In pure energy terms, heat pumps are approx 300% to 400% efficient (energy out to energy in ratio). Most electricity generated comes from coal / gas / oil with about a 50% efficiency conversion so overall heat pumps are around 150% to 200% efficient at turning coal / gas / oil into heat inside your home. Modern gas / oil boilers are about 80% efficient so heat pumps are the best overall method of heating a home. If you can get your electric from renewable sources then even better.
Ground source heat pumps get around 95% from solar heating (sun heating the ground) with only around 5% coming from geothermal.
This is the same as the gravity powered lamp (http://hardware.slashdot.org/article.pl?sid=08/02/20/1446256). It is a good idea that looks cool (cool enough to win awards) but has major drawbacks which make it completely impracticable to build.
Pylons typically have four large legs widely spaced apart for good reasons. Reducing them to two and making them very narrow isn't a good thing (TM). They also typically have 6 arms so as to keep the cost per cable down and each different design has to go through a lot of testing to ensure it can cope with the loads.
Nice blue sky thinking but an engineer hasn't been anywhere near the plans. If you want to give me an award, I to can come up with a nice pretty picture of a car that runs on one fried egg per 1000 miles. It's a nice sound bite but just as impossible to build.
El reg has made some interesting points on this: http://www.theregister.co.uk/2010/07/16/zephyr_7_days/ The site and time of year chosen is about the most ideal conditions possible. Any real application would require a payload which would need to be carried and more critically powered which means more solar panels. I would guess that they would already be maxed out on the solar panel area though...
"I have two children, one of whom is a boy born on a Tuesday. What's the probability that my other child is a boy?"
"I have two children, one of whom is a boy. What's the probability that my other child is a boy?"
Most people would think that the being born on a Tuesday bit was irrelevant and would make no difference to the answer. In fact it makes a big difference to the answer.
"In its first flight attempt, the Boeing [NYSE: BA] X-51A WaveRider today successfully completed the longest supersonic combustion ramjet-powered flight in history -- nearly three and a half minutes at a top speed of Mach 5."
My understanding is that it didn't reach the 300 seconds Mach 6 burn it was hoping for. 200 seconds and Mach 5 isn't all that bad though...
This is not a joke. It is insightful advise and it doesn't matter how many times you are told before you start, you will still learn this lesson the hard way.
There is a reason soldering iron handles are bright yellow. It will still not stop you from picking it up by the hot bit at least once...
Checks are old-fashioned, but what can replace them in the US? In the current banking system, giving out your account number for wire transfers isn't secure.
Why do you think giving out an account number is insecure? You do it every time you write a cheque. All companies here (the UK) give out their account details every time they invoice somebody as otherwise they won't get paid. Most utility bills come with a paying in slip which includes the utility companies bank account details. It really isn't a problem.
Everybody used to use cheques here (UK) but they are now almost completely replaced by plastic and bank transfers.
Why? Because people prefer carrying plastic than cheque books. Because people hate having to pay them in. Because cheques bounce. Because banks charge businesses to both write and receive cheques. Because there is a greater chance of fraud. Because it takes around three days for the money to arrive in your account and even then it is not guaranteed to have cleared.
Bank transfers are free, plastic costs the receiver a few %. Both are easy, simple, quick and fairly secure.
Why anybody would want to use a cheque, I really don't understand. Please explain.
One wheel failed years ago and a second failed recently. Both have shown signs of life recently but in the last attempt to move the Rover only 4 of the 6 wheels moved. The two wheels that failed are on the side with the best traction of course.
I can't pretend I understand it fully but it was something along the lines of multiple requests for images ending up looking like SYN flood or similar so the firewall blocked it. The speedtest is on a different IP so wouldn't be affected.
At the time, I was fully convinced it was something to do with my ISP but as I was at a good one (newnet) and nobody else was having issues, it had to be down to me. The strange thing was I had two different routers which did exactly the same thing. Switch off the firewall and all was fine.
Good luck with sorting this out. It was a very frustrating problem for me.
Try switching off the firewall in your modem. I had problems with sites with a lot of images and it turned out to be the modem firewall that caused the issue.
Be careful. The difference between MOST power supplies is the plug but there are some (mainly the older types) which will only work of the correct voltage supply.
Non grounded UK plugs are only allowed on items which are doubly insulated. This therefore requires two things to break before someone can be electrocuted.
If the lights dim when you switch on a 13A device then there is a problem with your wiring. Most likely because it is too thin. There are all sorts of regs here (in the UK) which dictate the losses allowed in the cables / cable thicknesses etc which if followed correctly mean that the lights should not dim as the voltage drop is minimal. Also note that here in the UK, a 13A device draw 3.1kW where as it is only 1.4kW in the US.
It is very rare for the sockets here to break and the pins on the plugs can't easily be bent unlike the US ones.
Also in the UK we use ring mains which allows the size of conductors to reduced by 30% or so which makes a considerably saving due to the price of copper.
"Leo Gross and his colleagues at IBM in Zurich, Switzerland, modified the AFM technique to make the most detailed image yet of pentacene, an organic molecule consisting of five benzene rings"
Apart from the fact that concrete attacks copper. All copper water pipes placed in concrete have to coated in plastic to protect them (at least in the uk).
I would use underfloor heating plastic pipes which are designed for this job. Sure they would need to be longer to get the heat transfer but the price would be similar and would be far less likely to leak. They certainly work fine in getting 6kW of heat into my house so absorbing a few hundred Watts would not be a problem.
Slashdot Mirror
In pure energy terms, heat pumps are approx 300% to 400% efficient (energy out to energy in ratio). Most electricity generated comes from coal / gas / oil with about a 50% efficiency conversion so overall heat pumps are around 150% to 200% efficient at turning coal / gas / oil into heat inside your home. Modern gas / oil boilers are about 80% efficient so heat pumps are the best overall method of heating a home. If you can get your electric from renewable sources then even better.
Ground source heat pumps get around 95% from solar heating (sun heating the ground) with only around 5% coming from geothermal.
If they do (which will break lots of things), the dongle will just use a valid id - this it trivial - and the merry-go-round will continue.
Does anybody know of a similar device that includes Homeplug so you can do away with the ethernet connection as well?
This is the same as the gravity powered lamp (http://hardware.slashdot.org/article.pl?sid=08/02/20/1446256). It is a good idea that looks cool (cool enough to win awards) but has major drawbacks which make it completely impracticable to build.
Pylons typically have four large legs widely spaced apart for good reasons. Reducing them to two and making them very narrow isn't a good thing (TM). They also typically have 6 arms so as to keep the cost per cable down and each different design has to go through a lot of testing to ensure it can cope with the loads.
Nice blue sky thinking but an engineer hasn't been anywhere near the plans. If you want to give me an award, I to can come up with a nice pretty picture of a car that runs on one fried egg per 1000 miles. It's a nice sound bite but just as impossible to build.
El reg has made some interesting points on this: http://www.theregister.co.uk/2010/07/16/zephyr_7_days/
The site and time of year chosen is about the most ideal conditions possible. Any real application would require a payload which would need to be carried and more critically powered which means more solar panels. I would guess that they would already be maxed out on the solar panel area though...
Compare these two questions:
"I have two children, one of whom is a boy born on a Tuesday. What's the probability that my other child is a boy?"
"I have two children, one of whom is a boy. What's the probability that my other child is a boy?"
Most people would think that the being born on a Tuesday bit was irrelevant and would make no difference to the answer. In fact it makes a big difference to the answer.
Maths fail..
No it isn't. Go and read the article again.
El Reg just thinks it is a complete PR exercise.
http://www.theregister.co.uk/2010/06/18/afghanistan_mineral_report/
Extracting the wealth is neither simple or sensible.
Boeing announcement here:
http://boeing.mediaroom.com/index.php?s=43&item=1227
"In its first flight attempt, the Boeing [NYSE: BA] X-51A WaveRider today successfully completed the longest supersonic combustion ramjet-powered flight in history -- nearly three and a half minutes at a top speed of Mach 5."
My understanding is that it didn't reach the 300 seconds Mach 6 burn it was hoping for. 200 seconds and Mach 5 isn't all that bad though...
More here:
http://www.theregister.co.uk/2010/05/27/x51_first_shot/
This is not a joke. It is insightful advise and it doesn't matter how many times you are told before you start, you will still learn this lesson the hard way.
There is a reason soldering iron handles are bright yellow. It will still not stop you from picking it up by the hot bit at least once...
Checks are old-fashioned, but what can replace them in the US? In the current banking system, giving out your account number for wire transfers isn't secure.
Why do you think giving out an account number is insecure? You do it every time you write a cheque. All companies here (the UK) give out their account details every time they invoice somebody as otherwise they won't get paid. Most utility bills come with a paying in slip which includes the utility companies bank account details. It really isn't a problem.
I really don't understand this.
Everybody used to use cheques here (UK) but they are now almost completely replaced by plastic and bank transfers.
Why? Because people prefer carrying plastic than cheque books. Because people hate having to pay them in. Because cheques bounce. Because banks charge businesses to both write and receive cheques. Because there is a greater chance of fraud. Because it takes around three days for the money to arrive in your account and even then it is not guaranteed to have cleared.
Bank transfers are free, plastic costs the receiver a few %. Both are easy, simple, quick and fairly secure.
Why anybody would want to use a cheque, I really don't understand. Please explain.
The shockwave is cone shaped rather than spherical for fast moving objects such as a rocket, I believe.
Very very cool though.
You need to read up on the IRA. Sometimes they did. Sometimes they did not.
The IRA are not nice people. (Neither are the UDA and other such terrorist organisations)
One wheel failed years ago and a second failed recently. Both have shown signs of life recently but in the last attempt to move the Rover only 4 of the 6 wheels moved. The two wheels that failed are on the side with the best traction of course.
plus 17.5% VAT (I doubt that they would be able to get one sent over before the new year).
£87 total http://www.google.co.uk/search?q=119%24+x+1.175+in+%C2%A3
Not bad. Might think about getting one.
I can't pretend I understand it fully but it was something along the lines of multiple requests for images ending up looking like SYN flood or similar so the firewall blocked it. The speedtest is on a different IP so wouldn't be affected.
At the time, I was fully convinced it was something to do with my ISP but as I was at a good one (newnet) and nobody else was having issues, it had to be down to me. The strange thing was I had two different routers which did exactly the same thing. Switch off the firewall and all was fine.
Good luck with sorting this out. It was a very frustrating problem for me.
If you have NAT running on your router then that will stop most nasties. Switch off the router firewall as a quick test just to prove me wrong.
My symptoms were identical to yours. Speed tests were fine but some sites with many images failed to load properly.
Try switching off the firewall in your modem. I had problems with sites with a lot of images and it turned out to be the modem firewall that caused the issue.
Alternatively, you could try giving your Veyron a salt water wash...
http://www.autoguide.com/auto-news/2009/11/video-bugatti-veyron-pulled-from-saltwater-lagoon-after-crash.html
Be careful. The difference between MOST power supplies is the plug but there are some (mainly the older types) which will only work of the correct voltage supply.
Always check the label before plugging it in.
Non grounded UK plugs are only allowed on items which are doubly insulated. This therefore requires two things to break before someone can be electrocuted.
If the lights dim when you switch on a 13A device then there is a problem with your wiring. Most likely because it is too thin. There are all sorts of regs here (in the UK) which dictate the losses allowed in the cables / cable thicknesses etc which if followed correctly mean that the lights should not dim as the voltage drop is minimal. Also note that here in the UK, a 13A device draw 3.1kW where as it is only 1.4kW in the US.
It is very rare for the sockets here to break and the pins on the plugs can't easily be bent unlike the US ones.
Also in the UK we use ring mains which allows the size of conductors to reduced by 30% or so which makes a considerably saving due to the price of copper.
"Leo Gross and his colleagues at IBM in Zurich, Switzerland, modified the AFM technique to make the most detailed image yet of pentacene, an organic molecule consisting of five benzene rings"
http://www.newscientist.com/article/dn17699-microscopes-zoom-in-on-molecules-at-last.html
Try This:
http://spacefellowship.com/Forum/forum-23.html
Apart from the fact that concrete attacks copper. All copper water pipes placed in concrete have to coated in plastic to protect them (at least in the uk).
I would use underfloor heating plastic pipes which are designed for this job. Sure they would need to be longer to get the heat transfer but the price would be similar and would be far less likely to leak. They certainly work fine in getting 6kW of heat into my house so absorbing a few hundred Watts would not be a problem.