Days after releasing a separate manifesto, a Sankalp Patr, for the municipal polls, a first for any party in the state, Chief Minister Yogi Adityanath on Tuesday kicked-off his poll campaign. His first stop was politically and symbolically significant, Ayodhya, which was elevated to the status of a municipal corporation after the BJP came to power in March.The Bharatiya Janata Party is going all out to campaign for the urban body polls in Uttar Pradesh in a bid to replicate the thumping win it registered in the Assembly elections eight months ago.Mr. Adityanath is expected to address more than three dozen rallies for the municipal polls, in a style similar to Prime Minister Narendra Modi’s campaign strategy.Addressing a rally in Ayodhya, Mr. Adityanath accused the previous Samajwadi Party government of neglecting it and of trying to restrict and tarnish the “pehchaan” (identity) and grandeur of the town in the eyes of the world. Those who “discriminated with your identity”, can never be forgiven, he told voters in Ayodhya.Mocking the Samajwadi Party and the Bahujan Samaj Party, Mr. Adityanath said the two parties were struck by “electric current” each time he visited Ayodhya.“Ayodhya is a symbol of faith for us. Ayodhya is the land of maryada purshottam Shri Ram…Ayodhya should get back its glory,” the Chief Minister said. Traditionally strong in urban areas, the BJP secured 10 of the 12 mayor posts in 2012.This time mayoral elections will be held for 16 posts, with the inclusion of four new seats including Mathura (Vrindavan) and Ayodhya, names emphasized by Mr. Adityanath in his speech.While mentioning that his government had already inaugurated development projects worth ₹ 137 crore in Ayodhya, Mr. Adityanath promised more schemes after the polls. He claimed credit for restoring grand Diwali celebrations in Ayodhya and said that his government’s priority was to make the town “shine” and bring a smile to the face of every person who visited it. “Ayodhya gave Diwali to the world but Diwali disappeared from Ayodhya. We restored it,” he said.While appealing for votes for the BJP candidates, Mr. Adityanath followed up on the promise made by his party in the manifesto and said that a gaushala would be built in all major cities cater to stray cattle.After Ayodhya, Mr. Adityanath is expected to hold campaign rallies in all major centres of UP, including Kanpur, Varanasi, Allahabad, Muzaffarnagar, Gorakhpur, Jhansi, Lucknow and Mathura, with more than two rallies per day on average.Polls would be held for over 650 posts, including 16 Mayors and 200 Nagar Palika Parishads, starting November 22 in three phases. Results will be declared on December 1.
Tis the season of flagship and flagship killer smartphones. While the budget and lower mid-range segment has remained largely consistent — and somewhat saturated — with what’s in store, it was the upper mid-range and premium segment of the smartphone market that saw a lot of activity in June. As such, options within the upper mid-range and premium segment of the smartphone market, have now grown by leaps and bounds. And as always, the more the merrier.Cheapest phone(s) we recommendXiaomi Redmi 4Xiaomi VP and India MD Manu Kumar Jain only recently announced that the company had sold over 10 lakh units of the Redmi 4 phone in the country in 1 month since launch. The Redmi 4, in fact, beat the Redmi Note 4, that achieved the same sales figure in 45 days, Manu added. The Redmi 4 was launched in India in mid-May at a starting price of Rs 6,999 for the 2GB RAM and 16GB storage version going all the way to Rs 10,999 for the top end 4GB RAM and 64GB storage version. The Redmi 4 is also available in 3GB RAM and 32GB memory version for Rs 8,999.Much like the Redmi 3S (and Redmi 3S Prime) before it, the Redmi 4 also brings in some hard-to-get hardware specs at some really rock-bottom prices. Sales figures aside, the Redmi 4, is quite the bang for your buck no matter which version you chose to buy, justifying its growing popularity. The 2GB RAM and 16GB storage version that sells for Rs 6,999 is the most affordable ‘smart’ phone that you can buy and rest assured, it won’t disappoint you.It looks really good, feels really good, has a neat display, dependable performance, good-enough cameras and killer battery life. Boasting of a full-metal body — with a rear-mounted fingerprint scanner — the Xiaomi Redmi 4 comes with a 5-inch 720p display and an octa-core Qualcomm Snapdragon 435 processor under the hood. It sports a 13-megapixel rear camera with PDAF and a 5-megapixel front-facing camera. On the software side, the Redmi 4 comes with Android 6.0 Marshmallow-based MIUI. Furthermore, the phone is backed by a 4,100mAh battery.advertisementXiaomi Redmi 4AAlternatively, if you’re someone who is on an even more tighter budget, Xiaomi’s ultra-affordable Redmi 4A , that sells for Rs 5,999, is also well worth a try. The Redmi 4A looks a lot like the Redmi 3S, but unlike the Redmi 3S, the Redmi 4A has a polycarbonate shell. In terms of hardware specs, the phone comes with a 5-inch HD IPS display with a 720p resolution. It is powered by a 1.4GHz quad-core Qualcomm Snapdragon 425 processor coupled with Adreno 308 GPU, 2GB RAM and 16GB of internal storage which is further expandable via micro-SD card slot. The dual-SIM phone runs Android 6.0.1 Marshmallow-based MIUI 8 out-of-the-box and supports 4G LTE (VoLTE-ready) connectivity.On the camera front the Redmi 4A comes with a 13-megapixel camera on the rear with f/2.2 aperture along with autofocus and an LED flash. On the front you get a 5-megapixel snapper. The phone is backed by a 3,120mAh battery which is non-removable.Best phone under Rs 10,000Xiaomi Redmi Note 4Although launched in January, Xiaomi’s Redmi Note 4 still holds its ground in the under Rs 10,000 price segment. Backed by a premium design, top-notch performance and fantastic battery life, the Redmi Note 4 still remains to be the smartphone to beat at its price point. Follow up to Xiaomi’s much successful Redmi Note 3; the Redmi Not 4 exists primarily to correct the camera shortcomings of its predecessor, according to the company. The phone comes with a 13-megapixel camera on the rear with f/2.0 aperture, Phase Detection Autofocus and dual-LED (dual-tone) flash. On the front, the Redmi Note 4 comes with a 5-megapixel camera.Just like the Redmi Note 3, the Redmi Note 4 boasts of a full-metal body and a rear-mounted fingerprint scanner. Unlike the Redmi Note 3, however, the Redmi Note 4 has curved 2.5D glass on the front (with physical capacitive keys) and a bottom-facing mono speaker.The phone comes with a 5.5-inch 1080p IPS LCD display. It is powered by a Qualcomm Snapdragon 625 processor clubbed with Adreno 506GPU. The base 2GB RAM and 32GB storage version of the Redmi Note 4 sells for Rs 9,999 and support expandable storage of up to 128GB via a hybrid micro-SD card slot as well. The dual-SIM phone runs Android Marshmallow-based MIUI 8 and supports 4G LTE (VoLTE-ready). The Redmi Note 4 is further backed by a 4,100mAh battery.Best phone(s) under Rs 20,000Moto G5 PlusLast year’s Moto G4 and Moto G4 Plus weren’t as revolutionary as the original Moto G. Even though the Moto G4 and Moto G4 Plus stuck with the original’s philosophy — of cramming in some noteworthy specs at dirt cheap prices — somewhere down the line, competition was really starting to catch up. The Moto G4 and Moto G4 Plus were good. They were just not good enough. This year’s editions, the Moto G5 and Moto G5 Plus, are different. Just like last year’s Moto Gs, the Moto G5 and Moto G5 Plus, differ in key hardware specs. While the Moto G5 is a good enough phone, the Moto G5 Plus is in fact the phone to buy if you have a budget of under Rs 20,000.advertisementAlso Read: Moto G5 Plus review: Pure Android, good camera make it best phone under Rs 20,000The Moto G5 Plus starts at Rs 14,999 for the base 3GB RAM and 16GB storage version and goes all the way to Rs 16,999 for the top-end 4GB RAM and 32GB storage version.The Moto G5 Plus is an all-metal phone with Corning Gorilla Glass 3 and splash-resistance coating. It comes with a 5.2-inch 1080p screen and is powered by Qualcomm’s heat efficient Snapdragon 625 processor. The Moto G5 Plus, like other Moto phones, runs an almost unmodified version of Android Nougat with Moto enhancements like Moto Display and Moto Actions alongside the Google’s AI assistant.The Moto G5 Plus sports a 12-megapixel camera on the rear with dual pixel autofocus, f/1.7 aperture and dual-LED flash. It’s a significant upgrade over the camera on-board the Moto G4 Plus. Additionally, the Moto G5 Plus’ rear camera is also capable of recording 4K video. On the front, it comes with a 5-megapixel camera.The Moto G5 Plus is backed by a 3,000mAh battery and supports fast charging.Huawei Honor 8The Honor 8 was launched in India in October last year at a price of Rs 29,999. If you’re wondering why the Honor 8 even deserves a mention here, 8 months after hitting the shelves, well, the phone from Huawei is now selling for as low as Rs 17,350. It is actually quite a steal at its current price if you’re someone who likes to flaunt their phone and also someone who likes to take a lot of (good) pictures using it.The Honor 8 has two cameras on the rear — dual 12-megapixel with dualLED (dual tone) flash — wherein one takes monochrome shots the other takes photos in colour (RGB). The phone’s software algorithm then merges both the images into one and creates the final photo. The monochrome images can take in 300 per cent more light and 50 per cent more contrast than coloured photos, according to Huawei. So basically, the phone can ideally take better low-light photos than rival top-tier phones thanks to its dual-lens system. The Honor 8, in addition, also has an 8-megapixel camera on the front.The Honor 8 further boasts of an all glass and metal body with rear mounted fingerprint scanner. It comes with a 5.2-inch 1080p display and an octa-core HiSilicon Kirin 950 processor clubbed with 4GB RAM under the hood and 32GB of on-board storage which is further expandable by up to 128GB via micro-SD card. The phone is backed by a 3,000 mAh battery.advertisementBest phone(s) under Rs 30,000Moto Z2 PlayJust like the Moto Z Play, the Moto Z2 Play brings the Moto Z family’s modularity to the affordable mid-range segment. But being an affordable mid-range modular phone — and a modular phone done right — isn’t the only USP of the Moto Z2 Play, for its loyalties lie elsewhere. The Moto Z2 Play, just like the Moto Z Play before it, has a battery life to die for.The Moto Z2 Play, priced at Rs 27,9999, uses a Qualcomm Snapdragon 626 processor and comes with 4GB RAM and 64GB storage. The phone comes with a 5.5-inch Super AMOLED display with a Full-HD (1080P) resolution. One particular interesting bit about the Moto Z2 Play — as opposed to its predecessor — is its main camera. This camera uses a 12-megapixel image sensor that has a pixel size of 1.4um. Just like its predecessor the Moto Z Play, the Moto Z2 Play also comes with a decently-sized 3,000mAh battery and when paired with Qualcomm’s efficient Snapdragon 626, metes out excellent battery life.The Z2 Plus further comes with a full-metal body and has a fingerprint sensor on the front and on the back the phone has pogo pins through which Moto Mods can be attached to it. It also comes with Type C connector. Also the support for micro-SD card has been provided.Also Read: Moto Z2 Play review: Great battery life, pure Android makes it one of the best Moto phonesLike other Motorola phones, the Z2 Play also uses an almost unmodified version of Android. It is powered by Android Nougat 7.1, which is the latest version of Android.OnePlus 3TThe OnePlus 3T — even though OnePlus has discontinued the phone now (it will be available for buying in India by the end of this year though) — is one of those rare case studies where it’s hard to find a catch, simply because there isn’t any. The 6GB RAM and 64GB storage version of the OnePlus 3T is available for buying for Rs 29,999 and is still among the best phones that money can buy around its price point chiefly because of its blazing fast performance.Just like the original OnePlus 3, the OnePlus 3T boasts of a full-metal body and a front-mounted fingerprint scanner. The phone has a 5.5-inch full-HD AMOLED display with a 1920×1080 pixels resolution. The phone comes with curved 2.5D Corning Gorilla glass 4. The phone is powered by a 2.35GHz quad-core Qualcomm Snapdragon 821 processor coupled with Adreno 530 GPU. It is backed by a 3,400mAh battery. It comes with 6GB RAM and supports 4G LTE and NFC connectivity options.Also Read: OnePlus 3T review: Best phone in India right nowThe phone runs Android 6.0.1 Marshmallow-based OxygenOS out-of-the-box and is up-gradable to Android N.The OnePlus 3T also supports the company’s in-house fast charging solution called Dash Charging and the accompanying Dash Charger is capable of charging the phone to up to 60 per cent in just 30 minutes.The rear camera (which is the same as the one on-board the OnePlus 3, which means 16-megapixel camera (Sony IMX 298) with PDAF, f/2.0 aperture and Optical Image Stabilisation as the one on the OnePlus 3) is assisted with EIS for enhanced stabilisation while shooting videos. On the front, the OnePlus 3T comes with a 16-megapixel camera.Best phone(s) under Rs 45,000OnePlus 5The OnePlus 5 is officially official now. It looks a lot like, well, a certain phone from a certain company that shares its name with a fruit that apparently keeps doctors away. But, we had all – already — seen how the OnePlus 5 was shaping to be, didn’t we? So, what if the OnePlus 5 looks a lot like a certain phone from a certain company that shares its name with a fruit that apparently keeps doctors away? At least, it looks good, while at it. It is, without a doubt, OnePlus’ best-looking phone ever. It’s still pretty jam-packed to the core with high-end specs, like the company’s previous offerings, and also it comes at a relatively mainstream price which come to think of it is again trademark OnePlus.Also Read: OnePlus 5 review: Crazy good phone for crazy good priceThe OnePlus 5 looks exactly like the OnePlus 3T from the front, only a wee bit more compact. The only difference — on the front — is that OnePlus’ new phone comes with Corning’s new Gorilla Glass 5 for protection and what is being said to be a more durable fingerprint scanner. The rear, in the case of the OnePlus 5, is a different story altogether. The OnePlus 5, as opposed to the OnePlus 3T, comes with a dual camera system on the rear.The dual camera system in the OnePlus 5 features “a tailor-made 16-megapixel camera, supported by a 20-megapixel telephoto camera. While the 16-megapixel camera — Sony IMX 398 — features a large f/1.7 aperture, the secondary 20-megapixel camera — Sony IMX 350 – features an f/2.6 aperture. The dual camera system on-board the OnePlus 5 is capable of shooting photos with shallow depth of field, or bokeh effect through a specialized portrait mode. There’s also a dedicated Pro Mode for pro users. The system is also capable of recording 4K videos and shooting in RAW file format. Sadly, the OnePlus 5’s rear camera system isn’t assisted with Optical Image Stabilisation. On the front, the OnePlus 5 comes with a 16-megapixel camera.The OnePlus 5’s dual camera system may be a hit or a miss — it is in fact not as good as hyped by the company in question — but it doesn’t take away the fact that the OnePlus 5 is the most powerful phone that you can buy at its price point right now. The phone is powered by a 2.45GHz octa-core Qualcomm Snapdragon 835 processor clubbed with up to 8 gigs of RAM and up to 128GB of internal storage which is non-expandable. It runs Android 7.1.1 Nougat-based OxygenOS out-of-the-box.The phone is further backed by a 3,300mAh battery which is non-removable and supports Dash Charging.The only area where OnePlus seems to have cut corners is in the display, as the OnePlus 5 comes with the exact 5.5-inch 1080p AMOLED screen as the OnePlus 3 and 3T before it.The OnePlus 5 starts at Rs 32,999 for the base 6GB RAM and 64GB storage version and goes all the way to Rs 37,999 for the top-end 8GB RAM and 128GB storage version.LG G6The G6 is LG’s best phone ever. In fact, it’s safe to say, that it’s among the best flagship Android phones in the market right now. It may not look as good as Samsung’s Galaxy S8, but, that’s not really what LG’s phone is going after. For the first time in a very long time, LG is chasing practicality. With the G6 it has achieved most of it. Without compromising on gimmicks.Launched at Rs 51,990 the LG G6 is now selling for as low as Rs 38,199 which makes its quite a steal because, well, it is after all a fantastic phone. Successor to the G5, the LG G6 comes with an unusual 18:9 Full Vision display — instead of a regular 16:9 — and a wide-angle 13-megapixel dual rear camera system. The LG G6 is also notably the world’s first smartphone to support Dolby Vision (and HDR 10) for enhanced videos, a feature which was until now limited to high-end TVs.Also Read: LG G6 review: The dark horseThe USP of the G6, according to LG, is its ‘big screen that fits.’ The phone comes with ridiculously slim bezels allowing the display to take up over 80 per cent of its front side. The 5.7-inch QHD+ 18:9 Full Vision display of the G6 boasts of a 2,880×1,400 pixel resolution which when combined with LG’s Android Nougat-based UX 6.0 software allows users to run apps in two perfectly square windows side by side.On the inside, the phone is powered by a 2.35GHz quad-core Qualcomm Snapdragon 821 processor clubbed with Adreno 530 GPU and 4GB of RAM. It comes with 64GB of internal memory which is further expandable via a micro-SD card slot. It is further backed by a 3,300mAh battery with support for fast charging. The G6 India model, in addition, includes a Hi-Fi quad DAC for enhanced audio.On the outside, the LG G6 comes with a ‘minimalist’ design consisting of Corning Gorilla Glass 5 (Gorilla Glass 3 on the front) and metal — with chamfered edges and rounded corners — and a rear-mounted fingerprint scanner. The LG G6 is also IP68-certified for dust and water resistance.Best phone(s) money can buySamsung Galaxy S8/Galaxy S8+The Galaxy S8/Galaxy S8+ from Samsung are a heady concoction of style and cutting-edge technology. There’s so much to love about the Galaxy S8 and Galaxy S8+, it’ll make you want to forget everything about the infamous Galaxy Note 7. The fact that they’ve got everything — straight out of the future looks and straight out of the future tech — makes them a complete package: a true value for money proposition even at a price as high as Rs 57,900 and Rs 64,900.The Galaxy S8+ is simply the Galaxy S8 with a bigger (6.2-inch) screen and a bigger (3,500mAh) battery. The Galaxy S8 will serve most users well. For others, there is the Galaxy S8+.The Galaxy S8 and S8+, which are successors to last year’s Galaxy S7 and S7 Edge, come with a near edge-to-edge design, an unusual 18.5:9 ‘Infinity’ display and Samsung’s proprietary Bixby virtual assistant. While the Galaxy S8 is a 5.8-inch phone, the S8+ has a 6.2-inch screen. Both the phones boast of a 2960×1440 pixel (WQHD+) resolution and Super AMOLED panels.Both the phones are powered by a 2.3GHz octa-core Exynos 8895 processor clubbed with Mali-G71 MP20 GPU and 4 gigs of RAM along with 64GB of internal memory. The dual-SIM phones run Android Nougat-based TouchWiz UI — Samsung Experience UX — and support 4G LTE connectivity.Also Read: Samsung Galaxy S8, Galaxy S8+ review: Cutting the edge and doing it in styleBoth the Galaxy S8 and Galaxy S8+ come with a rear-mounted fingerprint scanner, an iris scanner and facial recognition for biometric security. Both the phones come with Samsung Pass to store all your passwords in one place. Samsung Pay is also supported out-of-the-box. The Galaxy S8 and S8+ also come with a Windows Continuum-like feature called Samsung DeX that allows you to run supportive mobile apps on a full-scale monitor for enhanced productivity.On the camera front, both the phones come with a 12-megapixel ‘dual-pixel’ rear (with f/1.7 aperture and optical image stabilisation) and an 8-megapixel front shooter combo.While the Galaxy S8 uses a 3,000mAh battery, the Galaxy S8+ houses a bigger 3,500mAh battery. Both the phones support wireless and quick charging technologies (via USB Type-C port). The phones are also IP68-certified for water and dust resistance.HTC U11Even though it doesn’t have an edge-to-edge screen like the Samsung Galaxy S8, or a dual-camera system like the LG G6, HTC’s new U11, has enough gimmicks and fire-power under the hood to stand toe-to-toe with them. And give them quite a run for their money while at it. It looks great, has a great screen, metes out great performance, comes with great camera credentials and a camera that performs quite well while at it, and outstanding audio credentials that put Apple’s iPhone 7 Plus’ stereo setup to shame. It is water-resistant and crams in three virtual assistants. But, more importantly, the U11 is the first HTC phone in years to carry a sensible price tag. The phone, for 6GB RAM and 128GB storage, costs Rs 51,990.The outer frame, in case of the U11, can respond to stimuli. The lower ends of the phone pack sensors that respond differently to different levels of pressure, giving the U11 its ‘squeezable’ moniker. By squeezing the phone, users can carry out specific functions such as opening the camera (and clicking photos), activating a virtual assistant, taking a screen-shot and more.The U11 also comes with HTC’s new sonar-based audio system — called U-Sonic — over headphones that is claimed to deliver true sound that is also capable of adapting to the user. The U11 comes without a regular 3.5mm audio jack and has a single USB Type-C out for charging, data syncing and high-res audio. HTC U Sonic, however, works only with compatible USB-C headphones. The company ships one in the box. The headphones, besides supporting U-Sonic, also support active noise cancellation. The phone also ships with a USB Type-C to 3.5mm dongle in the box to connect regular headphones. The U11, in addition, also supports BoomSound Hi-Fi sound technology over a pair of stereo speakers.Also Read: HTC U11 review: Sense and sensibilityThe HTC U11 comes with a 5.5-inch 2K Super LCD 5 screen. It is powered by a 2.45GHz octa-core Qualcomm Snapdragon 835 processor clubbed with up to 6GB RAM and up to 128GB of internal memory which is further expandable via a hybrid micro-SD card slot. The dual-SIM phone runs Android 7.1.1 Nougat-based Sense UI. It further comes with a 16-megapixel front-facing camera and is backed by a 3,000mAh battery and supports Quick Charge 3.0.The U11 ships with a 12-megapixel rear camera with what HTC calls UltraPixel 3 technology and UltraSpeed Autofocus. It uses a very bright lens at f/1.7 aperture, and the sensor is also a little bigger than the usual, 1/2.55-inch that apparently boosts low-light performance. HTC’s UltraPixel sensor is notorious for allowing more light into the lens, technically resulting in brighter photos. The rear camera is further assisted with phase detection autofocus, OIS and dual-LED (dual tone) flash. On the front, it comes with a 16-megapixel camera.
A Dhaka court on Sunday sent opposition Bangladesh Nationalist Party (BNP) leader Joynal Abdin Farroque to jail when he surrendered before it in four arson cases filed with Paltan police station in 2015, reports UNB.Metropolitan magistrate Nurunnahar Yasmeen rejected the bail petitions filed by the BNP leader.However, the court granted him bail in two other arson cases.All the cases were filed with the Paltan police station against Farroque during the countrywide blockade enforced by the BNP-led 20-party alliance in 2015.
(Phys.org) — Since the first demonstration of microelectromechanical systems (MEMS) in the mid-‘80s, the technology has not proven as useful as originally anticipated. One of the problems is that the tiny components tend to stick together due to strong surface adhesion forces on the nanoscale, an effect that engineers call “stiction.” Now in a new study, scientists suggest that this problem might be solved by inducing quantum levitation between components, which they demonstrate by simply adding a thin metallic coating to one of the interacting surfaces. Journal information: Applied Physics Letters Explore further Researchers see exotic force for first time More information: Mathias Boström, et al. “Ultrathin metallic coatings can induce quantum levitation between nanosurfaces.” Applied Physics Letters 100, 253104 (2012). DOI: 10.1063/1.4729822 By preventing stiction, quantum levitation may offer a way to prevent surfaces used in MEMS and nanoelectromechanical systems (NEMS) from crashing together due to other attractive van der Waals forces that exist between them. Since the thickness of the nanocoating changes the dielectric properties of the interacting surfaces, researchers would have to precisely determine the correct thickness for a desired levitation distance. If the technique works, it may provide a much needed revitalization of the fields of MEMS and NEMS.In the future, the researchers plan to extend their investigations to other materials, such as zinc oxide and hafnia, which are widely used in microelectrical and microoptical devices. They also have an upcoming paper (arxiv.org/abs/1206.4852v1) in which they investigate the repulsive and attractive forces between excited Cesium atoms that are confined in a nanochannel, which are very different from those in free space.“Two Cesium atoms that are close together and in an excited state can form unusually large molecules when they are between two gold surfaces,” explained coauthor Mathias Bostrom of the Norwegian University of Science and Technology in Trondheim, Norway, and Australian National University in Canberra, Australia. “The effects from retardation for these excited state interactions between atoms are very similar to what we found for the Casimir-Lifshitz force between a gold-coated silica surface and a silica surface in toluene. Hence we found long-range attraction that brings the atoms together and short-range repulsion enabling bound states (preventing the atoms from crashing together, i.e., forming super large molecules).”Finally, the researchers plan to further investigate how quantum levitation may be used for NEMS systems by looking at anisotropic effects, which are the different properties that arise when parallel or perpendicular to the material interface.“Our colleagues in Oslo (Professor Clas Persson of the University of Oslo and his team) have calculated the actual optical properties of the materials (the dielectric function) for thin gold sheets which will be used to investigate how anisotropic effects may influence NEMS systems with gold nanocoatings. It is likely that the range with repulsive forces (preventing the system from crashing together) may be influenced in such improved calculations. Our aim is to do such calculations this autumn.” Two pieces of silica – one with a gold nanocoating – will experience a repulsive Casimir-Lifshitz interaction beyond a critical distance. Without the gold nanocoating, the interaction would be attractive at the same distance. Image credit: Boström, et al. ©2012 American Institute of Physics The team of researchers, from institutions in Norway, Australia, and Sweden, has published the study on quantum levitation between nanosurfaces in a recent issue of Applied Physics Letters.The odd thing about this levitation is that it stems from the Casimir-Lifshitz force, which has the unusual property of being either attractive or repulsive. As a type of van der Waals force, it arises between nearby particles due to their inherent electrical properties. In this study, the scientists looked at the Casimir-Lifshitz force that occurs between two silica surfaces in a liquid (either bromobenzene or toluene). Normally, this force is attractive, but it weakens as the silica particles move further apart. This weakening is called retardation, and the researchers found that they could decrease the distance at which retardation occurs by coating an ultrathin layer of gold on one of the silica surfaces. This small modification shifts the retardation regime from a separation distance of several nanometers down to a few nanometers by modifying the dielectric properties of the coated silica surface. In fact, retardation weakens the attraction so much that the force becomes repulsive when the surfaces are separated by a few nanometers or more, at a critical distance called the levitation distance. Below the levitation distance, the force again becomes attractive, while above this distance it becomes increasingly repulsive up to a maximum point. At still larger distances, the repulsion stabilizes below the maximum value. The ability to control the Casimir-Lifshitz force is not completely new. Scientists have known about these effects theoretically since the 1970s, but only recent advances in nanotechnology have allowed for experimental investigations. “The interaction between two silica objects in toluene is attractive,” coauthor Bo Sernelius of Linköping University in Sweden told Phys.org. “Previous studies have shown that, if one of the objects is replaced by a solid gold object, the interaction turns repulsive for distances beyond the levitation distance. Thus there is a potential barrier that reduces the chance for the objects to come close and stick to each other. We found, and this is new, that if instead of having a solid gold object we had a silica object with a thin gold coating, the levitation distance shrunk and the barrier became higher. The chance of preventing stiction increased considerably.” Copyright 2012 Phys.org 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. Citation: Quantum levitation could prevent nano systems from crashing together (2012, July 2) retrieved 18 August 2019 from https://phys.org/news/2012-07-quantum-levitation-nano.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.