Nanodevices could use quantized current to operate future electronics

first_img Citation: Nanodevices could use quantized current to operate future electronics (2007, November 26) retrieved 18 August 2019 from 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. For the past several decades, virtually all electronics devices have been based on the CMOS logic system, which uses semiconductors and transistors to form digital circuits. However, researchers today are investigating the use of novel materials and technologies to create superior circuitry, which would lead to smaller, faster and smarter computers, cell phones, and other devices. Explore further Producing graphene from carbon dioxide Then, the researchers suggested how PTTGs made in either of these two ways could be used to create universal logic gates. Due to the flexible quantization characteristics of the current-quantization devices, a single PTTG could implement nearly all 256 three-input Boolean functions (the most common computing method in digital electronics). Also, two PTTGs put together could implement all 65,536 four-input Boolean functions. “The quantized current devices have several quantization states that can be used to represent discrete logic states,” Zhang explained, “while conventional CMOS transistors have only two logic states: on and off. That’s why the quantized current device can enable complicated and compact periodic-threshold threshold logic gates.”The researchers also explained that the current-quantized logic gates could have several advantages over conventional logic gates. For one thing, they have both a simple and more universal circuit structure. Compared to the 40 transistors required by a conventional three-input logic gate, a PTTG would only require 10 equivalent devices. Further, the two current-quantized logic gates both have very small sizes, offering the potential for high density circuitry. Finally, due to their small size and low resistance, the new logic gates may also have a significant speed advantage.“The key to achieving quantized current devices is small device geometry,” Zhang said. “Both the ballistic transport of electrons in electron waveguides and the Coulomb-blockade effect in the single-electron turnstile require small device geometry to overcome the thermal energy. With recent advances in fabrication, room-temperature operations of the electron waveguide and single-electron turnstile are possible.”More information: Zhang, Wancheng, Wu, Nan-Jian, and Yang, Fuhua. “Compact universal logic gates realized using quantization of current in nanodevices.” Nanotechnology 18 (2007) 495201 (8pp).Copyright 2007 All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of Most recently, scientists Wancheng Zhang, Nan-Jian Wu, and Fuhua Yang from the Chinese Academy of Sciences in Beijing have designed logic gates—a basic component of digital circuits—that use the quantization of electric current to perform operations. The recent development of two unique nanodevices has enabled scientists to control the flow of individual electrons, allowing the team to propose novel universal logic gates that are more compact than conventional logic gates.“When talking about future digital circuits using nanodevices, researchers usually focus on their potentially high density and fast speed,” Zhang told “The greatest significance of this work is that we show that the unique operating principles of novel nanodevices can be used to implement smarter logic circuits with very compact structures. Therefore, future nano-based-circuits can have advantages both in size and in circuit structure.”In their study published in Nanotechnology, the researchers proposed two different designs for building “periodic-threshold threshold logic gates” (PTTGs). In the first method, the researchers proposed using an electron waveguide—which is essentially a one-dimensional channel—to take advantage of the wave nature of the electron. Because the channel is narrower than a single electron, an electron wave can travel through the channel without scattering, in a discrete number of modes. By using two of these electron waveguides, and combining their current values, the logic gate could have an output consisting of the combined input currents.In the second method, the scientists proposed a PTTG using a single-electron turnstile, a device that can accurately control the number of transferred electrons using a quantum effect called the Coulomb-blockade effect. This effect, which only exists in a tiny area about the size of a single electron particle, ensures that the number of electrons transferred by the turnstile is a quantized function of its voltage. By controlling the voltage, the researchers could theoretically determine the number of captured electrons, and use two single-electron turnstiles to transfer electrons to a storage node, with the difference of electrons between the two turnstiles determining the output signal.last_img read more

Scientists use AI cobweb analysis to determine spider species

first_img Explore further Spider web samples of the four species: (a) Allocyclosa; (b) Anapisona simoni; (c) Micrathena duodimspinosa; (d) Zosis geniculata. Credit: Expert Systems with Applications, Volume 40, Issue 10 Joshua Tree spider species named for U2’s Bono ( —The identification of spider species based on pattern recognition of their cobwebs has been shown to be quite possible and successful. The paper, “Spider specie identification and verification based on pattern recognition of it cobweb,” was published in Expert Systems and Applications and the paper’s research was also recently discussed in New Scientist. A team came up with an AI cobweb recognition system through the use of special software for analyzing images supplied by a spider expert. More specifically the team used images from William Eberhard of the Smithsonian Tropical Research Institute in Costa Rica. Citation: Scientists use AI cobweb analysis to determine spider species (2013, March 28) retrieved 18 August 2019 from Carlos Travieso at the University of Las Palmas de Gran Canaria in Spain and colleagues applied their pattern recognition techniques on the pictures until they were confident they had a reliable means of identifying which species spun which type of web. According to New Scientist, they were able to achieve “astonishing” accuracy in species recognition, hitting 99.6 per cent, Their method involved principal component analysis (PCA), independent component analysis (ICA), Discrete Cosine Transform (DCT), Wavelet Transform (DWT) and discriminative common vectors such as features extractors, according to the study. Interestingly, PCA provided the best performance, reaching a 99.65% ± 0.21 of success rate in identification mode and 99.98% ± 0.04 of the area under Receiver Operating Characteristic (ROC) curve in verification mode; the best combination of features extractors was PCA, DCT, DWT and ICA, which achieved a 99.96% ± 0.16 of success rate in identification mode and perfect verification. The value of their research tool extends from a way of measuring spider species to understanding and measuring biodiversity. In a previous discussion on spider classification last year, Travieso and colleagues noted the great effort under way in the scientific community to study biodiversity on the planet, yet spiders were one of most unattended groups in biology. They said the arachnids are not only plentiful but they are also ecologically crucial in almost every terrestrial and semi-terrestrial habitat. Spider webs, meanwhile, carry an incredible amount of information, they added, which can be used for the automatic classification of spider species. The researchers are now aiming to count other species of animals and insects. © 2013 More information: Spider specie identification and verification based on pattern recognition of it cobweb, Expert Systems with Applications, Volume 40, Issue 10, August 2013, Pages 4213–4225. conservation is a global priority where the study of every type of living form is a fundamental task. Inside the huge number of the planet species, spiders play an important role in almost every habitat. This paper presents a comprehensive study on the reliability of the most used features extractors to face the problem of spider specie recognition by using their cobwebs, both in identification and verification modes. We have applied a preprocessing to the cobwebs images in order to obtain only the valid information and compute the optimal size to reach the highest performance. We have used the principal component analysis (PCA), independent component analysis (ICA), Discrete Cosine Transform (DCT), Wavelet Transform (DWT) and discriminative common vectors as features extractors, and proposed the fusion of several of them to improve the system’s performance. Finally, we have used the Least Square Vector Support Machine with radial basis function as a classifier. We have implemented K-Fold and Hold-Out cross-validation techniques in order to obtain reliable results. PCA provided the best performance, reaching a 99.65% ± 0.21 of success rate in identification mode and 99.98% ± 0.04 of the area under de Reveicer Operating Characteristic (ROC) curve in verification mode. The best combination of features extractors was PCA, DCT, DWT and ICA, which achieved a 99.96% ± 0.16 of success rate in identification mode and perfect verification.via Newscientist 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

Researchers find it is possible to use cyanate as an energy source

first_img © 2015 For many years, scientists have believed that microorganisms that serve as ammonia oxidizers drive the nitrification process, because it was believed they were the ones that created the food for nitrite oxidizing microorganisms. Now it appears that such thinking might have to be modified, as the researchers with this new effort have found an example of an ammonia-oxidizing thaumarchaeote (organisms of the Archaea phylum), Nitrososphaera gargensis1, that uses cyanate as the one and only source of energy and reductant—showing that nitrite oxidizers can provide the food for ammonia oxidizers. Thus it appears to go both ways.The team made the discovery while conducting genome tests of nitrite oxidizers—they found genes that encode for cyanase, an enzyme that is known to break down cyanate, a sign that they likely could use cyanate as an energy source. To find out for sure, they conducted an aerobic growth of N. gargensis1 (an ammonia oxidizer) using just cyanate, proving that it could be done—it is now classified as the only organism able to carry out such a process.The findings by the team are an important discovery because it will help scientists better understand the nitrogen cycle in general and the nitrification process more specifically—and that should help to better understand the issues involved in solving such problems as unabated nitrification that occurs due to over fertilization of croplands leading to pollution and dead zones in the sea. And as Stein, notes, we have entered a time where human production of fixed nitrogen is greater than that produced naturally with the result being a nitrogen cycle that is now unbalanced—suggesting, perhaps that leveraging organisms such as N. gargensis1 could help restore that balance. More information: Nature (2015) DOI: 10.1038/nature14856 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: Nature Explore further Nitrogen loss in soils unearthed Citation: Researchers find it is possible to use cyanate as an energy source for nitrifiers (2015, July 31) retrieved 18 August 2019 from An international team of researches has found an example of a nitrite oxidizing organism that can convert cyanate into ammonium and carbon dioxide. In their paper published in the journal Nature, the team describes their research which had both a genetic component and field experiments, and why they believe what they found might make the case for cyanate being classified as a key controller of the nitrification process. Lisa Stein of the University of Alberta offers a News & Views piece on the work done by the team, in the same journal edition.last_img read more

Cooch Behar among top districts performance wise

first_imgKolkata: Cooch Behar has done remarkably well in 100 days’ work and is likely to be among the top districts in performance.The district magistrates of different districts had given power point presentation before the senior officials of the ministry of Rural Development in New Delhi on Saturday. The officials have expressed their satisfaction and a team will visit the districts soon.Six districts, Jhargram, Bankura, East and West Midnapore, Cooch Behar and Jalpaiguri have done remarkably well in 100 days’ work. Also Read – Heavy rain hits traffic, flightsKaushik Saha, district magistrate said: “The work has been carried out following the instruction of Chief Minister Mamata Banerjee. She has been the source of inspiration.”It may be mentioned that Banerjee had expressed her concerns when she found out that Cooch Behar district had given work for 28 days to the job card holders in 2017-18. Saha was holding a meeting at Uttarkanya and instructed the district magistrate to take up the matter seriously. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedFollowing the initiative taken up by Saha, the number of days given to the job card holders has gone up to 58. The district is also doing well in livelihood programmes.It may be mentioned that the state government has given instructions to all the district magistrates to immediately resume programmes under 100 days’ work, which had been suspended due to the three tier Panchayat elections, resulting in delay by 45 days. As the elections are over, the districts are now making hectic arrangements to reach the target.last_img read more

Agriculture dept initiates steps for yearround training to farmers

first_imgKolkata: Following Chief Minister Mamata Banerjee’s direction, the state Agriculture department has initiated all necessary steps to ensure round-the-year training programmes for farmers at Mati Tirtha in Burdwan.Asish Banerjee, the state Agriculture minister, will be visiting Mati Tirtha on June 24, to take a stock of the situation and would discuss the issues related to it with the concerned officials.It may be mentioned that Mati Tirtha in Burdwan is the permanent venue of Mati Utsav that takes place every year in January. The Chief Minister felicitates successful farmers from different parts of the state in the programme. Also Read – Heavy rain hits traffic, flightsMati Tirtha is spread over a large area as the Chief Minister had directed to take necessary steps so that seminars, programmes and symposiums related to agriculture and its allied departments can be held at the place.The requirement of organising such programmes was felt, in ensuring that farmers keep getting regular updates and can implement the same while carrying out agricultural activities.With the initiative taken by the state government, a team comprising senior officials of the Agriculture department visited Mati Tirtha on June 13. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThey have prepared a report and there was detailed discussion to ensure presence of all sorts of infrastructure at Mati Tirtha, which is necessary to carry out round-the-year training of farmers.Sources said that some other departments can also organise training programmes at Mati Tirtha and they have also been approached.The state government has witnessed massive development in the agriculture sector in the past seven years, with several steps taken by Mamata Banerjee after coming to power in 2011. The steps have ensured a growth in production of paddy and at the same time, the area for cultivation of crops has also been increased.Innovations have also taken place in this sector, with research stations under the state Agriculture department working on different aspects of the sector.The state Agriculture department often organises programmes to aware farmers about new techniques and schemes. Now, the step has been taken up for their round-the-year training at Mati Tirtha. Farmers will be immensely benefitted with initiation of the same.It may be recalled that Mamata Banerjee had initiated the Mati Utsav to celebrate the success of farmers in the state and at the beginning, it used to take place at Panagarh and later it was shifted to its permanent venue at Mati Tirtha.last_img read more

Govt to sign MoU with British Council to promote exchanges

first_imgKolkata: The state government is going to sign a memorandum of understanding (MoU) with British Council to promote cultural, educational and skill development exchanges between Britain and Bengal.Expressing her happiness over the matter, Chief Minister Mamata banerjee tweeted: “I am happy to share with all of you that British Council and Govt of West Bengal are going to sign a MoU to promote cultural, educational and skill development exchanges between Britain and Bengal.” Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedAmong the salient features under the MoU are celebration of Durga Puja in the UK during Thames Festival, hosting of a River Festival in Kolkata similar to the Thames Festival in the UK, exchanging visitors between the UK and Bengal for cultural exchanges, collaboration on skill development, communication in English and overall enhancement of employability of the youth.She further tweeted: “I had raised these issues during my visit to the UK, after which Baroness Usha Prashar, Member of the House of Lords and Global Deputy Chairperson of British Council, had come to Kolkata to take the initiative forward.” Also Read – Naihati: 10 councillors return to TMC from BJPIt may be mentioned that the state government has taken a slew of measures to attract foreign tourists. A grand carnival is organised on Red Road to see off Durga idols before immersion and some of the best idols are preserved at a museum in Eco Park.Heritage walks are being organised regularly by private tour operators in North and Central Kolkata and the walks have gained immense popularlity among foreign tourists. The state government is also planning to introduce tea and religious tourism to woo global tourists.last_img read more

Sensex recoups 291 points after mega plunge

first_imgAfter correcting severely yesterday, Indian market staged a smart recovery today as the benchmark BSE Sensex spurted by 290.82 points to 26,032.38 on value- buying in realty, metals and banking stocks amid hopes that government might convene a session for passage of GST bill.Moreover, recovery in rupee, which sharply appreciated by 76 paise to 65.89 intra-day against the dollar also supported sentiment, brokers said.Trading in a wide range of 826.35 points during the day, the index managed to reclaim the 26,000-level after falling to its lowest since August 8, 2014, clocked in the previous trading. Also Read – Need to understand why law graduate’s natural choice is not legal profession: CJIThe BSE Sensex, which opened in the positive zone rallied to touch day’s high of 26,124.83 briefly, but slipped into the negative zone as selling pressure re-emerged and fell to a low of 25,298.42.However, towards the middle of the day, it staged another comeback to close the session 290.82 points or 1.13 per cent higher at 26,032.38.In the previous three sessions, the index lost 2,190.08, including yesterday’s biggest-ever fall of 1.624.51 points. Also Read – Health remains key challenge in India’s development: KovindThe NSE Nifty index also jumped 71.70 points or 0.92 per cent to end at 7,880.70. Intra-day, it reclaimed the 7,900 mark to touch a high of 7,925.40 and a low of 7,667.25.Equity brokers said sentiments got a boost after the government said, to pass key reform bills, including GST, it might reconvene the Monsoon Session.Market volatility was also high in view of August month expiry in the derivatives segment on Thursday.Among 30-Sensex stocks, 22 ended with gains led by Vedanta, Tata Motors, Coal India, ICICI Bank, Axis Bank, NTPC, Tata Steel, GAIL, SBI, RIL, BHEL, Dr Reddy’s and Hindalco. Barring IT, all the BSE sectoral indices notched up gains led by realty, metal, oil& gas, PSU and banking.Retail investors pumped money into mid-cap and small-cap shares with respective indices rising up to 1.99 per cent.Globally, most Asian bourses closed mixed with Chinese equities sliding by 7.63 per cent. A higher opening was seen in European markets.last_img read more

Dont run away from fixing responsibility Shatrughan tells BJP

first_imgActor and BJP’s Lok Sabha member Shatrughan Sinha on Thursday said that the party should not run away from fixing responsibility in the Bihar debacle and warned party leaders not to treat him like a Rajya Sabha member with no support base.”…now that the (Bihar assembly elections) verdict is out and we’re saddened by this humiliating defeat, we should not run away from fixing responsibility,” Sinha tweeted.The Bollywood veteran’s comment came after the BJP old guard, including L.K. Advani and Murli Manohar Joshi, on Tuesday demanded a thorough review of the debacle and said it cannott be done by those who were responsible (for the electoral defeat). Also Read – Punjab on alert after release of excess water from Bhakra damSinha, a former union minister, also warned party leaders not to treat him like a Rajya Sabha member, and reminded them that he has a support base.”I am not a Rajya Sabha MP. I’ve come through the support of the masses and (have) won two Lok Sabha elections with record margins. I have a support base,” he said.Sinha said despite his sincerity, efforts and intentions, he was kept away from campaigning in the Bihar assembly elections.”My friends, voters and supporters were let down,” he said.Sinha said he never wanted to be the chief minister of Bihar, but insisted the election results would have been different if he was allowed to campaign in the state.He reiterated he had not worked against the BJP in any way. There have been rumours that the party might take disciplinary action against him for alleged “anti-party” activities.last_img read more

Representing the best of art and culture

first_imgIn order to promote classical music and dance and to highlight its importance in Indian Cinema, ‘Saniddhya’ (a cultural society) will organise classical music and dance festival and seminar –’A Contribution of Indian Classical Music and Dance in Indian Cinema’ at Palika Park in the national Capital from February 4-5. Kamal Kumar, Secretary of ‘Saniddhya’ said: “Since 2000, ‘Saniddhya’ is working for promoting Indian art and culture as well as working for social issues through art and culture.”The first day of the event will see a group presentation of Saniddhya by young artists, solo performance by Shikha Khare Kathak exponent and disciple of Kathak Maestro-Padma Vibhushan Pt. Birju Maharaj Ji, Sufi Divine Qawwali Group, Manju Wazir Dance Group, solo performance by Khayti kalia kathak exponent, a group dance performance by Sushmita Kanjilal, group performance by Maa Saraswati Music and Dance Academy.A group dance performance by Shadja Foundation, solo and trio dance presentation by Saniddhya Repertory artists, a group dance performance by Dharohar academy, Bollywood classic singing performance by Manaya, a dance presentation by Lekha Sharma, a group dance performance by Nritya Bharti Kalapeeth and melody singing performance by Vishuddh Band, will be the main attractions on the second day of the event.WHEN: February 4-5WHERE: Palika Park, C.P.TIMINGS: 6 pm to 9 pmlast_img read more