For peacocks, the eyespots don’t lie © 2014 Phys.org Journal information: Proceedings of the Royal Society B This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Nacre is valuable for two reasons; the first is because it is pretty—oftentimes it looks like a colorful painting technique; it is also the material that gives pearls their unique coloring patterns. The second reason is because nacre is also very strong and crack resistant which makes it useful in a variety of industrial applications. In this latest effort to create the material from scratch the researchers developed a process that very closely mimics how it is done naturally.In nature, nacre is a material made of tiny aragonite slabs held together by a fibrous gel—similar in structure to fish scales. To make their own version, the team created a subdivided container into which they poured a chitosan solution. The container with the fluid in it was then frozen and then vacuum dried. The mixture was then allowed to mineralize over the course of a few weeks—each section in the container formed into an individual plate of synthetic nacre. The result was not colorful like mother-of-pearl though, because the plates were thicker, but they very much resembled the real material. Close inspection of the faux nacre revealed that the plates were larger than those made naturally which at times caused some to pop out of place, which of course made the material less resistant to cracking. But the development of the technique has shown a new way to make the material, the team reports, and suggests that it might be used as part of a 3-D printing process. Though it is not likely that such materials will be used to make jewelry anytime soon, it does appear possible that some will very soon be used to make new kinds of strong composites. © 2016 Phys.org More information: L.-B. Mao et al. Synthetic nacre by predesigned matrix-directed mineralization, Science (2016). DOI: 10.1126/science.aaf8991 Explore further Mother-of-pearl’s genesis identified in mineral’s transformation Citation: A new way to make synthetic mother-of-pearl (2016, August 19) retrieved 18 August 2019 from https://phys.org/news/2016-08-synthetic-mother-of-pearl.html Journal information: Science Press release Electron microscopy image of a fractured surface of nacre. Credit: Fabian Heinemann/Wikipedia A team of researchers from several institutions in China and Germany has found a way to create a synthetic type of nacre—more commonly known as mother-of-pearl. In their paper published in the journal Science, the team describes how they sought to emulate the way nacre is produced in nature and in so doing came up with a method that allows for the creation of a material that is very similar to the linings found inside of some mollusks.
© 2017 Phys.org The researchers, Anastasiia Krushynska and Federico Bosia at the University of Torino; Marco Miniaci of the University of Le Havre; and Nicola Pugno at the University of Trento, Queen Mary University of London, and Italian Space Agency, propose a new approach to this problem in a recent issue of the New Journal of Physics.”This work provides a new promising approach to obtain low-frequency noise attenuation,” Pugno told Phys.org. “The strategy is based on the design of acoustic metamaterials, which combine the advantages of a spider web-like geometry and the space-coiling approach of labyrinthine channels. This structure also provides a simple and reliable way to introduce tunability in sound manipulation, which is highly desirable for practical applications.”As low-frequency sounds are characterized by long wavelengths, shielding these acoustic waves typically requires very thick, heavy structures that are expensive and impractical for most applications. An alternative approach is to use recently developed metamaterials. Whereas traditional acoustic barriers rely on the composition and thickness of the material to manipulate sound, metamaterials do this with their intricate subwavelength-scale structure. As a result, metamaterials can be very thin, yet may still effectively reduce and manipulate low-frequency sounds.In the new study, the researchers based their design on a new concept called labyrinthine metamaterials or “space coils,” first proposed a few years ago. Labyrinthine metamaterials consist of layers of folded zig-zag channels rotated relative to each other, giving them a maze-like appearance.One such labyrinthine metamaterial is configured in the form of a spider web. The authors of the current study recently showed that this geometry is particularly efficient in attenuating (or reducing the intensity of) elastic waves. Now in their new study, the researchers modified the previously proposed labyrinthine metamaterial design by adding a square frame, so that the resulting structure resembles a conventional spider web, and showed that this simple modification creates air cavities that allow for variation in the widths of each channel in the web. By controlling the channel widths, the researchers showed that it is possible to tune the metamaterial’s acoustic properties, including the way in which it disperses and reflects sound waves.The researchers expect that the spider-web-structured metamaterial, which is designed to be made of aluminum, can be easily manufactured, making it potentially useful for a wide variety of applications that involve low-frequency sound manipulation. “Though similar geometries have shown promise for the attenuation of low-frequency vibrations, the developed metamaterials cannot be applied directly to seismic shielding, since they manipulate acoustic (airborne) and not elastic waves,” Pugno explained. “Their applications include the control of low-frequency sound and noise isolation that remain challenging with traditional approaches, as well as transformation acoustics and sound focusing, such as in concert halls.” This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Journal information: New Journal of Physics (Left) Photo of a natural spider web (by D. Krushinsky), along with illustrations of spider web-structured acoustic metamaterials (center), and figures of their acoustic dispersion and transmission spectra (right). Credit: Krushynska et al. ©2017 IOP Publishing More information: A. O. Krushynska, F. Bosia, M. Miniaci, and N. M. Pugno. “Spider web-structured labyrinthine acoustic metamaterials for low-frequency sound control.” New Journal of Physics. DOI: 10.1088/1367-2630 Explore further Citation: Spider-web ‘labyrinths’ may help reduce noise pollution (2017, October 17) retrieved 18 August 2019 from https://phys.org/news/2017-10-spider-web-labyrinths-noise-pollution.html Sound-proof metamaterial inspired by spider webs (Phys.org)—Researchers have demonstrated that the geometry of a natural spider web can be used to design new structures that address one of the biggest challenges in sound control: reducing low-frequency noise, which is the second most widespread environmental problem in Europe after air pollution.
The braiding method in the new study consists of a four-step process that involves slowly tuning the parameters of the system that generates the Majorana time crystals. In each step, the 0 and π modes are shifted, so that at the end of the entire process, the sequence of transformations results in one complete braiding operation that resets the system to its initial configuration. In the future, time crystals may lead to new ways to perform certain quantum computational tasks. With this goal in mind, the physicists also showed that their quantum control protocol can be applied to time crystals to generate “magic states,” which are a basic requirement for quantum computing. “Braiding time crystals is potentially useful for quantum computation because we exploit their time-domain features and thus obtain more qubits for encoding information, and hence achieve savings in hardware,” Gong said.In the future, the physicists plan to further explore the possibilities of braiding time crystals. For one thing, they expect that extending braiding from one superconducting wire to an array of wires may allow them to simulate more intricate braiding processes.”Given that we have now shown how the time dimension can be used as a resource for performing quantum computation, one future direction we have in mind will be to explore the possibility of storing and manipulating information with even fewer physical resources by enlarging the system in the time direction and by making use of more Majorana modes in periodically driven quantum wires,” Gong said. “As a long-term goal, we plan to use this idea to design a robust quantum computer architecture with an optimal amount of resources—that is, one that is relatively small in physical size, but does not take a very long time to operate.” Braiding time crystals. Credit: Bomantara and Gong. ©2018 American Physical Society Physicists propose method for braiding light Over the past few years, physicists have predicted that a new form of matter called time crystals may have potential applications in quantum computing. Now in a new study, physicists Raditya Weda Bomantara and Jiangbin Gong at the National University of Singapore have taken some of the first steps toward showing exactly how that might be done. They theoretically demonstrate that, by braiding two different modes of time crystals, it’s possible to generate the states that are necessary to perform universal quantum computation. Citation: Braiding may be key to using time crystals in quantum computing (2018, June 20) retrieved 18 August 2019 from https://phys.org/news/2018-06-braiding-key-crystals-quantum.html © 2018 Phys.org Journal information: Physical Review Letters More information: Raditya Weda Bomantara and Jiangbin Gong. “Simulation of Non-Abelian Braiding in Majorana Time Crystals.” Physical Review Letters. DOI: 10.1103/PhysRevLett.120.230405Also at arXiv:1712.09243 [quant-ph] Time crystals have attracted the attention of physicists since the concept was first proposed by Frank Wilczek in 2012. Five years later, in 2017, time crystals were experimentally realized for the first time. Just as ordinary crystals are characterized by their repeating patterns in space, time crystals—which are always moving—have the unique feature that their motion exhibits repeating patterns in time. To realize a time crystal, a periodically driven laser sets the particles in a superconducting loop in motion. When the system is manipulated in a precise way, the particles’ motion collectively synchronizes in a periodic manner, resulting in a time crystal.In the new study, Bomantara and Gong have developed a method for harnessing the unique properties of time crystals for quantum computing that is based on braiding. To do this, they turned to a particular type of time crystal called a Majorana time crystal, whose name comes from the way it’s created, which is from the quantum coherence between two types of Majorana edge modes (0 and π) in a superconducting chain. The reason for choosing Majorana time crystals is that they share similarities with a type of quasiparticle called non-Abelian anyons, which can be braided and have recently been considered as a potential component of a topological quantum computer. By making use of this connection to non-Abelian anyons, the physicists showed that it’s possible to mimic non-Abelian braiding in Majorana time crystals.”Loosely speaking, braiding refers to exchanging the location of two particles,” Gong told Phys.org. “In order to carry out this exchange, the particles are to be systematically moved around each other in such a way that if we draw the paths traversed by the two particles in spacetime, they form a braid. We know in real life that there are different types of braids, and that converting one braid to another requires certain operations that nature cannot do by itself. As a result, by storing information in these different types of braids, we can manipulate this information (hence performing quantum computation) by changing one type of braid to another (hence called braiding) without worrying that some external disturbance may destroy them.” Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Once upon a time, when the smog hadn’t settled on Delhi like it does now, a wiry young man would turn his lens on history and capture them for posterity. Starting from 1966, the man — known to the world as Raghu Rai — would peel the layers of the city like one peels an onion and get to the crux of it, always coming up with shots that remain frozen in the history of time. But Rai wishes time stood still in Delhi even though he hails progress. ‘The romance of Delhi is long gone,’ he rues. Rai dislikes the way Delhi has changed over the years and feels modernisation has taken away from the essence of the city. ‘The change is directionless with no aesthetics. It is haphazard growth,’ he says, adding: ‘The ancient India feel is long gone. The modern architecture is nothing great. We are lost in between.’ Also Read – ‘Playing Jojo was emotionally exhausting’Rai has now attempted to recreate Delhi’s past, although briefly, with a solo exhibition titled Delhi… that was. The exhibition has 51 photographs which capture monuments and slices of life in a Delhi that is now lost forever to the ravages of time. He hates the chaotic construction that has happened around the monuments. ‘When I started back in 1966, there were wheat fields behind Humayun’s Tomb and behind that one could see railway tracks. That ethos and feel of old Hindustan is now gone. Progress is fine but there is no aesthetics in the cityscape anymore,’ says the ace photographer. Also Read – Leslie doing new comedy special with Netflix The photographs span four decades of Rai’s works. ‘These capture scenes of Delhi that are not possible today because the monuments, skyline and landscape have changed,’ explains curator Anubhav Nath. The works are up for sale for those interested and start at Rs 51,000. These include black and white and coloured shots on various subjects and offer a slice of both traditional and contemporary India. From Safdarjung’s tomb to Humayun’s Tomb (of which there are multiple shots capturing myriad moments), Jama Masjid and Chandni Chowk, the river Yamuna and Red Fort before it was fenced off and given the artificial driveway look — there are many photographs which document the passage of time in Delhi. So how has Delhi changed over the years? ‘The effect of globalisation is very strong. The youth is lost in that. It is a hotch potch now. The kind of clothes people wear when they go to the monuments just don’t blend anymore,’ Rai says. He is not too fond, either, of the changes that have happened inside the monuments. ‘They have just made lawns inside the monuments, nothing else,’ he rues. And which parts of Delhi still manage to attract him enough to capture them on camera? Rai lists Jama Masjid, Red Fort, the Mehrauli area, old delhi, Tughlaqabad and Old Fort as his favourites. ‘These areas still have large chunks of landscape which relate to the essence of old Delhi,’ he says. Since there is no way one can turn back time, we are only left with Rai’s images to look back with fondness at what we have lost.DETAILAt: Ojas Art, 1AQ, Qutab Minar Main Roundabout On Till: 9 DecemberTimings: 11 am to 7 pmPhone: 26644145
Summer is set to roll in and spring will get a warm farewell, the German way. Indo German Chamber of Commerce brings the carnival ‘The German Spring Fest’, the second of its edition to the city at the German House, Chanakyapuri on 30 March.The event gives an opportunity for all age groups from children to grown ups, to celebrate spring in style with fun, frolic and shopping, with an exclusive palate of lifestyle products, children’s goodies, fashion wears, designer home products, garden accessories and delectable food items.Live performance of a music band along with multi cuisine food and German ale would add to the evening’s experience. The event is expected to be attended by expat and business communities.DETAILDate: 30 MarchTime: 12 pm onwardsPlace: Indo German Chamber of Commerce, Nyaya Marg, Chanakyapuri
When we think about magic, we think of a magician pulling a rabbit out of his hat. Delhi Tourism’s third International Magic Festival presented the history of Indian magic to the audience along with experts dishing out pointers about being a mentalist.Audience consisting of mainly children along with their parents were amused to see magicians pulling things of thin air. They also got a chance to learn a few magic tricks themselves in the magic teaching classes conducted by the organisers. Also Read – ‘Playing Jojo was emotionally exhausting’The crowds was thrilled to witness the variety and the quality of magic acts in the festival. The street magic shows and stand-up magic shows were on throughout the day. Day two was marked by performance of various mentalists and their elaborate explanations about their art; they follow a doctrine that says that the mind is the true reality and that objects exist only as aspects of the mind’s awareness. A fancy dress competition was conducted on the theme of Halloween, magic and tourism where children were dressed as various spooky characters and magicians as well. It was followed by a magic competition for below 16-year-old children. Also Read – Leslie doing new comedy special with NetflixThe performances by International Magicians from Malaysia and Poland starred as the biggest attraction during the festival. Magic Quest from Malaysia performed a Classical Magic act which was based on Indian music while magician Jakub from Poland enthralled the audience with his unique stand up comedies.A special exhibition area was devoted to showcasing the artefacts of magic. The festival concluded on 29 September. Sunday with prize distributions and some more magical performances. We can’t wait for next year!
A party insider told Millennium Post that senior leaders are in a fix on whether to retain or remove Raje. Prime Minister Narendra Modi and party president Amit Shah will take a final call on the matter only after Union Finance Minister Arun Jaitley is back from his US trip.The BJP, which has been defending Raje, was on the back foot when the Congress flashed signed documents (dated August 18, 2011) by Raje, favouring Modi, in a press conference recently. The document signed by Raje and filed by Modi’s immigration attorney