Ten Italian scientists have a novel idea. They want to hitch up their wagons to bacteria and use them to power nanomachines. It’s too much work to build such “perfect machines” from scratch, they said. Why not just take advantage of what nature has already provided? Their paper in PNAS1 is downright dreamy about the possibilities of using flagella-equipped bacteria as motors for their machinery:Self-propelling bacteria are a nanotechnology dream. These unicellular organisms are not just capable of living and reproducing, but they can swim very efficiently, sense the environment, and look for food, all packaged in a body measuring a few microns. Before such perfect machines can be artificially assembled, researchers are beginning to explore new ways to harness bacteria as propelling units for microdevices. Proposed strategies require the careful task of aligning and binding bacterial cells on synthetic surfaces in order to have them work cooperatively. Here we show that asymmetric environments can produce a spontaneous and unidirectional rotation of nanofabricated objects immersed in an active bacterial bath. The propulsion mechanism is provided by the self-assembly of motile Escherichia coli cells along the rotor boundaries. Our results highlight the technological implications of active matter’s ability to overcome the restrictions imposed by the second law of thermodynamics on equilibrium passive fluids.That’s an interesting term for a living cell – “active matter.” From an engineer’s viewpoint, a bacterium can be considered a little bit of energetic matter that has figured out how to overcome the second law of thermodynamics, at least locally and temporarily. They do it by converting biochemical energy into mechanical motion. All engineers need to figure out is how to apply this active matter in asymmetric ways so that work can be done at the nanometer scale with a kind of “Brownian ratchet” effect (see 04/19/2010). The team ran some proof-of-concept experiments with tiny gears immersed in an active bath of motile E. coli cells. They got their bacterial helpers to turn the gear at 2 rpm. In contrast to previous attempts that tried to channel the bacteria along guided tracks (09/06/2006), this team relied on a self-organizational method. “We demonstrate that the underlying off-equilibrium nature of a bacterial bath allows one to rectify the chaotic motions of bacteria by geometry alone,” they said, implying that the pre-imposed design in the setup brings the order out of the chaos. “Once the microstructures are fabricated with a proper asymmetric shape, no further chemical patterning or externally induced taxis is needed to produce a directional and predictable motion.” A dream of great physicists may soon become a reality, thanks to our little cellular friends:The idea that, in nonequilibrium states, a directional motion can arise from the chaotic dynamics of small molecules was first put forward by [Richard] Feynman in his famous “ratchet and pawl” thought experiment . The combination of asymmetry and nonequilibrium was soon recognized to be at the origin of the “ratchet effect,” opening the way to the stimulating concept of Brownian motors in physical and biological contexts. Many ways have been considered to drive a system out of thermal equilibrium, such as cycling temperature or applying time-dependent external fields. Our experiment demonstrates an intriguing realization of a ratchet mechanism, where bacteria can be thought of as intrinsically off-equilibrium “molecules.” Asymmetric environments can be used to break the remaining spatial symmetries and allow the emergence of an ordered, reproducible motion that could serve as the driving mechanism for completely autonomous, self-propelling microdevices. Applications at the micrometer scale, such as self-propelling micromachines or pumps and mixers for microfluidics, are the most promising, but it will also be important to answer the question whether bacterial motors are confined to the microworld, or we can think of a macroscopic exploitation of bacteria as mechanical power sources.Now that’s a dream; imagine bacteria as power sources for our automobiles. How many flagella would that take? The paper was edited by Howard Berg of Harvard, one of the pioneer investigators of the bacterial flagellum. The authors made no mention of evolution.1. Di Leonardo et al, “Bacterial ratchet motors,” Proceedings of the National Academy of Sciences published online before print May 10, 2010, doi: 10.1073/pnas.0910426107.Evolution? They had no need of that hypothesis. We hate to keep rubbing this in, Eugenie, Ken, Richard, Jerry, and Francisco, but the first step in recovery is to admit you have a problem. We know it will get depressing when nobody calls wanting to hear your rendition of the Theodosius Soliloquy,* and the universities can’t attract bright students fast enough to enter their biomimetics labs. But you can still have a future in the Design Age. Find a hobby; plant tomatoes, try art, take a hike. Life will go on.(Visited 12 times, 1 visits today)FacebookTwitterPinterestSave分享0
The Home Innovation Research Labs (HIRL) does an annual survey of home builders that includes what types of homes they are building and how they are building them. The results of their 2019 survey of the homes built in 2018 are out now, and they recently published an interesting article about the breakdown of different insulation materials used by home builders. Before we talk about the implications, let’s see what they found. Here’s the pie chart showing the different insulation materials builders are installing in single-family homes. (The SF in the title below stands for “single family.”) Insulation materials ranked by their use by home builders. Chart courtesy of Home Innovation Research Labs.As you can see, fiberglass is the dominant insulation material. Altogether, 71% of all the insulation used by the 1600 builders surveyed is fiberglass, 52% of it in the form of batts and 19% of it blown-in. According to the article, fiberglass has held fairly steady at that level for the past few years.RELATED ARTICLES(At Least) Four Things Are Wrong With This PictureBlown Insulation for Attics: Fiberglass vs. CelluloseCompetitors Ready New Generation CelluloseWhat’s More Important, Air-Sealing or Insulation?Building an Airtight Envelope Since this material makes up more than two thirds of the insulation market for new, single-family homes, this is a good time to review the problems, myths, and best practices associated with fiberglass. Problems with fiberglass insulation There’s really only one problem with fiberglass: poor installation. OK, it also can be really itchy if you get it on your skin and it’s a lung irritant if you’re working with it and not wearing a mask or respirator. So wear proper protective gear when you’re installing it or crawling around in a space with exposed fiberglass. But the installation problem is well documented here and many other places. Since 2006, there’s been an insulation installation grading protocol, with grade 1 being the best and grade 3 being the worst. What I’d like to see HIRL add to their survey is how much of all that fiberglass installed each year is installed to grade 1, how much to grade 2, and how much to grade 3. If you insulate a standard 2×4 wall with fiberglass, the average R-value drops about 12% when you install to grade 3 compared to installing it to grade 1. Yeah, when you go from R-11.8 to R-10.3, you still have a much better wall than older homes with no insulation in the walls, which would be about R-3.7. And you won’t see much of a hit from that on your monthly bills. But those little bits add up. Grade 3 insulation installations can cost thousands of dollars in heating and cooling costs over the life of the home. And for a lot of that insulation, you get one chance to do it right before the house gets remodeled or torn down. Myths about fiberglass insulation I love a good myth as much as anyone, and there are some doozies out there in the world of fiberglass insulation. Here’s my number one all-time favorite: Myth: Fiberglass-insulated homes are too leaky, resulting in high energy bills and comfort problems. Whoa, there! Yes, fiberglass is an air-permeable insulation and many houses in which it’s been installed are definitely too leaky. But this is like blaming your stale, moldy candy bar on the ingredients rather than the fact that you bought one with a shredded wrapper. A properly designed and installed building enclosure needs to have well thought-out control layers for heat, air, and moisture. Fiberglass is a perfectly fine control layer for heat, but it’s not going to stop air movement. That’s the job of the air barrier. You need both. Myth: Fiberglass insulation causes cancer. In the late 1980s, the National Toxicology Program and the state of California declared fiberglass a possible carcinogen. That was based on early studies that later were shown not to be accurate. In 2011, both removed fiberglass insulation from their lists. Read more about it in this National Insulation Association article. Oh, by the way, fiberglass is second only to cork as a healthy insulation material. See the table in Lloyd Alter’s article on the HIRL survey to see how it ranks. Myth: Blown fiberglass attic insulation performs poorly because of convective loops. I’d heard this one for many years before I finally wrote about it. Yes, there was a study from the early 1990s that showed blown fiberglass in attics could lose 50% of its R-value when the attic temperature dropped. The problem was the way the insulation was made, and the fiberglass industry fixed the problem. See this article for more details. Myth: Compression in fiberglass insulation is a bad thing. This is another persistent one, and I have to admit that I fell for it for a while, too. The truth is that compressed insulation does have a lower R-value than that same insulation expanded to its full thickness. Here’s what I wrote in my article on this topic in 2017: Compression isn’t the problem. Incompletely filled cavities are a problem. Gaps are a problem. But you can compress fiberglass insulation as much as you want. The North American Insulation Manufacturers Association (NAIMA) has a little two-page document about compressing fiberglass insulation. Here’s what they say: “When you compress fiberglass batt insulation, the R-value per inch goes up, but the overall R-value goes down because you have less inches or thickness of insulation.” If you’re filling the cavity and getting the R-value you want, compression doesn’t matter. Best practices for fiberglass insulation If you have any say in the design or installation of the insulation in your home, here’s a bit of guidance for you. I’m focusing on fiberglass here but the same things apply to most of the alternatives, too. I’ll break it down by what kind of assembly is being insulated, starting at the bottom. Floors Don’t use fiberglass batts to insulate floors. It’s practically impossible to get a grade 1 installation with them. If the floor joists are open to below (as over a crawlspace), move the building enclosure to the walls and ground/slab by encapsulating the crawlspace or use spray foam, which won’t fall down. If you’re insulating a floor over a garage or over outdoor air and the cavities will be completely closed, fill the cavities with blown fiberglass. If there are relatively few obstructions in the cavities and the joists are dimensional lumber rather than I-joists or open-web trusses, batts can work. Again, best is to fill the whole cavity. Air-seal all penetrations in the floor assembly. Remember that fiberglass needs a continuous air barrier. Walls Both batts and blown can work fine if you fill the cavity completely. With batts, cut around junction boxes and put the cut out piece behind the junction. Split batts around wires. Cut batts around pipes, blocking, and other obstructions. Use unfaced batts whenever possible. They’re easier to install properly as well as easier to inspect. Put an air barrier on the attic side of kneewalls (or eliminate kneewalls by encapsulating the attic). Ceilings Blown insulation is better for filling the joist cavities. When installing batts, follow the guidance above for walls when it comes to fitting the batts in the cavities. Choose batts that are the same thickness as the depth of the joist cavities. To get more R-value, add another layer of batts, running them perpendicular to the joists, or blow insulation on top. (There’s a reason most attics have blown insulation, not batts.) Make sure the blown insulation reaches the minimum thickness necessary for the design R-value. Some contractors like to deliver average thickness, but that can result in significant underperformance of your insulation, as I described way back in 2010 when I wrote, Flat or Lumpy – How Would You Like Your Insulation? The big takeaway I’ve written many articles about insulation, a lot of them about fiberglass or applicable to fiberglass. The most important thing I want you to take away from this article today is that you need to understand fiberglass—or any insulation material, really—to get the most out of it. As I wrote above, the main problem is poor installation. Learn the truth behind the myths so you can dismiss them. And then follow the best practices I outlined above. Fiberglass is a perfectly fine insulation material with a bad rap because of all the sins committed—or said to be committed—in its name. Learn the truth, do it right, and you’ll be healthy, wealthy, and comfortable…or at least a bit closer! Allison Bailes of Decatur, Georgia, is a speaker, writer, building science consultant, and the author of the Energy Vanguard Blog. You can follow him on Twitter at @EnergyVanguard.
Stating that universities in the State should not merely function as institutions doling out degrees, Chief Minister Devendra Fadnavis on Thursday urged varsities to build themselves into centres of innovation.“We see universities as hubs of innovation and not merely as institutions giving out degrees. If we fail to generate merit in our varsities, then we will not be able to build a competent human resource force. Hence, I appeal to all universities to focus more on skill development,” he said, pointing out that the service sector was set to grow massively in the near future owing to a number of provisions announced in the recent Union Budget.Mr. Fadnavis was speaking in Solapur district on the occasion of the groundbreaking ceremony for the new administrative building and exam centre of the district’s Punyashlok Ahilyadevi Holkar Solapur University.“It is the responsibility of a university to churn out a skilled workforce in order to build the economy,” said the Chief Minister, who also approved of setting up of a chair named after Ahilyadevi Holkar, the legendary 18th century queen, at the varsity while assuring funds for its expansion activities.Mr. Fadnavis later performed the groundbreaking ceremony for a housing scheme project for journalists in Solapur.“Our government has already extended the coverage of Mahatma Phule JanArogya Yojana to journalists and now, a pension scheme for them will be implemented in a month’s time,” he said, speaking on the occasion.Stating that the BJP-Sena government was working extensively to implement housing schemes in the state for every section of society, he remarked that the government was eager to provide affordable housing to journalists in every district in Maharashtra and was currently working on it.A total of 238 houses are to be constructed with the help of the Maharashtra Housing and Area Development Authority (MHADA) under the Pradhan Mantri Awas Yojana (PMAY) scheme for the Solapur Working Journalist Housing Society.Mr. Fadnavis was in the district ahead of the annual puja (worship) of Lord Vitthal in the temple town in Pandharpur. Mr. Fadnavis will offer worship early morning Friday. Last year, the quota agitation by Maratha outfits had compelled Mr. Fadnavis to cancel the annual worship event.
Three personnel of 120 Border Security Force were seriously wounded on Saturday night when a powerful remote controlled bomb was detonated near Telipati, Imphal east district in Manipur, at 11:30 p.m. The personnel were taken to the J.N. Institute of Medical Sciences in the same district.No underground organisation has claimed responsibility for the blast.There is a permanent police picket at Telipati which is dominated by people originating from Bihar. Police have registered a case. So far there is no breakthrough in the investigation.
FC Barcelona’s Lionel Messi competes for the ball with players from SD Eibar’s Cote during the Spanish La Liga soccer match between FC Barcelona and SD Eibar, at Ipurua stadium, in Eibar, northern Spain, Saturday, Feb.17, 2018. (AP Photo/Alvaro Barrientos)LONDON — As unlikely as it sounds, Lionel Messi is still waiting to score his first goal against Chelsea after drawing a blank in eight previous Champions League matches.The five-time World Player of the Year is likely to get another chance to break his duck this week and Chelsea manager Antonio Conte believes the past will count for little when Barcelona visits Stamford Bridge on Tuesday.ADVERTISEMENT NEXT BLOCK ASIA 2.0 introduces GURUS AWARDS to recognize and reward industry influencers Read Next Typhoon Kammuri accelerates, gains strength en route to PH SEVILLA-MAN UNITEDFrance midfielder Paul Pogba missed Saturday’s 2-0 FA Cup fifth-round win over Huddersfield through illness and United manager Jose Mourinho is unsure whether he will feature against Sevilla.Asked whether Pogba had a serious problem, Mourinho replied: “I don’t know and, honestly, I don’t care.”United is a distant second in the Premier League, 16 points behind Manchester City. Mourinho’s team has been inconsistent in recent weeks, winning two and losing two of its last four games in all competitions.Sevilla, fifth in its domestic league, has won three matches in a row and is hoping to have Ever Banega and Luis Muriel back after injury.SHAKHTAR-ROMAAfter a difficult run domestically, Roma has turned things around with three straight wins.Turkish winger Cengiz Under scored his fourth goal in three matches to help the team to a 2-0 victory at Udinese on Saturday that left Roma in third place, two points ahead of Inter Milan.“We’ve got to make the most of the fact they’ve had a winter break and might not be match fit,” Roma coach Eusebio Di Francesco said of Ukraine’s Shakhtar. LAST WEEKThe first-leg matches played last week saw defending champion Real Madrid beat Paris Saint Germain 3-1 and Liverpool crush Porto 5-0.Manchester City cruised to a 4-0 win at Basel while Tottenham retrieved an early two-goal deficit to draw 2-2 at Juventus. Trending Articles PLAY LIST 00:50Trending Articles00:50Trending Articles00:59Sports venues to be ready in time for SEA Games01:29Police teams find crossbows, bows in HK university01:35Panelo suggests discounted SEA Games tickets for students02:49Robredo: True leaders perform well despite having ‘uninspiring’ boss02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City Don’t miss out on the latest news and information. MOST READ LATEST STORIES Slow and steady hope for near-extinct Bangladesh tortoises Cesc Fabregas will also be desperate to play against his former team but may have to settle for a spot on the bench.Barca has lost only once in 38 matches this season since falling in the Spanish Super Cup to Real Madrid in August. It has a seven-point lead at the top of La Liga and has reached the final of the Copa del Rey.Messi is having another stellar campaign, scoring 27 times in all competitions, and he helped set up two goals in Saturday’s 2-0 win at Eibar.Philippe Coutinho is ineligible for Barca following his move from Liverpool.Here’s a closer look at the week’s other games:BAYERN-BESIKTASBayern coach Jupp Heynckes must decide which of his in-form attacking midfielders should play.Arjen Robben shone for the runaway Bundesliga leader in Saturday’s 2-1 win at Wolfsburg but Thomas Mueller could take his place on the right, with James Rodriguez coming in to partner Arturo Vidal, having been rested at the weekend.The victory means Heynckes has won 21 out of 22 games since returning as coach.Besiktas surprised many by advancing from a group featuring Porto, Monaco and Leipzig. AFP official booed out of forum Globe Business launches leading cloud-enabled and hardware-agnostic conferencing platform in PH 2 ‘newbie’ drug pushers fall in Lucena sting Bayern Munich hosts Besiktas in Tuesday’s other game while the following day sees Manchester United traveling to Sevilla, and Shakhtar Donetsk playing host to Roma.Two weeks ago, the prospect of a Chelsea win over Barca would have been unthinkable after Conte’s men had slumped to successive defeats by two of the Premier League’s lesser lights.The London club was still smarting from a 3-0 home loss against Bournemouth when it traveled to Watford and succumbed to an embarrassing 4-1 reverse.Chelsea has got back on track since then, though, easing past West Bromwich Albion 3-0 in the league last Monday before swatting aside second-tier Hull 4-0 in the FA Cup four days later.Conte has several selection dilemmas. He must choose between captain Gary Cahill and Antonio Rudiger for a place at the back, and between Alvaro Morata and Olivier Giroud up front.ADVERTISEMENT Team Steph, Team LeBron tip off NBA All-Star Game “I hope we maintain this tradition but we are speaking about a fantastic player,” Conte said ahead of the last-16, first-leg Champions League game. “The most important thing is the present.“We must have great respect but at the same time we must be excited to play this type of game and take on this type of challenge. It won’t be easy because we know very well this player, we are talking about one of the best in the world.”FEATURED STORIESSPORTSWATCH: Drones light up sky in final leg of SEA Games torch runSPORTSLillard, Anthony lead Blazers over ThunderSPORTSMalditas save PH from shutoutThe teams have produced some epic games in the past although they have not met in the Champions League since Chelsea pulled off a remarkable backs-to-the-wall semifinal victory over Barcelona on the way to winning the trophy in 2012.Messi missed a penalty in the second leg at the Nou Camp as the London club overcame the first-half dismissal of captain John Terry, and a 2-0 deficit, to draw the game 2-2 and secure an unforgettable 3-2 aggregate win. John Lloyd Cruz a dashing guest at Vhong Navarro’s wedding Brace for potentially devastating typhoon approaching PH – NDRRMC View comments
India Today Mind Rocks, the country’s eagerly awaited youth event, is coming to rock Delhiites once again on September 6 at Siri Fort Auditorium, Delhi. Mind Rocks is an event designed especially for the youth. It is a forum that allows bright young minds to meet and interact with their favourite icons in an open two-way conversation.This event provides an interactive platform where youngsters get a chance to meet and interact with the country’s biggest icons from all fields. It’s a festival that celebrates ideas, music and art by recognising the best in the field and also giving youth a stage to create, perform and engage.The ninth Mind Rocks will be held at Delhi’s Siri Fort Auditorium on September 6. Like previous years, this edition too will see top politicians, businesspersons, sports personalities and film stars sharing their success stories and discussing issues of national interest with the audience.The Mind Rocks will be attended by actress Deepika Padukone, singers Yo Yo Honey Singh and Rabbi Shergill, comedian-cum-politician Bhagwant Mann, actor-turned-politician Chirag Paswan, cricketers Jhulan Goswami and Mithali Raj, Olympic medallist Rajyavardhan Singh Rathore, footballer Gouramangi Singh and many more.The finale of the event will be a live performance by Sufi rocker Rabbi Shergill, who shot to fame with soulful numbers such as Bulla Ki Jana and Challa. The past eight summits have been very successful with the participation of celebrities like Ajay Devgan, Katrina Kaif, Ranbir Kapoor, Ranveer Singh, Priyanka Chopra, Dhanush, Shruti Haasan, Sonam Kapoor, Mary Kom and Nandan Nilekani etc.advertisementYoungsters between the age of 18 and 32 can register at www.indiatodaymindrocks.com
Trump tells impeachment jokes at annual turkey pardon event View comments A meeting with rival Manny Pacquiao is a possibility, according to the report. Google Philippines names new country director Wintry storm delivers US travel woes before Thanksgiving Filipino athletes get grand send-off ahead of SEA Games PLAY LIST 01:27Filipino athletes get grand send-off ahead of SEA Games00:59Sports venues to be ready in time for SEA Games00:44Manny Pacquiao on Floyd Mayweather: Let him enjoy retirement02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City01:07Trump talks impeachment while meeting NCAA athletes02:49World-class track facilities installed at NCC for SEA Games02:11Trump awards medals to Jon Voight, Alison Krauss Panelo: Duterte ‘angry’ with SEA Games hosting hassles LATEST STORIES FILE – Floyd Mayweather Jr. stands in the ring before Errol Spence Jr takes on Mikey Garcia in an IBF World Welterweight Championship bout at AT&T Stadium on March 16, 2019 in Arlington, Texas. Tom Pennington/Getty Images/AFPMANILA, Philippines—Floyd Mayweather Jr. is back in the Philippines.As per ABS-CBN report, Mayweather’s private jet arrived at a private hangar at 3:30 am Sunday. He stayed in Manila for less than five hours since he flew straight to Boracay at 7 am.ADVERTISEMENT READ: WATCH: Manny Pacquiao gets visit from Floyd Mayweather in lockerThe two faced each other in 2015 and their mega fight was dubbed as “The Fight of the Century” after nearly a decade of verbal rivalry pitted the generation’s best fighters against each other.Mayweather won the fight via unanimous decision and the two have since kept running into each other in public places.READ: Money well spent: Mayweather’s retirement tour makes stop in El Nido Pacquiao and Mayweather, who both had their respective entourage with them, bumped into each other in a Japanese nightclub back in January.ADVERTISEMENT Colombia protesters vow new strike after talks hit snag Don’t miss out on the latest news and information. The two also met in an NBA game where Mayweather was sitting courtside and Pacquiao greeted home from behind.Mayweather also flew to the country last year, taking a quick vacation in El Nido.Sports Related Videospowered by AdSparcRead Next MOST READ Cayetano: Senate, Drilon to be blamed for SEA Games mess Bloomberg: US would benefit from more, not fewer, immigrants Private companies step in to help SEA Games hosting Amid PBA All-star excitement, Louie Alas preoccupied with playoffs