Month: <span>August 2019</span>

Vshaped solar cells could lead to better efficiency

first_img A crystal clear step closer to commerical solar cells Explore further “In solar cells,” Peter Peumans tells, “the goal is always higher efficiencies. Higher efficiencies usually mean lower cost.” This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.center_img Citation: V-shaped solar cells could lead to better efficiency (2007, December 19) retrieved 18 August 2019 from As solar cells continue to be more important as renewable energy sources, affordable techniques for producing solar cells will be in demand. Peumans, a scientist at Stanford University, and his colleagues Seung-Bum Rim, Shanbin Zhao, Shawn R. Scully and Michael D. McGehee describe one such technique to increase solar cell efficiency: v-shaped cells. The results of their findings are reported in Applied Physics Letters: “An effective light trapping configuration for thin-film solar cells.”Peumans explains that he and his peers used organic solar cells to develop their technique. Organic solar have an active layer made out of molecules, such as pigments or polymers. They are low-cost and flexible. However, as Peumans points out, “organic solar cells typically have low efficiencies.” A traditionally designed organic solar cell consists of a film layer of the light absorbing material spread on top of some sort of substrate. The Stanford team found that if they took a traditionally designed solar cell and then bent it to form a v-shape, it was possible to significantly increase the efficiency of the cell. “It’s about light management,” Peumans says. “This is a pretty simple solution.”Peumans goes on to explain that most organic solar cells are made on planar substrates. “When the light hits it, there is only one bounce – only once chance for the light to be absorbed.” The v-shape, he continues, creates an environment in which the light can bounce around. “Every time the light bounces, it has a chance to be absorbed into the cell.”Organic solar cells are defined mainly by a “thin film of organic material sandwiched between two electrodes,” Peumans explains. This is what makes them low cost and flexible. For the most part, due to their low efficiency, they are not realistically considered for energy generation on a large scale. However, the technique developed at Stanford has the potential to change that. “We were able to increase the efficiency by 52 percent,” he says. “The same cell generates more electrical power.”Organic solar cells are not the only technology that could make use of this efficiency-boosting technique. “While this works particularly well on organics,” Peumans says, “it can be applied to other thin film solar cell technologies as well.” He explains that they evaluated the potential for increased efficiencies in thin film silicon solar cells. “For many solar cell technologies, it would make sense to adopt this approach.”Peumans says that there is already a company working on this technique, “trying to improve the concept and trying to get even higher efficiency out of it.” He also points out that he and his colleagues performed a cost analysis on their method. “Companies would have to figure it out on a case by case basis,” he concedes, “but the numbers we looked at indicated that you could produce solar modules at a lower cost per installed Watt.”While organic cells would likely need further development to become practical for large-scale electrical power generation uses in grids, the idea of a v-shaped solar cell could be incorporated into existing then film solar cells.“This is potentially a very simple application technique,” Peumans says. “It could be a way to increase the efficiency of different types of thin film solar cells.”Copyright 2007 All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of read more

Distinguishing decoherence in quantum systems

first_img“Over the years, work on Bose-Einstein condensates, known as BEC, have led to more and more interesting phenomena,” Artur Widera tells “This is because they behave according to quantum mechanics, and are fairly large objects. The goal is to use them to explore opportunities in the quantum regime.” Citation: Distinguishing decoherence in quantum systems (2008, April 22) retrieved 18 August 2019 from Study: Atomic contamination similar to that of gemstones serves as a quantum information carrier This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.center_img Widera, a scientist at the Johannes Gutenberg University in Mainz, Germany, believes that he and his colleagues have found a technique that can help understand the spin dynamics of one-dimensional quantum systems. Widera worked with Stefan Trotzky, Patrick Cheinet, Simon Fölling, Fabrice Gerbier and Immanuel Bloch at Johannes Gutenberg, as well as with Vladimir Gritsev, Mikhail D. Lukin and Eugene Demler at Harvard University. The group’s efforts can be seen in Physical Review Letters: “Quantum Spin Dynamics of Mode-Squeezed Luttinger Liquids in Two-Component Atomic Gases.”Because Bose-Einstein condensates are so large (they are comprised of hundreds of thousands of atoms), while still adhering to the rules of quantum physics, many experimentalists use them to test the properties of quantum mechanics. It is thought that such study can advance technology for use in more precise atomic clocks and sensors. Widera, though, points out some of the difficulties encountered by scientists who use BEC to study quantum mechanics. “In experiments, we see that quantum properties somehow decay. We call this decoherence,” he explains. “They do so for two main reasons. The first is technical. It usually means that we have done something wrong. The second reason is due to the interactions between atoms that go on at that level and make our signals look like decoherence. At the same time these interactions can lead to probably the most intriguing phenomena in quantum physics, namely quantum correlations.”The problem, Widera continues, is that “using the decoherence signals, so far we did not have the tools to distinguish between a technical problem and these interactions that might signal something interesting.”In order to solve this problem, Widera and his colleagues introduced a new way to try and distinguish between the different reasons for decoherence in quantum systems. The team took a BEC in its three-dimensional state and then squeezed it down into a one-dimensional trap in order to encourage more interactions. “In solid state physics, we find that there are interesting phenomena in the lower dimensions that are not possible in three dimensions,” Widera explains. “Experimentally, we used, not a single system, but an array of one-dimensional systems.”Widera says that they were able to distinguish between the decoherence caused by interactions in the BEC and by more technical issues. “Additionally, we even saw that quantum fluctuations play a big role, and that they dominate the behavior. This is a fundamental property of one-dimensional quantum systems, which in our experiment could be understood thanks to our colleagues from Harvard.”The next step, though, is to actually try and create and control the interesting interactions and correlations in the BEC. “Now, we’ve been able to see and understand what effects are going on,” Widera points out. “But no one’s been able to control these interactions. This would be the key to reliably create these novel quantum states.” Widera admits that they tried to do so in the experiment, but the attempt was unsuccessful. “There was too much novel physics going on which we had to understand first.”“Right now this work deals with fundamental quantum physics,” Widera says. “Think how it will be when we know how to control these issues.”Copyright 2007 All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of Explore furtherlast_img read more

Researchers say web searches are good predictors of success

first_img Citation: Researchers say web searches are good predictors of success (2010, September 29) retrieved 18 August 2019 from Earlier studies demonstrated that Web searches often reflect real-time statistics, and this led a Yahoo research group to investigate if searches could also be good predictors of trends. They selected dozens of upcoming movies, games and songs and collected data on the number of Web searches made on each, beginning up to six weeks before their release, and then compared this information against the measures of success, such as box office takings and video game sales. They then compared the Web search data with traditional prediction indicators such as movie reviews, production budgets, critics’ ratings, previous ranking on the Billboard chart, and the Hollywood Stock Exchange, which is a futures market for trading box-office takings for future releases.The team, led by Yahoo’s Sharad Goel, also looked at Web searches of flu and colds to see if they were accurate real-time indicators of infection, as compared with data from the Center for Disease Control and Prevention.The results of the investigations, published this week in the Proceedings of the National Academy of Sciences (PNAS) were that Web searches are reasonably accurate at spotting trends, especially for movies and video games, but were generally (but not always) outperformed by more traditional predictors. Search data did outperform traditional predictors in the area of non-sequel video games. The most accurate predictions, however, were obtained by combining traditional data with the Web search information. Yahoo researcher Jake Hofman suggested the accuracy of predictions for new video games was probably due to a lack of data for non-sequel games, with the only information generally available being critics’ reviews, which turned out to be inaccurate as predictors.The search information was also sometimes more accessible than traditional indicators such as production budget information for video games, and provides a decent guide if no other information is available. It is also especially useful at times when there is a sudden change in trends.Goel said information from Web searches will continue to grow and will be an important analysis tool in the future, as long as the information is available from search engines such as Yahoo.Google has also studied Web searches as a predictor, and developed a tool called Google Flu Trends that used search queries for “flu” and “influenza” to predict the rate of illness in different geographic locations. The tool was able to predict the likely number of cases in the US over a week earlier than the Centers for Disease Control and Prevention could. Explore further © 2010 ( — Researchers at Yahoo! have been collecting data on Web searches for movies and games and comparing them with other predictors of success, such as product reviews and production budgets, and have discovered that, while not as accurate as traditional means, adding search data into the mix makes predictions more successful overall.center_img Bing starts powering Yahoo! searches in US More information: Predicting consumer behavior with Web search, Sharad Goel et al., Proceedings of the National Academy of Sciences, Published online before print September 27, 2010, doi:10.1073/pnas.1005962107 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

Robotic hand nearly identical to a human one w Video

first_img(A) and (B) show the DART hand in comparison to a human hand. (C) shows the silicone skin covering the mechanical components. (D) shows the DART hand typing the letter ‘L’ at a computer keyboard. Image credit: Thayer, et al. ©2011 IOP Publishing Ltd. Play The DART hand types “holly jolly.” Video credit: Nicholas Thayer and Shashank Priya. “[The greatest significance of our work is the] optimization of the hand design to reduce the number of motors in order to achieve a similar degree of freedom and range of motion as the human hand,” Priya told “This also allowed us to achieve dimensions that are on par with the human hand. We were also able to program the hand in such a manner that a high typing efficiency can be obtained.”One small difference between the DART hand and the human hand is that each finger in the robotic hand is controlled independently. In the human hand, muscles are sometimes connected at the tendons so they can move joints in more than one finger (which is particularly noticeable with the ring and pinky fingers). The researchers, Nicholas Thayer and Shashank Priya from Virginia Tech in Blacksburg, Virginia, have published their study on the robotic hand in a recent issue of Smart Materials and Structures.The researchers call the hand a dexterous anthropomorphic robotic typing hand, or DART hand, as the main objective was to demonstrate that the hand could type on a computer keyboard. They showed that a single DART hand could type at a rate of 20 words per minute, compared to the average human typing speed of 33 words per minute with two hands. The researchers predict that two DART hands could type at least 30 words per minute. Ultimately, the DART hand could be integrated into a humanoid robot for assisting the elderly or disabled people, performing tasks such as typing, reaching objects, and opening doors.To design the DART hand, the researchers began by investigating the physiology of the human hand, including its musculoskeletal structure, range of motion, and grasp force. The human hand has about 40 muscles that provide 23 degrees of freedom in the hand and wrist. To replicate these muscles, the researchers used servo motors and wires extending throughout the robotic hand, wrist, and forearm. The robotic hand encompassed a total of 19 motors and achieved 19 degrees of freedom. Copyright 2010 All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of Citation: Robotic hand nearly identical to a human one (w/ Video) (2011, February 18) retrieved 18 August 2019 from The robotic hand can be controlled by input text, which comes from either a keyboard or a voice recognition program. When typing, a finger receives a command to position itself above the correct letter on the keyboard. The finger presses the key with a specific force, and the letter is checked for accuracy; if there is a typo, the hand presses the delete key. By moving the forearm and wrist, a single DART hand can type any key on the main part of a keyboard.The DART hand isn’t the first robotic hand to be designed. During the past several years, robotic hands with varying numbers of fingers have been developed for a variety of purposes, from prosthetics to manufacturing. But as far as the researchers know, no robotic hand can accurately type at a keyboard at human speed. When the researchers compared the functional potential of the DART hand to other robotic hands, the DART hand had an overall functional advantage. In addition, the researchers used rapid prototyping to fabricate all the components, significantly reducing the cost, weight, and fabrication time.In the future, the researchers plan to make further improvements to the robotic hand, including covering the mechanical hand in a silicone skin, as well as adding temperature sensors, tactile sensors, and tension sensors for improved force-feedback control. These improvements should give the robotic hand the ability to perform more diverse tasks.“We have already experimented with grasping tasks,” Priya said. “In the current form it is not optimized for grasping, but in our next version there will be enough sensors to provide feedback for controlling the grasping action.” Explore furthercenter_img More information: Nicholas Thayer and Shashank Priya. “Design and implementation of a dexterous anthropomorphic robotic typing (DART) hand.” Smart Mater. Struct. 20 (2011) 035010 (12pp). DOI:10.1088/0964-1726/20/3/035010 PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen Scientists develop ‘clever’ artificial hand 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. ( — When it comes to finding the single best tool for building, digging, grasping, drawing, writing, and many other tasks, nothing beats the human hand. Human hands have evolved over millions of years into four fingers and a thumb that can precisely manipulate a wide variety of objects. In a recent study, researchers have attempted to recreate the human hand by building a biomimetic robotic hand that they have optimized to achieve near-human appearance and performance.last_img read more

Cats versus dogs in the drinking category w video

first_imgImage credit: Biology Letters, doi:10.1098/rsbl.2011.0336 © 2010 Citation: Cats versus dogs in the ‘drinking’ category (w/ video) (2011, May 26) retrieved 18 August 2019 from However, A. W. Crompton and Catherine Musinsky from Harvard University decided they needed to step up on the side of the dogs and discover just how they drink water. In a new study published in Biology Letters, Crompton and Musinsky show that dogs drink in the same fashion as cats, leaving to a draw in the competition. Cats however may win the point for being less messy when they drink.Similar to the study done by Reis and Stocker on cats, Crompton and Musinsky used high-speed video and x-ray video to show just what happens when a dog drinks water. While most people assume that the dog, which curves its tongue to form a spoon of sorts, scoops water into its mouth, this is actually inaccurate. While the dog does scoop its tongue, the water that is trapped in the ‘scoop’ is actually lost when the dog draws its tongue into its mouth. ( — The competition between cat and dog owners has one or the other always looking for an advantage and cat owners thought they had one last year when Pedro Reis and Roman Stocker from MIT discovered that cats used their tongues in a very unique way to dry water into their mouths. While cats drank in this manner, Reis was sure that dogs, which are known for scooping and making a mess, had to drink in a different way. Study reveals the subtle dynamics underpinning how cats drink (w/ Video)last_img read more

Two defining features of quantum mechanics never appear together

first_imgIn the new study, the researchers have attempted to violate both inequalities at the same time, but have found that only one inequality can be violated at once. Their experiment uses entangled photons to generate photonic qutrit-qubit systems (a qubit is a superposition of two states, whereas a qutrit is a superposition of three states). By performing various measurements on these photons, the researchers could violate the inequalities separately, but not at the same time.”The greatest significance of our work is that we provide experimental evidence of the assumption that quantum entanglement and contextuality are intertwined quantum resources,” Peng Xue, a physicist at Southeast University in Nanjing, China, and one of the lead authors of the paper, told Experimental setup demonstrating the contextuality-nonlocality tradeoff in a qubit-qutrit system. Credit: Zhan, et al. ©2016 American Physical Society More information: Xiang Zhan, et al. “Realization of the Contextuality-Nonlocality Tradeoff with a Qubit-Qutrit Photon Pair.” Physical Review Letters. DOI: 10.1103/PhysRevLett.116.090401 The physicists, Xiang Zhan, et al., have published a paper on the nonlocality-contextuality tradeoff in a recent issue of Physical Review Letters. In the everyday world that we observe, an object can only be affected by nearby objects (locality), and when we make a measurement, the outcome does not depend on other independent measurements being made at the same time (noncontextuality).In contrast, the quantum world is nonlocal, as demonstrated by quantum entanglement where two objects can influence each other even when separated by large distances. And in the quantum world, measurements are contextual, so quantum systems do not have predetermined values but instead their values depend on how measurements are made.To show that a quantum system is nonlocal or contextual, physicists have defined inequalities that assume a system is the opposite (local or noncontextual). Then they perform experiments that attempt to violate these inequalities to show that the system is not local or noncontextual. So far, these two types of inequalities have never been tested simultaneously. © 2016 As the physicists explain, the reason for the nonlocality-contextuality tradeoff arises from the fact that both properties have the same root: the assumption of realism, which is the assumption that the physical world exists independent of our observations, and that the act of observation does not change it. Since nonlocality and contextuality can be thought of as two different manifestations of the basic assumption of realism, then one of them can be transformed into the other, but both cannot exist at the same time because they are essentially the same thing. “We think the contextuality-nonlocality monogamy suggests the existence of a quantum resource of which entanglement is just a particular form,” Xue said. “The resource required to violate the noncontextuality inequality and that required to violate the locality inequality are fungible through entanglement. That is, to violate the locality inequality costs entanglement as a resource, while to violate the noncontextuality inequality costs contextuality as a resource. In a quantum system, only one of the two inequalities can be violated because nothing is left to violate the other one.”The researchers hope that the new experiment will open the doors to further exploring the mutual resource in the future, as well as lead to potential applications.”We plan to study contextuality as a resource for experimental quantum information processing, such as for quantum computation,” Xue said. Explore further Journal information: Physical Review Letters Citation: Two defining features of quantum mechanics never appear together (2016, March 21) retrieved 18 August 2019 from Representation of measurements that demonstrate the contextuality-nonlocality tradeoff. Credit: Zhan, et al. ©2016 American Physical Society (—Two of the most important ideas that distinguish the quantum world from the classical one are nonlocality and contextuality. Previously, physicists have theoretically shown that both of these phenomena cannot simultaneously exist in a quantum system, as they are both just different manifestations of a more fundamental concept, the assumption of realism. Now in a new paper, physicists have for the first time experimentally confirmed that these two defining features of quantum mechanics never appear together. Physicists find extreme violation of local realism in quantum hypergraph states 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

When clouds burst

first_imgA recent musical event at ICCR presented a unique blend of classical dance, poetry and music on the Capital stage. The event was held on 5 July was an Indo-American vision conceptualised by Viijayalakshmi, known as one of the most eminent exponent’s of the Mohiniyattam dance form. Viijayalakshmi performed to a new choreographic work, inspired by Sudeep Sen’s critically acclaimed book of poetry called Rain with music by Mac Quayle, a Los Angeles based Grammy nominee for Donna Summer. Also Read – ‘Playing Jojo was emotionally exhausting’The audience got a chance to experience an unique blend of a composition performed through dance, music, and poetry. The composition used Mohiniyattam to interpret and express the feeling of rain. The music included a seamless blend of world music which consisted of Kerala rhythms, Dhrupad, Rabindra Sangeet and other contemporary elements. Last but not the least, the framework was provided by English poet Sudeep Sen, which helped to form an instant connection with the non Indians at the event, making it easier for them to comprehend the performance. Also Read – Leslie doing new comedy special with NetflixVijayalakshmi and Mac Quayle worked very closely to convert this concept into a musical arrangement. Dhrupad has been incorporated into Mohiniyattam for the first time. And the part of the Rabindra Sangeet was sung by Vijayalaxmi herself. Vijayalaxmi personally enjoys and loves English poetry and has been passionate about reading English poetry since her childhood, which she finds inspiring, evocative and multicultural.‘The idea of this composition was to break the cliché of repetition and to think out of the box and this 50 minute routine took bits which express her feelings.’ said Vijayalakshmi. Also there was no plan for a script to be included in this idea, it just evolved.  It was furthered by her collaboration with artistic director Sara Baur-Harding from Los Angeles, who is an artist and a documentary filmmaker. On the whole, the show’s adaptation, the choreography, direction, music design and vocal was by Vijayalakshmi, artistic director- Sara Baur-Harding, music arrangement by Mac Quayle, and poetry and narration by Sudeep Sen. The unique and beautiful tones of the composition left the audience mesmerised and talking about the concept with awe and appreciation.last_img read more

Whos afraid of Honey Singh

first_imgThe musician was here in the Capital for an event where we chatted up with him. Excerpts:Tell us a little about yourself and your background. How did you start off?My real name is Dilin Nair. As the name suggests, I am Malayali by origin but I was brought up in Delhi and the city did have a rub-off or induction effect on me. I am so completely a Dilli Da Munda. As a naughty school kid, I always had the knack and flair for rhyming and I guess this is precisely why rapping comes naturally to me. I started as early as kindergarten when teachers used to utter similar sounding words like bat, mat, cat, rat etc. I got hooked. I had a lot of Punjabi friends as well. Also Read – ‘Playing Jojo was emotionally exhausting’Call it my passion to learn and adapt quickly or whatever, it did not take me long to pick up their language and style of talking. I started writing songs when I was in 11th class but I had to wait till the first year of my college to deliver a performance on stage.What was your first big break?  I had an actor-friend and he was working in a movie called Tamanche and I was asked to write a song for the film. This is how Tamanche Pe Disco happened but then for some reason I could not deliver the song to them. Also Read – Leslie doing new comedy special with NetflixThen I shared the song with Tigmanshu Dhulia who was making Bullet Raja and he liked it instantly. The song became a mega hit and it was my big break indeed. Tamanche is yet to be released and as they say, whatever happens, happens for the good.How would you define your musical philosophy?I do whatever is contemporary and trending. There is no philosophy as such. I wish to entertain people and that’s what I have been doing. Audience look for entertainment, to shun their  blues away and it does give me a kick when they swing to my numbers. What are your comments regarding the recent controversy about you? I was credited for the song Dhup Chik in Fugly and not for Banjaarey that I wrote with Honey Singh some years back. And this isn’t a fair thing to do. Honey even declared that he does not know me and has met me seldom. Both I and Baadshah (another rapper) were a part of Honey’s team.I have appeared in two music videos along with Honey Singh, would he do a video with a stranger? I guess success has made him forget a lot of things. If he starts giving due credit for all the songs that others have written for him, who’d ask for Honey Singh? I guess, this is the reason I have moved on.Tell us about your best tracks?Besides Tamanche Pe Disco, I have done the Puppy song and Whistle Baja in Tiger Shroff’s Heropanti and of course the Dhup Chik in Fugly. These are some of my best songs in the recent past.Not to forget Swag Mera Desi, this song is close to my heart because one can be cool while being desi. Whatever you have heard in rap and hip hop so far is kindergarten, this song is like graduation! What are your suggestions for the newbies in the field?Believe in yourself, do whatever comes to your heart and follow your instincts. Make music your religion and deliver the best that you possibly can. Besides all this, I guess nothing else works. It is like a mantra.How has Delhi reacted to your shows? Delhi is my home city! This place has given a lot to me and its payback time, I guess. I wish to entertain Delhiites to the fullest. This is why I am here.What lies next? A lot so to say! I intend to keep entertaining people for many more years to come. I have recently written and composed a number for Salman Khan’s production Dr Cabbie. There are many other projects lined up but it will be appropriate to talk about them as and when the right time comes.last_img read more

5yearold killed after being hit by speeding van

first_imgKolkata: In a tragic incident, a 5-year-old boy was killed after being hit by a speeding Tata Magic.Police said the victim Subhadip Banerjee (5) was trying to cross the road near Ushagram area of Asansol when the vehicle hit him. Locals rushed the victim to a hospital in Asansol after the incident. The doctors declared him brought dead.The incident took place in Nabinpally area near Ushagram under Asansol South police station. According to police, the victim came to the tea stall owned by his grandfather. Also Read – Heavy rain hits traffic, flightsAn eyewitness told the police that a Tata Magic was running at a high speed along the road when it hit the boy. He also told the police that the wind screen of vehicle was broken before it hit the boy. Police suspect that the vehicle might have been involved in another accident as a result of which the driver was overspeeding. The driver fled the spot along with the vehicle immediately after the accident. The victim received serious injuries on various parts of his body. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe locals staged a protest demonstration immediately after the accident. They alleged that the vehicles often overspeed through the area leading to road accidents. Despite the ‘Safe Drive, Save life’ campaign, the district police has failed to check road accidents due to lack of surveillance. The incident led to traffic congestion in the area for sometime. Senior police officers from the district later reached the spot and brought the situation under control. The agitation was lifted following the intervention of the senior police officers. Traffic movement became normal after intervention. Police are conducting raids to nab the driver. A detailed probe has been initiated in this regard.last_img read more