In new hybrid chip molecules are memories

first_img New record: 3-D-printed optical-electronic integration As scientists strive to satisfy the growing demand of the digital era for faster, smaller, and cheaper electronics, one of the most promising technologies is hybrids. Hybrid ICs (integrated circuits) consist of a combination of different technologies: micro, nano and molecular. Although currently scientists still face a handful of challenges in the development of hybrid ICs, the technique looks promising to produce the one of the highest memory densities yet – a whopping 100 billion bits per square centimeter. As the team wrote, their first major problem they face is “the set-up of economically sustainable technology for the preparation of 1011 cross-points cm-2.” For problems such as synthesizing and grafting the molecules, as well as organizing the writing linkages in the microelectronic circuit, the scientists offered low-cost solutions (e.g. using self-alignment rather than expensive electron beam lithography) to achieve the necessary scaling. Considering the number of parts on a chip – 10 billion bits, 200,000 wires, 256 sense amplifiers and ten million transistors occupy each crossbar of area 2.5 square cm – such scaling is no small feat (figuratively speaking, at least). Although other questions – such as reliability of the molecules –would require further specifications, Cerofolini and Mascolo conclude that micro-nano-mole ICs have potential.“That ‘potential’ does indeed transform into ‘practical’ requires that the techniques of deposition, oxidation and anisotropic etching be integrated in a cluster tool permitting the repetition of the unit cycle in a relatively short time,” the scientists wrote. “…and that the chemical, rheological, etc. properties that are observed on the submicrometer length scale continue to hold true on the nanometer length scale.”Citation: Cerofolini, G. and Mascolo, D. “A hybrid micro-nano-molecular route for nonvolatile memories.” Semiconductor Science & Technology. 21 (2006). 1315-1325.By Lisa Zyga, Copyright 2006 This hypothetical molecule is a candidate for mimicking a flash memory cell. In Cerofolini and Mascolo’s design, thousands of molecules are grafted to the silicon structure at each cross point. Photo credit: Cerofolini, G. et al. Explore further In this cross-section of a portion of the hypothesized hybrid micro-nano-molecular IC, a crossbar (vertical lines) is placed on top of conventional CMOS circuitry. The inset drawing shows the molecules that link the lower and upper sides of the crossbar and “mimic the behavior of a flash memory cell.” Photo credit: Cerofolini, G. et al.center_img “These hypothesized molecules are able to mimic the structure and functioning of a flash memory cell,” the team wrote. “If the molecule admits two electronic states characterized by largely different conductivity … the whole structure may be viewed as a hybrid nano-micro IC with bit density of the order of 1011 cm-2.”The challenges that Cerofolini and Mascolo identified generally revolve around two aspects: production cost and scalability. In the IC industry, money is spent on the front side of the process: if you can design the architecture for a sufficiently small (i.e. dense) chip at a feasible assembly cost, there will be enough uses (computers, cell phones, PDAs, etc.) that profits will more than make up for design costs. Citation: In new hybrid chip, molecules are memories (2006, August 8) retrieved 18 August 2019 from In preparation for fabricating hybrid ICs, scientists Gianfranco Cerofolini and Danilo Mascolo from STMicroelectronics in Italy have analyzed the current state of the required technologies. They then defined and generated solutions for the greatest challenges, and predicted the most successful route to mass fabrication of hybrids for nonvolatile memories (which is memory that can be stored even after power is turned off, e.g. flash). “We have proposed an architecture allowing the mass scale production of hybrid ICs on the 0.1 Tbit [trillion] integration scale,” wrote the team in a recent issue of Semicounductor Science & Technology. “All solutions to factors limiting the development of the technology require the adaptation of already existing technologies to the proposed architecture.”In their hybrid set-up, the scientists start with a microelectronic silicon part, which controls a nano crossbar, where each cross point hosts up to 10,000 molecules – hence, a “micro-nano-mole IC.” It’s the individual molecules that act as memory devices, as they can have two different electrically conductive states (low and high) which code the bits. A molecule captures an electron, causing a current to save the state by switching off writing potential. To erase, the captured electron can be forced to tunnel away. (Electron tunneling, an effect of quantum mechanics, occurs due to the wavelike nature of electrons, enabling the particles to “tunnel” across a forbidden zone and emerge in a different position, not actually having been in between.) 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

Male St Andrews Cross spiders sniff web pheromones to determine suitability of

first_img Explore further More information: Can males detect the strength of sperm competition and presence of genital plugs during mate choice? Behavioral Ecology (2014) DOI: 10.1093/beheco/aru045AbstractFemale reproductive status can have strong selective effects on male mating strategies due to the threat of sperm competition, which may explain why males prefer virgin over mated females. However, in mating systems with female multiple mating rates and mating plugs, males should not only respond to the risk but also to the level of sperm competition and should be sensitive to the interference from mating plugs. In the orb-web spider Argiope keyserlingi, females possess paired sperm-storage organs facilitating separate sperm storage from different males. Males are limited to 2 copulations due to mutilation of their paired genitals (pedipalps). By conducting binary choice experiments, we tested whether males of different mating status can distinguish between females that mated with 1 or 2 males and whether single-mated males discriminate between single-mated females with matched or unmatched virgin genital openings. Furthermore, we investigated whether males adapt their mating strategies to the intensity of sperm competition by providing males with varying qualities of females in their immediate vicinity. Our results demonstrated that males are sensitive to the level of sperm competition and preferred single-mated females over double-mated females. However, they failed to identify single-mated females whose virgin genital opening matched their unused pedipalp, which is required due to their fixed ipsilateral insemination. Surprisingly, males never mated twice with the same female independently of the quality of surrounding females. This suggests that the benefits from searching and mating with a different female are greater than the benefits of monopolizing the female by mating twice with her. © 2014 Journal information: Behavioral Ecology 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. Argiope keyserlingi. Credit: James Niland/Wikipediacenter_img ( —A trio of researchers, two with the University of Hamburg in Germany and a third with Macquarie University in Australia has discovered that male St. Andrew’s Cross spiders sniff the webs of female spiders to determine if they are suitable for mating attempts. In their paper published in the journal Behavioral Ecology, the team describes how they conducted experiments on several specimens of the species in their lab and discovered that male spiders could “smell” pheromones on the females web and used that information in deciding whether to attempt copulating with them or not. St. Andrew’s Cross spiders of both genders have dual sex organs—a left and a right. To copulate, the organs from both genders must match, i.e. right male to right female or left to left, or things won’t work. Furthermore, when a male mates with a female, his organ (pedipalp) breaks off, forming a plug preventing other males from mating with that female’s organ. The end result is that both genders can only mate twice.But how do male spiders know if a female has already mated twice? Climbing onto her web for a closer look is dangerous, if the (much larger) female is hungry, she’s likely to eat the intruder if both of her organs are plugged. To find out, the researchers placed a male on a wooden peg that two females had used to anchor their webs. The researchers found that the male was able to tell if the female was done mating by simply sniffing her web—he was able to pick up telltale pheromones, and thus avoid the females that provided no reproductive opportunity. Sadly, the sniff test was not able to also tell the male if he and the female had compatible organs remaining (left to left or right to right) for mating, thus, there was still some degree of risk in venturing onto the web.Interestingly, the team also found that the males also would not mate with the same female twice, regardless if all other females in the vicinity were incompatible or already doubly mated. Such a strong predisposition suggests the urge to spread genes was stronger even than the urge to procreate. Citation: Male St. Andrew’s Cross spiders sniff web pheromones to determine suitability of female mates (2014, March 31) retrieved 18 August 2019 from Male dark fishing spiders found to die spontaneously after matinglast_img read more

Clear stretches across less populated areas hub of speed driving

first_imgKolkata: Straight stretches of national highways which pass through thinly populated areas have become the hotspots for a section of owners of high-end cars and motorbikes for “recreational speed driving” on Sundays. There are a section of people who flout norms even when Bengal has come up as one of the best states in checking road accidents and creating awareness among people with Chief Minister Mamata Banerjee’s statewide campaign of Safe Drive Save Life. Also Read – Heavy rain hits traffic, flightsVivek Sahay, ADG (Traffic and Road Safety), said: “Many people have a wrong notion that there are no speed limits on expressways or highways. It is on that basis that they seek to justify speed driving. But it is not so. There are speed limits for all vehicles.”It may be mentioned that there is a group of people in and around Kolkata who have formed clubs and go out with their high-end expensive cars or two-wheelers for “recreational speed driving,” especially on Sundays. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThere are stretches on National Highway 2 which are straight and pass through thinly populated areas. The stretch mainly falls under the jurisdiction of Jamalpur, Memari, Burdwan and Galsi police stations and is straight where vehicles can be plied at high speed. Another such stretch is at Gurap in Hooghly.Concerned senior police officers have recently visited the spots in this connection. Interestingly, there are around 3,500 cars in Kolkata which cost more than Rs 90 lakh. Some of these cars cross 500 hp in power output and can easily cross 200 km per hour. Police maintain a vigil to avoid over-speeding of vehicles and the number of prosecution cases for the same has also gone up manifold compared to that of the past few years. It is not only the case of high-end vehicles but any vehicle that over speeds comes under the purview of prosecution. Last year only 75 speed cameras were installed in districts to check speeding and it resulted in a major drop in road accidents.last_img read more

Former footballers body found on railway tracks near Lake Gardens

first_imgKolkata: Mystery shrouds the death of a former footballer whose body was found on the railway tracks near Lake Gardens in the Sealdah – Budge Budge section on Friday night.The police are yet to confirm if the victim had committed suicide or there was any foul play behind his death. The victim, Ranjit Chatterjee, used to play football for Calcutta Port Trust but could not continue as poverty played spoilsport and his dream remained unfulfilled. According to the police, the victim went abroad to take training in football. A great lover of the game, Chatterjee had bought an auto-rickshaw around two years ago and used to earn his living by driving the vehicle. But he never de-associated himself with the game and began imparting football training to children of his locality and nearby areas. Also Read – Heavy rain hits traffic, flightsThe family members are in shock. They are yet to believe that a strong character like Chatterjee who had tremendous determination and will-power would throw himself in front of the running train and end his life. A complaint with the local police station has been lodged mentioning the names of some persons who, the family suspects, might have been involved in the death of the former footballer. According to the investigation, the cops came to know that he had left home at around 8.30 pm on Friday after watching the World Cup match between Brazil and Costa Rica. The family members received a phone call saying that his body was found lying near the railway tracks at Lake Gardens station. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe locals also told the police that the victim was never involved in any quarrel with anybody and was a good-natured person. They could not imagine that a man of such character could commit suicide. The police have, however, started a detailed probe on the basis of the complaint lodged by his family members. The investigators also collected samples from the spot to determine the nature of his death. The body has been sent for post-mortem, the result of which might throw light on the footballer’s death.last_img read more

Huge amounts of contraband seized in June SER

first_imgKolkata: The South Eastern Railway’s (SER) strict vigil has resulted in seizure of huge amount of contraband goods in the month of June.”Our Railway Protection Force (RPF) team has successfully kept on guarding therailway properties againsttheft and other crimes. During the month of June 2018,RPF personnel have done a lot of security work to foilthe criminal activity over four divisions of this railway,” a senior SER official said.The official added that in the month of June, RPF has seized 900 grams of opium, 25 kg ganja, 240 bags of bhang and 18 bottles of foreign liquor along with 24 bundles of kendu leaves. Also Read – Rain batters Kolkata, cripples normal life”We have also recovered as many as 43 bags with valuables of passengers who had reported loss of the same,” an RPF officer said.The RPF have arrested as many as 18 criminals for theft of passenger belongings at different stations under SER. 46 offenders were arrested under the RP (UP) Act for unlawful possession of railway property and an amount of Rs 2,57,820 was realised.They have also rescued as many as 20 minor boys and 22 minor girls and handed them over to their parents with the help of an NGO.”We have been able to book 5,500 offenders including 2 touts and 631 unauthorised vendors/hawkers under different sections of the Railway Act with realisation of fine amounting to Rs 11, 63, 810. 23,879 ticketless travellers were apprehended during the joint drives conducted by RPF and Commercial Department and an amount of Rs 48,66,135 was realised as fine from them,” an SER official said.last_img read more

Boredom can make you politically radicalised

first_imgIf you are bored and are unable to find a meaning in what you do, chances are you may develop extreme political views sooner, a study reveals. Boredom may be contributing to a widening of political views among voters, according to researchers from King’s College London and the University of Limerick.“Boredom puts people on edge. It makes them seek engagements that are challenging, exciting, and that offer a sense of purpose. Political ideologies can aid this existential quest,” said Dr Wijnand van Tilburg from King’s College London. Boredom motivates people to alter their situation and fosters the engagement in activities that seem more meaningful than those currently at hand, he added.  Also Read – ‘Playing Jojo was emotionally exhausting’Published in the European Journal of Social Psychology, the findings are based on one experiment and two scientific surveys carried out in the Republic of Ireland.In their initial experiment, the researchers recruited 97 people from a university campus. The participants first indicated their political orientation (whether they considered themselves liberal or conservative) before being randomly assigned to complete either a task deemed to be highly boring or a comparatively less boring task. Also Read – Leslie doing new comedy special with NetflixThose assigned to the high boredom group transcribed 10 references about concrete mixing, while those assigned to the low boredom group only had to transcribe two of these references. After completing the boring tasks, the researchers asked the participants to describe their political orientation once again. However, this time the participants indicated their political orientation on a seven-point scale. The researchers found that liberals in the low boredom group were more moderate in their political orientation, compared to liberals in the high boredom group. A similar trend was found for conservatives, though it was not statistically significant as there were only 26 politically right-wing participants, which reduced the study’s statistical power. The study authors also conducted a survey of 859 people living in Ireland and found that people who were easily bored tended to endorse more extreme political views. Another survey of 300 people found that being prone to boredom was associated with searching for meaning in life, which was in turn associated with political extremism. The authors suggest that adopting a more extreme political ideology is one way that people re-inject meaningfulness into a boring situation.“These studies indicate that political views are, in part, based on boredom and the need to counteract these negative, existential experiences with ideologies that seem to provide meaning in life,” noted Dr Eric Igou from University of Limerick. The implications of these findings are obvious. “Possibly politically radicalised individuals and groups are, at least to some degree, driven by boredom experiences in their everyday lives as an attempt to make life seem more meaningful,” the authors pointed out.last_img read more

Life is a Circus

first_imgThrough lyrical metaphors inspired by the circus and everything extraordinary and unusual that surrounds its characters, Poonam comments on life while juxtaposing the mundane with wonder.She plays with textures and whimsical washes, layering hues with a weightlessness of touch and mood; her strokes sometimes applied with haste, sometimes with gentle attention. A monotone palette with intuitively enfolding depth of tone reveals the commingling of light and shade. Also Read – Add new books to your shelfJubilation exudes from the body language of one character, an acrobat delighted at union with her lover, flying through space and time. The everyday melancholia of life flashes mildly in the expression of another. A poised fire-eater devours flames of light, unabashed by her confidence and glory.These artworks allow you to enter another realm, a parallel universe you discover almost by accident, like finding an old photograph of yourself tucked away in a book. Wrought with nostalgia and details that resonate old world charm, Poonam captures forgotten emotions. The style and content of her painting hold a universal appeal in today’s chaotic world with hues of muted colours. While gazing at the archetypes painted by Poonam, unknowingly, the paradigm shifts, and you find yourself looking back at you. Her characters invite you to discover, wonder and seek joy as you once did in a wondrous thing like the circus – or is it life?last_img read more