraa’s entire business is centered on producing premium, high-CRI products so he has a clear bias. But light quality has not been the highest priority for LED manufacturers as they seek to replace other forms of lighting.

A report by the Department of Energy’s solid-state lighting program noted that LED prices have dropped dramatically and efficiency has improved over the past four years, but the quality has remained about the same. The majority of the bulbs surveyed by the DOE have a CRI between 80 and 85, which is the typical rating for compact fluorescent lamps.

Instead, LED lighting companies have focused on bringing down price—something they've been successful at. When Philips started selling a 60-watt equivalent LED bulb with omnidirectional light in 2010, it cost almost $40. Last week, Cree cut prices by 23 percent so that a 60-watt equivalent now costs under $10. It also introduced a 100-watt equivalent priced under $20.

Cree designed its bulbs with a vertical “tower” that gives off light from the center of the bulb to mimic the way an incandescent bulb glows. The CRI of its products are about 83, which is good enough for the majority of uses, says Mike Watson, the vice president of product strategy at Cree. “What we really care most about is what consumers see. Having done many demonstrations for consumers in stores, I’m stunned at the number of people who think an LED at 83 CRI is better than an incandescent at 100,” he says.  

New lighting labels require manufacturers to indicate CRI, which could draw more consumer attention to light quality. In addition, California put in place a voluntary specification for LEDs that sets a minimum of 90 CRI. The standard was put in place to avoid a flood of low-quality LEDs, which occurred when compact fluorescent bulbs were introduced, souring many consumers’ opinions on efficient lighting.

Higher quality light does mean a more expensive product, but Krames says there's potential to improve the economics of GaN-on-GaN LEDs. Soraa's third-generation LEDs improve energy efficiency by 30 percent and, since GaN-on-GaN is relatively new, there’s more room for improvement than existing technologies, Krames says.

Premium, high-CRI bulbs are now mainly used by commercial customers, but perhaps consumers will eventually buy in, too. “Once people start to get a taste for higher CRI lamps, they’re not going to want to go back,” says Krames. 

Why There's No Real Cyberwar in the Ukraine Conflict

Warnings of a cyberwar between Ukraine and Russia over the recent Crimean crisis have been greatly exaggerated. From the start, Russia seems to have relied upon traditional military force and a barrage of old-fashioned "information war" propaganda in its swift takeover of Crimea. Whatever cyber attacks that have occurred so far probably represent the work of Russian or Ukrainian "hacktivists" rather than strategic military strikes, experts say.

Read More
Advertisement

Tech Talk

IEEE Spectrum’s general technology blog, featuring news, analysis, and opinions about engineering, consumer electronics, and technology and society, from the editorial staff and freelance contributors.

Newsletter Sign Up

Sign up for the Tech Alert newsletter and receive ground-breaking technology and science news from IEEE Spectrum every Thursday.

Advertisement
Load More