Table of contents:
- New solar cell breaks efficiency record
- New 3D imaging system can capture single photons
- Nanosatellite "Swan" will be sent into space on a solar sail
- Scientists have patented the system of power supply of the Earth from space
- The recognition system will allow drones to fly 10 times faster and not crash
- Singapore scientists have learned how to make excellent airgel from old tires
- An unmanned aerotaxi is being developed in the Russian Federation
- Toyota and Lexus develop technology to make carjacking meaningless
- Russian electric motor on superconductors will be tested in flight
Fresh news of science and technology. We publish the latest discoveries of scientists, technical reviews, the latest news from the Internet and hi-tech.
New solar cell breaks efficiency record
Stacking perovskite solar cells on top of silicon solar cells is one way to increase the amount of sunlight used.
The use of solar photovoltaic cells as a renewable energy source is on the rise as the technology becomes more efficient and less expensive.
Stacking perovskite solar cells on top of silicon cells is one way to increase the amount of sunlight used, and now researchers at the Australian National University have broken an efficiency record for these tandem solar cells.
The researchers say their new solar cells based on perovskite and silicon have achieved 27.7% efficiency in converting sunlight into energy. This is more than double what technology could have produced just five years ago (13.7 percent), and this is a decent step up from the reports two years ago - 25.2 percent.
Interestingly, the technology already outperforms most commercially available solar panels, which hover around the 20 percent efficiency mark. They are based solely on silicon and are expected to reach their maximum limit in the next few years.
Both silicon and perovskite are good at converting sunlight into energy, but together they work even better. This is because the two materials absorb light of different wavelengths - silicon collects mainly red and infrared light, while perovskite specializes in green and blue.
To make the most of this, the researchers stack translucent perovskite cells on top of silicon ones. Perovskite picks up what it needs, while other wavelengths are filtered to silicon.
Scientists are now working to improve efficiency even more, with the technology commercializing rapidly approaching. Efficiency must be around 30 percent before it is viable for mass production, according to the researchers, and this is expected to happen by 2023.
New 3D imaging system can capture single photons
New technology is the first real demonstration of single-photon noise reduction
Researchers at Stevens Institute of Technology have created a 3D imaging system that uses the quantum properties of light to create images 40,000 times sharper than current technology. The discovery paves the way for effective use of the LIDAR system in self-driving cars and satellite mapping systems, communications in space, etc.
The work addresses a long-standing problem with LIDAR, which fires lasers at distant targets and then detects reflected light. While the light detectors used in these systems are sensitive enough to create detailed images of a few photons - tiny particles of light, it is difficult to distinguish reflected fragments of laser light from brighter background light such as sunlight.
“The more sensitive our sensors become, the more sensitive they become to background noise,” the scientists say. "This is the problem we are currently trying to solve." The new technology is the first real demonstration of single-photon noise suppression using a technique called Quantum Parametric Sorting Mode or QPMS, which was first proposed in 2017.
Unlike most noise filtering tools that rely on software post-processing to clean up noisy images, QPMS validates quantum light signatures using exotic nonlinear optics to create exponentially cleaner images at the sensor level.
Finding a specific photon carrying information amid background noise is like trying to snatch one snowflake out of a blizzard - but that's exactly what the researchers succeeded in doing. They describe a method of imprinting certain quantum properties into an outgoing pulse of laser light and then filtering the incoming light so that the sensor only detects photons with matching quantum properties.
The result: an imaging system that is incredibly sensitive to photons returning from its target, but which ignores virtually all unwanted noisy photons. This approach produces crisp 3D images, even when each photon carrying the signal is drowned out by many more noisy photons.
“By clearing the initial photon detection, we push the boundaries of accurate 3D imaging in 'noisy' environments,” said Patrick Rain, lead author of the study. "We have shown that we can reduce the amount of noise by about 40,000 times what the most advanced imaging technology can provide."
In practical terms, QPMS noise reduction can enable LIDAR to be used to create accurate, detailed 3-D images at distances of up to 30 kilometers. QPMS can also be used for deep space communications, where harsh glare from the sun usually drowns out distant laser pulses. Perhaps most excitingly, this technology can also give researchers a clearer view of the most sensitive parts of the human body.
By providing near-silent single-photon imaging, the system will help researchers create clear, highly detailed images of the human retina using nearly invisible, faint laser beams that will not damage the sensitive tissues of the eye.
Nanosatellite "Swan" will be sent into space on a solar sail
The Russian nanosatellite "Lebed" may become the first spacecraft to leave Earth's orbit using a solar sail. A flight model of the satellite can be presented in three years, after which a test flight will follow.
The technique is planned to be used for research missions, which will become cheaper due to the abandonment of the use of heavy propulsion engines - this will reduce the total weight of the domestic probe. The main difference between the Lebed and foreign designs is the unique rotor design of the two-bladed sail, which makes it possible to increase its area tenfold. As the senior lecturer of the Moscow State Technical University named. Bauman Alexander Popov, a two-bladed rotary sail, patented by the university, will be installed on the Swan, which does not require a frame to deploy. “Thanks to this, we expect to increase its area tenfold with the same weight of the structure,” the scientist noted.
According to Popov, the new device will be delivered by a launch vehicle into an orbit with an altitude of 1,000 km. After that, it will begin a controlled rotation, initiated by shunting electrothermal motors - resistojets (they will receive the necessary energy from solar panels). At the same time, due to centrifugal force, two sails with a one-sided reflective coating will be launched from special cylinders on both sides of the satellite. Their total length will be about 320 m.
Scientists have patented the system of power supply of the Earth from space
The Moscow Radio Engineering Institute of the Russian Academy of Sciences received a patent for a system for transmitting energy from an orbiting solar power plant to Earth, according to the data on the website of the Federal Service for Intellectual Property.
According to the document, scientists propose to deploy a space solar power plant at an altitude of 300 to 1000 kilometers and, when flying over a ground receiving point, transmit the energy accumulated in the power plant's batteries using microwaves.
At the same time, a similar American patent of 1971 is indicated in the Russian patent, in which the idea of creating a solar space power plant was first put forward. Then the power plant was proposed to be placed in a geostationary orbit with an altitude of 36 thousand kilometers, which would allow it to be all the time practically above the same section of the Earth's surface and thereby ensure a constant transfer of energy to the Earth. However, in this case, the receiving station must be located at the equator. The Russian proposal makes it possible to transfer energy to other regions of the Earth.
In 2018, the first deputy general director of the Shvabe holding, Sergei Popov, in an interview with RIA Novosti, said that Russian scientists are developing an orbital laser with a repeater mirror, which will be able to transmit solar energy to those parts of the Earth where it is impossible or extremely difficult to build power plants, including number to the Arctic.
The recognition system will allow drones to fly 10 times faster and not crash
Engineers from the University of Zurich (Switzerland) have presented a fundamentally new collision avoidance system for drones - there is nothing faster and more accurate in the world yet. They proceeded from the fact that reaction rates of 20-40 milliseconds, as in many commercial unmanned systems, are not enough to organize the safe movement of high-speed flying drones. To demonstrate the capabilities of their brainchild, the Swiss used the bouncer game, teaching drones to masterly dodge balls flying at them.
The problem with drones' reaction time to obstacles has two roots. First, the high speed of movement of flying vehicles in comparison with ground ones. Secondly, weak computing power, due to which on-board systems do not have time to analyze the situation and recognize the interference. As a solution, the engineers replaced the sensors with "event cameras", increasing the reaction speed to 3.5 milliseconds.
The event camera reacts only to changes in the brightness of individual pixels in the frame and ignores others, so it needs to process very little information in order to detect a moving object against a static or sedentary background. Hence the high reaction speed, but in the course of practical experiments it turned out that neither the existing drones nor the cameras themselves are suitable for this purpose. The merit of the Swiss engineers is that they remade both the cameras and the platform of the quadcopters, plus they developed the necessary algorithms, in fact, creating a new system.
When playing bouncer, a drone with such a system in 90% of cases manages to evade a ball that is thrown at it at a speed of 10 m / s, from a distance of only 3 m.And this is in the presence of only one camera, if the size of the interference is known in advance - a the presence of two cameras allows him to accurately calculate all the parameters of the interference and make the right decision. Now engineers are working on testing the system in motion, when flying on difficult routes. According to their calculations, as a result, UAVs will be able to fly ten times faster than now, without the risk of collision.
Singapore scientists have learned how to make excellent airgel from old tires
Scientists at the National University of Singapore were extremely frustrated by the fact that only 40% of used tires go to recycling, so they set out to find an alternative solution to this problem. There was no clear plan, only an idea - to isolate rubber from the tire material and give it a new shape. For example, turn it into a porous airgel base - a cellular structure in which the cells are filled with gas.
During the experiments, the scientists soaked the thin fragments of tires in a mixture of "environmentally friendly" solvents and water to clean the rubber from impurities. Then the solution was digested until a uniform mass was formed, cooled to -50 ° C and lyophilized in a vacuum chamber for 12 hours. The output was a dense and lightweight airgel.
Unlike other types of aerogels, the rubber-based version turned out to be many times stronger. And after coating with methoxytrimethylsilane, it also became water-resistant, which immediately determined its promising field of application - as a sorbent for oil spill response. Yesterday's trash will help get rid of another type of waste and pollution.
But most of all, Singaporean scientists are pleased with the economic side of the invention. Creation of a sheet of rubber airgel with an area of 1 sq. M. and 1 cm thick takes 12-13 hours and costs $ 7. The process can be easily scaled up and turned into a commercially attractive business. Especially, given the enormous reserves and the cheapness of the source material.
An unmanned aerotaxi is being developed in the Russian Federation
An unmanned air taxi is being created in Russia, which will be able to transport passengers over a distance of 500 km at a cruising speed of 500 km / h. The first experimental model is planned to be created by 2025, it will be used for vertical take-off and landing.
It is expected that further a flight model will be produced, the carrying capacity of which will be 500 kg (four passengers), the newspaper Izvestia writes.
Such an air taxi is primarily designed for use in cities with a population of over one million and in the country's largest regions. The use of the vehicle will become relevant due to the lack of runways in Russia, the developers from the National Technology Initiative (NTI) explained.
“The high speed of the vehicle will be ensured by a gas turbine unit installed on board and connected to an electric generator. It feeds six stationary engines through a battery of supercapacitors,”said Pavel Bulat, deputy co-director of the Aeronet working group at NTI. According to him, the engines will rotate lifting and sustaining fans, which will be completely retracted into the fuselage, which acts as a wing. The control is planned to be carried out by jet rudders and by changing the thrust vector. The power electronics for the car will be made of silicon carbide instead of traditional silicon.
The body material will also be innovative. The designers are going to use the latest aluminum and scandium alloy. It was developed at the All-Russian Institute of Aviation Materials. This will create a lightweight all-metal welded fuselage.
Toyota and Lexus develop technology to make carjacking meaningless
Car theft is one of the biggest hassles that car owners face. Even alarm systems do not always cope with their task, but manufacturers already have a more advanced solution. From 2020, the entire range of Toyota and Lexus brands in Russia will be protected by the unique anti-theft identifier T-Mark / L-Mark.
The identifier is a marking of a car with microdots from a film with a diameter of 1 mm, on which a unique PIN-code is applied, associated with the VIN-number of a particular car. In total, up to 10,000 such points are applied to various body elements and assemblies. You can check their compliance with the "attached" vehicle on the sites toyota.ru and lexus.ru.
The use of markings allows law enforcement agencies and buyers of used cars to verify the "passport" data of the car with the actual date of its manufacture, equipment, make and engine number and other characteristics.The manufacturer positions identifiers as a solution that significantly reduces the interest of hijackers in Toyota and Lexus cars and makes it possible to exclude the possibility of resale of vehicles by them on the secondary market.
The first car to receive the L-Mark on the domestic market was the Lexus ES - according to the manufacturer, to date there have been no cases of theft of this sedan equipped with anti-theft markings. In addition, the owners of marked cars have discounts of up to 15% on the CASCO policy on the risk of theft. It is expected that the process of equipping the range of Toyota and Lexus brands in Russia with the T-Mark / L-Mark will be completed during 2020.
Russian electric motor on superconductors will be tested in flight
Specialists from TsIAM named after PI Baranov began preparations for testing the first hybrid power plant in Russia with an electric motor. RIA Novosti reported about it the day before, referring to the press service of the scientific testing center.
In the middle of this month, representatives of the institute visited FSUE SibNIA im. SA Chaplygin ", where they examined the flying laboratory at the Yak-40 base, where it is planned to test a promising unit in the future. Flight tests are expected to take place in 2 years. It is planned to install the latest high-temperature electric motor on superconductors and a cooling system in the nose of the aircraft, created by ZAO Superox by order of the FPI. Recall that this unit is a unique domestic development, which is able to provide a tangible advantage in power density and efficiency of the components of a hybrid installation, in comparison with traditional electrical equipment.
In turn, instead of one of the three motors in the "tail" of the flying laboratory, a turboshaft gas turbine unit with an electric generator, developed by the USATU, will be installed. Control system units and batteries will be placed in the Yak-40 cabin. Test engineers will also be there during the flight. The main goal of the upcoming tests is to create a demonstrator of a hybrid power plant, which in the future can be installed on promising interregional Russian aircraft.