Month: August 2019

  • Physicists Transmit Light through Opaque Materials

    first_imgLeft: the light falls on the opaque paint layer as a plane wave and little is transmitted. Right: the waveform has been shaped and clear light is transmitted: the open channels have been found. Credit: Mosk and Vellekoop. University of Twente. No matter how thick an opaque “scattering material” is, physicists have shown how to weave light through tiny open channels in the material, so that the light passes through on the other side. Explore further Materials such as white paint, paper, and milk are considered opaque because they scatter (rather than absorb) light. When light encounters these scattering materials, it undergoes sub-surface scattering, deflecting in every direction. One prime example is the blinding whiteness of freshly fallen snow, which is caused by lots of scattering light.But theorists have predicted that, no matter how disordered these opaque scattering materials are, they still contain open channels that light could conceivably fit through. In the 1980s, scientists used random matrix theory to show that thicker materials have fewer open channels, but even the thickest materials should have some channels.Now, physicists Allard Mosk and Ivo Vellekoop of the University of Twente in The Netherlands have shown how to find these open channels, and how to control the shape of incoming light waves so that they can make their way through. Until now, manipulating the light so that the open channels could actually be found has been too complex.By shaping the light waves in a specific way, the physicists could reinforce the scattering waves with each other through constructive interference, and the light waves could then travel through an open channel in the material. In their experiments, the physicists focused a laser beam onto an opaque layer of white zinc oxide (a material used by painters such as Van Gogh). With a digital camera, they measured the light emerging from the other side, and used this information to control the shape of the incoming light wave with a computerized feedback loop.To change the light wave´s shape, the scientists slowed parts of the wave with a liquid crystal display. These delayed parts interfered with other parts of the same wave, and ultimately increased the amount of light reaching the camera by at least 44% compared with the initial unshaped wave.Even when the physicists doubled the opaque layer thickness from 5.7 to 11.3 microns, they still achieved a similar increase in transmission. They calculated that a maximum transmission of two-thirds of the incoming light is possible, which matches theoretical predictions.”However thick a material is, it should be possible to create a wave that can be transmitted,” Mosk said.The ability to transmit more light through opaque scattering materials may lead to several applications, such as better medical imaging technology. Also, since electrons behave as waves in the theory of quantum mechanics, this new approach may help electrons find and move through open channels in thin wires, such as those on semi-conductor chips. Further, the research could lead to a better understanding of radio waves for mobile communication, such as improving cell phone reception and range. Mosk and Vellekoop´s study, called “Universal optimal transmission of light through disordered materials,” will be published in an upcoming issue of Physical Review Letters. It is also available at arxiv.org.via: University of Twente and ScienceNOW SLAC makes ‘electron camera,’ a world-class tool for ultrafast science, available to scientists worldwide Citation: Physicists Transmit Light through Opaque Materials (2008, August 18) retrieved 18 August 2019 from https://phys.org/news/2008-08-physicists-transmit-opaque-materials.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

  • Intelligent Traffic System Predicts Future Traffic Flow on Multiple Roads

    first_img Counterintuitive physics may help everyone drive home quicker Explore further The researchers, Chuanfei Dong, et al, from the Georgia Institute of Technology, the University of Science and Technology of China, Syracuse University, and the University of Shanghai for Science and Technology, have recently reported the results of their new intelligent traffic system, called the prediction feedback strategy (PFS). In simulations, the researchers demonstrated that PFS could control traffic flow better than three other information feedback strategies. Even if only some drivers choose to use the information, the improved strategy could help to alleviate traffic congestion and enhance the capacity of existing infrastructure.“The greatest significance of our work is that PFS can predict the future situation of roads, so then we can know what will happen and how to prevent congestion in the future,” Dong told PhysOrg.com.While intelligent traffic feedback strategies have almost always been applied to two-route systems, in this study the researchers investigated how the strategies performed in a more complex three-route scenario. In this model, drivers choose one of three routes according to real-time information feedback. The researchers then performed simulations with strategies based on previous vehicles’ overall travel times (determined at the end of the route), the average velocity of vehicles (determined at various steps of the route), or congestion of each route, which is calculated by vehicles sending their location using GPS to a control center (determined at various steps of the route). Out of these three strategies, the last one that calculates congestion has shown to be most efficient.The researchers’ new strategy, PFS, takes the congestion information from the previous strategy, but then takes another step by predicting the road situation in the future based on the current road situation. By predicting the future, PFS can overcome a lag effect that hinders the other strategies. This advantage enables PFS to accommodate an increased vehicle capacity compared to the other strategies. Although the average vehicle speed is slightly slower using PFS (since more vehicles mean lower speed), the flux (which measures a combination of average velocity and vehicle density) is largest using PFS.“In [the previous strategies], the travel time reported by a driver at the end of two routes only represents the road condition in front of him, but perhaps the vehicles behind him have gotten into the jammed state,” Dong explained. “Unfortunately, this information will induce more vehicles to choose his route until a vehicle from the jammed cluster leaves the system. This effect apparently does harm to the system. On the other hand, PFS can predict the future situation of the road and the effects to the route situation caused by the traffic jam at the end of the traffic system; therefore, the new strategy may improve the road situation.”More information: • Dong Chuan-Fei, Ma Xu, Wang Bing-Hong, and Sun Xiao-Yan. “Effects of Prediction Feedback on Multi-Route Intelligent Traffic Systems.” arXiv:0909.5202v2• Prediction feedback in intelligent traffic systems, Physica A: Statistical Mechanics and its Applications, Volume 388, Issue 21, 1 November 2009, Pages 4651-4657, doi:10.1016/j.physa.2009.07.018Copyright 2009 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. In the three-route system, information on a display board lets drivers know the predicted future congestion of each of the three roads, helping drivers choose the fastest route. Image credit: Dong, et al. Citation: Intelligent Traffic System Predicts Future Traffic Flow on Multiple Roads (2009, October 12) retrieved 18 August 2019 from https://phys.org/news/2009-10-intelligent-traffic-future-multiple-roads.html (PhysOrg.com) — In urban areas, there’s almost always more than one way to get somewhere, but often it’s difficult to predict which road will be fastest. In an attempt to improve traffic flow and decrease congestion, researchers have been developing intelligent traffic systems that display real-time information about various roads on a display board, helping drivers make the best road choice. Until now, this information has always displayed traffic conditions from the immediate past. A new system can now predict future traffic conditions based on real-time data, giving drivers more relevant information to choose the fastest route. 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

  • Coevolution not healthy for the female sea monkey

    first_img Female guppies risk death to avoid sexual harassment Citation: Coevolution not healthy for the female sea monkey (2011, June 20) retrieved 18 August 2019 from https://phys.org/news/2011-06-coevolution-healthy-female-sea-monkey.html Artemia urmiana Sea monkeys, or brine shrimp, lay eggs that are tough in nature and are able to survive for long periods of time. They can lay dormant for years, as in the case of a drought, and then once the water returns are then able to hatch.Looking at the Great Salt Lake in Utah, researchers collected eggs from layers that had formed in 1985, 1996 and 2007. They took these eggs back to the lab and allowed them to hatch. Keeping each generation separate, the researchers then bred the females with eggs from their generation and previous and past generations.What they discovered was that the longer the time difference between the male and female partner, the sooner the female sea monkey died. When a female from 1985 was bred with a male from 2007, her life span was cut short by as much as 12 percent.The research seems to match the idea of sexual conflict and that female shrimp are best suited to breed with their own generation. It appears males and females adapt new mating strategies through different generations and this proves deadly for the female sea monkey.The change in sexual partners from a different generation did not however seem to have an effect on the female’s reproductive success. Even though they were dying faster, they were also producing eggs at a faster rate.The one mystery still puzzling the researchers is just how the males are harming the females and shortening their lifespan. (PhysOrg.com) — In a new study titled Male-Female Coevolution in the Wild: Evidence from a Time Series in Artemia Franciscana and published in Evolution, evolutionary ecologist Nicolas Rode from the Centre for Functional and Evolutionary Ecology looked at the sexual behavior of the sea monkey and what happened when females were bred with past and future generations. More information: MALE-FEMALE COEVOLUTION IN THE WILD: EVIDENCE FROM A TIME SERIES IN ARTEMIA FRANCISCANA, Evolution, DOI: 10.1111/j.1558-5646.2011.01384.xABSTRACTSexual conflicts are ubiquitous in nature and are expected to lead to an antagonistic coevolution between the sexes. This coevolutionary process is driven by selection on sexually antagonistic traits that can either be directional or fluctuating. In this study, we used dormant cysts of Artemia franciscana, collected in the same population in three different years over a 23-year period (corresponding to ∼160 generations in this system), to investigate male-female coevolution in natural conditions over time. We performed a cross experiment study where reproduction of females mated to males from the past, present or future was monitored until death. In agreement with a model of ‘fluctuating selection’, we found that females survived better and had longer interbrood intervals when mated with their contemporary males compared to when mated with males from the future or the past. However, female weekly and lifetime reproductive successes displayed no differences between contemporary and non-contemporary matings. Finally, the coevolutionary patterns (‘arms race dynamics’ or ‘fluctuating selection dynamics’) possibly acting on female relative fitness could not be discriminated. This study is the first direct demonstration that the process of male – female coevolution, previously revealed by experimental evolution in laboratory artificial conditions, can occur in nature on a short evolutionary time scale. 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. © 2010 PhysOrg.com Explore furtherlast_img read more

  • Skin gel allows wounds to heal without leaving a scar

    first_imgA team of researchers at Huazhong University of Science and Technology has developed a silk protein-based gel that they claim allows for skin healing without scarring. In their paper published in the journal Biomaterials Science, the group describes their gel and how well it works. © 2018 Science X Network Journal information: Biomaterials Science 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 More information: Chao Qi et al. Sericin hydrogels promote skin wound healing with effective regeneration of hair follicles and sebaceous glands after complete loss of epidermis and dermis, Biomaterials Science (2018). DOI: 10.1039/C8BM00934Acenter_img Scarring due to a skin injury is not just unsightly—for many, it can also be a painful reminder of a wound. For these reasons, scientists have sought a way to heal wounds without scarring. In this new effort, the team in China claims to have found such a solution—a sericin hydrogel.The gel used by the researchers was based on a silk protein—the researchers extracted sericin from silk fibers and then used a UV light and a photoinitiator to cross-link the protein chains. The result was a gel that adhered well to cells and did not trigger much of an immune response. The researchers note that it also has adjustable mechanical properties. They explain that the gel allows for scar-free healing by inhibiting inflammation and by promoting the development of new blood vessels. It was also found to regulate TGF-β growth factors, which resulted in stem cells being routed to the injury site allowing new skin to develop, rather than scar tissue.The researchers note that proteins found in silk have built-in bioactivity. This, they suggest, is likely because the composition of the amino acids is quite similar to that of human skin. The gel also blocks bacteria from entering a wound, which allows the wound to heal faster than it normally would.More study is required to ensure that the gel does not cause unwanted side effects, but the team is optimistic. They point out that it does a better job than anything else currently available at preventing scars from forming. They predict that their gel will one day soon be used to treat wounds in a way that is not only safe and effective, but prevents scarring. Credit: Biomater. Sci., 2018,6, 2859-2870 How does a frog heal wounded skin without scarring? Citation: Skin gel allows wounds to heal without leaving a scar (2018, November 5) retrieved 18 August 2019 from https://phys.org/news/2018-11-skin-gel-wounds-scar.htmllast_img read more

  • Cairn India board to meet today to discuss merger with Vedanta

    first_imgCairn India on Saturday said its board of directors will meet on Sunday to deliberate on the proposed merger with Vedanta Ltd.In a BSE filing Cairn India said: “A meeting of Board of Directors of the company will be held on June 14, 2015, inter alia, to consider and evaluate amalgamation of the company with Vedanta Limited.” Meanwhile, as per sources, boards of Cairn India and Vedanta Ltd at a meeting tomorrow will consider ‘reverse’ merger aimed at cutting debt on Vedanta books as well as the share swap ratio and decide on the timelines for completion of the merger. Vedanta in 2011 acquired majority control of Cairn India for $8.67 billion. It holds 59.9 per cent in the oil explorer through its various units as of March 31. As a prelude to the merger, Vedanta had this month bought some of the shares held by Agarwal’s Twin Star Mauritius Holdings to raise its stake in Cairn India to 23.71 per cent from 18.73 per cent. Twin Star now holds 34.43 per cent in Cairn India. Vedanta may at a later date merge its other cash cows, Hindustan Zinc Ltd and Bharat Aluminium, they said.last_img read more

  • Vishwas Bharti are antisocial elements

    first_imgThe Delhi Commission for Women (DCW) chief Barkha Shukla Singh on Thursday called AAP leaders Kumar Vishwas and Somnath Bharti as “anti-social elements” who have no respect for women. She also said that the complaint against Vishwas has been referred to police and has not been “dropped”. “They (Kumar Vishwas and Somnath Bharti) are anti-social elements who enjoy Chief Minister Arvind Kejriwal’s protection. They have no respect for women and      for the Commission. I urge Chief Minister Kejriwal to take action against them,” Singh said.last_img read more

  • Feeling the Korean vibe

    first_imgPSY’s 2012  smash hit Gangnam Style had the entire world hooked. The single was one of the most watched Youtube videos of all time. To hardcore K-pop fans, though, Gangnam Style is just the tip of the iceberg. The Sunday crowd at the Siri Fort auditorium attending the Feel Korea live concert was filled with such hardcore K-pop enthusiasts as well as casual fans.The Korean Culture Centre India, the organization behind the success of the first ever K-pop concert in India, N-SONIC in 2014, promised that Feel Korea would be grander than its predecessor.  Also Read – ‘Playing Jojo was emotionally exhausting’The concert had  all the ingredients associated with a high octane pop concert. the performers were high on energy that gave the audience the perfect adrenaline rush. K pop bands, ZE:AJ, 100%, Bestie, Almeng, IMFACT and Teen Top took to the stage and belted out their respective chartbusters, one after the other. Each band got its fair share of applause but the final band, Teen Top were clearly the show stealers. Everything they did was met with a thunderous applause. For most of the bands, it was their first ever visit to India. But, after receiving such overwhelming crowd support, they stated that they can’t wait to come back here.  With K-pop slowly and steadily carving a niche for itself  in the international music scene, the sky is the limit for these performers.last_img read more

  • Fiercest clashes as Syria regime advances with Russian support

    first_imgSyrian state television said regime forces had captured the village of Kafr Nabuda in Hama province, where they are pressing an operation on both sides of the strategic Damascus-Aleppo highway.However, the Syrian Observatory for Human Rights monitor said clashes were ongoing after regime forces entered the village.“Regime forces captured the southern district of Kafr Nabuda backed by more than 20 Russian air strikes,” Observatory director Rami Abdel Rahman said. Also Read – Nine hurt in accident at fireworks show in French resort“The clashes are the fiercest since the Russian air campaign began on September 30.” Syrian government forces appear to be targeting the town of Khan Sheikhun, which lies on the strategic highway just across the provincial border in neighbouring Idlib.Many of Russia’s air raids so far have focused on the area where the borders of Hama, Idlib and Latakia provinces meet.Latakia province on the Mediterranean coast is a stronghold of the regime and the location of President Bashar al-Assad’s ancestral village. Also Read – Pakistan Army ‘fully prepared’ to face any challenge: Army spokesmanIdlib province is controlled by a powerful rebel alliance called the Army of Conquest which includes Al-Qaeda affiliate Al-Nusra Front.In recent months, the alliance has sought to expand from Idlib into Hama and the strategic Sahl al-Ghab plain between the three provinces in a bid to target Latakia.Abdel Rahman said the rebels were sending reinforcements to Kafr Nabuda to battle the regime, which was also shelling other parts of Hama and Latakia provinces. A military source, meanwhile, told AFP regime forces had taken at least five villages in northern Latakia province since they began their ground operations in tandem with Russian strikes.Moscow began air strikes in Syria at the end of last month, saying it was targeting the Islamic State group and other “terrorists”.But rebels and their backers accuse the Russians of targeting mainly non-jihadist groups.Elsewhere in Syria, a military source said regime forces had captured the “duty-free zone” area north of the city of Aleppo from rebels.Aleppo city is divided between rebel control in the east and government control in the west, but the situation is largely reversed in the countryside surrounding the city.The source said the regime advance would help protect territory it holds in the area, including the Sheikh Najjar industrial area to the city’s east.last_img read more

  • Body of constable found with slit throat in Kalna

    first_imgKolkata: Mystery shrouds the death of a police constable whose body was found from a police outpost in Kalna with his throat slit.The incident took place on late Monday evening. According to the district police,the deceased might have committed suicide.A detailed probe is underway in this connection.It has been learnt that constable Mekhali Mandi (53), a resident of Nalhati in Birbhum, was posted at Bulbulitala police outpost under Kalna police station. Also Read – Rain batters Kolkata, cripples normal lifePolice said that the deceased had gone to the kitchen of the police barrack in the evening. Sometime later, the other policemen entered the barrack and found Mandi lying in a pool of blood. They rushed him to Kalna Sub-Divisional Hospital, where the doctors pronounced him brought dead.According to the preliminary investigation, the district police suspect that Mandi had slashed his throat with a knife. The knife that he might have used while committing suicide has already been seized by the investigating officers.The family members of Mandi have demanded a high level probe into his unnatural death. They said that he might have committed suicide after failing to bear some psychological pressure. The family members also said that there may be some foul play behind his death.last_img read more

  • The art of queue jumping and Indians

    first_imgWhat is in a queue, most Indians ask as they invent innovative ways of queue-jumping, says a new book on the most striking characteristic that literally binds the diverse nation.“People of every caste, creed, language, state, religion, province and street differ on virtually every other issue, but we all converge on this one ethos: the ethos of queue-jumping,” says V Raghunathan in his book ‘The Good Indian’s Guide To Queue Jumping’, published by HarperCollins. Also Read – Add new books to your shelfAccording to him, Westerners and Indians are as different as chalk and cheese when it comes to queuing with Western queues mostly a “lifeless, boring and linear assortment of people standing somberly as if struck by life’s most extreme tragedy”.But not so with Indians. “Our average queues are full of verve and vitality, each brain in overdrive, actively evaluating all strategies to jump the queue,” he writes.“What is more, in our queues we stand really tight, unlike the Westerners, who stand apart as if the next person may be suffering from some unmentionable contagion. That is why our queues, when they exist at all, are a solid, albeit uneven, line of people with all senses on alert, rather than the relaxed and limp lines seen in the West,” he goes on to add. Also Read – Over 2 hours screen time daily will make your kids impulsive“In a nation of a billion people, there is no escaping queues. We find ourselves in one every day – whether to board the flight or if we are less fortunate to fetch water from a municipal tap. We no longer wait for years for a Fiat car or a rotary-dial phone but there are still queues that may last days, like those for school admissions. And then, there are the virtual ones at call centres in which there’s no knowing when we will make contact with a human,” the book says. Raghunathan says that no wonder the disregard for queues has also found its way into the very folklore of the nation via Bollywood when “Amitabh Bachchan growled in his bass voice in Kaalia (1981), ‘Hum jahan khade ho jaate hain, line wahin se shuru hoti hai’, saying in effect I will always jump to the head of the queue: stop me if you dare”. The objective of his book, he says, is to enhance the wisdom evolved by Indians about queue-jumping.He also touches on another important aspect related to queues professional queuers.“The basic idea of paying someone to stand as your proxy in a queue is neither terribly original nor new. Many of us have, at one time or the other, paid someone to line up on our behalf at a railway reservation counter or at the American embassy.“But these efforts can at best be described as jugaad an ad hoc way to address the queuing problem. They never evolved into a full-time entrepreneurial venture, leave alone a full-fledged corporate business, even if not listed on the stock exchange as is the case in some places,” the book says.Raghunathan terms queue-jumping in India as a troubling social phenomenon, made alarmingly ugly by the total refusal of service providers, regulators and society alike to apply their minds.“It is never on our list of foremost concerns to address. But queue-jumping is only a symptom of our larger social apathy, corrupted mindset, the wide gap between the powerful and the common folk, our innate indifference to fairness ad concern for others, and the complete denial that we have a problem in the first place.“It is a problem symptomatic of deeper ones so that it appears queue-jumping is going to be around for a very long time,” he says.He feels a weak regulatory system encourages queue-jumping in all formats, which in turn makes the enforcement of measures to curb queue-jumping increasingly more difficult.“This clearly implies that first and foremost we need to recognise that queue-jumping, especially in a country where queues are an important social reality, is a problem worthy of being tackled,” Raghunathan writes.last_img read more