Nothing will happen to me if justice is served in this false case: KhaledaBNP chairperson Khaleda Zia on Wednesday castigated those who had ordered filing of what she called a ‘fictitious graft case’ against her.Saying that she would be acquitted should justice prevail, the former prime minister observed that people who had filed this case would have been sued as well, had there been rule of law and an independent judiciary.”Nothing will happen to me if justice is served in this false case. Insha Allah (God willing), I will be acquitted,” Khaleda Zia told a press conference ahead of the verdict in Zia Orphanage Trust case to be delivered on Thursday.Read more: Your Khaleda didn’t commit any corruption: BNP chief tells countrymen”However, if the judgement is delivered to please the rulers, it will be a history of disgrace. The people of Bangladesh do not pardon the ones who commit such crimes,” the BNP leader said.A makeshift court is set to hand down the judgement in the case that implicated Khaleda, BNP senior vice chairman Tarique Rahman and four others.Khaleda mentioned that she was ready for any consequences in her fight to restore democracy and the peoples’ rights.”I am not scared of jail or any other punitive measures. I will not bow down to acts of intimidation,” she added.She further expressed her confidence that the rulers would not be successful in its ‘blueprint’ to keep her and her party from the elections by using the court.Khaleda argued that her lawyers had proved in the court that the plaintiff prepared concocted evidences to implicate her in the false case. She claimed that neither she had been involved with the Zia Orphanage Trust nor a single penny had been embezzled from its funds.”There is no justice in the country,” she said, terming the incumbents who were rampantly saying that she ‘will be jailed’ morally illegal.”As if, not the judge but the rulers are determing the kind of verdict [to be delivered against me],” said the BNP chair.In this context, she expressed her suspicion whether the judge would be courageous to deliver justice since the chief justice was forced to leave the country and resign very recently.”I would like to inform the countrymen with pride that your Khaleda Zia did not do anything wrong. I didn’t commit any corruption,” she said.Rather, Khaleda Zia alleged, the ruling party men looted public resources worth millions. “Such scams are not probed; even if it is probed, the report is not made public,” she said, adding that the Awamie League regime stopped all means of protests against all its misdeeds.The BNP chief alleged that the AL government had turned the justice delivery system into a farce by acts of politicisation and intimidation.
The Executive Committee of the National Economic Council (ECNEC) holds meeting on Tuesday. Photo: UNBBangladesh is going to construct ‘border roads’ in hilly areas along the India-Myanmar border with a view to ensuring better security through improved road communications.The Executive Committee of the National Economic Council (ECNEC) on Tuesday approved a project titled ‘Construction of Border Roads’ involving over Tk 16.99 billion to this end, reports UNB.ECNEC chairperson and prime minister Sheikh Hasina chaired the meeting held at the NEC conference room in Dhaka.While briefing reporters after the meeting, planning minister AHM Mustafa Kamal said the road and highways department and the special works organisation of Bangladesh army have been given the responsibility to implement the project.The project will be completed in six upazilas of Khagrachhari, Bandarban, Rangamati and Cox’s Bazar districts by June 2021.The project will be implemented at Naikhongchhari upazila in Bandarban, Juraichhari, Borkol and Rajstali upazilas of Rangamati, Ukhiaupazila of Cox’s Bazar and Baghaichhari upazila of Khagrachhari.Out of the proposed 317-kilometre roads, some 40 kilometres will be constructed on the Ukhia-Ashartoli-Fooltuli route, 52 kilometres on the Sajek-Shildah-Betling, 95 kilometres on Sajek-Dokanghat-Thegamukh, and 130 kilometres on Thegamukh-Loitongpara-Thachhi-Dumdumia-Rajsthali route.Bangladesh has around 540 kilometres borders — 330 kilometres with India and 210 kilometres with Myanmar.On implementation of the project, border guards are expected to be able to ensure strict measures in hilly border areas, curb illegal drugs and arms smuggling through improved road communications.This project will also help expand trade and commerce, develop tourism facilities in hilly areas, facilitate marketing of agricultural products to boost economic activities and generate employment opportunities.The planning minister said 16 projects were approved today with an overall estimated cost of more than Tk 96.80 billion.Of the approved 16 projects, 12 are new while four are revised ones.
Aerial view of a burned Rohingya village near Maungdaw, north of Rakhine state, Myanmar September 27, 2017. REUTERSRepresentatives of UN agencies will be permitted to visit Rakhine state in Myanmar on Thursday for the first time since the start of a massive exodus of minority Rohingya Muslims.The United Nations has been demanding access since its humanitarian organizations were forced to pull out of Rakhine when Myanmar’s military launched operations against Rohingya rebels in late August, causing hundreds of thousands to flee into neighboring Bangladesh.“There will be a trip organized by the government, probably tomorrow, to Rakhine,” UN spokesman Stephane Dujarric said.“We hope above all that it is a first step toward much freer and wider access to the area,” he said at his daily news briefing.He said the chiefs of UN agencies would take part in the trip.The UN has drawn up a contingency plan to feed up to 700,000 Rohingya refugees from Myanmar, and warned that those who fled will not be returning home soon.“All the UN agencies together have now set a plan for a new influx of 700,000. We can cover if the new influx reaches 700,000,” the World Food Program’s deputy chief in Bangladesh, Dipayan Bhattacharyya, said on Wednesday.‘Return will take time’ -UN refugee agency chief Filippo Grandi said that for those who have fled to Bangladesh, “return will take time, if it happens, if the violence stops.”Myanmar’s military, under fire for imposing a news blackout on the campaign around the city of Maungdaw in the country’s west, on Wednesday organized a press tour in the Hindu village of Ye Baw Kyaw.Mass graves containing 45 Hindu villagers were discovered in the area earlier this week, and the military has accused Rohingya militants of carrying out the massacre.The Arakan Rohingya Salvation Army (ARSA) “categorically” denied that its members “perpetrated murder, sexual violence, or forcible recruitment” in the area.The decomposing skeletal bodies remained laid out in rows on a grassy field outside Ye Baw Kyaw as distraught relatives wailed, according to AFP journalists at the scene.Hindus who fled the area have told AFP that masked men stormed into their community and hacked victims to death with machetes before dumping them into freshly-dug pits.Myanmar’s army has tried to control the narrative over the crisis, restricting press access to the conflict zone while it posts regular updates that blame Rohingya militants for the bloodshed.Government and military reports have also sought to highlight the suffering of other ethnic groups, such as Rakhine Buddhists and Hindus, swept up in the communal unrest.Ethnic cleansing accusations -The latest violence has intensified long-running religious hatreds and been complicated by a swirl of rival narratives from different ethnic groups.Thursday’s visit for the UN representatives will come on the same day that the UN Security Council meets on the situation in Myanmar.On September 13, the council demanded “immediate steps” to end the Myanmar violence and expressed concern about “excessive force” being used by the military.The council also called on the Myanmar government to abide by its commitment to facilitate humanitarian aid in Rakhine, but until now that request has not been met.Secretary General Antonio Guterres will address the UN Security Council during its open door session. As a former UN high commissioner on refugees, Guterres knows Rakhine and the context of the current crisis intimately.With accusations of “ethnic cleansing” being leveled at the UN General Assembly, Myanmar leader Aung San Suu Kyi said last week she was “ready” to organize the return of the Rohingyas.The Rohingyas, the world’s largest stateless group, are treated as foreigners in Myanmar, whose population is 90 percent Buddhist.
Democratic 2020 US presidential candidate and former vice president Joe Biden speaks during a campaign stop in Philadelphia, Pennsylvania, US on 18 May. Photo: ReutersSeeking to build on early momentum in his 2020 presidential bid, former US vice president Joe Biden on Saturday condemned “anger” within his own Democratic Party and pledged to work to unify the country in the wake of Donald Trump’s presidency.At a rally in downtown Philadelphia, Biden, as he has done throughout the beginning stages of his campaign, made Trump his central target, blasting him as “the divider-in-chief.”But he also chided other Democratic presidential candidates in the field, suggesting that anger toward Trump within his party was not enough to win next year’s presidential election.His message, Biden said, was expressly aimed at Democratic, Republican and independent voters alike.”Some of the really smart folks say Democrats don’t want to hear about unity,” he said. “They say Democrats are so angry, and that the angrier your campaign will be, the better chance you have to win the Democratic nomination. Well, I don’t believe it.”About 6,000 people attended the rally, which had, by design, the feel of a general-election event. With his poll numbers currently swamping the rest of the Democratic field, Biden has often acted as if his current opponent is Trump and not the other 23 Democrats vying for the party’s nomination.”If the American people want a president to add to our division, to lead with a clenched fist, closed hand, a hard heart, to demonize the opponents and spew hatred – they don’t need me, they’ve got President Donald Trump,” Biden told the crowd, which was bookended by large video monitors.Democratic nominating contests begin next February, giving the dynamics of the race plenty of time to shift. But Biden, 76, has opened up a more than 20-point lead over his nearest rival, US senator Bernie Sanders, in several public opinion polls.Biden, a US senator for 30 years and a two-term vice president under Barack Obama, has argued he is best positioned to take on Trump next year.Attendees at the event said they agreed.”He’s going to be the one who takes Trump out of office,” said Daril Murard, 27, of Langhorne, Pennsylvania. “That’s why I’m here.”Tim Reihm, 48, drove to the event from his hometown of York, Pennsylvania.”I think there’s been a tendency in the party to drift a little too far left and I think that’s going to disenfranchise a large section of the country,” Reihm said. “Joe represents a sort of a more middle ground where we can bring people together instead of becoming more and more fractious.”Biden also answered critics who have mocked his pledge to work with Republicans as unrealistic should he win the White House.”I’m going to say something outrageous,” he said. “I know how to make government work.”Biden’s remarks drew a swift response from the Progressive Change Campaign Committee, a liberal advocacy group that backs another candidate, US senator Elizabeth Warren.A fundraising memo sent to members after the rally accused Biden of trying to splinter the party.”Joe Biden is dividing Americans when, after the historic 2018 election, he tells voters they are wrong to be angry – and wrong if they don’t want ‘unity’ with corrupt Republican politicians,” the memo said.”We don’t need a Democratic nominee who rejects the fact that people are righteously angry in the Trump era,” it said.Biden has established his campaign headquarters in Philadelphia, illustrating the importance of Pennsylvania to Democratic hopes next year. Trump narrowly won the state over Hillary Clinton in 2016.Trump will hold an event of his own on Monday in northeast Pennsylvania.Prior to Biden’s speech, the Republican National Committee in a release pointed to statistics showing how Pennsylvania’s economy has improved during Trump’s presidency.Biden will not have the luxury of shrugging off the rest of the Democratic field much longer.In recent weeks, he has been criticized by Senator Kamala Harris for his past support for the 1994 crime bill that critics say led to mass incarceration of African-Americans, by Sanders for his support of the North American Free Trade Agreement, and by Warren for his ties to the credit-card industry.With Biden the clear front-runner, those attacks are likely to intensify. But Biden on Saturday said he would keep his focus on Trump and not his rivals for the nomination.”You will not hear me speak ill of another Democrat,” Biden said.Following the Philadelphia event, Biden is expected to spend the next several weeks focusing on policy announcements and raising money.
Alex Wong/Getty ImagesThen-FBI Director Robert Mueller testifies during a hearing before the House Judiciary Committee on June 13, 2013, on Capitol HillThe man leading the Justice Department’s investigation into Russian interference in the 2016 election has been keeping busy.Special counsel Robert Mueller has been on the job for about nine months. But he has already charged 19 people with wrongdoing — and won guilty pleas from the president’s former campaign vice chairman and his former national security adviser.Scholars who focus on politically charged investigations that may lead into the White House have been taking note.“Robert Mueller’s pace in this investigation really is very similar to some of the best special prosecutors in modern history,” said Ken Gormley, the president of Duquesne University and the author of two books on special prosecutors.These investigations carry special burdens: to move forward quietly, with no leaks, and quickly, to prove guilt or innocence.“The whole point of appointing an independent counsel in these kind of instances is to deal with the fact that there’s a cloud over the highest levels of the executive branch and to restore public confidence, one way or the other,” Gormley said.For many people, the model prosecutor was Archibald Cox, who investigated Watergate for a little more than a year before he was fired.“I’m not looking for a confrontation,” Cox told reporters in 1973. “I’ve worried a good deal through my life about the problems of imposing too much strain upon our constitutional institutions and I’m certainly not out to get the president of the United States.”During his tenure, Cox developed evidence about obstruction of justice by President Richard Nixon. The prosecutor who replaced Cox built on that work, ultimately leading to Nixon’s resignation.Gormley said the current special prosecutor, Robert Mueller, is operating in that same mold.But at the White House, President Trump and his lawyers have been pressing the Mueller team to move faster. So is another familiar figure: former Whitewater independent counsel Ken Starr.“The American people, I think, want to know, was there collusion,” Starr told CNN last week. “Let’s get that answered. That would be my sense, if I were at the Justice Department.”Starr spent five years and more than $40 million investigating President Bill Clinton. Critics say Starr took too long and wandered away from his original mission. He was far from the only independent counsel to come under attack as a “roving Frankenstein monster,” Gormley said.In the category of “no end,” there was the investigation of Clinton’s secretary of Housing and Urban Development, Henry Cisneros. In 1995, then-Attorney General Janet Reno asked for an independent counsel to determine whether Cisneros should face prosecution for providing false information about payments to a former mistress.“I’m disappointed by that outcome but I’m hopeful that the investigation will be completed expeditiously,” Cisneros told reporters at the time.But any hope Cisneros had for a speedy resolution went bust. The independent counsel in his case, David Barrett, kept working even after the law authorizing his work expired. Cisneros pleaded guilty to a misdemeanor charge and was later pardoned by the president. Still, Barrett’s work continued. The final report emerged in 2006, nearly 11 years after he took office.Robert Mueller is a hard-driving former FBI director, not known for dallying in his work. He’s already secured indictments against Russians for running an information warfare campaign aimed at the last presidential election.And yet, Wake Forest University professor Katy Harriger said measuring Mueller’s success will be a challenge.“For some people, success will only be if somehow the president gets impeached,” Harriger said. “And for other people, success is a complete exoneration.”Push away that cloud of politics, she said, and success may be a report or a set of conclusions that most people can believe.Copyright 2018 NPR. To see more, visit http://www.npr.org/. Share
firstname.lastname@example.org Del. Antonio Hayes has submitted a bill to the General Assembly to raise the maximum fine for a first-time offense of selling alcohol to minors in Baltimore City. (Photo courtesy of Del. Antonio Hayes)Baltimore City has the lowest maximum fine – tied with Calvert County – for a first-time offense of selling alcohol to minors. Del. Antonio Hayes (D-Baltimore City) has introduced a bill in the General Assembly to double the current maximum fine, from $500 to $1,000.“This bill, like other pieces of my legislation, is really the brainchild of people in communities that I represent,” said Hayes, who tells the AFRO that his bill was spurred by the advocacy of Dr. Marvin Cheatham, president of the Matthew A. Henson Neighborhood Association, on the issue of liquor sales to minors.Currently, in Baltimore City, the Board of Liquor License Commissioners (BLLC) can impose a fine of up to $500 on an establishment for its first offense of selling alcohol to minors. Subsequent offenses allow a maximum fine of $3,000, and Hayes says his bill, House Bill 868 (HB0868), would simply put the initial fine more on par with the fine for subsequent offenses.Baltimore City’s current maximum fine is well below that of other counties in the state, according to the freshman delegate. In adjacent Baltimore County, the maximum fine for a first offense of selling alcohol to minors is $2,000. In Prince George’s it is $12,500, and in Montgomery County it is $20,000, says Hayes.“Most liquor stores, $500 is what they do in two to three hours, so it’s not really sending them a message of the importance of [not] serving alcohol to minors,” said Hayes.Cheatham tells the AFRO that there are 15 establishments selling or serving alcohol in the vicinity of his neighborhood, four of which were fined last year for selling alcohol to minors.“What we were seeing was not only violence and crime associated with the liquor stores, but we were beginning to see an uptick in the sale of liquor to young people because they weren’t checking the IDs,” said Cheatham, who says the current BLLC has been more aggressive in policing sales to minors, but that its penalties need more teeth.“Where it is now . . . that’s far too little when you consider you sold liquor to a minor,” said Cheatham.According to Michelle Bailey-Hedgepeth, executive secretary of the BLLC for Baltimore City, 44 establishments were fined for selling alcohol to minors in fiscal year 2013, with approximately 75 establishments being fined for, or charged with, selling alcohol to minors in fiscal 2014 (running from July 1, 2014 to June 30, 2015).The process for fining an establishment begins with a police vice operation, generally involving an underage cadet, who attempts to purchase alcohol. If the undercover cadet is not ID’d and sold alcohol (or sold alcohol despite an ID showing the cadet was underage), the police file a report with BLLC who then holds a hearing to determine guilt and the appropriate fine.“Last year [vice] visited approximately 150 locations throughout the city,” said Bailey-Hedgepeth.“The majority of the liquor stores and taverns in the district are responsible establishments,” said Hayes, “it’s just that there’s a couple of bad apples that are not responsible, so this [bill] is really to go after the ones who are not being responsible.”Because HB0868 simply raises the maximum fine that can be assessed against an establishment for a first offense of selling alcohol to minors, the bill has no direct costs for implementation.
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. At left, the drawing of the LET describes the scientists’ observation, shown in the electroluminescence intensity map at right. The infrared light emitted from the LET reaches the detector, meaning that an electrical signal can be transferred to the detector by light. Credit: Shin-ichi Saito, et al. In one of the early discoveries of the current “silicon electrophotonics era,” scientists from Hitachi, Ltd. in Tokyo have built a light-emitting transistor (LET) that transfers, detects and controls an electrical signal all on a single nanometer-sized chip. Using a silicon-on-insulator (SOI) substrate, the group could optically connect the LET to a detector, resulting in a tiny chip that may integrate a wide range of microelectronics and photonics nano devices. Citation: Light-emitting transistor uses light to transfer an electrical signal (2006, November 1) retrieved 18 August 2019 from https://phys.org/news/2006-11-light-emitting-transistor-electrical.html “With LETs, we could develop an optical interconnection beyond the present copper interconnection,” Shin-Ichi Saito, co-author of the study in Applied Physics Letters, told PhysOrg.com. “If LETs are really integrated on silicon chips, we might reduce power dissipation (since light does not have electrical resistance), as well as RC [Resistive Capacitive] delay: in electrical circuits, the interlayer coupling capacitance reduces the speed of electrical signals, while such a delay might be reduced in optical interconnections.”Similar to a standard field-effect transistor, Saito et al.’s LET takes advantage of some interesting properties of 2D electron and electron hole systems, called “quantum confinement effects.” By reducing the thickness of the crystal silicon down to the nanometer scale, the scientists fabricated an ultra-thin single crystal silicon film, directly connected to the thick silicon electrodes. In such a design, n-type (electrons) and p-type (holes) semiconductors lie next to each other separated by a narrow junction. As the electrons and holes efficiently eliminate each other in a process called “recombination,” photons are emitted; thus electrical signals can be converted to optical signals. This close-up drawing of the LET shows the ultrathin silicon junction acting as a quantum well. After recombination, the electric carriers are confined into a standing wave, greatly increasing the electroluminescence efficiency. Credit: Shin-ichi Saito, et al. Explore further “The key idea is that the 2D conduction band electrons behave just like electrons in direct band-gap semiconductors,” said Saito. “In bulk Si, the conduction band electrons move very fast with a large momentum. However, in the ultra-thin Si, the electrons cannot move perpendicular to the substrate with such a large momentum, simply because that direction is restricted. Many people also consider that this quantum mechanical confinement plays some role for the enhanced luminescence in nano-scale silicon.”To optically interconnect this electrical signal from the LET to a detector–which were electrically isolated but on the same silicon chip–the group applied a forward voltage bias to the LET. The scientists observed the light from the LET to reach the photodetector, and measured the “photocurrent” in the detector to increase with a voltage increase, and decrease when the voltage was turned off (detector limitations caused some current to continue flowing).Although the Hitachi group points out limitations to the present experimental set-up that need to be fixed before applying the principle to marketable technology, they suggest solutions for these problems: for example, reducing the response time of the detector and using waveguides to contain the light on the chip. However, the achievement shows how, using curious phenomena of quantum mechanics, photons, just like electrons, can be manipulated on a silicon chip. Quite possibly, future integrated circuits may use lights instead of currents to enhance performance while reducing power dissipation.“We have just confirmed the basic operation principle for this LET,” said Saito. “The hope is that this is just the beginning of more research; we have lots to do.”Citation: Saito, Shin-ichi, Hisamoto, Digh, Shimizu, Haruka, Hamamura, Hirotaka, Tsuchiya, Ryuta, Matsui, Yuichi, Mine, Toshiyuki, Arai, Tadashi, Sugii, Nobuyuki, Torii, Kazuyoshi, Kimura, Shin’ichiro, and Onai, Takahiro. “Silicon light-emitting transistor for on-chip optical interconnection.” Applied Physics Letters 89, 163504 (2006).By Lisa Zyga, Copyright 2006 PhysOrg.com “With the lateral carrier injections that we used, we can efficiently inject both electrons and holes directly in the quantum confined silicon,” said Saito. “Usually, nano-scale silicon structures are passivated by SiO2, which has huge potential barriers for carriers. Such a limitation does not exist in our device.”In this set-up, the p-n junction consists of a light-emitting diode (LED) made of ultrathin silicon. At a 9nm thickness, the silicon acts as a quantum well, confining the electric carriers to two dimensions, which forms a standing wave consisting of an electron. This confinement serves an especially useful purpose for integrating optical components into silicon circuits, as it enhances the electroluminescence efficiency of the junction. While other LETs–from carbon nanotubes and organic models to semiconductor and nanocrystal devices–have been demonstrated, Saito et al.’s is the first in which recombination occurs along the silicon junction and takes advantage of quantum confinement’s electroluminescence. Decline of entrepreneurship blamed for Japan woes
But R. Dean Astumian, a Physics Professor at the University of Maine, has recently proposed a concept in which molecular machines can operate arbitrarily close to chemical equilibrium at every instant of the cycle, and still perform work at the rate of several micrometers per second against piconewton loads. The study, “Adiabatic operation of a molecular machine,” is published in a recent issue of the Proceedings of the National Academy of Sciences.“The main significance is conceptual – it changes the way we think about molecular motors,” Astumian told PhysOrg.com. “Much emphasis has been put on the ‘non-equilibrium’ aspects of the system, but in fact this is not really important. The motion of the rings here arises due to a combination of topology that break spatial symmetry, and the slow external modulation that breaks time symmetry. It is also important to recognize that, in the molecular world, we can truly have motors that operate with nearly 100% efficiency.”Astumian’s example of such a molecular machine is a three-ring “catenane” structure that serves as a rotating motor. The catenane, about 3 nanometers in diameter, consists of one large ring with two smaller rings linked to the large ring, like rings on a keychain. Three binding stations on the large ring provide locations where the two small rings can bind, depending on the interaction energy between ring and station. Astumian gets the small rings to move clockwise from station to station around the large ring, a movement that results in mechanical cycling. Further, he achieves this movement without any heat gain or heat loss and without a change of entropy, but simply by thermal noise due to Brownian motion. This type of “adiabatic” system is arbitrarily close to equilibrium at every point of the cycle.The key to making the small rings move from station to station is by periodically modulating the interaction energy. The rings will bind to the station that requires the lowest interaction energy. This modulation must be done slowly enough not to generate heat, but at a sufficient rate to produce significant work. Slowly modulating the energy of a single molecule is challenging, and Astumian explains that it is nearly impossible to do with chemical systems. However, the net interaction energy for many molecules can be slowly modulated by very slow titrations of pH and redox potential. For example, a condition that is strongly acidic and strongly reducing corresponds with high interaction energy at station 2. Therefore, the two rings will bind at stations 1 and 3. Explore further Molecular machines – tiny machines made of molecules that do mechanical work – are usually thought to operate in a state of non-equilibrium. This makes sense, considering that macro-sized machines operate at non-equilibrium, requiring an additional force to move. On the other hand, equilibrium implies that forces cancel each other out, resulting in an unchanging system, often at rest. Then, by titrating with oxidant to reach a strongly oxidizing and strongly basic condition, the energy at station 1 is highest. So the rings now occupy stations 2 and 3. Astumian explains that the rings could switch to this state by either the ring at station 1 moving clockwise to bind at station 2, or the ring at station 3 moving counter-clockwise to bind at station 2. However, after more modulations, the majority (about 75%) of the movements will be clockwise due to the changing energy levels at different stations. By figuring this probability, Astumian concludes that, every time the small rings move around the large ring, the system will complete one-half of a mechanical rotation.He also mentions that there might be more creative architectures where counter-clockwise motions don’t undo the clockwise motions. He likens this mechanism to a ratcheting screwdriver used to drive a screw. When the ratchet turns counter-clockwise to reset itself, it releases so that it doesn’t undo the forward turn of the screw. Although a molecular machine would use thermal noise instead of external torque, the concept is similar. In the molecular machine, one of the small rings could be fixed to prevent counterclockwise motion.“I would say that the biggest challenge is to arrange the molecules on a surface so that the movement can be used to do work on the outside world,” Astumian said. He added that the chemical structures have already been synthesized by David Leigh at the University of Edinburgh, as the next step in the development of the machines.Astumian also explains that operating this system requires a fine balance between modulating slowly enough so that the system is in chemical and mechanical equilibrium at every instant, but rapidly enough to perform substantial work. While biomolecular motors are often described in “violent” terms, he hopes that this “kindler, gentler” description may be more appropriate for designing more efficient molecular machines.“I plan to extend the theory to explain the mechanism of biological motors,” Astumian said. “While they doubtless do not operate exactly by the mechanism described for the three-ring catenane, I think the flavor of how they operate is much better characterized by this near-equilibrium description than by various biological models involving cars, judo throws, and steam engines.”More information: Astumian, R. Dean. “Adiabatic operation of a molecular machine.” PNAS, December 11, 2007, vol. 104, no. 50, 19715-19718.Copyright 2007 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. Illustration of the possible transitions for a catenane structure that consists of one large ring with three stations for two small rings. The two small rings move around the large ring to bind at a station. Each binding state is favored by a different energetic condition, as indicated. ©2007 PNAS. Image credit: R. Dean Astumian. Citation: ‘Kind and Gentle’ Molecular Machine Could Operate at Near-Equilibrium (2007, December 20) retrieved 18 August 2019 from https://phys.org/news/2007-12-kind-gentle-molecular-machine-near-equilibrium.html SLAC makes ‘electron camera,’ a world-class tool for ultrafast science, available to scientists worldwide 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.
France’s AB Group is to make its full portfolio of channels available to distribution partners in full HD from today and is shutting down standard-definition transmission of the services.Canalsat will offer four of the HD channels – RTL9, Cine FX, Action and Animaux – to its subscribers.AB Group said the migration had presented a major technical challenge that required significant investment on its part, but that it would position it amongst the major providers of full HD channels in France.Separately, France’s media regulator, the CSA, is to hear an appeal by factual channel Planète to migrate from the pay to the free tier of channels on the country’s digital-terrestrial TV platform on June 3.