Catch up on stories from the past week (and beyond) at the Slashdot story archive

 


Forgot your password?
Close
typodupeerror
×
Science

Melting Away Ice Hazards 131

Posted by michael from the electrifying-discoveries dept.
RadioheadKid writes "Dartmouth College Professor Victor F. Petrenko is getting a grip on ice. He and his colleagues have found ways to take advantage of the "protonic" semiconductor properties of frozen water. They see many applications of this discovery from melting ice on power lines to electronic speed control for skis and snowboards. I guess those Petrenkos just love the ice."
This discussion has been archived. No new comments can be posted.

Melting Away Ice Hazards More

Melting Away Ice Hazards

Comments Filter:
  • the idea of someone being at an Ice Conference is troubling.
  • Using this on skis and snow mobiles would be interesting. If this discovery is applicable to real life beyond melting lines, it could be very powerful. I doubt it will be life changing though. Most discoveries add small conveniences to life.
    • Living in Vermont I'd love to be able to hit a switch and have my tires "get a grip" on the ice. I bought Petrenko's text book and I'm slowly making my way through it. Many, many years ago I read an article on how ice is a semiconductor. The authors of that article made transistors (bipolar IIRC) using ice doped with something I can't remember. Petrenko makes a FET using ice but he uses a silicon wafer for making the gate. If anyone reading this knows how to make a BJT using ice please let me know! Its of absolutely no practical use but it sure would be interesting. Email: kiatoa@kiatoa-remove-me-.com
  • Now those guys who can go 150mph downhill will be able to go 200mph...

    If that doesn't change your life for the better, I don't know what else would...

    • Re:Great... (Score:2, Interesting)

      by mattcasters ( 67972 )
      Actually, the record is 248.105km/h or 154mph. A man named Harry Egger did it.

      WorldRecord 1999 [speedski.com]

      I've seen them ski in Les Arcs (France) in 1999 and although the view was very impressive, since then I'm convinced that these people are completely nuts or incredibly brave. :-)

      Furthermore, I think that reducing ski-resistance is not going to help these people. I think it's wind resistance that's holding them back.

      Cheers, Matt

      • I'm not making any sense? My head's filled with things like

        POKE 53280,0

        POKE 53281,0


        Argh! That's black border, black screen! God Almighty, my brain is full of the same thing too, and I didn't even know it!

      • Furthermore, I think that reducing ski-resistance is not going to help these people. I think it's wind resistance that's holding them back.

        Well, just wait. It won't be long before some other mad scientist invents aerodynamic human to take care of that problem!
  • Couldn't this also be applied to vehicle tires? I know I just had a hell of a time driving home tonight, with all the frozen rain on the roads. I've got expensive snow tires on my vehicle, but on slick ice like this, I might as well have a set of skates. I don't know if its a workable (or affordable) solution, but I know I would pay good money to have some additional traction for these icy Canadian west coast winters.

    • Re:Car traction? (Score:2, Insightful)

      by absurdhero ( 614828 )
      I think a lot of electricity would be required to melt that volume of ice almost instantaniously. power lines are stationary. they can afford to run it for 10 seconds or even minutes to melt it. Spinning tires are a different story, Im afraid.
      • I too was afraid of spinning tires.. Then one day, my dad set me in front of a pitching machine and the ball smacked me in the head. To this day my fear is displaced to my father and that cute dimply baseball.

    • try the second link (Score:3, Informative)

      by The Tyro ( 247333 )
      They are claiming a theoretical traction increase of 90%(!) potentially using some kind of conductive rubber in car tires.

      What's most interesting about the opposite application (deicing) seems to be that they are using the ice to melt itself.

      The deicing will clearly be more efficient, since resistive heaters are so very inefficient... but they should still have to expend at least the amount of energy that would be needed to convert the ice to water... 80 calories per gram, if I recall my Heat of Fusion values correctly (physics was like 15 years ago, so I may have that totally wrong)

      Still, to avoid all those losses from inefficient resistive heaters? Potentially very lucrative tech here.

      They even have prototypes already... I'm impressed.

      • Re:try the second link (Score:2, Informative)

        by pyrote ( 151588 )
        ya they mention a power module every 100 kilometers using only 50 watts. not bad compared to normal resistive technologies
      • Actually, resistive heaters are 100% efficient if you ignore the losses in transmission lines (i.e. they convert 100% of the electricity you put into them into usable heat). Now, getting that heat to the ice to melt it is another matter, but it has nothing to do with resistive heaters.
        • Oh now, I'm not too sure about all that... Turn your [electric] stove on. Turn your hair drier on and LOOK at the heating element. Mmhmm. LIGHT energy.

          Nothing is 100% effifient except people... They annoy me 100% of the time.
      • they should still have to expend at least the amount of energy that would be needed to convert the ice to water... 80 calories per gram

        But they don't need to convert ALL of the ice to water. This process works by just heating the microscopic surface layer of the ice. Once the layer bonding the ice to the wing has melted the the rest of the ice can slide off nearly friction-free.

        -
      • metamoderating, and then i see this.

        pain...behind...left...eye...

        inner pedant crying out...

        three hundred thirty three joules per gram

    • Re:Car traction? (Score:1)

      by Anonymous Coward
      Couldn't this also be applied to vehicle tires?

      Perhaps reading the articles would help? They specifically mention an increase of 90% in tire traction.

  • Fascinating stuff (Score:4, Interesting)

    by The Tyro ( 247333 ) on Saturday December 28, 2002 @06:15AM (#4971561)
    Protons carrying the charge, hmmm? I suppose any charged particle could theoretically carry a current, but I must admit I never thought of "proton flow" as a way to do it...

    Water really is an interesting material.

    Universal solvent (polar solvent, for you organic chemistry nitpickers)

    Has its greatest density BEFORE it reaches its solid state of matter (ice). If you ever wondered why ponds and rivers don't freeze from the bottom up, that's the reason. Someone correct me, but I think the temperature of greatest density is 39F.

    That's really quite a discovery... can't wait to see if they can make something useful out of it.

    • 4 deg C is greatest density (Score:4, Informative)

      by spineboy ( 22918 ) on Saturday December 28, 2002 @11:17AM (#4972064) Journal
      That's for relatively pure water, and that works out to be about 39 deg F. OF course adding salts and other things to raise the molarity (ionic concentration) of the water will depress the freezing point - I've forgotten what it'll do tho the density curve something about packing inefficiencies
    • Actually, proton flow occurs regularly in nearly every cell of your body- mitochondria use the energy of electrons from glycolysis and the Krebs cycle in the electron transport chain to pump protons across the inner membrane of the mitochondrion using transport proteins. This creates an electrochemical proton gradient- since the concentration of protons outside is greater than inside, osmotic pressure is created, and since protons are charged particles, a voltage across the membrane also exists. These protons, which have high potential energy, want to "fall" back to a lower potential energy state inside the membrane, but they need a transport protein to let them get back across. ATP synthase fills this role nicely, and as its name suggests, also serves another purpose. ATP synthase is like an electric motor, using the energy of the flowing protons to power conversion of ADP to ATP, which can then be used to power cell activities.

      Come to think of it (no pun intended- you'll see what I mean), in neurons, a voltage gradient is set up not using electrons or protons, but rather large (relatively) ions, specifically Na+ and K+. The activity of these pumps, along with the net charge associated with proteins in the neurons, produces a neuron resting potential of about -70 millivolts relative to the outside of the cell. Nerve impulses travel up and down the long thin neurons by a carefully choreographed operation of ion channels and pumps in the cell- the ion channels are voltage gated, so a nearby chnnge in potential results in ion channel opening, allowing a flood of positive sodium ions back into the neuron, causing the cell to become depolarized. Since a nearby depolarization triggers further depolarization along the length of the neuron, the changing electrical potential in the neuron can be seen as a wave racing down its length. At gaps between neurons (synapses) the electrical signal causes the release of a chemical neurotransmitter like acetylcholine or GABA, which diffuses to the terminus of another neuron, triggering the electrical signal again. In this way, the flow of ions leads to nerve impulses, and thus, even thoughts.
  • I can already see the headlines
  • New Scientist linked this story [newscientist.com] from the ice piece. I know this is sorta OT, but wow, I'm always stunned when I read a hail story like this.

    Ice not nice.
  • He and his colleagues have found ways to take advantage of the "protonic" semiconductor properties of frozen water...
    That's bad right?

  • Europa Exploration? (Score:4, Insightful)

    by MystikPhish ( 218732 ) <ryan@fishersDEGASr.us minus painter> on Saturday December 28, 2002 @06:40AM (#4971599)
    So could this effect be applied to the skin of a Europoa ice rover that would melt its way through 2km of ice?

    I always hear that using heat to melt it would be impractical, but with a drill and this electric field effect maybe something more energy efficient could be done?
  • "they see many applications of this discovery from melting ice on power lines to electronic speed control for skis and snowboards". Yes this discovery is a step further in the development of the mankind... Speed control for skis and snowboards..., this is an example how science can revolutionize the world (and solve some of its toughest problems). Fantastic!
  • "After you, I'll be waiting for you down there." ;)
  • The article mentions the possibility of making car tires that get 90% better grip in icy conditions, yet this article cares more about skiers.

    For some reason, I'm thinking someone's vision on the uses for technology is a little out of focus here.
    • The article mentions the possibility of making car tires that get 90% better grip in icy conditions, yet this article cares more about skiers.

      For some reason, I'm thinking someone's vision on the uses for technology is a little out of focus here.
      ...Or maybe they don't live in shockingly cold places like many of the rest of us (Minneapolis, MN here -- hi everyone) where they need to DRIVE in conditions like that constantly for 5-7 months of the year. It is one thing to live in Southern California and take a drive to the mountains to ski every once in a while -- it is something else completely to have to drive 20 miles to work on a frozen freeway...
    • Well I suppose if you're a skier this is great news. And I'm a skier, so I'm really happy about this news. There's nothing wrong with this guy's "focus". I'm sure you'd think differently about Micro$oft releasing some new [useful] software that the Slashdot readership thinks should be FREE and open source. Obviously, Bill Gates and his goons are a little out of focus.
    • seeing as this comes from Dartmouth in northern NH I'm not surprised, skiing is a way of life up there and if people can't deal with the ice they have probably moved away.
  • Slashdot had an article [slashdot.org] on this back in February.

  • How skis work (Score:2, Interesting)

    by squidgyhead ( 613865 )
    The article talks about how their discovery can be applied to skiing, and, analogously, driving and a bunch of other stuff, by melting ice and making it more or less slippery, depending on the interval between meltings. Small interval => more water, less freezing, large interval => more freezing, less slippery water. You get the idea.


    I imagine that most of you know the ideal gas law, ie that pressure and temperature are (almost) linearly related. So, if you increase the pressure, you should be able to melt snow or ice, right? If it gets colder, you just squeeze harder. This means that warm snow should be slipperier, since you can melt more snow, which will lubricate better, right?


    Unfortunately, below 30 degrees Celsius or so, there is no way to get water, no matter what pressure you apply. Look at the following ice/water/vapour [sbu.ac.uk]
    diagram. You will notice that vapour and liquids don't take up much of it, it's ice almost everywhere. And all ice below 240K (=-33C) or so.


    So how could we possibly ski at below -33C? The answer is that we just slide on the snow. Occam's razor, ya?

    • Being a responsible Slashdot regular and having not read the article, I don't know where the idea of melting snow to aid in skiing came from. Either you or the article is getting this confused with *skating*. The blade of an ice skate combined with the pressure of your body melts a thin layer of water, providing lubrication. Skis generally have a layer of wax applied to them to provide enough lubrication on the snow - at least cross-country skis, which is all I've ever tried.

      How does one skate at colder than -33C? Simple. That pressure heats up the ice underneath you first, and then it can undergo phase transition.

      Living in a really cold part of Canada is always good for useless cold-weather trivia, and yes, I've actually skated at colder than -40 (F or C, same difference at that point).

  • Just you wait! Global warming should take care of this little ice problem we have down here;-) Can't speak for a couple of miles in the atmosphere...

  • piezoelectric roads? (Score:2, Interesting)

    by sporkboy ( 22212 )
    The low power requirements of a system like this remind me of an idea that I had a while back. High-ice surfaces such as bridges (freeze first) could be equipped with a system like this to melt the ice, and the power for the system could be generated by the pressure generated by the weight of passing vehicles. Some sort of storage mechanism would be needed, at least small scale, to keep the ice off when traffic isn't passing.

    Of course IANAEE (I am not an electrical engineer) so I could be speaking from the wrong end here. Not sure on costs of such a system either but it seems like it could have benefit, especially considering how expensive bridges are to begin with.
    • piezoelectric roads?

      too hard to generate consistent currents with piezo. Piezo effect creates sharp, sparky jolts. Cheaper and easier to just plug the whole thing into the power grid and be done with it.

  • Why don't I see this as particularly revolutionary? Well, forget the problems of transferring power to rotating car wheels for a moment, consider that significant design changes would almost certainly be needed to make use of such a technology on overhead power lines, bridges, airplane wings etc.

    And the life cycle of such things is enormous. There are standards (codes in USenglish) to consider, which will need to be altered. Given the fear of litigation over design failure, the difficulty of proving the cost benefits, and the innate conservatism of people who make things that can be involved in major catastrophes, the development cycle could well be fifty years or more before there was any widespread application.

    And perhaps that's why snowboards get mentioned. Like piezo tennis rackets, there will be early adopters who aren't actually very good at winter sports but have lots of cash and who will attribute the improvement that comes with practice to the miracle technology...might just sell.

    • Yeah! (Score:2)

      by mtec ( 572168 )

      If Man were meant to fly, he'd have wings!

      And if he does, just think of the lawsuits!
    • Depending how heavy the equipment is, the design change for aircraft wings (especially light aircraft) probably wouldn't be significant. Already, many aircraft types can have pneumatic de-ice boots retrofitted and hot props retrofitted or TKS 'weeping wing' glycol deicers fitted. Assuming this system weighs no more than the usual deicing stuff and can fit the leading edges of wings/tailplanes/propellors it could be a LOT better than boots (high maintenance), weeping wing (lots of fluid to carry around) or hot props (lots of amps off the alternator).

      The real problem would probably be regulatory. The FAA is slow to approve things. Company lawyers are frightened of aircraft (because for some insane reason, plaintiffs have this misplaced belief that planes should be absolutely safe with no risk of crashing, and if there's ever an accident they sue anyone who has even touched the airframe). Also, the limited market tends to mean that new innovations in aviation tend to get limited to things that can be adapted from something else. The only thing that's really advanced in general aviation (i.e. non-airlines/military) has been avionics because of this.

  • solar power (Score:3, Interesting)

    by roman_mir ( 125474 ) on Saturday December 28, 2002 @11:26AM (#4972086) Homepage Journal
    "Many properties are completely different, but there are similarities between ice and the usual semiconductors," he says. For instance, he discovered that ice crystals can exhibit protonic photoconductivity. "It would be possible to create an ice solar cell," albeit one with substantially lower efficiency than silicon. Field effect transistors made of ice have also been developed that "work the same way as silicon."

    Ok, who right away thought of turning north and south poles into electricity generating power plants?

  • what a cool guy... (Score:4, Funny)

    by mtec ( 572168 ) on Saturday December 28, 2002 @12:10PM (#4972211)
    There once was a man named Petrenko
    who found flow where you'd not think to think so
    In white Russian ice
    he could make juice flow nice
    now he dreams of cool cash and green dough
  • Observe it's effect on this ice swan:

    {fizzlemelt}

    Of course, that would've melted at room temperature, but I just wanted to get rid of it.
  • There must be something definitely wrong. From the article:
    It runs off small power units placed along the lines every 100 kilometres or so. The signal does not reduce electricity transmission through the cables, and because it uses around 50 watts per 100 kilometres of line it should cost a fraction of what it normally takes to keep the lines clear

    So 50 watts per 100 kilometres shall be enough to melt quite a lot of ice? there is a lot of energy needed to transform ice of 0 C to water of 0 C, about 80 kcal = 320 kilojoule, so 320 kilowatts for one second or 88 watts for one hour. 50 watts will melt less than one kilogram of ice per hour, and that should be enough on a length of 100km cable?
    I doubt it.


    • Perhaps they are only thinking of melting the thin layer of ice that holds the rest onto the wire?

    • Agreed. Sounds like a load of pseudo-science fantasy from some unpeer-reviewed N00bie Scientists. AFAICR from physics, only electrons can conduct charge. Also, that's only about .0005W/m. Another problem, the lines are usually thickly insulated with rubber or something.

      Wouldn't it be cheaper to melt ice using two larger, parallel loads switched alternately between two sets of lines (PWM)? Also, every line should have a temp sensor to allow for temperature-compenstated capacity throttling. And for urban/suburban runs, for shit's sake put those ugly cables underground!

      Also related: we need more spending on fusion power research so we can break our oil addiction. a fusion plant that produces a net gain in energy is likely to be huge, costing several G$. maybe solar+wind -> hydrogen is the way to go? replace natural gas w/ LH2? do your own electricity generation near home?

      My .002 decadollars.

  • Wireless skis (Score:3, Interesting)

    by isdnip ( 49656 ) on Saturday December 28, 2002 @04:12PM (#4972992)
    I like his adjustable skis. But how do you set the speed? It's not practical to bend over and tweak a knob on top while going down a hill; at least, it would not be good style.

    But if the control circuit used, say, Bluetooth, and the control buttons were in, say, the pole handles, then the skier would have good control while staying in motion. This could be quite nice.

    (If somebody tries to patent the idea with a later date than today, remember, you heard it first on Slashdot, making it potentially Prior Art.)
  • From Men's Figure Skating History [yahoo.com]

    ALBERTVILLE 1992:

    Gold - Viktor Petrenko, Unified Team
    Silver - Paul Wylie, United States
    Bronze - Petr Barna, Czechoslovakia

    He's been studying ice all his life

  • Since only one side of the interface needs high thermal conductivity, this system can also be adapted to car tires, as well as shoe soles--using electrically-conductive rubber--to increase traction on ice by up to 90%.

    Where do you find rubber like that?

    -v
  • Does anyone remember that agony of defeat [ew.com] guy from the old ABC Sport intro? Now imagine a lot more teenagers doing impressions of that guy becuase the tried to make their skis "faster".

    Then again, maybe it'll remove some of the stupid people in the world.

Slashdot Top Deals

1 + 1 = 3, for large values of 1.

Close