Nanoscale heat engine exceeds standard efficiency limit

first_img Journal information: Physical Review Letters (Phys.org) —In 2012, a team of physicists from Germany proposed a scheme for realizing a nanoscale heat engine composed of a single ion. Like a macroscale heat engine, the theoretical nanoscale version can convert heat into mechanical work by taking advantage of the temperature difference between two thermal reservoirs. Because the single-ion heat engine is so small, at the time the physicists noted that it had the potential to tap into the quantum regime and experience quantum effects. Explore further More information: J. Roßnagel, et al. “Nanoscale Heat Engine Beyond the Carnot Limit.” Physical Review Letters. DOI: 10.1103/PhysRevLett.112.030602Also available at arXiv:1308.5935 [quant-ph] © 2014 Phys.org. All rights reserved. The heat engine’s efficiency at maximum power is shown as a function of the squeezing parameter. The results of the Monte Carlo simulations (black dots) show that the efficiency of the proposed heat engine can be increased by a factor of four when the squeezing parameter is equal to or greater than 0.4. The generalized Carnot limit is the efficiency limit for an engine interacting with a squeezed thermal reservoir. Credit: J. Roßnagel, et al. ©2014 American Physical Societycenter_img Can a car engine be built out of a single particle? Now in a new paper, the physicists, from the Universities of Mainz and Erlangen-Nürnberg in Germany, have theoretically shown that a nanoscale heat engine can take advantage of nonthermal effects. “Our theoretical and numerical findings show that the performance of quantum heat engines may be enhanced by coupling them to engineered nonthermal reservoirs, like squeezed reservoirs,” coauthor Eric Lutz, Physics Professor at the University of Erlangen-Nürnberg, told Phys.org. “These results follow from the application of the second law of thermodynamics to a reservoir configuration that is more general than usually considered in textbooks. From a theoretical point of view, they indicate that the second law is less restrictive away from equilibrium.”In their paper, the physicists showed that when the high-temperature thermal reservoir to which the quantum heat engine is attached is “squeezed,” the heat engine’s efficiency at maximum power dramatically increases and can exceed the standard Carnot limit by a factor of two. Since the power of an engine vanishes at maximum efficiency, the efficiency at maximum power is the quantity of prime interest for practical applications.As an expression of the second law of thermodynamics, Carnot’s result places a fundamental limit on a heat engine’s maximum efficiency. However, this limit holds only for the particular configuration that involves two thermal reservoirs at different temperatures. The engine proposed here has only one thermal reservoir, since the reservoir that is squeezed is considered nonthermal. While thermal reservoirs are characterized only by their temperatures, nonthermal reservoirs can be controlled in additional ways, such as by squeezing. As the physicists explain, squeezing is a quantum optics concept that has been shown to be a useful tool in high-precision spectroscopy, quantum information, quantum cryptography, and other areas. However, the use of squeezed thermal reservoirs in quantum thermodynamics has been largely unexplored until now.The physicists’ simulations showed that this heat engine can be experimentally realized with current technology involving a single ion and laser reservoirs. The simulations revealed that such a heat engine could realistically operate at maximum power with an efficiency that is up to four times larger than the efficiency obtained with two thermal reservoirs, and a factor of two above the standard Carnot limit.In the future, these dramatic improvements in efficiency through squeezing could lead to the realization of more efficient nanoengines.”We succeeded recently to trap ions and plan to verify the predicted results in the lab,” Lutz said. “We are currently investigating heat pumps and the options to scale the number of ions up.” Citation: Nanoscale heat engine exceeds standard efficiency limit (2014, January 27) retrieved 18 August 2019 from https://phys.org/news/2014-01-nanoscale-standard-efficiency-limit.html 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

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Flying without wings

first_imgFlying in from Europe to Argentina and over London at the opening ceremony of the last Olympics, they stopped over Delhi to consummate the second edition of the three months long festival of France in India, Bonjour 2013. The Jawaharlal Nehru Stadium arena was brimmed with cheering spectators overwhelmed with joy and awe.The Ambassador of France to India Francois Richier welcomed the gathering and the Indian political mavericks L K Advani , Karan Singh and Shasi Tharoor, who together with the French nationals enjoyed the acrobatic fourteen angels who swung around the Tyrolienne on an octagonal iron dome. Also Read – ‘Playing Jojo was emotionally exhausting’Flying Angels (Place des Anges), directed by Stéphane Girard and the late Pierrot Bidon, showcased angel-like acrobats suspended from zip lines who take over the aerial space and play with their weightlessness while showering white flakes on the spectatorsThe celestials welcomed the crowd with their feather flakes and flowers descended to the earthly for their affability.The French Ambassador in his welcome speech told that sky is the limit for the Indo French relationships highlighting the show as a result of the joined efforts. The angels manifested their diverse skills by performing melancholic ballet dances and nimbly juggling balls on air. Also Read – Leslie doing new comedy special with NetflixH.E. François Richier, Ambassador of France to India, said, ‘Organised in partnership with the Ministry for Youth Affairs and Sports, Flying Angels is a splendid occasion to reach out to the youth, and Bonjour India. The whole richness of Indo-French relations is expressed during this great moment. Our French and Indian artists have worked together for three months.’The angels joined the crowds to move together for the Indian Oscar sensation Jai ho in the end and posed with them for pictures of souvenir.When asked ‘What it takes to fly for a normal being?’, an angel replied ‘Fly with your heart’..Indeed they did.last_img read more

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Prithvi in Delhi

first_imgAll lovers of theatre brace up and keep the weekend free, for you don’t wanna miss out on this lovely thing coming up. The Pad- starring Kitu Gidwani, Capt. Sanjay Nath, Daniel D’ Souza and Saattvic, and is produced by Nishna Mehta – young powerhouse and one of the most sought after stage managers in Mumbai theatre. It explores relationships in contemporary India  among people belonging to communities that most people know very little of and are subject to quick stereotyping. The play looks beyond these biases of stereotype and assumption and looks at the characters for who they really are as people.The play raises questions about the nature of love and its limitations. Also Read – ‘Playing Jojo was emotionally exhausting’ About the play A house in Bandra, Mumbai is witness to two inextricably intertwined relationships between successive pairs of occupants. Pulkit, a banker, has rented a quirky flat in Bandra for the sole purpose of hooking up. One night he meets Sahil, a young PhD student, for sex. Sahil is researching interior design, and is taken by the interiors of the house. He wants to use it for his research, but has to deal with a bitter, cynical and brusque Pulkit. The one night stand turns into something more, as they get to know each other… and uncover the lives of the previous occupants, Jennifer and Fabian. Also Read – Leslie doing new comedy special with Netflix The Theatre gropup Frontier Theatre is a new Mumbai based theatre group that aims to create original and relevant theatre that pushes boundaries. Central to our philosophy is the belief that the content and form of our work should reflect and document the exciting and dynamic society we live in – a society that is trying to develop while keeping its roots intact, a society that is struggling to reconcile Eastern and Western values and ways of life, a society that throws up mind boggling inequalities, a society that is on the cusp of becoming a major global power. So get it booked and get going! When – June 7,2014 4:30 pm & 7:30 pm Where – Alliance Francaise de Delhilast_img read more

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Agueros late strike rescues Man City

first_imgSergio Aguero  (in pic) spared Manchester City another embarrassing defeat as the Argentine striker’s late equaliser salvaged a 2-2 draw against QPR on Saturday. Aguero netted his second goal of a dramatic encounter with just three minutes left at rain-lashed Loftus Road, but this was another alarmingly sloppy display from the struggling Premier League champions.Manuel Pellegrini’s team were well below their best again just three days after suffering a shock home defeat against CSKA Moscow that left them in danger of elimination from the Champions League. Charlie Austin had given QPR a deserved early lead and it needed an Aguero equaliser tinged with controversy to level the score before half-time. A Martin Demichelis own goal in the closing stages put second bottom QPR back in front, but Aguero remains the one bright spot in a difficult campaign for City and he came to their rescue in the final moments. Also Read – Khel Ratna for Deepa and Bajrang, Arjuna for JadejaAguero’s heroics couldn’t hide the latest in a growing list of underwhelming City displays and they need to improve quickly to catch leaders Chelsea. The champions looked bedraggled and befuddled as QPR ran riot in the early stages. Austin had the ball in the net in the eighth minute when he headed home from close-range, but the QPR forward had strayed yards offside.Remarkably Austin was denied again in bizarre circumstances from the restart. Joe Hart hit his free-kick straight to Austin, who fired home and wheeled away in celebration only for referee Mike Dean to disallowed it because the City goalkeeper had broken the rules by accidently kicking the ball twice. Also Read – Endeavour is to facilitate smooth transition: ShastriYet City failed to heed the warning of their fortunate escapes and Austin finally made them pay for some more shoddy defending in the 21st minute. Eduardo Vargas tricked his way past Clichy and cut in from the right before sending over a low cross that Austin, played onside by the ponderous Mangala, met with an emphatic strike past Hart.City drew level in ruthless fashion in the 32nd minute. Once again QPR had a grievance with the officials as Aguero made a run from a marginally offside position to brilliantly control Mangala’s long pass with a deft touch as it looped over his head. Aguero then used the slightest touch off his arm to knock the ball down for a cool finish past Robert Green. QPR then were gifted their second goal in the 76th minute. Austin whipped over a cross and when Demichelis challenged with Zamora, the Argentine defender headed into his own net. But Aguero levelled in the 83rd minute with a typically clinical finish. Toure clipped a pass through to Aguero and he showed great composure to jink around Green before cutting back to make space for a powerful shot into the corner.last_img read more

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Keys notes

first_imgThe Hungarian Information and Cultural Centre, in cooperation with Delhi Music Society and India International Centre, organized a flute-piano concert by the musical-duo Dávid Simon and János Palojtay from Hungary on January 24 at the Capital’s India International Centre Auditorium.Opening the evening, Tibor Kovács, The Director of Hungarian Information and Cultural Centre, welcomed the audience and introduced the musicians to everyone. The theme was based on classical music with the presentation of various complementing pieces by J S Bach, W A Mozart, Ferenc Liszt, Francis Poulenc, Erno Dohnányi, and Béla Bartók.  Also Read – ‘Playing Jojo was emotionally exhausting’The performance of Dávid Simon, on Flute and János Palojtay, on Piano was well accepted by the audience with the melancholic sounds and tones of their musical instruments. The dense sound and wide range of piano created a smooth amalgamation with the brilliant unity of the lyric and smooth tone of the flute. The musicians maintained an active relation with the attendees by presenting a brief explanation and relative connection of each musical piece, they played. The pianist held Kovács’s cordial support, during the performance.last_img read more

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Ferrer downs Nishikori for 4th Mexico title

first_imgDavid Ferrer won a record-equalling fourth Mexican Open title with a 6-3, 7-5 victory over Kei Nishikori in the Acapulco hardcourt final. The Spanish world number nine’s triumph put him level with Austrian Thomas Muster with four Mexican titles having also won the tournament three times from 2010-2012 on clay. It was Ferrer’s third title this year after Doha and last week’s win in Rio de Janeiro and 24th of his career, ending a run of five defeats to the Japanese top seed. Nishikori now leads Ferrer 7-4 in their meetings. “I played very aggressive, without mistakes. I’m very happy. To win here a fourth time is a dream. In important moments, he made more mistakes and I took my chances. I feel very confident with my tennis now. I’ve won three tournaments this year and we’ve only began the season,” Ferrer was quoted as saying on the ATP website.last_img read more

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Toilet at home must for govt employees in rural Chhattisgarh

first_imgImparting momentum to Prime Minster Narendra Modi’s Clean India mission, the BJP-ruled Chhattisgarh government has made it mandatory for its employees in rural areas to have toilets at their houses in order to spread awareness about hygiene in remote areas.A circular in this regard has been issued by Chief Secretary Vivek Dhand, a senior official of the state Public Relations department said on Monday.”The circular instructed that under Clean India Campaign, it is compulsory for government officials/employees posted in rural areas to build toilets in their homes and use the same,” the official said. Also Read – Need to understand why law graduate’s natural choice is not legal profession: CJISince they live among villagers, they should promote use of toilets by setting personal example of themselves and bring about a major change in the attitude of people regarding the importance of hygiene, the official said.The circular has been conveyed to the Chairman of Revenue Board at Bilaspur, Departmental Heads, Divisional Commissioners, District Collectors and CEOs of Zilla Panchayats in this regard. Also Read – Health remains key challenge in India’s development: KovindIt said under the Clean India Mission (rural), the Union Ministry of Drinking Water and Sanitation has suggested that all government, semi-government employees and those receiving honorarium for their service to the government and local bodies, posted in rural areas, should have toilets in their homes.In case any of these employees do not have toilets in their houses, they should have it within next three months, the official said. “The circular also stated that to ensure compliance to these instructions, permanent officials/employees should be made to sign affidavit and avowal that they have toilets in their houses and they are using it,” the official said.While the contractual employees’ term would only be extended when they ensure construction of toilets in their houses and submit affidavit along with avowal regarding the same, the service period of daily wagers and employees on honorarium will be extended only when they go for construction and use of toilets in their homes, he said.It also asked the departmental heads to ensure that these instructions are compulsorily followed by employees as well as teachers, police constables, anganwadi and health workers, civic officials, literacy inspirers and patwaris posted in rural areas.last_img read more

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Govt police agree upon putting end to commission system in buses

first_imgKolkata: In a bid to check bus accidents, the state government and the police have proposed to do away with the commission system in bus services.The matter was discussed in a meeting held on Tuesday. State Transport minister Suvendu Adhikari, Additional Chief Secretary Alapan Bandyopadhyay, other concerned officials of the Transport department and senior police officers held the meeting, with representatives of bus owners’ associations.Sources said that the Transport department and the police have proposed to put an end to the commission system. Under the existing system, drivers and conductors get a commission from the fare collected from passengers. As a result, buses of same routes race among themselves to get more passengers, which leads to accidents. Also Read – Heavy rain hits traffic, flightsIt may be mentioned that doing away with the commission system is an old issue and it crops up whenever there is any major bus accident. The Left Front government had remained indifferent to the issue. Now, the Mamata Banerjee government is trying to put an end to it, by removing the commission system for good.There are private buses in which there are two conductors. In such cases, the two conductors and the driver of the bus get 24 percent of the total amount of the bus fare they collect in a day. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThere are some buses, mainly the mini-buses, in which there is one conductor and a helper. In such cases, the driver gets 14 percent and conductor gets 9 percent of the total fare collected, while Rs 250 is given to the helper per day.The commission system is in place only in five districts, namely Kolkata, Howrah, Hooghly and North and South 24-Parganas. In all other districts, the driver and conductor get salaries at the beginning of every month from bus owners.Representatives of the bus owners’ associations have urged the state Transport department to frame a guideline in this connection.last_img read more

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46yearold rickshaw puller commits suicide over domestic dispute

first_imgKolkata: A 46-year-old rickshaw puller was found hanging from the bamboo ceiling at his residence on Lockgate Road near the railway siding in Chetla on Saturday night.As per preliminary probe by the police, the victim Tapan Debnath hanged himself. According to local sources, Debnath was a drunkard and used to quarrel with his wife over his alleged inability to earn a decent living. He returned at around 10 pm on Saturday and had a heated exchange with his wife. After the quarrel, his wife went out for some work. Also Read – Rain batters Kolkata, cripples normal lifeThe victim’s mother, who works as a domestic help at a nearby residence, returned home at around 11.15 pm and found Debnath hanging with the help of a dupatta. The woman raised a cry and the person was rushed to MR Bangur hospital where he was declared brought dead. “We have noticed no external injury on the body of the deceased. Locals have informed us of the family discord. It appears to be a case of suicide. We are waiting for the post-mortem report to ascertain the cause of death,” an officer of Chetla police station said.last_img read more

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Bank employee murdered in Domjur torso found in sack

first_imgKolkata: A bank employee was brutally murdered at Makardaha, Domjur in Howrah on Wednesday.Police recovered the beheaded body of the victim, Partha Chakraborty (27), after getting intimation from locals. His body was later identified by his family members.He worked as a cash collector at the Salap branch of a private bank.According to some colleagues of Partha, he stayed at the same building where the bank is situated. Every morning, he used to go and collect monthly installments from women of several Self-Help Groups, who were granted loan by the bank. After having collected the money, Partha used to come back to office within 1:30 pm. Also Read – Rain batters Kolkata, cripples normal lifeOn Wednesday, as Partha did not reach office by his usual time, his colleagues and seniors tried to contact him and found his phone switched off. In the meantime, some locals noticed an abandoned sack with blood dripping from it. The locals immediately informed Domjur police station. At around 2:30 pm, a police team from Domjur police station reached the spot. As the knot on the sack was untied, police were stunned to see a chopped body inside. The torso was only left. The head, hands and the lower portion from the knees were not found inside the sack. The body was sent for an autopsy. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedWhile the police were trying to identify the dead person, around 4 pm, some of Partha’s colleagues went to file a missing complaint.Hearing the missing person’s description, the police obtained his family’s phone number and informed them about the unidentified body.On Wednesday night, Partha’s family members went to Domjur police station where they were shown his undergarments and the sacred thread found from his body.The family members identified Partha from the tags on his undergarments. “When we found that Partha did not reach office on time, we tried to call him. But his phone was switched off. Then our branch manager decided to send us to the places where Partha had supposedly gone for cash collection,” said one of Partha’s colleagues.He also added: “We came to know that he visited the second last point at around 12:30 pm. We then decided to go to police for help. He had Rs 3 lakh cash with him which had also gone missing,” Police sources informed that investigators have found the number from which Partha had received the last call, after going through his call records.They found out that the number belonged to a woman, but police are yet to verify it.According to the investigators, the murder might have been committed to seek personal revenge because if the motive was to rob him, his body wouldn’t be found mutilated in this manner.About the investigation, Police Superintendent of Howrah rural Gaurav Sharma said: “Investigation is on. We are trying to find the missing partsof the body.”last_img read more

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