Photon funnel could direct and regulate light into solar cells

first_img Journal information: Journal of the American Chemical Society It has often been said that solar cells are like artificial versions of the photosynthetic apparatuses found in plants, such as leaves, since both harvest sunlight. But nature’s leaves can do something that most solar cells cannot do: protect themselves against photochemical damage from overexposure to sunlight. Illustration of the light-harvesting funnel array that directs energy to a focal point along diverse routes, and then slowly off-loads the energy to a solar cell or other device. Credit: Raymond Ziessel, et al. ©2013 American Chemical Society More information: Raymond Ziessel, et al. “An Artificial Light-Harvesting Array Constructed from Multiple Bodipy Dyes.” Journal of the American Chemical Society. DOI: 10.1021/ja4049306 Researchers recreate photosynthesis to power devices © 2013 All rights reserved.center_img Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Photon funnel could direct and regulate light into solar cells (2013, July 26) retrieved 18 August 2019 from In an attempt to protect artificial light-harvesting devices from sun damage, chemists have designed a funnel-shaped molecular-scale array that harvests photons, spreads the energy around the array, and off-loads the energy at a relatively slow rate to a solar cell or other device. By regulating the amount of energy that enters the solar cell, the new array could extend the lifetime of the solar cell, which must function in harsh conditions associated with prolonged exposure to sunlight.The researchers, Raymond Ziessel, Gilles Ulrich, and Alexandre Haefele at the University of Strasbourg in France, along with Anthony Harriman at Newcastle University in the UK, have published their paper on their artificial light-harvesting array in a recent issue of the Journal of the American Chemical Society.”UV light is harmful to the cells and to the supporting structure,” Harriman told “Photons are lost by way of annihilation, and optimal performance requires a steady flux of photons. This is even more important for water-splitting devices, which is where we see our light harvester having real applications.”The new array consists of 21 Bodipy (“boron-dipyrromethene”) dyes, which are highly fluorescent dyes known for their good light absorption and emission. The Bodipy dyes are arranged in a funnel-like design that converges onto a focal point. When exposed to light, the array guides the excitation energy from incident photons through the funnel through a series of cascading energy transfer steps until the energy reaches the focal point. The most important feature of the design is its ability to self-regulate its energy. When the focal point is in an excited state, further energy transfer to the focal point is restricted. In order to increase the amount of energy that reaches the focal point, the topology of the array provides diverse travel routes for the energy to ensure different arrival times. The strategy involves redistributing excess energy within the array until the focal point is no longer “saturated.” This mechanism for protecting against overexposure to sunlight is not strictly based on the mechanisms used by plants. In nature, various different mechanisms have evolved for this purpose, although the details of these mechanisms are still under active debate.While the properties of the new array are intriguing, the scientists add that the actual synthesis is also state-of-the-art. Using Bodipy dyes as building blocks allows certainty about the emergent structure, unlike when using other molecules, such as dendrimers, where it is difficult to assure complete growth with each layer. In the future, the molecular-scale funnel could protect solar cells by functioning as a sensitizer; that is, transferring energy in a controlled way to the solar cells or other external devices. The array also provides a benefit in stability compared with using a mixture of compounds. And although the array restricts energy transfer, it does not decrease solar cell efficiency.”At present, the limiting efficiency is coupling together the two systems,” Harriman said. “In principle, there should be no decrease in efficiency. The real advantage will come from using a large-area collector and a small-area solar cell.”In the future, the researchers plan to improve the transfer of photons from the array to the solar cell.”We are trying to build systems where the photons move easily from cluster to cluster before being trapped by the solar cell,” Harriman said. “Also, we are looking into ways to push the photons towards the solar cell, rather than rely on random migrations. This kind of quantum coherence might be important in certain cases in nature but is way beyond the current capability of artificial systems. We have ideas on how to improve and we foresee rapid progress in this field.”last_img read more

Survey of multiple species suggests mothers preference for cradling baby on left

first_imgCredit: CC0 Public Domain (—A team of researchers with members from Russia, the U.S. and Australia has found evidence that supports the theory that left-side support of babies by their mothers is tied to brain hemispherical functions. In their paper published in the journal Nature Ecology & Evolution, the researchers describe their study of multiple mammal species and how their discovery bolsters a common theory of mother/offspring bonding behavior. 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. Explore further Citation: Survey of multiple species suggests mother’s preference for cradling baby on left tied to bonding (2017, January 10) retrieved 18 August 2019 from Study finds pregnant women show increased activity in right side of brain Many people may not have noticed, but mothers have a very strong tendency to support their babies on their left sides, especially when cradling them. Scientists have debated the reason for this with some suggesting that it allows the babies to hear the mother’s heart beat better. Others have suggested that it is due to differences in function in the two brain hemispheres. The left side is believed to be primarily concerned with processing language and making calculations, while the right side is more involved with processing emotions, recognizing faces, spatial awareness and music. The two hemispheres are also responsible for muscle control, of course, but it gets reversed in the processing—the right side of the brain controls the left side of the body while the left side of the brain controls movement of the right side of the body. A mother cradling her baby on the left, the theory goes, allows for both parties to engage more with their right hemispheres, which results in stronger bond building.To test this theory, the researchers conducted a survey of mothers and their offspring regarding left/right tendencies in multiple mammal species including oxen, reindeer, antelope, horses, walruses, sheep, three species of whales and two species of kangaroo. In so doing, they discovered that all of those surveyed had a similar preference for cradling on the left. They also found that during normal activities, offspring tended to hang around on the left side of their mothers—during times of crisis, however, offspring were moved to the other side, presumably to allow the mother to better offer physical protection.These findings, the researchers suggest, bolster the proposition that left/right preferences between mothers and offspring is based on brain hemispherical function. More information: Karina Karenina et al. Lateralization of mother–infant interactions in a diverse range of mammal species, Nature Ecology & Evolution (2017). DOI: 10.1038/s41559-016-0030AbstractLeft-cradling bias is a distinctive feature of maternal behaviour in humans and great apes, but its evolutionary origin remains unknown. In 11 species of marine and terrestrial mammal, we demonstrate consistent patterns of lateralization in mother–infant interactions, indicating right hemisphere dominance for social processing. In providing clear evidence that lateralized positioning is beneficial in mother–infant interactions, our results illustrate a significant impact of lateralization on individual fitness. © 2017 Phys.orglast_img read more

Physicists extend quantum machine learning to infinite dimensions

first_img How quantum effects could improve artificial intelligence Physicists have developed a quantum machine learning algorithm that can handle infinite dimensions—that is, it works with continuous variables (which have an infinite number of possible values on a closed interval) instead of the typically used discrete variables (which have only a finite number of values). More information: Hoi-Kwan Lau, Raphael Pooser, George Siopsis, and Christian Weedbrook. “Quantum Machine Learning over Infinite Dimensions.” Physical Review Letters. DOI: 10.1103/PhysRevLett.118.080501Also at arXiv:1603.06222 [quant-ph] The researchers, Hoi-Kwan Lau et al., have published a paper on generalizing quantum machine learning to infinite dimensions in a recent issue of Physical Review Letters.As the physicists explain, quantum machine learning is a new subfield within the field of quantum information that combines the speed of quantum computing with the ability to learn and adapt, as offered by machine learning. One of the biggest advantages of having a quantum machine learning algorithm for continuous variables is that it can theoretically operate much faster than classical algorithms. Since many science and engineering models involve continuous variables, applying quantum machine learning to these problems could potentially have far-reaching applications.”Our work demonstrates the ability to take advantage of photonics to perform machine learning tasks on a quantum computer that could far exceed the speed of any conventional computer,” coauthor George Siopsis at the University of Tennessee told “Quantum machine learning also offers potential advantages such as lower energy requirements owing to the ability to store more information per qubit, and a very low cost per qubit compared to other technologies.”Most quantum machine learning algorithms developed so far work only with problems involving discrete variables. Applying quantum machine learning to continuous-variable problems requires a very different approach.To do this, the physicists had to develop a new set of tools that work with continuous variables. This involves replacing the logic gates that are used for discrete-variable states with physical gates, which work for continuous-variable states. Building up from these basic building blocks of the algorithm, the scientists then developed new methods that power the quantum machine learning problems, called subroutines, which are represented by matrices and vectors.Although the results of the study are purely theoretical, the physicists expect that the new algorithm for continuous variables could be experimentally implemented using currently available technology. The implementation could be done in several ways, such as by using optical systems, spin systems, or trapped atoms. Regardless of the type of system, the implementation would be challenging. For example, an optical implementation that the scientists outlined here would require some of the latest technologies, such as “cat states” (a superposition of the “0” and “1” states) and high rates of squeezing (to reduce quantum noise). In the future, the scientists hope to further investigate how continuous-variable quantum machine learning can be extended to replicate some of the latest results involving discrete variables. Another interesting avenue to pursue is a hybrid approach, which would combine the methods of both discrete and continuous variables in a single algorithm. © 2017 Explore furthercenter_img Citation: Physicists extend quantum machine learning to infinite dimensions (2017, March 6) retrieved 18 August 2019 from The proposed optical set-up that could be used to implement the new quantum machine learning algorithm over infinite dimensions. Credit: Lau et al. ©2017 American Physical Society Journal information: Physical Review Letters 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

Radio galaxy 3C 236 investigated with LOFAR

first_img Warped diffusive radio halo detected around the galaxy NGC 4565 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. Using the LOw Frequency ARray (LOFAR) astronomers took a closer look at the giant radio galaxy 3C 236. The observations, detailed in a paper published July 22 on the arXiv pre-print repository, shed more light on the morphology and structure of 3C 236, which could be helpful in advancing our knowledge about radio galaxies in general. © 2019 Science X Network Citation: Radio galaxy 3C 236 investigated with LOFAR (2019, July 29) retrieved 18 August 2019 from Radio galaxies emit huge amounts of radio waves from their central cores. Black holes at the centers of these galaxies accrete gas and dust, generating high-energy jets visible in radio wavelengths, which accelerate electrically charged particles to high velocities.Giant radio galaxies (GRGs) are distinguished by radio-emitting regions like jets or lobes extending over projected distances of at least 3 million light years. With radio lobes reaching about 14.7 million light years, 3C 236 is one of the largest GRGs known to date. Although many studies of 3C 236 have been conducted since its discovery in late 1950s, still many questions about radio emission from this source remain unanswered.Instruments like LOFAR could be crucial for resolving such uncertainties. This array allows studies of extended GRG morphology in a comprehensive manner at very low frequencies. As a result, such observations could disclose details regarding energetics and activity history of radio sources.In October 2018, a team of astronomers led by Alexandar Shulevski of University of Amsterdam, the Netherlands, decided to employ LOFAR to investigate 3C 236. The main aim of these observations was to perform high-resolution mapping of the radio morphology of the galaxy’s extended structure at the lowest frequencies to date. By doing this, they hoped to trace the oldest emission regions in 3C 236.”We have examined the giant radio galaxy 3C 236 using LOFAR at 143 MHz down to an angular resolution of 7”, in combination with observations at higher frequencies. We have used the low frequency data to derive spectral index maps with the highest resolution yet at these low frequencies,” the astronomers wrote in the paper.The new observations identified an inner hotspot in the northwest lobe of 3C 236. Its presence was, in fact, detected by previous studies. However, this hotspot was found to be separated from its more diffuse outer region and has experienced more recent particle acceleration. This, according to the researchers, may indicate a short interruption of the accretion episode.Moreover, the study found that other region—the southeast lobe double hotspot—turned to be a triple hotspot. The observations have shown that hotspot’s brighter component actually consists of two components, making it three overall.In concluding remarks, the astronomers reveal what could be responsible for the observed morphology of the lobes in 3C 236. They assume that the confinement by the intergalactic medium (IGM) is the most plausible scenario.”The source energy/pressure balance with the IGM suggests that confinement by the IGM may be responsible for the morphology of the lobes; the NW lobe is probably confined and the SE one has expanded in a lower density medium, reflected in the somewhat steeper spectrum of its outer region/northern edge,” the authors of the paper wrote.They added that their research is a great example proving the usefulness of LOFAR in studying GRGs and other radio sources. The instrument has the potential to unveil previously unknown features even in objects that have been studied for decades, as was in the case with 3C 236. Explore further More information: LOFAR first look at the giant radio galaxy 3C 236, arXiv:1907.09060. LOFAR intensity map (linear scale, level limits at 1 and 150 mJy beam−1) of 3C 236 at 143.6 MHz. Image credit: Shulevski et al., 2019.last_img read more

Nurturing needs Basic and beyond

first_imgA powerpoint slide reads: My name is Vijendar Kumar Jain. I am 77 and I live in Ayudham society. Vijendar, sitting alongside his peers -both young and older one’s-practices his typing skills: the one’s he had learnt years ago which were fading out with the passage of time. Ayudham, a society for old, infirm and underprivileged children got a headway into the technologically savvy world with its newly formed computer training centre. Extending its corporate social responsibility, Airport Authority of India recently contributed 20 computers to the training centre at Ayudham Society. Inaugurating the facility, V P Agrawal, the chairman of AAI said that the computer training centre is designed to facilitate basic computer skills for the children and assist the children from nearby underprivileged communities in practicing and doing homework as per the course curriculum of their school. The centre will also have the facility for accessing web based information for elderly inmates of the home. Also Read – ‘Playing Jojo was emotionally exhausting’The society, which is a home for elderly and children, is situated on the peripheries of Delhi in Najafgarh. It is a unique concept that creates a community experience for the young and elderly inhabiting it. Above all it caters to the psychological vaccuum of their lives by offering a community lifestyle. The older inmates, belonging to the weaker sections of society are given a concession here, while the underprivileged children follow a disciplined lifestyle with a free of cost admission.  VK Jain, an aged inmate revels in the peace of mind he finds here. Considering its location in a pollution free area away from the clasps of Delhi, Ayudham is a bliss for its residents. The society even featured in the Amir Khan’s  show Also Read – Leslie doing new comedy special with NetflixSatyamev Jayate, says the caretaker, Pramod Kumar. Perhaps that also amplified its popularity as if finds guest members writing in and coming from international destinations after watching that episode.In the inaugural speech, AAI’s chairman emphasised the need for participation of senior citizen living in the NGO to come forward and help the children learn real life skills. In that way, the new computer training centre is a befitting platform for the interaction between the young and old in the society.last_img read more

6 Easy Tips to cure your skin dryness

first_imgPeople often complain of skin dryness and opt for varied beauty products to cure it. Avoiding long, hot shower bath or drinking at least two litres of water can help you rid the problem. shares tips to take care of dry skin.Avoid long, hot shower bath – True, that hot water bath relieves stress but it can also make your skin dry. Hot water reduces natural oils from body much faster than lukewarm or cold water.Use a gentle cleanser or shower gel with moisturiser – Cleanser or nice shower gels make skin smoother and removes dryness. Also Read – ‘Playing Jojo was emotionally exhausting’Use good moisturiser – If face is moisturisd properly using a good moisturiser, it helps make skin soft and smooth. Moisturisers lock in moisture and help reduce dryness.Drink plenty of water – Experts recommended to drink two litres of water every day. Drinking plenty of water will ensure your body can produce  the minerals it needs to function properly. Eat healthy – Food items or ingredients like fish (salmon and sardines), flax and walnuts help maintain body’s natural oils. Eat food items, which contain Omega-3 acids that produce natural oil and minerals to keep your body healthy. Exfoliate – Dry skin can produce dead skin cells so it is important to exfoliate weekly to get rid of these cells so your body can produce new ones.last_img read more

No more monsoon woes

first_imgRaindrops are lovely to look at, but stepping out when it’s pouring may not be the best idea for your hair. Rainwater may spoil your locks and make them look rough and greasy. But fret not!Beauty experts Ishika Taneja and Blossom Kochchar suggest use of good serums and conditioners to keep your hair nourished and hydrated during monsoon. Always use a hair protective styling mousse before styling your hair, says Taneja.‘It will protect your mane from excess heat from the dryers, straighteners and curling tong. One can also use an anti-humidity fine spray as it helps fix and keep your hairstyle in place for long hours. Use shine spray in the end as it provides additional sheen to your hair,’ she added. Also Read – ‘Playing Jojo was emotionally exhausting’Kochchar says homemade hair care remedies can be handy too. Sharing some, she said:-Add two tablespoons of curd (or more depending on your hair length) to gram flour (besan). Add little olive oil. Apply it to your hair and leave it for 15 to 20 minutes. Wash it later.-You can also use mixture of water and vinegar as an after-shampoo serum to help calm your hair down.-Prepare a mixture of one banana and one tablespoon honey. Put in your hair for 15 minutes and then wash it off. It helps make hair soft and smooth.last_img read more

Rotten meat will raise awareness of risk of animal food FIAPO

first_imgKolkata: The Federation of Indian Animal Protection Organisations (FIAPO) today said the carcass meat recovery from dumping grounds in West Bengal would hopefully raise awareness on the health risks of consuming animal products. “With the extraordinary increase in lifestyle diseases, from kidney disease to heart disease, may be it is time we re-look at our diet…to move towards a greener diet over one including animal products,” FIAPO director Varda Mehrotra said in a statement here. Also Read – Heavy rain hits traffic, flightsStating that it has information that meat consumption in the city is going down, Mehrotra said that many people were avoiding it after reports that meat was coming from dead animals of dumping grounds.”Meat being sourced from rotten bodies of cats, dogs and even diseased animals in unhygienic conditions is not uncommon. Animals bred for the purpose of meat are routinely given anti-biotics, growth hormones and other drugs and their meat may contain these drugs with many viruses and bacteria. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killed”Hopefully this situation can bring awareness… the FIAPO director said.He said many people could not make the difference between the meat of carcass of dumping grounds and slaughtered animals as they were used to consume the final product with little or no consideration to where it was sourced.Mehrotra said research showed that multiple lifestyle diseases were routinely caused or heightened by consumption of meat, milk and eggs.The FIAPO referred to cardiovascular diseases where ‘elevated level of LDL cholesterol’ (commonly called bad cholesterol) is the major reason for development of vascular (cardiovascular and cerebrovascular) diseases. “To reduce the LDL cholesterol, we need to avoid trans fats, saturated fats and dietary cholesterol. The main sources of these three foods are meat, eggs, dairy, fish and seafood,” he said.Dr Pramod Tripathy, founder of ‘Freedom from Diabetes’ was quoted as saying, “hypothyroid, osteoporosis, diabetes, high cholesterol cardiovascular disease and cancer… all seemingly unrelated diseases have one thing in common. And that is, raised fasting insulin levels.”Insulin rises in the body because of insulin resistance. And insulin resistance increases because of excess fat, excess acid and insulin like growth factor (present in all animal products),” he said.Leading nutritionist and holistic wellness counselor Dr Ira Rattan said, “progression of PreDialysis Chronic Renal Failure (CRF) is slower on diets based on soya protein than on diets based on animal protein.”last_img read more