“A typical photon detector, like a CCD or photo-multiplier tube, absorbs photons,” Johnson said. “These detectors don’t work for microwaves because the energy of a microwave photon is too small to generate charges. However, with a setup similar to the one used in our paper, one could measure the photon state by transferring the photon energy into the qubit. This method would destroy exactly one photon every time. In contrast, our detector does not transfer any energy. Instead, we attempt to add energy to the qubit from an external source in such a way that the success or failure of these attempts reveals information about the cavity state. You might worry that this added energy might leak into the cavity and changed the photon number, but we have checked that this does not, in fact, happen.”Achieving QND measurements of photons, while challenging, could be very useful for the development of quantum information technologies, which require complete control of quantum measurements. As the physicists note in their study, recent progress in manipulating microwave photons in superconducting circuits has increased the demand for a QND detector that operates in the gigahertz frequency range (like the one demonstrated here). In addition, the physicists predict that further research could make it possible to observe quantum jumps of light in a circuit, among other things.“QND detection in general is interesting because it is the only way that quantum mechanics allows to extract information from a system without modifying its state, and then allowing feedback and manipulation of the same,” Johnson said. “The applications are interesting because if one could implement feedback of a quantum system, one could imagine using these systems for quantum simulation and quantum computation, harnessing quantum mechanics toward the goal of practical application.” Yale scientists bring quantum optics to a microchip The physicists performed a quantum non-demolition measurement, illustrated in this circuit schematic, that could detect single photons without destroying them. The technique allows repeated measurements to be made that give the same result. Image credit: B.R. Johnson, et al. ©2010 Macmillan Publishers Limited. (PhysOrg.com) — In a way, the quantum world seems to know when it’s being watched. When physicists make measurements on photons and other quantum-scale particles, the measurements always disturb the system in some way. Although an ideal disturbance should still enable physicists to make multiple measurements and get the same result twice, most real measurements cause a greater disturbance than this ideal minimum, and prohibit physicists from making repeated measurements. In a recent study, physicists have demonstrated a new way to make one of the ideal measurements – called quantum non-demolition (QND) measurements – allowing physicists to detect single particles repeatedly without destroying them. The concept of QND measurements has been around since the beginning of quantum mechanics, and physicists have demonstrated different QND measurement techniques since the ‘70s. In the latest technique, developed by a team of physicists from Yale University, Princeton University, and the University of Waterloo, the scientists have shown how to measure the number of photons inside a microwave cavity in a way that preserves the photon state 90% of the time; in other words, the method is 90% QND. The physicists explain that, unlike previously reported QND methods, the new technique is strongly selective to chosen photon number states, which could make it useful for applications such as monitoring the state of a photon-based memory in a quantum computer.In their experiments, the physicists wanted to find out how many photons were in a microwave cavity. To do this without disturbing the system, they coupled a superconducting qubit to a cavity. This cavity stored the photons long enough for them to be measured – or “interrogated” – by using a set of controlled-NOT (CNOT) operations to encode information about the cavity state onto the qubit state. Then the qubit and storage cavity were decoupled, and the qubit state was read out. Because the qubit state now depends on the number of photons in the cavity, measuring the qubit reveals the number of photons.“Our method takes advantage of the ability to engineer interactions between cavities and qubits in superconducting circuits to make the qubit energies strongly depend on the number of photons in the cavity,” coauthor Blake Johnson of Yale University told PhysOrg.com. “We have made this effect large enough to build a new qubit-photon logic gate which allows us to perform conditional qubit operations based on the cavity state. This type of logic gate is not only applicable to photon readout, but also to some proposals for engineering interactions between photons by using a qubit as a mediator.”In the new design, the photon read out time is faster than the photon decay time. This timing difference allows the physicists to measure any qubit state several times during the lifetime of photons in the storage cavity. A single interrogation process takes about 550 nanoseconds, which includes the 50-nanosecond to initialize the qubit state. As expected with a high-quality QND method, the results of repeated interrogations are essentially indistinguishable from the first. In contrast, as Johnson explained, a typical quantum measurement would destroy one photon every time, so that repeated interrogations would give different results. Citation: Quantum non-demolition measurement allows physicists to count photons without destroying them (2010, July 9) retrieved 18 August 2019 from https://phys.org/news/2010-07-quantum-non-demolition-physicists-photons.html Copyright 2010 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Explore further More information: B.R. Johnson, et al. “Quantum non-demolition detection of single microwave photons in a circuit.” Nature Physics. Advance Online Publication. DOI:10.1038/NPHYS1710 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.
Structural characterization of single π-extended triangulene synthesized on Cu(111) and Au(111) surfaces. (A and D) Large-scale STM images of triangulene molecules (A) on Cu(111) and (D) on Au(111) [(A) Vs = −1 V and I = 1 nA; scale bar, 5 nm; (D) Vs = 1 V and I = 0.2 nA; scale bar, 1.5 nm]. (B and E) Zoom-in STM images of a single triangulene (B) on Cu(111) and (E) on Au(111) [(B) Vs = −0.8 V and I = 1 nA; (E) Vs = −0.8 V and I = 1 nA; scale bar, 4 Å]. (C and F) nc-AFM images of a single triangulene (C) on Cu(111) and (F) on Au(111) acquired using a CO-functionalized tip [(C) ∆z = 0.15 Å, Vs = 30 mV, I = 0.3 nA; (F) ∆z = 0.15 Å, Vs = 10 mV, I = 0.5 nA; scale bar, 4 Å]. fcc, face-centered cubic; hcp, hexagonal close-packed. Credit: Science Advances, doi: 10.1126/sciadv.aav7717. In this way, Jie Su and colleagues demonstrated a feasible bottom-up approach to synthesize atomically precise unsubstituted triangulene on metallic surfaces. They used nc-AFM imaging to ambiguously confirm the zigzag edge topology of the molecule and used STM measurements to resolve the edge localized electronic states. The successful synthesis of π-extended triangulenes will allow scientists to investigate magnetism and spin transport properties at the level of the single-molecule. The scientists envision that the synthetic process will open a new avenue to engineer larger, triangular zigzag edged graphene quantum dots with atomic precision for spin and quantum transport applications. It is therefore of great interest to continue generating similar systems with diverse sizes and spin numbers to uncover their properties on a variety of substrates using spin-polarized STM studies. More information: Jie Su et al. Atomically precise bottom-up synthesis of π-extended triangulene, Science Advances (2019). DOI: 10.1126/sciadv.aav7717 Manuel Melle-Franco. When 1 + 1 is odd, Nature Nanotechnology (2017). DOI: 10.1038/nnano.2017.9 Yasushi Morita et al. Synthetic organic spin chemistry for structurally well-defined open-shell graphene fragments, Nature Chemistry (2011). DOI: 10.1038/nchem.985 Pascal Ruffieux et al. On-surface synthesis of graphene nanoribbons with zigzag edge topology, Nature (2016). DOI: 10.1038/nature17151 Journal information: Science Advances To gain further insights into the triangulene electronic structure, Su et al. performed spin-polarized density functional theory (DFT) calculations. The energy ordering of these electron states were consistent with previous calculations of similar graphene molecular systems. Additionally, the calculations also revealed a total magnetic moment of 3.58 μb for triangulene on the Au substrate, suggesting that its magnetic ground state could be retained on the Au (111) surface. The DFT (density functional theory) provided reliable information on the ground-state energy ordering and spatial shape of molecular orbitals. Su et al. observed the frontier molecular orbitals (highest-energy occupied and lowest-energy unoccupied molecular orbitals) to contain four pairs of orbitals with corresponding wave function plots. Su et al also used the GW method of many-body perturbation to calculate the quasiparticle energies of a free triangulene, where the quasiparticle gap was predicted to be 2.81 eV. They then experimentally determined the energy gap of Au-supported triangulene to be ~1.7 eV consistent with previous studies of GNRs and other molecular systems of comparable size. All observations indicated a magnetic ground state of triangulene on Au (111), which the scientists also validated with the DFT calculations. In a recent report on Science Advances, Jie Su and colleagues at the interdisciplinary departments of chemistry, advanced 2-D materials, physics and engineering developed bottom-up synthesis of π-extended triangulene with atomic precision using surface-assisted cyclodehydrogenation of a molecular precursor on metallic surfaces. Using atomic force microscopy (AFM) measurements, Su et al. resolved the ZTGM-like skeleton containing 15 fused benzene rings. Then, using scanning tunneling spectroscopy (STM) measurements they revealed the edge-localized electronic states. Coupled with supporting density functional theory calculations, Su et al. showed that triangulenes synthesized on gold [Au (111)] retained an open-shell π-conjugated character with magnetic ground states.In synthetic organic chemistry, when triangular motifs are clipped along the zigzag orientation of graphene, scientists can create an entire family of zigzag-edged triangular graphene molecules. Such molecules are predicted to have multiple, unpaired π-electrons (Pi-electrons) and high-spin ground states with large net spin that scaled linearly with the number of carbon atoms of the zigzag edges. Scientists therefore consider ZTGMs as promising candidates for molecular spintronic devices. The direct chemical synthesis of unsubstituted ZTGMs is a long-standing challenge due to their high chemical instability. Researchers had recently adopted a tip-assisted approach to synthesize unsubstituted triangulene with detailed structural and electrical properties, but the method could only manipulate a single target molecule at a time. The strategy was therefore only useful for specific applications due to a lack of scalability. Su et al. used large-scale STM images to reveal well-separated triangle-shaped molecules after annealing to the precursor-decorated Cu (111) and Au (111) surfaces. They recorded the magnified STM images with a metallic tip to show that individual molecules adopted triangular/planar configurations on both substrates. At the edge of these molecules, the research team observed characteristic nodal features resembling the zigzag edges or termini of graphene nanoribbons (GNRs). When they conducted noncontact AFM (nc-AFM) measurements to accurately determine the chemistry of reaction products, the bright areas represented a high-frequency shift with higher electron density. As a result, they clearly resolved the zigzag-edged topology of 15 fused benzene rings, where the experimental results were in excellent agreement with those simulated using a numerical model in a previous study . The observed molecular morphology therefore corresponded to the expected triangulene.The freestanding triangulene contained four unpaired π-electrons as theoretically predicted. To unveil the peculiar electronic properties of the molecule, Su et al. performed scanning tunneling spectroscopy (STS) measurements of single triangulene grown on the weakly interacting Au (111) substrates using a metallic tip. To capture the spatial distribution of the observed electron states, the scientists completed differential conductance (dI/dV) mapping on a single triangulene molecule at different sample biases. On examination, the differential conductance map revealed five bright lobes located at the edge of the triangulene, represented by a characteristic nodal map. The observed characteristic feature was similar to the nodal pattern of spin-polarized electronic states seen with zigzag termini and zigzag edge of GNRs. Electronic structure of triangulene. (A to D) Experimental dI/dV maps recorded at different energy positions [−2.2 V for (A), −0.62 V for (B), 1.07 V for (C), and 2.2 V for (D); scale bar, 4 Å]. (E to H) Simulated dI/dV maps of triangulene acquired at different energy positions corresponding to different sets of orbitals: (E) ψ2↓ and ψ3↓, (F) ψ4↑ to ψ7↑, (G) ψ4↓ to ψ7↓ (note: the weight of ψ5↓ is set to 0.7; refer to fig. S8 for more details), and (H) ψ8↑ and ψ9↑. Scale bar, 4 Å. (I) Calculated spin-polarized molecular orbital energies of an isolated triangulene. Blue and red refers to spin-up and spin-down states, respectively. (J) DFT-calculated wave functions of four pairs of spin-polarized orbitals [ψ4 ↑ ( ↓ ), ψ5 ↑ ( ↓ ), ψ6 ↑ ( ↓ ), and ψ7 ↑ ( ↓ )]. Red and blue colors indicate the wave functions with positive or negative values, respectively. Credit: Science Advances, doi: 10.1126/sciadv.aav7717 Citation: Atomically precise bottom-up synthesis of π-extended  triangulene (2019, July 31) retrieved 18 August 2019 from https://phys.org/news/2019-07-atomically-precise-bottom-up-synthesis-extended.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
A full month of exciting and educative workshops celebrating heritage art forms from across India.Indulge in creating story-boxes from Rajasthan or bring to life mythical characters through workshops on leather puppets and shadow plays, from folk paintings to calligraphy and clay relief tiles, there’s a range to choose from.‘The idea behind conducting these workshops is to bring people closer to the wealth of folk art and craft forms existing in our country, to foster creativity and to spread not only awareness but appreciation, especially among the young people, for the richness of our cultural heritage. It is only when we attempt to learn these traditional arts from the master craftsmen themselves can we truly value the skills, hard work and imagination that goes into creating each piece. Besides, they are a lot of fun and a wonderful activity over the summer.’ says Nerupama Y Modwel, Director Intangible Cultural Heritage (ICH), INTACH. Also Read – ‘Playing Jojo was emotionally exhausting’Giving you a glimpse of India’s rich cultural heritage will be the master craftsmen/ tribal artists themselves visiting from Rajasthan, Gujarat, Karnataka, Orissa and Andhra Pradesh, etc.‘This is an excellent opportunity for people to engage with rural artists and exchange stories/myths/legends behind these arts. More than anything, you go back with the satisfaction of having learnt the skill of making something so unique and special- and one can actually hand-make gift items for loved ones following this experience,’ says Medhavi Gandhi, Director of Happy Hands Foundation.Open to children, parents, professionals, art enthusiasts, culture junkies and curious minds – hurry and sign up for these incredible classes (registrations close 16 May). Check – Workshops Website: http://www.artpitara.wordpress.com?and Facebook: https://www.facebook.com/events/527993603989501/ for prices and classes.
Kolkata: Many Ayurvedic doctors from Bengal will join a huge sports event, a nationwide campaign in Madhya Pradesh, during which they will take part in a 400 meter race, high jump, long jump, tug of war, Kabbaddi and table tennis among other games.With an aim to empower the young generation in Ayurveda and improve the existing standards of the one of the oldest modes of treatment in the country, the National Ayurveda Students and Young Association (NASYA) has come up with this unique idea to organise a Also Read – Rain batters Kolkata, cripples normal lifesports event.Various principals or directors of all the Ayurveda Colleges across the country have been urged to take part in the event called Rashtriya Ayurveda Krida Mahotsav. It was learnt that there will be more than 3,500 participants. Around 3,000 Ayurvedic doctors from many states including Bengal will join the event that will be held at Tatya Tope Stadium in Madhya Pradesh from 27-29 September.Many Ayurvedic doctors and students from three under-graduate medical colleges in the state —Rajiv Gandhi Memorial Ayurvedic Medical College and Hospital, JB Roy State Ayurvedic Medical College and Hospital and Raghunath Ayurved Mahavidyalaya & Hospital, are expected to join the event. There will also be representation from the IPGAER & SVSP, the post graduate ayurvedic college. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedMinistry of AYUSH has written a letter to the management boards of Ayurveda Medical Colleges in the state urging them to motivate their students for attending the sports carnival.This will also help develop a strong network of Ayurveda fraternity. It was learnt that representatives from more than 200 Ayurvedic colleges are expected to take part in the programme.The event has been planned to create an opportunity for the youth of Ayurveda to exhibit their talents.”This is a unique initiative taken by the NASYA for stressing on the importance of being physically fit. It is extremely important to send the message that not only doctors but common people must also be health conscious and pick up the habit of exercising regularly,” Dr Sumit Sur, state president of NASYA said.
The Commercial office of Peru in India has been set up to further trade, investments, agriculture and tourism ties between India and Peru. The office has been tirelessly working towards spreading awareness about Peruvian culture amongst Indians through events and interactions.The National Geographic Traveller India and commercial office of Peru jointly hosted two events in Mumbai and New Delhi celebrating Peru and its rich food and cultural heritage. The events shone the spotlight on the attractiveness of Peru as a tourist destination, sharing stories about the country with a special audience. Those present were privy to presentations, discussions, food tastings and cultural experiences, aimed at creating a lasting impression of Peru. The first step in building awareness around a destination requires creating a buzz and these events were curated to do that. Also Read – Add new books to your shelfAt the Mumbai event, in addition to food tasting of Peruvian classics like ceviche and pisco sour, the audiences witnessed to a discussion about the country’s food history and culture. Held in the stylish Lima restaurant and bar by the Michelin Chef Atul Kochchar, the evening was a full house. The panelists included Luis Cabello, the economic and commercial counsellor for Peru in India, Priya Ganapathy, writer and guidebook author, and Ansoo Gupta, chief operating officer of Pinstorm, Founder of One Shoe Trust for Responsible and Mindful Travels. Also Read – Over 2 hours screen time daily will make your kids impulsiveThe New Delhi meet-up, held at the Cultural Gallery of the Embassy of Peru, celebrated the spectacular culture and heritage of Peru. The audiences were given a glimpse of the festivals, revelry and pageantry that are part of everyday life in Peru. The panelists included the Luis Cabello, who was joined by Ansoo Gupta, Mandip Singh Soin, founder of Ibex Expeditions, and Sumana Mukherjee, food and travel writer. The attendees at both events were a mix of high net worth individuals with a passion for discovering new places, travel and food bloggers.
Kolkata: Trinamool Congress supremo Mamata Banerjee said on Sunday that the country’s independence is at stake under the rule of Narendra Modi and in the same breath, urged the people of the nation to shun their narrow self-interests and vote to oust the saffron party in the ensuing Lok Sabha polls.”I am very optimistic about the people’s front. The country is in a volatile situation under the rule of BJP. I will urge all the people of the country not to be carried away by self-interest and vote for toppling the Narendra Modi government at the Centre,” Banerjee said at Kolkata Airport, while leaving for Visakhapatnam to attend a United India rally. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataAndhra Pradesh Chief Minister and Telegu Desam Party (TDP) chief N Chandrababu Naidu has invited Banerjee to address the rally. “They are trying to create fear psychosis among the people who have lost the right to express their independent opinion. An autocratic government is running at the Centre. The country’s democracy is at stake,” Banerjee asserted. She further slammed the Centre for taking over control of the investigating agencies, disinvestment in the public sector and pushing the farmers of the country into a disastrous situation. Also Read – Lightning kills 8, injures 16 in state”The Opposition should unite to oust the saffron party for saving the democracy of the country,” she reiterated. Banerjee will return to the city on Monday morning and will address an election meeting at Cooch Behar on April 4. She will campaign at Dhubri in Assam on April 5 and then will be speaking at 100 odd meetings in Bengal, in connection with the Lok Sabha polls. The state, which will be going to polls in seven phases, has 42 Lok Sabha seats. TMC has fielded candidates in nine out of 14 LS seats in Assam. It may be mentioned that it was Banerjee who had initiated the move to set up the United India front to oust Narendra Modi. On January 19, the historic United India rally was held in Kolkata, where leaders of 21 political parties took part. The rally was addressed by political veterans like Sharad Pawar, Farooq Abdullah, former Prime Minister H D Deve Gowda and Mallikarjun Kharge. There were youngsters like Akhilesh Yadav, Tejashwi Yadav and Hardik Patel in the rally as well. M K Stalin had also addressed the rally. She was the first political leader to criticise the note ban announced by the Prime Minister on November 8, 2016. Over the years, economists of both national and international acclaim have pointed out the disaster which had hit the Indian economy due to the decision of the Narendra Modi government. In the 2014 election BJP had bagged three seats in Andhra Pradesh, but experts feel that the party has a slim chance of retaining them in 2019.
Kolkata: West Bengal Chief Minister Mamata Banerjee on Monday slammed the central forces for allegedly firing “inside” a polling booth in Birbhum district and accused the BJP of misusing the forces in the elections. Stating that the law and order is a state subject, she said it is not the job of the central forces to enter polling booths and they should keep vigil outside. In Dubrajpur area of Birbhum constituency, voters allegedly engaged in a scuffle with the central forces when they were barred from entering booths with mobile phones, a senior election official said. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: Mamata Security personnel reportedly fire in the air to control the mob, following which polling was stalled in the booths, the official said. “I have heard that the CRPF fired inside a booth in Dubrajpur. I am yet to get the detailed report. CRPF personnel can be deputed outside booths, but they do not have the right to lathicharge or fire,” Banerjee, also the TMC supremo, said. She alleged that the firing was a ploy to rig the polls by the BJP with the help of central forces. Also Read – Lightning kills 8, injures 16 in state “Law and order is a state subject and not a central subject. Even if the central forces have to conduct a route march, they are required to do it along with the state police,” the TMC chief said while speaking at rallies in Bagdhah and Swaroop Nagar in North 24 Parganas district. Banerjee accused the BJP of misusing the law and bringing in central forces without depending on the state police and using them in garnering votes for themselves. “We know the law. I have heard that complaints were made (before the EC) that the central force personnel have gone inside booths and asked people to vote for the BJP. This will not help the BJP,” she said. “The BJP do not trust the Bengal police. The police are on security duty during the Durga Puja, during Diwali. They protect us from thieves and dacoits. And during elections, you need policemen from Delhi,” Banerjee said. Asking the BJP to trust the people, she said police will not vote for its candidates but the people will. Violence was reported from several parts of the eight Lok Sabha constituencies where polling is going on Monday. Clashes have broken out between the supporters of rival parties in Nanoor, Rampurhat, Nalhati and Siuri areas of Birbhum seat, injuring several people. The Election Commission has deployed central forces at around 98.8 per cent of the booths in the eight seats — Baharampur, Krishnagar, Ranaghat (SC), Burdwan East (SC), Burdwan-Durgapur, Asansol, Bolpur (SC) and Birbhum. Addressing the rallies, Banerjee called upon the people to vote against the BJP and dethrone Prime Minister Narendra Modi from power. “He (Modi) is adept at lying constantly,” Banerjee said adding “Whenever he comes to Bengal, he provokes his supporters to disrupt peace in the state in order to yield political dividend,” she alleged. The BJP brigade is distributing money to purchase voters and resorting to divisive politics which is in contrary to the state’s culture, Banerjee claimed. The TMC chief expressed confidence that her party will win all the 42 Lok Sabha seats in the state and play a pivotal role in forming the next government at the Centre.
Kolkata: The result of the first round of counselling of Joint Entrance Examination (JEE) students was announced by the West Bengal Joint Entrance Board on Wednesday. The successful candidates will have to present themselves between July 4 and 7 at 23 centres set up in Bengal and Agartala to verify their documents. The students can opt for the institutions where they have been allotted or can wait for the subsequent counselling round to upgrade their position.
Kolkata: The state government has decided to pull down the dangerous portion of Vivekananda Road flyover between Posta intersection and Ganesh Talkies.The decision was taken at a high-level meeting which was attended by the senior officials of Kolkata Metropolitan Development Authority (KMDA), Kolkata Municipal Corporation (KMC) and Kolkata Police. The officials have inspected the site. In three week’s time, the team will come up with a date when the stretch on the flyover, that has been termed “dangerous”, will be pulled down. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataThe team will have to consider various issues like whether the demolition work is going to affect the old buildings in the vicinity as many of them are more than a century old, if the residents of these buildings need to be evacuated then where are they going to be put up temporarily and so on. A 41-metre iron slab of the flyover fell on April 1, 2016. Twenty-six people died and 11 were injured in the incident. Chief Minister Mamata Banerjee had visited the site and supervised the debris cleaning operation herself. Also Read – Lightning kills 8, injures 16 in stateIn 2008, funds under the Jawaharlal Nehru National Urban Renewal Mission (JNNURM) was disbursed for the construction of the flyover, which started in 2009 during the Left Front regime. The estimated cost of the project was Rs 168 crore in 2008 when it was commissioned. Ashok Bhattacharya was the then Urban Development minister when the proposal was cleared in Delhi. When a portion of the flyover collapsed in 2016, around 75 percent of the construction of the bridge was completed. The construction of the flyover was mooted to ease Howrah-bound traffic movement from East Kolkata. From the very first day after the construction began, there had been movement to stop the process because of its faulty design. Development Employees Joint Action Committee had opposed its construction. After the construction of the flyover, it was found that many residents could not open the windows of their flats as the boundary wall of the structure was just two feet away from their buildings. But, the Left Front government refused to listen to their objection and finally went ahead with the project. As per the design of the flyover, the stretch on the road towards Howrah from the Vivekananda Road side was wider than the one coming from Howrah. Many engineers had also pointed out the faulty design.