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Transportation Science

New Speed Record Set For Wind-Powered Vehicles 138

Posted by Soulskill
from the gone-with-the-wind dept.
Hugh Pickens writes "Richard Jenkins reached 126.1mph in his Greenbird car on the dry plains of Ivanpah Lake in Nevada, setting a new world land speed record for a wind-powered vehicle. 'It's great; it's one of those things that you spend so long trying to do and when it actually happens, it's almost too easy,' says Jenkins. The Greenbird is a carbon fiber composite vehicle that uses wind (and nothing else) for power. The designers describe it as a 'very high performance sailboat,' but one that uses a solid wing, rather than a sail, to generate movement. Due to the shape of the craft, especially at such high speeds, the wings also provide lift; a useful trait for an aircraft, but very hazardous for a car. To compensate for this, the designers have added small wings to 'stick' the car to the ground, in the same way Formula 1 cars do. 'Greenbird weighs 600kg when it's standing still,' says Jenkins. 'But at speed, the effect of the wings make her weigh just over a ton.' Jenkins has also built a wind-powered craft that travels on ice, rather than land. 'Now that we've broken the record, I'm going back on to the ice craft. There's still some debate as to whether traveling on ice or land will be faster.'"
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New Speed Record Set For Wind-Powered Vehicles

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  • Obviously, they've never seen Aunt Flo's old Desoto with the busted crankshaft flying down the street during hurricane season ...
  • Crap (Score:3, Funny)

    by conureman (748753) on Saturday March 28, 2009 @09:34AM (#27369711)

    I hate breaking out the calculator to compare 600kg to a ton. Relative increase, I guess.

    • Re:Crap (Score:4, Informative)

      by matt4077 (581118) on Saturday March 28, 2009 @09:39AM (#27369729) Homepage
      1 ton = 1000kg, welcome to the metric system.
      • Re:Crap (Score:5, Funny)

        by MightyYar (622222) on Saturday March 28, 2009 @10:07AM (#27369837)

        Wait, so what's a megagram? Or is that 1024kg?

        • Re: (Score:2, Informative)

          by Ragzouken (943900)
          A megagram is also 1000kg, of course.
          • Re:Crap (Score:4, Informative)

            by MightyYar (622222) on Saturday March 28, 2009 @10:26AM (#27369935)

            I should have put a smiley :)

            But I do live in the US and so I really wonder why people use "ton" in supposedly metric-standardized countries? I mean, I know that 1000kg is sort-of close to the old 2000lbs, but it is really ambiguous and there is the perfectly good Mega. At the very least, it should be spelled "tonne", right?

            • by Ragzouken (943900)
              Oh right. I've always wondered why we don't use Mega, too. I guess it's a relic of all the people who grew up using imperial measurements trying to connect the two. I was not aware that the different spellings of tonne had significance until now. Ton is already ambiguous (long/short) without metric tonnes though.
            • Re: (Score:2, Informative)

              by Anonymous Coward

              A ton (known as a "long ton" in the US) is 2240lb i.e. 1016kg.
              In Commonwealth countries, to make things easier to calculate, a ton is now generally taken as 1000kg.
              In America, to make things easier to calculate, a ton is now generally taken as 2000lb i.e. 907kg.

              The spelling is now largely irrelevant since nobody really remembers the old system that well. All official or scientific measurements are in kilograms anyway, ton and tonne are both just colloquial, it never needs to be precisely disambiguated in th

        • Re: (Score:3, Funny)

          by eltaco (1311561)
          You're thinking of the mebigram :-)
          http://en.wikipedia.org/wiki/Mebibyte [wikipedia.org]
      • Re: (Score:3, Informative)

        1 ton = 1000kg, welcome to the metric system.

        Not so fast. Do you mean a British ton [wikipedia.org], US ton [wikipedia.org], or metric ton(ne)? [wikipedia.org] And, for more confusion, see that there is also a French ton [st-and.ac.uk].

        Okay. I should stop being facetious and get my 7 hours of sleep (relative to current Earth's rotation period - has to be said, because it is slowing down).

      • s/ton/tonne/; # makes it right with the story.

        "Tonne" is, I believe, always metric: 1000 kg (aprox 2,200 lb, or 1.1 ton (or 1.0 long ton).

        This is almost the weight of half a cord of seasoned oak firewood, or half a cord of green fir. Which has only a chewbackan meaning in this context. But it does leaven the pedantry a bit.

        Need more coffee...

    • Re: (Score:3, Informative)

      by conureman (748753)

      What I really hate is when TFA is misquoted in the summary, now I see that Jenkins said "tonne" which IS metric. D-oh!

    • Re:Crap (Score:5, Interesting)

      by tick-tock-atona (1145909) on Saturday March 28, 2009 @10:36AM (#27369997)
      Yeah, well I hate breaking out the calculator (or worse, actually reading TFA) to convert 126.1 mph to something non-archaic. (202.9 km/h)

      From wikipedia: "The name statute mile originates from a statute of the Parliament of England in 1592 during the reign of Elizabeth I. This defined the statute mile as 5,280 ft or 1,760 yards; or 63,360 inches. Both statute and international miles are divided into eight furlongs. In turn a furlong is ten chains; a chain is 22 yards and a yard is three feet, making up 5,280 ft."

      Seriously, WTF?
      • Re:Crap (Score:5, Informative)

        by zippthorne (748122) on Saturday March 28, 2009 @10:54AM (#27370071) Journal

        It's probably for dividing up plots and things. It's nice to be able to evenly divide things into other things. Without the "funny measurements" you end up with lots of fractions, which were much less easy to deal with in the days when a calculator was a person, and most normal people were lucky if they could read.

        Note also that an acre is 10 square chains, and 10 acres is a square furlong.

        What is a mile? It's a least-common-multiple(ish) of several smaller measurements which happens to be a convenient size for people traveling on foot. The km is also a convenient size for foot travel, but you can only divide it by 2s and 5s without resorting to fractions.

        • Re: (Score:3, Informative)

          by T Murphy (1054674)

          What is a mile?

          The word "mile" comes from mille, latin for thousand (just like the milli- prefix). A mile is 1000 paces of the Roman legions (a pace is 2 steps). At least that is the basis for the general distance- the exact amount depended on who decided to define what exactly it meant (such as the English defining it as the above post points out).

        • by Fumus (1258966)
          That's why he said "non-archaic". Now we're past people unable to read, and dividing into fractions is more convenient than memorising ten different measurement units.
        • by evilviper (135110)

          It's nice to be able to evenly divide things into other things.

          No! Everything must be multiples of ten!

          Long live METRIC TIME!

          "At the tone, the time will be 73 after 95... "
          "BEEP"

          Then, with time sorted out, we can start tackling the metric calendar... 10 months, with 100 days (10 weeks).

          Sure, you'll have fewer birthdays in your lifetime, but its well worth the benefits of a 1,000-days per year calendar.

      • by rschwa (89030)

        Get over it.

      • by Gospodin (547743)

        Actually, 5280 feet is very easy to calculate with - it's evenly divisible by all sorts of things. 5280 = 2^5 x 3 x 5 x 11

        If only they'd picked 4,620 feet, we'd really be in the pink. 4620 = 2^2 x 3 x 5 x 7 x 11.

  • Greenbird weighs 600kg when it's standing still,' says Jenkins. 'But at speed, the effect of the wings make her weigh just over a ton.'

    I doubt they're going fast enough for relativistic effects to increase their effective mass by 400 kg.

    • Re: (Score:3, Informative)

      by Goaway (82658)

      Weight and mass are different things. Their usage is correct.

      • Re:Near light speed? (Score:5, Informative)

        by tomhudson (43916) <barbara...hudson@@@barbara-hudson...com> on Saturday March 28, 2009 @10:11AM (#27369853) Journal

        Weight and mass are different things. Their usage is correct.

        Their usage is dead wrong. Weight is the effect of gravity on mass. The vehicle doesn't "weigh" more at speed - the effect of gravity on it hasn't changed. It just generates a down-force from the wing. To say that it weighs more is about as accurate as saying your weight changes as you jump up and down on a scale, or that an airplane weighs less than nothing when it's flying.

        Since energy can be converted to mass, they would have to be going at a large percentage of c to actually "weigh" more.

        • Re: (Score:3, Informative)

          by Tweenk (1274968)

          Since energy can be converted to mass, they would have to be going at a large percentage of c to actually "weigh" more.

          That's a non sequitur. Fast moving bodies do not have a higher "effective mass" because some of the energy is converted into mass. It's just an interpretation of the fact that as you approach c it takes more and more energy to accelerate. Another interpretation is that the mass is constant and the momentum does not depend linearly on velocity, but approaches infinity as the velocity approaches c.

        • by smoker2 (750216)
          They never mentioned gravity. They said the down force makes it weigh more. Weight is measured with scales, and under sufficient down force the scales will read a higher value, thereby *weighing* more. The mass hasn't changed, gravity hasn't changed but the scales aren't lying. Large trucks have multiple axles to distribute the weight. Each axle measures less when *weighed* than if all the weight was on one axle. It is pedantic to claim the item doesn't effectively *weigh* less (or more). An items mass neve
          • by tomhudson (43916)
            Bullshit. The summary itself says that the downforce is generated by wings fixeed to the craft. The craft's weight does not change, you're just adding the force generated by the down-wing. Put a scale under the down-wing, get the 400 kg of force generated there, or are you going to argue that the wing now weighs 400 kg? Think of it -there's a difference between weight and force. We don't say a 10-pound bag of sugar has a force of 10 pounds, we say it has a weight of 10 pounds - if we throw it off a 10-stor
            • Re: (Score:3, Insightful)

              by TheLink (130905)
              In practice people will hardly ever use your POV that weight is solely the effect of gravity on mass, since it's not that useful.

              For most people, weight means "apparent weight". The force that a weighing scale (theoretical or otherwise) would measure if you could put the object on it.

              Which in many circumstances will be something like:

              mass * acceleration due to gravity - bouyancy due to fluid/air the object is in - the force due to the earth spinning + "other stuff".

              "other stuff" could include downforce.

              This
            • by fbjon (692006)
              Hold it.

              We all know the craft's mass does not change. The weight also does not change, if weight is defined as the total gravity force acting between the object and the Earth on average. Its apparent weight does increase however, where apparent weight is the total force pushing it towards the ground. "Weight" already contains far too many assumptions to be anything but a pretty nebulous measurement under any circumstance. Thus, in context, saying that the craft's weight increases is perfectly logical.
              • by tomhudson (43916)
                No, because we know that the force of gravity on the object doesn't change, and that the extra force is from the spoilers giving down-thrust. Now, if we didn't know that this down-thrust existed, and were just presented with two measurements (say from on-board sensors) that showed that the total load on the tires, for example, had changed, we might assume that someone just loaded several passengers into the vehicle, so that its' overall weight was more - but, lacking the missing information, we'd be wrong.
        • by Goaway (82658)

          Their usage is dead wrong. Weight is the effect of gravity on mass.

          This has been pointed out already, but bears repeating: That is not so. Weight is what a scale measures. Weight is quite literally the value you get when you weigh something.

          • by tomhudson (43916)

            Weight is what a scale measures. Weight is quite literally the value you get when you weigh something.

            So if I stand on a scale, but I'm also lifting up some of my weight on the doorframe, I suddenly weigh less? I don't think so, Clyde.

            People would quite accurately point out that I was cheating, that my "weight" did not change.

            Ditto with the claim that the vehicle gains 400 pounds of weight at speed - it gets additional down-force. Force != weight, or in this case, downforce != weight. Get over it. If

            • You really are a tiresome pedant. Let it go already.

              • by tomhudson (43916)

                You really are a tiresome pedant. Let it go already.

                Seems you can't take your own advice ... :-)

                Look, the article is wrong, and it perpetuates a common misunderstanding, one that, oddly enough, seems to be more common today than it was a few decades ago. This is probably more due to the dumbing down of the school curriculum, and people embracing the "don't wanna know" mind-set - the same mind-set, btw, that gives us creationists, Intelligent Design, "dinosaurs walked with humans," "houses never go down

            • by Goaway (82658)

              So if I stand on a scale, but I'm also lifting up some of my weight on the doorframe, I suddenly weigh less? I don't think so, Clyde.

              People would quite accurately point out that I was cheating, that my "weight" did not change.

              Yes, you would weigh less. However, when people weigh themselves, they are actually interested in their mass and not their weight, even though casual English is not exact about the usage there. That is why people would point out that you are cheating - you are ruining the approximation of mass as weight.

      • Re:Near light speed? (Score:5, Informative)

        by TheRaven64 (641858) on Saturday March 28, 2009 @10:21AM (#27369897) Journal

        Not quite. The downward force when it is stationary is 600gN, the downward force when it is moving is 1000gN. The downward force due to gravity, also known as the weight, in both cases is 600gN. The mass in both cases is 600Kg. Neither the weight, not the mass, change. The mass could only change as a result of things being added to or removed from the vehicle, or as the result of relativistic effects (which are present at the recorded speed, but not significant enough to be measured). The weight could change if the mass changed, or if the vehicle climbed far enough from the centre of the Earth for the inverse-square attraction to be reduced (again, this is unlikely to happen unless it raced up a steep mountain; g varies a bit, but not enough to be worth bothering about, over the surface of the Earth). The downward force can change for a wide variety of reasons, but in this case due to a pressure differential caused by air moving more quickly over the underside of the stabilisers.

        Note: In this post, g is used as little-g, the acceleration due to gravity on the surface of Earth, while g is the SI unit gram. This is not quite standard notation; they should both be represented by the same symbol, which is just plain confusing.

        • Damn dude.

          They used weight to describe a force, which puts them lightyears worth of miles ahead of every other tech-writer that makes it into the popular press.

          • by conureman (748753)

            AFAIK downforce is a very common term in F1 racing, which was mentioned early and often in TFA. On this planet the Greenbird weighs about 600kg. At any speed.

        • Re: (Score:2, Insightful)

          by TheLink (130905)
          The "weight = m * g" definition is not very useful.

          The only use for that definition I've had is in high school physics exams.

          The more useful definition is weight = "apparent weight".

          Where weight = the actual force the object would exert on the surface it's on.

          And that is not m * g.

          It's m * g + downforce - bouyancy - force due to the earth spinning, and all sorts of other stuff.
        • by T Murphy (1054674)
          gg?
        • Parent post almost has it right. And is close enough for nearly any high school or undergraduate work.

          There is a difference between weight and mass. Mass is intrinsic to the object being measured; weight has to do with the forces acting upon the object, which is often just the force of gravity, but sometimes involves other forces. And that's the part that parent post misses. Weight has always been a matter of human perception, and most especially of the human capacity to imagine a perception that has not

    • Funny, but doesn't the mass decrease due to relativistic effects?

      • Nevermind!

      • by tomhudson (43916)

        Funny, but doesn't the mass decrease due to relativistic effects?

        (obligatory spaceballs references)

        It depends - did they go plaid yet?

        I'm still combing the desert looking for the answer to that one, and I ain't found shit yet!

        That will be answered in Spaceballs: The Lost Sequel - The Search For More Weight.

        Just use the schwartz to get this statue off my PAW!!!! I don't give a shit about mass, all I know is it weights a fr****ing ton!!!

        (closing scene) Related? To spaceballs? Oh shit, there goes the n

    • by fprintf (82740)

      It is only a matter of time before the record is broken again, both for Class C (as the links says, probably soon to be held by this boat) and for overall, currently held by a kiteboarder. The difference between what happens on water and on land is really dramatic. The fastest boats are remarkably slower than the fastest cars.

      BTW, it wasn't *particularly* windy during the record breaking attempts. Too much wind usually means gusty conditions and overpowering. What they needed was the right wind direction re

      • I'm not a physicist, so there's a lot I don't understand. For something to go over 100mph powered only by wind, wouln't the wind itself have to be over 100mph as well?

        How do you go faster than the force that is propelling you?

  • The Ice Schooner (Score:3, Interesting)

    by Doc Ruby (173196) on Saturday March 28, 2009 @10:23AM (#27369917) Homepage Journal

    This craft reminds me of the early Michael Moorcock SF story The Ice Schooner [geocities.com]:

    Although part of the general repackaging of Moorcock's fantasy output around the Eternal Champion theme, The Ice Schooner is not really that closely linked to the other novels. Having a hero and a quest is not really enough; there are few novels in the genre by any author which would share these common elements.

    The much revised novel is set in a future Ice Age, so severe that oceans of ice cover almost the entire surface of the Earth. On these frozen wastes sail great ship-like wind powered sledges, hunting the land whales evolved from the sea creatures of our own time. Konrad Arflane is captain of such a vessel fallen on hard times until he rescues a dying man out on the remote ice. He turns out to be the ruler of an important city, but more relevantly to the plot, he gives Arflane a quest, to find the fabled lost city of New York, a vision, in his daughter, and a ship, a great ice schooner, to captain.

    • Much revised? What, are there multiple versions of the book?

      And FWIW, whoever wrote that isn't too clued into the eternal champion theme - among other things, New York was clearly Tanelorn, definitely making The Ice Schooner yet another version of the eternal champion theme.

      • by Doc Ruby (173196)

        If you click the link, you see that it was indeed revised.

        And I think their description was apt. TIS is indeed not that closely linked to the Eternal Champion cycle, except in some packaging, as that review says. I read most of all the other incarnation books (including Jerry Cornelius), and I agree with that description.

  • "Richaaaaaaaaaaaaaaard!"

  • wow; impressive (Score:4, Interesting)

    by WindBourne (631190) on Saturday March 28, 2009 @10:48AM (#27370049) Journal
    growing up, we used to race a DN class iceboat. IceMice could do over 70 mph in a 30 mph wind. This is another 50 mph faster. Tip the craft on dirt, and you will know it.
    • by clockt (882520)
      From the greenbird web site:

      The Greenbird is two vehicles: a land craft and an ice craft, powered only by the wind. ... The project's aim was to break both the land and ice world speed records. On March 26, 2009, the Ecotricity Greenbird set a new world land speed record for wind powered vehicles of 126.1 mph. The team hopes to both better that new record, and continue to work toward breaking the ice record in Winter 2009/10.

      Should be interesting to see how it goes on ice. Watch out, IceMice. The publici

      • I was just checking up on some of that. Lake Geneva (~15 miles north of where I grew up; wonder lake, ill) now has something called the skeeter that does 100 mph. I suspect that this vehicle may blow it away.

        as to the vertical wind turbines, I have always been amazed that they those did not catch on in the city. Struck me as the way to go for places like Chicago (not called the windy city for no reason) or Milwaukee (Summer fest is one of the best things about that town).
        • by wfstanle (1188751)

          "Struck me as the way to go for places like Chicago (not called the windy city for no reason)"

          Actually, Chicago got the moniker "the windy city" not for the weather. It was to describe its politics.

    • I had an Arrow class iceboat and regularly got over 70 mph. These speeds are pedestrian for iceboats. The DN class and Arrow class really don't take aerodynamics very far having completely open cockpits. Now the Skeeter class takes aerodynamics quite seriously having an almost enclosed cockpit and many other aerodynamic features. Its drag is quite low.

      Actually, an iceboat was clocked at 143 mph and this was many years ago. The potential for impressive speeds on ice is pretty big.

      For more information go

      • Yeah, the skeeters came out after I was done. Interestingly, was developed by a guy that we used to race against on the c-scows (buddy melges who also owns the melges boat works; also a gold medal winner). Never went on that, but, I did occasionally go on a Nite (developed by another guy that we used to sail scows against). Never cared for that boat. If a nite tipped, I always felt like the mast would be tore off(or just have a stay be snapped), and half of your body was exposed. At least with the DN, you s
        • by wfstanle (1188751)

          Yes the sport has a reputation for some spectacular accidents. Where I sailed, on Lake St. Claire (Michigan), there was this BIG old iceboat called "Buckaroo". It was so big that it got away with jumping small cracks in the ice. (A sure recipe for disaster.) The end for it was the skipper got complacent and tried to jump a crack that was too large. The result was predictable... 60 foot iceboat to matchsticks in one step. There were 4 people on it at the time and although there were no fatalities, the

  • by tjstork (137384) <todd...bandrowsky@@@gmail...com> on Saturday March 28, 2009 @10:59AM (#27370109) Homepage Journal
    Interesting, but totally useless for cars. The wing is way too tall for traffic. But for ships, its a different story. Question is: If it takes a 40 foot high wing to move a 1 ton car, how big of a wing would you need to move a 50,000 ton container ship? The heaviest sailing vessel yet constructed is the Star Clipper: Star Clipper [starclippers.com], which is 5000 tons and traditionally rigged with about 50,000 square feet of sail handled by 20 crewman.
    • Re: (Score:3, Interesting)

      by drinkypoo (153816)

      I also wonder if a rigid wing would work well on smaller sailboats. It might help more people use sail for travel where they now use motor launches. I don't think it's going to take over waterskiing any time soon, but that would be cool too.

      • Re: (Score:2, Interesting)

        by Yacoby (1295064)

        A rigid wing would be lethal in a harbor, as you can't take it down easily, and if the wind changed, suddenly you have a boat that is attempting to move and a boom swinging about.

        Another large bonus of a fabric sail is that it will flap when my sail isn't set correctly or when I am sailing to much into the wind. A rigid sail wouldn't.

        Fabric is lighter, and I assure you, the last thing you want is a lot of weight high up. It makes the boat a lot more likely to roll, and you already have a large surface area

        • by drinkypoo (153816)

          A rigid wing would be lethal in a harbor, as you can't take it down easily, and if the wind changed, suddenly you have a boat that is attempting to move and a boom swinging about.

          You're assuming that it can't be opened to let wind through or something.

          Another large bonus of a fabric sail is that it will flap when my sail isn't set correctly or when I am sailing to much into the wind. A rigid sail wouldn't.

          But strain gauges can let you know what's going on.

          Fabric is lighter, and I assure you, the last thing you want is a lot of weight high up. It makes the boat a lot more likely to roll, and you already have a large surface area that the wind can push.

          I hear you on the weight thing, I suppose it would only work for heavily keeled vessels (for their size anyway.)

          • by Yacoby (1295064)

            You're assuming that it can't be opened to let wind through or something.

            You still have a large flat object longer than the width of the boat that will always orientate itself to the wind. A huge weather vane in effect. Take a look at a harbor and see how boats are tied up. Right next to each other. You are not going to make many friends if you keep smashing the adjacent boats shroud.

        • A rigid wing would be lethal in a harbor

          http://en.wikipedia.org/wiki/Turbosail [wikipedia.org]
          The Cousteau folks seem to have survived it.

    • by Mad_Rain (674268)

      Question is: If it takes a 40 foot high wing to move a 1 ton car, how big of a wing would you need to move a 50,000 ton container ship?

      I think a better question is: Why do you need to move a ship that big on sail power alone? While it would be cool to do so, using wind power in conjunction with conventional engines improves efficiency reducing fuel consumption between 10 and 35 percent [cnet.com], which is a good start.

    • by jeti (105266)

      A 160-square meter kite sail is expected to reduce the diesel consumption of a 10,000-tonne ship by 20%.
      http://www.reuters.com/article/inDepthNews/idUSL1548100520071217?sp=true [reuters.com]

    • The exact same size of wing...

      After all, you said nothing about the speed. Wait long enough and the ship itself will move in the wind.

  • by JoshuaZ (1134087) on Saturday March 28, 2009 @11:18AM (#27370201) Homepage
    The physics that allows one to sail faster than the wind aren't completely obvious. Terence Tao wrote a very good explanation of the basics http://terrytao.wordpress.com/2009/03/23/sailing-into-the-wind-or-faster-than-the-wind/ [wordpress.com] where he also shows a nice theoretical construction that allows one to accelerate to any speedy (assuming that the universe is Newtonian).
    • he also shows a nice theoretical construction that allows one to accelerate to any speedy (assuming that the universe is Newtonian).

      Even to a Gonzales?

  • Two runs? (Score:5, Funny)

    by srussia (884021) on Saturday March 28, 2009 @11:26AM (#27370239)
    Did they take the average of two timed runs in opposite directions in order to compensate for, you know... wind speed?
  • Anyone else thinking how much this car blows??
    zing!
  • There's still some debate as to whether traveling on ice or land will be faster.

    I think if it weighs a ton, I could probably answer this question...

  • Here's a link [youtube.com] to the youtube video of the actual run. It's quite interesting to see the difference between the ice version and the land speed record version of the craft. Apparently there are some incredible downforces being generated as well.
  • Such a great achievement. The boundaries are pushed in so many areas such that there is little left one can push as an individual and get the "fastest" mark.

    Most of Slashdot is discussing the relativistic merits of the added mass !!!

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