In forty jumps scientists model scales of quarks to quasars

first_img Ray-tracing software lets researchers visualize science with greater fidelity “Graphics displays have faced a limitation due to their digital nature,” Hanson explained to PhysOrg.com. “For example, handling large ranges in detail is out of the range of standard hardware, such as accelerated graphics cards. With this new system, we can create an accurate, interactive experience, with continuous scaling over different scale ranges. You can wander continuously throughout the universe without any anomalies.”Fu and Hanson’s work tackles several problems that past systems have faced: focusing on objects at different distances, depth perception, and speed. As Hanson explains, it’s a bit like looking at a ladybug on your nose with the galaxy in the background. To improve these areas, the scientists developed a graphics software system that provides a continuously scalable visualization in three dimensions. Citation: In ‘forty jumps,’ scientists model scales of quarks to quasars (2007, January 18) retrieved 18 August 2019 from https://phys.org/news/2007-01-forty-scientists-scales-quarks-quasars.html Hanson and Fu designed their software by extending the powers-of-ten framework, shown for common objects in this table. Image Credit: Andrew Hanson, et al. © 2006 IEEE. Comprehending the smallness of a quark or the hugeness of the observable universe is a challenge that most of us find difficult, yet captivating. Placing vastly different scales side by side to explore their relationship amounts to a task not even computers have mastered efficiently. Recently, scientists Chi-Wing (Philip) Fu and Andrew Hanson have developed a visualization system of the universe that may help scientists, educators and film viewers better understand size on a journey through the universe. The content of the system—stars, galaxies, supernovae, etc.—comes from an extraordinary collection of data from exploration systems such as the Sloan Digital Sky Survey, the Bright Star Catalogue, Hubble and other telescopes. In their study, Fu and Hanson present a “powers-of-ten journey,” starting, e.g., from Earth (107 m) up through the solar system (1013), the Pleiades cluster (1018), the Andromeda galaxy (1023), and beyond (see figure).Like previous computer graphics programs studying outer space, Fu and Hanson predict that this system could not only have use for astronomers and physicists studying the universe, but for educational and commercial purposes, as well. IMAX shows and planetarium presentations have excited young enthusiasts with their realistic animations, and as computational power continues to grow, the public can also benefit from Fu and Hanson’s scale visualization technology.“Our motivation was to create a framework for a real-time digital planetarium,” said Hanson. “With this framework, we’ve created a series of layers of objects across an enormous scale range, all on a single screen.”Citation: Fu, Chi-Wing and Hanson, Andrew J. “A Transparently Scalable Visualization Architecture for Exploring the Universe.” IEEE Transactions on Visualization and Computer Graphics, Vol. 13, No. 1, January/February 2007.By Lisa Zyga, Copyright 2006 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.center_img Because a normal “zoom” feature would take an impractical amount of time due to the vast precision required, Fu and Hanson used a new approach: power-scaled coordinates (PSC). The scientists were inspired by a film called “Powers of Ten” by Eames and Eames, which itself was based on the 1957 children’s book Cosmic View: The Universe in Forty Jumps by Boeke. “We asked ourselves, ‘how do you provide that experience [of the film]?’” said Hanson. “We extend that ‘powers of ten’ framework by making this system interactive instead of pre-computed and pre-stored.”Fu and Hanson’s PSC system works by representing coordinates and vectors using logarithmic scaling methods, enabling the system to handle all scales in a single context for interactive control by the user. One of the novel PSC-based ideas in the architecture is a “depth rescaling method,” which can project objects across extreme scales with the needed precision by distorting the vertices of distant background objects. Also, to accelerate the rendering of objects during navigation, the system uses “environmental caching” and “object disappearance” to develop pre-rendered backgrounds and ignore objects that are not large or luminous enough to appear on the screen. On a desktop computer, the program achieves interactive speeds. 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. From the top left and moving across, this powers-of-ten journey shows Earth (red line represents the ISS) (107 m), Earth and satellites (108 m), solar system (1013 m), Pleiades (1018 m), extrasolar planets (1018 m), and the Milky Way and Large Magellanic Cloud (1023 m). Image Credit: Andrew Hanson, et al. © 2006 IEEE.last_img read more

Cube Slam Googles video game plays up WebRTC WebGL

first_img More information: plus.google.com/+chrome/posts/BkJmjzDicSh © 2013 Phys.org Explore further WebRTC is available on desktop Chrome and Chrome OS, and will be available on mobile later this year. Game visitors, though, can play Cube Slam against Bob the Bear on a smartphone or tablet. Cube Slam’s graphics are rendered in WebGL. For Chrome and Firefox users, WebGL brings hardware-accelerated 3-D graphics to the browser without installing additional software. If you don’t have WebGL, says Google, you can still play Cube Slam in 3-D with CSS3, which allows developers to build their web pages with the same game engine running under the hood. CSS3 stands for Cascading Style Sheets. Google noted that all the graphics run on your GPU, freeing the CPU for other tasks.The soundtrack comes by way of Web Audio, which is used for games and interactive applications. The Cube Slam music-tracker and sound manager are built on the Web Audio API. The soundtrack adapts in real-time to every level reached. WebRTC puts video chats all in the browser (Phys.org) —Google has a new game called Cube Slam where you get to slam a cube into another player’s screen target. If you hit the cube against the other player’s screen three times, terrific, the screen shatters. To keep the game from getting dull, varied levels are part of the mix, complete with obstacles and gravity fields to keep players challenged. This is as addictive as an old-time video arcade game but supplemented with video chat as well. A share link gets the two players going. Google’s CubeSlam debut falls under the Google umbrella of Chrome Experiments, a showcase for web experiments. Most of these experiments are built with the latest open technologies: HTML5, Canvas, SVG, and WebGL. “We hope they show how the web has become faster, more fun, and more open – the same spirit in which we built Google Chrome.” Citation: Cube Slam: Google’s video game plays up WebRTC, WebGL (2013, June 14) retrieved 18 August 2019 from https://phys.org/news/2013-06-cube-slam-google-video-game.html To underscore not only fun but technologies such as WebRTC and WebGL as great ingredients for web innovating, a game like Cube Slam with ample pointers to the way it was built appears to be a clever slam dunk. The blurb on the home page of Chrome Experiments invites first-time hopefuls to play the game where “Video chat meets video game in this new experiment featuring WebGL and WebRTC. Play face-to-face against a friend just by sending a link.”WebRTC is a web standard that enables web browsers with Real-Time Communications (RTC) capabilities via simple Javascript APIs. That means that RTC applications can be developed right in the browser. The underlying technology comes from Global IP Solutions, a 2010 Google acquisition. Google opened the source code, with the intention of greasing the wheels toward standardization. Web RTC stands for Web Real Time Communication. Google does not own it; it’s an open source project supported by Google, along with Mozilla and Opera. Components such as VoiceEngine, VideoEngine, NetEQ stem from the acquisition. “Cube Slam is built using WebRTC, an open web technology that lets you video chat with your friends right in the browser, no plug-ins necessary. The getUserMedia API provides access to your webcam and microphone, RTCPeerConnection sends the audio and video to your friends, and RTCDataChannel exchanges all the bits and pieces that keep the game in sync. When there are no firewalls in the way, game data can be sent directly peer-to-peer, greatly reducing server costs.” 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 create light bullets for highintensity optical applications

first_img The scientists, P. Panagiotopoulos, D.G. Papazoglou, A. Couairon and S. Tzortzakis, from institutions in Greece and France, have published a paper in a recent issue of Nature Communications in which they show theoretically and experimentally how ring-Airy beams transform into light bullets.An airy beam is a type of light beam that has the distinct feature of forming a parabolic arc as it propagates through space. In fact, it gets its name from the Airy integral, developed in the 1830s by Sir George Biddell Airy to describe the way light bends in a rainbow. In 2011, scientists (including some of the authors of the current paper) experimentally demonstrated an Airy beam in the shape of a ring. In the linear regime, this ring-Airy beam can focus itself into a sharp focal point, which could make it an ideal candidate for precise laser ablation applications in hard-to-reach environments.In the new study, the scientists have investigated the properties of ring-Airy beams in the non-linear regime, and found them to be even more impressive than in the linear regime. The scientists found that the ring-Airy wavepacket reshapes itself into a propagating high intensity light bullet that spreads neither in space nor in time over significantly longer distances than Gaussian beams, which are often used in conventional lasers.The researchers also found that, when the input power is increased, the ring-Airy beam’s focus position is not shifted nearly as much as it is for Gaussian beams. The researchers could mathematically predict the position of the ring-Airy beam’s focus for a given input power, which they confirmed through experiments.These highly focused, high-intensity ring-Airy beam light bullets offer a very high level of control that cannot be achieved with equivalent Gaussian beams, making them ideal for a variety of optical applications ranging from precision materials processing to attosecond drivers. Citation: Scientists create light bullets for high-intensity optical applications (2013, November 12) retrieved 18 August 2019 from https://phys.org/news/2013-11-scientists-bullets-high-intensity-optical-applications.html Journal information: Nature Communications More information: P. Panagiotopoulos, et al. “Sharply autofocused ring-Airy beams transforming into non-linear intense light bullets.” Nature Communications. DOI: 10.1038/ncomms3622 © 2013 Phys.org. All rights reserved. (Phys.org) —Controlling the propagation of high-intensity light beams as they travel through air (or other transparent media) is a challenging task, but scientists have now shown that a relatively new type of light beam called a ring-Airy beam can self-focus into intense light bullets that propagate over extended distances. These well-defined, high-intensity optical wavepackets could have applications in a variety of areas, such as laser micromachining and harmonic generation.center_img Explore further Researchers discover a way to generate an electron Airy beam Compared to two types of Gaussian beams (EEGB and ECGB), the ring-Airy wavepacket has a more precisely focused shape, appearing as a ‘light bullet.’ The wavepacket shapes are shown at different distances as the beams propagate from left to right. Credit: P. Panagiotopoulos, et al. ©2013 Macmillan Publishers Limited 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

Best of Last Week – New definition of time crystals new images

first_img(Phys.org)—It was an interesting week for physics as a team of researchers with the University of California and the University of Tokyo proposed a new definition of time crystals—then proved such things don’t exist—theory had suggested a system that could move despite not having enough energy to do so. Also, a team at Ecole Normale Supérieure in France demonstrated a way to control the quantum properties of light by using microwave photons to probe a superconducting circuit. And researchers working for the Department of Energy used neutrons to find the “missing” magnetism of plutonium—confirming a long held theory. Boeing patent puts focus on laser-powered propulsion system (Update) It was also an interesting week for space exploration, mostly notably regarding reports describing findings by NASA’s New Horizon spacecraft as it approaches Pluto—first, as the craft moved closer, new geological features began to appear. Then, after getting even closer to the dwarf planet, researchers noted a heart-shaped feature on the surface—though they still do not know what it is. Such news highlights a problem developing within NASA and other space research groups: How will we know when we have found extraterrestrial life? Phys.org spoke to Terence Kee, President of the Astrobiology Society of Britain to gain some insight. In related news, a new Boeing patent put focus on laser-powered propulsion systems for airplanes, and potentially for spacecraft as well. The idea appears to involve firing a laser at a piece of radioactive material, setting off a small fusion reaction. Boeing has not commented publicly on the patent or idea.In other news, a team of researchers at Pennsylvania State University College of Medicine wondered: Can four fish oil pills a day keep the doctor away? They believe the answer is yes, at least for older people who take the pills for at least three months. Also, somewhat ominously, researchers with NASA’s Jet Propulsion Laboratory working on a new study found that heat is being stored beneath the ocean surface. That helps to explain where all the excess heat due to greenhouse gases has been going, but it also poses the question of what happens when the saturation point is reached.And finally, if you are one of the millions of people who suffer with some type of chronic pain, good news may be coming soon as a team of researchers at the University of California has found the key mechanism that causes neuropathic pain—they believe the discovery will open the door to new treatments that will finally alleviate suffering from such ailments as trauma, diabetes, MS, shingles and a host of other conditions. © 2015 Phys.org Explore furthercenter_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Best of Last Week – New definition of time crystals, new images of Pluto and the mechanism that causes neuropathic pain (2015, July 13) retrieved 18 August 2019 from https://phys.org/news/2015-07-week-definition-crystals-images-pluto.html Zeno cat. A Zeno cat refers to non-classical states of light created by shining a cavity on resonance while it is forbidden to access a given energy level. The name originates from the Zeno effect, which can similarly prevent an energy level from being occupied by the sole fact of measuring its occupation frequently. The cat comes from the similarity of such a state with a Schrödinger cat state of light: a superposition between two classical states of light. The Zeno cat figure corresponds to the study’s experimental design. Credit: Benjamin Huard.last_img read more

New version of Vantablack coating even blacker than original

first_img Explore further Since it was first developed three years ago and marketed, artists and manufacturers have shown interest in using the coating to create unique-looking products—a watch from Contemporaine du Temps, for example, designed by British artist, Anish Kapoor, features Vantablack on its dial and minute hand—it adds a degree of depth to the watch that other watches do not have.Representatives for Nanosystems have told the press that they believe that Vantablack could also be used to improve the performance of cameras and sensors—the only drawback is that the coating is still too delicate for use in commercial applications, though it has been used on some star-tracking satellites. Vantablack is made by chemically growing a network of carbon nanotubes (each of them is just 20 nanometers in diameter and approximately 14 microns to 50 microns in length) in a high-temperature chamber, creating a forest of sorts on a base such as aluminum—the nanotubes are so small and dense that the company reports that over a billion of them exist on a 0.1 in square patch. The material is then applied as a coating to another object—light hitting the coating is absorbed because it is bounced around between the nanotubes instead of being reflected back. Such materials have an eerie look, as they appear to be missing features normally seen in other black materials. The result is striking—coated objects appear is if they have been photoshopped to remove all traces of contours and other features. It is only by changing the angle of objects coated with the material that features are visible.Nanosystems has also reportedly developed a spray version of Vantablack (Vantablack S-VIS.) which should make the coating more accessible to anyone who wants to use it, though it is not quite as black. Credit: Surrey Nanosystems (Phys.org)—U.K.-based Surrey Nanosystems has announced that it has improved on the original Vertically Aligned Nanotube Array BLACK (Vantablack coating) which the company claimed to be the blackest material ever made. The original Vantablack was found to absorb 99.96 percent of visible (and ultraviolet and infrared) light—the new Vantablack is darker—so much so that it cannot be measured by a spectrometer. Citation: New version of Vantablack coating even blacker than original (2017, April 11) retrieved 18 August 2019 from https://phys.org/news/2017-04-version-vantablack-coating-blacker.htmlcenter_img © 2017 Phys.org Credit: Surrey Nanosystems Surrey NanoSystems has “super black” material 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

Compact 3D quantum memory addresses longstanding tradeoff

first_img © 2018 Phys.org Physicists have designed a 3-D quantum memory that addresses the tradeoff between achieving long storage times and fast readout times, while at the same time maintaining a compact form. The new memory has potential applications in quantum computing, quantum communication, and other technologies. Journal information: Applied Physics Letters Citation: Compact 3-D quantum memory addresses long-standing tradeoff (2018, June 4) retrieved 18 August 2019 from https://phys.org/news/2018-06-compact-d-quantum-memory-long-standing.html Record-breaking efficiency for secure quantum memory storage Explore furthercenter_img More information: Edwar Xie, et al. “Compact 3-D quantum memory.” Applied Physics Letters. DOI: 10.1063/1.5029514 The physicists, Edwar Xie and coauthors at the Walther-Meissner-Institut, Technical University of Munich, and Nanosystems Initiative Munich (NIM), Germany, have published a paper on the new 3-D quantum memory in a recent issue of Applied Physics Letters.”Since quantum information is very fragile, it needs to be processed fast or preserved in a suitable storage. These two requirements are typically conflicting,” Xie told Phys.org. “The greatest significance of our work is that it shows how to build a device with fast access to stored quantum information, enabling fast processing, combined with a long storage time.”One of the greatest challenges facing any kind of quantum technology is enhancing the qubit lifetime, and when it comes to quantum memories, 3-D devices offer the longest coherence times, up to a few milliseconds. In these memories, qubits are stored in 3-D microwave waveguide cavities, whose slow decay times enable long qubit storage times. However, a tradeoff occurs in these devices, since fast readout times require the cavity decay to be fast.Previously, researchers have addressed this tradeoff in various ways, such as by physically separating the storage and readout units. However, with separate units the devices become relatively large and bulky compared to 2-D memories, causing problems for scalability.In order to simultaneously achieve long storage times, fast readout times, and a small footprint, in the new study the researchers made use of the multimode structure of 3-D cavities. In this approach, the researchers used antennas to couple a qubit to two distinct modes of a single 3-D microwave cavity, which is much more compact than using two entirely separate units. They engineered the cavity so that the memory mode has a quality factor that is 100 times larger than that of the readout mode, which leads to slow decay for the memory mode and fast decay for the readout mode.As a result of this coupling, the researchers demonstrated that the qubit state can be read out on a timescale that is 100 times shorter than the storage time. Further, simulations showed that more accurate antenna positioning could extend the ratio between readout and storage time to 25,000. This value would significantly outperform the current highest reported ratio of 7300 for quantum memories with cylindrical 3-D cavities.In the future, the researchers plan to make further improvements to the memory, such as scaling up by adding more qubits, coupling the qubit to higher cavity modes, and enabling the memory to store cat states (a superposition of two macroscopic states), which has potential applications in continuous variable quantum computing. “One potential application of this compact 3-D quantum memory lies in the field of analog quantum simulation, where an engineered quantum circuit, such as a qubit, mimics an atom,” Xie said. “Due to its compact size and relaxed requirements of cabling, our 3-D quantum memory platform is specifically suitable for building chains of artificial atoms for the simulation of molecules. Here, one cell of the chain consists of a single 3-D cavity with one qubit, a storage mode for intermediate information storage and a readout mode for fast information retrieval. The coupling to the neighboring cell can be achieved with another qubit.” (a) Photograph of the 3D quantum memory and (b) optical micrograph of a qubit. Credit: Xie et al. ©2018 American Institute of Physics 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

Multifaceted design optimization for superomniphobic surfaces

first_img LEFT: Simulation surface configuration. Illustration of the 3D simulation repeat unit, with 2D cross section showing labeled structural parameters. RIGHT: Quantification and mechanisms leading to the CAH (contact angle hysteresis) for reentrant and doubly reentrant geometries at zero applied pressure. (A) (i) CAH dependence on both the area fraction Fr and total cap height Dr. Symbols indicate the depinning mechanism upon receding, with purple diamonds indicating a hybrid mechanism. (ii and iii) Comparison of the bridge-, edge-, and lip-depinning receding models (solid lines, color-coded) against the simulated θr (data points); examples shown with varying Fr at fixed Dr = 0.05 and 0.35. The ±1° error bars in the simulation data are too small to be seen. (B) 3D visualization of the advancing liquid-vapor interface (shown in blue); the advancing direction is indicated by a black arrow. Black and red lines indicate the center and edge 2D cross sections that are also presented (right). (C) (i to iv) Visualizations of the major four receding mechanisms. The receding direction is indicated by black arrows. Credit: Science Advances, doi: 10.1126/sciadv.aav7328 , Proceedings of the National Academy of Sciences Journal information: Science Advances In this way, the scientists developed highly versatile computational techniques to study any mesoscopically structured surface in contact with multiple fluid phases. The multifaceted optimization strategy can be further improved for reliability and scalability to couple with recent advances in fabrication including 3-D printing and lithographic methods to efficiently design real-world superomniphobic surfaces. In materials science, surfaces that strongly repel low surface tension liquids are classified ‘superoleophobic,” while high surface tension liquid repellants are ‘superhydrophobic’ and surfaces that display both characteristics are ‘superomniphobic.” Superomniphobic surfaces are at the frontiers of surface design for a vast array of applications. In a recent study, J. R. Panter and co-workers at the Department of Physics and Procter and Gamble Co. in the U.K. and the U.S. developed computational methods to systematically develop three key surface wetting properties. These included contact angle hysteresis, critical pressure and a minimum energy wetting barrier. In the study, the scientists developed quantitative models and corrected inaccurate assumptions within existing models. When studying the third parameter on minimum energy transition mechanisms, the scientists identified three failure mechanisms. For instance, a surface design failure can be initiated through a broad range of additional perturbations including flow, vibration, evaporation, condensation, droplet impact, changing electrical and magnetic fields or thermal fluctuations at the nanoscale. In real-world applications, failure could be initiated by a combination of perturbations. To fabricate a texture resistant to failure, Panter et al. therefore combined the maximum energy pathway (MEP) to account for a worst case scenario of combined failures. They identified three transition pathways as (1) base contact (BC), (2) pillar contact (PC) and (3) cap contact (CC), then quantified each barrier across the structural parameter space. Thereafter, they assessed the likeliest mechanism of energy transition for a given surface geometry. The scientists then conducted simultaneous optimization of the identified structural features to maximize critical pressure, minimize the energy barrier and maximize the CAH. For this, they performed optimal design of two membranes for applications on water purification and digital microfluidics. Panter et al. also showed that a genetic algorithm could be used to efficiently locate the optimum design in the parameter space and design more complex structures for special wettability applications. Critical pressure analysis for reentrant and doubly reentrant geometries. (A) Contour plots of ΔPc variation with Fr and Hr for reentrant (i) and doubly reentrant (ii) geometries. Data points mark the critical height at which the failure mechanism switches from Base Failure (BF) to Depinned Cap Failure (DCF) or Pinned Cap Failure (PCF), and error bars indicate the uncertainty in this height due to the diffuse interface width. Solid and dashed white lines show the critical height based on the capillary model and 2D model, respectively. (B) Model fits to ΔPc of the Cap Failure mechanisms at Hr = 0.25 for reentrant (i) and doubly reentrant (ii) geometries. (C to E) The three failure mechanisms shown in 3D, with associated diagonal cross sections. Critical pressure liquid morphologies are shown in blue, the vapor phase is shown in white, and the interface is indicated with a black solid line. Red regions show how the unstable meniscus evolves upon increasing ΔP above ΔPc. (D and E) Under-cap views, highlighting the shapes of the contact lines at the critical pressure. (F) Details of the 3D horizontal (3DD) and 3D diagonal (3DH) capillary bridge models used, showing the inner and outer circumferences (blue) against the system configuration. The 3D illustration compares the simulated liquid-vapor interface (light blue) to the horizontal capillary model (dark blue). Credit: Science Advances, doi: 10.1126/sciadv.aav7328 Explore further Simultaneous optimization of the three wetting properties for membrane distillation and digital microfluidics applications. (A) (i) 3D contour plot of the membrane distillation scoring function at fixed Hr = 0.3, Ar = 0.05, and tr = 0.05. Each surface is a surface of constant score. (ii) A 2D slice of the 3D contour plot at the optimal Lr = 0.17. Square data points show the initial (white), second (light gray), fifth (dark gray), and final (black) generations of the genetic algorithm, projected onto the 2D plane. (B) Scoring function for the digital microfluidics application, projected onto the Hr = 0.3 plane at fixed B = 100 μm, also showing the successive generations of the genetic algorithm population. Credit: Science Advances, doi: 10.1126/sciadv.aav7328 Making a splash is all in the angle Video shows the pillar contact (PC) mechanism for a doubly reentrant geometry at θ° = 60° a surface property identified in the study. Credit: Science Advances, doi: 10.1126/sciadv.aav7328 Panter et al. combined these analyses simultaneously to demonstrate the power of the strategy to optimize structures for applications in membrane distillation and digital microfluidics. By antagonistically coupling the wetting properties, the scientists implemented a multifaceted approach to optimally design superomniphobic surfaces. Using genetic algorithms, they facilitated efficient optimization for speedups of up to 10,000 times. The results of the study are now published on Science Advances. Superomniphobic surfaces have physical micro- and nanotextures that allow low-surface-tension liquids (oils and alcohols) to remain suspended on a vapor-filled surface structure. This liquid-shedding ability can promote efficient droplet mobility with low viscous drag , with transformative potential across a broad range of applications. These include sustainable technologies for water purification, antimicrobial strategies in biomedicine, anti-fingerprint coating techniques, reducing food waste and versatile biochemical technologies, at the global scale. Recent breakthroughs in microfabrication have allowed the formation of complex structures at the micrometer scale resolution, including three-dimensional (3-D) printing technology, fluidization of polymer micropillars and lithographic methods. Despite these highly versatile techniques, materials scientists and physicists still seek to understand how to precisely design surface structures for optimal performance in real-world applications. A successful omniphobic design must demonstrate three key wetting properties to include (1) a low contact angle for maximum liquid mobility, (2) high critical pressure for stability of the superoleophobic state, and (3) a high energetic barrier to failure. Due to complexities of surface design, uniting computational and experimental studies can be expensive and time-consuming to understand this basis. In the present work, Panter et al. overcame the challenges of designing superomniphobic wetting properties by first designing computational strategies to understand the effect that structural parameters had on the three defined criteria. To illustrate the importance of multifaceted optimization they used two relevant examples of water purification via membrane distillation and droplet-based digital microfluidics. The scientists developed a genetic algorithm to efficiently perform simultaneous optimizations with speedup to 10,000 times. This versatile approach can be coupled to recent innovations in complex surface microfabrication techniques to offer a transformative approach to surface design. The scientists first simulated the liquid vapor interface advancing and receding along a single row of surface structures to obtain their respective contact angles and contact angle hysteresis (CAH, i.e., the difference between advancing and receding contact angles). They arranged the variable dimensions in a square array and observed the hysteresis to be identical for both reentrant and doubly reentrant geometries (geometries with very low liquid-solid contact fraction). Using the simulation, the scientists observed four dominant receding mechanisms to describe and model them in the present work. Thereafter, using the new models Panter et al. qualitatively tested the receding models proposed in previous studies to verify their accuracy. They analyzed the energetic changes to obtain the angle at which receding became energetically favorable to form the optimal receding angle. Unlike simulations of CAH, the second parameter of interest on critical pressure was sensitive to the reentrant or double reentrant surface geometry. The scientists observed three failure mechanisms in the critical pressure study and quantified them as a function of the structural parameters. When they compared quantification in the present work with simulation data, they detected prevailing and widely used critical pressure models introduced in previous studies to be considerably oversimplified. For instance, poor description of the liquid-vapor interface morphology prompted manufactured structures to be many times smaller and mechanically weaker than necessary. By developing a more sophisticated model in the present work, Panter et al. achieved both quantitative accuracy of the critical pressures and successfully modeled the desired complex interfacial morphologies. More information: J. R. Panter et al. Multifaceted design optimization for superomniphobic surfaces, Science Advances (2019). DOI: 10.1126/sciadv.aav7328 Arun K Kota et al. The design and applications of superomniphobic surfaces, NPG Asia Materials (2014). DOI: 10.1038/am.2014.34A. Tuteja et al. Robust omniphobic surfaces, Proceedings of the National Academy of Sciences (2008). DOI: 10.1073/pnas.0804872105 A. Tuteja et al. Designing Superoleophobic Surfaces, Science (2007). DOI: 10.1126/science.1148326 , Science Demonstrating a failure mechanism identified in the study, video shows the base contact (BC) mechanism for a doubly reentrant geometry at θ° = 60°. Credit: Science Advances, doi: 10.1126/sciadv.aav7328 © 2019 Science X Network Citation: Multifaceted design optimization for superomniphobic surfaces (2019, June 28) retrieved 18 August 2019 from https://phys.org/news/2019-06-multifaceted-optimization-superomniphobic-surfaces.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

Of the artiste and her art

first_imgThe book was released by Szilveszter Bus, Ambassador-Designate of Hungary. The launch was followed by an illustrated lecture, Amrita Sher-Gil, Paris, and the Bloomsbury Group, by an art historian Giles Tillotson and a special screening of the film, Amrita Sher-Gil: The Bridge Builder, directed by Ebrahim Alkazi.The book talks about Amrita Sher-Gil’s journey between the polarities when she remained unacknowledged during her life and considered an icon post her death. Did the Ajanta caves and Gauguin influence Amrita’s works? How was she as a person and as an artist? Was her work in India indeed of unequal quality as often considered to be? In this collection, Karl Khandalavala, G H R Tillotson, K G Subramanyan, and N Iqbal Singh, among others, ponder these and other aspects of Amrita’s short but impactful life dedicated to art. Also Read – ‘Playing Jojo was emotionally exhausting’With Charles Fábri’s fictional account of the travails of a young artist in Lahore in the 1940s carrying an unmistakable resemblance with the influential and avant-garde artist, the volume also includes a piece by Amrita on her evolution as an artist. Accompanied by rare black and white and colour visuals, this book brings together modern and contemporary critiques as well as early writings by past masters that have largely remained inaccessible until now.last_img read more

Chairman vicechairman removed for internal feud

first_imgKolkata: Taking a tough stand against infighting, the Trinamool Congress on Tuesday removed the chairman and vice-chairman of North Dum Dum municipality and announced the names of Subodh Chakraborty as chairman and Lopamudra Dutta Chowdhury as vice-chairman of the civic body.The decision was taken after a high-level meeting at the chamber of state Food minister Jyotipriya Mallick who also happens to be the TMC president of the North 24-Parganas. Senior Trinamool Congress leaders like Saugata Roy, Chandrima Bhattacharjee, Nirmal Ghosh and most importantly 25 councillors of the municipality were also present in the meeting. Also Read – Heavy rain hits traffic, flights”We have removed the chairman and vice-chairman and have appointed new ones after we reached a consensus in the meeting. The parliamentary party of the municipality will hold a meeting every 15 days to keep a stock of the progress of work and at the same time a monitoring committee that has been formed will also hold meetings in presence of senior leaders to keep an eye on the functioning ” Mallick said.It may be mentioned that factional feuds within the TMC had reached its pinnacle in North Dum Dum on May 24 when the vice-chairman of the TMC-run North Dum Dum municipality was assaulted at his office by two contractors allegedly close to chairman Kalyan Kar. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe ruckus inside spilled on to the streets as vice-chairman Nazimul Haq’s supporters blocked roads and railway tracks and damaged police vehicles, bringing traffic in Birati-Nimta area to a halt. Even MP Saugata Roy was mobbed by the protesters when he reached the spot to pacify the crowd.The party had formed a committee under the leadership of Roy to address the issue of internal infighting. The committee had recommended the removal of both the chairman and the vice-chairman for such action which they felt was not commensurate with the party line. The recommendation was ratified in Tuesday’s meeting.last_img read more

Why hangovers get worse as we grow older

first_imgThe next time a hangover hits you hard the morning after a late-night party, look in the mirror to see if your hair is turning white or your hairline is receding.Yes, age is a major factor in the way drinking affects you. Worsening impact of hangovers are a reminder that drinking in moderation would be a better idea, say health experts.“The capacity of our liver to cope with alcohol reduces with age. The alcohol metabolising enzyme reduces and the body fat increases reducing muscle mass, thus increasing the effect of alcohol,” said Dr Rahul Tambe, general physician from Nanavati Super Specialty Hospital in Mumbai in an email. Also Read – ‘Playing Jojo was emotionally exhausting’“Elderly people are often on multiple medication which interferes with alcohol metabolism. Losing weight causes reduced distribution of alcohol in body causing greater intoxication and hangover,” he added.According to Dr Yogesh Batra, senior consultant (gastroenterology) at BLK Super Specialty Hospital in New Delhi, with age, there is an accumulation of substances like acetaldehyde in the liver which are the by-products of alcohol metabolism and are one of the “incriminating agents” responsible for hangovers.  Also Read – Leslie doing new comedy special with Netflix“There is brain degeneration with age and the toxic products tend to hit the brain harder. There is a tendency towards dehydration as the ageing population tends to drink less water which leads to hangovers,” Dr Batra said. Hangover or veisalgia is usually experienced after an alcoholic over-indulgence. The symptoms experienced range from a simple headache to severe nausea, vomiting, giddiness, fatigue and sweating. In some people, it can even lead to anxiety or panic attacks.  Severity of hangover depends on amount of alcohol intake, frequency of heavy drinking and food intake. Is there a cure for hangover?  “Eat more before and after the alcoholic consumption. Besides eating, drinking loads of fluids will also help. Lime water is the best fluid which can be consumed before and after the alcoholic consumption,” advises Dr Deepak Verma, general physician from Columbia Asia Hospital in Ghaziabad. Alcohol consumption can irritate the stomach lining, leading to gastritis. So, food and fluids taken before and after alcoholic consumption help to reduce the gastric irritation, the experts note.Hangover is best dealt with adequate sleep or rest, plenty of liquids and food. “Losing weight leads to even worse hangovers. Since the effective alcohol concentration in the body is going to be more hence those who lose weight should reduce drinking,” says Dr Batra. In the end, preventing a hangover is easy —drink in moderation, space out your drinks, have plenty of water and eat. But then who doesn’t know this?last_img read more