Explore further When water vapor condenses in a nano-sized space between two surfaces, the liquid behaves more like solid ice than liquid water, even at room temperature. This solidification causes water to exert such a strong friction force that it “acts like a glue,” according to a new study. If you’ve ever thought about ice skating on a dry floor – or anywhere besides a sheet of ice – you can easily imagine how you’d ruin your blades and not get very far. Ice skating – like many processes involving moving parts – requires water acting as a lubricant between the blades and the solid ice, reducing friction and keeping the sliding surfaces apart from each other. Now imagine you’re five nanometers tall and want to go ice skating, or that you want to build a nano-sized sliding element using water as a lubricant. Scientists who have recently been experimenting with tiny moving devices have run into problems due to stiction (static friction) forces between moving parts.“Micro- and nano-electromechanical systems (MEMS and NEMS) have tiny moving parts typically etched out of silicon,” said J. Frenken, coauthor with K. Jinesh of a recent Physical Review Letter, to PhysOrg.com. “Using special tricks such as under-etching, intricate structures can be formed with cogwheels, hinges, bending arms and sliding elements.” However, mechanical systems on the micro and nano scales endure much greater friction than their macroscopic counterparts.“Many of the designs for such miniature devices are useless in practice because the parts either don’t move at all anymore or they move with very high friction, which leads to excessive wear,” said Frenken. “After a short time, this wear destroys the device. One could state that many MEMS devices work in ‘self-destruct’ mode.”Jinesh and Frenken explain that the reason for these lube problems is that, on the nanoscale, water ceases to be wet and slippery and instead becomes solid and sticky. By studying the atomic and molecular details of water and the surfaces sandwiching the water, the scientists found condensed water is immediately converted into ice, acting more like a glue than a lubricant. This finding contrasts previous studies, which suggested that water acts like a lubricant down to the nanoscale.“In many of these MEMS and NEMS structures, there are elements that are either touching each other or close to touching each other,” said Frenken. “At the locations where two objects approach each other within a very small distance, water from the air tends to condense. This capillary condensation strongly pulls the (nearly) touching objects into intimate contact. To avoid friction and wear, these elements need to be lubricated with a liquid that would remain slippery down to the nanoscale – actually, the lubricant should become even more slippery than it is on a macroscopic scale.” Keep Cool to Reduce Friction,” Suggests a New Study of Nanoscale Water Condensation 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. At a high enough humidity, water vapor condenses in the tiny region between two surfaces (here, a tungsten tip of a friction force microscope and a graphite surface). Scientists have found that – unlike on the macro scale – the “liquid” acts more akin to a glue-like solid at room temperature, creating excessive friction that disables many tiny mechanical devices. Image Credit: J. Frenken and K. Jinesh. In their experiment, the scientists built a friction force microscope, which consists of a hydrophilic tungsten tip scanning back and forth across a hydrophobic graphite surface. In extremely dry conditions, the tip demonstrated expected “stick-slip motion,” meaning it would generally move evenly, while occasionally slipping ahead at regular intervals.At higher humidities (relative humidity greater than 10%), however, the scientists did not observe this motion due to water vapor condensing in the capillary between the tip and surface. The water exerts an elastic force on the tip, and as the tip moves, the water stays connected with it, appearing to stretch across the surface. (See above image.)The static stress and regular structure of the condensate makes the scientists conclude that the condensate acts like a solid. The team observed the tip “write” a stripe of water up to 250 nanometers, which lasted for up to two seconds and beyond the point where the tip scans above the condensate.“Although in many cases, water acting as a glue on the nanoscale is a nuisance, there are also situations where one can take advantage of the stickiness on this small scale,” said Frenken. “On a macroscopic scale, we all know how dental prostheses that can stay in place via the action of bridging water. In this case, however, the water is still completely liquid because of the thickness of the water layers. In the laboratory, we often use capillary condensation to pick up light objects, simply touching a small object with a thin wire, instead of using tweezers. A capillary neck forms between the object and the wire, gluing the two together.” This “nuisance,” then, may lead to more useful applications, in addition to the problem it identified.Citation: Jinesh, K. B. and Frenken, J. W. M. Capillary Condensation in Atomic Scale Friction: How Water Acts like a Glue. Physical Review Letters. 96, 166103 (2006).By Lisa Zyga, Copyright 2006 PhysOrg.com Citation: Scientists discover water is sticky on a small scale (2006, May 8) retrieved 18 August 2019 from https://phys.org/news/2006-05-scientists-sticky-small-scale.html
(PhysOrg.com) — By demonstrating how a single artificial atom can be used to amplify electromagnetic waves, physicists from Japan are opening up new possibilities for quantum amplifiers, which can be used in a variety of electronic and optical applications. Copyright 2010 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. More information: O.V. Astafiev, et al. “Ultimate On-Chip Quantum Amplifier.” Physical Review Letters 104, 183603 (2010). Doi:10.1103/PhysRevLett.104.183603 Explore further From a classical laser to a ‘quantum laser’ Quantum amplification by an artificial atom. Part (a) shows a sketch of a three-level artificial atom in which population inversion can be created by pumping the atom from the ground state to the second excited state. Part (b) shows the spectroscopy of the three-level atom. 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: Physicists build quantum amplifier with single artificial atom (2010, May 25) retrieved 18 August 2019 from https://phys.org/news/2010-05-physicists-quantum-amplifier-artificial-atom.html As a device that uses quantum effects to amplify a signal, a quantum amplifier comes in many different forms. Perhaps the most well-known example is the laser, which uses the process of stimulated emission to emit photons from optically stimulated atoms. Like most quantum amplifiers, lasers use intra-atomic transitions with many atoms (or molecules) to achieve signal amplification, and the transition frequencies are not easily tunable.One way to realize a quantum amplifier that is tunable and fully controllable is to create a system that uses only a single atom or molecule. However, single-atom quantum amplifiers have so far been very difficult to realize due to the fact that natural atoms can only be weakly coupled to the electromagnetic waves that they must amplify. Now, researchers O.V. Astafiev and coauthors from NEC Nano Electronics Research Laboratories and RIKEN Advanced Science Institute, both in Ibaraki, Japan, have found a way to overcome this difficulty. In their new study, the researchers have demonstrated how a single artificial atom can be strongly coupled to the electromagnetic modes of open one-dimensional space, resulting in tunable and controllable electromagnetic wave amplification. The quantum amplification is based on the ability to pump the three-state artificial atom from its ground state to the higher of its two excited states. To do this, the researchers applied microwave fields at a specific pumping frequency that propagated along a one-dimensional transmission line toward the point-like atom. The photons induced spontaneous emission from the atom, causing it to generate a scattered wave at a specific frequency, amplifying the overall signal. “The key process is the preparation of population inversion (same as in lasers),” coauthor Abdufarrukh Abdumalikov from RIKEN told PhysOrg.com. “Our atom has three discrete energy levels. We apply a microwave which excites it from the ground state to the second excited state. From the latter the atom relaxes partly to ground state and partly to first excited state. When the population of the first excited state is larger than that of the ground state we have a population inversion. Then we apply another microwave signal which we would like to amplify. It should be in resonance with the ground state – first excited state transition. It stimulates this transition and the atom emits a photon which adds up to the signal. The principle is the same as in lasers.”The researchers calculated the maximal gain to be about 1.09, corresponding to an average of 109 emitted photons for every 100 incident photons. Abdumalikov explained that the maximum theoretical gain is 1.125, or 112.5 emitted photons for every 100 incident photons. Overall, the amplification by a single artificial atom provides an example of an elementary quantum amplifier, which could be used as a building block for large-scale, tunable quantum amplifiers for various applications. In addition, the demonstration of single-atom quantum amplification could open up possibilities for developing new types of on-chip quantum amplifiers and other quantum devices, which could reveal novel quantum optical phenomena due to the devices’ strong coupling, tunability and controllability. “This is the first work of this kind,” Abdumalikov said. “If we use many atoms we can obtain larger gain. Such amplifiers can be used in other research fields where low amplifier noise is needed. One such research field is an on-chip version of cavity quantum electrodynamics (QED) that is circuit QED.”
(PhysOrg.com) — Broadcom is highlighting a second coming of Wi-Fi in the name of the new IEEE standard 802.11ac, with this week’s announcement that its products based on the nascent standard will be ready for shipping in the second half of next year. The IEEE 802.11ac is a wireless standard of 802.11 under development. Image: Wikipedia. Wireless network service will be strengthened in three ways: in speed, longer range and battery efficiency. Broadcom provides system-on-a-chip and software solutions. Those who use Broadcom products are computing and networking equipment, digital entertainment, broadband-access, and mobile device manufacturers.At a media event in San Francisco this week, the company executive who talked about Broadcom’s push into 802.11ac also spoke on why the technology was advantageous. Rahul Patel, the company’s vice president of mobile and wireless, said the new version can operate at a speed of as much as 1.3 gigabits per second. The 802.11ac is also being singled out as using the less crowded 5Ghz band, which will be less prone to interference.As for battery advantages, since the speed is faster, it will take less time for the client to work to transmit and receive data compared with the 802.11n client.The new version offers longer range and improved wall penetration , adding up to better home service. Patel said the new speeds will make it ideal “plumbing” for the Internet-connected home. Improved connectedness will come none too soon considering consumer expectations with newer consumer electronic products. Patel said consumers will need faster Wi-Fi soon, to leverage features and functions of home technology devices such as being able to send multiple streams of video to their TVs. More devices than ever are competing for wireless connections in the home. According to a new consumer poll by JZ Analytics, nearly four times as many respondents have six or more wireless devices today than two years ago.The roadmap for the new standard, meanwhile, is populated with decisive stops along the way before full ratification of the standard. The Wi-Fi Alliance is holding its first 802.11ac compatibility testing plug-fest in the second quarter of next year. The event will lead to hardware interoperability. Existing hardware will be able to upgrade for any late changes to the standard via a firmware update This was the same procedure that was followed for 802.11n hardware, say observers.According to an IEEE industry perspective on the topic earlier this year, 802.11ac marks another milestone in wireless LAN throughputs. Since the adoption of the first 802.11 standard in 1997, there has been a steady and exponential growth in the maximum available data rate, said the article, authored by Qualcomm’s Richard Van Nee. The 802.11ac task group began work on the amendment to achieve aggregate throughputs beyond 1 Gb/s in the 5 GHz band. The 802.11ac standard will in turn represent a significant push of wireless LAN throughputs over the gigabit-per-second barrier. © 2011 PhysOrg.com NTT demos 802.11ac – next generation high-speed WiFi Citation: Broadcom will ship 802.11ac products in 2012 (2011, December 10) retrieved 18 August 2019 from https://phys.org/news/2011-12-broadcom-ship-80211ac-products.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. Explore further
(Phys.org)—California based Hound Labs Inc. is claiming to have made a breakthrough in the rush to develop a portable device capable of detecting THC, the active ingredient in marijuana, in the breath of someone that has recently smoked a substance containing the chemical. They claim also that their device will soon be small enough for use by law enforcement to remove impaired drivers from the road. 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. Testing for secondhand marijuana exposure Several states in the U.S. have legalized recreational marijuana use, and even more have allowed it for medicinal use. This trend has law enforcement on edge as there is currently no roadside test that can detect THC use by a driver in real time—instead, if such use is suspected, police officers must take blood or urine samples that can take days to deliver an answer—that makes it difficult to arrest a driver on the spot, which means in some cases, letting them go to continue driving under the influence. Making things even more challenging is that not enough research has been done by scientists to find out how much THC in the body causes impaired driving—states have set different levels, and some have instituted a zero-level tolerance policy.In this new announcement, Hound Labs claims it has developed a device that is capable of detecting minute levels (below 500 picograms) of THC in the breath, which the company also claims is the only way to differentiate between heavy marijuana users who maintain high levels of THC in their bodies even hours or days after use, and those who have recently smoked it, in whatever form. Mike Lynn CEO and co-founder of the company is a practicing emergency medicine physician who has presumably witnessed the tragic consequences of people driving after smoking the drug and is looking to put a stop to it.As part of their announcement, Hound Labs says that it is working with scientists from academic institutions, law enforcement agencies and other researchers and expects to have a product small enough for a police officer to carry and use by the end of next year. They note also that the device will also work as an alcohol breathalyzer and should cost approximately the same as current breathalyzers. Citation: A new portable device to detect marijuana use almost right away (2015, December 3) retrieved 18 August 2019 from https://phys.org/news/2015-12-portable-device-marijuana.html © 2015 Phys.org A dried flower bud of the Cannabis plant. Credit: Public Domain Explore further More information: houndlabs.com/science/
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 Play A user interactively guides a ligand to its binding site in the protein trypsin in virtual reality, adjusting visuals as befits the task. Credit: Helen Deeks, in collaboration with Interactive Scientific Ltd, under CC BY-ND 4.0. © 2018 Phys.org For many years, chemistry students have been taught to manipulate physical models depicting molecules as a means of learning how they work. The researchers note that such models are not up to the task of showing how molecules work dynamically—they cannot show movement or the flexibility of molecules, which leaves students having to imagine how they might look. In more recent years, computer applications that allow students to watch and even manipulate molecules onscreen have led to improvements in teaching techniques. But, as the researchers also note, such apps that generally make use of touch screens still lack the required hands-on approach. To improve on such applications, the researchers have created a VR system that is able to show complex molecules as they exist in a 3-D space. And even better, users are able to physically manipulate the molecules to learn more about their properties.With their new system, the researchers point out, users are able to achieve co-location, which they describe as a phenomenon in which interactions in an actual 3-D physical space align with interactions in a simulated 3-D environment. Their system is cloud-based, which means the data used in the simulations can be constantly updated and improved, even as the system is being used. Play Multiple users performing 3-D molecular tasks in the cloud-enabled virtual reality platform developed in collaboration between the University of Bristol and Interactive Scientific Ltd. Credit: Helen Deeks and Matt Sutton, in collaboration with Interactive Scientific Ltd, under CC BY-ND 4.0. The system currently allows six people to use the system at the same time—they can be in the same room, or other parts of the world. Users use wireless controllers that behave like tweezers, allowing them to grab molecules and their parts.To test their system, the researchers asked 32 volunteers to carry out three different tasks: manipulating a methane molecule through a carbon nanotube, manipulating an organic helicene molecule to change its rotation, and finally, to tie a knot in a polypeptide. They report that most of the volunteers, none of whom had ever used a VR system before, were able to use the system to some degree. Other less rigorous testing showed the system capable of doing things like allowing two people to toss a molecular buckyball back and forth across a real room. The researchers also report that the volunteers reported preferring the VR system over other applications, such as touchscreens. Play A user interactively guides a ligand to its binding site in the protein beta-lactamase in virtual reality. Credit: Helen Deeks, in collaboration with Interactive Scientific Ltd, under CC BY-ND 4.0. 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 A team of researchers affiliated with several institutions across the U.K. has developed a framework for using virtual reality (VR) systems to teach chemistry. In their paper published on the open access site Science Advances, the team describes the system they developed and the advantages it has over standard teaching methods. An abstract representation of the soccer-ball shaped buckminsterfullerene molecules in virtual reality. Credit: Mike O’Connor, in collaboration with Interactive Scientific Ltd, under CC BY-ND 4.0. 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 Less is more when it comes to predicting molecules’ conductivity More information: Michael O’Connor et al. Sampling molecular conformations and dynamics in a multiuser virtual reality framework, Science Advances (2018). DOI: 10.1126/sciadv.aat2731AbstractWe describe a framework for interactive molecular dynamics in a multiuser virtual reality (VR) environment, combining rigorous cloud-mounted atomistic physics simulations with commodity VR hardware, which we have made accessible to readers (see isci.itch.io/nsb-imd). It allows users to visualize and sample, with atomic-level precision, the structures and dynamics of complex molecular structures “on the fly” and to interact with other users in the same virtual environment. A series of controlled studies, in which participants were tasked with a range of molecular manipulation goals (threading methane through a nanotube, changing helical screw sense, and tying a protein knot), quantitatively demonstrate that users within the interactive VR environment can complete sophisticated molecular modeling tasks more quickly than they can using conventional interfaces, especially for molecular pathways and structural transitions whose conformational choreographies are intrinsically three-dimensional. This framework should accelerate progress in nanoscale molecular engineering areas including conformational mapping, drug development, synthetic biology, and catalyst design. More broadly, our findings highlight the potential of VR in scientific domains where three-dimensional dynamics matter, spanning research and education.Anybody wishing to try out the tasks described in the paper can download the software at https://isci.itch.io/nsb-imd, and launch their own cloud-hosted session. Journal information: Science Advances Citation: Using virtual reality systems to teach chemistry in 3-D (2018, July 2) retrieved 18 August 2019 from https://phys.org/news/2018-07-virtual-reality-chemistry-d.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.
Kolkata: New Town’s first Misti Hub is all set to be opened shortly.Final touches are being given and it is likely that the hub will be opened within a month. The hub will given an opportunity to those who come to the city and stay back to buy the famous and mouth-watering sweets of Kolkata. The residents of New Town will get the age-old Kolkata sweets at the hub. The Housing Infrastructure Development Corporation (HIDCO) had imposed a condition that those opening shops must have experience for 25 years or more. Owners of top sweetmeat shops held meetings with senior HIDCO officials including its chairman Debashis Sen and welcomed the idea. Also Read – Heavy rain hits traffic, flightsThere will be 10 branded shops and one ethnic one. So far, seven branded shop owners have agreed to open their outlets. They are: Nabin Chandra Das, Balaram Mullick and Radharaman Mullick, KC Das, Ganguram, Hindusthan Sweets, Bancharam and Gupta Brothers. In the shop selling ethnic sweets the langcha of Shaktigarh, sharbhaja and sharpuria or Krishnanagar, sitabhog and mihidana of East Burdwan and chanabhora of Behrampur, Murshidabad will be available. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe hub is coming up on Biswa Bangla Sarani, off Pancha More near Gate number 3 of Eco Park. Every branded shop will have a glass front showcase freeze and a back room for storage along with a rear entry for supplies. There will be a place where people can sit and enjoy the city’s iconic sweets. Each shop will have its cash counter and packaging. Near the exit, there will be a security check and the packets containing the sweets will be put inside a Misti Hub wrapper to market brand Biswa Bangla. A central atrium with glass walls will bring the sunlight inside. There is a driveway and a free parking lot for a limited period of 30 minutes. The construction of the hub is a combination of tradition with modernity. There will be a caretaker on behalf of HIDCO to look after the facilities. The hub has been built after a shop-in-shop concept.There is a potential market of Bengali sweets both in the country and abroad. The outlets at the Misti Hub are famous and each produce some special sweets. KC Das and Nabin Chandra Das are famous for rasogolla while Bancharam is famous for curd. Balaram Mullick’s mixed sweets have become very famous while Hindusthan Sweets is famous for sandesh.
Kolkata: Police have arrested two contractors, who had assaulted Sheikh Nazimuddin, Vice-Chairman of North Dum Dum Municipality on Wednesday afternoon.The civic authorities have cancelled the licences of the two contractors. Locals staged a demonstration on the road and put up a blockade, demanding immediate arrest of the contractors, who had heckled their beloved leader. Saugata Roy, Trinamool Congress MP went to the spot and brought the situation under control. Nizamuddin said he met the contractors – Tapas and Bapi, who were engaged in laying an underground pipeline in his ward. As there was inordinate delay in completing the work, he asked to expedite the work and complete it. Also Read – Heavy rain hits traffic, flightsThe contractors told him that they would not work and when Nizamuddin was going towards the chamber of a municipal engineer, they attacked him from behind.As the news spread, locals came out on the street and protested against the contractor raj. They demanded stern actions against the two contractors. They put up a road blockade affecting traffic movement. A large contingent of police from Nimta police station arrived at the spot and tried to pacify the residents. The road blocks were later lifted. Saugata Roy said the abuse of one of their party leaders by the miscreants inside the municipality office is most unfortunate. He said a meeting with the chairman of the municipality Kalyan Kar was held and it was decided that the licences of the two contractors will be cancelled.
Nearly 90 per cent of people suffer from damaged knee joints by the age of 60-65 years, orthopedicians have said, adding that in majority of the cases the condition can be prevented by a proper lifestyle and food habits.According to doctors, 80 per cent of the people in urban India suffer from Vitamin D deficiency, which is the sole reason behind decreasing the bone mass density, leading to the increase of osteoporosis.Health organisations estimate that in 2014, a total of 50 million people across India are reported to be either osteoporotic or with low bone mass density. “In our country, joint and back pains are considered as part of the normal aging process. Therefore, instead of dealing with such problem seriously people prefer to go for quick fixes like analgesics or some pain relieving balms. “Such temporary solutions just further worsen the bone and joint conditions,” L. Tomar, a senior orthopedic surgeon at city’s Max super specialty hospital said in a statement on Tuesday. Also Read – ‘Playing Jojo was emotionally exhausting’Though surgery and knee transplants can be a solution for the knee damages, a majority of the people delay their knee surgery till the last stage without knowing that it is actually deteriorating their spine further, doctors opined.He said postponing the right treatment for the knee further worsens the condition and may lead to serious problems in the spine.Rajeev Jain, orthopedic surgeon at Safdarjung hospital said: “To help people avail the benefit of advanced treatment options, it is important that they know about the safer technologies like minimally invasive joint replacement surgeries which offer better clinical outcomes along with ensuring a quicker recovery without much blood loss or a hospital stay.” “…lack of awareness around right eating habits, healthy lifestyle, and available treatment options is further worsening the situation,” said Jain.
Kolkata: Police on Sunday seized banned drugs and arrested three persons, including two students, in this connection during a raid at a city hotel. Acting on a tip-off, police conducted a raid at the hotel and seized 7 gm of MDMA (Methylenedioxymethamphetamine) – an ecstasy drug, 4 LSD blocks and 3 gm of cocaine from the possession of the trio, a senior officer of Kolkata Police said. The students, aged between 18 and 20, and the man (22) had brought the drugs from Delhi with an intention to use them at parties organised at discos in the hotel, and to sell them at a higher price to customers there, he said. “We are questioning them and trying to find out more details… whether they are members of any drug trafficking racket,” the officer added.
Kolkata: The 109th Annual General Meeting of Ramakrishna Mission was held at Belur Math on Sunday where a synopsis of the activities of the Mission was placed.Some new branch centres of Ramakrishna Mission have started operating in Goa, Lumdung, Arunachal Pradesh, Jhargram, West Bengal, New Town, Kolkata, Davanagere, Karnataka and Dibrugarh, Assam. A sub-centre of Lucknow Mission Sevashrama was started at Ayodhya in Uttar Pradesh. The Mission in commemoration the 150th birth anniversary of Swami Abhedananda held four national seminars on Indian Culture and Philosophy and a number of other programmes were held at different centres of Ramakrishna Math and Ramakrishna Mission. The 150th birth anniversary of Sister Nivedita was celebrated by the headquarters and a number of branch centres in India and abroad. A few new books on Sister Nivedita were also published in different languages.