Month: August 2019

Atomic Coilgun Halts Supersonic Beams

center_img The experimental set-up. Image credit: Narevicius, et al. ©2008 APS. “An important feature [of the atomic coilgun] is its simplicity, with copper wire coils driven by discharging capacitors,” Raizen said.As an atom moves into the center of a coil rather than in between coils, it experiences a stronger magnetic field and gains potential energy. But when the coil’s field is turned off with the atom in the center, the atom loses much of its kinetic energy. The loss happens quickly: when the current is switched off, a coil’s 5-tesla magnetic field decreases by about 80% in 6 microseconds.“The amount of energy that is removed per stage is equal to the height of the magnetic hill,” Raizen said, explaining that the exact amount of energy depends on the type of atom. “We remove 1/64 of the atom’s kinetic energy per stage.”As the researchers explain, the timing sequence of the coils is important. If a coil’s field is switched off when an atom is positioned in the center of the coil rather than in between coils, the atom experiences a stronger magnetic field and is slowed more. However, switching the magnetism off when atoms are in between coils allows more atoms to be slowed. The ability to dramatically slow and stop a supersonic atomic beam could enable researchers to study atomic and molecular properties in great detail. The group is currently working on trapping and cooling atomic hydrogen isotopes, such as tritium. Analyzing tritium could enable researchers to make precise measurements of beta decay, which in turn could provide a way to determine neutrino rest mass – one of the greatest unanswered questions in physics.Other possible applications include using the atomic coilgun to trap several types of cold atoms, opening up new directions in cold chemistry. Stopping atoms such as iron and nickel could enable controlled deposition of magnetic quantum dots, and might also serve as a method for magnetic storage. More information: Narevicius, Edvardas; Libson, Adam; Parthey, Christian G.; Chavez, Isaac; Narevicius, Julia; Even, Uzi; and Raizen, Mark G. “Stopping Supersonic Beams with a Series of Pulsed Electromagnetic Coils: An Atomic Coilgun.” Physical Review Letters 100, 093003 (2008). Copyright 2008 All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of Explore furtherlast_img read more

Six net neutrality principles proposed

first_img FCC Chairman, Julius Genachowski, said rules on net neutrality are necessary to protect innovations on the Internet and to preserve the kind of openness that has allowed the Internet to flourish. He said there have been situations in which ISPs have degraded data streams or even blocked access to lawful applications, and fair rules are necessary to avoid the potentially damaging consequences of having the openness of the Internet diminished. Opponents, on the other hand, say the Internet has grown so rapidly because of the lack of rules and regulations, and that rules are not needed. Some opponents have also suggested that introducing rules could set a precedent for other countries to introduce regulations covering Internet use.The principles suggested are that ISPs should allow users to:1. send and receive all lawful content2. use all lawful services and applications3. use all lawful devices that do not damage the network4. access all network, service, content and application providersThe principles will also ensure ISPs:5. do not discriminate against lawful content, services, applications, or devices6. reveal any practices that could limit the previous five principlesThe rules have been sought by many large Internet companies such as Google, Facebook and, many consumer advocacy groups such as Free Press and Public Knowledge, many members of the FCC, and Internet pioneers like David Reed and Vint Cerf. Supporters say that without rules ISPs will change their price structures to tiered systems with the highest level services out of the financial reach of many entrepreneurs wishing to start their own Internet businesses. Those in favor of rules are also worried that without them some applications, such as VoIP, could become unaffordable or could even be banned for many people, thus reducing their voice call options.Opponents to proposed net neutrality rules include Internet providers such as Verizon and AT & T, who say the rules would prevent them charging more for premium services, and the higher charges provide the incentive for the investment in network upgrades to boost performance. The result could be either more expensive rates across the board, or paying for Internet traffic by the byte. The proposed FCC rules would also have effects on businesses, especially those with a well-developed Internet presence. Higher flat rates would push up Internet access costs for business and customers alike, and could result in a decrease in demand for online services because of their increased expense. This could have especially serious effects on businesses such as websites selling high definition video downloads.If the FCC’s six principles are adopted the effects on home users could be higher monthly charges or higher costs for downloads, but they would still be able to make phone calls using Internet services such as Skype, which would not be blocked. If the rules are not adopted, ISPs are likely to limit bandwidth and VoIP (especially as some large ISPs are also voice carriers, which are threatened by online phone services).Republican Senator John McCain (Ariz), is opposed to the rules, and has introduced a bill to block them, while President Barack Obama has placed net neutrality rules as among his top priorities. A vote on the proposed rules will take place in 2010.© 2009 Citation: Six net neutrality principles proposed (2009, October 26) retrieved 18 August 2019 from The Federal Communications Commission (FCC) in the U.S. voted last week to start a process to formulate rules that could force Internet Service Providers (ISPs) to uphold six principles that would preserve net neutrality, or what the FCC terms “open Internet”. Explore further Partial map of the Internet based on the January 15, 2005 data found on Each line is drawn between two nodes, representing two IP addresses. Image: Wikimedia Commons. Net neutrality rules face mounting GOP opposition 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.last_img read more

Pair claim they have turned hydrogen to metal

first_img Explore further Citation: Pair claim they have turned hydrogen to metal (2011, November 15) retrieved 18 August 2019 from More information: Conductive dense hydrogen, Nature Materials (2011) doi:10.1038/nmat3175AbstractMolecular hydrogen is expected to exhibit metallic properties under megabar pressures. This metal is predicted to be superconducting with a very high critical temperature, Tc, of 200–400 K, and it may acquire a new quantum state as a metallic superfluid and a superconducting superfluid2. It may potentially be recovered metastably at ambient pressures. However, experiments carried out at low temperatures, T<100 K, showed that at record pressures of 300 GPa, hydrogen remains in the molecular insulating state. Here we report on the transformation of normal molecular hydrogen at room temperature (295 K) to a conductive and metallic state. At 200 GPa the Raman frequency of the molecular vibron strongly decreased and the spectral width increased, evidencing a strong interaction between molecules. Deuterium behaved similarly. Above 220 GPa, hydrogen became opaque and electrically conductive. At 260–270 GPa, hydrogen transformed into a metal as the conductance of hydrogen sharply increased and changed little on further pressurizing up to 300 GPa or cooling to at least 30 K; and the sample reflected light well. The metallic phase transformed back at 295 K into molecular hydrogen at 200 GPa. This significant hysteresis indicates that the transformation of molecular hydrogen into a metal is accompanied by a first-order structural transition presumably into a monatomic liquid state. Our findings open an avenue for detailed and comprehensive studies of metallic hydrogen.via RCS © 2011 On the path to metallic hydrogen Journal information: Nature Materialscenter_img Protium, the most common isotope of hydrogen. Image: Wikipedia. One of the problems in attempting to say whether something is a metal or not, is the somewhat flimsy criteria used to describe just what exactly a metal is. Most dictionaries describe it loosely as an electropositive element that probably should be shiny, a good conductor of both heat and electricity and should be malleable to some degree. And of course, common sense says that it probably ought to be solid at some temperature or pressure. And that’s the crux of the matter in trying to get hydrogen to look and act like a solid. All manner of people have subjected it to either or both and have failed to produce anything that most would say is a metal and that’s why this latest attempt by Eremets and Troyan has met with less than wild enthusiasm in the science world.Regardless, they say that when they put a sample of hydrogen in a alumina-epoxy gasket that they put inside of a diamond anvil cell, an arrangement that allowed them to test the opacity via laser and the electrical resistance using electrodes, they found that without heating or cooling and at a pressure of 220GPa, the sample clouded to the point of becoming opaque and began to demonstrate an ability to conduct electricity. Next, the temperature was lowered to 30K and the pressure increased to 260GPa where they found an electrical resistance increase of 20 percent, before it leveled off. This the team says, shows the sample displaying metallic attributes.Others will of course have to duplicate the process and find the same results, and if they do, then discussions will likely ensue among the scientific community to determine if what was observed can truly be used to claim that the process does indeed turn hydrogen into a metal.On the other hand the whole point might be made moot by the simple fact that the procedure clearly can make hydrogen conductive at room temperature, which means it could conceivably turn out to be that elusive superconductor that scientists the world over have been searching for. ( — Many have tried, but none have succeeded. For at least a hundred years, scientists looking at hydrogen have scratched their chins when musing over the fact that it, as an alkali metal, by all rights should exist as a metal under the right circumstances. But thus far, no one has been able to figure out what the right circumstances might be. Until now. Maybe. Mikhail Eremets and Ivan Troyan of the Max-Planck Institute describe in their paper published in Nature Materials, how they subjected a sample of hydrogen to high pressure and low temperature and found it then demonstrated properties generally ascribed to a metal. 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.last_img read more

Researchers achieve nearperfect absorption of sounds waves

first_img(a) Schematic cutoff view of the flat panel composite absorber. Based on the parameters in Table I , the associated responses are given by Eqs. (2) and (4) as shown in (b) for the dipolar response and (c) for the monopole response. Solid curves stand for theory, and open circles are predictions based on parameters retrieved from experiments. Credit: Appl. Phys. Lett. 107, 104104 (2015); DOI: 10.1063/1.4930944 Journal information: Applied Physics Letters Explore further Materials scientists devise window that mutes sound but allows air to pass through Citation: Researchers achieve near-perfect absorption of sounds waves (2015, September 16) retrieved 18 August 2019 from (—A team of researchers at Hong Kong University of Science and Technology has found a way to create a material that is near perfect at preventing sound waves from passing through it. In their paper published in Applied Physics Letters, the team describes the theory behind their idea, the technique they used, two products they produced and how close to near perfection they came.center_img Technically, the material created by the team does not absorb sound, instead it scatters sound waves and then dissipates them, resulting in sound wave reduction of 99.7 percent. To achieve this feat, the team used two decorated membrane resonators (DMRs) built together, both of which were tuned to the same frequency. The impedance of both was set to match the environment, which was normal air.Typically, materials used to prevent noise from passing from one environment to another combine several ingredients, each of which is designed to absorb a certain frequency—the problem with this approach is that it does not stop all frequencies, because that would require too many ingredients (causing the thickness of the finished product to grow beyond usefulness). Using resonators allowed the researchers to get around this limitation—those used were made to vibrate naturally based on the object to which they were affixed. The first resonator caused sound waves to be canceled out, but because it also scattered some of its own frequencies, a second resonator was added to scatter those from the first. The result was a single layer material that offers near perfect absorption of sound waves, notably, including those at very low frequencies.The team assembled two sound muting materials based on their concept, both of which used DMRs. The first consisted of a flat panel along with dual coupled DMRs—the second one was based on a ventilated short tube that contained a DMR and a DMR backed cavity sidewall. Both achieved near perfect absorption, proving their theory correct.Presumably, materials created using the new technique could be used in situations that require restriction of a wide range of frequencies, such as recording studios, audio laboratories or even perhaps in headphones, speakers or earbuds. More information: Subwavelength total acoustic absorption with degenerate resonators, Appl. Phys. Lett. 107, 104104 (2015); report the experimental realization of perfect sound absorption by sub-wavelength monopole and dipole resonators that exhibit degenerate resonant frequencies. This is achieved through the destructive interference of two resonators’ transmission responses, while the matching of their averaged impedances to that of air implies no backscattering, thereby leading to total absorption. Two examples, both using decorated membrane resonators (DMRs) as the basic units, are presented. The first is a flat panel comprising a DMR and a pair of coupled DMRs, while the second one is a ventilated short tube containing a DMR in conjunction with a sidewall DMR backed by a cavity. In both examples, near perfect absorption, up to 99.7%, has been observed with the airborne wavelength up to 1.2 m, which is at least an order of magnitude larger than the composite absorber. Excellent agreement between theory and experiment is obtained. © 2015 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.last_img read more

When emotions find words

first_imgDelhi Poetry Festival recently celebrated its second season in the Capital. The four-day event  kicked off with poetry-on-wheels,  with a bus carrying both Indian and foreign poets taken across various heritage sites to finally stop at Bara Lau ki Gumbad for open mic poetry.Day two saw various eminent poets and speakers participating in English poetry at JNU. Noted among them were Sukrita Kumar Paul Abha Iyenger and Lovita Morang and poets  from UK, Australia and Canada also  among them were Donall Dempsy, Lara Taylor,Etienne Lalonde and Janice Windle. Also Read – ‘Playing Jojo was emotionally exhausting’Children’s poetry by New Leaf Poets Club – The junior segment of Poets Corner, was organised at SACAC. Enthusiastic little wordsmiths from various Delhi schools  read poetry and attended various workshops,one by Mariam Ahlawat, in the presence of proud parents and teachers . This is the first time ever, the children were offered such a big platform to read and get published in their own anthology.The finale held in PHD Chambers was also very well attended by poets and poetry enthusiasts. Bollywood lyricists, Sandeep Nath, A M Turaz and Aseem Abbasee along with some eminent poets held the audience in a trance with their verses. Poets Corner’s anthology, Lamhey was launched. Also Read – Leslie doing new comedy special with Netflix10 books were launched and 150 poets got published during this poetry festival season. More than 80 poets and speakers took the mike during these four days.The founders and organisers, Dolly Singh and Yaseen Anwer along with their team aspire to make Delhi Poetry Festival the biggest  poetry event in India.The uniqueness of the stage lies in the fact that emerging poets get a chance to get published and heard alongwith established ones.Poets Corner comprises a group of creative and talented poets, all dedicated to revive the dying art of poetry.Their aim is to bring out vibrant verses from the ink of wonderful poets across the globe.last_img read more

Will support GST if states are fully compensated Mamata

first_imgSpeaking to the media persons in New Delhi, Trinamool Congress chief, said, “We don’t have any problem with GST. It is our manifesto commitment. We are all for it. But states have to be adequately compensated. We need to be compensated otherwise Bengal will lose Rs 8,200 crore after GST roll out.”Even, though Mamata called for a conditional support, State Finance Minister Amit Mitra claimed that states were not consulted over proposed amendments to GST Bill. Also Read – Need to understand why law graduate’s natural choice is not legal profession: CJIThe government initiated legislation for the much awaited reform of the indirect tax system by tabling the GST Bill in the Lok Sabha Friday. Then an Empowered Committee of Finance Ministers of 29 States was formed for its implement. Union Finance Minister Arun Jaitley introduced the constitutional amendment bill for implementing GST contending that the object of the legislation is “the seamless transfer of goods and services across the country”.Banerjee, who is on a visit to the capital, said it was the central government which was wandering from its commitments it had given earlier on compensation. It was learnt that all the states including West Bengal will lose hefty amount of money (nearly Rs. 4,000 Crore) on account of Central Sales Tax (CST) only, if the draft Constitutional Amendment Bill on Goods and Services Tax (GST) is passed in Parliament in its present form. Also Read – Health remains key challenge in India’s development: Kovind“We are carrying a huge debt which was left behind by the Left Front government and if Center refused to compensate us by ignoring the suggestions of Empowered Committee of the State Finance Ministers then it will have a severe impact on state economy,” She said. To elaborate more to the media persons, she called up Mitra and asked him to brief the nuances of GST by putting her Cell phone on a speaker mode. Mitra said, “We we will not get the compensation then the revenue loss would come around Rs 8,200 Crore (nearly 20 per cent of the state revenue) in the first year.” Recently, Mitra has written to the chairman of the empowered committee of finance ministers A.R. Rather demanding an urgent discussion on the Constitution Amendment Bill. In GST states that consume more will be getting more tax, while producing states that export goods to other states including Bengal will be apparently on the losing side. Now, with most of the goods and services coming under the GST, the Bill also proposes to do away with the state’s power to levy tax on select items ‘declared goods’ as provided under Article 286 of the Constitution. On August 23, Union finance minister Arun Jaitley met Mamata at Nabanna in West Bengal and praised the Bengal government’s ‘approach’ on GST.TN CM urges consensus on GST, asks PM Modi to allay fearsTamil Nadu Chief Minister O Panneerselvam on Friday urged Prime Minister Modi to first allay the fears of the States’ on the Goods and Services Tax issue, go in for consensus and then consider the GST Bill’s adoption.“The Centre must ensure that the States’ fears are allayed and a true consensus is achieved before such a far reaching reform is attempted,” Panneerselvam said in a letter to Modi. “I strongly urge you against hustling through the Constitutional Amendment Bill hastily as such a move is bound to have serious long term implications for the fiscal autonomy and revenue position of the States,” he said. The Centre’s proposal to introduce a Constitutional Amendment Bill on GST and then to evolve a consensus on its various aspects like tax rates and bands was not acceptable to Tamil Nadu, he said.last_img read more

Freedom echoes

first_imgUsing newspaper imprint on aluminum, the daily clamor of information in today’s day and age is reflected from which the stenciled words emerge in a golden luster. The auditory impulse of the work transforms the place into a meditative and introspective zone. The idea behind it is that the bludgeoning sound levels enveloping us in our daily urban charade is slowly silencing the peace and tranquility of our times. Today, it is the noise of urban, metropolis hurry and flurry that brings consolation to many, for it keeps them away from the demons of their actions, which they have to face when surrounded by silence. Also Read – ‘Playing Jojo was emotionally exhausting’The size of pipe of the outer frame is-10″diameter, the chimes-height is 8ft x 10″diameter, made out of aluminum, silkscreen print, airbrush on stencil and drawing using pen and ink. iron, metal,  wood and metal paints. Painted over the cylindrical metallic tubes, are words that people, things and objects that have made a difference in people’s lives have written either in Hindi or in English. A softheaded hammer is also kept at the audience’s disposal to strike the tubes with.Sounds of Freedom believes, “Gender is not just a woman’s problem, it is a man’s as well. Let’s stand together in the fight for gender equality and freedom of creative expression” This was the inspiration for most activities on the occasion.last_img read more

Yeddyurappas resignation victory of democracy Mamata

first_imgNew Delhi: West Bengal Chief Minister Mamata Banerjee on Saturday congratulated former Prime Minister and JD-S Chief H.D. Deve Gowda, party leader H.D. Kumaraswamy and the Congress after B.S. Yeddyurappa announced his resignation as the Karnataka Chief Minister before facing a crucial trust vote in the state Assembly, and called it a “victory of democracy”. “Democracy wins. Congratulations Karnataka. Congratulations Deve Gowdaji, Kumaraswamyji, Congress and others. Victory of the ‘regional’ front,” Mamata tweeted. Also Read – Heavy rain hits traffic, flightsMamata’s remarks came just after Yeddyurappa announced his resignation in the Karnataka Assembly in an emotional speech, saying “the BJP didn’t get the numbers needed to prove majority in the House”.The resignation comes two days after Yeddyurappa took oath as the 15th Chief Minister of the state.The May 12 election across the state in 222 constituencies of the 225-member assembly, including one nominated, threw up a hung House, with no party securing majority. Polls in two constituencies were deferred.Of the 222 seats, the BJP won 104, the Congress 78, the Janata Dal-Secular, 37 and one each was bagged by the Bahujan Samaj Party, the Karnataka Pragnyavantha Janatha Party and an Independent. As JD-S leader H.D. Kumaraswamy won from both Channapatna and Ramanagaram segments, the party’s effective strength in the House was 36.last_img read more

A festival of sweets and prayers

first_imgFestivals are delightful traditions in any faith as they remind us to take time out from our hectic lives and focus on issues beneficial to us and also the people around us. Eid is an Arabic word meaning ‘festivity’, while Fitr means ‘to break the fast’ and hence the celebration symbolizes the breaking of the fasting period. Eid-ul-Fitr is one of the two major festivals in the Islamic calendar. The celebration of Eid-ul-fitr starts with the beginning of the Islamic month of Shawwal, which is the 10th month of the lunar Islamic calendar and the end of the Islamic holy month, Ramadan. It is a time to bestow charity on those in need and celebrate with family and friends, the completion of a month filled with blessings and joy. It is not possible to predict the date of Eid-ul-Fitr, accurately.  Also Read – ‘Playing Jojo was emotionally exhausting’The sight of the crescent moon marks the end of Ramadan and the beginning of Eid celebrations. The new moon may be sighted earlier or later in specific locations. Therefore, many Muslims residing in different countries, for example in USA and Canada, sometimes begin the celebrations on different dates.Charity is the core of Ramadan and Eid, when each Muslim family gives a determined amount as a donation to the poor. This donation is in terms of food like, rice, barley, dates among others, to ensure that the needy can have a full meal and participate in the celebration.   Also Read – Leslie doing new comedy special with Netflix“At the end of Ramadan we pay Zakat al-Fitr (special fast breaking alms) as a token of thankfulness to God for enabling him or her to observe the obligatory fast,” said Saba Siddiqui. Eid ul-Fitr is sometimes called the ‘Sweet Holiday,’ since desserts are usually taken, celebrating the end of the Ramadan fasting. People buy variety of items which includes gifts, sweets, food items and other things before Eid. Buying new clothes for Eid is a prevalent tradition, and those who can’t afford it, make an effort to look their best.  On the night before Eid, female members decorate their hands with henna and are encouraged to dress in their best clothes for the occasion. This festival has a feeling of brotherhood and everyone celebrates it by hugging each other on this day regardless of caste or creed. This festival is not only enjoyed by Muslims but also by the Non-Muslims. “We get dressed and go to our Muslim friend’s place. Over there, we get to eat mouth-watering Biryanis and Sewiahs,” says Siddhant Pal.Muslims are not allowed to fast on Eid ul-Fitr, since they are celebrating the end of fasting. Eating food before attending the prayer is encouraged. Special Eid prayers are held in the early morning of the holiday, usually at a large central mosque, an open field, or a stadium.  After the prayer is completed, worshippers embrace each other and say ‘Eid Mubarak,’ or ‘Blessed Eid,’ to wish each other goodwill. It is customary to give money to children, cousins, nieces, nephews (termed Eidi).After the Eid prayers, families often visit their neighbouring houses and extended relatives to wish them a happy holiday and exchange gifts.last_img read more