Why is recycling the batteries Nissan's problem? Recycling the lead-acid accumulator in a ICE car or the used engine oil isn't Ford's (etc.) problem or expese? Nissan doesn't own the batteries in sold cars.
It probably can, but I think the point is that these used batteries are cheaper than new/recycled batteries, and still provide a quite good power density for a stationary application (just not good enough for a car).
So this way, it is possible to get a few more years out of a battery pack before it needs to be recycled.
Ah, thanks! It seems to be similar to SPOT then (both using Globalstar and both being "send only" devices). Interesting that the battery lifetime is so completely different - this device advertised to last for 7 years on a single battery with 2 messages / day!
Unfortunately, anything Globalstar seems to be less-than-perfect for aircraft tracking, as their constelation doesn't cover large parts of the world: http://www.globalstar.com/en/i...
Interesting - do you have a link to the device, or the name of the system?
I know of emergency radiobeacons (which are basically one-way/send-only devices, only activating when triggered) which do have such battery life, and SPOT GPS trackers (which only last for ~2 weeks when in tracking mode / 1 yr standby, and are also one-way devices) - but something that passively listens for satellite comms signals for ~5 years (i.e. operating a satellite radio reciever) for a trigger and is the size of a small cellphone, I've never heard of.
Or simply something similar to what is implemented in laptops and cellphones, which charge & run from the external circuit, and automatically switch to battery power if external power is lost.
There may still be a legitimate need to switch of power. OTOH, if the chance of fire is *really* low, and the energy stored in the battery is too small to be dangerous, it may still be OK to just switch off external power.
You may want to be able to cut power to the device, not just "switch off" as send an electrical signal which basically means "please switch yourself off".
Further, it is actually possible to disable the CVR and FDR ("the black box") - just trip the circuit breaker. There may be some battery backup, but this only lasts for ~10 minutes: http://books.google.fr/books?i... This happened on SilkAir flight 185, which probably was deliberately crashed by its captain: http://en.wikipedia.org/wiki/S...
Whether the transmitters which may or may not have been running on this flight where possible to switch off, I don't know - one possible location is actually inside the engine nacelle - so it may have been wired to be always on as long as the engine is running, shutting down when the engine control circuitry looses power. Or maybe the pilot just didn't know about them?
That both things have been done does not mean they're equally easy / expensive. Flying to the moon is harder than walking to the store across the street - both are possible, both have been done, but the effort needed is not the same. In this case cellular modems are much simpler / cheaper than satellite modems, and the data charges are orders of magnitude different. And even then, satellite coverage isn't perfect everywhere. For some examples, take a look at the wikipage for mobile satellite internet: http://en.wikipedia.org/wiki/S... Prices are in the ~5$/MB range, 9.6-60 kb/s bandwidth. There are other "non mobile" and cheaper solutions (which I believe are used for in-flight WiFi) which also provide better bandwidth, but they require a dish which tracks a geostationary satellite. It usually looks like a "hump" on the top of the plane, roughly above the from door of a 737 (at least this is how Norwegian Air Shuttle mounts them) - and I wouldn't want to rely on such a complicated system for emergency comms.
Also, as far as I understand, most modern aircraft does NOT have satellite *tracking*, but some have ACARS installed, which basically sends automatic status messages back to the airlines maintenance crews (sometimes containing position fixes), and may also be used as a "email" system between the airline, plane, and air traffic control. The missing Malaysia airlines plane (after what I understand) DID have ACARS, but only the HF radio version of it, not satellite.
Maybe if there was some insurance trickery going on? Say someone on the plane took out a huge life insurance and then hijacked the plane - there won't be any payout if it's a suicide. However if the plane is never found, then no-one can prove it was a suicide or foul play...
Yup, micro-usb 3 is mechanically horrible. I have a portable external HDD where the ground part of the connector ripped right of the circuit board. So now I have to use a screwdriver to dissasemble the thing and reseat the little metal piece every time I want to use the HDD... I should probably use a soldering iron to fix it "permanently"...
Sure, power flow is important to whether a glow discharge turns into an full-blown breakdown / arc or not - but in this case, the time constants of the plasma are much much smaller than the AC's 1/f anyway - the plasma will extinguish when the field has a zero-crossing.
But yes, in this case, power line frequencies are pretty much DC, as the plasma is formed around high electric field regions, and the time for the plasma to form and stabilize is much quicker than 1/100 sec anyway.
The only thing that may make it slightly different from DC, is that you may only get a plasma for half the wave, and may not have the initial ionization event every time the field is in the plasma-forming direction. That could result in an "interupted"/flashing plasma, while a DC line would tend to maintain a steady discharge once the plasma is formed.
Anyway, I don't really see how safe to touch voltages are relevant - it's not the corona discharge that kills you, and coronas doesn't have nerves so I don't think they care about either Westinghouse, Tesla, or Eddison:)
I come from a relatively small country population-vise, but not so small distance-vise - it's about 1700 km end-to-end on a great circle, although the part which is built out with a network of electrified rail is only about 700 km end-to-end. So the electrified train network spans (as in the shortest distance between the two furthest apart points) the about the same distance as Texas, measured east-west. Not all of this is heavily trafficked (although most places see much traffic than one train/day, both goods and people - when you build the infrastructure, it tends to get used), and it's a quite mountainous landscape so it's much harder to build tracks than on open plains with dessert climate. This network is of course linked to similar networks in neighboring countries (which again link up with the rest of the eurasian rail network), so quite a bit of goods get moved this way, also long distances. Trade unions and agreements for free movement of people is in place, so crossing the border is about as much hassle as crossing a state border in the US.
And no, I don't mean a third rail - this is what you generally use for subways, not trains where the standard is to lift the electric lines above ground, connecting to it with a pantograph http://en.wikipedia.org/wiki/P...
Further, you'll find tons of non-electric trains in very urban settings in the US - take the Caltrain for example, which is serving the Bay Area in CA - no electrification, level crossings in the middle of residential areas, and painfully slow - in a densely populated and quite wealthy area, where road transport is already at or above capacity during rush hours and no good alternatives for building more hi-capacity roads. Why is it so? Why not modernize at least these lines?
Anyway, the main point is that to avoid "burning tons of diesel to power the trains", one way to solve that is to power the trains electrically, which also has the bonus of making it easier to move other types of goods.
Not just domestic, but inside Schengen. I've flown to Switzerland (once, and I've flown that route MANY times) without showing any ID ever - checkin was automatic, bagdrop was automatic, and from then on I just had to show the bording card (which no-one actually looked at except to beep the barcode). I could have checked in in your name without any issues.
Basically the airlines are the only ones checking any ID as long as you're flying inside Schengen.
Similar in Norway - university is basically free (except the 100 USD/year mandatory student union member ship), and you get a subsidised (i.e. no interest before you graduate, (much) lower-than-market interest rate after that) loan for up to ~7 years. This loan works so that when you pass your exams for that semester, ~half of the loan is turned into a stipend. Don't pass your exams and you have to pay it back.
On top of this, you have access to subsidised housing in "student villages" - these are apartments where you get your own room, and share a kitchen/bathroom with ~4-10 people - accomodation standards depend on how much you want to pay, but it is in general affordable within the budget of student loans. You can use the apartment year round, i.e. if you have a summer job in the city or you are a last-year masters student working at the university over the summer, no-one will kick you out. It's like a normal apartment, just cheaper, and everyone else in the same block are also students. There are also possible to get two-person apartments, i.e. for people who want to move in with their S.O. - with no strings attached about marriage etc.
And on top of that, you do of as a citizen get access to healthcare (hospitals are free to use, normal doctors appointments and medicine are cheap up to a certain limit after which is it free, the dentist you pay out of pocket but it's usually not that expensive and there are often student discounts available) and disability insurance.
I never hear of any vehicle where the breaks are actually fly-by-wire, neither the steering. Neither any manual transmission wich is fly-by-wire. Throtle and engine control yes, but I don't know if it's usually on the same bus as everything else, or on a separate network.
Extracting and refining oil isn't exactly "green" either - especially now that we're used a lot of the conventional sources, and tar sand etc. is getting profitable.
The strangest part is that they make a huge que (actually two - 1st passport check (slooooow), then a new security check (reasonably quick) ) for people who are not even going TO the UK, but continuing onwards to other places (like USA).
I've never been inside the UK, but I did go to Ireland once (which is also non-Schengen). After handing back our passports, the passport check guy told us (in a very irish accent) to "don't burn down our churches, we remember what happened last time you where here!", and looked at us very seriously for a few secounds before holding up a finger on each side of his head, making "viking horns". It took us a while before we understood it was a joke - it was so far off what we expected!
Even if the brakes would have stopped the car (eventually), after applying them fairly firmly for a while (for some values of "while") the car can experience rather sever brake fade. Anyone driving in the mountains has probably experienced this.
I always learned (and do) break on the transmission when going down long steep hills - I normally don't have to touch the break pedal at all. On a manual this is obvious how to do (just downshift untill appropriate speed is reached, and don't redline the engine, use the breaks to CHANGE speed, not to keep from running away). On automatics there is (in my tiny experience of these) usually a possibility to force it to a specific gear, basically driving it as a clutchless manual, or at least a "low gear" button/position on the transmission handle.
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Why is recycling the batteries Nissan's problem? Recycling the lead-acid accumulator in a ICE car or the used engine oil isn't Ford's (etc.) problem or expese? Nissan doesn't own the batteries in sold cars.
It probably can, but I think the point is that these used batteries are cheaper than new/recycled batteries, and still provide a quite good power density for a stationary application (just not good enough for a car).
So this way, it is possible to get a few more years out of a battery pack before it needs to be recycled.
Ah, thanks! It seems to be similar to SPOT then (both using Globalstar and both being "send only" devices). Interesting that the battery lifetime is so completely different - this device advertised to last for 7 years on a single battery with 2 messages / day!
Unfortunately, anything Globalstar seems to be less-than-perfect for aircraft tracking, as their constelation doesn't cover large parts of the world:
http://www.globalstar.com/en/i...
Interesting - do you have a link to the device, or the name of the system?
I know of emergency radiobeacons (which are basically one-way/send-only devices, only activating when triggered) which do have such battery life, and SPOT GPS trackers (which only last for ~2 weeks when in tracking mode / 1 yr standby, and are also one-way devices) - but something that passively listens for satellite comms signals for ~5 years (i.e. operating a satellite radio reciever) for a trigger and is the size of a small cellphone, I've never heard of.
Or simply something similar to what is implemented in laptops and cellphones, which charge & run from the external circuit, and automatically switch to battery power if external power is lost.
There may still be a legitimate need to switch of power. OTOH, if the chance of fire is *really* low, and the energy stored in the battery is too small to be dangerous, it may still be OK to just switch off external power.
You may want to be able to cut power to the device, not just "switch off" as send an electrical signal which basically means "please switch yourself off".
Further, it is actually possible to disable the CVR and FDR ("the black box") - just trip the circuit breaker. There may be some battery backup, but this only lasts for ~10 minutes:
http://books.google.fr/books?i...
This happened on SilkAir flight 185, which probably was deliberately crashed by its captain:
http://en.wikipedia.org/wiki/S...
Whether the transmitters which may or may not have been running on this flight where possible to switch off, I don't know - one possible location is actually inside the engine nacelle - so it may have been wired to be always on as long as the engine is running, shutting down when the engine control circuitry looses power. Or maybe the pilot just didn't know about them?
Oh, and you may actually *want* the pilot to be able to disable such systems. As an example, what if it catches on fire?
That both things have been done does not mean they're equally easy / expensive. Flying to the moon is harder than walking to the store across the street - both are possible, both have been done, but the effort needed is not the same. In this case cellular modems are much simpler / cheaper than satellite modems, and the data charges are orders of magnitude different. And even then, satellite coverage isn't perfect everywhere. For some examples, take a look at the wikipage for mobile satellite internet:
http://en.wikipedia.org/wiki/S...
Prices are in the ~5$/MB range, 9.6-60 kb/s bandwidth. There are other "non mobile" and cheaper solutions (which I believe are used for in-flight WiFi) which also provide better bandwidth, but they require a dish which tracks a geostationary satellite. It usually looks like a "hump" on the top of the plane, roughly above the from door of a 737 (at least this is how Norwegian Air Shuttle mounts them) - and I wouldn't want to rely on such a complicated system for emergency comms.
Also, as far as I understand, most modern aircraft does NOT have satellite *tracking*, but some have ACARS installed, which basically sends automatic status messages back to the airlines maintenance crews (sometimes containing position fixes), and may also be used as a "email" system between the airline, plane, and air traffic control. The missing Malaysia airlines plane (after what I understand) DID have ACARS, but only the HF radio version of it, not satellite.
Communication is much easier for a car - you can use the cellular network. Not so much for a plane, where you need to use satellite comms.
Maybe if there was some insurance trickery going on? Say someone on the plane took out a huge life insurance and then hijacked the plane - there won't be any payout if it's a suicide. However if the plane is never found, then no-one can prove it was a suicide or foul play...
Yup, micro-usb 3 is mechanically horrible. I have a portable external HDD where the ground part of the connector ripped right of the circuit board. So now I have to use a screwdriver to dissasemble the thing and reseat the little metal piece every time I want to use the HDD... I should probably use a soldering iron to fix it "permanently"...
Sure, power flow is important to whether a glow discharge turns into an full-blown breakdown / arc or not - but in this case, the time constants of the plasma are much much smaller than the AC's 1/f anyway - the plasma will extinguish when the field has a zero-crossing.
Yes, RF guy indeed :)
But yes, in this case, power line frequencies are pretty much DC, as the plasma is formed around high electric field regions, and the time for the plasma to form and stabilize is much quicker than 1/100 sec anyway.
The only thing that may make it slightly different from DC, is that you may only get a plasma for half the wave, and may not have the initial ionization event every time the field is in the plasma-forming direction. That could result in an "interupted"/flashing plasma, while a DC line would tend to maintain a steady discharge once the plasma is formed.
Anyway, I don't really see how safe to touch voltages are relevant - it's not the corona discharge that kills you, and coronas doesn't have nerves so I don't think they care about either Westinghouse, Tesla, or Eddison :)
I would think so - corona discharges are dependent on electric field, not frequency (and 50/60 Hz is pretty much DC anyway).
I come from a relatively small country population-vise, but not so small distance-vise - it's about 1700 km end-to-end on a great circle, although the part which is built out with a network of electrified rail is only about 700 km end-to-end. So the electrified train network spans (as in the shortest distance between the two furthest apart points) the about the same distance as Texas, measured east-west. Not all of this is heavily trafficked (although most places see much traffic than one train/day, both goods and people - when you build the infrastructure, it tends to get used), and it's a quite mountainous landscape so it's much harder to build tracks than on open plains with dessert climate. This network is of course linked to similar networks in neighboring countries (which again link up with the rest of the eurasian rail network), so quite a bit of goods get moved this way, also long distances. Trade unions and agreements for free movement of people is in place, so crossing the border is about as much hassle as crossing a state border in the US.
And no, I don't mean a third rail - this is what you generally use for subways, not trains where the standard is to lift the electric lines above ground, connecting to it with a pantograph http://en.wikipedia.org/wiki/P...
Further, you'll find tons of non-electric trains in very urban settings in the US - take the Caltrain for example, which is serving the Bay Area in CA - no electrification, level crossings in the middle of residential areas, and painfully slow - in a densely populated and quite wealthy area, where road transport is already at or above capacity during rush hours and no good alternatives for building more hi-capacity roads. Why is it so? Why not modernize at least these lines?
Anyway, the main point is that to avoid "burning tons of diesel to power the trains", one way to solve that is to power the trains electrically, which also has the bonus of making it easier to move other types of goods.
Why not electrify the main rail routes, like most non 3rd world country did 50 years ago? That would also not only benefit the oil trains.
Not just domestic, but inside Schengen. I've flown to Switzerland (once, and I've flown that route MANY times) without showing any ID ever - checkin was automatic, bagdrop was automatic, and from then on I just had to show the bording card (which no-one actually looked at except to beep the barcode). I could have checked in in your name without any issues.
Basically the airlines are the only ones checking any ID as long as you're flying inside Schengen.
Once uppon a time, I enjoyed VB6. Then it went away, and I learned not to thrust a single vendor for providing me with a compiler...
Similar in Norway - university is basically free (except the 100 USD/year mandatory student union member ship), and you get a subsidised (i.e. no interest before you graduate, (much) lower-than-market interest rate after that) loan for up to ~7 years. This loan works so that when you pass your exams for that semester, ~half of the loan is turned into a stipend. Don't pass your exams and you have to pay it back.
On top of this, you have access to subsidised housing in "student villages" - these are apartments where you get your own room, and share a kitchen/bathroom with ~4-10 people - accomodation standards depend on how much you want to pay, but it is in general affordable within the budget of student loans. You can use the apartment year round, i.e. if you have a summer job in the city or you are a last-year masters student working at the university over the summer, no-one will kick you out. It's like a normal apartment, just cheaper, and everyone else in the same block are also students. There are also possible to get two-person apartments, i.e. for people who want to move in with their S.O. - with no strings attached about marriage etc.
And on top of that, you do of as a citizen get access to healthcare (hospitals are free to use, normal doctors appointments and medicine are cheap up to a certain limit after which is it free, the dentist you pay out of pocket but it's usually not that expensive and there are often student discounts available) and disability insurance.
I like our system :)
I never hear of any vehicle where the breaks are actually fly-by-wire, neither the steering. Neither any manual transmission wich is fly-by-wire. Throtle and engine control yes, but I don't know if it's usually on the same bus as everything else, or on a separate network.
Why does the motor need to be replaced?
Extracting and refining oil isn't exactly "green" either - especially now that we're used a lot of the conventional sources, and tar sand etc. is getting profitable.
The strangest part is that they make a huge que (actually two - 1st passport check (slooooow), then a new security check (reasonably quick) ) for people who are not even going TO the UK, but continuing onwards to other places (like USA).
I've never been inside the UK, but I did go to Ireland once (which is also non-Schengen). After handing back our passports, the passport check guy told us (in a very irish accent) to "don't burn down our churches, we remember what happened last time you where here!", and looked at us very seriously for a few secounds before holding up a finger on each side of his head, making "viking horns". It took us a while before we understood it was a joke - it was so far off what we expected!
As one engineer explained: at 6 km altitude, if a computer reboots for 20 seconds, not much happens, and time is left to regain control afterwards
Not true during landing/takeoff at least.
Even if the brakes would have stopped the car (eventually), after applying them fairly firmly for a while (for some values of "while") the car can experience rather sever brake fade. Anyone driving in the mountains has probably experienced this.
I always learned (and do) break on the transmission when going down long steep hills - I normally don't have to touch the break pedal at all. On a manual this is obvious how to do (just downshift untill appropriate speed is reached, and don't redline the engine, use the breaks to CHANGE speed, not to keep from running away). On automatics there is (in my tiny experience of these) usually a possibility to force it to a specific gear, basically driving it as a clutchless manual, or at least a "low gear" button/position on the transmission handle.