Broadband invisibility in the microwave range

first_img Explore further Citation: Broadband invisibility in the microwave range (2009, September 11) retrieved 18 August 2019 from ( — In the series Star Trek, Klingons and Romulans have spaceships outfitted with cloaking devices that hide their presence from sight, as well as from the sensors of their rivals’ spaceships. Unlike current invisibility cloaks, which are mostly effective only over a narrow range, these fictional devices provide a broadband type of invisibility that so far has eluded modern scientists. New invisibility cloak allows object to ‘see’ out through the cloakcenter_img Now, though, a team at the Helsinki University of Technology in Finland has demonstrated broadband cloaking of cylindrical objects in the microwave regime. “This really is a helpful development,” Sergei Tretyakov tells “Most other invisibility devices are very narrow in the range they affect.” Additionally, many invisibility cloaks are produced with the use of materials with extreme electromagnetic properties. “These are exotic materials that often have a great deal of loss and are dispersive,” Tretyakov continues.Along with Pekka Alitalo, Olli Luukkonen and Constantin Simovski, Tretyakov believes that invisibility can be obtained over a broader range of frequencies without the need for electromagnetic mumbo-jumbo. Instead, the Helsinki team makes use of a simple metallic structure made from layers. The results of their experiment can be seen in Physical Review Letters: “Broadband electromagnetic cloaking of long cylindrical objects.”“Even though we are cloaking an object from electromagnetic waves, we don’t need to use special materials with exotic electromagnetic properties to create a cloak,” Tretyakov says. “Instead, it is possible to cloak objects shaped like cylinders using simple structures made from conducting layers.” These cloaking devices are also invisible. The experiment blocking microwave frequencies was done using a waveguide. The cylinder was enclosed with conducting sheets orthogonal to the electric field vector. Tretyakov points out that this setup is ideal for antennas, since it can help weed out interference. “Radio astronomy can probably benefit greatly from this, as you can create support for an antenna, and block out interference. In fact, the cloaking device itself could be an antenna.” One of the advantages of this cloaking device is that it can conduct an electrical current, and offers low loss. Additionally, the fact that it is made from normal metal means that the setup tested in Helsinki would be simpler and less expensive to make than some of the electromagnetic cloaking devices currently being tested.For the most part, this experiment shows a type of broadband invisibility that could be achieved in communications and frequencies dealing mainly with radio. However, Tretyakov and his colleagues also performed a simulation of their cloaking setup in the optical range. “We couldn’t so far make an experiment in the optical range,” he admits, “but our setup should be scalable. And our simulation shows that this should be possible to do with visible objects, not just hiding them in the microwave range.”“Right now we are looking for a little help to set up optical experiments,” Tretykov says. “We want to make the experiment, and it should be possible. But it is a little more complex than using the microwaves, and requires a little more time and funding to set up. But technologically, we should be able to do it.”Perhaps that advanced broadband cloaking device is a little closer than we thought.More Information: Tretyakov, et. al. “Broadband electromagnetic cloaking of long cylindrical objects,” Physical Review Letters (2009). Available online: Copyright 2009 All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

Panasonic hands control of home appliances to Android phones

first_img © 2012 Phys.Org More information: … 21-9/en120821-9.html Citation: Panasonic hands control of home appliances to Android phones (2012, August 23) retrieved 18 August 2019 from Home appliances get ‘smart’ at CES Panasonic plans to release first the refrigerator app next month and the other five appliances in October or later. Panasonic has no details on when the appliances with their apps will be available elsewhere than just Japan.The point of the launch is to enable Android users to remotely turn on or control any compatible home appliance. The six home appliances are air conditioner, refrigerator, washing/drying machine, body composition meter, activity meter and blood-pressure meter.Do consumers really want to go to lengths of checking and measuring exactitude in cooking, washing, and storing foods? Or will they see this as an added layer of complexity they can do without? Signs are that Panasonic is tapping further into the market base of people eager for smarter control and customization of home tasks for clean-energy and power-saving cost cuts. In June, Panasonic started its cloud services for a microwave oven and steam rice cooker. Owners take their Android smartphones to look for recipes and program cooking instructions.-In the new lineup, the benefits are promoted as being able to monitor energy savings and possibly cut energy costs. The washing machine app lets the user set the washing cycle with the smartphone. When the phone touches the machine, appropriate amounts of the detergent and softener calculated from the amount of laundry are displayed on the screen of the machine. When the user drops detergent in the machine, amounts are displayed on the screen.Refrigerator data displayed on a smartphone can check for power consumption efficiency. Collected data is sent to the server. Air conditioner users can control their air conditioners remotely from outside the home. The new service will also allow owners of Panasonic healthcare products to create graphs tracking their weight and calories consumed by everyday activities. The point is to make it easy to manage healthcare data. “Panasonic’s smart solutions are designed to make the user’s everyday life more comfortable, convenient and energy efficient,” said the company announcement released earlier this week.The appliances affected include Panasonic’s X Series room air conditioners, a top-mount refrigerator, drum-type washer-dryer ,body composition monitor, calorie meter and blood pressure monitor.The new air conditioners will also work with Apple’s iPhones as well as Android phones.center_img Explore further (—In a cloud-service announcement this week, Panasonic is placing the smartphone into the center of devices for cooking and washing in the home, to be used in conjunction with Panasonic compatible home appliances. The consumer electronics company has launched its own Panasonic Smart App to go to work in Japan. To use the software, it is necessary to become a member of the “Club Panasonic.” The Panasonic Smart App will allow Android smartphone owners hooking up the club to control their smart home appliances just by downloading the free app to their smartphones. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

Research trio crack RSA encryption keys by listening to computer noise

first_img 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. ( —A trio of researchers in Israel has discovered that it is possible to crack 4096-bit RSA encryption keys using a microphone to listen to high-pitch noises generated by internal computer components. Adi Shamir (co-inventor of RSA), Daniel Genkin and Eran Tromer have published a research paper describing the technique on a Tel Aviv University server. More information: RSA Key Extraction via Low-Bandwidth Acoustic Cryptanalysis: Computers make noises, the researchers explain, far beyond the whirring of the fan. The CPU, for example, emits a high pitched noise as it operates, fluctuating depending on which operations it is performing—other components do likewise. Suspecting that they might be able to exploit this characteristic of computers, the researchers set about creating software to interpret noise data obtained using simple microphones and very little other equipment. They also focused exclusively on trying to achieve one single feat: deciphering an RSA encryption key. After much trial and effort, the researchers found it could be done without much effort.Listening and detecting the noise made by a computer as it processes a single character in an encryption key would be impossible, of course, so the researchers devised a method that causes the noise to be repeated enough times in a row to enable capture of its signal. And that can only happen if the attacker is able to send a cyphertext to the machine that is to be attacked and have it processed. The cyphertext contains code that causes looping. By listening to how the computer processes the cyphertext, the researchers can map the noises made by the computer as it crunches different characters, thereby allowing encryption keys sent by others to be cracked.What’s perhaps most frightening about this method is how easily it can be ported to various machines. The researchers found, for example, that by using a laptop and simple hardware and software they were able to crack encryption keys on a second laptop. Next, they did the same thing using a cell phone as the listening device. They suggest it could also be packaged completely in software and sent out as malware, hacking encryption keys on infected devices and sending them back to the hacker.As a side-note, the researchers also found that low-bandwidth attacks on computers are also possible by measuring the electrical potential of a computer’s chassis while the circuitry is busy doing its work. Researchers at Toshiba design quantum network for secure communications Explore further © 2013 Physical setup of a key recovery attack. A mobile phone (Samsung Note II) is placed 30 cm from a target laptop. The phone’s internal microphone points towards the laptop’s fan vents. Full key extraction is possible in this configuration and distance. Credit: Daniel Genkin et al. Citation: Research trio crack RSA encryption keys by listening to computer noise (2013, December 19) retrieved 18 August 2019 from read more

Improving electron transfer in enzymatic biofuel cells

first_img Citation: Improving electron transfer in enzymatic biofuel cells (2018, June 12) retrieved 18 August 2019 from A team of researchers with members from institutions in Singapore, China and the U.K. has found a way to improve electron transfer in enzymatic biofuel cells. In their paper published in the journal Nature Energy, they describe their technique and how well it works. Huajie Yin and Zhiyong Tang with Griffith University in Australia and the National Center for Nanoscience and Technology in China, offer a News & Views piece on the work done by the team in the same journal issue. Journal information: Nature Energy Explore further Enzymatic biofuel cells are, as their name implies, a type of fuel cell based on enzymes as catalysts instead of expensive metals. Because of their potential, scientists have been eager to find ways to overcome problems that have inhibited commercial applications—they are expected to be much cheaper to make than those now in use. Currently, enzymatic biofuel cells are inefficient, have a short lifespan and do not produce much power. These problems, the researchers note, are due to the difficulty in wiring enzymes and electrode surfaces. In this effort, they claim to have overcome some of that difficulty by combining two previously developed methods aimed at solving the problem. The first method involves connecting an enzyme to the surface of an electrode in such a way as to allow the electrons to tunnel between the two—it is called direct electron transfer. The second method involves a mediator that is used help the transfer—it is called, quite naturally, mediated electron transfer.The researchers combined the two approaches to take advantage of the benefits of each. They used laccase as the enzyme and designed a transfer system that connected to a special type of carbon nanotube surface to further improve electron transfer. The system was made of three parts, an ABTS compound (to serve as a mediator), situated between a polypyrrole group at one end and a pyrene group at the other.In testing their technique, the team found that the maximum OOR current density reached as high as 2.45 mA/cm2 and their device was able to keep half of its ORR current for 120 days. They suggest their results show promise and expect further improvements as they refine the technique. More information: Kamal Elouarzaki et al. Coupling orientation and mediation strategies for efficient electron transfer in hybrid biofuel cells, Nature Energy (2018). DOI: 10.1038/s41560-018-0166-4AbstractEnzymes are promising electrocatalysts for electron transfer (ET) in many biological processes. Strategies to enhance ET between enzymes and electroactive surfaces include orientation and immobilization of the enzymes and electron mediation. Here, we develop a strategy to couple orientation and electron mediation on electrodes based on carbon nanotubes. This is achieved by the synthesis of a redox mediator that contains an enzyme-orientation site (pyrene), an electron-carrier redox mediator (2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS)) and an electropolymerizable monomer (pyrrole). The coupling of an enzymatic orientation and a mediated ET in the same chemical structure (pyrrole–ABTS–pyrene (pyrr–ABTS–pyr)) provides a much-improved performance in the bioelectrocatalysis. We demonstrate two fuel cells for the synthesized redox mediator. In a proton-exchange membrane hydrogen/air fuel cell and in a membraneless fuel cell, the pyrr–ABTS–pyr biocathode provides a power density of 1.07 mW cm−2 and 7.9 mW cm−2, respectively. The principle of coupling an enzyme orientation and a redox mediator allows a great variety of mediators to be engineered and provides vast possibilities for the development of fuel cells.center_img Study explores hybrid ultrasmall gold nanocluster for enzymatic fuel cells 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. The as-designed poly(pyrr)–ABTS–pyr film. a, Representations of Trametes versicolor Lac with the hydrophobic binding pocket oriented towards the bottom of the page and the T1 copper site located on one side of the enzyme at the base of a hydrophobic pocket, which acts as the binding site of the enzyme substrate. The remaining three copper atoms are bound on the T2 and T3 sites in a triangular cluster approximately 12 Å away towards the other side of the enzyme, where oxygen binds. b, Graphical depiction of the ET from the electrode towards Lac through poly(pyrr)–ABTS–pyr film. Credit: (c) 2018 Nature Energy (2018). DOI: 10.1038/s41560-018-0166-4 © 2018 Tech Xplorelast_img read more

A different love tale

first_imgThe 1967 black and white classic Jaatiswar had mega star Uttam Kumar and Tanuja in the lead. The same characters are now reprised by Prosenjit Chatterjee and Jisshu Sengupta, but with a brand new storyline.Jaatiswar is the story of Rohit, a Gujarati brought up in Bengal, who falls in love with a woman who is Bengali with a vengeance – Mahamaya Banerjee. She is obsessed with the Bengali language, hates using English words, loves Bengali poetry, songs and believes in the intellectual superiority of the race. Naturally, she rejects his proposal as he can’t even pronounce her name properly. Also Read – ‘Playing Jojo was emotionally exhausting’When further pushed, she sets a condition and challenges him to write, compose and sing a perfect Bengali song for her, upon which she would consider his proposal. After this, their paths diverge. Mahamaya becomes a RJ who works for a radio station which eventually is entrusted the responsibility of organising a rock concert involving bands from India and Bangladesh. Rohit meanwhile goes to Portugal to study colonial history, and decides to do it on Heynesman Antony, a Portuguese who was born in 19th Century Bengal, who learnt the Bengali language and went on to become of the leading minstrels of that time. Also Read – Leslie doing new comedy special with NetflixIn his fieldwork, he meets a mysterious man, Kushawl Hajra in Chandannagore, Antony’s birthplace. He claims to be Antony’s reincarnation whose memory from the last birth is overpowering his present life memory at a fast rate leading to identity replacement. Rohit starts recording his narrative of his past life as Antony for his dissertation. From here we see a journey of two men separated by one and a half century – both learning an alien language and going on to write songs overcoming all odds, Rohit and Antony. How Rohit woos Mahamaya with the perfect Bengali song, and how Kushawl deals with his psychological disorder forms the rest of this musical-reincarnation drama-biopic -love story. Talking about the film Chatterjee said, ‘I’m really looking forward to the release of this film. Antony Firingee is an iconic character and I’m glad that I got an opportunity to play this character. The storyline however is entirely different from the earlier film. All I can say is that this film has a whole new surprise track weaved in the storyline. The soul of the film is same- it is a musical. The music of this film is divine and I have experimented a lot with my look. In fact, it is a very well researched look.’The film is slated to release in more than 20 cities in India – Bombay, Pune, Thane, Vashi, Delhi, Bangalore, Jamshedpur, Dhanbad, Hyderabad, Ahmedabad, Baroda, Jaipur, Chandigarh, Lucknow, Patna, Indore, Raipur, Guwahati, Bhubaneshwar and Chennai. Outside Bengal, the film will be released with English subtitles.When: Premiering 17 January, pan Indialast_img read more

One killed 7 others critically injured in bus accident near Kasba

first_imgKolkata: Two minibuses racing against each other to pick up extra passengers once again claimed the life of a 50-year-old man and injured eight others of whom some are critically ill.The incident took place near Acropolis Mall at Kasba on Tuesday morning. A Howrah bound minibus from Anandapur was competing with another minibus of the same route when the bus driver lost control over the vehicle and eventually hit a Mercedes car parked by the side of the road and then rammed into two auto-rickshaws which were there at the stand. Also Read – Heavy rain hits traffic, flightsBiswanath Haldar (50), a resident of Noanadanga area was standing by the side of the car waiting to board a bus when he was hit.Haldar who runs a decorators business suffered critical injuries after being hit by the speeding bus. Seven others including a woman who were standing by the side of the road also suffered injuries. An on duty police sergeant who was standing at the spot had a narrow escape. The speeding bus also ran over the pavement injuring some people who were standing there. The health condition of the woman is stated to be critical. The incident created traffic jam in the area for a while. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedHaldar and other injured passengers were rushed to a nearby private hospital where Haldar succumbed to his injuries while the others have been undergoing treatment in the hospital. The news of Haldar’s death has set a pal of gloom in his family as he was only the bread earner. According to police, there were none inside the Mercedes car when it was hit by the bus. The owner of the car Vinod Sharma, a Salt Lake resident went to the Passport office by parking the vehicle on the side of the road. The rear portion of the costly car was completely damaged in the accident. Two auto-rickshaws were also damaged in the accident. Eyewitnesses told the police that the accident occurred when the killer vehicle was competing with another minibus of the same route. Locals expressed their unhappiness over the unabated incidents of racing of buses which often lead to death. Senior police officers reached the spot immediately after the accident. The bus driver has fled the spot leaving the vehicle there. Police have seized the bus and are yet to arrest the driver.Meanwhile, an auto-rickshaw driver has been arrested by the Bidhannagar police after he broke the wind screen of a state-run AC bus. The incident took place near Baguiati More on the VIP road. The accused told the police that the bus driver was not giving him any scope to overtake it. He stopped the bus and ransacked a portion. One passenger was reportedly injured when the wind screen was broken.last_img read more

Myths and facts about dental care

first_imgIs scaling bad for teeth? Are cavities caused only by sugar? An expert separates fact from myth.Tanvir Singh, consultant orthodontist at Dentem, the Dental and Orthodontic Clinic, busts a few myths around dental care:Myth 1:Scaling is not good for teeth.Fact: Scaling removes tartar and keeps teeth and gums healthy. Scaling and deep cleaning of gums prevent the problem of bad breath and bleeding gums. Thus, scaling is beneficial for teeth and gums. One should get professional cleaning done by a dentist with a proper ultrasonic scaler. Also, getting extensive scaling (more than required) done is harmful. Also Read – ‘Playing Jojo was emotionally exhausting’Myth 2:Only sugar causes cavities.Fact: Cavities occur when bacteria produce acids in the mouth. The process can begin by any carbohydrate that you consume. That includes sugar, fruits, vegetables, rice and bread. To reduce chances of tooth decay, one should not only practice good dental care but also limit the intake of acidic products.Myth 3:Teeth whitening is harmful as it damages enamel.Fact: Technique like Zoom Whitening works by exfoliating stains from one’s teeth to lighten them and bring back their natural colour. It is the simplest and safest procedure as a product is used by dentists that is devoid of bleaching agents and chemicals. Also Read – Leslie doing new comedy special with NetflixMyth 4:Brushing your bleeding gums is bad.Fact: Brushing is not only good for teeth, but also for your gums and tongue. Brushing these areas helps get rid of plaque which is what causes inflammation and eventually gum disease. One should not brush too hard if they have sensitive gums. One must not use a hard toothbrush on bleeding gums.Myth 5:Using sugarless chewing gum after meal can replace brushing. Fact: Nothing can replace proper brushing technique. And in case you want to use sugarless chewing gum, do not chew it for more than 10 minutes.last_img read more

SC verdict on panchayat poll victory of democracy people Mamata

first_imgKolkata: Dubbing the Supreme Court verdict on West Bengal panchayat poll as a “victory of democracy and of the people”, Chief Minister Mamata Banerjee today slammed the BJP, the Congress and the CPI(M) for “defaming” the state through false propaganda. It was a planned move by the three political parties to gain political advantage, Banerjee said. Welcoming the Supreme Court’s verdict, she said these parties had deliberately resorted to false propaganda. Also Read – Rain batters Kolkata, cripples normal life “I think it is a victory of democracy and victory of the people. I want to dedicate it to the people of the country,” Banerjee told reporters at the state secretariat. She said the CPI(M) and the BJP moving the Supreme Court seeking cancellation of elections in over 20,000 uncontested local body seats in West Bengal had brought bad name to the state. “It was a planned move by the CPI(M), the Congress and the BJP to malign the state and they have been doing it continuously,” Banerjee, also the Trinamool Congress chief, said. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killed The Supreme Court has turned down the pleas of the CPI(M) and the BJP seeking cancellation of elections on over 20,000 uncontested local body seats in West Bengal. All the uncontested seats were won by candidates of the ruling Trinamool Congress (TMC). The CPI(M) and the BJP, which opposed the contention of the state government, state poll panel and the TMC, had alleged that West Bengal did not witness a free and fair election and the candidates of these two parties were stopped from filing nomination papers. Elections were held in phases for 48,650 posts in Gram Panchayats, 825 posts in Zilla Parishads and 9,217 posts in Panchayat Samitis and the TMC won about 34 per cent seats uncontested.last_img read more

Choir singing helps to fight cancer

first_imgChoir singing can be useful in fighting against deadly diseases, reveals a study adding that the group activity can help put people in the best possible position to receive treatment, maintain remission and support cancer patients According British researchers, singing in a choir for an hour is associated with significant reduction in stress hormones — cortisol and increase in quantities of cytokines — proteins of the immune system, which can boost the body’s ability to fight serious illness. Also Read – ‘Playing Jojo was emotionally exhausting'”We have been building a body of evidence over the past six years to show that singing in a choir can have a range of social, emotional and psychological benefits and now we can see it has biological effects too,” said study co-author Ian Lewis from Tenovus Cancer Care in Britain. “This is the first time it’s been demonstrated that the immune system can be affected by singing. It’s really exciting and could enhance the way we support people with cancer in the future,” Lewis added in the paper published in the journal ecancermedicalscience. The findings suggested that singing activity could reduce some of this stress-induced suppression, helping to improve wellbeing and quality of life amongst patients.last_img read more