Getting rid of the twin image that plagues holography

first_img Explore further Citation: Getting rid of the twin image that plagues holography (2007, June 19) retrieved 18 August 2019 from https://phys.org/news/2007-06-twin-image-plagues-holography.html “Holography is much better than just a photo,” explains Latychevskaia. “With a hologram, you can see the 3-D structure of the molecule. And, you can also see phase and absorption properties.” She goes on to point out that the ability to understand how molecules work would be a great aid in current fields of biology, especially in drug design. “Holography can provide greater insight, and the ability to see without this twin image obstructing the view is important.”Fink also sees the benefits of using holography for biological applications. “Right now we have powerful technologies, but they rely on crystallography,” he explains. “Many protein molecules have to be arranged in a crystal structure.” Additionally, he continues, “the high energy beams, like x-rays, used to study these molecules can damage them.”The key to the holography that Fink and Latychevskaia propose is using a low-energy electron beam. “This low energy is gentler on the molecule. We don’t have to accept damage to the molecules,” Fink says.Fink explains that an object, the molecule in question, is placed in front of the electron beam and the electrons are scattered. A detector sits about 10 centimeters from the object to bring about the electron holographic image by interference of the object wave with the reference wave. “We don’t use lenses,” Fink says. “The experiment is performed with coherent electron waves.”Latychevskaia says that part of the problem with the low-energy approach to holography was that, until now, there was no way to correct the twin image. “In early years, the solution was to separate the beams in two and the twin image would be at the side. An electron beam such as we use, though, can’t be separated. So the twin image obstructed the view of the molecule.” 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. For decades, since the ability to create a holographic record was discovered, a problem has plagued the field. “In holography,” Tatiana Latychevskaia tells PhysOrg.com, “a twin image unfortunately appears. It is seen out of focus so that, with small molecules, you would not be able to judge if what you are seeing is part of the molecule, or just the twin image.” Through a series of iterations and numerical aids in reconstruction, Latychevskaia found that the twin image could be removed, allowing for a hologram that allows the 3-D study of a molecule. Fink says that he has already submitted a timeline to the European Union for getting complete structural information from a single molecule by October 2009. “We hope to establish this as a tool for structural microbiology,” Fink enthuses. “With the twin image removal, a long-standing physics problem has now been solved.”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. Organic porous structures on 2-D defect networks Latychevskaia is a scientist at the University of Zurich, and she is part of an effort to make the holographic study of individual molecules practical. And, with a recent discovery of how to eliminate the twin image, Latychevskaia appears to be on her way. The experiment was done in the group of Hans-Werner Fink, also at the University of Zurich, and the findings are reported in “Solution to the Twin Image Problem in Holography,” published in Physical Review Letters. A tungsten tip is iteratively reconstructed as a hologram: (a) normalized hologram (b) conventional reconstruction yields reconstructed absorption and phase distributions (c) first iteration makes oscillations due to twin image apparent in these reconstructions (d) after the 500th iteration. Credit: Hans-Werner Fink, Reprinted with permission from Phys. Rev. Lett. Vol. 98, 233901 (2007). Copyright 2007 by the American Physical Society. (http://link.aps.org/abstract/PRL/v98/e233901)last_img read more

The Zabady A Waterproof MP3CDWMA Player

first_img The Waterproof Zabady audio player by Twinbird is a good idea for anyone on your gift list this year. The attractive Zabady is ideal for the kitchen, bathroom, by the sea, by the pool or any where a splash of water is present. The Zabady is not only splash-resistant, it boasts that it can be submerged in a little over 39 inches of water for one half-hour. Most users would not consider listening to music in three feet of water, but as most consumers know accidents around water do happen.The Zabady is functional and has the capability to play CDs from your collection or downloads from your MP3 and WMA files. The Zabady has a built-in USB port that allows the unit to play back songs from a connected drive with a capacity of 2GB. It has a FM radio tuner and is capable of seven hours of continuous play on its rechargeable battery. The MP3 and WMA is capable of 5.5 hours of play on the battery. The charge time for the battery for the CD player, according to the manufacturer Twinbird is six hours. In the box you will find the Zabady unit, an AC adapter, charge stand, battery pack, a 1 MHz antenna suction cup and leads. There is a manual and a pre-set tuner. The Zabady comes in white, but the manufacturer indicates it may be available in silver. The cost is under consideration, but will probably sell in the range of $180 to $190.An aesthetic feature of the Zabady is the LED display. The LED lights up while the unit is charging and the light goes out when it is fully charged. The display also indicates the name of the artist, album and tune name when a CD is played. The Zabady weighs less than 32 ounces and is about the size of a flour cannister.The Zabady automatic turn off function can be set to cut off the power source after the desired play time is met. This saves battery life and the necessity for frequent recharging. The charge stand cradle is convenient and when Zabady is not in use is a good place to set the unit. The Zabady will only take 4 hours of recharging for the radio, MP3 and WMA player. Currently the Zabady is available only in Japan. Inquiries for orders may be made through the Twinbird web site. 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. Twinbird’s Zabady audio player. Credit: Twinbird The Zabady manufactured by Twinbird is a waterproof audio player capable of playing CDs, MP3, WMA and FM radio. The Zabady has a built in USB port with 2GB of memory. The LED dispay shows the artist, name of the album and song being played. Citation: The Zabady: A Waterproof MP3/CD/WMA Player (2007, November 29) retrieved 18 August 2019 from https://phys.org/news/2007-11-zabady-waterproof-mp3cdwma-player.htmllast_img read more

Researchers develop a worldwide tourism network

first_img Citation: Researchers develop a worldwide tourism network (2008, June 11) retrieved 18 August 2019 from https://phys.org/news/2008-06-worldwide-tourism-network.html Explore further It wasn’t too long ago in human history that people rarely, if ever, traveled beyond the village they were born in. We’ve come a long way since then: according to the World Tourism Organization (WTO), international traveler arrivals peaked at 763 million in 209 countries and territories in 2004. The WTO expects that number to reach 1.6 billion by 2020, making international travel one of the fastest growing economic sectors. Map of the world tourism network, with link color corresponding to the intensity of the connection. Top countries receiving tourists: US, Canada, China, Russian Federation. Top countries sending tourists: US, UK, Germany, France. Top countries receiving and sending: US, Canada, Australia, China, Russian Federation. Countries receiving and sending the fewest tourists were the South Pacific islands. Credit: Miguéns and Mendes. But where do all these people go? And where do they come from? Further, what is the relationship among countries that are popular or unpopular tourist destinations? Mathematician Joana Miguéns and physicist José Mendes, both from Aveiro University in Portugal, have developed a worldwide tourism network to help investigate some of these questions. Besides revealing information on human traveling patterns, the network will also likely help researchers understand information transfer and global wealth flows, since tourism accounts for more than 10% of the world’s gross domestic product.Miguéns and Mendes used 2004 data from the WTO, which defines tourism as “the activities of persons traveling to and staying in places outside their usual environment for not more than one consecutive year for leisure, business, and other purposes.” In the researchers’ model, links between countries represent tourist arrivals from one country to another. The network is both directed and weighted – directed in that the links are one-way, and weighted in that links become stronger as the number of traveler arrivals increases. In their analysis, the researchers found that the network is very strongly directed. Specifically, if one country has tourists visiting from another country, there is only a 25% probability that the second country will have tourists visiting from the first country. And, despite the large numbers of travelers, the overall connectivity of the network is lower than might be expected. A full 60% of all pairs of countries are not connected to each other, meaning they don’t exchange tourists at all.Another interesting feature of the world tourism network is that, in at least one way, it behaves more like an economic network rather than a social network. In the tourist network, countries with a high degree (those that are popular tourist destinations) are more likely to be neighbors with countries with a low degree (less popular tourist destinations). This behavior is similar to economic and transportation networks, which have patterns where popular central hubs have many inbound connections from peripheral nodes. As the researchers note, this finding could question the common notion of culture as the driving force of tourism.center_img How climate change impacts the economy “In general, social networks are of an assortative type, where hubs connect to hubs,” Miguéns told PhysOrg.com. “Here we observe a different structural topology, with disassortative behaviour, more characteristic of technologic and economic networks, where hubs connect with small-degree nodes. More recent results also show that, on the level of clustering coefficients, the same characteristic behaviors of nonsocial patterns are observed.”The researchers also found that, overall, the world tourism network is scale-free over four orders of magnitude. The network changes in scale, but not in relation, even as the number of travelers dramatically increases or decreases. So as travelers increase, as expected, it’s the countries that are already the popular tourist destinations that are more likely to add new connections. This scale-free nature, which contrasts with the random topology expected of heterogeneous networks, opens up an entirely new class of networks. “Contrarily to the results obtained recently for the worldwide air network (where a scale-free network was observed), the results for the tourism network are – from the point of view of degree of different countries – similar to a random network,” Miguéns said. “A scale-free network is obtained when we have in consideration the traffic weight between countries. The way to understand the concept of preferential attachment seems from our point of view related with a kind of ‘social phenomenon’: marketing, travel promotion, word-by-mouth, etc.”More information: Miguéns, J. I. L. and Mendes, J. F. F. “Travel and Tourism: into a Complex Network.” Physica A, Volume 387, Issue 12, 1 May 2008, Pages 2963-2971. Also available at: arXiv:0805.4490v1. 29 May 2008.Copyright 2008 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. 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

Patent Nintendos Wii Football Controller

first_img(PhysOrg.com) — Nintendo has come up with yet another idea for an accessory to add to its list of Wii peripherals. This time it’s a soft football-shaped controller that is said to simulate the feel and touch of a real ball when playing football simulation games such as the NFL game, Madden. New World Cup football will unsettle goalkeepers, predicts scientist The football controller holds the Wii remote and another slot holds the nunchuk, which increases the sensitivity of the football. The device also has support for Wii Motion Plus, to improve the controller’s recognition of movements, detect orientation and improve its accuracy.At this stage, the football controller is only at the patent application stage and may not make it to the retail stores, but since there’s already a Wii bowling ball and similar controllers, it may well become available in the near future.More information: European Patent Office, Method and apparatus for simulating games involting a ballvia Siliconera© 2009 PhysOrg.com The football controller is designed to simulate movements during football games, such as running, jumping and throwing. The football is moved quickly from side to side to dodge opponents, and raising the ball simulates a jump. Making jogging motions with the ball is supposed to determine the running speed. Other options are available on the Wii remote, which fits into a slot on the ball. The football also simulates throwing, of course. The player grasps the ball and makes a throwing movement. The direction and power of the throw in the game are determined by the power, angle, force and pitch of the throwing motion. Fortunately, the football has a strap, which should (with any luck) stop players throwing the ball at the TV screen! Explore furthercenter_img Citation: Patent: Nintendo’s Wii Football Controller (2009, September 2) retrieved 18 August 2019 from https://phys.org/news/2009-09-patent-nintendo-wii-football.html A patent application for the football controller was lodged recently by the Vice President of Research and Development for Nintendo of America, Howard Cheng. The patent has been filed but not yet approved. The device is certainly not in production, and since it is only a patent application, it may never be manufactured. 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

Google QR codes to appear in a store window near you w

first_imgIn the U.S. smart phone users will first have to download and install an appropriate QR code reader. When the QR code is scanned, they will then have to give a number of permissions before the information is displayed, and this slows the process down from a single-click in Japan to a 45-second procedure in the U.S.Google is also introducing the sharing of business coupons via QR codes. When the code is scanned the smart phone will display a coupon or voucher that can be redeemed in the store from the image on the screen.The QR code system allows Google to advertise to people who are not at their computers, and advertisers have the benefit of knowing that the people being reached are in a position to use their services.Google expects the QR code system to work effectively with the iPhone, BlackBerry, and Android, but says it should work with many other smart phones as well.More information: Favorite Places on Google© 2009 PhysOrg.com Travel book goes mobile with scannable QR code (PhysOrg.com) — Google recently sent out 100,000 stickers to selected US businesses for use on their storefront windows. The stickers have the Google Maps logo and a QR code that can be scanned by smart phone cameras and display Google listings for the business on the phone screen. 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: Google QR codes to appear in a store window near you (w/ Video) (2009, December 8) retrieved 18 August 2019 from https://phys.org/news/2009-12-google-qr-codes-window-video.html A QR (Quick Reference) code is a variation of a barcode, having a pixilated rectangular image rather than a series of stripes. QR codes first appeared in 1994.The businesses chosen by Google are designated “Favorite Places” and were selected on the basis of the number of searches made for the business on Google Maps. If the business chooses to stick the decal on their store window, smart phone users can scan the QR code using the phone’s camera, and Google listings about the place are displayed. The listings can include information such as reviews, details of opening times, contact information, prices, links to the website, and so on. QR codes have been widely used in Asia for some times, and in places such as Japan the QR code readers are built in to smart phones. In Japan QR codes appear on items such as food packaging, restaurants, bus stops, and real estate agents’ windows. When the codes are scanned, additional appropriate information is displayed on the smart phone, such as suggested recipes, calories and nutritional information, menus, bus timetables, and floor plans for real estate for sale.last_img read more

Ninjabot strikes with force of a mantis shrimp

first_img(Left) In Ninjabot, a hand crank (hc) is used to rotate a loader (lr) clockwise, which causes the appendage holder (ah) to rotate counterclockwise. This causes the beam spring (bs) to deflect while also rotating the appendage (a) into the pre-loaded position. (Center) To release Ninjabot’s appendage, the loader slides past the end of the appendage holder to release the stored energy in the beam spring, exerting a torque on the appendage holder and causing the appendage to rapidly rotate clockwise. (Right) Screenshot of O. scyllarus using a similar spring-loading mechanism to smash a snail shell from the video below. Credit: S. M. Cox, et al. © 2014 IOP Publishing Ltd Powerful little shrimpImitating a mantis shrimp’s appendages is a complicated endeavor for many reasons, with the most obvious being the appendages’ extreme speed. Previous research has shown that the shrimp’s fast movement causes cavitation, which is the formation of bubbles due to a quick drop in pressure. When these bubbles move to areas of higher pressure, they quickly collapse to form shock waves that are so powerful that they can break open mollusk shells and erode holes in nearby metal, such as boat hulls. The heat produced by these shock waves equals the temperature at the surface of the sun (over 5000 K).As the scientists note in their study, mantis shrimp are not the only animals that harness the intense forces of cavitation bubbles. For example, whales can create cavitation bubbles by flapping their tails, stunning large schools of fish. Fungal spores and some insects also rely on cavitation for different purposes.In this study, the researchers for the first time measured the strike velocity (30 m/s) and acceleration (1.5 x 105 m/s2) of the mantis shrimp Gonodactylus smithii, which they caught off the coast of Australia. These values are the highest reported to date for any species of mantis shrimp. For comparison, this acceleration is only somewhat lower than the average acceleration of a bullet in the muzzle of a gun (4.4 x 105 m/s2), although a bullet has significantly faster velocity (around 400 m/s). Although many human inventions can achieve accelerations in the mantis shrimp’s range, they usually require explosive materials, like in a gun or an engine. In contrast, mantis shrimp use a spring-like mechanism that is tightened and then released to generate acceleration. No explosives required Although mantis shrimp have captured the public’s fascination with their ability to strike and kill their prey with stunning force, the underlying mechanisms involved in the high-speed strike are not fully understood by scientists. So a team of researchers, S. M. Cox, et al., from the University of Massachusetts, Amherst, has designed and built a robot, called Ninjabot, that imitates the mantis shrimp’s strike and may help reveal the kinematics behind the powerful maneuver. Play An example of the cavitation seen with Ninjabot before impact using a cylindrical appendage run at speeds comparable to those achieved by O. scyllarus. Credit: S. M. Cox, et al. “One question recurred throughout Ninjabot’s development: what could we hope to learn from a model that was not a perfect replica of the mantis shrimp? Picasso once said, ‘We all know that Art is not truth. Art is a lie that makes us realize truth.’ Building a model is like constructing a work of art, with only certain aspects actually mimicking reality. And often it is only through contrasting something that is close, but not identical, to the world that we come to notice details that were otherwise hidden. By changing one property at a time while holding others constant, Ninjabot could make apparent the effects of individual properties on ultrafast movements in a way that was difficult or impossible with natural variation alone. Systematic exploration is often useful when nature’s response to design constraints are different enough from human solutions that our failure of imagination makes them difficult to discern.” PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen Play A simplified visualization of the mechanism of Ninajbot. Credit: S. M. Cox, et al. Despite Ninjabot’s record-breaking acceleration performance, it still has several physical limitations that prevent it from behaving exactly like its biological counterpart. For example, Ninjabot consists of 9 kg of steel, while one of G. smithii’s appendages is only about 0.4 g. In addition to weight and material differences, the robot’s components are also of different shapes and sizes than those of the animal. The researchers view these differences as a testimony to the efficiency of biological design, as well as an indicator of the crucial role that materials play in any biomimetic system.With the robot’s limitations in mind, the researchers reflected upon the advantages and disadvantages of building a robot to study animal behavior compared to developing theoretical models to do the same. One advantage of performing tests on a physical robot, they note, is that while mathematical models risk simplifications that may miss key relevant performance parameters, “physical models cannot break the laws of physics.””Mathematical models are only as good as our knowledge of the underlying physics and our ability to implement that understanding numerically,” they succinctly wrote.Still, the researchers acknowledged, in a very eloquent way, that Ninjabot’s imperfections caused them question its usefulness and recall the purpose of creating physical models: PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen Journal information: Bioinspiration and Biomimetics Citation: Ninjabot strikes with force of a mantis shrimp (2014, February 28) retrieved 18 August 2019 from https://phys.org/news/2014-02-ninjabot-mantis-shrimp.html © 2014 Phys.org. All rights reserved. In experiments, Ninjabot achieved a maximum velocity (25.9 m/s) and peak acceleration (3.2 x 104 m/s2). Although these values are less than those of G. smithii, they closely match those of the second-fastest mantis shrimp species, Odontodactylus scyllarus (21 m/s, 10 x 104 m/s2). Before this study, O. scyllarus had the fastest known strike of any mantis shrimp.To the researcher’s knowledge, Ninjabot’s peak acceleration exceeds that of any biomimetic robot published to date, with the previous highest value belonging to a flea-inspired jumping robot (2 x 103 m/s2). “This study shows just how difficult it is to achieve these sorts of accelerations in water,” coauthor Suzanne Cox, a graduate student at the University of Massachusetts, told Phys.org. “What the mantis shrimp are doing is astounding. The design principles that we learned in the process of building Ninjabot could be useful to anyone interested in generating super-high accelerations without explosives: store the energy in a big spring and use it to power something tiny.” Models imitating realityBy studying the Ninjabot with high-speed cameras, and controlling its parameters, the researchers also gained new insight into the kinematics of the mantis shrimp. One important finding was that the Ninjabot’s velocity is the single most influential parameter on the formation of cavitation bubbles. Nevertheless, the bubbles still regularly form at velocities well below predictions and often fail to form at velocities well above predictions, indicating that stochastic components heavily influence the formation of these bubbles. The researchers hope that further experiments will shed more light on the formation of cavitation bubbles, in particular the mystery of how mantis shrimp manage to prevent bubble formation during non-impact strikes, allowing them to avoid self-injury. More information: S. M. Cox, et al. “A physical model of the extreme mantis shrimp strike: kinematics and cavitation of Ninjabot.” Bioinspiration & Biomimetics. DOI: 10.1088/1748-3182/9/1/016014 Play O. scyllarus smashing a snail shell. Credit: S. M. Cox, et al. To mimic the mantis shrimp’s striking appendage as closely as possible, the researchers designed Ninjabot to also use a spring to achieve high acceleration. While a mantis shrimp uses muscle to load the spring and a latch to release the stored elastic potential energy, the Ninjabot uses a crank system for loading and slides the loader away for release. In both cases, the release of the spring causes an appendage to rotate forward with extreme velocity. The researchers compare the mechanism to pushing on a door, since pushing close to the door’s hinges requires little movement while the part of the door closer to the door knob experiences a much larger rotational motion. PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen Explore further Study finds mantis shrimp process vision differently than other organisms (w/ video) 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

Scientists call for more eyes in the sky amidst alarming climate change

first_img Journal information: Proceedings of the National Academy of Sciences Explore further © 2018 Phys.org Citation: Scientists call for more eyes in the sky amidst alarming climate change (2018, August 9) retrieved 18 August 2019 from https://phys.org/news/2018-08-scientists-eyes-sky-alarming-climate.html Feedback processes include the release of methane from Arctic ices melted by high ocean temperatures, reduction of North American snow cover and Amazon rainforest dieback. These processes compound the inherent difficulty of studying the climate on a global scale, and substantial disagreements exist between models that attempt to predict the future of climate change.Now, in an epic-scale Perspective column in the Proceedings of the National Academy of Sciences, researchers from Goddard Space Flight Center, the Jet Propulsion Laboratory and the University of Oklahoma describe the difficulties of teasing apart carbon cycle feedbacks, and how satellite observations are already making a significant contribution to resolving these uncertainties. Regarding carbon cycle-climate feedbacks, the authors write, “If these feedbacks change with changing climate, which is likely, then the effect of the human enterprise on climate will change.” In other words, climate feedback mechanisms alter the climate, which in turn affects the incidence and severity of feedbacks. “The current uncertainty of flux estimates of (the perturbation due to fossil fuel emission) is evidenced, in part, by disagreements between top-down derived flux estimates and bottom-up inventory methods,” they write.The paper is a catalog of the intimidating uncertainties climate scientists are confronting as they try to bring a holistic picture of climate trends into focus, including carbon and methane cycling. For instance, the authors observe that ocean models largely agree about global carbon inventories—25 percent of anthropogenic carbon is believed to be sequestered in the oceans—but the fact that there is no consensus about the specific regions responsible calls into question this seeming agreement.The authors are emphatic about the utility of satellite observations for resolving such uncertainties. Satellites can observe column CO2 emissions, even in areas of the world with poor reporting resources, which is key to understanding carbon cycling mechanisms in the tropics. A lack of current reporting from such regions greatly inhibits climate modeling, and existing models have greatly divergent conclusions as a result.Satellites can also measure net fluxes in emissions by their correlation with solar-induced fluorescence (SIF) in the atmosphere. By sampling the oxygen-A band, satellites can determine the optical path length through the atmosphere. SIF is directly related to photosynthesis, so these observations provide measurements of net flux as well as gross fluxes. Finally, the authors cite the long track records of satellites monitoring carbon monoxide produced by the burning of fossil fuels and biomass. Using a combination of these observation and measurement techniques, researchers could reduce uncertainties about climate feedbacks, tease apart the relationships between feedback mechanisms and anthropogenic carbon emissions, and raise the resolution and accuracy of their climate models. This is especially important as climate impacts of atmospheric carbon and methane are becoming alarmingly evident in weather patterns. Planet now at risk of heading toward ‘hothouse Earth’ statecenter_img In the midst of a record-breaking global heat wave, a recent international study presented a terrifying worst-case scenario: that “hothouse Earth” conditions are likely to prevail even if the world meets the carbon reduction levels of the Paris Agreement. Lead author Will Steffen from the Australian National University and Stockholm Resilience Centre said, “Human emissions of greenhouse gas are not the sole determinant of temperature on Earth. Our study suggests that human-induced global warming of 2°C may trigger other Earth system processes, often called ‘feedbacks,’ that can drive further warming – even if we stop emitting greenhouse gases.” More information: Observing carbon cycle–climate feedbacks from space. Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1716613115AbstractThe impact of human emissions of carbon dioxide and methane on climate is an accepted central concern for current society. It is increasingly evident that atmospheric concentrations of carbon dioxide and methane are not simply a function of emissions but that there are myriad feedbacks forced by changes in climate that affect atmospheric concentrations. If these feedbacks change with changing climate, which is likely, then the effect of the human enterprise on climate will change. Quantifying, understanding, and articulating the feedbacks within the carbon–climate system at the process level are crucial if we are to employ Earth system models to inform effective mitigation regimes that would lead to a stable climate. Recent advances using space-based, more highly resolved measurements of carbon exchange and its component processes—photosynthesis, respiration, and biomass burning—suggest that remote sensing can add key spatial and process resolution to the existing in situ systems needed to provide enhanced understanding and advancements in Earth system models. Information about emissions and feedbacks from a long-term carbon–climate observing system is essential to better stewardship of the planet. Credit: CC0 Public Domain 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

Biophotonics In situ printing liquid superlenses to image butterfly wings and nanobiostructures

first_img In situ printing glycerol superlenses for nanoscale imaging of butterfly wings. a) Illustration of the printing process and a microscopic view of the formed superlens array on the wing scales. b) Conceptual image of the direct nanoscale observation of butterfly wing scales via superlenses, and the magnified image obtained through the superlens indicating a resolution of features with sizes less than 1 µm on the wing scale. Credit: Microsystems & Nanoengineering, doi: https://doi.org/10.1038/s41378-018-0040-3 In a new method, materials scientists Boliang Jia and colleagues at the departments of mechanical engineering and robotics presented a printable biocompatible superlens placed directly on objects of interest to observe subdiffraction-limited features (resolution beyond the diffraction limit). They then viewed the natural features using an optical microscope to demonstrate nanoscale imaging of butterfly wings in color. The study allowed super-resolution imaging and a larger field of view (FOV) compared to the previous dielectric microsphere-based optical systems of super-resolution microscopy. The new approach created a fast and flexible path to observe the direct colors of biological features at the nanoscale in the visible range. The results are now published in Microsystems and Nanoengineering, where the work allowed optical measurements at the subdiffraction-limited scale. A superlens is based on an optical material with a negative index of refraction (optical metamaterials) that could experimentally reverse nearly all known optical phenomena. Technically, a thin negative-index film can function as a ‘superlens’ to provide image detail with a resolution beyond the diffraction limit to which all positive-index lenses are subjected to. (1) Characterization of printed glycerol superlenses with different numbers of drops/lens. a–e) Lateral images of glycerol lenses with 1, 5, 10, 30, and 60 drops/lens on a clean silicon wafer. f) The jetting waveform used in the experiment. g) Plots of lens height (blue cross), diameter (orange star), and H/D ratio (black circle) with respect to the number of drops/lens. h) An on-chip printed glycerol superlens array (50 vol%, 50 drops/lens) observed via a 4× (NA 0.10) objective at a 45° angle-of-view using a Nikon, Ti-E microscope (left). The table (right) shows the dimension statistics. Scale bar: a–e 20 µm, h 100 µm. (2) Configurations of the experimental setup a) Schematic of the imaging system based on the Nikon Ni-E platform without the use of a superlens. The major components include an Andor Zlya 5.5 sCOMS camera with a motorized focusing stage (Z), an Intensilight mercury-fiber illuminator (C-LHGFIE), a filter cube, an objective, and a motorized sample stage (XY). b) The configuration with a BTG microsphere (top) and the optical images of two BTG microspheres, BTG-A (middle) and BTG-B (bottom), mounted on a microprobe (5 μm tip diameter) with NOA63 (Norland) adhesive. c) The configuration with a printed glycerol superlens (top) and the optical images of two lenses printed at location-I (middle) and location-II (bottom) of the CPU samples. Credit: Microsystems & Nanoengineering, doi: https://doi.org/10.1038/s41378-018-0040-3 , Nano Letters Nanostructures and natural patterns have long fascinated researchers in bioinspired materials engineering. Biological samples can be imaged and observed at the nanoscale using sophisticated analytical tools in materials science, including scanning electron microscopy (SEM) and transmission electron microscopy (TEM). While imaging methods contribute to the understanding of structures by revealing material properties for biomimetic materials synthesis, they have often done so with the loss of photonic properties inherent to the materials. The butterfly wings of Morpho cypris were first observed via high-resolution SEM in 1942, which led to the discovery of detailed structures below the diffraction limit using sophisticated tools. Since then, Morpho butterflies have been a subject of interest in bioinspired materials research due to their iridescent color and distinct photonic properties. For decades, the properties of light interference resulting from their brilliant nanostructures have attracted great interest in nanophotonics and biomimetic materials research. However, direct optical observations of the subdiffraction-limited structure of the wings at the nanoscale yet remain to be reported. More information: Boliang Jia et al. In situ printing of liquid superlenses for subdiffraction-limited color imaging of nanobiostructures in nature, Microsystems & Nanoengineering (2019). DOI: 10.1038/s41378-018-0040-3 Thomas F. Anderson et al. An Electron Microscope Study of Some Structural Colors of Insects, Journal of Applied Physics (2005). DOI: 10.1063/1.1714827 Jingyun Huang et al. Controlled Replication of Butterfly Wings for Achieving Tunable Photonic Properties, Nano Letters (2006). DOI: 10.1021/nl061851t Radwanul Hasan Siddique et al. Theoretical and experimental analysis of the structural pattern responsible for the iridescence of Morpho butterflies, Optics Express (2013). DOI: 10.1364/OE.21.014351 Pete Vukusic et al. Erratum: Photonic structures in biology, Nature (2003). DOI: 10.1038/nature01941 In the study, Jia et al. devised a method to print glycerol (transparent liquid) on to butterfly wings and observe nanoscale wing structures hitherto unobserved via conventional optical microscopes. The work will pave the way for advanced liquid superlenses coupled with fast and flexible methods in optics. The results will assist nanostructural inspection via biophotonics in biological and non-biological samples. Citation: Biophotonics: In situ printing liquid superlenses to image butterfly wings and nanobiostructures (2019, January 31) retrieved 18 August 2019 from https://phys.org/news/2019-01-biophotonics-situ-liquid-superlenses-image.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. (1) Comparison of images of the M. m. menelaus ventral wing scales. Color images a and f were taken from the eyepiece using an iPhone 7 Plus camera. Grayscale images b–d and g–i were taken with an Andor Zyla5.5 sCMOS camera. Images e and j were taken by SEM; a–e are images of ground scales; f–j are images of cover scales; and c and h are the enlarged images of the red square areas in b and g, respectively. Yellow brackets indicate one of the lamellae tips on the ridges. All optical images were taken under a 100× (NA 0.90) objective. (2) Analysis with color images of sub-diffraction-limited structures. Ground scales of M. m. menelaus. a-d) were taken from the eyepiece using an iPhone 7 Plus camera without and via the glycerol superlens. Line profiles over the red dashed lines in a–e are shown in f and g. The ridges marked by yellow arrows were enlarged and are shown in the lower right. The inverted yellow rectangles mark the identified lamella tips along each enlarged section of the ridges. For ridges Ra and Rc imaged without the superlens, no lamella tips could be distinguished. The labels “La–e” correspond to line profiles, and labels “Ra–e” correspond to the enlarged ridges. Scale bar: 2 μm. OM optical microscopy, SL superlens, SEM scanning electron microscopy. Credit: Microsystems & Nanoengineering, doi: https://doi.org/10.1038/s41378-018-0040-3 , Optics Expresscenter_img Experimentally acquired images at location-I on the CPU sample. a–d) Optical images taken via BTG-A (a), BTG-B (b), Gly-I (c), and without a superlens (d). The objective used was 100× (NA 0.90). The estimated fields-of-view (FOVs) in a, b, and c are 4.7, 2.9, and 7.5 μm in diameter, respectively. e) The SEM image over the same area. f–j) Enlarged images over an approximate area of 3.9 μm × 2.7 μm from the center of a–e, respectively. The yellow arrows point to an “H”-like pattern approximately 120 nm in width. k–o) Bandpass-filtered images of f–j, respectively. The scale bar in f–o: 500 nm. p) Profiles of the red lines in k–o with normalized intensity. The 1700-nm line profiles are aligned with the features in the SEM image above. Credit: Microsystems & Nanoengineering, doi: https://doi.org/10.1038/s41378-018-0040-3 High-refractive-index microspheres in aqueous media have attracted great interest in recent years for observing liquid-immersed biological samples such as biological cells in vivo. Yet, the method is not favorable for samples with high-refractive index in dry conditions. In the present work, Jia et al. presented an in situ printed biocompatible glycerol superlens (SL) with higher resolution and larger FOV than barium titanate glass (BTG) microspheres under dry conditions. The scientists chose glycerol since it is a transparent liquid with a relatively high refractive index that is capable of printable droplet formation across a wide size range. As an important feature, glycerol contains strong inter-molecular interactions and is therefore highly resistant to evaporation. Although microdroplets of water typically evaporate almost instantly, by comparison, glycerol printed as droplets with a volume of 50 percent could exist at least for a day on substrates without significant size changes. Jia et al. therefore directly printed glycerol superlenses on a Morpho butterfly wing using an ink-jet printing machine. Thereafter, they characterized the glycerol images using a central processing unit (CPU)-integrated circuit (IC). The scientists observed nanobiostructures ranging from 50 nm to 200 nm in scale. In the work, the scientists adjusted the viscosity of the glycerol solution via dilution tests with MiliQ water to select an optimal concentration of 50 volume percent (50 vol%) for printing. Explore further In their work, Jia et al. observed two types of butterflies: Morpho Menelaus and Agrias beatifica beata. The scientists printed 60 glycerol drops (or lenses) on the butterfly samples to obtain spherical lenses approximating 95 µm in diameter. They observed the wing-scale features via an upright microscope system. The scientists were able to capture the ventral wing scales of the butterflies, where the Morpho species displayed two types of wing scales; ground and cover scales. In comparison to SEM, glycerol superlenses were unable to resolve complete structures entirely, but they showed the existence of substructures between the ridges of butterfly wings. For example, Jia et al. showed that in situ glycerol superlenses could extend the limit for nanoscale structures in biological samples to approximate 200 nm in width. Additional experiments showed the ability to color-image subdiffraction-limited nanobiostructures using the superlenses. The new method offers a cost-effective, fast and high-resolution imaging technique to visualize subdiffraction-limited nanobiostructures in situ. The work paves the way for water-immiscible liquids with high refractive indices to print liquid superlenses for water-immersion-based imaging applications. Biocompatible liquids such as silicone oil can be explored as superlenses underwater via low cost ink-jet printing next. Materials scientists continue to work toward engineering advanced liquid superlenses in nanobiophotonics. The scheme introduced by Jia et al. provides a fast and easy-to-implement strategy to observe nanobiostructures in biological and nonbiological samples. Schematic of the subdiffraction-limited imaging of a butterfly sample using in situ printed glycerol superlenses. The Morpho menelaus menelaus (M. m. menelaus) and Agrias beatifica beata (A. b. beata) samples were placed flat on a clean glass slide for printing. The microscopic images show the scale arrangement of the ventral wing of M. m. menelaus (bottom left) and the superlens array printed on the wing scales (middle). The superlenses exhibited a sphere-like geometry on the wing scales. The lateral image (upper right) was acquired using the inverted microscope (Nikon, Ti-E). The dimension statistics include data from 13 measured lenses based on their lateral images. Credit: Microsystems & Nanoengineering, doi: https://doi.org/10.1038/s41378-018-0040-3 , Nature In optics, solid immersion lenses (SILs) can enhance optical resolution by increasing the effective numerical aperture (NA) of the imaging medium. The droplet lens is considered a liquid version of SILs with a flawless surface. The scientists first characterized the printed glycerol superlenses in the study using a different number of drops per lens on a clean silicon wafer before administration on butterfly wings. They selected the ideal number of drops per lens after a few trials; the resulting diameters of the glycerol lenses were comparable to BTG microspheres. Thereafter, they compared configurations of the experimental setup for the BTG microspheres and the glycerol superlens. The work showed that large BTG microspheres provided a large FOV, while a higher resolution was obtained with smaller BTG microspheres. When the scientists compared the images obtained with glycerol superlenses and those obtained using BTG, the results significantly improved in uniformity for images obtained using glycerol superlenses, alongside sharper nanoscale features. This implied that printed glycerol superlenses offered superior resolution capacity compared to BTG microspheres of equal and smaller sizes in air. Method that boosts contrast of high-resolution optical images has potential to enable lithography at the nanoscale Journal information: Journal of Applied Physics © 2019 Science X Networklast_img read more

FIRST J1419189394036 is an orphan long gammaray burst study finds

first_imgImages of FIRST J1419+3940 at 1.6 GHz with the EVN on September 18, 2018 derived from the two gain calibrations performed in Tianma (original, top, and scaled, bottom). Credit: Marcote et al., 2019. Using a network of radio telescopes, European astronomers have investigated a decade-long transient known as FIRST J141918.9+394036. Results of this study, presented in a paper published February 18 on arXiv.org, provide important insights into the nature of this mysterious source, confirming that it is an “orphan” long gamma-ray burst. © 2019 Science X Network VLA sky survey reveals first ‘orphan’ gamma ray burst Explore further FIRST J141918.9+394036 (or FIRST J1419+3940 for short) is a slowly evolving, extragalactic radio transient. It has decayed in brightness over the last few decades. Recent observations of this object have revealed that it could be an afterglow of a powerful gamma ray burst (GRB) that produced no gamma rays detectable on Earth. FIRST J1419+3940 was therefore classified as the first known “orphan” GRB.However, the fading radio emission from FIRST J1419+3940 could also be interpreted as coming from a new-born nebula powered by a young magnetar. Given that this transient shares similar properties and host galaxy type to the radio source associated with the first known fast radio burst (FRB), FRB 12102, some astronomers assume that FIRST J1419+3940 is a young, rapidly spinning magnetar.In order to verify which of the two hypotheses is true, a team of astronomers led by Benito Marcote of Joint Institute for VLBI ERIC in the Netherlands, has employed the European VLBI (very-long-baseline interferometry) Network to conduct radio observations of FIRST J1419+3940.”To distinguish between these hypotheses, we conducted radio observations using the European VLBI Network at 1.6 GHz to resolve the emission spatially and to search for millisecond-duration radio bursts,” the astronomers wrote in the paper.In result, Marcote’s team found that FIRST J1419+3940 is a compact radio source with a flux density at a level of 620 µJy. With a luminosity distance of about 283 million light years, the size of the source was estimated to be approximately 5.2 light years. Moreover, the observations detected no millisecond-duration bursts of astrophysical origin from this object and confirmed that the radio emission from it is non-thermal.According to the paper, the properties of FIRST J1419+3940 and lack of short-duration bursts from it are consistent with jet expansion from a putative “orphan” long GRB. The researchers noted that although this object shows similar properties as the persistent source associated with FRB 121102, it exhibits significant differences such as much faster expansion and stronger luminosity decay. This disfavors the magnetar birth nebula theory.”A flux density lower than expected is reported, suggesting a faster decline after 2015. This decay could be explained by a change in the post-shock microphysical parameters following the transition to the non-relativistic phase, or by a drop in the ISM [interstellar medium] density (e.g. due to the shock reaching the outer edge of the star-forming region where the GRB exploded),” the paper reads.Although the study confirms the RGB status of FIRST J1419+3940, the researchers noted that it could be still a site of potential FRB production. To verify this, future observations of this source at higher radio frequencies are required. More information: B. Marcote et al. Resolving the decades-long transient FIRST J141918.9+394036: an orphan long gamma-ray burst or a young magnetar nebula? arXiv:1902.06731 [astro-ph.HE]. arxiv.org/abs/1902.06731 Citation: FIRST J141918.9+394036 is an ‘orphan’ long gamma-ray burst, study finds (2019, March 4) retrieved 18 August 2019 from https://phys.org/news/2019-03-j1419189394036-orphan-gamma-ray.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

Caravans Taking on the roads less travelled

first_imgSwirling through the winding hills of Tuscany on a road trip, heave a sigh of pleasure as you take in the picturesque landscapes. It is right out of an advert from European tourism industry that gets them returns on their natural resources. It’s just not the fast and convenient Eurorail but the road transport and tourism that entices tourists. While the advent of road tourism kickstarted the concept of caravan tourism around the globe; in India only Madhya Pradesh capitalized on its road transport and tourists. Untapping India’s potential for tourism on road , PHD Chamber organised a curtain raiser on caravan tourism- India by road.For caravan tourism in India, its a shout out to the tourism agencies to liason with state road network and local government agencies to facilitate the major tourism road projects in the country.  Although the road sector in India has been declared as an industry, it is still on a slow trail.last_img read more