Researchers clear runway for tin-based perovskite solar cells (PhysOrg.com) — As fuel cells are becoming more popular due to their potential use in applications such as hydrogen-powered vehicles, auxiliary power systems, and electronic devices, the need for the precious metal platinum is also increasing. In fuel cells, platinum is often used as the catalyst for oxygen reduction by splitting oxygen molecules into oxygen ions. However, platinum is rare and expensive: in a fuel cell for a typical car, the platinum catalyst costs about $4,000. Now, researchers from the University of Dayton have showed that carbon nanotubes can replace platinum as the catalyst in fuel cells, which could significantly reduce fuel cells’ overall cost. Carbon nanotubes could even have advantages over platinum, since they could be less resistant to corrosion. The Dayton researchers, led by Liming Dai, doped an array of nanotubes with nitrogen (VA-NCNTs) to prevent the carbon from reacting with oxygen and forming carbon monoxide (CO). Without the nitrogen, CO would build up on the surface and shorten the catalyst’s lifetime. With the nitrogen, the nanotubes are more resistant to this carbon monoxide corrosion and have the potential for long-term operation.The researchers have not built a complete prototype of a fuel cell with nitrogen-containing carbon nanotubes, and they have not estimated the cost to produce them. However, since carbon is abundant and cheap compared with platinum, the overall cost of the proposed design would likely be much less expensive. Hopefully, the metal-free catalyst will assist researchers in moving fuel cell technology forward.More information: Kuanping Gong et al. (2009) “Nitrogen-Doped Carbon Nanotube Arrays with High Electrocatalytic Activity for Oxygen Reduction.” Science Vol. 323. no. 5915, p. 753 doi: 10.1126/science.1166510.via: Ecogeek© 2009 PhysOrg.com Researchers from the University of Dayton have showed that carbon nanotubes can replace platinum as the catalyst in fuel cells, which could significantly reduce fuel cells’ overall cost. Citation: Carbon Nanotubes Make Fuel Cells Cheaper (2009, February 9) retrieved 18 August 2019 from https://phys.org/news/2009-02-carbon-nanotubes-fuel-cells-cheaper.html 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.
Sound increases the efficiency of boiling The system will be presented in August at Siggraph 2012, a conference on computer graphics and interactive techniques, in Los Angeles, from August 5 through August 9. Describing their work, the team does acknowledge that research on dynamic BRDF displays have been done in the past. (BRDF stands for “Bidirectional Reflectance Distribution Function,” a four-dimensional function that defines how light is reflected at an opaque surface.) “Their work stands out, they note, in their use of controlling the screen with ultrasonic vibrations. They use a soap film made from a mixture of colloids that make the bubble hard to pop; in fact they explain that it is possible to poke the bubble screen and interact with it. Citation: Display team creates texture-changing bubble screen (w/ Video) (2012, July 1) retrieved 18 August 2019 from https://phys.org/news/2012-07-team-texture-changing-screen-video.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. They wrote about this in a report titled “A Colloidal Display: membrane screen that combines transparency, BRDF and 3D volume.” The authors are Yoichi Ochiai, University of Tokyo, Alexis Oyama, Carnegie Mellon University, and Keisuke Toyoshima, University of Tsukuba. Explore further More information: 96ochiai.ws/colloidaldisplay (Phys.org) — A team from three universities developed what they claim is the world’s thinnest screen from a bubble. They have figured out how to project images on soap film made of special properties and with a technique where images can run flat, textured, or even appear as if they were 3-D. They are using ultrasonic sound waves emitted from speakers to alter the surface. Also, they have found that by using a single projector, the texture of any image can be changed. An object such as a ball can be made to look smooth or rough. Their bubble is not the type of bubble waved away or popped by children at play. © 2012 Phys.Org They point out that the ultrasonic waves and ultra thin membranes combined under their technique can render realistic, distinctive, and vivid on screen imagery. The team is confident that their system can contribute to new and creative opportunities in display engineering and design. After all, interest is easily drawn in a bubble housing an image, where the bubble can be poked without breaking and which permits the person to interact with it, plus textures of images that can be changed on the fly. In the case of museums, it has been suggested that this bubble screen system could be used to display floating planets. There are numerous possibilities for displays for any exhibition events. While a single screen is enough to alter the texture of a 2-D image, multiple screens can be combined for a 3-D effect.
A bumblebee with a tracking marker and ball bearings attached to the bee’s legs to simulate pollen loads. Credit: Andrew Mountcastle Explore further 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 Citation: Study shows bumblebees fly differently depending on the load they are carrying (2015, August 4) retrieved 18 August 2019 from https://phys.org/news/2015-08-bumblebees-differently.html Play A sample flight trial of a bumblebee with a simulated nectar load tracking an oscillating flower in smooth airflow. Credit: Andrew Mountcastle The observations suggest, the team reports, that bumblebees might actually choose between fetching pollen or nectar depending on wind conditions. They next plan to study that theory to see if it pans out. If so, that might have an impact on overall colony fitness, they note, a concern as scientists continue to try to find ways to prevent colony collapse with honeybees. Bees, as most are aware, are pretty good fliers—they are able to keep aloft in various types of weather conditions and do so most often while carrying big loads of pollen or nectar. Pollen, as the researchers note, is carried in the legs, while nectar is carried in a little pouch in the abdomen. Some studies have looked at bee cargo carrying as it relates to survival and reproduction, (they can carry nearly half their weight in pollen and their full weigh in nectar) but none so far have looked at how carrying loads impacts their ability to fly.To learn more, the team mail ordered a package of bumblebees and put several of them, after affixing differing amounts of stand-ins for pollen or nectar, one by one into a miniature wind tunnel where wind and imitation flower targets were varied. In filming the bees with high speed cameras, the team was able to see how the little fliers adapted to changes in wind speed or to the flower being moved—they found that bee flight was more stable when a bee carried a load of pollen, which helped a lot during windy conditions, though there was a very clear trade-off—all that pollen caused a reduction in maneuverability, an impediment when flying in calm air. Bees able to spot which flowers offer best rewards before landing Journal information: Proceedings of the National Academy of Sciences © 2015 Phys.org A bumblebee with a tracking marker and ball bearings attached to the bee’s legs to simulate pollen loads. Credit: Andrew Mountcastle (Phys.org)—A trio of researchers, two with Harvard University the other with the Royal Melbourne Institute of Technology has found while conducting experiments, that bumble flight is impacted by the load it carries, particularly pollen. In their paper published in the Proceedings of the National Academy of Sciences, Andrew Mountcastle, Sridhar Ravi, and Stacey Combes describe bee flight experiments they conducted in their lab and what they found in observing the behavior of the bees. More information: Nectar vs. pollen loading affects the tradeoff between flight stability and maneuverability in bumblebees, Andrew M. Mountcastle, PNAS, DOI: 10.1073/pnas.1506126112AbstractBumblebee foragers spend a significant portion of their lives transporting nectar and pollen, often carrying loads equivalent to more than half their body mass. Whereas nectar is stored in the abdomen near the bee’s center of mass, pollen is carried on the hind legs, farther from the center of mass. We examine how load position changes the rotational moment of inertia in bumblebees and whether this affects their flight maneuverability and/or stability. We applied simulated pollen or nectar loads of equal mass to Bombus impatiens bumblebees and examined flight performance in a wind tunnel under three conditions: flight in unsteady flow, tracking an oscillating flower in smooth flow, and flower tracking in unsteady flow. Using an inertial model, we estimated that carrying a load on the legs rather than in the abdomen increases a bee’s moment of inertia about the roll and yaw axes but not the pitch axis. Consistent with these predictions, we found that bees carrying a load on their legs displayed slower rotations about their roll and yaw axes, regardless of whether these rotations were driven by external perturbations or self-initiated steering maneuvers. This allowed pollen-loaded bees to maintain a more stable body orientation and higher median flight speed in unsteady flow but reduced their performance when tracking a moving flower, supporting the concept of a tradeoff between stability and maneuverability. These results demonstrate that the types of resources collected by bees affect their flight performance and energetics and suggest that wind conditions may influence resource selection. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Journal information: Science More information: Emission of volatile organic compounds from petunia flowers is facilitated by an ABC transporter, Science 30 Jun 2017: Vol. 356, Issue 6345, pp. 1386-1388. science.sciencemag.org/cgi/doi … 1126/science.aan0826AbstractPlants synthesize a diversity of volatile molecules that are important for reproduction and defense, serve as practical products for humans, and influence atmospheric chemistry and climate. Despite progress in deciphering plant volatile biosynthesis, their release from the cell has been poorly understood. The default assumption has been that volatiles passively diffuse out of cells. By characterization of a Petunia hybrida adenosine triphosphate–binding cassette (ABC) transporter, PhABCG1, we demonstrate that passage of volatiles across the plasma membrane relies on active transport. PhABCG1 down-regulation by RNA interference results in decreased emission of volatiles, which accumulate to toxic levels in the plasma membrane. This study provides direct proof of a biologically mediated mechanism of volatile emission. (Phys.org)—A team of researchers at Purdue University in the U.S. and the University of Amsterdam and Université catholique de Louvain in the Netherlands has isolated the gene responsible for producing a protein that aids the release of volatile chemicals in flowering plants. In their paper published in the journal Science, the team describes how they isolated the gene and showed that it was responsible for producing the carrier protein. Franziska Eberl and Jonathan Gershenzon with the Max Planck Institute for Chemical Ecology offer a Perspective piece on the work done by the team in the same journal issue outlining their findings and the implications the work will likely have on the field of plant research. Explore further Credit: CC0 Public Domain Everyone knows that many flowers produce chemicals that make them smell nice—such volatile chemicals are produced to attract pollinators and to repel predators. A lot of research has been done on flowers and their attraction elements and much has been learned, Eberl and Gershenzon note. But until now, one piece of the puzzle was missing—how the volatile chemicals make their way out of the cells in which they are made. The prevailing theory has been that they are simply diffused through cell membranes. But recent work by another team showed that for diffusion to be the only means of escape would require such a high concentration of the chemicals involved that it would kill the plant. So the team with this new effort sought a possible transport system.Because they are used as transport mechanisms by plants in other activities, the researchers looked at adenosine 59-triphosphate (ATP)–binding cassette transporters in petunias. More specifically, they looked for transcriptomes for the RNAs that encode them. The team reports that they found one such sequence in the gene PhABCG1. Suspecting that it was responsible for causing the production of proteins that could carry the volatile chemicals through cell membranes, they disabled the gene in some of the flowers and found that emission of the volatile chemicals decreased by approximately 50 percent. At the same time, the concentration of the chemicals remaining in the flowers increased dramatically, proving that the team had solved the mystery of how the volatile chemicals are transported and released. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Gene identified that produces protein that helps volatile chemicals be released from flowers (2017, June 30) retrieved 18 August 2019 from https://phys.org/news/2017-06-gene-protein-volatile-chemicals.html © 2017 Phys.org Video: Stop and smell the volatile organic compounds
When an artist says that his works are an extension of who he is, it becomes all the more important to look deeper into the canvas. Artist Narendra Kumar has worked as a teacher of Fine Arts in the faculty of Kendriya Vidyalaya Sangathan for 25 years and a quarter of a decade has given rise to some arresting pieces of work he is exhibiting in the Capital in a show titled Hope and Despair. The paintings exhibited are an inner reflection, a portrayal of expressions, confined and journeying within the four quadrants of expressions, namely anxieties, fears, hopes and despairs. Also Read – ‘Playing Jojo was emotionally exhausting’These paintings can be considered as extensions of Kumar’s personality. It’s an inner reflection, a portrayal of expressions, confined and journeying within the four quadrants of expressions, namely anxieties, fears, hopes and despairs. However, the very multitude of these expression does not mean to be bypassed within simple glimpses, my paintings as pensive pieces of art try for the audience to elevate, to drown, even for a moment, to extraordinary levels of consciousness, in the utmost honesty and genuineness, something like a momentary lapse of concentration from the daily dose of humdrum, he explains. Also Read – Leslie doing new comedy special with Netflix‘Though inconclusive, the broader theme of most of these paintings can be seen as an exploration and transition within three categories – the enchantment and agony of hope, helplessness and self-doubt, ambiguousness of one’s thought, belief and action and complete despair hopelessness or death,’ says the artist. He goes on to explain that hope is nothing but the enormity of our expectations aligned in front of the virgin canvas, the good feeling that this one will be better than the previous one. A feeling that the idea, the concept reflected through this one painting, would eclipse all the previous ones. ‘But amidst the unconformity of the idea there always remains a causal ambiguousness of self-doubt. While at work a thinking crops up about the sense making of the nature of this continuance to paint, harboring another complex dimension of it’s worthiness, questioning the overall significance of pursued artistry. A question, which alleviates itself from the dimensionality of profession, person and definition towards the very purpose of life. These confusions of subliminal attitudes have been expressed in these paintings, questions like ‘Where are they going? How will she go? Providing an intermittent movement towards an unknown region of to satiate the immediate need for an answer,’ Kumar concludes. WHERE: Lalit Kala Akademi, Gallery 8WHEN: On till 27 September, 11am to 7pm
Describing ISIS and al Qaeda as serious security challenges for India, Director of Intelligence Bureau Asif Ibrahim on Sunday said the Indian diaspora has become increasingly vulnerable to elements having allegiance to terror groups.Addressing a conference of DGPs and IGPs, Ibrahim said al Qaeda and ISIS pose serious security challenges for the country if they were not dealt with on priority.“The rapid territorial gain and the influence of caliphate on one hand glamorises the image of the group (ISIS), while on the other it enhances its capability,” he said at the conference attended by Prime Minister Narendra Modi, Home Minister Rajnath Singh and several Chief Ministers. Also Read – Need to understand why law graduate’s natural choice is not legal profession: CJIThe Director of the IB said vulnerable groups and fringe elements from over 80 countries have gone to the region (Iraq-Syria) to participate in the conflict.Ibrahim said a splinter group of the Indian Mujahideen operating in the Af-Pak region has announced its support to the ISIS and to bolster its flagging image, al Qaeda has announced the formation of its Indian sub continent wing specifically targeting India.“We have deliberated the serious issue yesterday and felt that the threat is likely to accentuate as the situation unfolds further in future. Indian diaspora has become increasingly vulnerable in the days to come,” he said. Also Read – Health remains key challenge in India’s development: KovindIbrahim said there is also an imminent danger of Indian youths moving to the conflict zone, emerging as a role model and stressed that such developments, may directly or indirectly, pose a threat to India.“The threat potential is accentuated with some lower rung elements returning from conflict zone,” he said.A youth from Mumbai suburb Kalyan, Arif Majeed, who until now was believed to have been killed while fighting for militant group ISIS in Syria, was arrested on Friday hours after he landed in the metropolis.In May this year, four youths from Kalyan – Shaheen Tanki, Fahad Shaikh and Aman Tandel, besides Arif – had left India to visit holy places in the West Asia, but they disappeared thereafter and since then were suspected to have joined the Sunni extremist group.
Inaugurating a rooftop solar plant here for Khunti court and district collectorate, which is the first in any court across India, he said: “Gandhiji was a big supporter of environment protection. That is why I decided to come here. In a way, I have snatched this opportunity (to inaugurate). I decided to come here because 2nd October is my inspiration. Mahatma Gandhi is my inspiration.” Ahead of the crucial climate change summit in Paris later this year, Modi said India is not to be blamed for the “sin” of environment degradation, but even so will contribute towards containing it. “I want to tell the world on behalf of 125 crore Indians that we have no role in this sin, which has precipitated the environment crisis. Our heritage, culture, ancestors never permitted the exploitation of nature and natural resources.” Also Read – Punjab on alert after release of excess water from Bhakra damThe Prime Minister added: “But irrespective of whoever committed this sin and made this mistake, India will make its contribution for the welfare of the humanity.”Referring to the 180KW Rooftop Solar Photovoltaic system, Modi said if Gujarat or Rajasthan think of solar energy, people will say that it is understandable as they have no coal, but when Jharkhand, which is a rich in coal, does so, it is noticed and the world gets a message from it.Recalling that judges of district courts had once told him that lack of power in court premises hampers the hearing of cases and was a reason behind the pendency and delay in the delivery of justice, Modi said he was shocked to realise that districts courts are deprived of basic amenities like power even after 68 years of independence. Also Read – Union Min doubts ‘vote count’ in Bareilly, seeks probe“The judges of Jharkhand found a solution to it and this court will now run with solar energy. Today, it has become the first district court in the country to run with solar energy. This is the best tribute to Gandhiji. Bapu fought his entire life to get justice for the poor. On his birth anniversary, a court is being connected with solar energy. This is a very good initiative,” he said. The Prime Minister said that like solar energy, the country also needs to focus on energy conservation. “We can’t use up all our resources, we must think about the future,” he said as he exhorted the public to use LED bulbs to reduce their power bills. Modi said the airport at Kochi in Kerala became the first such facility in the country to run on solar energy, while the last railway station on the Vaishno Devi route, too, runs on this source of renewable energy. He said that if
Kolkata: South 24-Parganas police have arrested three dreaded criminals, who had assembled in Sripur area of Sonarpur on late Saturday night.Police have recovered a firearm along with cartridges and some sharp weapons from their possession. Police said they had gathered in the area to chalk out a plan on how to carry out a dacoity in the nearby area. The district police had information that some dreaded criminals might visit the place to carry out a dacoity in Garia. It was also learnt that some miscreants managed to flee when police caught the other accused. Policemen in plain clothes were waiting at nearby places. They are conducting raids to nab the other culprits. According to a senior police officer in the district, the accused have been involved a number of dacoity incidents. Various other criminal cases are also pending against them at various police stations.
A day after a fire broke out at the Tank Road of Prasad Nagar area on Tuesday evening, police found that the fire broke out not because of a short circuit, instead, some unidentified people purposely set ablaze the readymade garment shops in the area, a senior police official said.According to the police, three brothers suffered severe burn injuries while an old woman died due to the burns at the RML Hospital. The three persons have been identified as Rakesh (42), Suresh (38) and Anand (31). Doctors at the hospital said that Rakesh suffered 75 per cent burns while Suresh and Anand were discharged after being treated. Also Read – Man arrested for making hoax call at IGI airportPolice said that Suresh claimed that he along with his two brothers live in Paschim Vihar with their family. They have five shops at the Tank Road. They suspect that a local goon named Keshav is behind the attack. At the time of the incident, Keshav came to their shop and demanded Rs 1 lakh from them and when Suresh refused, Keshav threatened him of dire consequences and threw a container of oil at them. In a scuffle between Suresh and Keshav, Anand and Rakesh too joined them. Keshav lighted a lighter and threw it at Rakesh and managed to escape from the shop. While trying to save their brother Rakesh, Anand and Suresh suffered burn injuries in their hands. The fire which started at Suresh’s shop spread quickly and 10 shops were gutted.
What is the politics behind the delay in Parliament passing the Goods and Services (GST) Bill? Despite all efforts from the government of the day since 2007, this controversial Bill is the victim of politics. While the BJP blocked it during the UPA regime, it is now the turn of the Congress to do so. Prime Minister Narendra Modi said last week in Parliament that “in a democracy, a consensus is what gives the greatest strength”. Suffice to say, a consensus is eluding the GST. Also Read – Gateway of criminal justiceWhy are the political parties, particularly the Congress playing politics on a crucial Bill? The government is short of the two-thirds majority required to pass the constitutional Bill. Initially, the Modi government thought it could isolate the Congress and mobilise support from the rest. In the Rajya Sabha, the government requires 160+ in a house of 240. The current mobilisation includes NDA (66), TMC (12), BSP (10), JD (U) (12), BJD (6) and perhaps the AIADMK (12). The SP may also come on board, but it has dawned on the government that the bill cannot be passed without the support of the Congress, which has 68 seats. Also Read – Turning a blind eyeThat is why Prime Minister Modi has been making conciliatory noises to the Congress party since the beginning of the Winter Session. It is perhaps the Bihar poll setback, pending Bills, and the need to let Parliament run, which made Modi climb down. To woo the Congress, Modi even praised India’s first Prime Minister Jawaharlal Nehru in his 70-minute speech in Lok Sabha. He referred to the speeches of Congress leaders Sonia Gandhi and Ghulam Nabi Azad, besides showing the draft resolution on the Ambedkar debate to the Congress and also accepted the three suggestions made by them. During the current Winter Session, he has been chanting the consensus mantra. The PM went ahead and invited Congress president Sonia Gandhi and former PM Manmohan Singh for tea to resolve the GST. It was the first time Modi has reached out to the Congress since he took over. CPI(M) general secretary Sitaram Yechury, calling it match-fixing, and said, “We have no objections with their meeting, but they should have included everyone”. The government was enthused by the fact that Sonia Gandhi appeared open to suggestions during the meeting while Manmohan Singh has been all for the GST. She reportedly demanded tobacco and alcohol taxes are part of the GST as Congress-ruled states such as Kerala and Karnataka might stand to lose if these products were excluded from their taxation list. The Congress has brought down its key amendments to three from eight, which Rahul Gandhi calls non-negotiable. They are – (1) capping the rate of GST at less than 20 percent, (2) scrapping a proposed state levy and (3) creating an independent mechanism to resolve disputes on revenue sharing between states – although these demands had not been part of the UPA-sponsored original bill. It may be difficult for the government to accept the additional 1 per cent tax as this was specially introduced to compensate manufacturing states like Gujarat, Maharashtra and Tamil Nadu. While the government may not agree to all of them they could find a way to resolve the issue.While politics may have its own reasons, it is the economy which is getting affected. Reserve Bank of India Governor Raghuram Rajan has recently observed that the passage of the GST is crucial for the economy. What the political parties should understand is that delaying the legislation any further will hurt the economy in the long run. It is estimated that the GST could boost the economy by 2.5 percent of the GDP. Also, it will be a good thing as all the different taxes like the service tax, sales tax, value added tax and entertainment tax, will be subsumed under a unified tax regime.The proposed GST is to be levied concurrently by both the Centre and States. Many states are apprehensive that it will lead to a loss of revenue. They want petroleum, alcohol, and tobacco out of the GST as they make up a large part of state revenue. The nine Congress chief ministers have also opposed the GST Bill in its present form. BJP chief ministers from Madhya Pradesh, Chhattisgarh and Karnataka are concerned that GST could erode their revenue base. But other consuming states like West Bengal, Odisha and Uttar Pradesh have been votaries of the GST. The Left parties have given their dissent note to the Parliament committee, which examined the GST Bill. The AIADMK, in its note, demanded keeping petroleum products and tobacco outside the GST regime. Most states also are concerned about the levy of 1 percent additional tax on inter-state movement of goods. The functioning of the GST Council is another concern.Union Finance Minister Arun Jaitley is hopeful of a positive outcome and has been working hard to reach out to various political parties. They should go above politics to get the Bill through. If the GST Bill does not get passed in the Winter Session, the government will miss the April rollout date. For those outside India, to whom Modi has sold the Great India story, if he fails to build a consensus on key reform bills and winter session turns a repeat of the Monsoon Session, he will face tougher days ahead. (The author is a senior political commentator. Views expressed are strictly personal)