Month: August 2019

Machines might talk with humans by putting themselves in our shoes

first_img Citation: Machines might talk with humans by putting themselves in our shoes (2007, September 10) retrieved 18 August 2019 from https://phys.org/news/2007-09-machines-humans.html In a preliminary investigation, Moore constructed a humanoid robot called “ALPHA REX” that uses the PRESENCE hierarchical structure to demonstrate the relatively simple task of human-machine synchronization. As a human uttered the words “one, two” spoken at regular intervals, the robot generated taps. An overall control loop generated an error signal, which in turn modified the robot’s tapping rhythm until it matched the human’s words. Synchronization occurred by the eighth count, whereas a conventional model would require the robot to compute complex analytical solutions and suffer system delays. Further, because ALPHA REX could anticipate the human’s behavior, it tapped one extra time after the human ceased counting. While it sounds simple, these kinds of coordination, reaction, and prediction abilities are necessary for the PRESENCE model, where behavior is quickly altered in response to the environment in order to achieve a desired state. As Moore explains, PRESENCE is less about speaking or listening, but about the human and machine interacting to meet each other’s needs. Again, this is in sharp contrast to conventional models that rely on the breakdown of components such as speech recognition, generation and dialogue. Future machines that use PRESENCE could provide a variety of applications, such as robot companions or hands-free, eyes-free information retrieval. Moore predicts that PRESENCE machines could produce appropriate vocal intonations, volume levels, and a degree of emotion that is absent in current systems. He even suggests that the new machines could help unify currently divergent fields, such as speech science and technology; natural, life and computer sciences; and provide insight into fields in neurobiology that inspired PRESENCE itself.Finally, Moore explains that it is very difficult to predict the speed and degree of progress in the future of human-machine speech.“If we simply continue with the current research paradigm (which is mainly training on more data),” Moore said, “then for automatic speech recognition to compete with alternative technologies (e.g. keyboards etc.), it would need to be half as good as human speech recognition (i.e. it doesn’t need to be ‘super-human’)—and that is five times better than it is today. And the time until this would happen? In about 20 years if progress of the past 10 years can be sustained, or, if it can’t (which is most likely), then [possibly] never!”Citation: Moore, Roger K. “PRESENCE: A Human-Inspired Architecture for Speech-Based Human-Machine Interaction.” IEEE Transactions on Computers, Vol. 56, No. 9, September 2007.Copyright 2007 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. The humanoid robot ALPHA REX demonstrated the core principles of PRESENCE, as it synchronized its own behavior with that of a human. Image credit: Roger K. Moore. Roger Moore, a computer scientist at the University of Sheffield in the UK, thinks that the current bottom-up architecture of speech-based human-machine interactions may be flawed. He is concerned because, although the quantity of training data for machines has increased exponentially, machines are still poor at understanding accented or conversational speech, and lack individuality and expression when speaking.Moore has recently suggested an alternative model for speech-based human-machine interaction called PRESENCE (PREdictive SENsorimotor Control and Emulation). While the conventional reductionist architecture views spoken language as a chain of transformations from the mind of the speaker to the mind of the listener, PRESENCE takes a more integrative approach. As Moore explains, PRESENCE focuses on a recursive feedback control structure, where the machine empathizes with the human by imagining itself in the human’s position, and then changes its speech patterns accordingly.“The main difference between PRESENCE and current approaches to spoken language technology is that it offers the possibility of, one, unifying the processes of speech recognition and generation (thereby reducing the number of parameters that have to be estimated in setting up a system) and, two, linking low-level speech processing behaviors to high-level cognitive behaviors,” Moore told PhysOrg.com. “This should give a PRESENCE-based system a considerable advantage over more conventional systems that treat such processes as independent components, and then struggle to integrate them into a coherent overall system.”Moore’s model is inspired by recent results in neurobiology—such as the communicative behavior of all living systems, and the special cognitive abilities of humans—that aren’t directly related to speech. Nevertheless, the results have provided a number of implications for human-machine speech, such as the strong relationship between sensor and motor activity, and the power of negative feedback control and memory to predict and anticipate future events.“A key idea behind the PRESENCE architecture is that behavior is driven by underlying beliefs, desires and intentions,” Moore explained. “As a consequence, behavior is interpreted with respect to one organism’s understanding of another organism’s beliefs, desires and intentions. That is, the ‘meaning’ of an observed action is derived from the estimated beliefs, desires and intentions that lie behind it—an individual is only able to make sense of another’s actions because they themselves can perform those actions. This is precisely a manifestation of the empathetic or mirror relationships that can exist between conspecifics (members of the same species).”center_img While robots can do some remarkable things, they don’t yet possess the gift of gab. Since the 1970s, researchers have been trying to develop a speech-based human-machine interface, but improvements are gradual, and some fear that the performance of current systems may not reach an adequate level for real-world applications. 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

Bizarre giant oarfish filmed w Video

first_imgA 4 m long Oarfish washed ashore at Anna Marie Island, South of Tampa Bay, Florida, March 2002. © Duke Miller, via Australian Museum. © 2010 PhysOrg.com (PhysOrg.com) — A rare giant oarfish, probably the largest bony fish in the ocean, has been filmed off the Gulf of Mexico. This is possibly the first time the fish has been observed in its natural environment. Citation: Bizarre giant oarfish filmed (w/ Video) (2010, February 10) retrieved 18 August 2019 from https://phys.org/news/2010-02-bizarre-giant-oarfish-video.html Oarfish that washed ashore on a Bermuda beach in 1860. The animal was 16 feet (4.9 m) long and was originally described as a sea serpent. Image: Ellis, R. 1994. Monsters of the Sea. Robert Hale Ltd. (via Wikipedia) Professor Benfield said to his knowledge the oarfish had never before been seen alive in the ocean’s mesoplagic layer (200-1000 meters deep), although there was a possible sighting in 2007 at 765 meters deep off the coast of Africa. He said the fish’s swimming behavior was particularly interesting because it undulated its dorsal fin in waves, and that drove it backwards at “quite a good speed”.During the project the team also filmed the behavior of a manefish (Paracaristius sp.) for the first time in its natural habitat, and this sighting was reported in the Copeia journal. Manefish are normally only seen dead in trawls, and Benfield said in that state they are “incredibly beat up,” but in its natural environment it is a good swimmer, with fins splayed out like a parachute. The manefish is thought to feed on, or take food from, a siphonophore, which resembles a jellyfish, and which has tentacles that could damage the fish. This could explain the precise control the fish has over its position and orientation.The Serpent project is run by the National Oceanography Centre, Southampton (NOCS). Professor Benfield said he hopes the project will establish a system for deep-sea observation, with numerous ROV-equipped rigs and ships surveying the Gulf.Mark Benfield is a professor with the Department of Oceanography and Coastal Sciences at Louisiana State University, Baton Rouge in the U.S. More information: — Journal paper: www.asihcopeiaonline.org/perls … =10.1643%2FCI-08-126– Wikipedia article: en.wikipedia.org/wiki/Oarfish Oil companies help marine biologists to explore new frontiers in deep-sea oceanography The oarfish (Regalecus glesne) can reach up to 17 m (55 ft) long. It has rarely been seen before, and then only when dying on the surface or washed up on shore, dead. It is the longest fish known and has a prominent, undulating dorsal fin, and it may have spawned the ancient tales of sea serpents.Professor Benfield and his team filmed the oarfish at over 1500 feet deep during a Serpent project survey in the Gulf of Mexico. The project is run by marine scientists in collaboration with oil companies like Shell, BP and Chevron. The team used remotely operated vehicles (ROVs) supplied by the energy companies to survey the waters deep under the Thunderhorse semi-submersible oil rig.The scientists initially thought the 5-10 meter (15-30 ft) long fish was a pipe riser dropped by the energy companies. It was vertical and shiny, and looked like a big riser nearby, but as they looked closer and saw it moving they realized it was an oarfish. It swam vertically downwards tail first when the ROV approached. The vehicle followed the oarfish for around five minutes and then resumed the survey. 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.last_img read more

Mechanical logic gate Could levers replace transistors

first_img 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. SEM image of a released SiC NEMS switch with 3 μm length. Image credit: Science, DOI:10.1126/science.1192511 Organic flash memory developed Explore further More information: Te-Hao Lee, Swarup Bhunia, Mehran Mehregany, “Electromechanical Computing at 500°C with Silicon Carbide,” Science (September 2010). Available online: www.sciencemag.org/cgi/content … stract/329/5997/1316Paul Marks, “Steampunk chip takes the heat,” New Scientist (September 10, 2010). Available online: www.newscientist.com/article/d … -takes-the-heat.htmlHamish Johnston, Logic circuit takes the heat,” Physicsworld (September 14, 2010). Available online: physicsworld.com/cws/article/news/43734. (PhysOrg.com) — Back in the Victorian period, Charles Babbage created a mechanical computer that made use of levers and cogs to get data moving. These days, though, our computers are mostly run using electronic transistors. Nothing too mechanical about those. Unfortunately, when putting together a logic gate for use in computing, the materials used can’t withstand some of the heat. Silicon carbide has been used to help fortify regular silicon, which degrades at 250 to 300 degrees Celsius. However, silicon carbide transistors are bulky and slow — and require high voltages. Citation: Mechanical logic gate: Could levers replace transistors? (2010, September 17) retrieved 18 August 2019 from https://phys.org/news/2010-09-mechanical-logic-gate-levers-transistors.html In order to get around this problem Te-Hao Lee and a team at Case Western Reserve University turned back to Babbage and his idea of mechanical computing. New Scientist reports on the effort to integrate mechanical computing into our modern electronic systems:His team has developed a mechanical version of an inverter – the building block used to construct many types of logic gate, which themselves are a fundamental component of digital circuitry within computers. The device uses an arrangement of nanoscale levers instead of transistors. Like a telegraph operator’s Morse key, these levers physically make and break contact to pass or block currents.Application of a voltage makes the levers move under electrostatic attraction. At 550 °C Lee’s team managed to get the inverter to switch on and off 500,000 times a second – performing a computation with each cycle.Such operating temperatures are encouraging. However, there are problems. The mechanical components start to break down after two billion cycles, limiting their usefulness. Additionally, this set up is still slower than the speeds even a normal PC sees. However, the main uses for a mechanical logic gate likely wouldn’t be in consumer computing. Instead, such a device would make more sense in situations of very high heat, such as for rocket engines. © 2010 PhysOrg.comlast_img read more

Siris abortion info flap Blame it on Beta says Apple

first_imgSiri is the intelligent iPhone personal assistant smart enough to give you an answer just by asking—unless your question is where to find the closest abortion clinic. In a fast and furious go-round this week, the American Civil Liberties Union (ACLU), abortion rights supporters, bloggers, and Apple itself traded notes about Siri’s inability to provide an answer to questions about where to go for birth control and abortion. Citation: Siri’s abortion info flap: Blame it on Beta, says Apple (2011, December 1) retrieved 18 August 2019 from https://phys.org/news/2011-12-siri-abortion-info-blame-beta.html © 2011 PhysOrg.com Explore further More information: www.rawstory.com/rs/2011/11/29 … tead-of-an-abortion/www.prochoiceamerica.org/media … pr11302011_siri.htmlbits.blogs.nytimes.com/2011/11 … nswers-are-a-glitch/secure.aclu.org/site/SPageServ … 11130_apple_abortioncenter_img Siri gives iPhone 4S sass Jenna Wortham in The New York Times brought this odd blank on the part of Siri to attention on Tuesday.“Try asking it to find a local abortion clinic, and the software turns up a puzzling blank — even in areas that clearly have such clinics,” she said. When Siri was asked to find an abortion clinic in New York City, Siri replied, Sorry, I couldn’t find any abortion clinics.”Megan Carpentier, the executive editor of The Raw Story, found that Siri users in the Washington, D.C., area were directed to antiabortion centers in Virginia and Pennsylvania instead of at a nearby Planned Parenthood. “Ask Google the same question, and you’ll get ads for no less than seven metro-area abortion clinics, two CPCs and a nationwide abortion referral service,” she wrote.“Apple’s Latest iPhone Has No Problem Pointing Users to Viagra, But Comes Up Blank on Birth Control, Abortion,” headlined a bothered ACLU on its blog “Blog of Rights,” and asked all of its readers to send a template-provided email message to Apple to voice concern. “Send a message to Apple: Fix Siri.”The text message read “I urge you to correct this glitch, so Siri provides the same service to women seeking information about vital reproductive health care services as to users seeking Viagra, burgers, and other services.”What also annoyed the ACLU is that, when Siri did provide replies for abortion queries, Siri directed questioners to pregnancy crisis centers. “These centers often bill themselves as resources for abortion care, but do not provide or refer for abortion and are notorious for providing false and misleading information about abortion to women,” said the ACLU.To be fair to Apple, Siri’s co founder, Norman Winarsky–Siri was bought by Apple last year—pointed out that the inability of Siri to answer these kinds of question may be due to the third-third-party Web services that Siri uses, rather than a deliberate policy decision by Apple to withhold abortion clinic information. Since the Web services provide local business information, he said, it may be possible Apple was not aware of all the results that come up.Fundamentally, Apple’s response has been Blame it on Beta. In response to The New York Times flag about Siri being clueless, Apple said Siri’s cluelessness was not intentional. Natalie Kerris, spokesperson for Apple, said, “These are not intentional omissions meant to offend anyone. It simply means that as we bring Siri from beta to a final product, we find places where we can do better, and we will in the coming weeks.”Meantime, Nancy Keenan, president of NARAL Pro-Choice America Foundation, sent a letter to the CEO of Apple, Tim Cook, expressing concern about Siri: “It is disappointing to read that a tool like Siri is missing the mark when it comes to providing information about such personal health issues as abortion care and contraception.” 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

Japanese association unveils tapelike environmental sensors

first_imgCredit: Tech-ON More information: via Tech-ON: techon.nikkeibp.co.jp/english/ … _EN/20130709/291562/ The need for inexpensive and easy to deploy sensors has become more critical as governments around the world have become more aware of the dangers of environmental factors, particularly those that are man-made. Current sensors generally involve a person making the rounds, retrieving modules to take back to a central location for testing—an expensive and time consuming process. The thinking is that if small easy to install sensors could be used that send data automatically, than many more of them would be put into service, making life safer for everyone in the vicinity. Project leaders hope such sensors can be deployed en masse in factories, schools, office buildings, hospitals, etc. across the country.Each sensor, once deployed, becomes part of a network via wireless communications and can be configured to detect a variety of environmental factors such as CO2, temperature, VOC, infrared light, dust, and even electromagnetic field strength. The sensor measures the amount detected and relays that data to a central processing unit. Besides being small and easy to install, the sensors are inexpensive as well, with a cost per unit expected to be less than $10. Amazingly, the sensors also power themselves.Each sensor is a three layer construct: a highly integrated MEMS sensor, an antenna and a power generation and storage layer. The power layer is a thin, flexible, organic semiconductor nanofiber that is still under development. The current version is able to supply 80 percent of the power needed. The researchers hope to bump that to 100 percent before offering the sensors to the public. Citation: Japanese association unveils tape-like environmental sensors (2013, July 10) retrieved 18 August 2019 from https://phys.org/news/2013-07-japanese-association-unveils-tape-like-environmental.html Novel adaptive management system boosts efficiency of wireless sensor networks that monitor surrounding environments Explore further © 2013 Phys.org 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. (Phys.org) —Green Sensor Network Laboratories of NMEMS TRA, a technical research association in Japan, has unveiled a new type of environmental sensor that is very small and easy to install. With a surface area of just 2 x 5cm and 1mm thick it attaches to surfaces much like a piece of tape. The development of the sensor was part of a larger nationwide project called “Sensor System Development Project to Solve Social Problems”—its goal is to foster the development of inexpensive and easy to deploy sensors for monitoring a host of sites for environmental conditions.last_img read more

Motorolas Woodside on Ara How do we modularize the phone

first_img MKBHD Hangout with Motorola CEO Dennis Woodside The dscout.com/ara site announced that “Motorola is inviting people across the globe to become Ara Scouts. Over the next six to 12 months, we’ll be doing research to shape the direction of Project Ara. You can help by collaborating with us on special missions.” © 2013 Phys.org On December 6, Motorola Mobility CEO Dennis Woodside brought the vision into further perspective in an interview streamed live with “YouTuber” and tech reviewer Marques Brownlee. Motorola’s vision is fundamentally one of a smartphone user having a skeleton that holds together a set of components and those components slide in and out. (“The endo [endoskeleton] is the structural frame that holds all the modules in place. A module can be anything, from a new application processor to a new display or keyboard, an extra battery, a pulse oximeter—or something not yet thought of,” according to the Ara team.)But why? The idea behind Ara, said Woodside, is, what, for example, if you could change the camera on the phone to one with super zoom properties? Today, he said, once you buy the phone, it cannot change that much. The software can change but not the hardware. A tantalizing opportunity emerges for the future of smartphones, where one thinks not only of innovating but of enabling others to innovate Motorola’s question became, “How do we modularize the phone?” 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. Consumers, he said, may want to do different things with their phones at different times of their lives. If going on a trip, the user may want a different camera, etc. As part of the project, Motorola has opened a site to solicit participants in Project Ara, and participants are in turn given missions that are idea-driven, he said, such as, “Come up with an idea for a new sensor that we can incorporate into a Project Ara phone.””So we are going to see where it goes,” he said. “Will we have a product in the next 12 months? It’s hard to say, but we are pretty excited about what we are doing.” More information: www.dscout.com/aramotorola-blog.blogspot.com/201 … ticky-hello-ara.htmlcenter_img Motorola studying modular smartphone (Phys.org) —”Goodbye Sticky. Hello Ara.” That was the blog title back in October on the Motorola Mobility site that grabbed phone watchers’ attention and inspired one common question: How soon can you do this? Ara is the name of Motorola’s Project that is working on a free, open hardware platform for creating highly modular smartphones. “We want to do for hardware what the Android platform has done for software: create a vibrant third-party developer ecosystem, lower the barriers to entry, increase the pace of innovation, and substantially compress development timelines,” said Paul Eremenko, and the Ara team. Citation: Motorola’s Woodside on Ara: How do we modularize the phone? (2013, December 9) retrieved 18 August 2019 from https://phys.org/news/2013-12-motorola-woodside-ara-modularize.html Explore furtherlast_img read more

Microbes may encourage altruistic behavior

first_img 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. (Phys.org)—Why do people commonly go out of their way to do something nice for another person, even when it comes at a cost to themselves—and how could such altruistic behavior have evolved? The answer may not just be in our genes, but also in our microbes. Explore further In a new paper, researchers Ohad Lewin-Epstein, Ranit Aharonov, and Lilach Hadany at Tel-Aviv University in Israel have theoretically shown that microbes could influence their hosts to act altruistically. And this influence could be surprisingly effective, with simulations showing that microbes may promote the evolution of altruistic behavior in a population to an even greater extent than genetic factors do.”I believe the most important aspect of the work is that it changes the way we think about altruism from centering on the animals (or humans) performing the altruistic acts to their microbes,” Hadany told Phys.org.It’s already well-known that microbes can affect the behavior of their hosts, with a prime example being how the rabies virus increases aggressive behavior in infected individuals. Research has also shown that the microbiome—the community of microorganisms that inhabit our gut—can even manipulate the hosts’ social behavior by infecting neurons and altering neurotransmitter and hormone activity.Against this backdrop, the researchers in the new study have proposed that microbes may induce a person to help others because the close physical contact (for example, food-sharing, co-sheltering, and grooming) increases the transmission of the microbes from one person to another. So when someone does something nice for us, we are not just the recipient of a kind act, but also of their microbes.To show that this idea can have a prevailing effect on a population over time, the researchers designed simulations of interacting individuals, some with altruism-inducing microbes, and some without. Then using a prisoner’s dilemma payoff scheme, the researchers investigated what happens to this population, its microbes, and its altruistic behavior over many generations.The results showed that, as long as horizontal transmission (between individuals) of microbes is allowed, altruism-inducing microbes can take over the population, leading to microbe-induced altruism. This result occurs even when only a very small percentage of the population initially carries these altruism-inducing microbes. The simulations also revealed that the evolution of altruism is successful because the microbes have a chance to either meet genetically related microbes in the recipient or infect and transform some of the recipient’s microbes into relatives.In a variation of this model in which altruism can also be induced by host genes, the researchers found that genetically encoded altruism does not evolve, but microbe-induced altruism continues to evolve whether or not genetic factors are present. Further simulations showed that, although there are some cases in which altruism encoded in genes can persist, microbe-induced altruism persists more often. Overall, the results suggest that microbes may play a dominant and previously overlooked role in the evolution of altruistic behavior.If microbes do exert such large sway on altruistic behavior, then it raises other intriguing questions, such as whether antibiotics, probiotics, and foods affecting the microbiome may influence the altruistic behavior of their hosts. In the future, the researchers plan to address these possibilities, as well as to test the theory.”We are now collaborating with experimental biologists in order to empirically validate the predictions of our theory,” Hadany said. Study reveals some secrets of how microbes and their genes traverse the globe Journal information: Nature Communicationscenter_img More information: Ohad Lewin-Epstein, Ranit Aharonov, and Lilach Hadany. “Microbes can help explain the evolution of host altruism.” Nature Communications. DOI: 10.1038/ncomms14040 © 2017 Phys.org Citation: Microbes may encourage altruistic behavior (2017, January 30) retrieved 18 August 2019 from https://phys.org/news/2017-01-microbes-altruistic-behavior.html (Left) The payoff matrix and (right) an illustration of horizontal transmission probability of microbes between hosts. Using this model, researchers have found that microbes may induce their hosts to help other hosts, benefitting the microbes and the other hosts, but not always the original hosts. Credit: Lewin-Epstein et al. Nature Communicationslast_img read more

Cicada wings help researchers design better solar cells

first_img © 2017 Phys.org (Phys.org)—Researchers have turned to cicada wings to design surfaces with highly antireflective properties, which have potential applications for solar cells, stealth surfaces, antifogging materials, and other optical applications. 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: Imran Zada et al. “Multifunctional, angle dependent antireflection, and hydrophilic properties of SiO2 inspired by nano-scale structures of cicada wings.” Applied Physics Letters. DOI: 10.1063/1.4986133 (Left) Photograph of a cicada, (center) SEM image of nanostructures on cicada wings, and (right) 3D AFM image of cicada wings. Credit: Zada et al. ©2017 American Institute of Physicscenter_img Journal information: Applied Physics Letters Cicada wings inspire antireflective surfaces As researchers Imran Zada et al. at Shanghai Jiao Tong University in China explain in a recent issue of Applied Physics Letters, cicada wings have nanoscale structures that give them exceptional antireflective properties, allowing them to transmit or absorb close to 100% of visible light. When it comes to solar cells, antireflective properties play an important role since absorbing more light leads to a better overall performance.In their paper, the researchers explain how they fabricated a silicon dioxide surface (an inexpensive material that is commonly used to make windows and camera lenses) with the same nanostructured pattern as cicada wings (which are made mostly of chitin) by using the wings as a template. By treating biological cicada wings in a solution containing silicon dioxide, then exposing the treated wings to high-intensity ultrasound, and finally allowing the wings to solidify so that the wings can be separated from the silicon dioxide material, the researchers were able to fabricate biomorphic silicon dioxide surfaces with the same nanostructured pattern that the cicada wings have. “Our work demonstrates that silicon dioxide with an antireflective structure can be directly fabricated from cicada wings through a simple and inexpensive sol-gel assisted ultrasonic method,” coauthor Wang Zhang at Shanghai Jiao Tong University told Phys.org. “The material exhibits a high performance of antireflective properties in the visible wavelength range at a wide range of incident angles.”Tests revealed that the new surfaces have a very low reflectance, absorbing as little as 0.3% of visible light. The reflectance properties vary depending on the incident angle of the light, however, and increase to 3.3% with increasing incident angles of the light. The researchers explain that the good antireflection properties arise due to the nanostructured pattern of the wings, in which the nanostructures’ dimensions are smaller than the wavelength of light. This pattern creates a continuously graded refractive index profile from air to the material’s surface, which essentially provides a pathway for light rays to enter the material and prevents them from reflecting back out.Although cicada wings are naturally superhydrophobic, the researchers were able to tune this property on the silicon dioxide surface by changing its chemical composition, transforming it into a hydrophilic material. With hydrophilic properties, the surface easily forms hydrogen bonds with water molecules. Combined with the material’s antireflective properties, this has the effect of preventing fog formation, suggesting potential applications for anti-fogging and self-cleaning optical materials. The researchers plan to explore these kinds of applications in future work.”In the future, our work is headed toward fabricating high-refractive-index materials with antireflective structures to study their multifunctional properties, such as antireflection, antibacterial activity, and superhydrophobicity,” Zhang said. Citation: Cicada wings help researchers design better solar cells (2017, November 3) retrieved 18 August 2019 from https://phys.org/news/2017-11-cicada-wings-solar-cells.htmllast_img read more

New millisecond pulsar discovered

first_img 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 Pulsars are highly magnetized, rotating neutron stars emitting a beam of electromagnetic radiation. The most rapidly rotating pulsars, with rotation periods below 30 milliseconds, are known as millisecond pulsars (MSPs).One of methods to identify new pulsars is searching for the circularly polarized emission that is almost unique to objects of this type. A team of astronomers led by David L. Kaplan of University of Wisconsin-Milwaukee, employed this method using ASKAP.The researchers have identified a highly polarized steep spectrum point source, designated ASKAP 143121.2−632809, in a deep pointing with ASKAP at 888 MHz. After rejecting the stellar origin of this newly found source, they classified it as a new MSP and gave it the designation PSR J1431−6328.”The Parkes observations confirm discovery of a pulsar associated with ASKAP 143121.2−632809.” the astronomers wrote in the paper.As noted in the paper, the newly identified pulsar has a spin period of approximately 2.77 ms and dispersion measure at a level of about 228.27 parsecs/cm3. The pulsar’s mass is estimated to be around 1.4 solar masses.Like more than half of known MSPs, PSR J1431−6328 was found to have a companion star. The astronomers assume that the secondary star could be a white dwarf with an estimated mass of about 0.31 solar masses. The system’s period was calculated to be most likely 64.3 days.The researchers noted that although PSR J1431−6328 does not yet appear to be particularly remarkable, it was relatively hard to discover. This is due to its short spin period, wide profile and high dispersion measure, what make it challenging to find it through traditional blind periodicity searches.”Note that while this pulsar was detectable in the HTRU [high time resolution-south] observation, the low period and high DM [dispersion measure] mean that it does rank rather low in ‘detectability,'” the astronomers wrote.Therefore, the discovery of PSR J1431−6328 proves that ASKAP could discover MSPs that are hard to find via traditional surveys. The researchers note that generic deep and shallow ASKAP surveys at 900 MHz, in particular, have the potential of finding more sources like the newly detected pulsar, including MSPs.”For a 15 percent polarized fraction, a deep ASKAP survey is as competitive as the HTRU high-latitude survey. Moreover, MSPs have a larger scale galactic height compared to normal pulsars, suggesting that all-sky ASKAP surveys may discover a number of high-|b| MSPs,” the researchers concluded. More information: Serendipitous Discovery of PSR J1431-6328 as a Highly-Polarized Point Source with the Australian SKA Pathfinder, arXiv:1908.03163. arxiv.org/pdf/1908.03163.pdf Folded pulse profile of PSR J1431−6328, from the Parkes observation of May 27, 2019. Image credit: Kaplan et al., 2019. Mass estimated for two binary pulsars Citation: New millisecond pulsar discovered (2019, August 13) retrieved 18 August 2019 from https://phys.org/news/2019-08-millisecond-pulsar.html Astronomers have reported a serendipitous discovery of a new millisecond pulsar as part of an observational campaign using the Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The newly detected pulsar has a spin period of about 2.77 ms and received designation PSR J1431−6328. The finding is detailed in a paper published August 8 on the arXiv pre-print repository. © 2019 Science X Networklast_img read more

In the Punjabi mood

first_imgDelhi was on its feet as a folk musical event was organised as part of the ongoing Mela Phulkari celebrations at IHC by Harinder Singh and  Kirandeep Singh. The special guest present at the event, film director Imtiaz Ali shared his love for Punjab and also that his films have always been inspired by Punjab. He also promised to promote Punjab and use it more often in his films.The event marked the performances of Jasbir Jassi, Punjabi singer and actor  and Pammi Bai with his troupe. Visitors were greeted by traditional musical instruments like sarangi, nagada, dilruba and dhad. The concept was aimed at serenading urban Delhites and pampering their senses. The event saw a revival of art, craft and culture in the feistiest form. Jassi flattered the audience with his song Punjab written by Gurpreet Ghuggi, while Pammi Bhai sang- Allah Jaane, Jugni, Mele Vich Paenda, Gidda.  Also Read – ‘Playing Jojo was emotionally exhausting’Mela Phulkari is aimed at reviving the art and bringing in a fresh whiff of all pretty and popular things from Punjab. It’s a platform where colourful pakhis (hand fans), madanis (butter churner) tilla jutis (footwear), manja (village cots), parandis (the festive hair accessory) are showcased. The  Mela was inaugurated by James David Bevan KCMG, British deputy high commissioner to India on 11 April and is slated to end on 24 April. So head on !last_img read more