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	Leidenfrost effect
		The Leidenfrost effect is the phenomenon in which a liquid in near contact with a mass hotter than the liquid's Leidenfrost point, which is higher than its boiling point, produces an insulating vapor layer which keeps it from boiling rapidly.
		To demonstrate the Leidenfrost effect at home, just take a normal clean frying pan and heat over a gas stove.
		This effect lasts pretty much until a much higher temperature causes any further drops of water to evaporate too quickly away anyway to this effect.
	www.ebroadcast.com.au /lookup/encyclopedia/le/Leidenfrost_effect.html (355 words)

	Leidenfrost`
		Johann Gottlob Leidenfrost was born in Ortenberg in the County of Stollberg
		Leidenfrost`s observation of the noise when the drop finally disappears, the `particle of earth` and the title of the chapter - On the Fixation of Water...
		The Leidenfrost Phenomenon was not a new discovery.
	volcaniclightning.tripod.com /leidenfr.htm (2890 words)

	Help on Leidenfrost effect
		The same effect happens with a particular plastic surface that as been "polished" (or scratched) with an extremely thin sandpaper OR a surface covered with teflon => there is small "bubbles" of air that gets trapped between the real surface and the water.
		LEIDENFROST EFFECT - Where a liquid will not wet a surface and becomes insulated from the surface by a layer of vapor if the surface is above a critical temperature of the liquid.
		He also said it's the same effect that makes drops of liquid nitrogen dance on the floor or a table top, unless it's a layer of dust that gathers around the surface of the drop instead.
	www.physicsforums.com /showthread.php?t=17508 (656 words)

	PowerPedia:Boundary layer effect - PESWiki
		In the atmosphere the boundary layer is the air layer near the ground affected by diurnal heat, moisture or momentum transfer to or from the surface.
		This effect was exploited in the Tesla turbine, patented by Nikola Tesla in 1913.
		It is referred to as a bladeless turbine because it uses the boundary layer effect and not a fluid impinging upon the blades as in a conventional turbine.
	peswiki.com /index.php/PowerPedia:Boundary_layer_effect (1637 words)

	Composition, apparatus, and method of conditioning scale on a metal surface - Patent 6450183 (Site not responding. Last check: 2007-10-12)
		The strip of steel is at a temperature between the melting point of the alkali metal hydroxide in anhydrous form and a temperature at which the Leidenfrost effect appears.
		As used herein, the term "Leidenfrost effect on the strip" is a mottled or speckled surface appearance of the strip, which reveals patches, or spots of incomplete scale conditioning.
		The conditioning in the present invention occurs as the sprayed solution is heated by proximity of contact with the metal strip and the water is evaporated and the salts are melted by the residual heat in the strip and react with the oxide on the strip surface rapidly, within seconds.
	www.freepatentsonline.com /6450183.html (5289 words)

	Self-Propelled Droplets
		When a liquid drop is placed on a surface that is held at a temperature much higher than the liquid's boiling point (such as a drop of water in a very hot pan) it hovers on its own vapour cushion, without wetting the surface.
		This phenomenon is called the Leidenfrost effect (or film boiling) and occurs beyond a surface temperature called the Leidenfrost point (about 200 - 300 C for water on flat surfaces, depending on surface quality).
		Self-propelled Leidenfrost droplets beautifully demonstrate the general principle of ratchet phenomena: A combination of non-equilibrium (here: the vertical thermal gradient) and spatial asymmetry generally results in transport.
	darkwing.uoregon.edu /~linke/res_droplets.html (353 words)

	POF: Research - Granular Flow - Liedenfrost Effect
		The effect occurs above a critical temperature of 220°C. The drop survives for an astonishingly long time (easily exceeding a minute), because the vapor-cushion prevents direct heat transfer from the hot surface to the droplet.
		The granular version of the Leidenfrost effect can be observed in an experiment with a quasi-2D container filled with glass beads.
		So a density inversion is present in our granular experiment, just as in the original Leidenfrost effect of a water droplet hovering over a hot plate.
	pof.tnw.utwente.nl /3_research/3_g_leidenfrost.html (175 words)

	APS - 2005 APS March Meeting - Event - Leidenfrost Effect of Water Drops on the Surface of Liquid Nitrogen (Site not responding. Last check: 2007-10-12)
		Abstract: H37.00003 : Leidenfrost Effect of Water Drops on the Surface of Liquid Nitrogen
		The properties of small water drops floating on the surface of liquid nitrogen are studied, a type of Leidenfrost effect.
		Heat extracted from the water drop evaporates the liquid nitrogen under it, forming a gaseous dimple that the drop floats on, spinning and moving with constant speed across the nitrogen.
	meetings.aps.org /Meeting/MAR05/Event/25290 (173 words)

	Leidenfrost
		We have studied the Leidenfrost effect of water drops floating above liquid nitrogen.
		The same type of Leidenfrost effect can also be seen for small solid objects dropped onto the nitrogen surface.
		For more details about the experiment and data on the Leidenfrost effect, the REU report on this project can be seen here.
	web.mac.com /garyawilliams/iWeb/Site/Leidenfrost.html (392 words)

	POWERLABS's Cryogenics Department: LN2 Experimentation!
		The Leidenfrost effect occurs when a liquid comes into contact with a surface that is at a temperature much greater than its boiling point, and it causes the liquid to vaporize at such a rate that it forms a layer of insulating vapor between it and the surface.
		A more interesting effect comes when it is poured on the floor: A large puddle shoots across the surface and travels very rapidly until it hits something and becomes spread apart.
		Here is a short (909KB).mpg video showing a beaker being filled with LN2 from the flask and than poured on a 6 X 12cm piece of tissue paper (the kind you use to blow your nose) which, soaked with the cryogen, glides effortlessly over a plastic surface when pushed around.
	www.power-labs.com /ln2fun.htm (1356 words)

	American Scientist Online - Going Against the Flow (Site not responding. Last check: 2007-10-12)
		Linke and his colleagues employed what's called the Leidenfrost effect, which many people have seen in their own kitchens.
		Millimeter-sized water droplets piped onto the superheated sawtooth surface zip off in one direction like airport passengers on a moving walkway, reaching speeds of up to 5 centimeters per second, even if the surface is tilted so that the droplets have to climb uphill.
		This time, the external force makes the fluxon in the shallower well push into the deeper well, repelling the fluxon that's already there and popping it out of the step in what is supposed to be the "hard" direction of the ratchet.
	www.americanscientist.org /template/AssetDetail/assetid/51987 (1055 words)

	Reverse Leyden Frost Effect (Site not responding. Last check: 2007-10-12)
		The reverse leyden frost effect causes the ball to be covered by frost while in the flame.
		Place a brass ball into liquid air in a clear dewar and observe the initial leidenfrost effect.
		When the ball is cold, place it in a flame and observe the reverse leidenfrost effect as frost forms on the ball while it is in the flame.
	demoroom.physics.ncsu.edu /orders/demos/518.html (124 words)

	Leidenfrost Effect, Schema-Root news (Site not responding. Last check: 2007-10-12)
		A: The surprising phenomenon you describe is called the Leidenfrost effect, after the German physicist who described it.
		The phenomenon known as Leidenfrost effect sees water droplets in motion where they glide in random directions on a bed of vapour formed between the droplets...
		In a phenomenon known as the 'Leidenfrost effect,' water droplets can perform a dance in which they glide in random directions on a cushion of vapor that forms...
	schema-root.org /science/physics/effects/leidenfrost (239 words)

	Session FC - Drops.
		Pulsed shadowgraphy and holography were used to find the location of the onset of a roughened liquid surface, liquid surface velocities, the location of the onset of turbulent primary breakup, and drop size and velocity distributions after turbulant primary drop breakup along the liquid surface.
		The effects of the mass loading ratio, the particle time constant, and thermodynamic parameters such as the specific heat ratio and the boiling temperature on the turbulence and the droplets are considered.
		Pressure and temperature effects from the microexplosions increase the droplet temperatures and evaporation rates resulting in increased dispersion as well as a decrease in droplet lifetimes.
	flux.aps.org /meetings/BAPSDFD96/abs/S750.html (1882 words)

	The Straight Dope: Can you walk on hot coals in bare feet and not get burned?
		As a classroom demo of the Leidenfrost effect, Jearl not only walked on hot coals (he gave it up after getting badly burned once--he was so cool his feet didn't get sufficiently damp), he also dips his bare hand in water and then plunges it momentarily into a vat of molten lead, 700 degrees Celsius.
		Bernie discounts the Leidenfrost effect, noting that a firewalker with a pair of rope- sole sandals gamboled through the coals without damage to the sandals.
		However, any time you've got a phenomenon that lets you work in a Jearl-Walker-tempts-death story, as was the case with the Leidenfrost effect, in my book you want to cut it a little slack.
	www.straightdope.com /classics/a3_036.html (942 words)

	BBC NEWS \| Science/Nature \| Scientists make water run uphill
		The US scientists did the experiment to demonstrate how the random motion of water molecules in hot steam could be channelled into a directed force.
		But the team, writing in Physical Review Letters, believes the effect may be useful in driving coolants through overheating computer microchips.
		The effect was described in the 18th Century by a German scientist Johann Gottlob Leidenfrost.
	news.bbc.co.uk /2/hi/science/nature/4955398.stm (514 words)

	Cu Measurements (Site not responding. Last check: 2007-10-12)
		The effects of the lower resistance can be easily seen by observing the effect of induction.
		The same process of induction is responsible for an effect often refered to as eddy current braking.
		Although not related to measurements of DC resistivity, the students witnessing the demo enjoyed watching the Leidenfrost Effect.
	www.physics.ubc.ca /~outreach/phys420/p420_96/bruce/copper.html (553 words)

	FireWalker - Fire Walking
		This is termed the Leidenfrost Effect, and is named after the man who first documented it.
		The Leidenfrost Effect can be easily observed by placing a few drops of water on a hot metal plate.
		There may be a Leidenfrost effect when fire walking - but it is not a significant effect and most certainly can not explain the phenomenon.
	www.firewalker.co.uk /fire_walking/fire_walking.htm (1494 words)

	The Leidenfrost Effect-VHS (Site not responding. Last check: 2007-10-12)
		The basic demonstration of the Leidenfrost effect is presented: a water drop lasts about one second on a skillet that is at a temperature of 150C but up to 1.5 minutes when the skillet is hotter than 200C.
		The radiation and conduction of heat through a vapor layer is discussed.
		Finally, the Leidenfrost effect is put to work as Walker strolls across a bed of hot coals.
	gpn.unl.edu /static_catalog/73_005.html (81 words)

	What is the Truth? (page 2)
		The effect is not mystical, it a has scientific basis:
		The effect can be seen in action by shaking droplets of water on to a hot skillet and watching the droplets bead up and dance around instead of instantly evaporating.
		Other scientists believe that the Leidenfrost effect is unimportant in fire walking.
	tkdtutor.com /03School/Fraud/WhatsTheTruth/WhatsTheTruth02.htm (991 words)

	Firewalking: Keys to Psychology, Success, Motivation & Goals
		The first thing to understand is that firewalking, like lying on a bed of nails or dipping fingers into molten lead, is definitely not an exercise in "mind over matter." It can be explained by basic principles of physics, and is sometimes even used as a classroom demonstration by physics professors.
		In addition, although the coals are very hot, they are inefficient when it comes to transferring that heat to your feet (as physicists would put it, coals are low in "heat capacity" and "thermal conductivity").
		To have truly lasting effects, firewalking must be combined with a vision of what you want to accomplish, and a strategy for making it a reality.
	www.realscienceofsuccess.com /Science_of_Firewalking.htm (1542 words)

	CBC Nova Scotia \| Programs \| Information Morning \| Columnists \| Science Corner Archive 2007
		Answer: The drop dances because it is hovering on steam; the Leidenfrost effect.
		When the drop hits the stove, some of the water evaporates and the rest of the drop sits on that steam.
		Answer: The spoon acts like it does because of the Bernoulli effect; the water rushing against the rounded side reduces the pressure on that side while the pressure on the other side stays the same, so the effect is that the spoon is pushed into the water
	www.cbc.ca /informationmorningns/science-archives/2007_science.html (2035 words)

	Water:An Eternal Component Of The Earth---Experiment 4 (Water drops riding on steam)
		This surprising behavior of water drops on a hot surface is called the Leidenfrost effect.
		As the drop of water comes in contact with the metal surface, the outer layer of the drop begins to vaporize (change from a liquid to a gas).
		In the Leidenfrost effect, only that part of the drop that touches the hot surface changes to steam.
	library.thinkquest.org /C0126220/experiment/experiment4_e.htm (548 words)

	kanamyxin's Xanga Site
		COM, also centre of mass, of a system of particles refers to a point as though (1) all the masses of the particles are concentrated at that point (2) all other external forces are applied.
		It is an effect that surface only upon heating a liquid beyond its boiling point.
		The Leidenfrost effect is to describe the effect of the longer lifespan of water droplets on hot surfaces that are more than 200'C. It is due to film boiling that lead to the slow heat transfer and hence longer lifespan of the water droplets.
	www.xanga.com /home.aspx?user=kanamyxin (670 words)

	Re: [ERPS] TPS options
		Basically, a thin film of water will protect an underlying surface from even more heat than you would normally effect, because the thin boiling layer at the surface of the liquid is a good insulator.
		The Leidenfrost effect is actually a nuisance because it limits the heat transfer; you're trying to suck heat from the base and transfer it into water and the layer gets in the way.
		If the bottom of the vehicle is wet, then the Leidenfrost effect is on your side, because it reduces heat transfer to the skin of the vehicle.
	www.mail-archive.com /erps-list@lists.erps.org/msg02078.html (257 words)

	[No title]
		Science notes When the spoon is very hot, a layer of steam forms between the drop and the spoon.
		This has a number of effects: It greatly reduces friction between the drop and the spoon.
		This effect is known as the Leidenfrost effect or vapour blanketing.
	www.gla.ac.uk /ibls/sts/experiments/teachers/feb06.doc (402 words)

	Halfbakery: Leidenfrost Pods
		Btw, I am lucky enough to see this effect all the time, at the electric arc furnace, and steel casting machine.
		All entirely non-feasible of course, as the friction and heat forces would melt the croissant hood ornaments and theres no way I'm driving anything without a croissant hood ornament.
		[Ling] //Btw, I am lucky enough to see this effect all the time, at the electric arc furnace// I'm glad you have that connection - us males see it very, very often when we utilise urinals that have cold stainless steel troughs - so 'boys' usually are quite familiar with the Leidenfrost effect.
	www.halfbakery.com /idea/Leidenfrost_20Pods (503 words)

	Keith Devens - Weblog: Leidenfrost effect - October 13, 2002
		Home » Archive » 2002 » October » 13 » Leidenfrost effect
		This guy has stuck his hand into boiling lead, walked on hot coals, and put liquid nitrogen into his mouth.
		He explains something I've always wondered about - where if you heat up a pan with nothing in it for long enough, then put water drops on it, they will roll around like mercury.
	keithdevens.com /weblog/archive/2002/Oct/13/LeidenfrostEffect (105 words)

	Re: Hypnosis found to alter the brain: Subjects se
		I recall that the walk-across-fire feat is enabled by the Leidenfrost effect.
		Rather, I want to let you know what effect your argument has, and how, if you want, to really encourage research in the fields that you are interested in, do alot of reading, and not from "new age" authors, and really get to understand the ideas behind how things work.
		If you want examples of how environmentally induced forms of hypnosis effect people, simply read any of the modern sociological critiques that are available.
	cognews.com /1075222204/1075281380/index_html (857 words)

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