Physicists found the temperature at which carbon nanotubes become superconductors To be fair, observing a supercurrent through carbon nanotubes is not a new discovery. But past studies, which have used ropes made of single-walled carbon nanotubes (those consisting of just one cylinder rather than several nested cylinders), have only been able to achieve superconductivity by deep-freezing the nanotubes down to about 0.4 degrees Kelvin (K). Such an ultra-low “critical temperature,” as it’s called — just fractions of a degree away from 0 K, the coldest temperature possible — is very difficult to achieve and maintain in a laboratory.“In our study, the nanotubes superconducted at a much more manageable critical temperature of 12 K,” said Aoyama Gakuin University scientist Junji Haruyama. Haruyama is the lead author of the paper describing the work, which appears in the February 10, 2006, online edition of Physical Review Letters. “While 12 K is still extremely cold by everyday standards, it requires far less work to sustain. Also, in terms of potential applications of superconducting nanotubes, such as quantum molecular computing, this higher temperature is far more promising.”The scientists measured the supercurrent through the nanotubes by creating arrays of nano-sized electric “junctions” — very thin conducting layered structures. They began with a layer of aluminum, prepared such that it contained a grid of nanoscale pores. On top of this they deposited a layer of MWNTs, which inserted themselves vertically into the aluminum pores. Finally, they topped the nanotubes with a layer of gold.The group created three of these arrays. By carefully cutting off part of the nanotube layer, they created an array in which the nanotubes were flush with the aluminum surface and another in which the nanotubes jutted out slightly above the surface. For the third array, no cutting was done. As a result, each nanotube remained longer than the depth of each pore, and thus “spilled” over onto the aluminum.These three cases correspond to a different degree of nanotube-gold contact, referred to as “end bonding.” In the first array the nanotubes are only slightly end bonded with the gold, while in the third they are fully end bonded.End bonding turned out to be one important factor affecting the nanotubes’ ability to superconduct. Only the array containing entirely end-bonded MWNTs exhibited superconductivity at 12 K. Because the nanotubes were folded over, the gold could only make contact with the outer shell of each nanotube, rather than also bonding with the inner shells. However, in this third case the gold touched far more nanotube surface area.“We concluded that being entirely end bonded with the gold electrically activated all the shells in each nanotube,” said Haruyama. “In the other two arrays, only some of the shells were activated. This indicates that superconductivity in MWNTs is strongly related to the number of electrically active shells and, by extension, that electric interactions between shells play a large role.”Haruyama and his colleagues are planning several follow-up studies. These include an experiment that will attempt to increase the critical temperature of the nanotubes, as well as an investigation into how coupling neighboring nanotubes in the array’s MWNT layer could affect their superconductivity.Citation: “Superconductivity in Entirely End-Bonded Multiwalled Carbon Nanotubes”, Phys. Rev. Lett. 96, 057001 (2006)By Laura Mgrdichian, Copyright 2006 PhysOrg.com Citation: Improved Superconductivity in Multi-Walled Carbon Nanotubes (2006, March 13) retrieved 18 August 2019 from https://phys.org/news/2006-03-superconductivity-multi-walled-carbon-nanotubes.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. A group of researchers from several institutions in Japan has observed superconductivity — a phenomenon in which electrons flow with no resistance — in billionth-of-a-meter sized cylindrical carbon molecules known as “multi-walled carbon nanotubes.” The nanotubes’ ability to superconduct adds to their many intriguing electrical and physical characteristics. Moreover, it increases the likelihood that carbon nanotubes will one day drastically improve electronics, building materials, and many other products. Explore further
Monthly Archives: August 2019
Citation: Former physicist investigates May 6 flash crash (2010, September 22) retrieved 18 August 2019 from https://phys.org/news/2010-09-physicist.html More information: via: The New York Times Wall Street’s super traders come under fire 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. The daily chart of the Dow during the flash crash. Image credit: Wikipedia. Explore further Gregg Berman, a former particle physicist with 16 years of experience on Wall Street, is working for the Securities and Exchange Commission (S.E.C.) to lead a team of more than 20 investigators to find out what caused the flash crash. Over the past several months, the investigators have gathered and analyzed large amounts of data and interviewed hundreds of companies, and now plan to publish a report of their findings within the next two weeks. Although Berman isn’t revealing details about the results, in an article in The New York Times he says that he found no evidence of a deliberate attempt to manipulate the markets. Instead, the investigators have identified a specific series of events that led up to the crash.“The report will clearly demonstrate how market conditions and events prior to the flash crash led to the extreme price moves,” Berman said, adding that the overall picture may not be as simple and straightforward as many people would like.In the weeks and months after the flash crash, a number of theories have been proposed to explain the volatile activity. One of the first theories was the “fat finger,” in which someone accidentally sold an extremely large order, triggering more selling. Another theory was that the European debt crisis had made the markets volatile, which caused some high-frequency automated trading programs to stop trading, which in turn caused confusion among other computerized programs. Regulators now consider both of these theories to be doubtful. In contrast with these simpler explanations, Berman said that his explanation involves several factors occurring simultaneously. He explained that market participants were doing different things for different reasons, and that the varying “circuit breaker” policies of different exchanges caused a lack of coordination and confusion, all of which played a role in the crash.The results of the report will likely be used by a group of advisers to the S.E.C. and the Commodity Futures Trading Commission to make policy recommendations. The results and subsequent policy changes may also reassure investors, who have withdrawn money from stock mutual funds every week since the flash crash. © 2010 PhysOrg.com (PhysOrg.com) — Ever since the “flash crash” of May 6, 2010, investors have been wondering exactly what happened that Friday afternoon. As stock markets were trending down due to concern about the debt crisis in Greece, the Dow Jones Industrial Average suddenly plunged 600 points in about 5 minutes. Then 20 minutes later, the Dow recovered most of the loss, and finished the day down more than 200 points.
New light shed on old dispute between Einstein and Bohr Quantum mechanics at its heart is the study of the building blocks of the universe – what they are and how they work together to form reality as we are able to interpret it. Its ideas were first developed almost a century ago with such notables as Albert Einstein and Niels Bohr developing theories and debating ideas such as whether particles exist at certain places at certain times, or whether they move around constantly with a probability of being someplace at a given moment. The second idea famously led Bohr to conclude that if that were the case than the universe is indeterminate and at its base probabilistic. Refusing to believe such a possibility could be true, Einstein responded with perhaps his most famous quote that “God does not play dice with the universe.” Now, nearly a century later, modern physicists are still just as divided. In the survey, just 42 percent of respondents agreed with Bohrs’ assertions – the rest were divided among several other theories. Also likely surprising to those outside the physics community, a full 64 percent of those who bothered to respond to the survey said they believe Einstein’s view of the universe “is wrong.”Another idea that appears to still vex the modern physicist is whether quantum objects have the same physical properties as they do when measured. Just over half thought so. Also there is the ongoing argument about the probability of a true quantum computer coming to pass, and if it ever does, when that might happen. The largest number, 42 percent said they believe it will happen 10 to 25 years from now, 30 percent said it would come after that, while just 9 percent said they thought it might happen before then.Based on the results of the survey, it appears Richard Feynman was right when he once responded to a reporter’s question about how well quantum mechanics is understood by saying that “anyone who claims to understand quantum theory is either lying or crazy.” (Phys.org)—A trio of physicists has uploaded a paper to the preprint server arXiv describing the results of a survey passed out to attendees at a physics conference held in 2011: Quantum Physics and the Nature of Reality. The purpose of the survey was to find out how much agreement or disagreement there is in the physics community regarding the most fundamental ideas of quantum mechanics – surprisingly, the results showed that there is still very little consensus among physicists regarding some of its most basic principles. © 2013 Phys.org More information: A Snapshot of Foundational Attitudes Toward Quantum Mechanics, arXiv:1301.1069 [quant-ph] arxiv.org/abs/1301.1069AbstractFoundational investigations in quantum mechanics, both experimental and theoretical, gave birth to the field of quantum information science. Nevertheless, the foundations of quantum mechanics themselves remain hotly debated in the scientific community, and no consensus on essential questions has been reached. Here, we present the results of a poll carried out among 33 participants of a conference on the foundations of quantum mechanics. The participants completed a questionnaire containing 16 multiple-choice questions probing opinions on quantum-foundational issues. Participants included physicists, philosophers, and mathematicians. We describe our findings, identify commonly held views, and determine strong, medium, and weak correlations between the answers. Our study provides a unique snapshot of current views in the field of quantum foundations, as well as an analysis of the relationships between these views. Citation: Survey shows physicists can’t agree on fundamental questions about quantum mechanics (2013, January 23) retrieved 18 August 2019 from https://phys.org/news/2013-01-survey-physicists-fundamental-quantum-mechanics.html Explore further Credit: arXiv:1301.1069 [quant-ph] Journal information: arXiv 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.
The company has its roots in the University of Tokyo’s JSK Laboratory. Interestingly, earlier this year IEEE Spectrum called attention to SCHAFT as a Japanese startup that had announced a breakthrough in motor technology that may bypass the limitations of existing systems. The April article said the company had developed a kind of actuator that may make robotic muscles much stronger. IEEE Spectrum also remarked that the DARPA challenge “will be a great opportunity for SCHAFT to show off its innovative motors. A good performance at the competition would compel the next generation of humanoid robots, in Japan and elsewhere, to adopt the technology.” © 2013 Phys.org (Phys.org) —For those wondering who of 16 competing teams would walk away as top performers in the two-day DARPA Robotics Challenge in Florida over the weekend, the suspense is over. SCHAFT, a Japanese company newly acquired by Google, won the most points, 27 out of a possible 32. SCHAFT outscored some formidable big-name contenders such as MIT, Carnegie Mellon, and NASA. IHMC Robotics placed second. Third place went to Tartan Rescue, from Carnegie Mellon University, and fourth place was awarded to a team from the Massachusetts Institute of Technology. The fifth-place went to RoboSimian, designed by NASA’s Jet Propulsion Laboratory. 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. All in all, there were eight top scorers. Team TRACLabs, WRECS (Worcester Polytechnic Institute) and Team TROOPER (Lockheed Martin) were the next three. The eight teams now have the opportunity to continue their work with the help of Defense Advanced Research Projects Agency (DARPA) funding and are to compete in the finals event where one team will net the $2 million prize at the end of 2014. The Finals will require robots to attempt a circuit of consecutive physical tasks with degraded communications between the robots and their operators.DARPA said that the 16 teams at this year’s challenge in Miami represented a mix of government, academic and commercial backgrounds. They were not only from the United States, but also from South Korea and Japan. SCHAFT’s high scores were impressive as the DARPA Robotics Challenge (DRC), established to advance state of the art in humanoid robot competition, is considered as a baseline on the current state of robotics. The event is a marker for assessing the evolution of robots in hazardous first-responder environments, a demonstration of what is so far possible in pushing technologies closer to the point where robots will help out in a range of rescue tasks quickly, efficiently and with minimal human interaction.The robots in the latest challenge had to complete eight tasks including climbing up-and-down a ladder, and removing obstacles and debris. Narito Suzuki, COO at SCHAFT, in a video showing the entry, pointed out their bipedal robot’s strength and stability in navigating its way around. More information: www.theroboticschallenge.org/ Atlas teams head for DARPA Robotics Challenge Citation: SCHAFT team tops scores at DARPA Robotics Challenge (2013, December 23) retrieved 18 August 2019 from https://phys.org/news/2013-12-schaft-team-tops-scores-darpa.html
HAVOC. Credit: NASA Langley Research Center Explore further (Phys.org) —NASA’s Systems Analysis and Concepts Directorate has issued a report outlining a possible way for humans to visit Venus, rather than Mars—by hovering in the atmosphere instead of landing on the surface. The hovering vehicle, which they call a High Altitude Venus Operational Concept (HAVOC), would resemble a blimp with solar panels on top, and would allow people to do research just 50 kilometers above the surface of the planet. Most everyone knows that NASA wants to send people to Mars—that planet also gets most of the press. Mars is attractive because it looks more like Earth and is relatively close to us. The surface of Venus on the other hand, though slightly closer, is not so attractive, with temperatures that can melt lead and atmospheric pressure 92 times that of Earth. There’s also that thick carbon dioxide atmosphere with sulfuric acid clouds, lots of earthquakes, volcanoes going off and terrifying lightning bolts. So, why would anyone rather go to Venus than Mars? Because of far lower radiation and much better solar energy.No one wants to go the surface of Venus, at least not anytime soon, instead, researchers at NASA are looking into the possibility of sending people to hover in the sky above the planet, conducting research in a far less dangerous place than even on the surface of Mars. At 50 kilometers up, an HAVOC would experience just one atmosphere of atmospheric pressure and temperatures averaging just 75 degrees Celsius, with radiation levels equivalent to those in Canada. Astronauts on Mars, on the other hand would experience 40 times the amount of radiation typically faced back here on Earth, which suggests they’d have to live deep underground to survive—a problem that scientists have not yet solved. More information: via IEEE Spectrum The one hitch to floating around Venus, would of course be, figuring out how to get both humans and an HAVOC to the planet, and then for getting the humans back home safely to Earth at some point. The initial plans call for a several missions, building up to the final, with space ships first carrying unmanned vehicles to test the concept of an HAVOC, followed by missions where humans would orbit the planet in space. Next, scientists would have to come up with a feasible design for deploying a floating vehicle able to unfurl, fill itself with gas, and hover for long stretches of time in the sky above the planet. After that, vehicles would have to be designed to work with such a craft, to serve as a ferry between the HAVOC and an orbiting craft, to travel back and forth to Earth, and perhaps between a craft that orbits Earth and the surface. A lot of work, no doubt, but one that seems possible even as more and more space scientists are begining to wonder about the feasibility of sending humans to the surface of Mars. Citation: NASA considers possibilities for manned mission to Venus (2014, December 18) retrieved 18 August 2019 from https://phys.org/news/2014-12-nasa-possibilities-mission-venus.html © 2014 Phys.org Researcher studies possibility of metal snow on Venus 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.
Study finds weird magic ingredient for quantum computing (Phys.org)—Quantum computers hold a special allure, as they offer a way to harness quantum phenomena and put it to use to do things that are impossible for ordinary computers. But as powerful as quantum computers could be, they are also delicate in a way, since they must be shielded from the “noise” in the environment that causes detrimental errors. Making quantum computers that are noise-resistant, or fault-tolerant, is one of the biggest challenges facing their development. Citation: Magic states offer surprisingly low error rates for quantum computing (2015, March 13) retrieved 18 August 2019 from https://phys.org/news/2015-03-magic-states-surprisingly-error-quantum.html Schematic of the protocol for encoding a magic state into the surface code with high fidelity. Circles represent data qubits. Credit: Li. (CC-BY-3.0) © 2015 Phys.org More information: Ying Li. “A magic state’s fidelity can be superior to the operations that created it.” New Journal of Physics. DOI: 10.1088/1367-2630/17/2/023037 Explore further Currently, the leading approach to fault-tolerant quantum computing involves “magic states.” First proposed in 2005 by Sergey Bravyi and Alexei Kitaev, magic states are quantum states that contain an acceptably low level of error. In order to create magic states, physicists take noisy quantum states and use a process called distillation to derive a smaller number of improved, i.e., higher fidelity, states. This process is repeated as many times as necessary until the states reach the target fidelity.Although distillation works, it is a resource-intensive process that requires the majority of a quantum computer’s hardware. In some cases, up to 90% of a quantum computer’s qubits are needed to create magic states, before any real computing can be done.To address this problem, Ying Li, a physicist at the University of Oxford, has looked for a way to minimize the noise in raw magic states (before any distillation) in order to reduce the number of distillation steps required, and in turn reduce the resource cost. In his work, he made a surprising discovery: raw magic states can have a fidelity that is superior to that of the operations that created them. Li’s protocol takes advantage of the fact that qubits are more sensitive to noise when the code distance (which is related to the number of qubits in a row of a lattice) is small, and more stable when the code distance is larger. After an initial encoding step, the protocol enlarges the code distance in order to reduce the error rate.Even though a large number of operations are required to create a single magic state, Li showed that the infidelity of a raw magic state created by the new method is less than half the infidelity of even a single quantum gate used to create it.The new method could lead to significant advantages for fault-tolerant quantum computing. For one type of magic state, for example, the new protocol can reduce the error due to noise by more than 20 times compared to previous protocols. As a result, the number of raw magic states required can then be reduced by a factor of 15. This improvement translates to fewer distillation steps and a dramatic reduction in the hardware needed for quantum computing tasks. Journal information: New Journal 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.
Electron beam-induced etching on diamond using different ratios of hydrogen and oxygen gases to control the anisotropy. With pure oxygen, the etching is isotropic and no patterns are observed. Adding hydrogen gives rise to anisotropic etching, resulting in patterns. Credit: Bishop et al. ©2018 American Chemical Society More information: James Bishop et al. “Deterministic Nanopatterning of Diamond Using Electron Beams.” ACS Nano. DOI: 10.1021/acsnano.8b00354 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. © 2018 Phys.org The ability to etch nanostructures onto the surface of diamond is expected to have a wide variety of potential applications, but so far etching and patterning diamond at the nanoscale has been challenging, as diamond is highly chemically inert (unreactive). In a new study, researchers have investigated a technique in which an electron beam is used for nanopatterning diamond, with the results offering new insight into emerging nanofabrication processes. The researchers, James Bishop et al., at the University of Technology Sydney in Sydney, Australia, have published a paper on the nanopatterning and etching of diamond in a recent issue of ACS Nano.In their work, the researchers investigated a technique called gas-mediated electron beam-induced etching. The method requires no mask or resist layer and uses electron beam irradiation in the presence of reactive gases to directly etch diamond and other materials with a spatial resolution as high as 10 nanometers. It also avoids the residual damage issues associated with physical etch techniques such as focused ion beam or reactive ion etching, enabling etching with minimal damage to the underlying material. So far, most work using this method has demonstrated etching that appears uniform, or isotropic. However, in order to create desired patterns or selectively expose certain crystal planes, it becomes necessary to etch selectively in different orientations, which is called anisotropic etching.Using a combination of experimental and computational techniques, the researchers found that oxygen and hydrogen gases play different roles in the etching process. In particular, oxygen causes rapid, efficient and isotropic etching, while the addition of hydrogen slows down the rate of etching of certain crystal planes more than others, enabling anisotropic etching. Anisotropic etching has long been used with other materials such as silicon and gallium nitride in order to create micro/nano-structures with near perfect symmetry and ultra-smooth crystal planes. This new work highlights a method to potentially achieve similar results with diamond. The researchers found that, as more hydrogen gas is added to the system, patterns emerge whose features are aligned with the crystal directions of the diamond lattice. The scientists explain that these patterns are caused by hydrogen’s preferential passivation of certain crystal planes over others. The researchers also showed that it’s possible to control the anisotropy by controlling the amount of hydrogen, and consequently, to manipulate the geometries of the surface patterns. This enabled the researchers to create a detailed model of the etch kinetics, which should simplify future dry etch nanofabrication processes for diamond and enable fabrication of previously untenable structures.”The most significant outcome of the work is the control over etch anisotropy that it enables,” Bishop told Phys.org. “Isotopic etching is useful for etching arbitrarily shaped structures. Anisotropic etching is useful for creating structures with ultra-smooth surfaces and near-perfect symmetries defined by the kinetics of the anisotropic etch reaction. With electron beam-induced etching using oxygen we can obtain high rate isotropic etching, and by mixing in hydrogen, achieve highly anisotropic etching of diamond.”The ability to controllably etch nanopatterns and selectively expose and smooth certain crystal planes on the surface of diamond has a wide variety of potential applications. Different nanopatterns and nanostructures can, for example, expedite neuron growth on diamond surfaces for biosensing applications, as well as enhance light extraction for photonic applications. Diamond is also being investigated for its possible applications for high-power electronics, electrochemistry, and catalysis, all of which may benefit from a simple, high-resolution nanopatterning method. Citation: New insight into nanopatterning diamond (2018, March 2) retrieved 18 August 2019 from https://phys.org/news/2018-03-insight-nanopatterning-diamond.html Journal information: ACS Nano New etch process developed at the CNST uses argon pulsing to improve silicon etch rate and selectivity 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. © 2018 Science X Network Brown dwarf in a dynamical-tide regime detected by WASP survey Brown dwarfs are intermediate objects between planets and stars. Astronomers generally agree that they are substellar objects occupying the mass range between 13 and 80 Jupiter masses. Although many brown dwarves have been detected to date, such objects existing as companions of other stars are a rare find.Now, a team of researchers led by George Zhou of Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts, reports the finding of a new example of a rare brown dwarf companion orbiting an A-type main-sequence (or A dwarf) star known as HATS-70. The astronomers employed the Hungarian-made Automated Telescope Network-South (HATSouth) to observe HATS-70 and found that this star is transited by some object.Next, the team conducted follow-up photometric and spectroscopic observations of HATS-70 in order to uncover basic parameters of the companion and its host.”We report the discovery of HATS-70b, a transiting brown dwarf at the deuterium burning limit. (…) The transits were first identified by the HATSouth network (Bakos et al. 2013), and confirmed via photometric and spectroscopic follow-up observations that measured the radius and mass of the companion,” the researchers wrote in the paper.According to the study, HATS-70b is about 38 percent larger than Jupiter, has a mass of some 12.9 Jupiter masses and an equilibrium temperature of 2,370 K. The brown dwarf resides in a close-in orbit, separated from the host by only 0.036 AU, with an orbital period of 1.89 days.With an age of about 810 million years, the parent star is nearly two times larger than the sun and has a mass of around 1.78 solar masses. The host has an effective temperature of 7,930 K and a luminosity of approximately 12 solar luminosities. The HATS-70 system is located around 4,260 light years away from the sun.The researchers emphasized that HATS-70b is the first detected brown dwarf companion transiting an A dwarf star. Furthermore, HATS-70b is one of few massive planet or brown dwarf systems with a measured obliquity. The study found that this object, like previously studied massive planets and brown dwarfs, orbits in a low projected-obliquity orbit with 8.9 degrees. Such a low obliquity, when it comes to massive objects, still baffles astronomers.”The low obliquities of these systems is surprising given all brown dwarf and massive planets with obliquities measured orbit stars hotter than the Kraft break. This trend is tentatively inconsistent with dynamically chaotic migration for systems with massive companions, though the stronger tidal influence of these companions makes it difficult to draw conclusions on the primordial obliquity distribution of this population,” the authors of the paper wrote.They added that finding more high-mass companions with obliquities measured, around hot stars could be crucial for determining the origins of close-in orbit brown dwarfs like HATS-70b. Using HATSouth Exoplanet Survey, an international group of astronomers has discovered a low-mass brown dwarf transiting an A-type main-sequence star. The newly detected brown dwarf, designated HATS-70b, is the first such object found around a star of this type. The finding is detailed in a paper published November 16 on arXiv.org. More information: G. Zhou et al. HATS-70b: A 13 Mjup brown dwarf transiting an A star. arXiv:1811.06925 [astro-ph.EP]. arxiv.org/abs/1811.06925 Explore further The unbinned r band HATSouth discovery light curve of HATS-70. Credit: Zhou et al., 2018. Citation: Astronomers detect low-mass brown dwarf around A-type main-sequence star (2018, December 3) retrieved 18 August 2019 from https://phys.org/news/2018-12-astronomers-low-mass-brown-dwarf-a-type.html
(Top) The salt-templated process of synthesizing graphene nanosheets into ink. (Bottom) The ink and printed demonstration. Credit: Wei et al. ©2019 American Chemical Society Journal information: ACS Nano The researchers, led by Jingyu Sun and Zhongfan Liu at Soochow University and the Beijing Graphene Institute, and Ya-yun Li at Shenzhen University, have published a paper on their work in a recent issue of ACS Nano.”Our work realizes the scalable and green synthesis of nitrogen-doped graphene nanosheets on a salt template by direct chemical vapor deposition,” Sun told Phys.org. “This allows us to further explore thus-derived inks in the field of printable energy storage.”As the scientists explain, a key goal in graphene research is the mass production of graphene with high quality and at low cost. Energy-storage applications typically require graphene in powder form, but so far production methods have resulted in powders with a large number of structural defects and chemical impurities, as well as nonuniform layer thickness. This has made it difficult to prepare high-quality graphene inks.In the new paper, the researchers have demonstrated a new method for preparing graphene inks that overcomes these challenges. The method involves growing nitrogen-doped graphene nanosheets over NaCl crystals using direct chemical vapor deposition, which causes molecular fragments of nitrogen and carbon to diffuse on the surface of the NaCl crystals. The researchers chose NaCl due to its natural abundance and low cost, as well as its water solubility. To remove the NaCl, the coated crystals are submerged in water, which causes the NaCl to dissolve and leave behind pure nitrogen-doped graphene cages. In the final step, treating the cages with ultrasound transforms the cages into 2-D nanosheets, each about 5-7 graphite layers thick.The resulting nitrogen-doped graphene nanosheets have relatively few defects and an ideal size (about 5 micrometers in side length) for printing, as larger flakes can block the nozzle. To demonstrate the nanosheets’ effectiveness, the researchers printed a wide variety of 3-D structures using inks based on the graphene sheets. Among their demonstrations, the researchers used the ink as a conductive additive for an electrode material (vanadium nitride) and used the composite ink to print flexible electrodes for supercapacitors with high power density and good cyclic stability. In a second demonstration, the researchers created a composite ink made of the graphene sheets along with binder material (polypropylene) for printing interlayers for Li−S batteries. Compared to batteries with separators made only of the conventional material, those made with the composite material exhibited enhanced conductivity, leading to an overall improvement in battery performance.”In the future, we plan to exploit the direct chemical vapor deposition technique for the mass production of high-quality graphene powders toward emerging printable energy storage applications,” Sun said. Citation: Graphene-based ink may lead to printable energy storage devices (2019, June 19) retrieved 18 August 2019 from https://phys.org/news/2019-06-graphene-based-ink-printable-energy-storage.html Research team develops cost-effective technique for mass production of high-quality graphene © 2019 Science X Network Explore further More information: Nan Wei et al. “Scalable Salt-Templated Synthesis of Nitrogen-Doped Graphene Nanosheets toward Printable Energy Storage.” ACS Nano. DOI: 10.1021/acsnano.9b03157 Researchers have created an ink made of graphene nanosheets, and demonstrated that the ink can be used to print 3-D structures. As the graphene-based ink can be mass-produced in an inexpensive and environmentally friendly manner, the new methods pave the way toward developing a wide variety of printable energy storage devices. 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.
Wills India Fashion Week – Spring Summer 2015 came to close on 12 October. The five-day fashion extravaganza in the Capital witnessed the who’s who of the fashion industry rubbing shoulders with fashion lovers and enthusiasts at Pragati Maidan as more than 55 designers showcased their collection on the ramp and 124 had stalls for buyers at the venue. Day-5 started off with Niharika Pandey, Niket Mishra and Rahul Singh making way for Joy Mitra, Neeta Bhargava, Rehane, Nida Mahmood, Kanika Saluja (Annaikka), Roopa Pemmaraju and Rohit Bal bringing the curtains down with his grand finale collection Gulbagh at Quli Khan’s Tomb. Here’s a look at the day’s offerings…
Kolkata: The lawyers’ strike at the Calcutta High Court ended today after 70 days of cease-work, the longest in the history of the state’s highest judiciary. Three lawyers’ associations had called for the cease-work on February 19, demanding immediate filling up of the vacant posts of judges at the high court to expedite the disposal of pending cases. The corridors of the court were abuzz this morning as hundreds of lawyers and litigants attended the hearings after the prolonged agitation that had affected the justice delivery system in West Bengal. Also Read – Heavy rain hits traffic, flights A total of 2,23,921 cases were pending before the court at the end of March this year, according to official data. The Bar Association, which commands the affiliation of most of the lawyers practising in the high court, called off the cease-work on Saturday, a day after the Centre cleared the appointment of four judges and the chief justice to the court. Justice Jyotirmoy Bhattacharya will take oath as the Chief Justice tomorrow, the office of the Registrar General said. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killed The high court was headed by acting chief justices for over three years, with the exception of three months in between, Bar Association president Uttam Majumdar said. The court has a sanctioned strength of 72 judges, of which 42 posts were vacant when the agitation commenced in February. Three advocates took oath on March 12, raising the strength of sitting judges to 33. The lawyers, however, had extended their strike, seeking recruitment in at least 50 per cent of the sanctioned seats. The Bar Library Club and the Incorporated Law Society have also withdrawn the agitation and resumed work today. In 2002, the lawyers had resorted to a strike for two months to protest a hike in the stamp duty by the West Bengal government.
Kolkata: The Mamata Banerjee government is seeing a huge response to its Rupashree project that was rolled out across the state from April 1 this year. Since its inception, the state government has received nearly 70,000 applications and disbursed more than 47,233 applications under the scheme and the total amount sanctioned has been more than Rs 118 crore.The scheme, a brainchild of Chief Minister Mamata Banerjee, provides a one-time financial assistance of Rs 25,000 to the family of a girl at the time of her marriage, if her family income is less than Rs 1,50,000 per year. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedAs per figures available with the state Women and Child Development & Social Welfare department which is implementing the project, Murshidabad tops the number of applications, disbursements and the amount sanctioned.The figures till July 9 reveal that Murshidabad has received 9,237 applications, disbursed 5,288 and has allocated an amount to the tune of Rs 13.2 crore. 326 applications have been rejected.The second in the list is Purulia that has received 5,870 applications and disbursed 5,183 applications against an amount to the tune of Rs 12.95 crore. However, the number of rejections is very low and stands at only 36. Also Read – Naihati: 10 councillors return to TMC from BJPSouth 24-Parganas district appears third in the list having received 5,460 applications. The number of disbursements is 4,640, with an amount to the tune of Rs 11.6 crore.The number of applications in some districts of North Bengal has been found to be relatively low. Kalimpong has had the lowest number of applications of only 100 and 87 of these have already been disbursed. North Dinajpur has received 316 applications and 166 of these have already been cleared. Jhargram has had a lower number of sanctions. The number of applications that have been received are 1,039, with the disbursement of 223 against an amount of Rs 5.5 lakh.Jhargram has been carved out as a separate district from West Midnapore on April 4, 2017. West Midnapore has received 5,274 applications and has sanctioned an amount of more than Rs 1 crore against disbursement of 4,026 applications.”Districts like Kalimpong and Jhargram have a reasonably lesser area in comparison to most of the districts. So, applications have been less. It is nothing unusual,” a senior official of the department pointed out.It may be mentioned that the state government has allotted Rs 1,500 crore for the project and around 6 lakh families will be getting the benefits of the scheme. More than 2,000 applications on an average are being received everyday.
Pump up your style with palazzosEasy-to-wear and comfy palazzos are perhaps the best alternative to close-fitting denim. Available in various colours and patterns, these pants can be teamed up with casual plain t-shirts, as it adds colour to the overall look. It can be worn at almost every occasion, especially noon.JumpsuitsAfter making headlines in the ‘70s and ‘80s, long jumpsuits are back this season. It’s fashionable to flaunt full-length jumpsuit as one can pull it off at various occasions like movie promotions, launch parties or street shopping. Accenting your style, long jumpsuits look classy as well as casual. Also Read – ‘Playing Jojo was emotionally exhausting’Shirt dresses for allThe trend is back with a bang as now people are spotted wearing shirt dresses at both formal and informal events. Setting a signature fashion statement, these dresses can be worn as a short shirt dress for late-night parties or it can be teamed up with shorts for a more casual look.High-waist pantsHigh-waist pants are one of the hottest fashion items these days. The popular perception that high-waist pants look good only on tall women can be challenged by short women if they have the right figure and attitude. Wearing high-waist pants with a tucked-in shirt elongates your legs and makes you look slim. Also Read – Leslie doing new comedy special with NetflixMidi skirtsMidi skirts are the current rage this season. However, the length of the hemline might make a short girl look shorter. The key is to opt for a high-waisted skirt cinched with a waist belt. This will make your legs look longer. Pair it with wedges to complete your look for the day.LBDThis versatile piece of clothing is a must-have for every working woman. The classic prom dress has reigned in the hearts of women since its origins in the 1920s. It caters to the desire to look good when one is clueless about what to wear during excruciating summers and soggy months.Madras checks rule casual wearStarted with a humble beginning as a handkerchief, the most colourful trend is back to rule the casual wear. Madras prints add up to the summery look and the unisex wear provides comfort to all and also set up a versatile style statement.
Kolkata: West Bengal Chief Minister Mamata Banerjee today wished the Malayalees a happy Onam and hoped that the Keralites would be able to overcome the difficulties caused by the recent floods in the state and witness a good harvest next season. “Wishing my Malayalee brothers and sisters a #HappyOnam, Banerjee wrote on her Twitter handle. “We are sure you will overcome the pain of the destruction caused by the devastating #KeralaFloods and prepare for a bountiful harvest next year,” she added. In the ongoing monsoon, Kerala witnessed severe flooding following unusual heavy rainfall. About 231 people were killed in Kerala since August eight and over 10.40 lakh others are lodged in 2,770 camps across the state, official sources said.
Babies born to mothers exposed to air pollution from traffic sources during pregnancy have an increased risk of developing asthma before the age of five, finds a new study.Exposure to air pollution from traffic sources during pregnancy increases the risk of developing asthma during the first five years of life, even in urban areas with relatively low levels of pollution, the findings revealed. Also, children whose mothers lived close to highways during pregnancy had a 25 per cent increased relative risk of developing asthma, the study said. Also Read – ‘Playing Jojo was emotionally exhausting’“Our study results highlight the importance of exposure to pollution while babies are still in the womb. Air pollution from traffic sources increased the risk of developing asthma during early years before children reach school age, even in an urban area with relatively low levels of air pollution,” said Hind Sbihi, from the University of British Columbia in Vancouver, Canada. In addition, children born with a low birth weight were more susceptible to the respiratory effects of air pollution, the study showed. Also Read – Leslie doing new comedy special with NetflixThe risk increased with an increase in levels of nitrogen dioxide and carbon monoxide: two markers of traffic-related air pollution, the researchers said. The study, published in the European Respiratory Journal, looks at the role of variation in air pollution in urban areas and the development of asthma, the researchers said.Over 65,000 Canadian children were included in the study and followed up from birth until the age of 10 years.
Skin ageing is a natural process. However, it gets accelerated due to fast-paced lifestyles, imbalanced diet and exposure to harsh weather conditions. Protect your eyes, keep skin moisturised and more for youthful skin, say experts. It is important to start early and help your body replenish the collagen it is losing with the help of preventative treatments and quality skincare products to maintain healthy looking skin.Here are a few suggestions to maintain youthful skin: Also Read – Add new books to your shelf* Moisturise your skin: Look for a herbal day cream that consists of SPF and Edelweiss plant stem cell extract which is known for having antioxidant, anti-ageing and skin conditioning properties. The cream should provide intense hydration, be fast-absorbing and able to re-plump skin.* Follow a healthy diet: An imbalanced diet not only affects your health but also your skin. Therefore, it is important to consume foods that encourage healthy skin renewal. A diet comprising high-vitamin foods such as fruits, salads and natural juices are rich in anti-oxidants that help provide moisturisation and maintain naturally glowing skin. Also Read – Over 2 hours screen time daily will make your kids impulsive* Add a night cream to your skin care regimen: During the night time, skin cell production doubles and skin layers are renewed. While sufficient sleep is the key to flawless skin, enhance this process with an herbal night cream consisting of botanical extracts, by applying it right before sleeping. Night creams work overnight to provide intense hydration making your skin visibly youthful.* Protect your eyes: The area around your eyes is sensitive and most susceptible to developing the first signs of ageing. Use a herbal under eye cream packed with Edelweiss plant stem cells, which will soothe tired eyes. The cream would help gently nourish and hydrate the tender skin around your eyes.* Take a break: Today’s fast-paced life and increased stress levels lead to emotional as well as physical distress. Dull skin, fine lines and wrinkles are signs of ageing that are accelerated due to stress. Indulging in a calming activity such as yoga or meditation can help detoxify your body, balance hormone levels and relieve you of stress.
The festive season is just a couple of days away, and it will bring along a lot of travel and parties, which can disturb sleep pattern. Ensure you get your dose of sound sleep. Experts suggest tips that can help you get through all the disruption at this time of the year with everyone feeling fresh and well-rested:-Carry your own pillow while travelling: If you are travelling to your relative’s place or a new place during the festive holidays, chances are you may not feel comfortable sleeping on someone else’s bed or a couch. Sometimes it could even be an inappropriate pillow that can cause pain in the neck. Also Read – Add new books to your shelfWhile you may not be able to do much about it but you can definitely avoid such circumstances by carrying your own height-adjustable memory foam pillow. These advanced technology pillows take the shape of your neck and also aligns it perfectly with your spinal cord giving you restful sleep and helping you wake up fresh even in unfamiliar spaces.-Splurge on a high-quality sleep inducing mattress: After a tiring day of pandal hopping and meeting your friends and family, you all might be yearning for a good sleep at the end of the day when you hit the bed. In that case, you must splurge on a well-designed, comfortable, and orthopaedic foam mattress that guarantees hours of blissful sleep. Also Read – Over 2 hours screen time daily will make your kids impulsive-Ditch the card games and enjoy the outdoors: Indian festivities are mostly about house parties and chilling with your friends over drinks and food. While they are good for our taste buds, they are detrimental to our health and sleep, resulting in hung-over mornings and lazy days. Why spoil the festive season this way? Instead, plan outdoor events in the daylight like game sessions, outdoor sports, pool brunches, etc that will help keep your daily rhythm in sync and let you end the day with a quality and rejuvenating sleep. -Watch what you are eating and drinking: During festival season, we are unable to control our temptation for sumptuous delicacies. The heavy food and the excuse of drinking at night with friends, impacts our sleep.-Follow basic sleep hygiene: Following basic sleep hygiene is imperative for good quality sleep. Focus on simple things like keeping your bedroom at a comfortable temperature, cutting exposure to bright lights a few hours before sleeping, keeping your hands and feet warm, sleeping a dark and silent room in order to induce sleep.
The swaggering star who for much of his career seemed to be having as much fun making movies as audiences did watching them, died of cardiac arrest in his Florida home on September 6, 2018. He was 82. Memories and tributes pour in from those who worked with Reynolds and were close to the actor, who was No. 1 at the box office for a time in the 1970s.In his autobiography, he said, “I was Number One at the box office five years in a row, which I don’t think anybody has done since. In 1978, I had four movies at once playing nationwide. If I met you then, I’m sorry.”Reynolds in April 2011. Photo by Photobra CC BY SA 3.0Sally Field, who had a relationship with Reynolds for five years, said in a statement, “There are times in your life that are so indelible, they never fade away. They stay alive, even 40 years later. My years with Burt never leave my mind. He will be in my history and my heart, for as long as I live. Rest, Buddy.”Sally Field in 2012. Photo by MingleMediaTVNetwork CC BY-SA 2.0Reynolds said in interviews that Field was “the love of my life.” He married and divorced twice, to Judy Carne and to Loni Anderson.“He was a trailblazer. He showed the way to transition from being an athlete to being the highest paid actor, and he always inspired me,” said Arnold Schwarzenegger.Reynolds and Loni Anderson at the 43rd Primetime Emmy Awards. Photo by Alan Light CC BY 2.0Singer Dolly Parton, who co-starred with Reynolds in The Best Little Whorehouse in Texas, posted a photo of them on the set and wrote, “You will always be my favorite sheriff, rest in peace, my little buddy. I will always love you, Dolly.”Reynolds with the Citrus Queen at Garnet and Gold Football Game, Florida State University, 1963.Actor Patton Oswalt posted, “Burt Reynolds & Clint Eastwood were fired from GUNSMOKE & RAWHIDE at the same time. Burt was told he couldn’t act and Clint his neck was too skinny. In the parking lot, Burt said to Clint, ‘I dunno what you’re gonna do, but I’m gonna take acting lessons.’ ”Photo of Burt Reynolds and John Williams from the Twilight Zone episode The Bard.Many friends made affectionate remarks about Reynolds’ fame as a male sex symbol. He posed for the centerfold of Cosmopolitan magazine in 1972.Ryan Reynolds tweeted “He did it first. And best. And naked.”Reynolds may be best known for his hits like Smoky and the Bandit, The Longest Yard, Hooper, and Semi-Tough, but he came to serious attention in John Boorman’s 1972 thriller Deliverance, which cast Reynolds him as macho outdoorsman Lewis Medlock. Reynolds called it “by far” his best film.Photo of the main cast for the television program Gunsmoke in 1963. From left Amanda Blake (Miss Kitty), James Arness (Matt Dillon), Milburn Stone (Doc Adams), and Burt Reynolds (Quint Asper).“I thought maybe this film is more important in a lot of ways than we’ve given it credit for,” he said in an interview years later.He took pride in doing his own stunts, including going over a waterfall in Deliverance. But in recent years, he said his health suffered because of it.“I went over the falls in Deliverance and I hit a rock and cracked my tailbone,” Reynolds said in an interview. “I tell everyone I was a 31-year-old guy in great shape before I went over the falls.”Publicity photo of Burt Reynolds from the television program Dan August.In a story in Business Insider published two years ago, Reynolds said he wished he let his longtime stuntman, Hal Needham, step in a few more times.“When it’s cold and I’m limping around I think, ‘Why didn’t I let Hal make some money and I just sit down?’ ” Reynolds said. “But you can’t go back.”In 1996, the year before he made an award-winning comeback in Boogie Nights, Reynolds declared bankruptcy.Read another story from us: “Bohemian Rhapsody” – The Long Road to Freddie Mercury Hitting the Big ScreenHe told Vanity Fair, “I’ve lost more money than is possible because I just haven’t watched it. I’ve still done well in terms of owning property and things like that. But I haven’t been somebody who’s been smart about his money. There are a couple of actors who are quite brilliant with the way they’ve handled their money… But they’re not very good actors.”Nancy Bilyeau, a former staff editor at Entertainment Weekly, Rolling Stone, and InStyle, has written a trilogy of historical thrillers for Touchstone Books. For more information, go to www.nancybilyeau.com.
Easter Island is home to 887 monolithic carvings, called moai statues. The moai were built by the Rapa Nui, who were native to the island, somewhere between the years 1400-1650.The largest of the moai weigh up to 86 tons and can be as much as 30 feet tall, although the average size is about half that big, according to Easter Island Travel.The statues are made from volcanic tuff, which is partially fused and cemented volcanic ash, which means it’s fairly easy to shape, but also extremely heavy.Moai statues on Easter Island.It was quarried up the slope of the extinct volcano on the island.It’s assumed that the statues were mostly carved while lying flat on their backs, with the backs only finished when the statue was complete and set upright.There are around 1,000 statues on the island.When the statues were finished, islanders would place them around the island.There are some theories suggesting that they were moved to their final resting places using platforms rolled on logs, but other theories suggest that the finished works could have been rocked and “walked” to their final positions, using just manpower and rope.Rano Raraku Quarry is the site on the side of a dormant volcano, where all the moai on the island were carved. It was a working quarry all the way to the early 18th century. 397 moai still remain on the site at various stages of completion.Many of the statues were first thought to just be enormous heads or head-and-shoulders busts, but research shows they are far more than that.First and foremost, archaeologists have discovered that the statues that appeared to be just heads are actually attached to bodies, according to Forbes.Over the centuries since the statues were erected, sediment and rocks from upslope have slowly buried the statues, leaving only the heads visible.Moai in Rapa Nui National Park on the slopes of Rano Raruku volcano on Easter Island, Chile.A group of archaeologists from UCLA started the Easter Island Project, and have been excavating the buried forms.That may explain how the statues came to be, but why did they end up placed where they did?Mysterious Easter Island monumentsNewsweek reported that another group of researchers, headed by anthropologist Carl Lipo, is answering that question. Lipo has been studying the Rapa Nui and why they disappeared from the island for the past 20 years.One of the issues which sparked his curiosity was how a population managed to survive on an island with so little drinking water. Average rainfall for the island is only about 48 inches a year, and there aren’t a lot of springs or other freshwater sources.Lipo and his colleagues began doing field studies to try to figure out how the Rapa Nui might have used the brackish groundwater that comes up along coastlines.Rapa Nui Dancers, Easter Island.There were historical accounts that the Rapa Nui drank brackish water, but nothing to indicate where they accessed it.Their surveys found several places where brackish water could be obtained, but the really interesting thing was that the moai statues seemed to be placed where there was water that was fit to drink.It has stood at the east side of Rapa Nui for hundreds of yearsLipo said “The more we looked, the more consistently we saw this pattern. Places without ahu/moai showed no fresh water. The pattern was striking, and surprising in how consistent it was. Even when we find ahu/moai in the interior of the island, we find nearby sources of drinking water. That was a real surprise.”Lipo noted that the issue of why the monoliths had been built has always been a central mystery about the civilization which used to inhabit the island.Moai at Ahu Tongariki by the Rapa Nui people, Easter Island, Eastern Polynesia, Chile.It would be logical to expect that the statues should all be placed in spots where they would be easy to see, especially to outsiders, but that’s not necessarily the case.Using them as markers of vital natural resources, however, helps explain a lot about their placement.It’s his hope that the new insight into the placement of the stones can help scientists unravel more of the mysteries of the statues, but also the culture which created them.Read another story from us: Archaeologists Discover the Oldest Library in GermanyThe Rapa Nui civilization was decimated by the diseases and slave raiding brought by European explorers, but before that, the culture managed to survive for five hundred years in a remote environment with very few natural resources. Lipo would like to be able to further unravel just how they managed to do it.
Free Webinar | Sept 5: Tips and Tools for Making Progress Toward Important Goals Register Now » After years of failed product launches, market-share erosion and amid a potentially disruptive takeover battle, smartphone maker BlackBerry is releasing its inner Chip Diller.Remain calm. All is well.In a letter published on its website and repurposed in newspaper ads around the country, BlackBerry is trying a simple message: “You can continue to count on us.”In its “important message,” Blackberry says it has “substantial cash on hand and a balance sheet that is debt free.” The company also reiterates plans to cut expenses in half.With a gift for understatement, given the company’s high-profile fall from grace, BlackBerry acknowledges “challenging times for us,” but emphasizes it is “making the difficult changes necessary to strengthen BlackBerry.”Related: BlackBerry Founders Consider TakeoverBlackBerry, once known as Research in Motion, virtually owned the smartphone market, with its BlackBerry devices so ubiquitous in business they even spawned repetitive-stress injuries known as “BlackBerry thumbs.” But a failure to respond to the growth of Apple’s iPhone and a series of ho-hum products put a thumb into the eye of the company’s investors. Within a short period, the company went from dominance to irrelevance in the smartphone market.The company does acknowledge its tough environment. “Yes, there is a lot of competition out there and we know that BlackBerry is not for everyone,” the company says. “That’s OK. You have always known that BlackBerry is different, that BlackBerry can set you apart.”Left unsaid is that BlackBerry may not even exist soon. Several entities – including current investor Fairfax Financial and a team lead by co-founders Mike Lazaridis and Douglas Fregin – are considering a buyout. Some of those acquirers are said to be interested in breaking up the company, and unlocking the value in its intellectual property, rather than its products.Smartphone Wars: 5 Things BlackBerry Could Have Done to Stay Competitive 2 min read October 15, 2013 Attend this free webinar and learn how you can maximize efficiency while getting the most critical things done right.