Scientists have created a radically new type of graphene speakers

Practically all the existing dynamics work on the same principle: the electric signal generates oscillations of the coil in the field of a permanent magnet, it drives the diffuser, and this, in turn, creates air vibrations and sound waves of the required frequency. But in the future, everything can change, because scientists from the British University of Exeter have created a fundamentally new type of dynamics from graphene, which does not need any mechanical vibration.

The principle of the new dynamics is based on a change in the temperature of graphene, the changes of which lead to the appearance of sound. Previously, graphene has already been used to create speakers, but in the past it was made from diffusers, which led to an increase in the efficiency of the device. From the new dynamics, all the moving parts disappeared, which allowed to reduce its size and increase its effectiveness. The speaker is made in the form factor of a microprocessor the size of a thumbnail. Inside the processor case, in addition to the speaker itself, the amplifier and even the graphic equalizer are hidden.

The thermoacoustic principle of operation allows you to convert the temperature into sound or vice versa – to convert sound vibrations into heat. This effect was first described at the end of the XIX century by the scientist Lord Rayleigh. In the middle of the twentieth century, interest in the interrelation between sound and heat greatly increased, since it was necessary to study the instability in combustion chambers with huge temperature differences. To date, there are thermoacoustic engines and even thermoacoustic refrigerators. But thermoacoustic speakers, and even from graphene, so far no one has created.

Graphene is an excellent conductor, therefore, by passing electrical impulses through it, you can quickly heat up and cool it. The grafen membrane expands and contracts, which affects the ambient air and generates sound waves. How good is the sound obtained in this way? The team of researchers claims that the graphene thermoacoustic speaker allows to get a “rich sound palette”, depending on how and where it is supplied with electricity. Heating and cooling cycles allow you to create multiple audio frequencies at the same time, while mixing them together, amplifying and tuning their sound. Scientists even managed to obtain ultrasound.

The results of research by British scientists were published in the journalScientific Reports.

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Scientists have received an “impossible” form of ice, which can exist only on Uranus

A group of scientists from the Lawrence Livermore National Laboratory received a unique form of ice, called superionic ice. The main feature of this ice is that it consists of a solid crystal lattice of oxygen atoms, around which the protons rotate. The most interesting is that the appearance of such a form of matter was predicted more than 30 years ago, and according to experts, this kind of ice can not exist on our planet, but it consists of the nuclei of ice planets like Uranus.

As is known, ice consists of water, and water is an oxygen molecule connected to two molecules of hydrogen. When water freezes, its molecules can form crystal structures of arbitrary shape. The crystal lattice of “ordinary” ice consists of hexagons, but there are other forms of ice, for example, cubic ice, the lattice of which has, as it is easy to guess, the shape of the cube. But they are formed only under certain conditions, and it will not work to get them “in their own refrigerator.” To obtain the same superionic ice, the scientists squeezed water molecules with the pressure created by two diamond platforms. This structure is called ice-VII.

Crystal structure of ice-VII

After compression of water molecules, scientists created a shock wave through the crystal structure with the help of a powerful laser. Further, by increasing the strength of the shock waves, cavities were created inside the molecule between the diamond platforms. After receiving a new form of ice, scientists have studied some of its properties.

The process of formation of ice-VII by means of a laser

It turned out that the crystal lattice could retain its structure even in the temperature range from 2000 to 5000 Kelvin. Moreover, such ice could conduct an electric current. Thus, it was possible to prove that scientists succeeded in obtaining one of the forms of superionic ice, in which the crystal lattice consists of oxygen atoms, within which the nuclei of hydrogen atoms can move freely. According to Jonathan Fortney, one of the authors of the work,

“This form of ice can maintain stability under extreme conditions that occur only in the central parts of the planetary nuclei, such as Neptune or Uranus. Of course, in addition to the ice there is a fairly large number of other substances, for example, ammonia and methane. Over time, we will try to find out whether there can be a stable superionic ice in the presence of these substances. “

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Scientists have discovered regeneration genes

As you know, there are beings on our planet who have an incredible ability to regenerate, allowing to grow lost limbs and restore organs. And many scientists have long argued that virtually any organism has the same capabilities – you just need to “include” the right genes. And recently, German scientists from the Max Planck Institute discovered such genes.

In the course of their research, the university staff examined the amphibian amphibian amphibian larvae mexicanum. The fact is that in just a few weeks she can completely restore her lost limbs. Together with bone, cartilaginous tissue, muscles, nerves and blood vessels. Moreover, this amphibian can easily cope with fractures of the spine, which for most mammals turn out to be deadly.

In the process of studying the ambystoma mexicanum larvae, the experts sequenced their genome and determined in it the key genes responsible for the regeneration of the limbs. But this process took quite a long time. The fact is that the investigated genome consists of 32 billion base pairs of DNA (which is approximately 10 times more than a human). To decipher the entire genome, scientists needed 72 million reads of DNA sections, which was helped by the analytical platform PacBio, which allows you to sequester several hundred thousand fragments per reading. In the course of further analysis of the genome, the researchers found several unique genes that are expressed in the regeneration process. It is worth noting that at first it was thought that the main one is the PAX3 gene, as well as the other representatives of the species, but it turned out that PAX3 is absent from the ambystoma mexicanum,

Of course, there is no question of “transplanting” new genes to a person, and this process requires further study. But now you can use unique properties to create drugs for wound healing and in new methods of repairing damaged tissues.

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