Funny how the English are complaining about camera phones when they were one of the first to place the entire downtown core of a city under continuous video surveilance!
Fire up seti@home on both CPU's, and the power consumption goes up to almost 400 watts. There's also a significant increase in heat output, but I can't quantify that.
Since the power going into the system must end up in a form that "Could be Used to Lift a Weight," we can see that most of those 400W go to such things as Heat, Sound, and Hard Drive Operation. Sound and HDD power usage are minimal (let's say 10W) this leaves a heat generation of 390W.
Keep in mind, this 390W isn't added to the previous 400W consumption, it's the same power we're talking about.
If you're server room is sealed and even moderately insulated (windows and suspended ceiling) it'll probably be cooled by an a/c unit. A rough guess of 30% efficiency on that would give you 500W (390*1.30=507) needed to actually move that heat FROM the server room to some outside place.
Total peak power lost to heat and dealing with heat in this example: Power for A/C + Power for Computer = 500W + 400W = 900W
How can you reduce these power costs? It's hard to say without knowing details, but the only solution i see is to relocate your office toaster ovens to the server room, and maybe you can re-use the waste hear to pre-heat the ovens:-P
Firstly, it's disappointing to see the parent post modded 5, when most of that was discussed in my previous post. Of course, I'm not pointing a finger at you DarkBlackFox.
How about momentum and gravity going down a hill?
This falls under regenerative breaking, and was discussed in my previous post.
If I'm not mistaken, internal combustion engines are far more practical for automobiles than electric motors (given efficiencies, torque/speed curves, etc, although I'm not entirely sure how hydrogen engines compare to gasoline on this front)
Electric motors provide maximum torque at 0rpm, this is ideal for automobiles. Furthermore, they require no gearboxes (not a plus for us manual transmisson lovers, but it's a big benefit for automatic transmission users).
but it's interesting to see electric energy applied towards generating fuel for combustion, rather than electromechanical motion.
The use of hydrogen for combustion is missing the big point of hydrogen fuel. You can pass it through a fuel cell creating only water as a byproduct, whereas using it in combustion still creates NOx. Furthermore, it is also more efficient to use a fuel cell, as explained here: In stark comparison, fuel cells running on pure hydrogen are dramatically more efficient. By harnessing the fuel's energy via a chemical reaction rather than combustion, a fuel cell can convert 40-65% of hydrogen's energy into electricity. While a hydrogen-burning IC engine pollutes less than one running on gasoline, its energy efficiency is still less than half that of a fuel cell.
My question then becomes, how much hydrogen can be produced using the amount of power stored in batteries in current hybrid/electric cars?
Not very much. Inefficiencies would make this a ludicrous method to power a vehicle. Furthermore, hydrogen is best used in a fuel cell, not in combustion. Fuel cells are used to run electric motors, and hence, it's advantageous to not use batteries to electrolyse hydrogen only to use that hydrogen in the production of electricity again.
Imagine running out of gas, where all you have to do is wait a bit for the sun to do it's thing, or unpack a stationary bike and pedal for a while until you have enough hydrogen to get on your way. Or how about using an alternator to continuously generate power as the vehicle is moving
HAH! If you were counting on a stationary bike to do the job, you might as well dump your inefficient car and bike your way to where you're going!
Where's the alternator gonna get it's power from? Majick? LOL, any energy spent turning the alernator would have to come from the engine, and hence from the original hydrogen. Regenerative braking is an option, but the amount of power recovered from that does not warrant puting in an electrolyzer in the car, batteries would do the trick.
Give me distorted third and fourth hand information any day....now they're posting articles from the sources. What's next, original news content?
Generally, readers prefer information from "the source".
I think people come to slashdot because the posted topics (the good ones) have some analysis or research in them. Xamlon's "shameless plug" is technically allowable, but it provides no insight into the matter other than their own narrow opinion. If, for example, they were to include links to competitors products or previous developments in the same area, then it would be a fully excelent post. But when a developer posts only their own information, it is disrespectful to the Slashdot process and to Slashdot Readers.
Most of the blame should go to the editor who lets this slop get through, though, since anyone can submit crap, but it's the editor's job to ensure the "Slashdot process" and Slashdot's public image are upheld.
Security Problems? Buffer overruns?
on
How to Podcast
·
· Score: 3, Interesting
Might this open up some security problems?
iPodderX, which is basically a newsreader that reads RSS 2.0 feeds with enclosures, takes those enclosures and automatically downloads them in the background. If the file is an audio file, it then moves it to iTunes for download to your iPod, so with iPodderX you constantly have fresh content to listen to. iPodderX downloads any type of file, (even Torrents) so you can wake up in the morning with a fresh set of audio shows, video programs, or whatever else you've subscribed to.
What if someone were to take advantage of these auto downloads and use them to send you infected files. Maybe there are problems in iTunes' coding that will allow buffer overruns like those found with JPGs?
V-Chat was a program from about 1999 where you could hover around as a sprite based avatar in a bland 3D world. It was really just like IRC but with a 3d area to walk around.
One plus with this program was that you could make your own avatars, upload them to your personal web space, and link to them from the client. Voila! Everybody saw your custom avatar for free. The saddest thing was that people made humps with eachother by walking up to them and ducking and standing repeatedly... i know from experience
For those of us with Tablet PCs, MSN Messenger automatically offers ink as an option for chatting. All MSN Messenger users with a new-enough (ver 5+, i think) version of the program can see the ink.
By the way, does anybody ever remember the 3d webbrowsers? They never seemed to get popular at all, and they were usually free!
Sorry about that, I didn't realise you were talking about the speed when the outside edge was being read. The way it was originally written made me think someone was stupid enough to think RPMs varied across the disk at any one particular instance in time.
The angular velocity, as measured sometimes by RPM, is CONSTANT over a rigid body. If your DVDs are experiencing different RPMs at the ourside edge than at the centre then i'd strongly suggest laying off the goofballs.
Following his success in writing a book on Project Automation Dave Thomas decided he'd share his knowledge of Pragmatic Patty Production with the world.
In this tell all exposee of beefly manufacturing processes, he teaches the enthralled reader how to use common, freely available tools to automate build, test, and release highly beeftacular burgers at a fraction of the current cost!
Slashdot Mirror
"We need more Bort license plates in the gift shop. I repeat, we are sold out of Bort license plates."
I won't beleive it untill netcraft has confirmed it.
Funny how the English are complaining about camera phones when they were one of the first to place the entire downtown core of a city under continuous video surveilance!
some more info here
here is wikipedia in Lojban
It's not google's fault that other programs leave data out in the open. The search tool does nothing a regular user couldn't do!
What these game companies should do is sell ad-subsidized games. Full price: No ads. Super discount price: Ads galore. Much like Eudora or Opera.
Fire up seti@home on both CPU's, and the power consumption goes up to almost 400 watts. There's also a significant increase in heat output, but I can't quantify that.
:-P
Since the power going into the system must end up in a form that "Could be Used to Lift a Weight," we can see that most of those 400W go to such things as Heat, Sound, and Hard Drive Operation. Sound and HDD power usage are minimal (let's say 10W) this leaves a heat generation of 390W.
Keep in mind, this 390W isn't added to the previous 400W consumption, it's the same power we're talking about.
If you're server room is sealed and even moderately insulated (windows and suspended ceiling) it'll probably be cooled by an a/c unit. A rough guess of 30% efficiency on that would give you 500W (390*1.30=507) needed to actually move that heat FROM the server room to some outside place.
Total peak power lost to heat and dealing with heat in this example: Power for A/C + Power for Computer = 500W + 400W = 900W
How can you reduce these power costs? It's hard to say without knowing details, but the only solution i see is to relocate your office toaster ovens to the server room, and maybe you can re-use the waste hear to pre-heat the ovens
Two steps ahead of you, chief:
Budweiser Debuts Caffeinated Beer
Firstly, it's disappointing to see the parent post modded 5, when most of that was discussed in my previous post. Of course, I'm not pointing a finger at you DarkBlackFox.
How about momentum and gravity going down a hill?
This falls under regenerative breaking, and was discussed in my previous post.
If I'm not mistaken, internal combustion engines are far more practical for automobiles than electric motors (given efficiencies, torque/speed curves, etc, although I'm not entirely sure how hydrogen engines compare to gasoline on this front)
Electric motors provide maximum torque at 0rpm, this is ideal for automobiles. Furthermore, they require no gearboxes (not a plus for us manual transmisson lovers, but it's a big benefit for automatic transmission users).
but it's interesting to see electric energy applied towards generating fuel for combustion, rather than electromechanical motion.
The use of hydrogen for combustion is missing the big point of hydrogen fuel. You can pass it through a fuel cell creating only water as a byproduct, whereas using it in combustion still creates NOx. Furthermore, it is also more efficient to use a fuel cell, as explained here:
In stark comparison, fuel cells running on pure hydrogen are dramatically more efficient. By harnessing the fuel's energy via a chemical reaction rather than combustion, a fuel cell can convert 40-65% of hydrogen's energy into electricity. While a hydrogen-burning IC engine pollutes less than one running on gasoline, its energy efficiency is still less than half that of a fuel cell.
My question then becomes, how much hydrogen can be produced using the amount of power stored in batteries in current hybrid/electric cars?
Not very much. Inefficiencies would make this a ludicrous method to power a vehicle. Furthermore, hydrogen is best used in a fuel cell, not in combustion. Fuel cells are used to run electric motors, and hence, it's advantageous to not use batteries to electrolyse hydrogen only to use that hydrogen in the production of electricity again.
err: I, for one, welcome our new cheap 32-bit microcontroller overlords
I, for one, welcome our new 32-bit microcontroller overlords.
Imagine running out of gas, where all you have to do is wait a bit for the sun to do it's thing, or unpack a stationary bike and pedal for a while until you have enough hydrogen to get on your way. Or how about using an alternator to continuously generate power as the vehicle is moving
HAH! If you were counting on a stationary bike to do the job, you might as well dump your inefficient car and bike your way to where you're going!
Where's the alternator gonna get it's power from? Majick? LOL, any energy spent turning the alernator would have to come from the engine, and hence from the original hydrogen. Regenerative braking is an option, but the amount of power recovered from that does not warrant puting in an electrolyzer in the car, batteries would do the trick.
Give me distorted third and fourth hand information any day. ...now they're posting articles from the sources. What's next, original news content?
Generally, readers prefer information from "the source".
I think people come to slashdot because the posted topics (the good ones) have some analysis or research in them.
Xamlon's "shameless plug" is technically allowable, but it provides no insight into the matter other than their own narrow opinion. If, for example, they were to include links to competitors products or previous developments in the same area, then it would be a fully excelent post. But when a developer posts only their own information, it is disrespectful to the Slashdot process and to Slashdot Readers.
Most of the blame should go to the editor who lets this slop get through, though, since anyone can submit crap, but it's the editor's job to ensure the "Slashdot process" and Slashdot's public image are upheld.
Might this open up some security problems?
iPodderX, which is basically a newsreader that reads RSS 2.0 feeds with enclosures, takes those enclosures and automatically downloads them in the background. If the file is an audio file, it then moves it to iTunes for download to your iPod, so with iPodderX you constantly have fresh content to listen to. iPodderX downloads any type of file, (even Torrents) so you can wake up in the morning with a fresh set of audio shows, video programs, or whatever else you've subscribed to.
What if someone were to take advantage of these auto downloads and use them to send you infected files. Maybe there are problems in iTunes' coding that will allow buffer overruns like those found with JPGs?
V-Chat was a program from about 1999 where you could hover around as a sprite based avatar in a bland 3D world. It was really just like IRC but with a 3d area to walk around.
One plus with this program was that you could make your own avatars, upload them to your personal web space, and link to them from the client. Voila! Everybody saw your custom avatar for free. The saddest thing was that people made humps with eachother by walking up to them and ducking and standing repeatedly... i know from experience
For those of us with Tablet PCs, MSN Messenger automatically offers ink as an option for chatting. All MSN Messenger users with a new-enough (ver 5+, i think) version of the program can see the ink.
By the way, does anybody ever remember the 3d web browsers? They never seemed to get popular at all, and they were usually free!
Sorry about that, I didn't realise you were talking about the speed when the outside edge was being read. The way it was originally written made me think someone was stupid enough to think RPMs varied across the disk at any one particular instance in time.
The angular velocity, as measured sometimes by RPM, is CONSTANT over a rigid body. If your DVDs are experiencing different RPMs at the ourside edge than at the centre then i'd strongly suggest laying off the goofballs.
First Post!
Following his success in writing a book on Project Automation Dave Thomas decided he'd share his knowledge of Pragmatic Patty Production with the world.
In this tell all exposee of beefly manufacturing processes, he teaches the enthralled reader how to use common, freely available tools to automate build, test, and release highly beeftacular burgers at a fraction of the current cost!
Way to go, Dave Thomas!
"Linux is dead" - SCO
"SCO is dead" - Linux
"SCO is Linux" - the dead