Evan Ulrich demonstrates the robotic samara. The researchers noted that the concept of a single-wing rotating aircraft is not new, with the first such vehicle being flown in 1952 by Charles McCutchen near Lake Placid, New York. Since then, several other single-winged rotating aircraft have been developed, but none of these designs has used autorotation or been based on the samara. Spiraling Flight of Maple Tree Seeds Inspires New Surveillance Technology (w/ Video) Citation: Researchers build flying robotic ‘tree helicopter’ (w/ Video) (2011, January 25) retrieved 18 August 2019 from https://phys.org/news/2011-01-robotic-tree-helicopter-video.html Explore further A natural samara is positioned next to the smallest and lightest robotic samara constructed to date. The wing of the vehicle is similar in size to a natural samara wing. Image credit: Ulrich, et al. 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.
More information: Alban Urvoy et al. Direct Laser Cooling to Bose-Einstein Condensation in a Dipole Trap, Physical Review Letters (2019). DOI: 10.1103/PhysRevLett.122.203202H. J. Lee et al. Raman Cooling of Atoms in an Optical Dipole Trap, Physical Review Letters (2002). DOI: 10.1103/PhysRevLett.76.2658K. B. Davis et al. Bose-Einstein Condensation in a Gas of Sodium Atoms, Physical Review Letters (2002). DOI: 10.1103/PhysRevLett.75.3969M. H. Anderson et al. Observation of Bose-Einstein Condensation in a Dilute Atomic Vapor, Science (2006). DOI: 10.1126/science.269.5221.198 Journal information: Physical Review Letters © 2019 Science X Network In past physics research, Bose-Einstein condensation (BEC) by direct laser cooling was an often pursued, yet highly elusive goal. It was first attempted by Steven Chu, who won the Nobel Prize for laser cooling, and around 1995 by Mark Kasevich, who did not succeed at the time. Other groups led by Carl Wieman and Eric Cornell, and by Wolfgang Ketterle, all Nobel Prize laureates for BEC, succeeded in achieving BEC using evaporative cooling instead. Eventually, most researchers gave up on trying to produce BEC using laser cooling alone, up until this ground-breaking new study. “A few years ago, I had an idea of how to reduce the main obstacle to laser cooling of atoms, the light-induced formation of molecules from atoms, by using specific laser frequencies,” Vladan Vuletić, one of the researchers who carried out the study, told Phys.org. “Compared to cooling through evaporation, laser cooling had the potential to be faster and more efficient, resulting in reduced constraints for the experimental setup.”Laser cooling atoms entails carefully positioning a set of lasers and tuning them to slow down the motion of the atoms by kicking them with photons. This technique is commonly used to create cold clouds of atoms, but using it to create samples of cold atoms with a high enough density for BEC had so far proved very challenging. A key reason for this is that laser light can photoassociate neighboring atoms into molecules, which then leave the atom trap. “We found that we could dramatically reduce atom losses by deliberately choosing the energy of the pumping laser to mismatch the amount of energy required to form molecules,” Vuletić explained. “Combined with a carefully optimized sequence of so-called Raman cooling (first demonstrated by Chu and Kasevich), this allowed us to produce a cold cloud of atoms with a density high enough to create a moderately sized BEC in about one second of cooling.”In their study, Vuletić and his colleagues trapped atoms in a crossed optical dipole trap and cooled them using Raman cooling, with far-off-resonant optical pumping light to reduce atom loss and heating. This technique allowed them to reach temperatures significantly below the effective recoil temperature (the temperature scale associated with the recoil momentum of a photon), on a time scale that is 10 to to 50 times faster than the typical evaporation time scale. “Such a fast production of BEC is already on par with the very best evaporation techniques, which were optimized for speed, highlighting the potential of the new laser cooling technique,” Vuletić said. “Our laser cooling method should be applicable to other species of atoms in the future, as well as to cooling of molecules. Our faster method yields better signal-to-noise ratio, and enables new experiments to study quantum gases that were difficult to perform before.”The new method introduced by Vuletić and his colleagues could have numerous implications for future physics research. For instance, it could enable the fast production of quantum degenerate gases in a variety of systems, including fermions. In their current work, the researchers are using their system to study 1-D quantum gases with attractive interactions, which should theoretically collapse but are instead stabilized by quantum pressure. “In the future, we would like to apply the same technique to fermionic atoms,” Vuletić said. “Fermionic atoms do not condense, but avoid each other, and instead form a so-called quantum degenerate Fermi gas at low temperatures. Such systems can be used to study electrons (which are also fermions) in solid-state systems, e.g. in order to understand the nature of magnetism and high-temperature superconductivity.” Explore further Physicists develop faster way to make Bose-Einstein condensates Researchers at the MIT-Harvard Center for ultracold atoms and research laboratory of electronics have proposed a new method for producing 3-D Bose-Einstein condensates using laser cooling only. In their study, featured in Physical Review Letters, they demonstrated the efficacy of their technique in producing Bose-Einstein condensates, achieving temperatures that are well bellow the effective recoil temperature. , Science 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. Citation: A method for producing 3-D Bose-Einstein condensates using laser cooling (2019, June 3) retrieved 18 August 2019 from https://phys.org/news/2019-06-method-d-bose-einstein-condensates-laser.html Credit: Urvoy et al.
Kolkata: To mark the International Level Crossing Awareness Day and to bring awareness regarding safety at railway level crossings, Eastern Railway’s Howrah Division observed Safety Awareness Campaign at Masagram station on June 7. The basic objective of the awareness campaign was to educate people about the dangers of passing unmanned level crossings without caution. Awareness campaigns were conducted among school and college students, as well as in the Panchayats. Around 600 school students, scouts and guides, civil volunteers and local residents of Masagram participated in the campaign. Awareness campaigns were also conducted amongst road users at various unmanned level crossing gates and vehicle drivers.
Kolkata: An EMU local today hit the buffer at Ranaghat station after overshooting the platform, but there was no injury to anyone as the train was at a very slow speed, an Eastern Railway spokesman said. The suburban local train from Sealdah was to terminate at Ranaghat and was travelling at 5 km per hour when it hit the buffer at the station in Eastern Railway’s Sealdah Main section at 7.40 am. “There was no injury to anyone or damage to the train owing to its slow speed,” ER spokesman R N Mahapatra said, adding that a man was detained for allegedly distracting the motorman (driver) of the train. Also Read – Heavy rain hits traffic, flights Senior ER officials including the divisional railway manager of Sealdah went to Ranaghat station, which is 73 kms from here, soon after the accident. An inquiry has been initiated and anyone found guilty in any manner will be punished, he said. Mahapatra said that the motorman claimed that a mentally deranged man had boarded the train in the passenger section adjacent to his cabin and was creating a ruckus that distracted him. The man was detained by the GRP at Ranaghat and an investigation was being held to ascertain the fact, the spokesman said. Concrete or metal buffers are erected at the end of platforms at terminating stations or at the end of diverting tracks at other stations in order to stop trains in such circumstances where the locomotive fails to stop at a designated point.
National Book Trust, India organised a workshop on Developing Books on Yoga for Children and Young Readers in the run up to the celebrations of the first International Day of Yoga. The workshop was held at NBT Conference Hall in the Capital on June 19.“I am pleased to connect with health, peace and reading,” said Kiran Mehra Kerpelman, the Director of United Nations Information Centre for India and Bhutan, who was the Guest of Honour on the occasion. Also Read – ‘Playing Jojo was emotionally exhausting’Talking about the benefits of the Yoga, she said, “Stress is chronic in this age. Physical inactivity leads to lifestyle diseases like cancer. Yoga helps in bringing peace of mind and health.” She added that books are powerful medium to make people aware about benefits of Yoga.Prof Ramesh Bijlani,
In collaboration with Delhi Metro Rail Corporation (DMRC), Sahitya Akademi launched its second metro book shop on Wednesday at the Vishwa Vidyalaya Metro Station. Vishwanath Prasad Tiwari, the president of Sahitya Akademi inaugurated the Vishwa Vidyalaya Bookshop.The metro bookshops are part of Sahitya Akademi’s continued efforts to carry the best of Indian literature in 24 Indian languages to more readers in urban spaces where time is the main constraint and Delhi metro’s efforts to enhance cultural awareness of its passengers. The Vishwa Vidyalaya Bookshop has dedicated itself with the purpose of enabling Delhi University students to avail the benefits of the bookshop. The Sahitya Akademi Metro Bookshops will be open five days a week from 10 am to 6:30 pm, Monday to Saturday. A joint initiative by Sahitya Akademi and Delhi Metro Rail Corporation had launched the first Akademi bookshop at Kashmiri Gate Metro Station on February 5.
Published in the journal Nature, the scientists reported an in-depth analysis of human embryos created using the new technique designed to reduce the risk of mothers passing on mitochondrial disease to their children, which is debilitating and often life-limiting.Mitochondrial disease is a chronic, genetic disorder that occurs when the mitochondria of the cell fail to produce enough energy for cell or organ function, according to MitoAction, a US-based organisation working to improve quality of life for adults and children affected by the disease. Also Read – ‘Playing Jojo was emotionally exhausting’The new technique, called “early pronuclear transfer,” involves transplanting the nuclear DNA from a fertilised egg into a donated egg, which contains healthy mitochondria, on the day of fertilisation.Results of the study involving over 500 eggs from 64 donor women indicate that the new procedure does not adversely affect human development and will greatly reduce the level of faulty mitochondria in the embryo. The results suggest that the technique will lead to normal pregnancies whilst also reducing the risk of babies having mitochondrial disease. “This study using normal human eggs is a major advance in our work towards preventing transmission of mitochondrial DNA disease,” said co-author of the paper, Professor Doug Turnbull, Director, Wellcome Trust Centre for Mitochondrial Research in Britain. “The key message is that we have found no evidence of the technique being unsafe. Embryos created by this technique have all the characteristics to lead to a pregnancy,” Turnbull noted. Also Read – Leslie doing new comedy special with NetflixOnce licensed, the new technique would allow couples affected by mitochondrial disease to have the choice of whether to use pronuclear transfer to try and have healthy children.“Having overcome significant technical and biological challenges, we are optimistic that the technique we have developed will offer affected women the possibility of reducing the risk of transmitting mitochondrial DNA disease to their children,” said senior author of the study Mary Herbert from Newcastle University in England.
Internet searches for ‘how to commit suicide’ spiked right after the release of Netflix’s controversial series ’13 Reasons Why’, a show that depicts a teen girl who takes her own life, a study has found. The season finale of the teen drama shows a 17-year-old student Hannah Baker committing suicide.Researchers from San Diego State University in the US found that all suicide-related queries were 19 per cent higher than expected following the release of the finale episode. Also Read – Add new books to your shelfSome of that bump came from a higher-than-expected number of searches for phrases like “suicide hotline” (up by 12 per cent) or “suicide prevention” (up by 23 per cent).However, an alarming percentage of the spike also came from phrases like “how to commit suicide” (up by 26 per cent), “commit suicide” (up by 18 per cent) and “how to kill yourself” (up by nine per cent), researchers said.”In relative terms, it is hard to appreciate the magnitude of the release of 13 Reasons Why. In fact, there were between 900,000 and 1.5 million more suicide-related searches than expected during the 19 days following the series’ release,” said Mark Dredze, professor at Johns Hopkins University in Baltimore in the US. Also Read – Over 2 hours screen time daily will make your kids impulsiveIt is not clear whether any of those searches led directly to suicides, but previous research has found that increases in internet searches for suicide methods are correlated with actual suicides, researchers said.”While it is heartening that the series’ release concurred with increased awareness of suicide and suicide prevention, our results back up the worst fears of the show’s critics,” said John W Ayers, associate professor at San Diego State University. “The show may have inspired many to act on their suicidal thoughts by seeking out information on how to commit suicide,” he said.Researchers looked at data from Google Trends, a public archive of aggregated internet searches. The team focused on searches originating from the US between March 31, 2017, the series’ release date, and April 18.They collected all search phrases containing the word “suicide,” except for those accompanied by the word “squad,” as those were most likely for the unrelated movie Suicide Squad, released around the same time.
Gulzar, the multifaceted genius – poet, lyricist, film maker, and elocutionist – is coming to town. Gulzar will be releasing two of his books besides gracing an exhibition on him on August 26. Gulzar was introduced to the Bengali literature when he first met Tagore through his book. Now it’s time to release two of his books in Bengali. One of the books is Pantabhate which is basically revolving around his remembrance of some great Bengali personalities that he met during his creative journey like Satyajit Ray, Kishore Kumar, Suchitra Sen, Uttam Kumar, Mahashweta Devi and so on. Also Read – Add new books to your shelfThe other book is Pluto, a book of his poetry translated in Bengali. Gulzar said, “There were many small poems, which never got a room in any of my earlier books, finally they found expression with Pluto.” Both the books are being published by Dey’s Publishing and will be launched by eminent poet Shankha Ghosh and noted filmmaker Sandip Ray. This will be followed by an adda session ‘Guftgu with Gulzar’ with Shantanu Moitra, Srijato in attendance. The launch will be held on August 26, at Nandan I. Also Read – Over 2 hours screen time daily will make your kids impulsiveSubhamkar Dey of Dey’s Publishing told Millennium Post, “Pluto is his latest poetry book and we are providing the Bengali translation as well as the Urdu version in Bengali. The second book is a rare gem with the poet’s recollection of noted Bengali personalities like Bimal Ray, Tarun Mazumdar, Basu Chatterjee, Hemanta Mukhopadhyay, Bhimsen Joshi, Samaresh Basu and so on. Also he stayed at Hemanta’s place in Kolkata for 9 months.” Each book is priced at Rs 199 but if you book by August 24, you get a free booklet on Gulzar and you get both the books for Rs 300.What’s more? A rare exhibition on Gulzar will be held for the first time in city between August 26 and August 27 at Nandan IV. It will feature many rare documents like film posters, booklets, record covers, photographs, book covers on the poet and so on.