What-If 0050: "Extreme Boating"

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What-If 0050: "Extreme Boating"

Postby Quicksilver » Tue Jun 18, 2013 6:53 am UTC

http://what-if.xkcd.com/50/

What would it be like to navigate a rowboat through a lake of mercury? What about bromine? Liquid gallium? Liquid tungsten? Liquid nitrogen? Liquid helium?
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Not much luck this week, it seems :( Would Liquid Tungsten be close to a universal solvent?

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What-If 0050: "Extreme Boating"

Postby Vroomfundel » Tue Jun 18, 2013 6:59 am UTC

What would it be like to navigate a rowboat through a lake of mercury? What about bromine? Liquid gallium? Liquid tungsten? Liquid nitrogen? Liquid helium?

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And what about gas?
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Re: What-If 0050: "Extreme Boating"

Postby Mikeski » Tue Jun 18, 2013 7:17 am UTC

Quicksilver wrote:Would Liquid Tungsten be close to a universal solvent?

"Let's find out, Mister Bond."

(adds one human to his vat of liquid tungsten*)

(observes rapid oxidation of said human)

Burning and dissolving are not the same thing. So, no.

* - if anyone would have a vat made of tantalum hafnium carbide, it'd be a Bond villain, right?

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Re: What-If 0050: "Extreme Boating"

Postby rivulatus » Tue Jun 18, 2013 7:20 am UTC

Mmmm, I need to get myself some Liquid gallium.

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Re: What-If 0050: "Extreme Boating"

Postby Tittah » Tue Jun 18, 2013 7:36 am UTC

Why should a splashfight in a lake of mercury be avoided? I was taught to believe that liquid mercury is not harmful, even when swallowed.

It would make an excellent work-out me thinks...

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Re: What-If 0050: "Extreme Boating"

Postby helo darqness » Tue Jun 18, 2013 7:43 am UTC

Doesn't he mean liquid Tungsten is so hot that it would freeze Lava, not the other way around?

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Re: What-If 0050: "Extreme Boating"

Postby phlip » Tue Jun 18, 2013 7:44 am UTC

Tittah wrote:Why should a splashfight in a lake of mercury be avoided? I was taught to believe that liquid mercury is not harmful, even when swallowed.

Less harmful, perhaps. I still wouldn't want to mess with it.

Besides, a splashfight is going to increase the amount of mercury droplets in the air, and generally a greater surface area, which is going to result in more of it being evaporated...

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Re: What-If 0050: "Extreme Boating"

Postby Carlington » Tue Jun 18, 2013 7:51 am UTC

No, if a hot thing and a cold thing come into contact, the hot thing gets colder and the cold thing melts. Hot water in cold air, for example - the water is so hot that the air freezes it.

Also, there's a What If? subforum now.
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Re: What-If 0050: "Extreme Boating"

Postby tups » Tue Jun 18, 2013 7:56 am UTC

There are other oddities contained in this what-if page.

I would like to see the maths that proves me that "it would be impossible to move fast" on a mercury lake. Who calculated this ? The lack of paddle depth may well be compensated by the lack of depth of the boat itself - what are the dynamics governing the rowing process ? Is there an equation for it ? What about the statement that it is easier to row a boat on a gallium lake ? In both Ga and Hg splash fights would be more or less OK, but for the mercury, a self-contained breathing apparatus would be recommended, it's the vapours that are dangerous, because they oxidize to organomercury compounds, which are poisonous as hell. The liquid is harmless (apart from producing vapours). The lake will remain a very serious environmental hazard over a large area after you're done boating. Covering it with another liquid, preventing evaporation of the mercury would be recommended.

The density of bromine is not "about the same as water". It is in fact very heavy, about 3100 kg/m³. You'd need a stainless steel or glass paddle, a boat made out of similarly inert materials, and a full body suit with a breathing apparatus if you'd want to survive your boat trip.

Three out of five warnings about liquid nitrogen are really about liquid oxygen - that is cheating, as it would only apply when the lake has just about disappeared, and the condensed oxygen would have concentrated. Liquid nitrogen is relatively harmless stuff, apart from not supporting respiration and being very cold. Obviously you'd need either a self-contained breathing apparatus or a stiff wind over a small lake, and warm clothing. This would make it a rather magical trip i.m.o., given those conditions, I'd like to try it.

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Re: What-If 0050: "Extreme Boating"

Postby Klear » Tue Jun 18, 2013 8:20 am UTC

tups wrote:I would like to see the maths that proves me that "it would be impossible to move fast" on a mercury lake. Who calculated this ? The lack of paddle depth may well be compensated by the lack of depth of the boat itself - what are the dynamics governing the rowing process ? Is there an equation for it ? What about the statement that it is easier to row a boat on a gallium lake ? In both Ga and Hg splash fights would be more or less OK, but for the mercury, a self-contained breathing apparatus would be recommended, it's the vapours that are dangerous, because they oxidize to organomercury compounds, which are poisonous as hell. The liquid is harmless (apart from producing vapours). The lake will remain a very serious environmental hazard over a large area after you're done boating.


I imagined it like rowing a boat on a frozen lake. That's gonna be hard work.

tups wrote:Covering it with another liquid, preventing evaporation of the mercury would be recommended.


Liquid helium, preferably.

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Re: What-If 0050: "Extreme Boating"

Postby taemyr » Tue Jun 18, 2013 8:38 am UTC

tups wrote:The density of bromine is not "about the same as water". It is in fact very heavy, about 3100 kg/m³.


Wheras water is 1000kg/m³. So about the same. You would have a noticably more buoyancy, but you would be floating in rather than standing on the liquid.

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Re: What-If 0050: "Extreme Boating"

Postby siebje » Tue Jun 18, 2013 9:07 am UTC

I call dibs on the band name "The Third Sound"! :)

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Re: What-If 0050: "Extreme Boating"

Postby bigblen » Tue Jun 18, 2013 9:09 am UTC

Wondering if this is inspired by the lake of mercury that appears in Iain M Banks (may he rest in peace) book Surface Detail?

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Re: What-If 0050: "Extreme Boating"

Postby Showsni » Tue Jun 18, 2013 9:15 am UTC

Mostly what I got was "don't use aluminium boats."

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Re: What-If 0050: "Extreme Boating"

Postby speising » Tue Jun 18, 2013 9:20 am UTC

two degrees kelvin?

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Re: What-If 0050: "Extreme Boating"

Postby Angelastic » Tue Jun 18, 2013 9:36 am UTC

tups wrote:Three out of five warnings about liquid nitrogen are really about liquid oxygen - that is cheating, as it would only apply when the lake has just about disappeared, and the condensed oxygen would have concentrated.

On a related note, "and you and the boat would be smothered in a thick fog as the water condensed out of the air. (This is the same effect that causes steam when you pour out liquid nitrogen.)" is a bit misleading, because the fog you see when you pour out liquid nitrogen is made of liquid oxygen. The water does condense out of the air (as a solid) but that's not the thick fog you see.
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Re: What-If 0050: "Extreme Boating"

Postby Vroomfundel » Tue Jun 18, 2013 10:17 am UTC

Haha, I've been wondering for a while why no one posts it for so long :-) lat time, AFAIR, no one pointed this out
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Re: What-If 0050: "Extreme Boating"

Postby Vroomfundel » Tue Jun 18, 2013 10:23 am UTC

As I said in the wrong subforum, why not row a boat on gas?

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Re: What-If 0050: "Extreme Boating"

Postby squonk » Tue Jun 18, 2013 11:04 am UTC

helo darqness wrote:Doesn't he mean liquid Tungsten is so hot that it would freeze Lava, not the other way around?

Is a fire so hot that it would freeze your hand?

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Re: What-If 0050: "Extreme Boating"

Postby Maxikov » Tue Jun 18, 2013 11:35 am UTC

A Dartmouth engineering page on liquid nitrogen safety includes the following phrases:

"violent reactions with organic materials"


How is that possible? I know that monoatomic nitrogen is a strong oxidizer, but in its normal diatomic form the bond is so strong that it requires the temperature of an electric spark or a sophisticated catalyst to make it react with anything. Liquid nitrogen is very cold, so the activation energy for reactions is even higher. How on earth can it cause violent reactions with organic materials?

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Re: What-If 0050: "Extreme Boating"

Postby Copper Bezel » Tue Jun 18, 2013 11:50 am UTC

I can't find anything to back up the claim, and the MSDS is very explicit about the only dangers of liquid N coming from its temperature and the fact that the gas is potentially asphyxiant.
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Re: What-If 0050: "Extreme Boating"

Postby Klear » Tue Jun 18, 2013 11:51 am UTC

squonk wrote:
helo darqness wrote:Doesn't he mean liquid Tungsten is so hot that it would freeze Lava, not the other way around?

Is a fire so hot that it would freeze your hand?


Of course, it's not hot enough to get frozen by my hand either... =P

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Re: What-If 0050: "Extreme Boating"

Postby Diadem » Tue Jun 18, 2013 11:55 am UTC

Maxikov wrote:
A Dartmouth engineering page on liquid nitrogen safety includes the following phrases:

"violent reactions with organic materials"


How is that possible? I know that monoatomic nitrogen is a strong oxidizer, but in its normal diatomic form the bond is so strong that it requires the temperature of an electric spark or a sophisticated catalyst to make it react with anything. Liquid nitrogen is very cold, so the activation energy for reactions is even higher. How on earth can it cause violent reactions with organic materials?

Stick your hand in a jar of liquid nitrogen, hold it there for half a minute, take out your hand. Admire what is left of your hand.

Is that not a violent reaction?

Yes, it is due to temperature alone, but that doesn't make it any less dangerous. Remember, the word 'reaction' has more meanings that just the chemical one.
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Re: What-If 0050: "Extreme Boating"

Postby Barstro » Tue Jun 18, 2013 12:27 pm UTC

I just saw that there is an entirely different Thread for What-Ifs. Is there a way for a Moderator to join them, or would other people just keep making What-Ifs in the Individual thread?

More on point; I'm surprised Randall didn't go into how boats would need different configurations to have correct balance in mercury, etc.

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Re: What-If 0050: "Extreme Boating"

Postby cellocgw » Tue Jun 18, 2013 12:39 pm UTC

Klear wrote:
tups wrote:I would like to see the maths that proves me that "it would be impossible to move fast" on a mercury lake. Who calculated this ? The lack of paddle depth may well be compensated by the lack of depth of the boat itself - what are the dynamics governing the rowing process ? Is there an equation for it ? What about the statement that it is easier to row a boat on a gallium lake ? In both Ga and Hg splash fights would be more or less OK, but for the mercury, a self-contained breathing apparatus would be recommended, it's the vapours that are dangerous, because they oxidize to organomercury compounds, which are poisonous as hell. The liquid is harmless (apart from producing vapours). The lake will remain a very serious environmental hazard over a large area after you're done boating.


I imagined it like rowing a boat on a frozen lake. That's gonna be hard work.

tups wrote:Covering it with another liquid, preventing evaporation of the mercury would be recommended.


Liquid helium, preferably.

Typically a thin layer of oil suffices. That's what is (or was) used in mercury barometers, obviously w/ an oil of extremely low partial pressure so as to maintain the desired vacuum in the tube.
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Re: What-If 0050: "Extreme Boating"

Postby cellocgw » Tue Jun 18, 2013 12:40 pm UTC

Showsni wrote:Mostly what I got was "don't use aluminium boats."


Here in the USA we don't use aluminum boats. (you insensitive clod) (except we do, since we tend to do our boating on lakes of water for some strange reason)
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Re: What-If 0050: "Extreme Boating"

Postby elasto » Tue Jun 18, 2013 1:01 pm UTC

Diadem wrote:Stick your hand in a jar of liquid nitrogen, hold it there for half a minute, take out your hand. Admire what is left of your hand.

Is that not a violent reaction?

Yes, it is due to temperature alone, but that doesn't make it any less dangerous. Remember, the word 'reaction' has more meanings that just the chemical one.


If that's what they were referring to they wouldn't specifically say "violent reactions with organic materials"

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Re: What-If 0050: "Extreme Boating"

Postby tibfulv » Tue Jun 18, 2013 1:15 pm UTC

Showsni wrote:Mostly what I got was "don't use aluminium boats."

I also got "don't drink, breathe, rinse your eyes with, or bathe in bromine."

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Re: What-If 0050: "Extreme Boating"

Postby BeerBottle » Tue Jun 18, 2013 1:17 pm UTC

elasto wrote:If that's what they were referring to they wouldn't specifically say "violent reactions with organic materials"
As tups said above, the warning about reaction with organic materials and clothing fires, etc relate to liquid oxygen not nitrogen. Liquid oxygen can by condensed out of air by liquid nitrogen as the latter has a lower boiling point. Nitrogen itself is very inert, especially when so cold. And I agree with tups that this is perhaps cheating, or at least a bit misleading.

When using liquid nitrogen to cool a vacuum trap (used to protect pumps from sucking in organic solvents), it is important not to let air into the trap before removing the liquid nitrogen. Otherwise you may notice your trap full of a nice blue liquid. Take this time either to marvel at the magnetic liquid oxygen you have condensed, perhaps holding a bar magnet up to the side of the flask, or otherwise run for your life as the whole thing is probably just about to explode.

The much more dangerous thing about liquid N2 is asphyxiation. Our bodies react to high levels of CO2 in the air by gagging and spluttering. We have no physical reflex at all to even 100% N2 atmospheres. So if you walk into a room filled with nitrogen you won't notice a thing until you pass out and die. This is why oxygen concentration alarms are mandatory in labs where this could possibly occur.

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Re: What-If 0050: "Extreme Boating"

Postby mathmannix » Tue Jun 18, 2013 1:41 pm UTC

tups wrote:I would like to see the maths that proves me that "it would be impossible to move fast" on a mercury lake. Who calculated this ? The lack of paddle depth may well be compensated by the lack of depth of the boat itself - what are the dynamics governing the rowing process ? Is there an equation for it ?

[etc.]


I don't know much about mercury, but isn't it very slippery = low friction? Couldn't you "row" your boat by merely throwing the oar in the opposite direction and letting Newton's laws of motion handle the rest?
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Re: What-If 0050: "Extreme Boating"

Postby ijuin » Tue Jun 18, 2013 1:45 pm UTC

For rowing the boat in mercury, we could probably use a modified paddle with a flatter blade that will displace less fluid--this would reduce the force needed to push it down into the mercury.

As for the part about the various liquids burning/freezing or suffocating you or being toxic, I was kind of assuming from the get-go that the boater would be wearing some kind of protective space-suit type outfit, which if properly constructed, could probably protect against most of the liquids used in the examples other than the tungsten. Liquid methane lakes, for example, would be found in a Titan-like environment, and a somewhat cooler environment might have liquid nitrogen. Liquid helium however probably would not exist in a natural "sea"-like fluid body anywhere in the universe, since the boiling point of helium is barely higher than the temperature of the cosmic microwave background (i.e. there just won't be anywhere cold enough unless it's being actively kept colder).

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Re: What-If 0050: "Extreme Boating"

Postby tibfulv » Tue Jun 18, 2013 2:18 pm UTC

Thought of something: in Norwegian, a sjark is a type of boat, a small fishing vessel (Link has pics). Apparently the word is derived from the English shark. At least, that's what Wikipedia says ....

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Re: What-If 0050: "Extreme Boating"

Postby BunsenH » Tue Jun 18, 2013 2:58 pm UTC

I was surprised by the stuff about liquid nitrogen reacting with organics or exploding — WTF, Dartmouth? But if you follow the link, the document states clearly that the problem is a result of liquid N2 condensing oxygen from air to create a solution of liquid O2, which is highly reactive.

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Re: What-If 0050: "Extreme Boating"

Postby SemisolidSnake » Tue Jun 18, 2013 3:25 pm UTC

Well, this is timely. I just lost a whole night last week binging on mercury videos from taofledermaus and gallium videos from NurdRage. Throw in Nighthawkinlight and you've got a recipe for being up very late.

I think Randall missed one expensive option for a liquid tungsten container: diamond. I've looked around the internet for a few minutes, and, while not every site agrees, the most common atmospheric melting point for diamond is listed at 3550 deg C. Synthetic diamond creation has advanced to the point where you absolutely could make a tiny diamond crucible for melting tungsten.

Of course, you'd have to melt your tungsten in the presence of an inert since diamond combusts at much lower temperatures than it melts. And....those are the wrong types of engineering questions I'm supposed to be thinking about at this time of day. :)

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Re: What-If 0050: "Extreme Boating"

Postby rhomboidal » Tue Jun 18, 2013 4:02 pm UTC

hehe, I just hope the "third sound" isn't the "brown note."

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Re: What-If 0050: "Extreme Boating"

Postby Vroomfundel » Tue Jun 18, 2013 4:21 pm UTC

Barstro wrote:I just saw that there is an entirely different Thread for What-Ifs. Is there a way for a Moderator to join them, or would other people just keep making What-Ifs in the Individual thread?

If by other people you mean me, who happenened to create them the last two times, then no - I won't be creating further threads here :-) still, what-ifs don't generate nearly enough traffic so our rudimentary discussion here is almost as large as the "official" one

More on point; I'm surprised Randall didn't go into how boats would need different configurations to have correct balance in mercury, etc.

Yes, after the strong start most what-ifs have been kind of half-assed. But I don't blame Randal, this thing really consumes a lot of effort to do right. The good what-ifs are on par with his better blog posts, of which there are only a handful during the whole existance of xkcd.
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Re: What-If 0050: "Extreme Boating"

Postby orthogon » Tue Jun 18, 2013 4:42 pm UTC

phlip wrote:
Tittah wrote:Why should a splashfight in a lake of mercury be avoided? I was taught to believe that liquid mercury is not harmful, even when swallowed.

Less harmful, perhaps. I still wouldn't want to mess with it.

Besides, a splashfight is going to increase the amount of mercury droplets in the air, and generally a greater surface area, which is going to result in more of it being evaporated...


This reminds me of the meme that says that the idea of high voltages being dangerous is a misconception: actually it's currents you should be worried about, ("Volts jolt, but mills kill"). I mean, yes, it's the current flowing through your body that does the damage, but the voltage causes that current. V=IR, and whilst you can increase the danger by bathing in saline, you're not going to change your resistance that much. And most supplies are closer to ideal voltage sources than current sources; even things designed to be current-source-like have limited output voltages, whereas all but the puniest voltage sources can deliver enough current to kill you. Enough voltage is going to kill you however dry you are, and you're never going to get a shock from a car battery, even though it can supply hundreds of amps. (Car batteries are hazardous, of course, like anything that stores a huge amount of energy and is capable of releasing it quickly. They can vaporise metal, explode and/or release large amounts of explosive hydrogen. Sounds like what-if material in itself...)

The point about current is important for understanding the thresholds for RCDs etc., but it's got out of hand as a meme. There's a danger that people insist on unnecessary precautions for low voltages whilst thinking that a 125kV supply really isn't such a big deal after all.

I'm sure that rant had something to do with mercury...
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Re: What-If 0050: "Extreme Boating"

Postby keithl » Tue Jun 18, 2013 5:20 pm UTC

BunsenH wrote:I was surprised by the stuff about liquid nitrogen reacting with organics or exploding — WTF, Dartmouth? But if you follow the link, the document states clearly that the problem is a result of liquid N2 condensing oxygen from air to create a solution of liquid O2, which is highly reactive.


Liquid nitrogen isn't harmless, but it won't condense oxygen from air very fast, not before you can complete your rowboat experiment (breathing supplemental oxygen and wearing something warm). I've used it for cold traps in vacuum systems, and in the insulating outer dewar around a liquid helium dewar (doing superconductivity experiments). Semiconductor factories use LN2 by the tanker-truck load, and have storage tanks big enough to float a boat in (though no doors big enough to get one through).

The big industrial hazard of LN2 is that pressure relief valves can accumulate frost and freeze over. As the LN2 evaporates, the pressure can build inside the tank until it explodes. Not like dynamite, but very loud and throwing chunks. And besides, it wasn't my week to tend the dewar.

It isn't difficult to acquire LN2 for Fun Experiments. An orange dunked in LN2 freezes hard as rock. Drop it and it shatters. Mix flavored cream with LN2 for instant ice cream. A gang of high tech bicycle thieves roamed my university in a truck with a large dewar of LN2 on the back. They would pour a thermos of LN2 on a bike lock chain, create thermal stress, and shatter links with a hammer.

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<troll>

Postby TortoiseWrath » Tue Jun 18, 2013 5:30 pm UTC

It's spelt aluminum.

</troll>

Also, where is the video link in the liquid helium section? It needs one...

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Re: What-If 0050: "Extreme Boating"

Postby lgw » Tue Jun 18, 2013 5:55 pm UTC

There are certainly refractory compounds with a higher melting point than liquid tungsten. Hafnium carbide melts at 3890 C, and tantalum hafnium carbide at over 4200. One could certainly make a container to hold liquid tungsten in a lab. Heck, some XKCD reader has probably done so.
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