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A Liquid That Turns Solid When Heated 450

Posted by timothy
from the ye-canna-break-th'-laws-o-physics dept.
Roland Piquepaille writes "There are some sure things in life, such as death and taxes. When you are heating a solid, you expect it will melt and when you're boiling water, you're pretty certain that it will turn into vapor. But what about a liquid that becomes solid when it's heated? Of course, it has already been done, for example in the chemical process of polymerization. But now, PhysicsWeb writes that a team of French physicists has discovered a law-breaking liquid that defies the rules. When you heat it between 45 and 75C, it becomes solid. But the process is fully reversible, and this is a world's premiere. When you decrease the temperature, this solid melts and turns again into a liquid. I'm not sure of the implications of such a phenomenon, but it's fascinating. Read more for essential details."
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A Liquid That Turns Solid When Heated

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  • by lesterchakyn (235922) <(cesar.negrete) (at) (gmail.com)> on Saturday September 25, 2004 @02:33PM (#10349690)
    This is one of the things that makes you think if everything is as you know...

    The Matrix anyone?
  • what it says (Score:5, Insightful)

    by pbranes (565105) on Saturday September 25, 2004 @02:33PM (#10349694)
    What it says:

    Plazanet and colleagues prepared a liquid solution containing a-cyclodextrine (alpha-CD), water and 4-methylpyridine (4MP). Cyclodextrines are cyclic structures containing hydroxyl end groups that can form hydrogen bonds with either the 4MP or water molecules.

    What I see:

    And if you expect me to tell you how this discovery will modify our lives, you're going to be disappointed. I've not a slightest idea about it, even if I find fascinating that scientists always find new ways to break rules and shake our certitudes.

    • by afidel (530433)
      Failed freshmen chem did we?
    • Learn some chemistry. Hydrogen bonds [wikipedia.org] have a lot to do with the interesting properties of water (which is quite an odd chemical, by the way).
    • by Idarubicin (579475) <.moc.liamtoh. .ta. .teiuqslla.> on Sunday September 26, 2004 @01:11AM (#10353228) Journal
      What I see:

      And if you expect me to tell you how this discovery will modify our lives, you're going to be disappointed. I've not a slightest idea about it, even if I find fascinating that scientists always find new ways to break rules and shake our certitudes.

      What I see:

      I am a chemist that has discovered a class of mixtures with a very interesting and heretofor unobserved property. I have published information on how to prepare these mixtures--in a way, it is a solution looking for a problem. I expect that given a small group of engineers, a dozen or so different applications could be hashed out over their morning coffee. I am disappointed--but not surprised--that a Slashdot reader couldn't be bothered to use his imagination to come up with an application, preferring to instead complain that no ideas were spoon-fed in the brief PhysicsWeb note.

  • by Anonymous Coward on Saturday September 25, 2004 @02:34PM (#10349700)
    so what could the application of such a material be? a new breed of thermometers are on their way, i guarantee it.

    thermometers for the 21st century and beyond.
    • We've already got good thermometers. How would this magically be better?
    • by theAedileDecimus (728792) on Saturday September 25, 2004 @02:48PM (#10349798)
      I can just imagine it now...

      You go to Target to buy a 12-pack of "One-Time Use Thermometers."
      Instructions: "When the temperature is between 45 and 75 degrees celcius, the liquid inside turns to a solid, shattering the glass! That's all there is to it!"
    • by TWX (665546) on Saturday September 25, 2004 @03:04PM (#10349901)
      I think that my girlfriend is comprised of this stuff. She seems to suddenly turn frigid as soon as things heat up...
    • by gnalle (125916) on Saturday September 25, 2004 @03:37PM (#10350121)
      When the liquid melts, the heat of melting is taken from the vibrational energy, and thus the liquid is cooled by melting. I guess that this positive feedback mechanism would enable the liquid to melt fast whenever it is cooled below the melting point, and thus the new liquid should be very effective for cooling stuff very fast.

      To a physicist the phase diagram is interesting, because the solid/gel must have a larger entropy than the corresponding liquid. (Remember that you calculate equilibrium by minimizing the Gibbs energy G = H - TS).

      Anyway it has been known for many years that some triblock polymers form gels when heated, but perhaps the solid phase of this new liquid is "more solid". Perhaps the news is that the liquid has a larger enthalpy of melting. I don't know

    • by Weaselmancer (533834) on Saturday September 25, 2004 @03:40PM (#10350139)

      Shock absorbers. This stuff would make fantastic shock absorbers.

      Reinforcement for solid structures. Somebody already mentioned skyscrapers, but I'm also envisoning other more improbable structures, like hurricaine proof buildings. Wind blows, soften up the beams and let her bend a bit. Wind stops, stiffen the supports back up.

      Mecha. This has to be used in mecha. Beams that can bend a bit, be solid or fluid, would be excellent in 50 foot killer robots. You know it.

      Tank armour. Make it solid and when stuff hits, it breaks. Change temperature, and it melts. Change temp again and it becomes solid again, with no signs of previous damage. Regenerating armour.

  • by Anonymous Coward on Saturday September 25, 2004 @02:35PM (#10349707)
    In other news:
    Cookie dough batter turns to solid in oven when heated. (Yeah, yeah, it's not reversible...)
  • What?! (Score:5, Funny)

    by Anita Coney (648748) on Saturday September 25, 2004 @02:36PM (#10349713) Homepage
    No references to Ice nine?! I must be getting old.

  • by dat00ket (249468) on Saturday September 25, 2004 @02:37PM (#10349722) Homepage
    Fascinating stuff. This physics marvel of a liquid is a mixture of many separate elements... including milk, flour, eggs, sugar, and a pinch of salt.
  • The French have been freezing up when things get heated for years.
  • by Wizzy Wig (618399) on Saturday September 25, 2004 @02:39PM (#10349733)
    a bag of "Hot Cubes" to keep the coffee warm.
  • Assassins take note! (Score:4, Interesting)

    by Twisted Grind (815318) on Saturday September 25, 2004 @02:41PM (#10349745)
    The temperature at which it becomes a solid falls as the concentration of áCD increases.

    So...if you were to put this in someone's bloodstream with the right concentration, you could cause it to solidify once it reached standard body temperature...
    • The Sci Fi angle... (Score:2, Interesting)

      by Wizzy Wig (618399)
      Isn't this how "The Andromeda Strain" did it's dastardly work? Turning the blood into a solid crystaline polymer?
    • by EvilSporkMan (648878) on Saturday September 25, 2004 @02:55PM (#10349853)
      Putting it in someone's bloodstream would probably kill them ANYWAY - wouldn't cheaper poison be easier?
    • Some snake venom basically does that, although I'm pretty sure the reaction is entirely chemical independent of temperature.
    • There's a flaw in that logic: The human body would not be able to tolerate the 47 degree temperature that would signal the *beginning* of the hardening process.

      The human body is a toasty 37 degree celsius (98.6 degrees fahrenheit). To take it to 47 degrees (116 degrees) would likely kill the person long before the hardening of the substance would.

      Never mind the 75 (167) degrees...

      Methinks that this might have some value as reinforcement for ceramic moulds.

      Or... perhaps a form of cooking spray that wou
  • by Anonymous Coward on Saturday September 25, 2004 @02:41PM (#10349748)
    Hell has officially frozen over now.
  • Heat shield? (Score:5, Insightful)

    by BigZaphod (12942) on Saturday September 25, 2004 @02:41PM (#10349750) Homepage
    I don't know much about physics, but could something like this be used as a heat shield of some kind? Like, where the shield is basically considered turned off when it is in the liquid state. Then when it hits a certain overload temperature, it turns to a solid and thus blocks (some of) the heat exchange?
    • Re:Heat shield? (Score:5, Informative)

      by novakyu (636495) <novakyu@member.fsf.org> on Saturday September 25, 2004 @02:56PM (#10349857) Homepage
      I don't know much about physics, but could something like this be used as a heat shield of some kind? Like, where the shield is basically considered turned off when it is in the liquid state. Then when it hits a certain overload temperature, it turns to a solid and thus blocks (some of) the heat exchange?

      That would probably depend on the property of the solid that forms when the solution is heated (is it a good insulator? what are its structural properties?), but I can think of one related application: temperature-controlled switch.

      The solution is transparent to visible light, whereas the solid that forms is not. Since this process depends on the temperature and is reversible, it's very simple to design a circuit (using a LED and phototransistor or some sort of photo-detector) that works as temperature-dependent switch. From what the article says,

      The temperature at which it becomes a solid falls as the concentration of CD increases.

      it should be possible to tweak the turn-on temperature to a degree.

      But then, this is not anything new--as far as dependence on temperature goes, there are many other materials that are probably more reliable (the only thing novel about this would be that its dependence is backward.)

      Back to the topic, yeah, it can probably be used as heat shield in a limited capacity: i.e. if it turns out that the liquid is transparent to infrared radiation while the solid isn't, this can be used as natural temperature-controlled infrared radiation shield (but of course, it will still be subject to heating due to other methods, like...conduction via the solid itself, unless the resulting solid turns out to be similar to styroform).

      • Since this process depends on the temperature and is reversible, it's very simple to design a circuit (using a LED and phototransistor or some sort of photo-detector) that works as temperature-dependent switch

        It would be far simpler to exploit the temperature dependence of the LED or the transistor, or maybe an even more simple device that is made for temperature sensing.
    • Why are you assuming that the material's conductive properties change when it becomes solid? Do you know something about aCD and/or 4MP that the rest of us don't?
    • Re:Heat shield? (Score:3, Interesting)

      by glesga_kiss (596639)
      The interesting thing about that application is that the shield could reform when things cool down. If it were an ablative shield (takes damage), then you could potentially have it fix itself between uses.
    • Re:Heat shield? (Score:3, Informative)

      by dbIII (701233)

      I don't know much about physics, but could something like this be used as a heat shield of some kind?

      Good point, it takes a lot more energy to change phase (eg. ice to water, water to steam) than it does to simply heat a single phase material a few degrees. The phase change will consume energy before heating will occur again. That is the reason why ice water is at 0 celcius until you melt all of the ice, even if the pot it is in is at 100 celcius - you have to put enough energy in to complete the phase c

  • by garyisabusyguy (732330) on Saturday September 25, 2004 @02:44PM (#10349768)
    Why do I see a new line of sex toys being based on this?

    Or at least a splint that packs down small but that remains rigid when in contact with a warm body.

    Um.. Maybe that would apply to a sex toy ;)
  • You could make a neat security system will only work when "heated" and solid otherwise it wont let you in.
  • by ir0b0t (727703) * <(mjewell) (at) (openmissoula.org)> on Saturday September 25, 2004 @02:45PM (#10349779) Homepage Journal
    I think I've been drinking this stuff out of the coffee pot in my office for several years now.
  • by Hockney Twang (769594) on Saturday September 25, 2004 @02:47PM (#10349791)
    It's a solid at those temperatures, what is it at higher temps? Liquid again? Does it have two melting points? At what temp does it vaporize? Does it freeze at some point below the normal low-end melting point? At 0 degrees Kelvin, it's definitely a solid, somewhere above that, a liquid, then a solid again, then a liquid again, then a vapor? Maybe.
    • by dat00ket (249468) on Saturday September 25, 2004 @03:01PM (#10349884) Homepage
      "At 0 degrees Kelvin, it's definitely a solid"

      I wouldn't be too sure about that.

      Bose-Einstein Condensate [wikipedia.org]
      Superfluids [wikipedia.org]

      First rule of physics: When you're dealing with extremes, things get funky.

      • by DavidTC (10147) <slas45dxsvadiv.vadiv@NoSpam.neverbox.com> on Saturday September 25, 2004 @04:21PM (#10350397) Homepage
        At 0 degrees Kelvin, it's not anything. It's just, in theory, a bunch of suspended frozen stuff that's exactly where it was before you hit 0. It has no chemical properties, because there is no way to do any sort of chemical interaction with it.

        That's in theory, of couse, since you can't hit 0 degrees Kelvin.

        But assuming you mean 'near 0 Kelvin', like d00ket pointed out, things get really weird down there. Some substances don't appear to have freezing points, there is no state below 'liquid'...they just move slower and slower. And some freeze quite normally, then do another transition way down there where they move back to a liquid like substance.

        The substance in the article is interesting, but not completely amazing. Various 'states of matter' are just rules of thumb.

    • by iabervon (1971)
      It is not a uniform substance, but rather two chemicals dissolved in water. The article doesn't say specifically, but I'd guess at higher and lower temperatures, the chemicals come out of solution and/or undergo irreversible chemical changes. It's a bit like jello except with the gel and the solution behaviors backwards; freezing it or boiling it causes it to separate and behave normally.
  • Applications? (Score:2, Interesting)

    by Nordberg (218317)
    Get ready for the soon to be classic -cyclodextrine in the oilpan trick.
  • by bombastinator (812664) on Saturday September 25, 2004 @02:49PM (#10349802)
    I remember either Porsche or Volkswagen having a limited slip clutch that consisted of two perforated disks set next to each other in a container of special goo. If the wheels slipped it caused the disks to rotate at different speeds and the friction caused enough heat to turn the goo solid. I can't remember why they quit using it but it was more than a few years ago. I think it was going into their 4 wheel drive race cars. Just a memory though I got no hard data. Anyone know more about this?
    • by HenryKoren (735064) on Saturday September 25, 2004 @03:36PM (#10350111) Homepage
      You are refering to the All Wheel Drive system produced for the VW Audi Group by Haldex

      From Haldex [haldex-traction.com]:

      The unit can be viewed as a hydraulic pump in which the housing and an annular piston are connected to one shaft and a piston actuator is connected to the other.

      The two shafts are connected via the wet multi-plate clutch pack, normally unloaded and thus transferring no torque between the shafts.

      When both shafts are rotating at the same speed, there is no pumping action. When a speed difference occurs, the pumping starts immediately to generate oil flow. It is a piston pump, so there is a virtually instant reaction with no low-speed pumping loss.

      The oil flows to a clutch piston, compressing the clutch pack and braking the speed difference between the axles. The oil returns to the reservoir via a controllable valve, which adjusts the oil pressure and the force on the clutch package.

      Something tells me having hydralic fluid that turns solid when it gets hot wouldn't help a system like this :-)
    • by Afrosheen (42464) on Saturday September 25, 2004 @03:52PM (#10350199)
      You're talking about a standard 'wet' limited slip differential, or LSD. Wet LSD's have a viscous solution inside that, as the spider gears generate friction by spinning opposite directions, solidifies to unify power delivery from the driveshaft. An open differential allows wheels to spin at differing speeds, usually giving more power to the wheel that's spinning more freely. This is bad in racing. It's also bad for 4wd cars like the Subaru WRX or the Mitsubishi Evolution VIII. Both cars have LSD standard.

      The other type of LSD is a clutch-plate type. These can be adjusted for resistance to slippage by arranging the type and order of clutch plates in the LSD. A viscous LSD on the other hand is governed by the properties of the fluid, and is subject to failure under high loads (i.e. the liquid can only take so much friction before it breaks down and loses it's valuable properties). In general practice, for performance and cost, viscous LSD's are used, but for high performance, resilience, adjustability and durability, the clutch type LSD is preferable, but has a significantly higher cost.

      That's about all I know about LSD's.
  • by mike_lynn (463952) on Saturday September 25, 2004 @02:50PM (#10349808)
    Which law would this be? The one that says solids melt into liquids at higher temperatures? Oh wait, there is no such law - thanks to something called Sublimiation where solids go straight to a gas (like dry ice).

    This is not an example of a new found element with impossible thermal properties. This is an example of materials and molecular chemistry in action. This works because it follows the laws of physics.
    • by Bill, Shooter of Bul (629286) on Saturday September 25, 2004 @06:18PM (#10351131) Journal
      Every one at slashdot thinks they understand science because they think of themselves as geeks. I say it is not being a geek that makes you a scientist, but being a scientist makes you a geek. This story is a perfect example. Some material does something that we would not expect based upon our own observational experience, but since we "know science" it must violate all of our accepted scientific ideas. Its really funny if you don't take it serious. Seriously it must show that our educational system has doen such a poor job of explaining the basics of the scientific process and/or that we'd rather make fools of ourselves than admit that we don't know everything.
  • by Compuser (14899) on Saturday September 25, 2004 @02:51PM (#10349820)
    Reverse melting has been known for a long time.
    People have been studying vortex systems that
    do that. This is only new because it's a chemical
    compound (rather than say electrons) that does this.
    No physics breakthrough here. Maybe chemical
    engineering breakthrough but that's it.
  • Space shuttle? (Score:3, Interesting)

    by Bin_jammin (684517) <Binjammin@gmail.com> on Saturday September 25, 2004 @02:53PM (#10349832)
    I wonder if it would be possible to change the temperature at which it re-liquifies, and if it becomes harder or more dense at higher temperatures. Seems like if that were the case, it would make for a good tiling material for the skin of a space shuttle
  • by Mr2cents (323101) on Saturday September 25, 2004 @02:54PM (#10349838)
    I vote for a new "Roland Piquepaille" section, he should get a good amount of advertisement revenue from his daily submits, always with "read more" links just quoting the original story.
  • by Anonymous Writer (746272) on Saturday September 25, 2004 @02:54PM (#10349839)

    Plazanet and colleagues prepared a liquid solution containing ?-cyclodextrine (?CD), water and 4-methylpyridine (4MP).

    Is it edible?

  • by softspokenrevolution (644206) on Saturday September 25, 2004 @02:54PM (#10349845) Journal
    Damn you hydrogen bonding, damn you shaking up our worlds with your heat freezing solids.
  • by Duct Tape Pro (318982) on Saturday September 25, 2004 @02:55PM (#10349852) Homepage
    I sure hope it's non-conductive so I can put it as a coolant in my computer. Computer gets too hot, it turns solid and the computer "locks up". Ha!

    Seriously though, if this stuff interacts well with other substances (i.e. doesn't explode, melt, send it to another dimension) then it could feasibly have applications where it would solidify around objects once they got too hot, thereby stopping their motion. And since the article says you can adjust the solidifying (freezing?) point based on its concentration, it could be tailor-made for different devices. This probably won't happen though because I'm guessing this stuff is probably expensive to make and does who-knows-what to human tissue

  • ...that gives me hope for a room temperature superconductor. Heating liquids into solids? Hey! You never know!

  • by Billy the Mountain (225541) on Saturday September 25, 2004 @03:02PM (#10349890) Journal
    This article [newscientist.com] describes a similar material that is liquid below 20 C and solid above 32 C. Medical researchers hope to use it if they are able to perfect 3D printers that generate organs by spraying cells onto a substrate. The gel is used to reserve open spaces for blood vessels. Once the organ has been formed they cool it and the solid turns to liquid and runs out.

    BTM
  • by MrIcee (550834) on Saturday September 25, 2004 @03:03PM (#10349897) Homepage
    ...with my oven and fridge. I put some basic liquid ingredients into a pan, place the pan into my heated oven where, once properly forgotten, it turns into a solid.

    Placing the solid into my fridge, and again forgetting it for say, 2 or 3 weeks, reduces the solid back into a liquid.

    Though I havn't personally tried it, I'm fairly certain that if I were to return the liquid back to the oven, and again properly forget about it, that I would again get a solid.

  • Breaks the rules? (Score:4, Informative)

    by Epsillon (608775) on Saturday September 25, 2004 @03:04PM (#10349908) Homepage Journal
    The rules of freezing, melting and vaporising (yes, I missed out sublimation) are not broken here. Chemists have known for some time that certain reactions can both only take place at a certain range of temperatures and reverse outside that range. This stuff does not freeze. It simply undergoes a reaction which bonds two types of molecule together to form a cohesive structure. The "normal" rules still apply to both compounds, but the new compound has a higher freezing point. That the reaction to form the new compound is reversible is also nothing new.

    Analogy: Water freezes at 0 degrees Celsius, sodium chloride (salt) much higher at 804 Celsius. Add the two together to form an aqueous solution of sodium chloride and it lowers the freezing temperature, contrary to the properties of both substances. Heat it, and evaporate the water off and you end up with solid NaCl.

    Sorry, but this has been hyped beyond recognition.
    • Re:Breaks the rules? (Score:3, Informative)

      by Alsee (515537)
      This stuff does not freeze. It simply undergoes a reaction which bonds two types of molecule together to form a cohesive structure.

      In other words it freezes.

      And your boiling salt-water analogy is horrid. This is pure and reversible melting freezing process.

      It isn't a "scientific breakthrough" in that there is no new new physics understanding, however it is an entirely new material with entirely novel behaviour. Novel materials with novel behaviour is an opportunity for entirely novel engineering and ent
  • Astroturf Alert! (Score:4, Informative)

    by Gothmolly (148874) on Saturday September 25, 2004 @03:07PM (#10349921)
    Warning, this Roland fellow submits (and they get accepted!) stories all the time, which link to his personal blog site. All his posts have the same format. Stop feeding him page views!
  • by Goeland86 (741690) <goeland_86.yahoo@fr> on Saturday September 25, 2004 @03:12PM (#10349968)
    I remember reading somewhere about making a bullet proof suit for soldiers where the suit was in fact hollow and filled with a gel containing nanoparticles. This thing might help us make more efficient ones: when the bullet hits the gel, the pressure is going to make it increase in heat, isn't it? So as the bullet tries to penetrate, it's going to get harder and harder... thus absorbing a HUGE amount of energy. Once the bullet is fully stopped, the pressure disappears, the temperature goes back down to normal and you have a liquid armor again. One problem is keeping the liquid from spilling out of the holes the bullets make... But I'm quite confident that can be overcome with some brilliant imagination. Of course, the real problem is how breakable is the solid formed? Because if the bullet goes straight through the hard material, then there's not point. But I think that'd be one use of this...
  • by The Ultimate Fartkno (756456) on Saturday September 25, 2004 @03:12PM (#10349970)
    ...and all I can think is "Woohoo! Snowball fights in summertime!"

    Too much Calvin & Hobbes, I suppose.

  • by k98sven (324383) on Saturday September 25, 2004 @03:37PM (#10350123) Journal
    After reading the article (the actual publication, that is), here's an attempt at a summary.

    When you heat something, the entropy (disorder) of a system increases in importance. This is a law of thermodynamics.

    A gas has greater entropy than a liquid, both have greater entropy than a solid. Usually.

    Now, this substance turns solid when you heat it. -This means the solid phase has higher entropy than the liquid phase. That is unusual, but it doesn't violate any laws.

    How does it work? Well, it appear the alpha-cyclodextrin molecule has two conformations (shapes). In the low-temperature one, it hydrogen-bonds to itself. At higher temperatures, these bonds are broken. (this is what happens with ice-water-steam too)

    The funny thing about this substance, is that once these internal hydrogen bonds are broken, it allows the molecule to bind to other ones.. so while you break the "internal" hydrogen bonds, you give rise to a bunch of "external" molecular bonds, to other alpha-cyclodextrine molecules.

    This leads to the formation of a solid. (not actually a true solid, but rather a 'sol', a suspension of linked-together alpha-Cyclodextrin molecules in water) And this solid actually does have lower entropy than the liquid phase, due to the breaking of the internal hydrogen-bonds.

    No laws broken. Nothing 'impossible' going on. But, it is however an interesting phenomenon, and something which certainly may turn out to have practical uses in the future.

  • by cyclop (780354) on Saturday September 25, 2004 @04:00PM (#10350256) Homepage Journal

    Well,it's amazing, but it's not the first time i see it.

    I work in molecular biology. Recently we started doing experiments with so-called Matrigel. This is purified extracellular matrix from mice tumours. It's a natural environment to grow endothelial cells and study the development of blood vessels. This is by no means a mysterious substance - thousand of labs buy it and use it every day.

    Well, Matrigel works exactly the same way the substance in the article does. It is fluid around 0, but rapidly freezes at -20 and rapidly becomes solid at room temperature. And it is fully reversible. This also makes the substance a bitch to manipulate -you pick up with the pipette,and it becomes solid inside the pipette before you can transfer it!

    Still, it is amazing to mimic such a behaviour in a simple solution instead than in the tremendous proteins-and-sugars mess that's Matrigel.

  • by bscott (460706) on Saturday September 25, 2004 @04:11PM (#10350322)
    "Body heat activated - when the temperature rises, it fuses your arms to your sides so that you can't release any bad armpit smells"

    OK, I'm just spitballing here.
  • by csoto (220540) on Saturday September 25, 2004 @08:12PM (#10351789)
    This is not novel. This polymer just happens to form weak bonds, as opposed to disulfide, vinyl, ester or other types of strong bonds typically associated with polymers. That's the neat part - they're mostly reversible.

New systems generate new problems.

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