Citation: Robotic mini-quadrotors can now build towers (w/ Video) (2011, January 20) retrieved 18 August 2019 from https://phys.org/news/2011-01-robotic-mini-quadrotors-towers-video.html Explore further The autonomous quadrotors each have a gripper mounted on their underside that can lift either horizontal or vertical components. Once in place in the structure, the components snap together with the aid of magnets, and the quadrotors can jiggle the beams to ensure they are correctly in position. The quadrotors work as a team via a wireless network, and the algorithm determines the order in which they lift and place the structure’s components.Mellinger said the algorithm they have developed can be used to build almost any tower-like structure and the only constraints are the availability of parts and the limited battery life of the quadrotors.A PhysOrg article last year showed the mini-robots performing aerobatics and feats such as flying through windows at different angles. Now that the quadrotors are capable of building structures, this may be a first step towards full-scale autonomous flying robots or large numbers of smaller robots being used eventually for construction of real buildings. This might be especially useful in locations where construction is hazardous for humans, such as in war zones, oil rigs, or on extremely tall skyscrapers. GRASP lab demonstrates quadrotors (w/ Video) © 2010 PhysOrg.com The researchers, led by PhD candidate Daniel Mellinger of the University of Pennsylvania’s General Robotics, Automation, Sensing and Perception (GRASP) laboratory, have developed miniature robotic quadrotors that can grasp and lift almost any object and fly it to where it is needed. Now the team has developed a system of building structures in which the human only needs to select a design and an algorithm then controls the quadrotors to build the structure, working cooperatively as a team. 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. (PhysOrg.com) — Robotics researchers in the US that developed mini-helicopters or quadrotors have now demonstrated them working as a team to build quite complex structures such as towers or walls.
What’s happening at the Fukushima nuclear power plant. Video credit: Reuters. Japan’s cooling problemsWhen the earthquake struck Japan, three of the six reactors (Reactors 4, 5, and 6) at the Fukushima power plant were already off for routine inspections. Earthquake tremors triggered the automatic shutdown of the other three reactors, Reactors 1, 2, and 3 (along with eight other nuclear reactors at other power plants). To stop the chain reaction, control rods that absorb neutrons were inserted in between the fuel rods. But the fuel rods are still hot, since radioactive byproducts of past fission reactions continue to produce heat. When the earthquake tore down the power lines, the plant’s main cooling system stopped working. As a backup measure, diesel generators turned on to spray the fuel rods with coolant. But the tsunami that occurred shortly after the earthquake was larger than the plant’s designers had anticipated, and water flowed over the retaining wall and into the area with the generators, causing them to fail. The next backup measure for cooling the fuel rods was a battery system, but the batteries lasted only a few hours. Later, technicians brought in mobile generators and also attempted to inject seawater into the nuclear reactors, which makes them permanently unusable but could help prevent a complete meltdown.While the nuclear technicians searched for better cooling options, the water levels continued to decrease, exposing the tops of the fuel rods. Pressure also began building in some of the reactors. So far, at least three explosions have occurred in Reactors 1, 2, and 3. The explosions happened when the fuel rods began to melt and release gases that reacted with the surrounding steam, producing hydrogen. To release some pressure and prevent explosions, technicians vented some of the reactors, which also released some radioactive material into the environment. Officials have said that the pressure in Reactor 2 dropped significantly after the explosion there, suggesting that the explosion breached the steel containment structure – the reactor’s “last resort” for containing leaked radiation. Also, a fire ignited at Reactor 4, thought to be caused by a large pile of spent fuel rods in a pond. Spent fuel rods need to be kept fully submerged in water for cooling, but the lack of water has left some of the rods partially exposed. Smoke from the fire temporarily increased radiation levels around the reactor, so preventing future fires is very important. The Fukushima plant has seven ponds of spent fuel rods from the past few decades. By some estimates, there may be as many as half a million spent fuel rods that are still radioactive and could catch fire if not kept cool. Japanese officials have stated that radiation around the nuclear reactors has risen to the level where it would adversely affect a person’s health. Officials have implemented a 20-km (12-mile)-radius evacuation zone, and have advised people to stay indoors. The US has told its citizens living in the area to stay at least 50 miles away from the power plant. Some people have been taking prophylactic iodine as a safety measure; consuming this non-radioactive iodine before exposure to radioactive iodine can fill a person’s thyroid and hopefully prevent absorption of the radioactive variety. Fortunately, westerly winds have so far blown much of the radioactive material out to sea.Overall, because the extreme events that caused the cooling problems are so rare and unexpected, it’s difficult to predict exactly what will happen next for Japan’s nuclear plants. © 2010 PhysOrg.com (PhysOrg.com) — When working properly, nuclear reactors produce large amounts of heat via nuclear fission reactions. The heat converts the surrounding water into steam, which turns turbines and generates electricity. But if you remove the water, you also remove the most important cooling element in a nuclear reactor and open up the possibility for nuclear meltdown. This illustration of a nuclear reactor shows water entering the core and surrounding the fuel rods (vertical red bars). When the water level decreases, the fuel rods begin to heat up and face the risk of melting. Image from video below. A handful of nuclear meltdowns of varying degrees of severity have occurred since the 1950s, when researchers began building and testing nuclear reactors. The most serious instance happened in 1986 in Chernobyl, Ukraine. Plagued by design flaws and operator errors, the plant experienced fires, explosions, and radiation leakage. As a result, 30 people died of acute radiation syndrome, and thousands of cases of fatal cancers and birth defects have been reported in the following years. Today, limited access is allowed inside a 30-km (19-mile) exclusion zone surrounding the area. By comparison, the Three Mile Island accident in Harrisburg, Pennsylvania, was much less serious. In 1979, a minor cooling system malfunction led to a series of events that caused a partial meltdown that damaged one of the reactors. However, very little radiation was released into the environment due to the surrounding primary containment vessel. Although the accident caused public concern, no deaths or adverse health effects have been officially attributed to the meltdown. In Japan, the current nuclear crisis at the Fukushima Daiichi power plant lies somewhere in between Three Mile Island and Chernobyl, according to recent news reports. Last Friday’s 9.0-magnitude earthquake and 10-meter (33-foot) tsunami waves that traveled up to 10 km (6 miles) inland overpowered several of the plant’s safety measures. Although employees at the plant have been risking their lives to try to keep the reactors cool, the chance of a serious meltdown seems to be increasing. Inside a reactorInside the core of a nuclear reactor are thousands of long, thin fuel rods made of zirconium alloy that contain uranium. When a reactor is turned on, the uranium nuclei undergo nuclear fission, splitting into lighter nuclei and producing heat and neutrons. The neutrons can create a self-sustaining chain reaction by causing nearby uranium nuclei to split, too. Fresh water flows around the fuel rods, keeping the fuel rods from overheating and also producing steam for a turbine. Explore further But if not enough water flows into the reactor’s core, the fuel rods will boil the water away faster than it can be replaced, and the water level will decrease. Even when the reactor is turned off so nuclear reactions no longer occur, the fuel rods remain extremely radioactive and hot and need to be cooled by water for an extended period of time. Without enough water, the fuel rods get so hot that they melt. If they begin to melt the nuclear reactor core and the steel containment vessel, and release radiation into the environment, nuclear meltdown occurs. More information: via: IEEE Spectrum, The Wall Street Journal, Scientific American, and National Geographic 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: How does a nuclear meltdown work? (w/ Video) (2011, March 17) retrieved 18 August 2019 from https://phys.org/news/2011-03-nuclear-meltdown-video.html Japan worst-case scenario unlikely to cause catastrophic radiation release: expert
Journal information: Nature Geoscience Double O Arch storm composite, Devil’s Garden, Arches National Park, Utah, USA. Credit: Michael Atman Delicate Arch, Arches National Park, Utah, USA. Credit: Jaroslav Soukup The team found that when pressure was applied from above to different parts of a cube, and artificial cracks and other perturbations were also introduced to the sandstone, it led to the development of interesting and unique shapes when subjected to simulated erosion. The researchers believe this same action applies to sandstone in its natural state, and accounts for the remarkable shapes that have left those beholding them wondering how they could have formed and then withstood the ravages of wind and rain—it’s because their columns have been made strong enough to withstand further weathering. © 2014 Phys.org Image: Curiosity Mars rover beside sandstone target ‘Windjana’ (Phys.org) —A team of researchers with members from facilities in the Czech Republic and one from the U.S. has discovered the mechanism by which unique sandstone landforms take shape. In their paper published in Nature Geoscience, the team describes how their studies of sandstone in their lab led to insights about how both gravity and erosion contribute to the creation of such unique structures as Delicate Arch at Arches National Park in Utah. Chris Paola of the University of Minnesota offers a News & Views piece on the research done by the team in the same journal issue. Explore further For many years, scientists have assumed it was wind and rain along with freezing and thawing that accounted for uniquely shaped sandstone landforms—they occur in many places and generally cause those who see them to take a second—or third look. Many believed they came about because some of the rock was just naturally harder than other parts. The results were sometimes awe inspiring structures that at times appeared to defy gravity. But now, new research suggests that it’s actually gravity that allows the structures to form in the first place.Curious as to the real mechanism by which sandstone landforms take shape, the researchers took several samples into their lab and subjected them to intense scrutiny—after cutting the samples into cubes, they used pressure plates to simulate the loads of real structures while also subjecting them to simulated wind and rain. As the cubes were deformed, close inspection revealed that in the parts of the sandstone subjected to direct pressure (simulated gravity) individual grains tended to lock together creating sections of stone that were more resilient to wind and rain. That led to the creation of pillars within the sandstone that stood strong as the grains around them were swept away. As more free grains were swept away, more pressure was exerted on the column causing the grains in them to lock even tighter. More information: Sandstone landforms shaped by negative feedback between stress and erosion, Nature Geoscience (2014) DOI: 10.1038/ngeo2209AbstractWeathering and erosion of sandstone produces unique landforms1, 2 such as arches, alcoves, pedestal rocks and pillars. Gravity-induced stresses have been assumed to not play a role in landform preservation3 and to instead increase weathering rates4, 5. Here we show that increased stress within a landform as a result of vertical loading reduces weathering and erosion rates, using laboratory experiments and numerical modelling. We find that when a cube of locked sand exposed to weathering and erosion processes is experimentally subjected to a sufficiently low vertical stress, the vertical sides of the cube progressively disintegrate into individual grains. As the cross-sectional area under the loading decreases, the vertical stress increases until a critical value is reached. At this threshold, fabric interlocking of sand grains causes the granular sediment to behave like a strong, rock-like material, and the remaining load-bearing pillar or pedestal landform is resistant to further erosion. Our experiments are able to reproduce other natural shapes including arches, alcoves and multiple pillars when planar discontinuities, such as bedding planes or fractures, are present. Numerical modelling demonstrates that the stress field is modified by discontinuities to make a variety of shapes stable under fabric interlocking, owing to the negative feedback between stress and erosion. We conclude that the stress field is the primary control of the shape evolution of sandstone landforms. Citation: Researchers figure out how oddly shaped sandstone landform structures come about (2014, July 21) retrieved 18 August 2019 from https://phys.org/news/2014-07-figure-oddly-sandstone-landform.html Rock pillars, together with rock arches, alcoves and pedestal rocks are decorating sandstone landscape with underlining intricate concept design. Physical and numerical modelling, and field observations of locked sands and sandstone formations reveal aspects of the natural self-organizing engineering. Cueva Colibri – Sistema Brewer, Churí tepui, Venezuela. Credit: Libor Lanik 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.
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: Atmospheric Chemistry and Physics Explore further © 2015 Phys.org A group of 17 scientists with varied backgrounds, including noted climatologist James Hansen has written a paper describing a scenario where the world’s oceans rise much faster than other models have predicted—they have uploaded it to Atmospheric Chemistry and Physics—an open access site created to allow for public peer review of researcher ideas. Citation: New paper by prominent scientists suggests ocean levels will rise much faster than predicted (2015, July 24) retrieved 18 August 2019 from https://phys.org/news/2015-07-paper-prominent-scientists-ocean-faster.html At issue is the degree to which the world’s ocean levels will rise if global atmospheric temperatures rise by 2 C, a standard that has been set as a seemingly acceptable level. The authors argue that such a rise will result in much faster ice melting than other models have suggested, resulting in a rise of the world’s oceans to dangerous levels. They suggest it likely will occur even if atmospheric levels are somehow kept below that benchmark.To come to these conclusions, the team looked at what happened before—back during the Eemian period (prior to the last Ice Age), when atmospheric temperatures were approximately 1 C warmer than they are now. They found that ocean levels were higher than they should have been based on modern models. That finding sent them looking for an explanation—after much work they came up with the idea that a small amount of atmospheric warming led to a small amount of sheet ice melt, which led to a change in ocean current patterns, which created a feedback loop—the more the ice sheet melted the faster it began to melt due to trapped warm water below. They conclude that adhering to the 2 C rise will lead to a very dangerous situation, where coastal areas and island countries will face dire consequences.The paper has already been met with some criticism by other climatologists, though most appear to agree that politicians voting on an acceptable degree of atmospheric rise is likely not in the world’s best interest. Also, it appears, because the paper is addressed to policymakers, that the researchers are hoping their work will cause more than just a change in the standards that have been set—that it might also wake the human race to the cataclysmic changes that really are coming and cause us to change our ways before it is too late—if it is not already. More information: Atmos. Chem. Phys. Discuss., 15, 20059-20179, 2015 DOI: 10.5194/acpd-15-20059-2015 Global sea levels have risen six meters or more with just slight global warming
My son is 29. I think he’s gay. He’s avoiding marriage nor do I ever see him with any girl! How do I find out the truth?Sarita Verma, PatnaAttraction for same sex is there from the days of the Mahabharat. First of all, please do not treat him as a paitent or some sort of a criminal. I have friends from all the walks of life, some of them are gays. So what?! They are super successful and happy in life. I think all mothers want that from their children that they stay happy. Talk to him. Confront and but take it easy! It could also be that he’s focussing on career and hence neglecting marriage. Don’t hitch him up with a girl and ruin both their lives or jump to conclusions too fast. Observe and have a constructive confrontation with your son! Cheer up! Also Read – ‘Playing Jojo was emotionally exhausting’I have seen a couple of blue films and since then I am always thinking of sex. I’m in high school and feel desperate. I don’t have a girlfriend. What can I do?Name withheld, Noida.Don’t worry dear! At your age, this is normal. The hormones rage. But, concentrating on studies is a priority. Don’t neglect that. After just a couple of years you will realise how important degrees and career is. You can always resort to ‘self love’ as masturbation is always the best way to vent out the feelings. I’m sure, very soon you will find your girlfriend but please don’t jump into a physical relationship until you are sure about your partner. Losing your virginity is a pleasure. Preserve it for the right one. Enjoy life and its moments. Also Read – Leslie doing new comedy special with NetflixWe are married and have a kid. How good or bad partner swapping is? We even want to experiment group sex. We both are married, mature and completely in love – this is just for experimentation and to add spice to our sex lives. What do you think?Vinnie, New DelhiWell, I’m nobody to judge the bad or the good of swapping partners. You both are mature adults and you’ll know better what works for you. I’m sure swapping/group sex is a colorful act but can’t really comment on its consequences later. This is the decision of two adults who are participating in it. Just ensure that some momentory pleasures do not lead to permanent damage. As parents you have a responsibilty towards your child. Don’t do anything that will cast a negative shadow in the mind of the young one. Enjoy life. Experiment. But please be extra safe. Life is a long journey and sometimes we neglect consequences while we enjoy the present. My best friends’ parents got divorced. She is shattered. I feel very helpless. We are in 8th standard. How can I help her?Tania Rai, New DelhiJust be extra kind and extra supportive towards her. Help her in whatever way you can. With her homework, taking her out for movies, bringing her over to your place for studies, sleepovers. Your parents can also help by being supportive when you spend time with her.Have a love or life query you cannot find an answer to? Send your questions to – firstname.lastname@example.org
Already an activist for girl’s education in the Swat valley of Pakistan, by writing for BBC Urdu under the pen name of Gul Makai, the events of 9 October, and what transpired subsequently, would change Malala’s life irrevocably. A nominee for the Nobel Peace Prize, for standing up for girl’s education in an area controlled by fundamentalist forces and appearing on the cover of TIME magazine, it is a space far removed from the city of Mingora in Swat Valley. Ghost written by noted journalist, Christina Lamb, Also Read – ‘Playing Jojo was emotionally exhausting’I am Malala is a remarkable story of a family uprooted by lawless terrorism, for a deeply held conviction that resonated with millions around the world.However, as it is an autobiography of a 16-year-old, there are limitations, in terms of what could be narrated about her own life. As a result, Lamb and Malala have had to fill up the pages with the history of Pakistan and the political and religious turmoil that have shaped its history. Malala’s father Ziauddin, is probably the most significant presence in her life. Her strength of character clearly draws inspiration from her father’s socialistic activism in the field of education. Contrasting the two elements, Pakistan’s politico-religious situation and father’s social activism, it is interesting to note that no questions are raised about Malala’s mother, Tor Pekai, who quit school at the age of six and remains an illiterate to this day. Through Malala, we also get close to the heart of Pakistan’s troubles. 20 years after partition, the Wali of the Swat Valley renounced his power and ceded with Pakistan. ‘So I was born a proud daughter of Pakistan,’ she writes, ‘though like all Swatis I thought of myself first as a Swati and Pashtun, before Pakistani.’ The above statement is reflective of the ethnic fissures that have dominated her homeland, with only the burgeoning power of the Taliban that has provided a distraction to these fissures. The presence of the Taliban has raised the need to redress these ethnic tensions. There is a fear amongst those at home, that her narrative will be subjugated by what some perceive as the ‘colonial west’. However, despite being a vocal critic against the Taliban, she does passionately speak out against America’s drone strike in her province, CIA’s policy of funding jihadists when it suits them and even Raymond Davis, the CIA contractor who caused a diplomatic meltdown between the two countries after shooting two civilians during broad daylight in Lahore.Unfortunately, like most ghost-written autobiographies there is a problem with distinguishing between Malala’s and Lamb’s voices. However, this must not distract us from the articulate nature of Malala’s courage and conviction to stand up for the rights of girl’s education in the face of death.
Doordarshan has started the Sunday telecasts of Lakshaya: Ek Living Planet on DD National. This programme which exhibits various environmental issues will be telecast weekly on Sunday nights at 9:30 pm with multiple repeats.In the first episode of the show, five stories were covered which include The Hospitals of Death- Delhi, The Dwindling Fish Population- Maharashtra, Mitticool The fridge-mud- Rajkot, The Chinh initiative- Environment animation by children, Citizen jourmalist-raw unedited stories from all the four corners of India. Also Read – ‘Playing Jojo was emotionally exhausting’The Hospitals of Death- Delhi dealt with the national capital’s problem of the disposal of Biomedical waste. The story tracks down some of the biggest hospitals in New Delhi and looks into the matter closely to expose the danger and spread this awareness to the citizens.The Dwindling Fish Population –Maharashtra covered the issue of overfishing which together with climate change and human interference has reduced the number of fish catch across the Maharashtra coast. There has been a significant drop which is estimated to be around 55% in some species, according to new data from the Central Marine Fisheries Research Institute. This Lakshaya story talks about the ever expanding population demands of a food source that is fast depleting. Affecting not only the delicate ecological-balance but also the fishermen. Also Read – Leslie doing new comedy special with NetflixMitticool The fridge-mud – Rajkot, the brainchild of Mansukhbhai Prajapati , a Gujarat-based potter who created Mitticool, a fridge that doesn’t use electricity. Lakshaya chronicles the amazing tale of it’s invention, right from 2001, when after the earthquake in Gujarat Prajapati decided to make a fridge that could be afforded by people of the economically week section.The Chinh Initiative – Environment animation by children – Delhi is about an initiative by Meenakshi Vinay Rai to give children a platform to create content for various kinds of mass media that revolves around a theme.The community helps children from various age group and strata of society to come up with ideas and stories that can be shaped into a film through various mediums one being animation. The story looks into how India’s future citizens are creating their own green consciousness. Don’t forget to mark the Sunday nights for more interesting stories.
The 34th Petroleum Sports Promotion Board (PSPB) Inter-Unit Golf Championship was inaugurated recently.The four-day golfing extravaganza is one of the most important tournaments on the amateur calendar. Top ranked amateur players such as Udayan Mane, Manu Gandas, Saquib Ahmed, Trishul Chinnappa, Samarth Dwivedi, Simarjeet Singh, Ankur Chadha and Manav Das were seen in action during the tournament. The tournament also witnessed India’s No 1 lady golfer Gurbani Singh and Viraj Madappa and Piyush Sangwan playing for the Championship. Also Read – ‘Playing Jojo was emotionally exhausting’Some of the prominent players from GAIL who would be vying for the Championship are India’s No 2 lady golfer and reigning Sri Lanka Open Champion Gauri Monga, reigning National Amateur Champion Pratap Atwal and local golfer Jaibir Singh. The tournament began with two-day practice rounds followed by the two-day main event to be played on a stroke play format.Speaking on the occasion, R D Goyal said, ‘GAIL has been taking a number of initiatives to promote sports within the organisation and at the same time, supporting and promoting sports and players outside the organisation as well. Participating in PSPB tournaments is one such important platform.’
Kolkata: The mercury may soar up to 40 degree Celsius in some of the Western districts of the state, while a high level of discomfort may prevail in the city later this week. However, a sudden spell of rain and thunderstorm took the city by surprise on Tuesday evening, which brought down the temperature by a few notches.The Regional Meteorological Centre in Alipore predicted that the people in the city and the adjoining districts may feel a sultry and uncomfortable weather, in the latter half of this week. People in Kolkata and its adjoining areas got a relief from discomfort caused due to the hot and humid condition, following the thundershower. Also Read – Heavy rain hits traffic, flightsThe weather office predicted that the Western districts like Bankura, Birbhum, Burdwan and West Midnapore may touch nearly 40 degree Celsius, later this week. The temperature will soar above normal in Kolkata and other adjoining districts as well. People going out on the streets in the sun have been facing severe discomfort due to excessive heat. The situation will, however, not improve till the advent of Norwester, a weather official said.The thunderstorm on Tuesday struck the city and various parts of North 24-Parganas, South 24-Parganas, Hooghly, Howrah and other districts at around 7.30 pm, with wind blowing at a speed of 50-60 km per hour. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe shower, which might have been triggered by a high-pressure belt over the Bay of Bengal, lasted nearly an hour. While it was more intense in the northern fringes of the city, the central and southern parts received moderate rain.The high-pressure belt provided moisture, which was sucked in by the heated land. Since the temperature has been high in Gangetic Bengal for the past few days, it had paved the way for the thunderstorm, a senior official of the Regional Meteorological Centre said. Shear winds during the hour-long storm, led to the disruption of traffic movement in some parts of the city, due to felling of trees. The traffic movement in various parts was slow due to rain and storm. Trees fell near Fairlie Place and Bosta Potti area of Sovabazar. A truck was completely wrecked after a tree fell on it at Sovabazar. A tree also fell near Park Circus. A lamp post fell near Bijan Setu. A shop was damaged when a tree fell on it near Peerless Hotel. Senior police officers were on roads to manage the traffic.It may be mentioned that window panes of Nabanna were also damaged in the storm. Several floors were affected, including the Disaster Management department.Train services on the Sealdah-Dankuni section were restored at 10.50 pm, while services on the Howrah-Bardhaman chord line section is likely to resume soon.