Sunlight funnel collects light from all directions

first_img Explore further Journal information: Nature Communications Researchers have designed a light-harvesting funnel that absorbs sunlight from any direction and concentrates it onto smaller areas, such as high-performance solar cells. By stacking multiple funnels, each tuned to a different wavelength of light, the researchers expect that it could be possible to convert the entire solar spectrum into electricity with high efficiency. Citation: Sunlight funnel collects light from all directions (2018, March 1) retrieved 18 August 2019 from https://phys.org/news/2018-03-sunlight-funnel.html Tweaking quantum dots powers-up double-pane solar windows Randomly oriented light-harvesting pigments (green) funnel the sun’s energy to other molecules (red) that all have the same orientation, which diret the energy onto a photoconversion device. Credit: Pieper et al. Published in Nature Communicationscenter_img © 2018 Phys.org The scientists, led by Peter Jomo Walla at the University of Braunschweig in Germany, have published a paper on the light-harvesting funnels in a recent issue of Nature Communications.Although other solar concentrators exist that collect the sun’s energy from large areas and direct it onto smaller areas, these devices face certain limitations. For instance, they don’t work well in the shade, instead requiring direct solar irradiation, and as a result they usually rely on active sun-tracking systems. Nature has shown, however, that it’s not impossible to design a solar collector that overcomes these limitations. In living organisms that use photosynthesis, hundreds of randomly oriented pigments absorb photons even from indirect light, and funnel the energy toward a photosynthetic reaction center. Each step in this process occurs with nearly 100% efficiency.In the new study, the researchers modeled the new light-harvesting funnels on nature’s design. The devices consist of a large number of randomly oriented “donor” pigments that can absorb light from nearly all incident angles, and funnel it onto a smaller number of “acceptor” molecules that are all oriented in a single direction in order to direct the light onto a photoconversion device. This concept can reduce the intrinsic losses of previous solar concentrators to below 10%.”By minimizing intrinsic loss mechanisms of previous light concentrators, I believe we have found a concept and an affordable realization that can help lead to the more widespread use of precious high-performance photovoltaics,” Walla told Phys.org.In tests, the researchers demonstrated that the new solar concentrator absorbs approximately 99% of the incident light, with minimal losses due to reabsorption and reflection. The device also has a light redirection quantum efficiency of 80%, which the researchers note is the most important parameter as it depends on the particular wavelength of the photons. In the future, the researchers expect that these devices can be stacked on top of each other, with each device containing different pigments corresponding to different spectral ranges of sunlight. As the device materials are affordable, a stacked structure could lead to a low-cost, efficient method of collecting the sun’s energy from across the entire solar spectrum. “The pigments used in our proof-of-principle study currently cover only the blue spectral range and are not stable enough for long-term exposure to sunlight,” Walla said. “However, our concept allows for screening a multitude of additional stable pigments of different colors for their ability to act either as light-harvesters or light-redirectors. We are very enthusiastic about finding further suitable pigments and stacked architectures to ultimately cover the entire solar spectrum with high efficiency.” More information: Alexander Pieper et al. “Biomimetic light-harvesting funnels for re-directioning of diffuse light.” Nature Communications. DOI: 10.1038/s41467-018-03103-4 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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From supergiant to solarmass star Study finds HD 179821 less massive than

first_img Discovered about a century ago, HD 179821 (also designated IRAS 19114+0002) is a star in the constellation of Aquila, surrounded by a detached dust shell. The star is currently classified as a post-AGB supergiant of spectral type G5 Ia. However, although several spectroscopic observations of HD 179821 have been conducted, the exact distance to this star remains a subject of debate. Some studies suggest that it is located about 19,500 light years from the Earth, while others cite a much closer distance of some 12,700 light years. Discrepancy in the distance estimates leaves uncertainties regarding the star’s mass and evolutionary status.Gaia’s second data release, known as Data Release 2 (DR2), has the potential to resolve such uncertainties as it offers high-precision positions, parallaxes and proper motions for more than 1.3 billion sources in the sky. A team of astronomers led by Mudumba Parthasarathy of the Indian Institute of Astrophysics in Bangalore used DR2 data to obtain the parallax of HD 179821, which allowed them to make new distance calculations.The parallax of HD 179821 was found to be approximately 0.31 mas. Employing an inference procedure developed by other researchers in 2018, Parthasarathy’s team calculated that this value corresponds to a distance of about 9,600 light years. Gaia parallax also allowed them to find that the star is located some 850 light years below the Galactic plane.Furthermore, the derived distance and other parameters provided by previous studies, such as spectral type and observed V magnitude, were essential to find the absolute magnitude and bolometric luminosity of HD 179821. These values were estimated to be –5.7 and 4.3 respectively.According to the paper, the derived properties exclude the possibility that HD 179821 is a supergiant star with a mass between 19 and 30 solar masses, which was suggested by observations conducted in recent years.”The derived MV = -5.7 clearly establishes that HD 179821 is not a 30 or 19 Msun post-red supergiant. (…) The bolometric magnitude clearly excludes the possibility, defended by many authors, that it is a very massive (30 to 19 Msun) post-red supergiant star,” the astronomers underlined.They concluded that HD 179821 is a post-AGB star of mass in the range of about 0.8 solar masses, an effective temperature of 5,660 K, and a radial velocity of approximately 81.8 km/s. When it comes to the evolutionary status of HD 179821, the astronomers noted that it resulted from an intermediate mass AGB star or from a star that is at the lower limit of a super-AGB star. Its progenitor most likely had an initial main sequence mass of about four solar masses. Citation: From supergiant to solar-mass star: Study finds HD 179821 less massive than previously thought (2019, February 8) retrieved 18 August 2019 from https://phys.org/news/2019-02-supergiant-solar-mass-star-hd-massive.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. HD 179821. Credit: Hubble Legacy Archive © 2019 Science X Network Explore further Caffau’s star is a dwarf, Gaia DR2 confirms More information: M. Parthasarathy. The puzzling high velocity G5 supergiant star HD 179821: new insight from Gaia DR2 dataarxiv.org/ftp/arxiv/papers/1901/1901.08995.pdf A post-asymptotic giant branch (post-AGB) star known as HD 179821 turns out to be significantly less massive than previously thought, according to a new study. Using new data from ESA’s Gaia satellite, astronomers found that HD 179821 is not a supergiant, which was suggested by previous observations, but is rather a solar-mass star. The finding is presented in a paper published January 28 on arXiv.org.last_img read more

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Beacon of hope

first_imgSashaying the ramp with panache, a special group of women will walk up the stage for a cause. The cause is to create breast cancer awareness by imparting knowledge about the disease. The second festival of hope – The Pink Blue Ribbon Fest comes in the wake of the rise in number of breast cancer amongst the young Indian women on 10 May. Keeping this concern up on its agenda, the Indian Cancer Society and DLF joined hands to declare 2013 as the year of breast cancer awareness. The idea is to make women respect and be conscious of their own bodies to curb the disease in its primary stages. Also Read – ‘Playing Jojo was emotionally exhausting’In tune with the theme, the models for this festival are no ordinary women. For this noble endeavour, the festival will showcase fashion from select designers on models who are all breast cancer reconstruction patients. It also applauds the men in their lives who go out of their way to support the women they love through thick and thin.The festival comes close on heels, post the last festival of hope held on 1 and 2 December, 2012. While the last show was a success with the who’s who of Delhi walking up the ramp for the 20 new age designers, this time around the designers on board for the event include Ramonn Lamba, Pam Mehta, Gopa Kumar and many more. Adding a dash of bollywood to the fest, it will feature singer Anamika and renowned Bollywood artist Swaroop Sampat. Also Read – Leslie doing new comedy special with NetflixAnamika will pay a tribute to Nazia Hassan, who lost her life to cancer, by singing her song Boom Boom.Promoting awareness about different types of cancer, the event shall be a mix of fashion, culture and above all, a cause. The festival is wrapped in a cultural fiesta to appeal to the masses and make them vigilant about the disease.Though not every woman needs a reconstruction or is even interested in it, but she definitely needs to know the necessary information associated with it. The goal of the festival is to reach out and significantly increase the number of patients who never get a consultation about reconstruction after going through the physical and emotional trauma of the cancer treatment. It may not be a glam show, with the overpowering glitz of Bollywood and the newest trends in fashion, but the overriding theme of awareness takes it a notch up, compared to any other fashion week.Come and a be a part of the celebration of the ones who fought, challenged and survived breast cancer.last_img read more

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Theres no set pattern for perfect sex

first_imgI’m a divorced female and I fail to understand why frustrated men always propose sex! Does being single mean available these days?Name withheld, MuradabadIdeally it shouldn’t be but most of the times ‘ideal’ situations don’t arise often enough. The society and its various animals act and react in a manner that shows their true nature. Be firm in your belief and don’t let these winds break you down. Let go of yourself and have fun their way only when you are ready. Be single and be happy in your world. Ignorance is bliss and use this till you don’t find the ‘right’ one. Also Read – ‘Playing Jojo was emotionally exhausting’I don’t like it when my husband is friendly or is flirting with any other woman. I’m not jealous but I get very uncomfortable. How can I change him?Mrs. Patil, New DelhiIt isn’t possible to change anyone! Too much pressure will turn him sly and he might continue his traits behind your back. I suggest you to let go of the feelings that you are going through and trust your partner. Don’t restrict his movements but time and again exhibit your emotions. Don’t be pushy, but warm. Don’t react always. Space and trust will make situations healthy and peaceful. Don’t try to change anyone, it doesn’t work! Also Read – Leslie doing new comedy special with NetflixMy mother still treats me like a little boy! She pampers me in public and embarrasses me in front of my friends! I’m 17 and it feels horrible.Rajat, FaridabadMake her sit down and explain to her what irritates you. If need be, route it through your father. Sometimes parents always think that we are children and treat us just like they used to when were actually kids. It is her love that she showers. Don’t be rude but act mature to handle this. You are atleast lucky to have loving parents. There are many who are deprived of this. I’m getting married in January next year. I’m sleepless about my sex life. I’m virgin and have never been close to any man before.Name withheld, AgraLife will be beautiful, dear. Marriage is a joyride if both partners love and respect one another. There is enough material on the internet and great books available to educate you on sex. Don’t panic and be transparent with your partner. He will surely understand your fear and take it slow. Try and erase all fears and have a beautiful life ahead!Is it true that younger men satisfy older women better? Just curious.George, NoidaThere is a tendency amongst younger men to get attracted to older women or older men with younger woman. Young men sure have the physical capacity to satisfy a woman and some woman love to be loved by younger ones. But sex is a spontaneous act and there is no such rule of an ideal age. The chemistry between partners is most important and I personally think, there’s no set formula for perfect sex.Have a love or life query you cannot find an answer to? Send your questions to – roopshashotm@gmail.comlast_img read more

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A blend of art and coffee

first_imgThe Home of the Traveller, India’s first global home décor in association with the Embassy of Italy  hosted an exclusive art exhibition by Simona Bocchi, Italian artist and a contemporary sculptor, at their flagship store.The exhibition showcased Bocchi’s works in wide range of materials including carrara marble, bronze and jute. Originally from Monza Italy, Simona Bocchi is a specialist in contemporary sculpture; she has made Udaipur her home for the past four years working with numerous local and national level craftsmen specializing in marble carving and inlay work learning from their techniques whilst teaching new methods of sculpting. Also Read – ‘Playing Jojo was emotionally exhausting’Commenting on her exhibition, Bocchi said, ‘ I have exhibited all my fresh pieces here and I have recently started working with jute. I have also used cow dung to create some of my pieces, I feel more connected to the traditional India by using of these materials which are also environment friendly. India has inspired my art and the evolution of the ancient culture motivates my inner exploration.’The fine spring evening also saw the home décor boutique conducting tasting session of the unique blends of Italian Nero Coffee that traces its origin to the beginning of coffee culture in Italy in the 16th century when a famous merchant of Venice called Cesare Duni started to study coffee, out of curiosity about its healing properties. Also Read – Leslie doing new comedy special with NetflixThe use of unique bases lends a groovy flavour to this coffee with an elegant density and an extraordinary stability.Speaking on the occasion, director of The Home of The Traveler, JJ Valaya said, ‘The more we travelled and found ourselves inspired by culture, art and architecture belonging to different parts of the world, the stronger grew our desire to bring the most exquisite offerings to your doorsteps in one cohesive space. Housed within the flagship store is MORE@THT, a space dedicated to showcasing outstanding talent and unique craftsmanship. More is an acronym for Moving, Original, Resourceful & Experimental, all being virtues found in our special exhibitions and shows.’last_img read more

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SEC under threat by TMC Sinha

first_imgKolkata: BJP national secretary Rahul Sinha today alleged that the State Election Commissioner (SEC) has been subjected to threats by the ruling party on panchayat polls and said he should inform the court about it in a private statement. The SEC A K Singh had even told a BJP delegation that his mobile phone “is tapped and the land line calls are recorded,” Sinha told a press conference here.”The announcement of a one-phase panchayat poll on May 14 has been made under threat and intimidation by the ruling Trinamool Congress leaders and ministers. The SEC should apprise the court of the situation in a private statement to clear the air,” Sinha said. Also Read – Heavy rain hits traffic, flightsDemanding the May-14 panchayat poll date be scrapped, Sinha said the panchayat polls should be conducted by the SEC under the supervision of the High Court.”The entire state is looking at the High Court. The Panchayat Minister Subrata Mukherjee had said it was the duty of the SEC to ensure security during the panchayat elections.But who will ensure the security of the SEC who is under serious threat”, the former party president of West Bengal unit said. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedHe alleged that democracy was being throttled in West Bengal by the TMC which had prevented the opposition to file nomination papers in over 20,000 seats or 34 per cent of total seats in panchayats.He said till May 4, seven BJP functionaries had been killed in panchayat-related clashes, 412 party workers hospitalised and 38 functionaries missing.On deployment of central forces in the state, Sinha said even if the forces were requisitioned they would be confined to camps and not be deployed. For this reason “we call for holding of panchayat poll under the supervision of the judiciary.” To a question on demand for imposition of Central rule in state, Sinha said “we don’t want imposition of President’s Rule which will give ammunition to a discredited Trinamool Congress which is already on its way out.”He said “BJP will be gainer in a one-day poll as TMC won’t be able to carry musclemen from one part to another on a single date, but the need of the hour is to uphold the spirit of democracy.”last_img read more

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Ramayana revisited

first_imgThe fascinating story of the Ramayana is regaling a vastly different audience in a country far away from its native India, as National Gallery of Australia (NGA) in Canberra opened an exhibition of vintage miniature paintings that strings together a grand narrative of the ancient epic.Titled, The story of Rama: Indian Miniatures from the National Museum, New Delhi, the three-month show features 101 paintings created between the 17th and 19th centuries, and is the first major initiative under a recently-inked pact on culture between India and Australia. Also Read – ‘Playing Jojo was emotionally exhausting’NGA Director Gerard Vaughan said that the exhibition of ‘vibrant and exquisite Indian miniature paintings is important’ for the gallery. “It forms part of our commitment to share the art and rich cultural heritage of India with all Australians,” he added, speaking about the finely-detailed paintings featuring a rich diversity of regional styles. Selected from the collection of National Museum (NM) of over 17,000 miniatures, the largest in the world, the NGA exhibition is open till August 23, and the entry is free for the public. Also Read – Leslie doing new comedy special with NetflixNM Director-General Sanjiv Mittal, who was present at the function, expressed delight on behalf of his country, upon sharing with the Australians, the story of Ramayana.NM curator Vijay Kumar Mathur, who has selected the 101 paintings in a chronological progression capturing the story of the Ramayana, revealed that the collection had been pooled in from India’s northern, central and eastern territories. “These miniatures represent art from various schools of Mughal, Deccan, Pahari, Rajasthan and Central India. They stand for a matured movement that colourfully visualises the spirit of the Ramayana,” he expressed.last_img read more

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Think Mughlai and you are spoilt for choice

first_imgThough you’ll find versions of the same in other Mughlai outlets, Anadi Cabin deserves mention as perhaps the best Mughlai paratha outlet in town. Their Kabiraji cutlet is also scrumptious, to say the least. While the double egg Mughlai paratha comes for Rs 62, the Kabiraji cutlet costs Rs 80 while a plateful of yummy mutton kasha costs Rs 220. Pair the yummy mutton kasha with parathas. The place can accommodate about 30 people though the ambience is not that great but foodies swear by the Mughlai and the kasha mangsho they still serve.  Also Read – ‘Playing Jojo was emotionally exhausting’Set up in the 1940s, the mutton rezala and slightly sweet parathas are to die for at Sabir’s, the vintage Mughlai outlet. Founded by Sabir Ali from Lucknow, this restaurant has been a favourite of the Mahanayak Uttam Kumar and the legendary film director, Satyajit Ray.  The story goes that Sabir Ali travelled all the way from Lucknow to Kolkata—in search of a living. He came to Kolkata in 1940 and started off as a helper in a small hotel. In 1948, he opened his restaurant at 75, Princep Street. An excellent chef himself, Ali gave the restaurant an identity. There is the famous, mouth watering rezala and paratha and a sip of their special tea is enough to leave you thrilled.  Also Read – Leslie doing new comedy special with NetflixThe rezala is made with mutton breast and the ingredients used are curd, ghee, poppy seeds (posto), saffron and mace. “The proportionate mixing of the spices gives it the right taste. You will never get the taste unless you cook it in charcoal fire,” says a spokesperson. Have the mutton delicacy with their paratha. Nothing matches the duo—rezala and paratha. One can also opt for biryani along with the regular mutton or chicken delicacies. Choose from mutton kasha, bharta, chap, kebab, Kasmiri kebab. During Ramzan, their haleem and seviyaan, are in great demand.  Most of the customers are Bengalis.  Golbaari is a 109-year-old outlet in North Kolkata (Shyambazar) with a reputation for the kosha mangsho and paratha.   The gravy is finger-licking delicious but rich, albeit a little oily. Light on the pocket and savoury on the palate, one can also try their chicken cutlet, fish cutlet and mutton keema with paratha. The restaurant is not very spacious, so most of customers get their food packed. One should visit the The Great Kebab theatre at Astor’s flagship restaurant this month. Kebab-e-Que is offering an assortment of mouth watering kebabs where food lovers will be served ten variants of both vegetarian and non-vegetarian kebabs every weekend, followed by a main course meal. The treat costs an affordable Rs 749 plus taxes for two people. The kebab menu includes the Makhmali Raunake Kadak seekh Kebab or crunchy chicken seekh kebab; Hara masala tawa machli or succulent  fish marinated in special green marination and  grilled;  Tandoori murgh Pankdi kebab or drumstick of chicken marinated grounded spices cooked to perfection; mutton Shikampuri—a household recipe from Lucknow, wherein mutton mince and lentil is cooked and shallow fried while keeping the creamy centre and Lemon grass mahi tikka or  fish chunks infused with lemongrass combination of spices.The vegetarian platter includes Bhutte ke kebab or fresh baby corn and American corn with home ground spices; Dahi ke kebab or mouth-melting kebab made with hung curd and the flavour of saffron and Subj soya ki seekh or combination of soya chunk  mince and melange of vegetables. Seekh kebab is served with pudina chutney. Tandoori babri aloo or baby potato is made with spicy aromatic marination; Astor tulsi paneer tikka is made by marinating delicate cubes of creamy cottage cheese with garden fresh basil, cheese and finished in a clay oven. All kebabs are served with Kachumber Salad, vinegar onion, dahi chutney— a chutney made with yoghurt, green chilly and pudina and boondi raita. The main course includes a variety of options, followed by Indian sweets and ice cream.last_img read more

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689 endangered softshell turtles recovered

first_imgKolkata: The state Criminal Investigation Department (CID) has recovered 689 endangered turtles from an Express train and detained four persons.According to the CID, sleuths got a tip-off recently about a smuggling activity of the turtles in the state. Based on information, sleuths were able to obtain valuable information and managed to get hold of the smugglers’ identities. They came to know that the turtles would be brought from Varanasi. On Tuesday, sleuths from CID’s Durgapur division boarded Doon Express and identified the smugglers. Immediately, they were surrounded by the police. While conducting searches, the CID officers recovered 689 soft -shell river turtles from inside a sack. Immediately, the four accused persons — identified as Lachman Kumar, Raj Kumar, Sushil Kumar, Raju Kumar of Sultanpur, Uttar Pradesh, were detained and forced to get off the train. Later, the accused persons stated that they were going to dispose of those turtles at Bandel Station. The accused persons and the turtles were handed over to the Range Officer of the Forest Department for further action.last_img read more

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Dy Mayor to spearhead antidengue drive

first_imgKolkata: Deputy Mayor Atin Ghosh will lead the drives against dengue that will be launched on 21 February.Ghosh said the teams of Kolkata Municipal Corporation will first visit the houses of patients who had been afflicted with dengue in 2018. “We will inspect the house and its surroundings. We have prepared a list of 47 areas of which 20 are highly vulnerable and 20 are vulnerable. Not only the KMC staffs but also private agencies and NGOs are welcome to join our drives. To make dengue drives a success there should be cooperation between the civic staffs and common people,” Ghosh said. Also Read – Bose & Gandhi: More similar than apart, says Sugata BoseThe KMC will carry out the drives in three phases. The first phase will start from February 21 and will continue till June. The second phase will start in July and continue till October while the third phase which will be a follow up phase will start in November and continue till December. Continuous drives against dengue have helped the KMC to bring down the number of cases in 2018 to one third. It may be mentioned that KMC is successful in eradicating malignant malaria which had taken the form of an epidemic in the early 1990s by identifying the areas and then conducting the drives regularly. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataThe KMC team that is engaged in conducting drives comprise of health, building and solid waste management department officials and staffs. Ghosh said councilors would be invited to join the drives along with the Borough Committee chairman. The KMC had launched a massive campaign to create awareness against Dengue on February 2 when 144 rallies had been taken out all over the city. The central rally was taken out from the KMC headquarters and it was led by the Mayor Firhad Hakim. Through the rallies the civic authorities sought cooperation of the people. Ghosh said the campaign and rallies have proved to be very effective and KMC is going to follow this method. The KMC has 16 dengue testing laboratories where blood samples are tested free of cost.last_img read more

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