The result is an efficient solar heating metamaterial that can heat up rapidly to 83 degrees C (181 degrees F) in an open environment with minimal heat loss. Proposed applications for the film include thermal energy harvesting and storage, thermoelectricity generation, and seawater desalination.
At 35 meters, the wingspan of the new BAE Systems aircraft equals that of a Boeing 737, yet the plane weighs in at just 150 kilograms, including a 15 kg payload. The unmanned plane, dubbed the PHASA-35 (Persistent High-Altitude Solar Aircraft), made its maiden voyage on 10 February at the Royal Australian Air Force Woomera Test Range in South Australia.
“It flew for just under an hour—enough time to successfully test its aerodynamics, autopilot system, and maneuverability,” says Phil Varty, business development leader of emerging products at BAE Systems. “We’d previously tested other sub-systems such as the flight control system in smaller models of the plane in the U.K. and Australia, so we’d taken much of the risk out of the craft before the test flight.”
The prototype aircraft uses gallium arsenide–based triple-junction solar cell panels manufactured by MicroLink Devices in Niles, Ill. MicroLink claims an energy conversion efficiency of 31 percent for these specialist panels.
“For test purposes, the solar panels—which are as thin as paper—covered just part of the wingspan to generate 4 kilowatts of power,” says Varty. “For the production version, we’ll use all that space to produce 12 kilowatts.”
The energy is used to drive two brushless, direct-drive electric motors modified for the aircraft, and to charge a lithium-ion battery system comprising over 400 batteries that delivers the energy needed to fly the plane at night. They are supplied by Amprius Technologies in Fremont, Calif.
Varty says that unlike the solar panels, which have been chosen for their high efficiency, the batteries—similar to the kind powering smartphones—are not massively efficient. Instead, they are a proven, reliable technology that can easily be replaced when a more efficient version becomes available.
“Although the test flight took place in Australia’s summer, the aircraft is designed for flying during the worst time of the year—the winter solstice,” says Varty. “That’s why it has the potential to stay up for a whole year in the stratosphere, around 65,000 feet [20,000 meters], where there’s little wind and no clouds or turbulence.”
He describes the unmanned control flight system as a relatively simple design similar to that used in drones and model airplanes. A controller on the ground, known as the pilot, guides the plane, though the aircraft can also run on autopilot using a preprogrammed route. Other technicians may also be involved to control specialist applications such as cameras, surveillance, or communications equipment.
The aircraft was originally developed by Prismatic Ltd., a designer and manufacturer of unmanned aerial vehicles in Southwest England that was acquired last year by BAE.
Further test flights are planned for this year and engineers from Prismatic and BAE are using the results of the trial to improve the various subsystems.
“There were no surprises found during the test flight so perhaps the biggest challenge now is educating the market that what we are offering is different,” says Varty. “Different from satellites or drones.”
Its special feature is it can sit in the stratosphere over a particular point by flying into the wind or doing maneuvers like a figure eight and using cameras or surveillance equipment mounted on gimbals to provide constant monitoring. By comparison, Varty says, even the best military drones can stay airborne for a maximum of only three days; satellites are limited by virtue of the fact that they have to maintain a speed of 7 kilometers per second or more in order to stay in orbit.
“Satellites provide merely a date-time snapshot of what is going on below,” Varty points out. “Whereas we can monitor a spot for as long as necessary to draw conclusions about what is likely to happen next: where forest fires are going to spread, for instance, or where disaster relief is most needed.”
Compared to satellites, its “lower altitude means it should realize higher resolution monitoring, low power communications, dedicated local area services, and so on. But performance, he adds, “will be strongly dependent on the equipment constraints such as mass, volume, and power budget” because the aircraft’s lightweight design limits its payload.
As for possible drawbacks, Matsunaga suspects long-duration operations—which assumes no maintenance and no failures—may be more difficult to achieve and more expensive to deal with that BAE expects. “The flights must always be controlled, and the available time for [issue-free] flights will be short. Communications with the plane’s tracking control and operation systems may also be a concern over long flights. And there’s the possibility that external disturbances may affect sensor resolution.”
BAE plans to offer several different services to customers based on the aircraft’s ability to constantly monitor a particular point or to provide it with communications via onboard transceiver equipment. “A customer could use it to monitor how crops are growing or how minute by minute, hour by hour changes to weather affect areas of interest on the ground,” says Varty. “Now we’re working out the pricing for such services. Direct sales of the aircraft are also possible.”
Commercialization will soon follow completion of the flight trials, which could mean the launch of services as early as next year.
Toshiba has come up with a new way of solving combinatorial optimization problems. A classic example of such problems is the traveling salesman dilemma, in which a salesman must find the shortest route between many cities.
Such problems are found aplenty in science, engineering, and business. For instance, how should a utility select the optimal route for electric transmission lines, considering construction costs, safety, time, and the impact on people and the environment? Even the brute force of supercomputers is impractical when new variables increase the complexity of a question exponentially.
But it turns out that many of these problems can be mapped to ground-state searches made by Ising machines. These specialized computers use mathematical models to describe the up-and-down spins of magnetic materials interacting with each other. Those spins can be used to represent a combinatorial problem. The optimal solution, then, becomes the equivalent of finding the ground state of the model.
Using radio frequencies to transmit data over existing power lines both inside and outside of homes has long promised to turn legacy cabling into a more attractive asset by delivering two essential services on a single wire. But broadband over power lines (BPL) has never achieved its potential, due in part to initial low speeds and unreliability, and concerns about radio interference and electromagnetic radiation.
One company that has continued to invest in and improve BPL since 2000 is Panasonic, a multinational electronics and appliance manufacturer with headquarters in Osaka, Japan. In March of this year, the IEEE Standards Association approved the IEEE 1901a standard for BPL that covers IoT applications, and which is based on Panasonic’s upgraded HD-PLC technology.
HD-PLC (high-definition power line communications) is backward compatible with IEEE’s 1901 standard for BPL ratified in 2010. The 1901a standard implements new functions based on Panasonic’s Wavelet orthogonal frequency-division multiplexing (OFDM) technology that is also incorporated in the 2010 standard.
The world’s first floating nuclear power plant (FNPP) docked at Pevek, Chukotka, in Russia’s remote Far East on 14 September. It completed a journey of some 9,000 kilometers from where it was constructed in a St. Petersburg shipyard. First, it was towed to the city of Murmansk, where its nuclear fuel was loaded, and from there took the North Sea Route to the other side of Russia’s Arctic coast.
The co-generation plant, named the Akademik Lomonosov, consists of a non-motorized barge, two pressurized-water KLT-40S reactors similar to those powering Russian nuclear icebreakers, and two steam turbine plants.
The FNPP can generate up to 70 megawatts (MW) of electricity and 50 gigacalories of heat an hour. That is sufficient to power the electric grids of the resource-rich region—where some 50,000 people live and work—and also deliver steam heat to the supply lines of Pevek city. The plant will manage this second feat by using steam extracted from the turbines to heat its intermediate circuit water system, which circulates between the reactor units and the coastal facilities, from 70 to 130degrees C.
Construction of the floating reactor began in 2007 and had to overcome a messy financial situation including the threat of bankruptcy in 2011. The venture is based on the small modular reactor (SMR) design: a type of nuclear fission reactor that is smaller than conventional reactors. Such reactors can be built from start to finish at a plant and then shipped—fully-assembled, tested, and ready to operate—to remote sites where normal construction would be difficult to manage.
Andrey Zolotkov, head of the Murmansk, Russia office of Bellona Foundation, an environmental organization based in Oslo, Norway, acknowledges the practicability of the SMR design. But he is one of many who questions its necessity in this particular case.
“The same plant could be built on the ground there (in Chukotka) without resorting to creating a floating structure,” says Zolotkov. “After all, the [nuclear power plant] presently in use was built on land there and has been operating for decades.”
The floating design has raised both environmental and safety concerns, given that the plant will operate in the pristine Arctic and must endure its harsh winters and choppy seas. Greenpeace has dubbed it a “floating Chernobyl,” and “a nuclear Titanic.”
Coastal structures, dams, and breakwaters have also been built to protect the vessel against tsunamis and icebergs.
The plant employs a number of active and passive safety systems, including an electrically-driven automated system and a passive system that uses gravity to insert control rods into the reactor core to ensure the reactor remains at subcritical levels in emergencies. The reactors also use low enriched uranium in a concentration below 20 percent of Uranium-235. This makes the fuel unsuitable for producing nuclear weapons.
Given such safety measures, Rosatom says on its site that a peer-reviewed probabilistic safety assessment modeling of possible damage to the FNPP finds the chances of a serious accident happening at the FNPP “are less than one hundred thousandth of a percent.”
Zolotkov, who worked in various capacities—including radiation safety officer—for 35 years in Russia’s civilian nuclear fleet, also notes that there have been no serious incidents on such ships since 1975. “In the event of an accident in the FNPP, the consequences, I believe, would be localized within its structure, so the release of radioactive substances will be minimal,” he says.
The plant’s nuclear fuel has to be replaced every three years. The unloaded fuel is held in onboard storage pools, and later in dry containers also kept on board. Every 10 to 12 years during its 40-year life cycle (possibly extendable to 50 years), the FNPP will be towed to a special facility for maintenance.
After decommissioning, the plant will be towed to a deconstruction and recycling facility. Rosatom says on its site, “No spent nuclear fuel or radioactive waste is planned to be left in the Arctic—spent fuel will be taken to the special storage facilities in mainland Russia.”
Rosatom has not disclosed the cost of the venture, calling it a pilot project. It is currently working on a next-generation version that will use two RITM-200M reactors, each rated at 50 MW. Improvement targets include a more compact design, longer periods between refueling, flexible load-following capabilities, and multipurpose uses that include water desalination and district heating.
Provided Rosatom receives sufficient orders, it says it aims to compete in price with plants based on fossil fuels and renewable energy.
The company, however, may face challenges other than marketing and operating its novel design. “These FNPPs will eventually carry spent nuclear fuel and are not yet recognized by international maritime law,” says Zolotkov. “So Rosatom may face problems obtaining permits and insurance when it comes to towing them along certain sea routes.”
Japanese scientists have developed a thermal battery that converts heat into electricity when buried in a geothermal zone
You can fry an egg on the ground in Las Vegas in August, but try that in Iceland or Alaska and you’ll just end up with the stuff on your face—unless you know how to tap into the Earth’s vast reservoirs of geothermal energy.
Researchers at the Tokyo Institute of Technology have developed a new kind of battery that can reliably generate electric power from heat in environments with temperatures ranging from 60 degreesC to 100 degreesC—which is low enough to mimic geothermal heat.
In an earlier experiment, the researchers developed sensitized thermal cells (STCs) that employed dye-sensitized solar cells to convert light into electric power. In their latest advance, team leader Sachiko Matsushita, an associate professor at Tokyo Tech, explained that they replaced the dye with a semiconductor to enable the cells to operate using heat instead of light.
SimBlock, a new blockchain simulator, lets users play around with the parameters of Bitcoin, Litecoin, and Dogecoin
Blockchain technology records information to a ledger shared between thousands of nodes. In the technology’s purest form, those nodes are not controlled by any central authority, and information cannot be changed once written to the ledger. Because of the security and autonomy this technology offers (in theory at least), blockchains now underpin many popular cryptocurrencies such as Bitcoin.
But as Kazuyuki Shudo, an associate professor at the Tokyo Institute of Technology, points out, “It has been nearly impossible to test improvements on real-world blockchain networks, because that would mean having to update the software of all the thousands of nodes on a network.”
In researching blockchains, Shudo and his colleagues searched for a simulator that would help them experiment with and improve the technology. But existing simulators were too hard to use and lacked the features the team wanted. Moreover, these simulators had apparently been created for specific research and were abandoned soon after that work was completed, because many of the tools the group found were no longer being updated.
An Australian research team is using tech to monitor global climate change’s assault on the world’s largest living organism
The stats are daunting. The Great Barrier Reef is 2,300 kilometers long, comprises 2,900 individual coral reefs, and covers an area greater than 344,000 square kilometers, making it the world’s largest living organism and a UNESCO World Heritage Site.
A team of researchers from Queensland University of Technology (QUT) in Brisbane, is monitoring the reef, located off the coast of northeastern Australia, for signs of degradation such as the bleaching caused by a variety of environmental pressures including industrial activity and global warming.
The team, led by Felipe Gonzalez, an associate professor at QUT, is collaborating with the Australian Institute of Marine Science (AIMS), an organization that has been monitoring the health of the reef for many years. AIMS employs aircraft, in-water surveys, and NASA satellite imagery to collect data on a particular reef’s condition. But these methods have drawbacks, including the relatively low resolution of satellite images and high cost of operating fixed-wing aircraft and helicopters.
So Gonzalez is using an off-the-shelf drone modified to carry both a high-resolution digital camera and a hyperspectral camera. The monitoring is conducted from a boat patrolling the waters 15 to 70 km from the coast. The drone flies 60 meters above the reef, and the hyperspectral camera captures reef data up to three meters below the water’s surface. This has greatly expanded the area of coverage and is helping to verify AIMS’s findings.
The digital camera is used to build up a conventional 3D model of an individual reef under study, explains Gonzalez. But this conventional camera is capable of capturing light only from three spectral channels: the red, green, and blue covering the 380-to-740-nanometer portion of the electromagnetic spectrum. The hyperspectral camera, by contrast, collects the reflected light of 270 spectral bands.
“Hyperspectral imaging greatly improves our ability to monitor the reef’s condition based on its spectral properties,” says Gonzalez. “That’s because each component making up a reef’s environment—water, sand, algae, etc.—has its own spectral signature, as do bleached and unbleached coral.”
But this expansion in reef coverage and richness of gathered data presented the team with a new challenge. Whereas AIMS divers can gather information on 40 distinct points on a reef in an underwater session, just one hyperspectral image presents more than 4,000 data points. Consequently, a single drone flight can amass a thousand gigabytes of raw data that has to be processed and analyzed.
In processing the data initially, the team used a PC, custom software tools, and QUT’s high-performance computer, a process that took weeks and drew heavily on the machine’s run time.
So the team applied for and received a Microsoft AI for Earth grant, which makes software tools, cloud computing services, and AI deep learning resources available to researchers working on global environmental challenges.
“Now we can use Microsoft’s AI tools in the cloud to supplement our own tools and quickly label the different spectral signatures,” says Gonzalez. “So, where processing previous drone sweeps used to take three or four weeks, depending on the data, it now takes two or three days.”
This speedup in data processing is critical. If it took a year or more before the team were able to tell AIMS that a certain part of the reef is degrading rapidly, it might be too late to save it.
“And by being informed early, the government can then take quicker action to protect an endangered area of the reef,” Gonzalez adds.
He notes that the use of hyperspectral imaging is now a growing area of remote sensing in a variety of fields, including agriculture, mineral surveying, mapping, and location of water resources.
For example, he and colleagues at QUT are also using the technology to monitor forests, wheat crops, and vineyards that can be affected by pathogens, fungi, or aphids.
Meanwhile, over the next two months, Gonzalez will continue processing the spectral data collected from the reef so far; and then in September, he will start a second round of drone flights.
“We aim to return to the four reefs AIMS has already studied to monitor any changes,” he says, “then extend the monitoring to new reefs.”
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