📰 Swanky terminal for Kartarpur pilgrims
Land acquisition starts for the facility that will come up on 50 acres of land
•The Centre has approved a state-of-the-art passenger terminal building, spread over 50 acres and estimated at Rs. 190 crore, for the Kartarpur Corridor, a senior official of the Union Home Ministry said.
•A 300-foot-high flagpole, bearing the tricolour, will also be erected at the International Border, the official said.
•The passenger terminal building complex will have all amenities for pilgrims visiting the Kartarpur Sahib Gurdwara across the border in Pakistan. The approval came after the Cabinet decided last November to develop the Kartarpur Corridor from Dera Baba Nanak in Gurdaspur district of Punjab to the International Border.
•The Land Ports Authority of India (LPAI), mandated to build and operate integrated checkpoints along the land borders, has reportedly been entrusted with this task. It has been directed to complete the work before the 550th birth anniversary of Guru Nanak Dev in November this year.
•Fifty acres of land has been identified, and will be developed in two phases. “Phase I will be developed over 15 acres, and land acquisition has already started,” another official said. The complex, to be developed in the first phase, will be fully air-conditioned, with a built-up area of roughly 21,650 square metres.
•The design of the complex has been inspired by the symbol ‘Khanda,’ which represents the values of oneness and humanity, he said.
Disabled-friendly design
•The disabled-friendly building will display murals and photographs based on Indian cultural values, with eye-soothing landscaping.
•It will have adequate immigration and customs clearance facilities to ensure smooth movement of 5,000 pilgrims a day, the official said. The complex will have kiosks, cloakrooms and parking lots.
•In Phase II, a visitors’ gallery, a hospital, accommodation for pilgrims and more amenities will be created.
What does it mean?
•An ‘Official Secrets Act’ is a generic term that is used to refer to a law — originally invented by the British, and then exported across the Commonwealth — that is designed to keep certain kinds of information confidential, including, but not always limited to, information involving the affairs of state, diplomacy, national security, espionage and other state secrets. Across multiple countries, the Official Secrets Acts follow a similar pattern: classifying certain categories of information as “official secrets,” and then providing stiff penalties for any sharing, dissemination or publication of such information.
What are its traits?
•India’s Official Secrets Act (OSA) dates back to 1923, unsurprisingly a creation of the colonial regime. The 1923 Act includes penalties for spying (which, in turn, includes even “approaching” or being “in the vicinity of” a prohibited place, publishing any “sketch” or “plan” that might be useful to the enemy, with a prejudicial purpose.) Additionally, however, it punishes the communication of any information obtained in contravention of the Act, which could prejudice the security of the state, or friendly relations with foreign states. Furthermore, it punished people who knowingly receive such information — a provision clearly designed to capture investigative journalism.
What is the criticism?
•The primary critique of the Act is that it flips the constitutive logic of a democratic republic, where the state is supposed to be transparent to its citizens. While it is nobody’s case that all information ought to be made public – for example, troop movements in wartime or confidential trade negotiation positions, to take two examples, obviously need to be secret – there should be a heavy presumption against secrecy. Under the OSA, however, the state is given wide powers to place information off-limits to citizens, simply by stipulating that certain documents are secret — and then draconian powers to punish them in case it is made public, regardless of the public interest involved. This makes whistle-blowing and investigative journalism a perilous enterprise, no matter how critically important it might be to have the information public.
But what about the RTI?
•The scope of the OSA has been somewhat diluted, thanks to the Right to Information Act. Section 22 of the RTI Act expressly says it overrides the OSA. In other words, it is not open to the government to deny access to a document demanded through an RTI question, on the basis that it has been marked secret under the OSA. Rather, the government will have to justify its decision to withhold information under the arguably narrower exception clauses of the RTI Act itself.
How often isit used?
•The OSA is not used very often, but it is used enough times to keep it in the news, and to exercise a chilling effect (especially on investigative journalism). Recent, high-profile cases involving the OSA include that of the journalist Iftikhar Gilani (the case was withdrawn), the diplomat Madhuri Gupta (who was convicted of espionage charges), and the scientist Nambi Narayanan (who was charged, tried, and acquitted of espionage charges — and later directed to be paid compensation by the Supreme Court).
What is its future?
•As recently as 2006, the Home Ministry recommended substantial changes to the OSA, in line with the privacy regime established by the RTI. From time to time, there are calls to repeal the OSA and replace it with a National Security Act that is more consistent with the aspirations of an open, democratic republic. However, the OSA has proved resilient, and it would be reasonable to assume that we are stuck with it for at least the medium-term future.
📰 Why is GSP vital to India-U.S. trade ties?
What is the programme?
•The Generalized System of Preferences is the largest and oldest United States trade preference programme. The U.S. intended it to promote economic development by eliminating duties on some products it imports from the 120 countries designated as beneficiaries.
When was it introduced?
•It was established by the Trade Act of 1974. According to the website of the U.S. Trade Representative, the GSP helps spur sustainable development in beneficiary countries by helping them increase and diversify their trade with the U.S. The U.S. also believes that moving GSP imports from the docks to U.S. consumers, farmers, and manufacturers supports tens of thousands of jobs in the U.S. The other benefit is that “GSP boosts American competitiveness by reducing the costs of imported inputs used by U.S. companies to manufacture goods in the United States.” The Trade Representative says the GSP is important to U.S. small businesses, many of which rely on the programmes’ duty savings to stay competitive.
Why is it important for India?
•The Indian export industry may not feel the pinch of the GSP removal for India by the U.S. The loss for the industry amounts to about $190 million on exports of $5.6 billion falling under the GSP category. But specific sectors, such as gem and jewellery, leather and processed foods will lose the benefits of the programme. A producer may be able to bear 2-3% of the loss from the change, but not more. The loss, in export of some kinds of rice for example, may even exceed 10%. The landed price of goods from India has to be the same as it was before the GSP was removed. If not, consumers of those products in the U.S. would gravitate to producers that enjoy the GSP benefits and hence are able to offer lower prices. Obviously, it is difficult to get back a customer that a competitor takes away.
Why is India in the cross-hairs?
•The U.S. conducts periodic reviews of the programme. The review for India, taken up last year, focussed on ‘whether it is meeting the eligibility criterion that requires a GSP beneficiary country to assure the U.S. that it will provide equitable and reasonable access to its market.’ The Trade Representative accepted two petitions asserting that India did not meet the criterion: one from the National Milk Producers Federation and the U.S. Dairy Export Council, and the other from the Advanced Medical Technology Association. India wants dairy products, which could form part of religious worship, certified that they were was only derived from animals that have not been fed food containing internal organs. Other exporters such as EU nations and New Zealand certify their products, but the U.S. has so far not done so. Second, India has recently placed a cap on the prices of medical devices, like stents, that impacts U.S. exports of such devices.
What can the Indian government do?
•The government must offer fiscal help to the affected sectors. But the obvious question is: what can India do if it has to be compliant with World Trade Organisation rules that protect all its members equally from undue sops given to exporters? A wry answer is that if the U.S. is not playing by WTO rules, other countries too need to be able to protect their industries. But it is possible to offer some breather to producers suffering losses from the GSP removal, even while being WTO-compliant. The Centre could consider refund of taxes for goods not under GST. Use of electricity or petrol in the manufacture of such goods but for which an input credit is not available could qualify here. Helping such sectors would also protect jobs; especially when job creation is at a low.
📰 No campaigning with defence staff posters: EC
•Taking cognisance of a political banner bearing Wing Commander Abhinandan Varthaman’s portrait along with the photographs of Prime Minister Narendra Modi, BJP president Amit Shah and others, the Election Commission on Saturday said “strictest action” would be taken in such cases once the model code of conduct was in place.
•After a picture of the banner was brought to the notice of the Commission, spokesperson Sheyphali Sharan said: “ECI already has instructions issued on such matters. Once the model code of conduct comes into force, the ECI will take strictest action in such cases, if the instructions are violated.” The code comes into effect once the election schedule is announced.
•In a letter to the recognised parties issued later on Saturday, the ECI said it had been brought to its notice that some political parties were using the photographs of defence personnel in advertisements as part of their political campaigning.
•Asking the parties to issue appropriate instructions to their candidates, leaders and cadres to ensure strict compliance, the ECI cited a general advisory dated December 4, 2013, in this regard. The advisory called upon political parties to desist from displaying photos of defence personnel as part of their election propaganda.
📰 Nirav extradition to start soon: ED
Request referred to U.K. court, says agency; no information on case, says MEA
•Extradition proceedings against diamond merchant Nirav Modi, main accused in the Rs. 13,578 crore Punjab National Bank fraud, may be initiated soon, as the United Kingdom’s Home Office has referred India’s request to the Westminster Magistrate Court, the Enforcement Directorate said on Saturday.
•“The U.K. Home Office has confirmed that the extradition request has been certified by the Home Secretary and the same has been sent to the Westminster Magistrate Court District Judge for further proceedings,” the agency said.
•However, the Ministry of External Affairs (MEA) did not have any information about the case going to court. MEA spokesperson Raveesh Kumar said: “We had made a request for extradition to the U.K., based on information from the CBI and the ED in August last year. Despite all that we have seen on television today, the status [of the request] remains the same. The U.K. is still to respond and still considering our request... ”
•“The fact that we asked for his extradition from the U.K. itself means that we are aware he is in the U.K. Just because he has been spotted there doesn’t mean he can be immediately brought back to India; there is a process,” Mr. Kumar said.
📰 Protecting the Sundarban wetlands
•On January 30, the Indian Sundarban was accorded the status of ‘Wetland of International Importance’ under the Ramsar Convention. The Sundarbans comprises hundreds of islands and a network of rivers, tributaries and creeks in the delta of the Ganga and the Brahmaputra at the mouth of the Bay of Bengal in India and Bangladesh. Located on the southwestern part of the delta, the Indian Sundarban constitutes over 60% of the country’s total mangrove forest area. It is the 27th Ramsar Site in India, and with an area of 4,23,000 hectares is now the largest protected wetland in the country.
Why is this important?
•The Convention on Wetlands of International Importance, better known as the Ramsar Convention, is an international agreement promoting the conservation and wise use of wetlands. It is the only global treaty to focus on a single ecosystem. The convention was adopted in the Iranian city of Ramsar in 1971 and came into force in 1975. Traditionally viewed as a wasteland or breeding ground of disease, wetlands actually provide freshwater and food, and serve as nature’s shock absorber. Wetlands, critical for biodiversity, are disappearing rapidly, with recent estimates showing that 64% or more of the world’s wetlands have vanished since 1900. Major changes in land use for agriculture and grazing, water diversion for dams and canals and infrastructure development are considered to be some of the main causes of loss and degradation of wetlands.
How did it qualify?
•The Indian Sundarban met four of the nine criteria required for the status of ‘Wetland of International Importance’ — presence of rare species and threatened ecological communities, biological diversity, significant and representative fish and fish spawning ground and migration path. The Indian Sundarban, also a UNESCO world heritage site, is home to the Royal Bengal Tiger. The Ramsar website points out that the Indian Sundarban is also home to a large number of “rare and globally threatened species, such as the critically endangered northern river terrapin (Batagur baska), the endangered Irrawaddy dolphin (Orcaella brevirostris), and the vulnerable fishing cat (Prionailurus viverrinus).” Two of the world’s four horseshoe crab species, and eight of India’s 12 species of kingfisher are also found here. Recent studies claim that the Indian Sundarban is home to 2,626 faunal species and 90% of the country’s mangrove varieties.
Will the status help?
•Environmentalists and forest officials say the Ramsar status will help to highlight conservation issues of the Sundarbans at the international level. The part of the Sundarban delta, which lies in Bangladesh, was accorded the status of a Ramsar site in 1992, and with Indian Sundarban getting it too, international cooperation between the two countries for the protection of this unique ecosystem will increase. This could lead to a better conservation strategy for flagship species such as the tiger and the northern river terrapin.
What are the threats?
•While the Indian Sundarban is a biodiverse preserve, over four million people live on its northern and northwestern periphery, putting pressure on the ecosystem. Concerns have been raised about natural ecosystems being changed for cultivation of shrimp, crab, molluscs and fish.
•The Ramsar Information Sheet lists fishing and harvesting of aquatic resources as a “high impact” actual threat to the wetland. The other threats are from dredging, oil and gas drilling, logging and wood harvesting, hunting and collecting terrestrial animals. Salinity has been categorised as a medium and tourism as a low impact actual threat in the region. Experts believe that while the Ramsar status may bring in international recognition to the Indian Sundarban, the wetland, which along with anthropogenic pressures, is also vulnerable to climate change and requires better management and conservation practices.
📰 Relaxation of rules to aid red-flagged Andamans tourism project
The Aves Island project had not received clearance from an expert panel in February as it failed to satisfy the coastal zone regulations
•The Environment Ministry has amended laws that now allow a proposed tourism project in the Aves Island, of the Andaman and Nicobar island (A&N) territory, to come up.
•The project was the only one of three high-profile proposed tourism projects that did not get a clearance from an expert committee on coastal clearance in February. This was because the proposed Aves Island project was located 20 m away from the High Tide Line(HTL) and existing rules required such projects to be at least 50 m away.
•An official said that while the new rules did ease the way for the Aves Island project, it was also done to broadly align the changes in coastal zone regulations in the country’s mainland States with the island regions. “What is important is that there is no other industrial development in the A&N, and tourism is a major thrust area that we have to consider. However, there continue to be stringent provisions on how infrastructure and development projects can be executed,” an official, who did not want to be identified, told The Hindu . These were “high end” eco tourism projects and had to strictly adhere to the island management plan, the official added.
•In December, the government had issued a coastal regulation zone notification that largely allows tourism and development projects located near coasts in mainland States to come up closer to the sea. It also issued an Island Zone Protection Notification in January 2019 to allow similar relaxations in the A&N Islands.
Deferred clearance
•In January, an expert committee of the Union Environment Ministry “deferred” clearance to a Rs. 100 crore proposal by the Andaman and Nicobar Islands Integrated Development Corporation Limited to develop an island resort, as well as put up “premium tents” and “tree houses,” on the grounds that it did not account for the biodiversity of the islands’ coast.
•After site visits, the committee in February recommended two of them— at Lalaji Bay on Long Island and at Smith Island — for island protection zone clearance, with caveats. However, the Aves Island project was still red-flagged primarily because of the 50 m clause. In light of the March 8th notification, the committee is likely to re-look at the project.
📰 A smart indicator to boost frozen food safety
Gold-based nanoparticlescan highlight temperature abuse
•The temperature at which food products are stored is vital in ensuring their quality. For example, in retail outlets across India, power failure and repeated opening and closing of freezer storage units in which food products are stored can lead to temperature fluctuations. These in turn can affect the quality of food, especially perishable food, leading to microbial growth. Temperature fluctuations can also affect vaccines and drugs that are stored in cold storage or at below room temperature.
•Researchers from the Indian Council of Agricultural Research-Central Institute of Fisheries Technology (ICAR-CIFT), Kochi, Kerala, in collaboration with the University of Wisconsin, Madison, U.S., have now found a way using gold nanoparticles that they synthesised to help tell if frozen food is still edible.
How it works
•The nanoparticles change colour in response to changes in temperature. They become ruby red (similar to the colour of red wine) at -18° C and turn purple when the temperature rises. At room temperature, their colour is dark grey.
•To synthesise the nanoparticles, the researchers used chitosan, a natural biodegradable polysaccharide that was extracted from marine waste such as shrimp and crab shell. A solution of chitosan and gold chloride solution was heated for about 30 minutes at 90° C. Though the sample preparation process was simple, care was taken to maintain proper conditions such as temperature, stirring and base concentration of the gold solution.
•The nanoparticles remained stable when tested at -18° C. Their colour and other physical properties remained intact even at the end of 30 days of testing at -18° C.
•Explains Dr. C.O. Mohan, Senior Scientist, ICAR-CIFT, Kochi and corresponding author of the work that has been published in npj Science of Food , “The colour change of the nanoparticles is irreversible. So once they change from red to purple or grey when the temperature increases, the original colour cannot be regained even if the temperature is brought back to -18° C.” He adds, “They can be attached to the outer surface of the food or pharmaceutical packs as a visible indicator without coming in contact with the product.”
Looking ahead
•According to him, such smart indicators can be made using a very small quantity of chitosan-gold nanoparticle solution to identify frozen temperature abuse. It would cost less than Rs. 2 a pack. The team is also working to develop smart indicators from nanoparticles of other metals to further reduce the cost.
📰 IIT-H’s device detects heart attack early
Spots key cardiac biomarker even in very low concentrations, which can be a life-saver
•A low-cost, ultra-sensitive device that is capable of detecting the cardiac biomarker troponin T protein has been fabricated by a research team from the Indian Institute of Technology (IIT) Hyderabad. Troponin T is a cardiac protein that is released into the bloodstream after a heart attack.
•Unlike the commercially available test that can detect the protein at nanogram per ml concentration, this device can detect the protein at an extremely low concentration of femto gram per ml. This could help pave the way for early diagnosis of a heart attack, increasing a patient’s survival rate. It even has the potential to be able to predict the onset of a heart attack.
Cost-effective fabrication
•Unlike electrodes that are available, it costs very little to fabricate this bioelectrode. This is because a commercially available substrate was used. Further, very little antibody was needed to coat the electrode.
•The electrode was fabricated by depositing perovskite (zinc tin oxide) material electrochemically onto the substrate (indium tin oxide coated polyethylene terephthalate). Glassy carbon electrode coated with the same perovskite material was then used as a control. Perovskite increases the volume-to-surface area of the electrode, thereby increasing its sensitivity.
•The electrodes coated with perovskite were then functionalised to attract proteins. To increase the specificity of the electrode to bind only to the troponin T protein, the electrodes were decorated or coated with the troponin T antibody.
Test findings
•The researchers added various concentrations of the biomarker (ranging from 1 femtogram per ml to 1 microgram per ml) to a buffer solution and measured the impedance (effective resistance in alternating current). Says Prof. Shiv Govind Singh from the Department of Electrical Engineering and corresponding author of a paper published in the journal Analytical Methods , “Compared with the current limit of detection, the bioelectrode was able to detect troponin T even when it is 10,000 times less in concentration.”
•When the troponin antigen binds to the antibody present on the electrode, the impedance increases. Adds Prof. Singh, “As more and more biomarker binds to the antibody, there is increased impedance, which is what we measure.” After some time, the electrode is saturated with the troponin protein, so no change in impedance is seen.
•The researchers measured impedance using different concentrations of the protein. They plan to use these impedance values to know the concentration of the protein when testing actual blood samples. Says Prof. Singh, “We can measure the impedance in real time. And by using a machine learning algorithm, we can measure the concentration of the biomarker in the sample.”
•To test the selectivity of the bioelectrode to bind to the biomarker, the researchers tested it on bovine serum albumin (BSA) and human serum albumin (HSA).
•Says Patta Supraja from the Department of Electrical Engineering at IIT Hyderabad and first author of the paper, “Only a slight change in relative resistance was observed in the case of HSA and BSA as only a small amount of proteins [from HSA and BSA] bind to the bioelectrode. This is unlike troponin where more protein gets bound to the bioelectrode, leading to more impedance.”
•She adds, “We then tested for interference by mixing the same amount of biomarker with either BSA or HSA. The sensor’s response was not adversely affected by either BSA or HSA.” The bioelectrode also showed consistent values when measurements were taken repeatedly using the same concentration of the biomarker.
Focus on miniaturisation
•The team is now working on how to miniaturise the readout instrument. Says Prof. Singh, “We will soon be able to capture the signal using a circuit the size of a chip. This will be connected to [a] mobile phone with an app that has a machine learning algorithm for quantification of the troponin biomarker.” He adds, “We will have the prototype ready in six months to one year.”
📰 Belle II: Chasing cousinly rivalry at the subatomic level
The experiment also looks for differences in the physics of muons, electron and tau particles
•Belle II, a particle accelerator experiment located in Tsukuba, Japan, is a unique facility in the world. Here, electrons and positrons (anti-electrons) collide to produce B mesons in order to study the breakdown of symmetry in these decays. As an international collaboration involving 26 countries, Belle II has an Indian link -- a team led by physicists and engineers from the Tata Institute of Fundamental Research, Mumbai, have built the fourth layer of the vertex detector.
•The focus at Belle II is on B-mesons — particles that contain the B-quark, also known as the beauty or bottom quark. Says Tom Browder from the University of Hawaii who is also the spokesperson for Belle II, “In particular, we focus on the differences between the decay of the B-mesons and that of their antiparticles, the anti B-mesons. We are looking for the breakdown in the symmetry between matter and antimatter.”
•This broken symmetry between matter and antimatter is one of the most fundamental questions in particle physics.
Asymmetric universe
•At the time of the Big Bang some 13.7 billion years ago, the universe was in a fully symmetric state with equal quantities of matter and antimatter. Yet, today, we are in this extremely antisymmetric state. The question is how did we get here? One of the first theoretical ideas about this was posed by Andrei Sakharov. Says Dr. Browder, “As soon as the first differences were discovered in particle physics between kaons and antikaons in 1964 at Brookhaven, Sakharov realised this was an important clue to understanding this asymmetry between matter and antimatter.” Sakharov suggested that we start with this symmetric state of the universe at the beginning, then decays of elementary particles that were asymmetric between particles and antiparticles amplified this difference. That led to the matter-dominated universe.
•The original CP violation, or asymmetry between matter and antimatter, which was discovered in 1964, was found in Kaons — particles containing the strange quark. The effects there were tiny — about one part in a thousand.
•Dr. Browder explains, “For the particles containing the B quark, the effects of this matter-antimatter symmetry are large; they are of order 100%. The B quarks have much greater asymmetry. They are theoretically much easier to understand they are cleaner. That’s also the motivation for these machines.”
•In addition to other experiments at CERN, the European Organisation for Nuclear Research, there’s one experiment that is devoted to B quark physics — the LHCb or the Large Hadron Collider beauty experiment. In this, two proton beams are collided at high energies and the results are observed.
•Says Dr. Browder, “The facility in Japan uses electron-positron collisions. These are much cleaner, as the electron and positron are point-like particles. So, we will be in a competition with the LHCb as time proceeds.” He adds laughingly, “At the LHCb, they throw two Swiss watches at each other and [a] lot of stuff comes out, while we have clean collisions of point-like particles.”
Anomalous interactions
•In the Standard Model – the core theory of particle physics – there are generations of low mass particles (leptons); electrons, the muon and the relatively heavy cousin of the electron, the tau are the leptons. These particles are expected to have identical interaction strengths, the so-called couplings, in the Standard Model of weak interactions in physics. However, in particle decays where only leptons are produced (leptonic decays), it appears that the tau and muon particles have identical couplings. Specifically, interactions where a kaon particle decays to muon and a kaon decays to electron seem to have the same coupling to 1%. But B decays to tau leptons when compared to B decays to muon or electron are not on equal footing.
•“There is a hint of an anomaly there at 4 standard deviation,” says Dr. Browder, excitedly. However, he adds a word of caution: “We’d like to get much more data to see whether this is a fluctuation or whether we can pin this down and declare we have found new physics!”
•There is a similar thing in the B quark to S quark decay: The so-called Penguin decays. “If any one of this can be established, it would be fairly new physics,” he adds, mentioning that the Chennai group led by Rahul Sinha of The Institute of Mathematical Sciences works on the angular correlation in these decays.
📰 Pushing the purple frog to the edge
Human activities could pose a threat to its specialised breeding biology
•The rare and endangered soil-dwelling purple frog ( Nasikabatrachus sahyadrensis) begins its life as a tadpole in certain fast-flowing streams of the Western Ghats. Scientists have now found that the speed with which water flows down these streams is one of the main factors that determine the presence and aggregation of these tadpoles.
•The tadpoles are rheophilic, which means they thrive in running water. Apart from several other body adaptations, their specialised mouthparts, which are like suckers, help them to anchor onto rocky areas in flowing water for nearly 100 days. So what are the characteristics of a stream that help the tadpoles survive?
Behavioural insights
•To find out, researchers at the University of Delhi and the Kerala Forest Research Institute quantified four stream characteristics: water flow velocity; angle of the rocky base; water depth, and water temperature. The study, in Kerala, was restricted to 68 grids placed along 100 m in two streams at Kulamaav in Idukki district, an area the team already knew was home to the purple frog.
•Their results, published in the Journal of Asia-Pacific Biodiversity , show that the team spotted 550 tadpoles in these grids. Though found throughout the streams, the tadpoles tended to gather in large numbers only in areas with relatively higher water flow velocity. They also preferred steep, rocky slopes (65°-90° incline) and a water depth of 2-3 cm.
•The team made observations on tadpole behaviour and distribution too. The tadpoles were always active, moving even when they were attached to the rocky portions of the streams to feed on algae growing on rocks. The moment they sensed danger, they ‘escaped by immediately relaxing their hold on the rock, a behaviour that let them drift some distance downstream before re-attaching themselves to the substrate. Tadpoles in earlier stages of development stayed mostly in relatively slow-flowing portions of the stream’, while older tadpoles were found in faster currents.
Specific threats
•According to the authors, these findings and observations provide “a strong rationale linking the impact of dam construction to loss of tadpole habitat”. Ashish Thomas, lead author of the study, says the construction of dams and check dams, and levelling and narrowing of streams to expand plantations can alter stream characteristics, in turn affecting the survival of the purple frog tadpole. The damming effect can also slow down the streams feeding water to the river.
•He adds, “We hope to now study tadpoles in such modified streams and natural ones to understand this better.”
📰 NPL’s device produces high-quality, single-layer graphene
The quality of the single-layer graphene produced is metrology-grade, and the device is ready for technology transfer
•Researchers at Delhi’s National Physical Laboratory (CSIR-NPL) have designed a low-pressure chemical vapour deposition (LPCVD) device that allows high quality, single-layer graphene measuring 4 inches in length and 2 inches in width to be grown. The quality of the single-layer graphene is metrology-grade, and can be used in next-generation quantum devices.
•The thickness of a single layer is 0.34 nanometre and average grain size of graphene is 1-3 micrometre. Though there are about one billion grains in 4x2 square-inch single-layer graphene, the grains are highly connected to give a single continuous layer of graphene.
Cost-effective
•The LPCVD device developed indigenously costs about Rs.5,00,000, which is one-tenth of the imported ones. More importantly, the quality of the single-layer graphene grown using this device is superior than the ones reported in the literature. By growing single-layer graphene of high quality repeatedly for up to 30 times, the team led by Dr. Bipin Kumar Gupta from the Advanced Materials and Devices Metrology Division at NPL has demonstrated reproducibility. Results of the study were published in ACS Omega.
•“It is possible to grow single-layer graphene measuring 6x4 square-inches but the quality will not be as good as when we grow graphene of smaller dimensions,” says Dr. Gupta. This is because when attempts are made to grow larger graphene single layers, it is difficult to control the diffusion of carbon atoms which get deposited on the copper substrate. This compromises the quality of graphene single layer produced.
•“We completed the development of the device and are ready to transfer the technology,” says Dr. Gupta. “Already a few research institutions in India have shown interest.” In fact, single-layer graphene grown by Dr. Gupta’s team has been used for a specific study for quantum hall resistance metrology at Tata Institute of Fundamental Research (TIFR) in Mumbai and the results of the work have been analysed for further communication in scientific journal.
•Generally, LPCVD devices have three mass flow meters through which hydrogen, argon and hydrocarbon gases are supplied to grow the graphene. Since the mass flow meters are expensive, Dr. Gupta’s team replaced two such meters that supply argon and hydrocarbon with calibrated rotameters. “Unlike hydrogen, both argon and hydrocarbon have higher molecular weight and so it is easy to control the flow these gases. So we used calibrated rotameters as gas flow meters for these two gases,” he says. The expensive mass flow meter is used only for hydrogen.
•The graphene was grown on a substrate made of copper, which acts as a catalyst.
