Engineers design selfstabilizing electric bicycle

first_img“Because the posture response of the bicycle is passive, it is not possible to control directly,” Murakami explained. “Therefore, it is necessary to do the stabilization control indirectly by using the bicycle steering control. This is one reason why bicycle stabilization becomes difficult.”While the optimal stabilization strategy allowed the bicycle to run on a straight path on the rollers, the other strategies could stabilize the bike’s posture, but had position errors that resulted in the bicycle diverging from its straight path. One key to achieving these results was developing a simplified dynamic model for a bicycle, a modification of the more complicated but widely studied Sharp dynamic model developed by R. S. Sharp in 1971. The researchers’ simplified version enabled them to develop a bicycle controller that fused stability and trajectory control. While these experiments tested the bicycle’s ability to ride in a straight line, the researchers predict that the control strategy could also extend to curved trajectories. The team plans to make improvements to the model to account for road irregularities and tire characteristics, which weren’t accounted for in this study. By confirming the feasibility of bicycle stability unassisted by a human rider, the researchers hope to continue making bicycles increasingly sophisticated and safe.“Our final goal is to stabilize the bicycle at zero speed,” Murakami said. “Many bicycle falling accidents happen when elderly people stop a bicycle in a crosswalk, and so on.”More information: Tanaka, Yasuhito, and Murakami, Toshiyuki. “A Study on Straight Line Tracking and Posture Control in Electric Bicycle.” IEEE Transaction on Industrial Electronics. To be published.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 This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.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. Despite the challenge, engineers from Keio University in Yokohama, Japan, are developing a self-stabilizing electric bicycle, one that can stay upright by itself while being propelled and steered by electric motors. Their ultimate goal is to create a sophisticated, high-performance bicycle that could serve as a convenient alternative to a small car.Yasuhito Tanaka and Toshiyuki Murakami, both with the Department of System Design Engineering at Keio University, will publish their study in an upcoming issue of IEEE Transactions on Industrial Electronics.“The bicycle is a comfortable vehicle that is safe and can offer more familiarity with nature compared with the car,” Murakami told PhysOrg.com. “Especially, the bicycle is a convenient vehicle that can be useful as an activity for elderly people. However, it is thought that a lot of bicycle falling accidents occur with elderly people, and it is very useful to achieve a safer bicycle.”As the first step toward their goal, the researchers designed an electric bicycle that maintains its balance and follows a straight path. In simulations and experiments, they tested three different strategies that combine stability control and trajectory control. The researchers found that a combination of the “posture controller” (for stability) and “steering function controller” (for trajectory) could enable the bicycle to drive by itself continuously. In the experimental set-up, a conventional bicycle was placed on three rollers – two underneath the rear wheel and one underneath the front wheel. When the rear rollers rotated, the front roller rotated through a wire. Two motors controlled the motion of the bicycle – the motor on the handlebars controlled steering, and the motor in the back drove the rear wheel at an average speed of 2.5 meters per second. To monitor the bicycle’s position and stability, the engineers attached an LED to the back side of the bicycle, and used a camera mounted behind the bike to monitor the LED’s movement. A gyro sensor attached to the bicycle also detected changes in the bicycle’s direction angle. The researchers could control the bicycle in real time using feedback from these sensors with an RTLinux operating system. As the researchers explained, adjustments to the acceleration (back motor) and steering (front motor) were straightforward because the feedback could be interpreted to have a clear physical meaning. The control system then calculated the necessary motor adjustments. In the experimental set-up, the bicycle ran on rollers. The motor on the handlebars controlled steering, while the motor in the back drove the rear wheel. The gyro sensor, LED, and camera detected the bicycle’s position, which gave feedback to a control system that adjusted the motors to maintain bicycle stabilization. Image credit: Yasuhito Tanaka and Toshiyuki Murakami. ©2008 IEEE. Explore furthercenter_img Citation: Engineers design self-stabilizing electric bicycle (2008, November 4) retrieved 18 August 2019 from https://phys.org/news/2008-11-self-stabilizing-electric-bicycle.html Shared e-cargo bikes: Boom and barriers in Basel (PhysOrg.com) — As every five-year-old knows, balancing on a bicycle is not as easy as it looks. But, as engineers know, getting a bicycle to balance by itself – without a human riding it – is even more difficult.last_img read more

"Engineers design selfstabilizing electric bicycle"

Physicists Propose New Ultracold Scheme for Scalable Quantum Information Processing

first_img(PhysOrg.com) — Since 1994, when Peter Shor famously showed that a quantum computer could factor large numbers exponentially faster than any current classical algorithm, physicists have been investigating a variety of quantum computing schemes. However, truly scalable, controlled entanglement between many particles remains an elusive goal. In a recent study, physicists have proposed a new system that uses ultracold atoms trapped in an optical lattice to generate entanglement, which may be a promising method for realizing a scalable quantum computer due to the high degree of control it offers. In their study, the scientists also show that the system can perform some simple quantum logic gate operations, such as targeted qubit operations, based on the translatable optical lattices at two wavelengths. In addition, the messenger atoms can be used for reading out the quantum information from the qubits. Also, in analyzing the accuracy and uncertainties of the system, the physicists found that fidelities greater than 97% should be possible when entangling distant qubits. The scientists plan to fully demonstrate the system in future work.“Currently we have both atomic species cooled and trapped in a magneto-optical trap and are preparing to further cool the atoms in a second optical trap,” Brickman Soderberg said. “Once the atoms are cold, our immediate goal is to study the interactions between lithium and cesium to identify the best strategy to perform quantum logic operations. Since this is the first time that lithium and cesium have been combined for this purpose, not much work has been done to study the dynamics between the atoms. After that, we will load each atom into its own optical lattice to carry out the qubit operations discussed in the paper.”More information: Kathy-Anne Brickman Soderberg, Nathan Gemelke, and Cheng Chin. “Ultracold molecules: vehicles to scalable quantum information processing.” New Journal of Physics 11 (2009) 055022.Copyright 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. 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. Trapped, Imaged Single Atoms May Enable Powerful Quantum Computing In the new system, lithium and cesium atoms are held in separate optical lattices, and (far right) the atoms can be overlapped by translating the lattices with respect to each other. When the messenger and qubit atoms are overlapped, entangling operations can be performed. Credit: New J. Phys. 11 055022, Kathy-Anne Brickman Soderberg, Nathan Gemelke and Cheng Chin, James Franck Institute and Physics Department, University of Chicago, Chicago, IL 60637, USA.center_img Explore further Citation: Physicists Propose New Ultracold Scheme for Scalable Quantum Information Processing (2009, June 3) retrieved 18 August 2019 from https://phys.org/news/2009-06-physicists-ultracold-scheme-scalable-quantum.html Physicists Kathy-Anne Brickman Soderberg, Nathan Gemelke, and Cheng Chin of the University of Chicago have presented their novel system in a recent issue of the New Journal of Physics. As the scientists explain, the scheme uses two different species of atoms: lithium atoms act as quantum bits to store information, and cesium atoms act as messenger bits that mediate entanglement between distant lithium qubit atoms. Each atomic species is trapped in its own optical lattice, which is an intensity pattern made by several overlapping laser beams. By shifting the relative alignment of the lattices through optical phases, each cesium atom can, in principle, be transported to any distant lithium atom in a controlled way. During this shifting, the cesium atoms can swap entanglement between any two lithium qubit atoms. In the end, the qubit atoms are entangled with each other and the messenger atom is disentangled from the qubits.While previous schemes have also used atoms in optical lattices to implement entanglement, the new proposal is unique in that it introduces the auxiliary messenger atoms. As the scientists explain, independent control of the qubit and messenger atoms provides the key to achieve a large-scale quantum computation. The fact that lithium and cesium atoms have very different dominant atomic transition lines makes it possible to independently confine and control the two species. Atoms trapped in optical lattices have several advantages as a quantum information processing system. As the physicists explain, this kind of system easily lends itself to scalability because thousands of atoms can be isolated in a regular array, and can be transported simply by controlling the optical phases of the lattice beams. Also, since many cesium atoms can be held in the optical lattice, multiple copies of the same computation can proceed in parallel.“Our scheme is scalable in the sense that we do not need to carry out pairwise operations over the lattice to entangle two distant qubits,” Brickman Soderberg told PhysOrg.com. “Instead we can use the messenger atoms to directly carry the entanglement between the qubits. Another strength of our system is that we can individually address our qubit atoms by overlapping the target qubit with a messenger atom, thus eliminating the need for tightly focused laser beams. This will allow us to perform targeted single qubit operations, which may be a necessary step in a large-scale quantum computer.”last_img read more

"Physicists Propose New Ultracold Scheme for Scalable Quantum Information Processing"

SKR researchers develop a 32inch Androidbased multitouch display

first_img Explore further The company released the following statement about the creation of the prototype screen:“Our company makes digital signage, and people were asking us to create a large screen device which has multi-touch functionality like a smart phone. We first tried to make it using Windows 7, but it didn’t meet the needs of our customers. They said they wanted crisp, fluid movement like in a smart phone but with a high-resolution display. But when we asked touch panel and peripheral manufacturers they said they don’t support the Android OS, so we were temporarily stalled. We want to do a lot more work with Android in the future, so we decided to develop the system ourselves.”This means that the company also had to develop their own drivers for the device in order to have a multi-touch display of this size run properly. Of course, this screen will not only come in the 32″ prototype size. When the screens are sold commercially the company expects to sell in a variety of sized, including a 23″ and a 46″. There is also some discussion about the creation of a wide screen version of this device.The product is expected to be ready for commercialization by September, though no release specifics have been given at this time. © 2010 PhysOrg.com (PhysOrg.com) — Researchers at SKR have developed a prototype of a multi-touch 32″ display screen that runs on the Android operating system. The screen, which runs off of a standard Android terminal, is connected to the touch sensors and an HDMI screen via a USB port. The end result of the screen is that the android interface works like smaller devices, but it can also display large format Full HD 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. New keyboard software makes typing faster on touch screens (w/ Video) Citation: SKR researchers develop a 32-inch Android-based multi-touch display (2011, July 6) retrieved 18 August 2019 from https://phys.org/news/2011-07-skr-inch-android-based-multi-touch.htmllast_img read more

"SKR researchers develop a 32inch Androidbased multitouch display"

Physicists discover magnetotoroidic effect

first_img More information: Wei Ren and L. Bellaiche. “Prediction of the Magnetotoroidic Effect from Atomistic Simulations.” Physical Review Letters 107, 127202 (2011). DOI:10.1103/PhysRevLett.107.127202 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 Copyright 2011 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. Magnetic Vortex Switch Leads to Electric Pulsecenter_img (PhysOrg.com) — For many years, scientists have known about the magnetoelectric effect, in which an electric field can induce and control a magnetic field, and vice versa. In this effect, the electric field has always been homogeneous. Now, scientists have found that a curled electric field can also be used to control magnetic fields, constituting a novel phenomenon that they call the “magnetotoroidic effect.” Citation: Physicists discover ‘magnetotoroidic effect’ (2011, September 26) retrieved 18 August 2019 from https://phys.org/news/2011-09-physicists-magnetotoroidic-effect.html “A homogeneous electric field is one in which the electric field is a constant everywhere, as that produced by opposite static charges on two metallic capacitor plates,” Wei Ren of the University of Arkansas told PhysOrg.com. “On the other hand, a time-varying magnetic field can also induce an electric field that possesses a curl according to the Maxwell-Faraday equation. However, such a curl is zero in the homogeneous electric field.”In their study, Ren and coauthor L. Bellaiche, also from the University of Arkansas, have performed atomistic simulations that have confirmed the existence of the new effect, which was previously predicted in theory. Their results are published in a recent issue of Physical Review Letters.In their simulations, the researchers applied a curled electric field to nanodots made of bismuth iron oxide (BFO), which has magnetic properties. They found that, by playing with the magnitude and direction of a vector quantifying the curled electric field, they could control both the magnitude and direction of the nanodots’ magnetization.The simulations also revealed that the effect originates from an interplay among three different components: magnetic dipoles, electric vortices, and oxygen octahedral tilts (from the BFO). When using the curled electric field to control the nanodots’ magnetization, the researchers discovered that the process involves some peculiar intermediate states. One such state, for instance, consists of pairs of electric vortices that coexist with a single antivortex.“Some of our findings are quite surprising and unexpected,” Ren said. “The coexistence of a vortex pair and an antivortex in ferroelectrics has never been reported before, although it is now known as an extremely interesting state in ferromagnetism research areas.”This understanding of the magnetotoroidic effect could enable scientists to use electric fields to better control magnetism, which could have a variety of useful applications. In their paper, the scientists mention the possibility of developing new memory devices with unprecedented storage density.“The MT effect may find applications in the field-induced controlling of magnetic orders, switching of ferroelectric vortex, and modulation of oxygen octahedral tilts,” Ren said. “More importantly, this effect can lead the burgeoning magnetoelectric research to some new arena thanks to the rapid development of nanoscience and engineering.”last_img read more

"Physicists discover magnetotoroidic effect"

Research team develops better iron catalyst to help turn plant material into

first_img Explore further Crude oil no longer needed for plastics (PhysOrg.com) — As most people know, modern plastics are made from crude oil derivatives, making them vulnerable to price and supply fluctuations, which in the end means an alternative must be found in order for the plastics industry to remain viable. One alternative is to use plant material, or biomass instead. Unfortunately, at least till now, the lack of a good catalyst has made the process both expensive and messy, at least for those that create plastics that are virtually identical to the ones based on petroleum. Now, researchers in The Netherlands have found an iron catalyst that appears to be both effective and doesn’t produce a messy byproduct. They describe their work in the journal Science. Citation: Research team develops better iron catalyst to help turn plant material into plastic (2012, February 17) retrieved 18 August 2019 from https://phys.org/news/2012-02-team-iron-catalyst-material-plastic.html More information: Supported Iron Nanoparticles as Catalysts for Sustainable Production of Lower Olefins, Science, 17 February 2012: Vol. 335 no. 6070 pp. 835-838. DOI: 10.1126/science.1215614ABSTRACTLower olefins are key building blocks for the manufacture of plastics, cosmetics, and drugs. Traditionally, olefins with two to four carbons are produced by steam cracking of crude oil–derived naphtha, but there is a pressing need for alternative feedstocks and processes in view of supply limitations and of environmental issues. Although the Fischer-Tropsch synthesis has long offered a means to convert coal, biomass, and natural gas into hydrocarbon derivatives through the intermediacy of synthesis gas (a mixture of molecular hydrogen and carbon monoxide), selectivity toward lower olefins tends to be low. We report on the conversion of synthesis gas to C2 through C4 olefins with selectivity up to 60 weight percent, using catalysts that constitute iron nanoparticles (promoted by sulfur plus sodium) homogeneously dispersed on weakly interactive α-alumina or carbon nanofiber supports. © 2011 PhysOrg.com Journal information: Science Biomass can be used to make plastics by burning it which produces a mix of carbon monoxide and hydrogen. When a catalyst is added to the mix, (most of which are generally based on iron) syngas is produced with olefins in it. The olefins are the components in syngas that form into plastic when they are chemically connected together. The problem up till now has been that the catalysts used thus far haven’t been very efficient (the proportion of olefins in the syngas were very small) and tended to produce carbon dust and methane.In this new research, the team studied many different iron based materials hoping to find one that would work better. After an exhaustive search they discovered that by changing the grain size of one such catalyst material from an average of 500 nanometers to just 20, and then forcing the grains to be evenly spaced apart to prevent clustering, improved efficiency dramatically. Then, by accident (one of their chemicals had been accidently tainted) they found that adding a tiny bit of sulfur and sodium to the mix improved the efficiency even more. The end result is a process so efficient that no carbon dust or methane is produced.The researchers acknowledge that the process still isn’t efficient enough to compete with those based on petroleum products, despite the fact that it produced roughly fifty percent more lower olefins than previous methods. At just 60% efficiency, that still leaves 40% waste, too much for it to be considered a viable replacement, at least at current oil prices and availability. More optimistically, the fact that the team was able to double the efficiency of current methods suggests that even better efficiencies in the future might be found. 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

"Research team develops better iron catalyst to help turn plant material into"

Reports from Humans 2 Mars Summit suggest dust may prevent human settlement

first_img © 2013 Phys.org Explore further The announcement comes on the heels of news from Mars One—the Netherlands based group selling tickets for a one way trip to the red planet—announcing that over 78,000 people have signed up so far. Some of those people might change their mind however when they learn of recent discoveries about the content of Martian dust.NASA’s chief health and medical officer, Richard Williams, told those at the summit that perchlorates appear to be widespread on the planet’s surface. The fine dust material produced by perchloric acid has been known to cause thyroid problems in people here on Earth. Just as problematic, Grant Anderson (co-founder of Paragon Space Development) told the audience, is gypsum. The Curiosity rover has found veins of it near the planet’s surface. Though it’s not toxic, it has been known to cause a condition similar to black lung in coal miners in people exposed to it for long periods of time.Both types of dust particles are in addition to the known presence of silicates on the Martian surface—if breathed-in they can cause reactions with water in the lungs and result in the creation of harmful chemicals.Martian dust could pose health hazards because of the difficulty of removing it from space suits and boots. NASA learned during the Apollo space missions that moon dust was a much bigger problem than had been anticipated. They have reported in the past on the large amounts of dust that stuck to astronaut suits and boots. Fine grains stick to materials because of static electricity, and on Mars would likely be sucked into a controlled environment by an air-lock. Over time, health specialists fear the dust would build up in air filters and living quarters, adding yet another life threatening element to the list of other known hazards (traveling and landing safely, exposure to radiation and cosmic rays, etc.) for the people who seek to colonize the planet.Space technologists have yet to figure out a way to remove the fine particulates from suits and boots and because of that, manned missions to Mars could be put on hold indefinitely. NASA scientists eyeing regional dust storm on Mars (Phys.org) —Reports given by experts in the space-health field suggest it might take longer for humans to build a colony on Mars than has been expected. Such experts speaking to attendees at the recent “Humans 2 Mars Summit” in Washington D.C. expressed concern about the dangers of Martian dust. They believe the health hazards posed by the Martian regolith could prevent humans from colonizing the planet anytime soon. More information: via Newscientist Citation: Reports from “Humans 2 Mars Summit” suggest dust may prevent human settlement of Mars (2013, May 10) retrieved 18 August 2019 from https://phys.org/news/2013-05-humans-mars-summit-human-settlement.html Mars surface. 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

"Reports from Humans 2 Mars Summit suggest dust may prevent human settlement"

Research team develops tattoolike skin thermometer patch

first_imgAn ultrathin device for mapping changes in skin temperature to 0.02 C adheres to the skin surface without the use of glues or tapes. Credit: University of Illinois and Beckman Institute © 2013 Phys.org Explore further (Phys.org) —A diverse team of researchers from the U.S., China, and Singapore has created a patch that when glued to the skin can be used as a thermometer—continuously measuring skin temperature. In their paper published in the journal Nature Materials, the team describes how the patch is made and ways it can be used. The team was led by John Rogers of the University of Illinois—he has been working on ultra-thin electronic skin patches for several years. Just two years ago, he and his team developed a skin patch that sported sensors, radio frequency capacitors, LEDs, transistors, wireless antennas, conductive coils and even solar cells for power. Other researchers have also been hard at work developing patches for applying directly to the skin, or in one case, a tooth. In this latest effort the researchers have fine tuned a patch that resembles a tattoo once applied—it’s meant for one specific task—monitoring skin temperature.The patch is small, of course, just inches across, and extremely thin. It’s also pliable—it’ll keep working even when the skin to which it’s attached twists and turns. The idea for the patch is that it can measure body temperature (at the skin level) very accurately, and over a continuous period of time. Also, because it measures heat at multiple locations (at the same skin site) at the same time, the patch is capable of monitoring heat flow and the constriction and dilation of blood vessels as they respond to the environment around them. Drug patch treatment sees new breakthrough Journal information: Nature Materials In this infrared image, active heating elements of an ultrathin device on the skin appear white due their increased temperature. The device construction allows for application of controlled heating while simulataneously mapping temperature changes to 0.02 °C. Credit: University of Illinois and Beckman Institutecenter_img The patch looks like a bar-code tattoo and is applied using special glue. Thus far, the team has created two versions of the patch that operate in slightly different ways, but offer the same end result—heat readings. The team says that the patches can work in reverse as well, delivering heat to the skin, if desired, simply by increasing the voltage. The patch isn’t ready for use by the general population just yet, however, as it still requires an external power source. The team is investigating different sources for different types of patches—solar for those applied to the skin and bioelectric for those applied inside the body, such as to the outside of organs. More information: Ultrathin conformal devices for precise and continuous thermal characterization of human skin, Nature Materials (2013) DOI: 10.1038/nmat3755AbstractPrecision thermometry of the skin can, together with other measurements, provide clinically relevant information about cardiovascular health, cognitive state, malignancy and many other important aspects of human physiology. Here, we introduce an ultrathin, compliant skin-like sensor/actuator technology that can pliably laminate onto the epidermis to provide continuous, accurate thermal characterizations that are unavailable with other methods. Examples include non-invasive spatial mapping of skin temperature with millikelvin precision, and simultaneous quantitative assessment of tissue thermal conductivity. Such devices can also be implemented in ways that reveal the time-dynamic influence of blood flow and perfusion on these properties. Experimental and theoretical studies establish the underlying principles of operation, and define engineering guidelines for device design. Evaluation of subtle variations in skin temperature associated with mental activity, physical stimulation and vasoconstriction/dilation along with accurate determination of skin hydration through measurements of thermal conductivity represent some important operational examples. An ultrathin device for mapping changes in skin temperature to 0.02 °C is applied to the skin using a water-soluble backing. Credit: University of Illinois and Beckman Institute An ultrathin device for mapping changes in skin temperature to 0.02 °C is shown with a representative colormap of temperature distribution on the wrist. Credit: University of Illinois and Beckman Institute Citation: Research team develops tattoo-like skin thermometer patch (2013, September 16) retrieved 18 August 2019 from https://phys.org/news/2013-09-team-tattoo-like-skin-thermometer-patch.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

"Research team develops tattoolike skin thermometer patch"

Research group figures out a way to film a laser in normal

first_imgLight-in-flight measurement and data cube. (a) A laser pulse is reflecting off multiple mirrors, passing three times across the field of view of the SPAD camera (35 × 35 cm2). The same laser is used to create a trigger sent to the camera. The SPAD camera collects scattered photons from the laser pulse. The field of view does not contain the mirrors because the scattered light coming from the mirror surfaces is much more intense than the Rayleigh-scattered light during propagation. (b) The histogram indicates the time of arrival of the laser pulse as measured by pixel (22, 21). The time frames, shown at 0, 1, 2, 3 and 4 ns, show the evolution of the pulse in time as it propagates across the scene. The integration of all frames gives the total path followed by the light, similarly to what can be acquired by an EMCCD camera at maximum gain for an exposure time of 7 s. Credit: Nature Communications 6, Article number: 6021 doi:10.1038/ncomms7021 Laser beams, by their very nature, travel in a straight line from one point to the next, thus they are nearly impossible to see when traveling through normal air. The path of a single beam can be seen very easily, on the other hand if it happens to pass through smoke, or fog—this is because some of the light in the beam runs into particles that cause some photons to veer from their path and strike a viewers eyes. In this new effort, the researchers wanted to see a beam in normal air, which meant having to use special camera equipment.Normal air has some particles in it, dust, etc.—photons that bounce from such particles can make it to a viewer’s eyes, but they are so few and far between that they cannot be seen. To overcome that problem, the team used a single-photon avalanche diode (SPAD) detector with a very high temporal resolution. It takes a picture of a single photon (using a 32×32 pixel grid) and notes its location. The team pointed the SPAD at a beam as it was bounced off mirrors in a box, over and over (ten million times) during a ten minute period. That allowed for capturing all of the collisions and deflections that occurred during that time span. A computer then knitted all the photon hits together and animated the results, giving a video that very clearly shows the laser beam as it is emitted and then bounces off each of the mirrors in the box. The result is both eerie and very cool to watch. More information: Single-photon sensitive light-in-fight imaging, Nature Communications, 6, Article number: 6021 DOI: 10.1038/ncomms7021AbstractThe ability to record images with extreme temporal resolution enables a diverse range of applications, such as fluorescence lifetime imaging, time-of-flight depth imaging and characterization of ultrafast processes. Recently, ultrafast imaging schemes have emerged, which require either long acquisition times or raster scanning and have a requirement for sufficient signal that can only be achieved when light is reflected off an object or diffused by a strongly scattering medium. Here we present a demonstration of the potential of single-photon detector arrays for visualization and rapid characterization of events evolving on picosecond time scales. The single-photon sensitivity, temporal resolution and full-field imaging capability enables the observation of light-in-flight in air, as well as the measurement of laser-induced plasma formation and dynamics in its natural environment. The extreme sensitivity and short acquisition times pave the way for real-time imaging of ultrafast processes or visualization and tracking of objects hidden from view. 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: Nature Communications Explore further (Phys.org)—A team of researchers working at the Institute of Photonics and Quantum Sciences, Heriot-Watt University, in Scotland has developed a method for filming a laser beam as it bounces back and forth between mirrors—in normal air. In their paper published in the journal Nature Communications, the team describes how they did it and share the video they created. © 2015 Phys.orgcenter_img Researchers build reversible tractor beam that moves objects 100 times farther than other efforts 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 Light propagation in air. Credit: Nature Communications 6, Article number: 6021 doi:10.1038/ncomms7021 Though it is not clear just yet if the technique will have any real applications (such as watching plasma develop as ions are heated), the team appears satisfied with their work noting that they were able to achieve their goal. Play Formation and evolution of laser-induced plasma. Credit: Nature Communications 6, Article number: 6021 doi:10.1038/ncomms7021 Citation: Research group figures out a way to film a laser in normal air bouncing off mirrors (w/ Video) (2015, January 29) retrieved 18 August 2019 from https://phys.org/news/2015-01-group-figures-laser-air-mirrors.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

"Research group figures out a way to film a laser in normal"

Cat shelter findings Less stress with box access

first_img Citation: Cat shelter findings: Less stress with box access (2015, February 8) retrieved 18 August 2019 from https://phys.org/news/2015-02-cat-stress-access.html © 2015 Phys.org 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. Journal information: Applied Animal Behaviour Science More information: Applied Animal Behaviour Science, www.appliedanimalbehaviour.com … 0236-6/abstract?cc=y Out of all those cat videos that keep your eyes glued to the screen far longer than you would care to acknowledge, you may have seen some showing little and big cats trying their best to snuggle into big and too-little cardboard boxes. What makes them so content about being in a box? Scientists have spent much time looking for answers. “Will a hiding box provide stress reduction for shelter cats?” That is one such exploration, published in Applied Animal Behaviour Science, the journal of the International Society for Applied Ethology (ISAE). The three authors, from the Faculty of Veterinary Medicine, University of Utrecht, studied stress in shelter cats and found that hiding boxes reduced stress, at least on the short term. They chose shelters as their investigation site because that is where the stress levels for domestic cats can be serious. The researchers assessed the effect of a hiding box on stress levels of newly arrived cats in a Dutch animal shelter. Ten cats had a box; nine did not. They found a significant difference between the two groups on observation days 3 and 4. The cats with the hiding box were able to recover faster in their new environment.Writing in Wired, Bryan Gardiner took up the topic of why cats love boxes, discussing the researchers’ findings as well as other explorations into the way cats love scampering and even squeezing into boxes. One of the authors of the Dutch cat shelter paper, Claudia Vinke, was quoted in Wired: “Hiding is a behavioral strategy of the species to cope with environmental changes and stressors,” Vinke said in her email. Cornell University’s College of Veterinary Medicine, in their observations about cat shelters and stress, said that “cats benefit greatly from the ability to hide when stressed. In shelters, this can be accomplished in a variety of ways, with a range of costs and benefits.” One type of hiding spot which they recommended was a “hiding box” which they said could be “a cardboard box, a specially designed Hide-Perch-and-Go box, a sturdier plastic box or cage insert, a plastic carrier, or a commercially available “cat den.” The Cornell site said that while cardboard boxes are inexpensive, they cannot be cleaned, and must only be used for one cat before being discarded or recycled. Gardiner in Wired made the point that boxes are not the only enclosures that attract cats; bowls, a bathroom sink, or other enclosures seem to work, too. Gardiner also made the point that cats scramble for such enclosures in a fundamental search not merely to feel psychologically cozy but for heat.”According to a 2006 study by the National Research Council, the thermoneutral zone for a domestic cat is 86 to 97 degrees Fahrenheit. That’s the range of temperatures in which cats are ‘comfortable’ and don’t have to generate extra heat to keep warm or expend metabolic energy on cooling.” Corrugated cardboard, he added, is a good insulator; if the box is a tight squeeze so much the better; it may “force the cat to ball up or form some other impossible object, which in turn helps it to preserve body heat.” A cat’s game of hide and seeklast_img read more

"Cat shelter findings Less stress with box access"

Gorilla mobs attacking single individuals suggests new type of behavior for them

first_img(Phys.org)—A trio of researchers studying gorillas in Karisoke Research Center in Rwanda has reported on a developing trend observed in mountain gorillas—mobs attacking single individuals for unknown reasons. In their paper published in Scientific Reports, Stacy Rosenbaum, Veronica Vecellio and Tara Stoinski describe three mob attacks that have been observed by several human witnesses over the past decade and offer some possible explanations. Credit: CC0 Public Domain Journal information: Scientific Reports More information: Stacy Rosenbaum et al. Observations of severe and lethal coalitionary attacks in wild mountain gorillas, Scientific Reports (2016). DOI: 10.1038/srep37018AbstractIn humans and chimpanzees, most intraspecific killing occurs during coalitionary intergroup conflict. In the closely related genus Gorilla, such behavior has not been described. We report three cases of multi-male, multi-female wild mountain gorilla (G. beringei) groups attacking extra-group males. The behavior was strikingly similar to reports in chimpanzees, but was never observed in gorillas until after a demographic transition left ~25% of the population living in large social groups with multiple (3+) males. Resource competition is generally considered a motivator of great apes’ (including humans) violent intergroup conflict, but mountain gorillas are non-territorial herbivores with low feeding competition. While adult male gorillas have a defensible resource (i.e. females) and nursing/pregnant females are likely motivated to drive off potentially infanticidal intruders, the participation of others (e.g. juveniles, sub-adults, cycling females) is harder to explain. We speculate that the potential for severe group disruption when current alpha males are severely injured or killed may provide sufficient motivation when the costs to participants are low. These observations suggest that the gorilla population’s recent increase in multi-male groups facilitated the emergence of such behavior, and indicates social structure is a key predictor of coalitionary aggression even in the absence of meaningful resource stress. For most of the modern study of gorillas in their native environment, the consensus has been that they are generally docile with one another—there have been observations of males fighting, sometimes to the death, but for the most part, the life of the gorilla was thought to be one of mostly peaceful. But now, it appears that the peace can be disturbed by the occasional mob attack on a single individual or, as the researchers note, two individuals.In the first witnessed attack, back in 2004, Rosenbaum was actually one of the witnesses. She describes the incident as arising seemingly out of nowhere. A single male the team had named Inshuti approached a group of gorillas the researchers had named the Beetsme. After some initial rebuffs, the lone male continued to seek acceptance. Then one of the gorillas screamed—the witnesses could not say if it was Inshuti or a member of the group. That was followed by three adult males chasing Inshuti until they caught him and pinned him to the ground. Soon thereafter, the rest of the Beetsme group arrived and all of them (including females and youngsters) participated in causing harm to Inshuti—from pulling hair to scratching and kicking. The leader of the Beetsme sunk his teeth into the gorilla’s flesh and shook it like a fighting dog. The mob attack continued for just a few minutes, but then stopped just as quickly as it had started. The attackers walked away and Inshuti slunk into the underbrush to attend to his wounds.The researchers report on two other similar incidents, one of which included an attack on Inshuti and another male. They note that mob attacks by other apes, including chimps, is common, as in humans, but until these recent incidents, it was thought gorillas were gentle giants, unlikely to engage in such violence. The team admits they do not know why the gorillas have begun acting like mobs at times but note that it has occurred during a time when the mountain gorilla population has grown due to conservation efforts. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.center_img Who’s your daddy? If you’re a gorilla, it doesn’t matter © 2016 Phys.org Explore further Citation: Gorilla mobs attacking single individuals suggests new type of behavior for them (2016, November 28) retrieved 18 August 2019 from https://phys.org/news/2016-11-gorilla-mobs-individuals-behavior.htmllast_img read more

"Gorilla mobs attacking single individuals suggests new type of behavior for them"