search results matching tag: Ignition

» channel: learn

go advanced with your query
Search took 0.000 seconds

    Videos (160)     Sift Talk (2)     Blogs (7)     Comments (302)   

blankfist (Member Profile)

BoneRemake says...

Autoignition temperature
From Wikipedia, the free encyclopedia

The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark. This temperature is required to supply the activation energy needed for combustion. The temperature at which a chemical will ignite decreases as the pressure increases or oxygen concentration increases. It is usually applied to a combustible fuel mixture.

Autoignition temperatures of liquid chemicals are typically measured using a 500 mL flask placed in a temperature controlled oven in accordance with the procedure described in ASTM E659.[1]
Contents
[hide]

1 Autoignition equation
2 Autoignition point of selected substances
3 See also
4 References
5 External links

[edit] Autoignition equation

The time t_{ig}\, it takes for a material to reach its autoignition temperature T_{ig}\, when exposed to a heat flux q''\, is given by the following equation

t_{ig} = \left ( \frac{\pi}{4} \right ) \left (k \rho c \right )\left [ \frac{T_{ig}-T_{o}}{q''} \right]^2 [2]

where k = thermal conductivity (W/(m·K)), ρ = density (kg/m³), and c = specific heat capacity (J/(kg·K)) of the material of interest. T_{o}\, is the temperature, in kelvins, the material starts at (or the temperature of the bulk material), and q''\, is the heat flux (W/m²) incident to the material.

To be consistent in units the group \left[ \frac{T_{ig}-T_{o}}{q''} \right] should be squared.

How Things Björk

Boise_Lib says...

>> ^drk421:

>> ^Boise_Lib:
The capacitors aren't the problem as stated above. The CRT itself is a very large capacitor (stores charge) and can knock you on your ass for a long time after the tv is unplugged.
Also, she's weird.

Yeah, my old boss got shocked by the CRT discharge and his arm swung against the side of the wall and he got cut really bad. It has about the same effect has getting shocked by an ignition coil from a car. I had a similar situation while working on a tube amplifier (around 600V).
High voltage DC will basically burn you really bad (provided it has enough current), but unless you have heart condition it probably won't kill you. It will defibrillate you and wake you up though.
High voltage low frequency AC (between 30 and 1000hz) is deadly starting at around 45 volts. As you get into the higher frequency AC voltages it has less affect on your heart, and thus less likely to kill you.


I saw a chart once in physics class that showed the lethality vs. frequency of AC. The peak was at 50 Hz--right where Europe put their power supply.

I got bit by 277VAC 50Hz once--burned a 1/2 inch hole 1/4 inch deep in my arm.
(I wish we had the metric system in the old USA)

How Things Björk

drk421 says...

>> ^Boise_Lib:

The capacitors aren't the problem as stated above. The CRT itself is a very large capacitor (stores charge) and can knock you on your ass for a long time after the tv is unplugged.
Also, she's weird.


Yeah, my old boss got shocked by the CRT discharge and his arm swung against the side of the wall and he got cut really bad. It has about the same effect has getting shocked by an ignition coil from a car. I had a similar situation while working on a tube amplifier (around 600V).

High voltage DC will basically burn you really bad (provided it has enough current), but unless you have heart condition it probably won't kill you. It will defibrillate you and wake you up though.

High voltage low frequency AC (between 30 and 1000hz) is deadly starting at around 45 volts. As you get into the higher frequency AC voltages it has less affect on your heart, and thus less likely to kill you.

"Building 7" Explained

Fade says...

Because it's simple physics that no steel skyscraper has ever collapsed from, before and since.>> ^coolhund:

Oh man guys...
It has been said for years, and you can also go ask your local firefighters (DO IT!!!!!!!!!): Fires in closed rooms, especially office fires, can easily reach 1000C and far above that. It even gets so hot that the gas thats created from the fire itself will ignite aswell, creating even higher temperatures!!!
Seriously... Its simple physics. I really dont understand why people still question it...

"Building 7" Explained

coolhund says...

Oh man guys...
It has been said for years, and you can also go ask your local firefighters (DO IT!!!!!!!!!): Fires in closed rooms, especially office fires, can easily reach 1000C and far above that. It even gets so hot that the gas thats created from the fire itself will ignite aswell, creating even higher temperatures!!!

Seriously... Its simple physics. I really dont understand why people still question it...

ssssSSSsssssSSSSSSssss...PHEWWWWWWWM !

BoneRemake says...

>> ^bareboards2:

Was that on purpose??????


Not the fire that started on the ground causing everyone to start running for life.

My brother explained it to me somewhat, there was liquid fuel in the lines and when they opened up the valve to start the flare stack thus supplying it with the fuel source ( vapor to be burned). That liquid is from a fuckup of theirs as the fuel condensed in the lines and was pushed out by the vapor and it landed causing pools and the flare was shooting out globs of liquid on fire and it fell onto the ground lighting the pools of fuel on fire.

THIS is how ya learn the hard way

"Building 7" Explained

Payback says...

>> ^marinara:

Exactly how does some office furniture burn for 7 hours, and then raise (fireproofed) steel to over 1000 degrees? What we know from other videos of WT7, is many of the fires extinguished themselves (burned themselves out).

I really doubt that a failure of a steel beam, which supports the floor (and nothing else), could take down an entire building.
Otherwise the facts in this video are generally correct, but misleading. (because office fires don't burn over 1000 degrees)


Actually, cinder blocks will ignite and burn if hot enough and they make up most people's chimneys in their house. Different materials burn at higher and higher temperatures. The heat from the fire pulls in more air, which causes higher temp things to burn, which pulls in more air, etc. etc.

ANY large fire can burn over 1000 degrees. It just needs oxygen in quantity. If some sweaty bastard with a set of bellows can melt iron and steel in a forge, then air sucked in by a huge, uncontrolled fire can do the same. The whole structure doesn't need to bend, just parts of the bottom.

You can't equate a single-room fire test of material combustion with a fully involved structure fire.

...and yes, you are quite right, most fires, if not brought under control, make highrises into death traps.

Revving it! And Revving And Revving And Revving AND

Orthodox Jews Serenade Sabbath Workers

newtboy says...

I disagree and here's why, since the Jews have a religious state, and that state supports these fanatics financially and militarily, ALL Jews (or at least all Israelites and Zionists, and sadly all American tax payers since we send them billions of our tax dollars) support these fanatics, and should be lumped in with them until they stop their blind support for dangerous, fanatical religious zealots. Remember, these are the people still settling in the agreed on Palestinian held areas and then getting military support to keep their freshly stolen property, and Israel refuses to stop supporting the 'settlers' (which should rightly be called 'invaders').
Why doesn't the US, as a supporter of Israel and a believer in borders, tell them to stop expanding into their neighbors territories? I just don't understand OUR support of THEIR expansionist agenda at all.
Side note: If your 'god' gives you the right to take from others or hurt others, your 'god' is evil, and so are you. If your 'god' gives you the right to harass and terrorize others, your 'god' and religion are terroristic. I think this holds water for every religion that allows prostelatizing or demands adherence to their 'rules' by non-believers, they are all terroristic to those not part of their group to some degree.

>> ^mxxcon:
>> ^newtboy:
...and of course, forcing their religion on others is not considered 'controlling one's environment'. This is typical of religious nutjobs, it's the 'god made these rules, everyone must follow them, regardless of your religion, unless they interfere with what me and my kind want to do, then YOU must continue to follow MY religious rules while I may do what I want' mindset...and they wonder why there's rampant anti semitism in the world, they should maybe try some self examination before passing their skewed judgement on everyone else.
Why are we sending these nutjobs our tax dollars? Can anyone possibly give me a reasonable explanation for this beyond 'they're are friends'? If they can't survive on their own in the land they stole, perhaps they should leave.
>> ^xxovercastxx:
>> ^Nexxus:
I don't see 'operating a pallet jack' on that list.
>> ^xxovercastxx:
If you're curious what is actually forbidden during Shabbat, here's a list on wikipedia: http://en.wikipedia.org/wiki/Activities_prohibited_on_Shabbat
#9 is sifting so there better not be any new videos next weekend.


This sort of thing would be forbidden as "Transferring between domains". Driving the truck would also be forbidden as it violates "Igniting a fire". Some would also argue that it violates the spirit of the law as it is controlling one's environment, which is what all of these rules are meant to forbid.

well, antisemitism affects all Jews, where as these are some of the more 'hardcore' fanatics. just like you shouldn't equate terrorists to all Christians or Muslims.

Orthodox Jews Serenade Sabbath Workers

mxxcon says...

>> ^newtboy:

...and of course, forcing their religion on others is not considered 'controlling one's environment'. This is typical of religious nutjobs, it's the 'god made these rules, everyone must follow them, regardless of your religion, unless they interfere with what me and my kind want to do, then YOU must continue to follow MY religious rules while I may do what I want' mindset...and they wonder why there's rampant anti semitism in the world, they should maybe try some self examination before passing their skewed judgement on everyone else.
Why are we sending these nutjobs our tax dollars? Can anyone possibly give me a reasonable explanation for this beyond 'they're are friends'? If they can't survive on their own in the land they stole, perhaps they should leave.
>> ^xxovercastxx:
>> ^Nexxus:
I don't see 'operating a pallet jack' on that list.
>> ^xxovercastxx:
If you're curious what is actually forbidden during Shabbat, here's a list on wikipedia: http://en.wikipedia.org/wiki/Activities_prohibited_on_Shabbat
#9 is sifting so there better not be any new videos next weekend.


This sort of thing would be forbidden as "Transferring between domains". Driving the truck would also be forbidden as it violates "Igniting a fire". Some would also argue that it violates the spirit of the law as it is controlling one's environment, which is what all of these rules are meant to forbid.

well, antisemitism affects all Jews, where as these are some of the more 'hardcore' fanatics. just like you shouldn't equate terrorists to all Christians or Muslims.

Orthodox Jews Serenade Sabbath Workers

newtboy says...

...and of course, forcing their religion on others is not considered 'controlling one's environment'. This is typical of religious nutjobs, it's the 'god made these rules, everyone must follow them, regardless of your religion, unless they interfere with what me and my kind want to do, then YOU must continue to follow MY religious rules while I may do what I want' mindset...and they wonder why there's rampant anti semitism in the world, they should maybe try some self examination before passing their skewed judgement on everyone else.
Why are we sending these nutjobs our tax dollars? Can anyone possibly give me a reasonable explanation for this beyond 'they're are friends'? If they can't survive on their own in the land they stole, perhaps they should leave.
>> ^xxovercastxx:
>> ^Nexxus:
I don't see 'operating a pallet jack' on that list.
>> ^xxovercastxx:
If you're curious what is actually forbidden during Shabbat, here's a list on wikipedia: http://en.wikipedia.org/wiki/Activities_prohibited_on_Shabbat
#9 is sifting so there better not be any new videos next weekend.


This sort of thing would be forbidden as "Transferring between domains". Driving the truck would also be forbidden as it violates "Igniting a fire". Some would also argue that it violates the spirit of the law as it is controlling one's environment, which is what all of these rules are meant to forbid.

Orthodox Jews Serenade Sabbath Workers

xxovercastxx says...

>> ^Nexxus:

I don't see 'operating a pallet jack' on that list.
>> ^xxovercastxx:
If you're curious what is actually forbidden during Shabbat, here's a list on wikipedia: http://en.wikipedia.org/wiki/Activities_prohibited_on_Shabbat
#9 is sifting so there better not be any new videos next weekend.



This sort of thing would be forbidden as "Transferring between domains". Driving the truck would also be forbidden as it violates "Igniting a fire". Some would also argue that it violates the spirit of the law as it is controlling one's environment, which is what all of these rules are meant to forbid.

Addicted (to this Universal Feeling Called Life)

eric3579 says...

I was born in the 80's with that summertime love
Then changed the whole game like whatever I'd done
Out the gutter I come to touch the bright sun
And from the highest heights motherf@#cker I jumped

Free in the sky of belief I can fly,
Ain't no tellin what they're sellin man
They're sheep in disguise
Keep this in mind, I keep on my grind
I can do it any way I wanna do it and
B!tch I'll sleep when I die

Explosive, ferocious, get up get down that's showbiz
Power to the people that have freedom in their focus
I hope this helps you when your under the thumb
When you feel like nothing can save you
When you feel like jumpin the gun

Stop relax and remember even in the worst weather
You'll find a way across it
There'll be brighter days honest
So get up, get out and get somethin that's on the real
Forget what you were taught
And show these people how you feel like

Chorus
Who are you to tell me how to live my life (my life)
Cause I won't give this up,
These are my shoes, my view, my cue
To say I do give a f@#ck
And pretty soon Imma bloomin it'll be alright
Everyday's another chance to ignite
Cause I'm addicted (o-Oh)
I'm addicted (o-Oh)
I'm addicted to this universal feelin called life

.......

Yeah since a foetus, explored life's subtle secrets
From my fingertips to my unique double helix
I can see history, I can see the past lessons
It's your right never be afraid to ask questions

How can every religion, claim to be the only one
How can they preach love
Yet fight each other holding guns
I think the golden sun may be able to shed some light
I'd rather push peace and knowledge to defend our right

These leaders in suits tell us to fight for one side
You think they got their sons and daughters on the frontline?
Not down for war but down to get an education
we're all evil yet they push synthetic separation
But in this matrix I won't be failin to make it
This is my cosmos baby space sailin with Satan
I heard it's not where your from
It's where your carvin' your view
I heard you don't have to wear a suit
To argue the truth and so

Chorus
Who are you to tell me how to live my life (my life)
Cause I won't give this up
These are my shoes, my view, my cue
To say I do give a f@#ck
And pretty soon I'ma bloomin it'll be alright
Everyday's another chance to ignite
Cause I'm addicted (oh-Oh)
I'm addicted (oh-Oh)
I'm addicted to this universal feelin called life

Chorus
Who are you to tell me how to live my life (my life)
Cause I won't give this up
These are my shoes, my view, my cue
To say I do give a f@#ck
And pretty soon I'ma bloomin it'll be alright
Everyday's another chance to ignite
Cause I'm addicted (oh-Oh)
I'm addicted (oh-Oh)
I'm addicted to this universal feelin called life

Slow-motion oil fire -- don't pour water into hot oil!

Team Fortress 2: Guide to the Pyro's Compression Blast Gun



Send this Article to a Friend



Separate multiple emails with a comma (,); limit 5 recipients






Your email has been sent successfully!

Manage this Video in Your Playlists

Beggar's Canyon