Hybrid energy harvester generates electricity from vibrations and sunlight

first_img More information: Dae-Yeong Lee, et al. “Hybrid energy harvester based on nanopillar solar cells and PVDF nanogenerator.” Nanotechnology 24 (2013) 175402 (6pp). DOI: 10.1088/0957-4484/24/17/175402 (a) Diagram of the silicon nanopillar solar cell. (b) Diagram of the hybrid energy harvester consisting of a piezoelectric nanogenerator integrated on to of a silicon nanopillar solar cell. Credit: Dae-Yeong Lee, et al. ©2013 IOP Publishing Ltd The researchers, Dae-Yeong Lee, et al., from Sungkyunkwan University and Samsung Advanced Institute of Technology, both in South Korea, have published their study on the hybrid energy harvester in a recent issue of Nanotechnology.”By using the hybrid energy harvester, two different energy sources can be utilized in one platform,” coauthor Hyunjin Kim at the Samsung Advanced Institute of Technology told Phys.org. “Thus the total output power from the hybrid harvester can be increased compared to each separate harvester. Furthermore, by harvesting two energy sources in one device, continuous output can be generated even when only one energy source is available.”To design the harvester, the researchers turned to silicon nanopillar solar cells for the sunlight harvesting half of the device. Previous research has shown that silicon nanopillar solar cells are promising candidates as photovoltaic devices due to their low reflection, high absorption, and potential for low-cost mass production. After fabricating the cells using a plasma etching technique and annealing processes, the researchers coated the top of each cell to prepare it for placement of the piezoelectric generator, which was stacked on top using a spin coating method. Last, top and bottom electrodes sandwich the device.The entire harvester has a height of just a few hundred nanometers, with the bulk of the height coming from the 300-nm-tall nanopillars in the solar cell. In tests, the energy harvester could generate electricity from the solar cells with a 3.29% conversion efficiency. At the same time, the harvester could generate 0.8 V of output voltage when exposed to a 100-dB sound. The hybrid device suggests that harvesting both solar and vibration energies can enable more efficient harvesting in certain environments compared to a device that harvests just one kind of energy. “This energy harvester can be very useful where there is no electric grid connected,” coauthor Won Jong Yoo at Sungkyunkwan University said. “For example, this device will be useful in moving vehicles such as moving boats, trains, automobiles, etc. The output of 0.8 V is just preliminary data. If we optimize the device structure and fabrication condition, the output power will be increased significantly.”In the future, the researchers plan to fabricate all-flexible hybrid energy harvesting devices using plastic substrates in order to harvest mechanical energy more efficiently. Citation: Hybrid energy harvester generates electricity from vibrations and sunlight (2013, April 17) retrieved 18 August 2019 from https://phys.org/news/2013-04-hybrid-energy-harvester-electricity-vibrations.html (Phys.org) —Devices that harvest energy from the environment require specific environmental conditions; for instance, solar cells and piezoelectric generators require sunlight and mechanical vibration, respectively. Since these conditions don’t exist all the time, most energy harvesters don’t generate a constant stream of electricity. In order to harvest ubiquitous energy continuously, researchers have designed and fabricated a hybrid energy harvester that integrates a solar cell and piezoelectric generator, enabling it to harvest energy from both sunlight and sound vibration simultaneously. 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.center_img Explore further Journal information: Nanotechnology Copyright 2013 Phys.org All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of Phys.org. IMEC reports 40 microwatt from micromachined piezoelectric energy harvesterlast_img read more

New idea for Dyson sphere proposed

center_img Journal information: arXiv (Phys.org)—A pair of Turkish space scientists with Bogazici University has proposed that researchers looking for the existence of Dyson spheres might be looking at the wrong objects. İbrahim Semiz and Salim Oğur have written a paper and uploaded it to the preprint server arXiv, in which they suggest that if an advanced civilization were to build a Dyson sphere, it would make the most sense to build it around a white dwarf. Citation: New idea for Dyson sphere proposed (2015, March 30) retrieved 18 August 2019 from https://phys.org/news/2015-03-idea-dyson-sphere.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

Glowing sea turtle like red and green spaceship spotted

first_img © 2015 Phys.org Dozens of fish and shark species do it; the turtle came as a surprise. These animals light up due to unique structures in their skin which enable them to biofluoresce, said Lee. The definition is given as “the ability to reflect the blue light hitting a surface and re-emit it as a different color,” such as green, red or orange.Lee wrote that “the marine biologist captured the turtle sighting on a video camera system, whose only artificial illumination was a blue light that matched the blue light of the surrounding ocean. A yellow filter on the camera allowed the scientists to pick up fluorescing organisms.”According to National Geographic, the critically endangered hawksbill sea turtle is the first reptile scientists have seen exhibiting biofluorescence. According to Mongabay, David Gruber, a marine molecular biologist at City University of New York, said he made the discovery mostly by accident while filming biofluorescent coral off the Solomon Islands coast —the glowing sea turtle swam right by him.Gruber’s encounter was recorded in a video, showing when he saw the turtle. “Scientists have only tuned in to bioflourescence in the last ten years and as soon as we started tuning into it we found it everywhere.”He compared the sight of the glowing sea turtle to “a bright red and green spaceship, underneath my camera.” The turtle was very calm and appeared to “hang” out with Gruber and team.One point about bioflourescence in general is that these creatures are using light in a way we do not see. “It’s a hidden world that we’re just now beginning to tune into,” Gruber, said in an earlier National Geographic interview.Why would the sea turtle have developed biofluorescence? It’s too early to say for sure. The sea turtle was glowing neon green and red. The discovery nonetheless turns up questions in search of answers. Why do the turtles have this feature? How are they using this feature? “We know that the sea turtle has really good vision,” commented Gruber,” and they go on long and arduous migrations.” Are they using this feature to find each other? To attract each other? Still other questions as noted in the National Geographic article which Gruber wants to explore: can these turtles see the biofluorescence; do they take in compounds from their food that let them fluoresce, or do they make their own compounds? Another noteworthy point about these sea turtles: they are critically endangered. Quoted in National Geographic, Gruber said, “It’d be fairly difficult to study this turtle because there are so few left and they’re so protected.” Their population numbers have declined by almost 90 percent in recent decades. Hawksbill sea turtles are in turn one of the rarest species on our planet, he said, and the animals remain a mystery. Explore further Credit: National Geographic video Oldest fossil sea turtle discoveredlast_img read more

Prabhu allays privatisation fear seeks private investment

first_img“The railways wants private capital for carrying out its enormous task. Getting private capital is not harmful to public nor to anybody. There should not be any misgiving about it. It is not privatisation,” he said in an informal chat with reporters here.Station development, utilisation of advertising space and commercialisation of vacant land are some of the areas which are being explored by the railways for attracting private investment, besides allowing 100 per cent FDI in the rail sector. Also Read – Need to understand why law graduate’s natural choice is not legal profession: CJIRailway unions have been raising their voice against any move towards privatisation in the railway sector.Prabhu said at present, the railways is in the need of about Rs 6 lakh crore to Rs 8 lakh crore for completion of its all ongoing projects.He said a White Paper is being prepared to be presented in Parliament which will have all details.“First, there will be a diagnosis, then solution. White Paper is the diagnosis and then we will formulate a plan as a solution to the problems,” he said  Also Read – Health remains key challenge in India’s development: KovindWhen his attention was drawn towards the claim of Rs 90,000 crore surplus made by the then Railway Minister Lalu Prasad, he said the prevailing condition in the railways is the result of the policy pursued in the past few years. “It is not because of recent happening. It is because of last 20/25 years that the railways has come to this pass,” he said, without naming anybody.“I am not blaming anybody for this. Whatever problems we will try to solve these,” he added. Emphasising on the drastic need for improvement in the railways, he said, “Improvement in customer service, safety upgradation, and modernisation of rail infrastructure is the need of the hour and these require money.”  He further said there are two sources of getting additional funds. “One is passenger fare, the other is gross budgetary support (GBS).” Prabhu, considered to be pro-reform said, “We need additional resources to improve customer service. Freight tariff is already high. Passengers will happily pay more if we improve service.”  On attracting private investment, the Railway Minister said a new model is being worked out for development of stations with private participation. “It is in the final stage and we will take it to the Cabinet for its approval before launching the model for private players.” He said there is also a remendous scope in earning more from the advertising in rail premises. “We can earn Rs 10,000 crore from advertising alone. The scope and benefit for advertisers in railways are much more than other areas as there is a larger captive audience for longer hours.”last_img read more

A satirical dig at society

first_imgIntrospective and satirical works that question a farmer’s diminishing importance in society form the crux of artist Akshay Raj Singh Rathore’s first solo show that he has titled Impotent Rage.In the exhibition of mixed media installations at Gallery Espace art gallery here, the 36-year-old visual artist who hails from a landed zamindari family of Vidisha in Madhya Pradesh turns his gaze inwards.“I grew up in an atmosphere dominated by upper caste politics and witnessed deterioration of rural social structure. Also, many other influences made me aware of forces and issues at stake within contemporary societies,” says Rathore who holds a bachelors in Applied Arts from Baroda University. Also Read – ‘Playing Jojo was emotionally exhausting’In the year 2009 the artist was part of Soil Bite, a Khoj International Artists’ Association workshop held in Patna, which explored ties between nature and humans.In the year 2010, Rathore attended the Sandarbh Residency in Partapur in Rajasthan, where his performative work asked people to leave their footprints on a disputed street being claimed by two religious communities. His work questioned land ownership and its ramifications.In his next residency in El Salavador in 2011, he witnessed a struggle over ‘fertile land’. Also Read – Leslie doing new comedy special with Netflix“This show is a culmination, in a way, of all those experiences. It is a not a single-themed show. It delves into the hidden angst in rural India, which is invisible, even impotent,” says Rathore, now based in Paris.An installation in clay titled Civil/Uncivil sequenced into three stages – the origin – a lump of raw clay; the moulding – a functional brick; and the third, the brick’s broken down form, metaphorically questions the implementation of a system that forces people into following a rigid and edgy structure, whereas the original, organic counters are lost. “It’s a debate between what is civil and uncivil. It’s textural – it’s about the earth we inhabit and how we consider poor farmers to be uncivilized though they are the ones who are reason of the land’s fertility,” says Rathore. Obituary is a portrait of farmer Tikaram, standing alone, staring at a wall of seeds from his farm.“Tikaram, a 70-year-old belongs to a group of farmers who had mastered the best technique of utilising land fertility. He still does all his farming alone and maintains an ethos of bio-diversity and organic produce on his farm. The work is a tribute to the death of this sort of wise farming,” says Rathore. Accompanying the drawing of the farmer are sets of photos of seeds taken at Tikaram’s garden and the unique metamorphosis processes, following natural rhythms.“Now there is no control of a farmer over seeds, diversity and fertility, more so with the advent of new innovative trends, genetically modified seeds and the entire concept of scientific control over life,” says the artist.Food In Hand is a series of photographs of scooping out food grains taken at various local mandis and regional haats.The collection is a visual journey through weekly markets in rural India exploring the diversity of food they offer.“With the rise in packaged food, we have lost sensation of touching, smelling and ‘feeling’ what we eat. Packaging has rendered our diversity meaningless,” says the artist.His work Impotent Range is an installation of paintings, drawings, photographs, text and found material.last_img read more

Mamata to leave for Germany Italy tour on Sept 16

first_imgKolkata: Chief Minister Mamata Banerjee will set out for her tour to Germany and Italy on September 16, to bring more investments to Bengal.Chief Minister Mamata Banerjee said: “We don’tprefer to tour abroad much, unlike some other Chief Ministers who go out of thecountry 15 to 20 times a year. Some even have their own aircraft. But we need to go abroad once a year for the sake of Bengal and to bring in more business.””We organise Bengal Global Business Summit (BGBS) every year. Representatives from around 40 countries attend the BGBS. They also request us to visit their countries. They might also not take it in a right way if we do not accept their invitation,” Banerjee said, adding that she will be holding one meeting at Frankfurt in Germany and another at Milan in Italy. Also Read – Rain batters Kolkata, cripples normal lifeShe further said that Italy is famous for its leather goods manufacturing industry. Bengal is also coming up as the number one state in the same sector in the country and now, many factories from Lucknow are shifting to Bengal.She said that there was an investment proposal of Rs 9.5 lakh crore in the BGBS and investment of Rs 3.60 lakh crore is already getting implemented.”A big team from Germany attended the BGBS and they had also invited us to visit their country,” Banerjee said, adding that there was also requests for visiting Poland. The state Power minister Sobhandeb Chattopadhyay had gone there. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedDebashis Sen, Additional Chief Secretary of the state IT and Electronics department, will be going to Silicon Valley. Banerjee, who will set out for her tour on September 16, will return to Kolkata on September 28.She further said that a group of ministers (GoM) and a committee of officers are being constituted to deal with any emergency situation and natural calamity in the state, during her visit to Frankfurt and Milan.She said: “We will always be available over phone. But the GoM will be able to tackle the situation here with proper coordination with the committee of officers, in case there is any emergency.” There are eleven ministers in the GoM, including state Education minister Partha Chatterjee, Urban Development and Municipal Affairs minister Firhad Hakim, Transport minister Suvendu Adhikari and Irrigation minister Saumen Mahapatra. Meanwhile, there are 15 senior officials of different departments in the Committee of Officers.In connection with natural calamities like flood, she said that there has been heavy rainfall in China and the water is entering Bhutan and then Alipurduar and Jalpaiguri. Similarly, water flows into the state from neighbouring states like Jharkhand as well.last_img read more

Dance fiesta

first_imgTo celebrate the occasion of World Dance Day, Ministry of Culture and the India International Centre in association with Oil India, NTPC and IndianOil, is coming up with a two-day programme in the national Capital.Beginning from April 30, the programme will be held in the main auditorium, India International Centre. Day one of the programme will have public demonstration of Bharatanatyam at a class conducted by Geeta Chandran. In the evening, there will be discussion where dancer Geeta Chandran will exchange dialogues with Padma Vibhushan Dr Yamini Krishnamurthi. It will be followed by an interactive presentation of Bharatanatyam by Dr Swarnamalya Ganesh. Also Read – ‘Playing Jojo was emotionally exhausting’Day two will have a movement workshop titled- ‘Muscle Memory’ by Dr Anita Ratnam, which will be open to all dance styles. In the evening, a tribute to Padma Bhushan (the late) Kalanidhi Narayanan, will be held where speakers/performers such as Dr Kapila Vatsyayan, Guru Jamuna Krishnan, Rasika Khanna and (Padma Shri) Pratibha Prahlad will participate. It will be followed by Bharatanatyam performance by Dr Vasudevan Iyengar and Kathak performance by Sanjukta Sinha. Also Read – Leslie doing new comedy special with NetflixFor over a decade, Geeta Chandran’s Natya Vriksha celebrates this occasion every year. Each year’s celebrations are planned differently and this year too, a heady mix awaits audiences. April 29 is International Dance Day also known as World Dance Day, it was introduced in 1982 by the International Dance Committee of the UNESCO International Theatre Institute. The date was chosen to commemorate the birthday of Jean-Georges Noverre, a French dancer and ballet master and a great reformer of dance.last_img read more

4 including mastermind held over pretext of offering US dollars

first_imgKolkata: The Detective department of Bidhannagar Police has arrested four persons in connection with the cheating case of selling dollars in front of Paribesh Bhavan near Beleghata.Sources said among the arrested persons, one was the mastermind behind the whole operation.The duo arrested earlier were given the task to identify such people who could be there target. The four identified as Iliyas Hossain, Mohammad Robiul Mir, alias Musha, Sobahan Howladar and Melon Shaikh. Also Read – Rain batters Kolkata, cripples normal lifeAll of them were arrested from Mahammadpur in Rajarahat area. All of them were remanded to 4-day police custody.According to the police, on the morning of August 30, a person named Abdul Halim, a resident of Karaya lodged a complaint with Bidhannagar South Police Station.He informed he has been duped of Rs 1 lakh. Two persons promise to sell him hundred notes of 20 US dollar.Halim said he met a person at Chittaran National Medical College hospital on August 30, who claimed that his name is Kabil. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedAt that moment, Kabil was collecting help saying he needs money for his father’s heart operation. Hearing the poverty issue, Halim gave him a hundred rupee note. Just after that, Bilal took out a 20 US dollar note and asked Halim to exchange it. Halim took the dollar and later exchanged it from Park Street. After Rs 950 was handed over to Kabil and his father near Paribesh Bhavan crossing, Kabil asked Halim that he is in dire need of Rs 1 lakh for his father’s operation.If Halim provides him with the money, then he would give him the 100 notes of 20 US dollar. On September 4, Kabil’s brother Musha and his father handed over a packet wrapped in a towel.After the money and packet got exchanged, Musha asked Halim to open the packet to verify the dollars. When Halim was unpacking it, both Musha and his father fled. On opening the packet, Halim found some folded newspapers and a dishwashing soap bar.Police informed Mir is the principal accused, who is the mastermind. Rest three were given the task to identify and approach persons who could be there possible targets.last_img read more

Water may help you curb appetite

first_imgLooking for ways to shed those extra kilos around your waistline? Worry not, according to a study, drinking water along with a meal can fill the stomach and signal the brain to stop eating.The findings showed that the brain listens to the stomach during eating. Drinking more water can alter messages from the stomach which can be interpreted as fullness by the brain. Further, intake of water along with a meal can increase stomach distension, curb appetite in the short term as well as increase the regional brain activity. This means anyone who is looking to lose weight or cut down on eating would benefit from a large drink with their meals. Also Read – ‘Playing Jojo was emotionally exhausting’For the study, the team collected data from 19 participants during two separate sessions with different consumption procedures. In the experiment, participants drank a milk-shake on an empty stomach, which was followed by a small (50 mL) or large glass of water (350 mL). The large glass of water doubled the content in the stomach compared to the small glass. Those who drank the large glass also felt less hungry and felt fuller. The real time data of the brain, the stomach, and people’s feelings of satiety was measured simultaneously during the meal.  Also Read – Leslie doing new comedy special with NetflixMagnetic Resonance Imaging (MRI) images were used to see how the different amounts of water affected stretching of the stomach– the large glass of water doubled the stomach content as compared to the small glass. “Combining these types of measurements is difficult, because MRI scanners are usually set-up to perform only one type of scan,” said lead author Guido Camps from Wageningen University in the Netherlands. “We’ve been able to very quickly switch the scanner from one functionality to another to do this type of research,” Camps added.last_img read more