I had included an ASCII diagram, but it was rejected as a junk post.
thermal conductivity coefficients:
k [=] W/m deg C
assume 30 deg C
copper (pure) 383
aluminum (pure) 201
so Copper has a value (383 - 201)/383 = 47.5 % higher
> So there are multiple resistances involved in heat transer:
1. CPU internals to CPU exterior surface (internal) (user cannot influence this)
2. CPU to Thermal Paste (interface)
3. Thermal Paste to Heat sink surface (interface)
4. heat transfer within heat sink metal (internal)
5. heat sink to air (interface)
Assumes:
- the use of thermal paste applied as a uniform thin film.
- constant heat duty - chip has been running long enough to be at steady-state temperature.
The heat transfer at (5) is maximized by having a large relative surface area of metal to air transfer area compared with the area of the heat sink in contact with the heat source. By using forced convection (fan) the heat transfer coefficient is increased.
The main improvement by using copper is that the temprature profile along the length of the fin is more uniform, meaning that the same driving force for heat trasfer is maintained, provided a constant heat duty. This produces a smaller temperature at the CPU-Heat Sink interface.
But the interface resistances are most likely a greater factor in the overall heat trasfer - hence the reason why overclockers wetsand the machined interfaces with 220,400,600 grit paper to minimize surface roughness.
I don't have thermal conductivity values for thermal paste - anyone have a k value?
If you're interested, I can provide an example problem from J.P Holman's Heat Transfer with actual values.
Ya know, one or two Penis Bird jokes could be funny. 26 in a day - sounds like you need to check out the large yellow thing when it isn't obscured by clouds.
Ecrix rocks.
The 33/66 GB tapes are pricey, but they should last forever... as the tape does not backhitch (rewind due to lack of data in the stream).
6 MB/sec uncompressed is zippy.
Available in a U2W LVD external config - nice when you decide that one tape drive just won't do, and you want to chain 2 or more for your overall network backup solution.
You see, even if the tank ruptures, the liquid nirtogen still needs heat added to boil the liquid of to vapor. So the liquid wouldn't start to boil until it contacted other matter at ambient temperature, such as the ground - at which point, it would boil off to the atmosphere, not into the car.
An interesting experiment I once saw had a cracker burning in a bowl of liquid oxygen. It did not instantly burn - as liquid oxygen does not support combustion. The oxygen must first be boiled off (requiring heat) for combustion to be possible.
So a flame of several thousand degrees is only millimeters away from pure oxygen in liquid form, yet, no explosion occurs. Fun stuff. Gas phase heat transfer resistances can be quite large.
Liquid Nitrogen (LIN) at atmospheric pressure is indeed dangerous for the following reasons.
1. It can liquify air.
Air liquefaction is one method of obtaining relatively pure Oxygen or Nitrogen. Unfortunaely, liquid oxygen (condensed from air) can be concentrated be leaving exposed metal at LIN's boiling point. If the material contacting the liquified air is not oxygen-enriched compatible, you could have an explosion. Can you said Ford Pinto?
Proper insulation with proper oxygen-clean materials alleviates this concern.
2. It can displace oxygen. (well dilute, really).
If you have a large amount of LIN boiling off, it could lower the concentration of oxygen in the air - possibly making it not capable of supporting respiration. One full inhalation of nitrogen sans oxygen and you're gone. We're not talking whippets here...
The main problem that I see is this: liquid nitrogen is produced via some sort of refridgeration. Refridgeration is produced via a compression/expansion cycle, usually powered by ELECTRICITY. So instead of burning a fossil fuel in the auto engine, the fossil fuel is being burned in a power plant, to produce electricity.
The main reason why I would see it failing is this: to cool down a hose to connect the large tank (filling station) to the car and to cool down the tank + piping requires a relatively large amount of LIN. So much of the finished product is lost in the fueling process.
Another reason for problems is this:
in colder climates, ambient heat exchangers tend to freeze-up, and need to have manual de-icing. Now, an electrical system could include de-icing capabilities, but you must include that as more electricity required in the overall process.
I used to work for one of the few large indutrial gas companies, and spent one morning a month eating donuts, watching safety videos. I also tracked usage of LOX, LIN and LAr (liquid argon) at a research facility in NJ. (Hi Harry).
The point that I would most like to get across is this: instead of selling fuel, it would be selling refridgeration, and boiling off the liquid to generate pressure is the fuel cell.
Compaq offers test drives on 8-way servers for free (registration required). Oracle offers testing on the Internet Appliance Platform for free for Partners.
What do you think about a LUG pooling spare hardware to put together 1 big box (yes, you'll hit the 1 CPU wall) but you need at least 8 hard drives and 1 GB of RAM to really take an Oracle DB out for a run - kinda like never getting above 3500 RPM in third gear.
Oracle 8i Release 2 Standard Edition now supports 4 CPUs. I can't wait until Intel releases their commodity 4-way chipset this spring (too bad AMD can't jump past them on that one).
you're overlooking one detail: overselling of the aggregate bandwith.
Grant me an assumption: consider a basic unit to be a subnet. Lets round it down to 250 for argument's sake. Lets assume its SATURATED.
Okay - in the left corner, 250 DSL users.
- in the right corner, 250 cable users.
So - they're both sharing 30 Mbps on the download, 10 Mbps on the upload.
10240 kbps/250 users = 41 kbps/user
30720 kbps/250 users = 123 kbps/user
So it would appear that the main factor is the amount of overselling/saturation on the subnet. Lots of Napster users on your subnet, and you're screwed. I'm actually glad that they instituted the upload cap - just don't try to email anything while downloading.
I already had purchased a copy of Quake III Arena for Win32, but when I saw the Tin Box at LinuxCentral's booth just around the corner from the Loki booth - I couldn't resist.
Now, I don't actually use it for playing the desktop version, but I do run the server version on my Linux box.
I found a Dell 410 Precision Workstation on UBid when Ubid first opened. Dual capable, onboard U2W and UW SCSI. Just over $1000.00. It shipped with only a PII 350 and 128 MB RAM (ECC). Now its a PIII 550 with a Voodoo 3 3000 and 4 hard drives - JBOD. I'm thinking about adding the RAIDport card to it. I have the same box at work - running a single 4 drive RAID 0 array, dual PII 400's.
It gets backed up entirely every week, important stuff every night. One drive dies, the array dies.
Fuck RAID 5. RAID 0+1 rocks for servers, but is too expensive for a workstation.
RAID 0 4 drives deep on Ultra2Wide SCSI with a 16 MB cache ROCKS! The problem is that you can't dual boot very easily on such drive configurations.
So after I wipe it for the RAID controller, it will have one OS as a base, and VMWare for all the other ones.
had a single PII 350. bought a pair of PIII 550's on ebay for $290. have 2 break out the soldering gun to get power to the fans, though. Now my P5 166 linux box will be a PII 337 (LX motherboard that I had will run at 75 MHz).
It sounds like a real trade-off: signal strength vs. possible health effects.
Filters, or filterless? Chooose yer poison.
My guess is this: adaptations will be made. Take for instance the earpiece/microphone attachments. These put the base unit in your pocket. Those components could be made wireless, only having to transmit a strong enough signal to be picked up by the base unit and amplified to hit a tower/satellite.
I'll bet that the 1st generation of TVs would cook a TV dinner in under an hour...
Re:Already being done - Thanks for the link
on
Pirate DNS?
·
· Score: 1
Hi. I just grabbed good.beer [.xs2.net] for free for the first year. Call me a squatter, but if the right person asks for it with good intentions, I"d part with it in an hour...
Have they also throught about archiving some of the more influential (developer) mailing lists? Yes, there are websites that carrry archives of some mailing lists - will those be archived also? I'm not talking about high-volume, low quality, newbie-filled lists but the developer-oriented lists could prove to be interesting...
Slashdot Mirror
You might want to investigate the use of an AT command from either the local machine, or from another user on the network that has domain admin.
/?" at a command prompt.
It could actually be a *malicious user* (LOL) on the network that is remotely rebooting your collegues machine, at least part of the time.
try "shutdown
cool. now all that has to be estimated is the net roughness of both surfaces to obtain the average thickness of the thermal paste.
I had included an ASCII diagram, but it was rejected as a junk post.
thermal conductivity coefficients:
k [=] W/m deg C
assume 30 deg C
copper (pure) 383
aluminum (pure) 201
so Copper has a value (383 - 201)/383 = 47.5 % higher
>
So there are multiple resistances involved in heat transer:
1. CPU internals to CPU exterior surface (internal) (user cannot influence this)
2. CPU to Thermal Paste (interface)
3. Thermal Paste to Heat sink surface (interface)
4. heat transfer within heat sink metal (internal)
5. heat sink to air (interface)
Assumes:
- the use of thermal paste applied as a uniform thin film.
- constant heat duty - chip has been running long enough to be at steady-state temperature.
The heat transfer at (5) is maximized by having a large relative surface area of metal to air transfer area compared with the area of the heat sink in contact with the heat source. By using forced convection (fan) the heat transfer coefficient is increased.
The main improvement by using copper is that the temprature profile along the length of the fin is more uniform, meaning that the same driving force for heat trasfer is maintained, provided a constant heat duty. This produces a smaller temperature at the CPU-Heat Sink interface.
But the interface resistances are most likely a greater factor in the overall heat trasfer - hence the reason why overclockers wetsand the machined interfaces with 220,400,600 grit paper to minimize surface roughness.
I don't have thermal conductivity values for thermal paste - anyone have a k value?
If you're interested, I can provide an example problem from J.P Holman's Heat Transfer with actual values.
Ya know, one or two Penis Bird jokes could be funny. 26 in a day - sounds like you need to check out the large yellow thing when it isn't obscured by clouds.
Anyone on staff at Slashdot over this weekend:
bounce that fscking moron that insists upon loading your site with the kind of crap that makes me have to view at +2.
take back you site.
thanks.
Ecrix rocks. ... as the tape does not backhitch (rewind due to lack of data in the stream).
The 33/66 GB tapes are pricey, but they should last forever
6 MB/sec uncompressed is zippy.
Available in a U2W LVD external config - nice when you decide that one tape drive just won't do, and you want to chain 2 or more for your overall network backup solution.
Oracle User account - SYS
password: change_on_install
I think that Oracle covered their ass on that one.
rupture of tank != explosion.
You see, even if the tank ruptures, the liquid nirtogen still needs heat added to boil the liquid of to vapor. So the liquid wouldn't start to boil until it contacted other matter at ambient temperature, such as the ground - at which point, it would boil off to the atmosphere, not into the car.
An interesting experiment I once saw had a cracker burning in a bowl of liquid oxygen. It did not instantly burn - as liquid oxygen does not support combustion. The oxygen must first be boiled off (requiring heat) for combustion to be possible.
So a flame of several thousand degrees is only millimeters away from pure oxygen in liquid form, yet, no explosion occurs. Fun stuff. Gas phase heat transfer resistances can be quite large.
Liquid Nitrogen (LIN) at atmospheric pressure is indeed dangerous for the following reasons.
...
1. It can liquify air.
Air liquefaction is one method of obtaining relatively pure Oxygen or Nitrogen. Unfortunaely, liquid oxygen (condensed from air) can be concentrated be leaving exposed metal at LIN's boiling point. If the material contacting the liquified air is not oxygen-enriched compatible, you could have an explosion. Can you said Ford Pinto?
Proper insulation with proper oxygen-clean materials alleviates this concern.
2. It can displace oxygen. (well dilute, really).
If you have a large amount of LIN boiling off, it could lower the concentration of oxygen in the air - possibly making it not capable of supporting respiration. One full inhalation of nitrogen sans oxygen and you're gone. We're not talking whippets here
The main problem that I see is this: liquid nitrogen is produced via some sort of refridgeration. Refridgeration is produced via a compression/expansion cycle, usually powered by ELECTRICITY. So instead of burning a fossil fuel in the auto engine, the fossil fuel is being burned in a power plant, to produce electricity.
The main reason why I would see it failing is this: to cool down a hose to connect the large tank (filling station) to the car and to cool down the tank + piping requires a relatively large amount of LIN. So much of the finished product is lost in the fueling process.
Another reason for problems is this:
in colder climates, ambient heat exchangers tend to freeze-up, and need to have manual de-icing. Now, an electrical system could include de-icing capabilities, but you must include that as more electricity required in the overall process.
I used to work for one of the few large indutrial gas companies, and spent one morning a month eating donuts, watching safety videos. I also tracked usage of LOX, LIN and LAr (liquid argon) at a research facility in NJ. (Hi Harry).
The point that I would most like to get across is this: instead of selling fuel, it would be selling refridgeration, and boiling off the liquid to generate pressure is the fuel cell.
Compaq offers test drives on 8-way servers for free (registration required). Oracle offers testing on the Internet Appliance Platform for free for Partners.
What do you think about a LUG pooling spare hardware to put together 1 big box (yes, you'll hit the 1 CPU wall) but you need at least 8 hard drives and 1 GB of RAM to really take an Oracle DB out for a run - kinda like never getting above 3500 RPM in third gear.
Oracle 8i Release 2 Standard Edition now supports 4 CPUs. I can't wait until Intel releases their commodity 4-way chipset this spring (too bad AMD can't jump past them on that one).
3 letters: RBL
you're overlooking one detail: overselling of the aggregate bandwith.
Grant me an assumption: consider a basic unit to be a subnet. Lets round it down to 250 for argument's sake. Lets assume its SATURATED.
Okay - in the left corner, 250 DSL users.
- in the right corner, 250 cable users.
So - they're both sharing 30 Mbps on the download, 10 Mbps on the upload.
10240 kbps/250 users = 41 kbps/user
30720 kbps/250 users = 123 kbps/user
So it would appear that the main factor is the amount of overselling/saturation on the subnet. Lots of Napster users on your subnet, and you're screwed. I'm actually glad that they instituted the upload cap - just don't try to email anything while downloading.
Yeah, but the VPN services might get blocked - hence this entire thread!
@Home would have more bandwith that they could shovel if they just follwed through on abuse reports.
...
those little fuckers are always knocking
I already had purchased a copy of Quake III Arena for Win32, but when I saw the Tin Box at LinuxCentral's booth just around the corner from the Loki booth - I couldn't resist.
Now, I don't actually use it for playing the desktop version, but I do run the server version on my Linux box.
Vote with you $$$$.
I found a Dell 410 Precision Workstation on UBid when Ubid first opened. Dual capable, onboard U2W and UW SCSI. Just over $1000.00. It shipped with only a PII 350 and 128 MB RAM (ECC). Now its a PIII 550 with a Voodoo 3 3000 and 4 hard drives - JBOD. I'm thinking about adding the RAIDport card to it. I have the same box at work - running a single 4 drive RAID 0 array, dual PII 400's.
It gets backed up entirely every week, important stuff every night. One drive dies, the array dies.
Fuck RAID 5. RAID 0+1 rocks for servers, but is too expensive for a workstation.
RAID 0 4 drives deep on Ultra2Wide SCSI with a 16 MB cache ROCKS! The problem is that you can't dual boot very easily on such drive configurations.
So after I wipe it for the RAID controller, it will have one OS as a base, and VMWare for all the other ones.
Too bad the BIOS couldn't access the site ... but then again, a new BIOS is only a boot floppy away.
had a single PII 350.
bought a pair of PIII 550's on ebay for $290.
have 2 break out the soldering gun to get power to the fans, though.
Now my P5 166 linux box will be a PII 337 (LX motherboard that I had will run at 75 MHz).
apologies for a lame attempt at a first post.
...
It sounds like a real trade-off:
signal strength vs. possible health effects.
Filters, or filterless? Chooose yer poison.
My guess is this: adaptations will be made.
Take for instance the earpiece/microphone attachments. These put the base unit in your pocket. Those components could be made wireless, only having to transmit a strong enough signal to be picked up by the base unit and amplified to hit a tower/satellite.
I'll bet that the 1st generation of TVs would cook a TV dinner in under an hour
http://www.linuxtelephony.com/
is a good place to start.
Hi. ...
I just grabbed good.beer [.xs2.net] for free for the first year. Call me a squatter, but if the right person asks for it with good intentions, I"d part with it in an hour
Have they also throught about archiving some of the more influential (developer) mailing lists? ...
Yes, there are websites that carrry archives of some mailing lists - will those be archived also?
I'm not talking about high-volume, low quality, newbie-filled lists but the developer-oriented lists could prove to be interesting
Yes, we need the ads.
That way, when we're outfitted with clothes for backward time travel, we won't look like Austin Powers.
Sounds like an excuse for having the worlds largest pr0n collection 8^)
"Stuff like this makes me wish I lived in the valley." One in NYC soon - check with NYLUG for details. Pd