I wouldn't be suprised. I just don't have a copy of the US rules, so I really can't say. The Canadian CFS (book listing airports) includes the phone numbers to towers and other ATC places for this purpose. Whenever I go flying, I bring my phone (turned off) just in case.
Nevertheless, tying up 20 cells is far more justified for emergency purposes than just for normal use, which is what a lot of people suggest. I know several flight instructors locally who bring their phone up for arbitrary conversation, which makes me shake my head.
People seem to be quite uninformed about this exact point every time it comes up on slashdot, and go on about conspiricies about airphones.
Using a little bit of logic, the cellphone network uses high frequency radio waves which propogate in a direct line-of-sight.
The cellphone system is set up so that frequencies can be reused. Generally, the cell that is using the same frequencies as yours is quite some distance away, and the curvature of the earth, etc., prevents any meaningful interference from it.
However, when you're in the air, you can jam the partiular frequency you've been assigned on several cells. Additionally, living anywhere near a border, you can also get some strange roaming fees.
This is why the FCC has banned the use of cells in planes, and why they are only allowed in Canadian airspace for emergency use only.
-legolas
(And, yeah... I would prefer a good ILS signal when landing with a 200ft ceiling. But, generally they make you turn off computers for landing phase of flight anyways)
I'd like to point out that the only virus/worm I've ever gotten (and I have several Windows machines) was that particularly nasty Apache worm that targetted FreeBSD machines. Yuck.
You're right... you are sounding like a broken record.:)
The story said "a ceremony referred to as Kipling", not "a pre/post iron ring ceremony social activity referred to as Kipling".
Anyways, Dalhousie is boring, and all we get is a post-iron ring exam crunch.:/ It doesn't help that somebody decided that 6 courses per term is a resonable work load.
While the provincial Professional Engineering acts do not restrict the use of "Engineering", Canadian copyright law does.
"CCPE maintains official marks on the terms engineer, engineering, professional engineer, P.Eng., consulting engineer, ingénieur, ing., ingénieur conseil, génie and ingénierie. This helps CCPE's constituent members to enforce the provisions of the Engineering Act in their jurisdiction, and protect the Canadian public through the regulation of engineering practice."
Context: I'm in my 4th year of Electrical and Computer Engineering at a Canadian university.
As I am getting towards the end of my degree and I'm getting ready to head out into the big world and work, we've started to be taught several ethics courses. Additionally, I have recently received my iron ring - a symbolic (and secret!) ceremony that affirms my commitment to public safety. Through this, I have been picking up the subtleties of a professional designation.
A Professional Engineer, like a Professional Doctor, Nurse, Lawyer, etc., has a deal of responsibility to the public at large. The privilege of being able to build large buildings, for example, comes at the cost of being responsible that the building doesn't fall. Accordingly, Professionals have professional bodies that they are accountable to above and beyond their responsibilities as a normal citizen. The laws are also much harsher on a professional when they don't act in a professional manner.
My main issue with software developers using the title "Engineer" is that the software development industry at large doesn't seem to adhere to the professional conduct demanded of a professional. Just take a look at the standard EULA as an example - imagine if the designers of bridges did a similar thing? While I have no qualms about the software developer "engineering" in the sense of creating, I wouldn't call a first aider a "doctor", despite the fact they do the same thing.
From my perspective, the ideal solution would be to integrate the software developing business into the Engineering profession. In addition to having a professional title, this would be a healthy step towards maturity of an industry that is plagued by antitrust, among other things. This could help bring respect and dignity to the software developer - in addition to more money - which I believe is what people really want.
Anyways, until such time as this happens, I'm not comfortable with the use of "Engineer" by software developers. In Canada, the term "Engineer" is actually copyrighted to the Canadian Council of Professional Engineers - a few years ago, there was actually a conflict with a University that provided an unaccredited course called "Software Engineering", claiming academic freedom. It resulted in a mess, including the temporary withdrawal of accreditation to the engineering programs at the university.
Well, you offered... so I guess I will correct you.:D
American-style nuclear reactors use a process called the Pressurized Water Reactor (PWR). This reactor uses pressurized water as the modulator and coolant. The water flows over the reactor core, heating up from the reaction in the fuel. The heat in this water is transfered (through a transfer chamber) to uncontaminated water, which boils and goes through a turbine. In fact, the non-nuclear side of the reactor (turbine hall, etc.) is not unlike that of a coal/oil/gas plant. One disadvantage of this setup, however, is that to keep the reaction going using standard water as the modulator, the uranium has to be enriched. (Which is expensive, and causes security concerns - as enriched uranium could be used for several other things).
CANDU technically stands for "Canada Deuterium Uranium". The CANDU reactor varies from its American counterpart by using non-enriched uranium. It makes up for the lack of reactivity by using deuterium ("Heavy Water") as its modulator and coolant. Being heavy, heavy water acts as a better modulator and can keep the reaction going with the lower grade of uranium.
There are really two disadvantages of the CANDU design over the PWR. First, PWR reactors can simply reach higher power levels than the CANDU. For example, the Bruce Nuclear Power facility runs 4 CANDU reactors. They have turbines rated to 1000MW, but can only output about 850MW. A PWR could go up to the full 1000MW. Additionally, heavy water has issues of its own. It is pretty expensive to create (although, through processes that occured in the 1970s, Canada is sitting on more heavy water than it knows what to do with.) On a day to day level, the iradiation of deterium produces a considerable amount of a 3rd isotope of water, tritium. Unlike light and heavy water, tritium is radioactive. As tritium is a beta emitter, contamination cannot be detected with the standard gamma portals at nuclear power sites - urine tests are a nessessity. Thankfully, processes exist to strip used heavy water of the tritium, so that it can be used again.
Now, the CANDU has several advantages as well. The first major one is the use of non-enriched fuel. This adverts much of the risk of dealing with weapons grade uranium fuel. Additionally, it helps keep the costs down.
Another neat aspect of the CANDU design is that it can be refuelled at full power. PWR reactors require at least a partial shutdown of a unit to refuel.
So, that's a basic overview of the CANDU design. A side note is that AECL (Atomic Energy of Canada Limited), the creators of the CANDU, are recently soliciting a new design, called the ACR-700 ("Advanced CANDU Reactor"). Unlike the previous design, it does use light water as the coolant. However, it retains the use of heavy water as the modulator.
Finally, to touch on two points in the above message (and my references will support this)...
The CANDU reactor is NOT a breader/fast reactor.
The CANDU reactor does NOT consume its own plutonium
It is simply a different type of reactor for electricity generation.
My point is that the hydrogen does have to be produced. "scrubed somehow" isn't really enough - to get the volumes nessecary for hydrogen cells, substances such as water generally have to be broken down. This requires a great deal of energy to do, which has to come from somewhere.
It is easy to see how nice the fuel cell is once it is created, but the actual creation of the cell has to be considered. As I stated earlier in the thread, if you have cars running on hydrogen cells and if you are burning coal/oil to create these hydrogen cells (and I would not assume the manufacturing process to be that efficient)... you really aren't further ahead. Worse, you could be even further back. For the fuel cells to really make a difference, there has to be a cleaner source of energy (nuclear/solar/wind/tidal/etc.) for the hydrogen capturing process.
However, the rate of efficiency is only as good as the efficiency of power used to generate the hydrogen in the first place. If you are using an oil/coal cycle with 20% to create a hydrogen cell with 99% efficiency, your hydrogen cell is only really 20% efficent.
And solar power is certainly not where efficiency can be found. While it would be nice if we could sustain our energy needs with solar/wind/etc., I'm afraid that at our currently increasing rate of consumption, it seems unlikely. (Without, at least, cutting down all the remaining forest for solar cells). When you move to a more northern climate, such as eastern Canada (where I live), the frequent fog, and generally low intensity of sunlight makes this go from unlikely to impossible.
Considering that 1 non-enriched uranium fuel pellet in a Candu reactor can produce more energy than several tons of coal... it seems like something worth looking into.
While everyone is quick to cheer on fuel cells as being über enviromentally friendly, as the process only produces water, etc. etc... people fail to remember that it takes a great deal of power to generate the hydrogen in these cells, and this power has to come from somewhere. Therefore, if we're running around with cars, laptops, etc., running these fuel cells and we are still relying on coal/oil power generation, then we are really no further ahead.
Nuclear is my vote for meeting the needs of the future, but i suppose your millage may vary.
I know this is slightly off topic, but it is something that should be kept in mind when discussing hydrogen fuel cells.
Slashdot Mirror
Iran already tried to address this by forging certificates for man-in-the-middle attacks.
I wouldn't be suprised. I just don't have a copy of the US rules, so I really can't say. The Canadian CFS (book listing airports) includes the phone numbers to towers and other ATC places for this purpose. Whenever I go flying, I bring my phone (turned off) just in case.
Nevertheless, tying up 20 cells is far more justified for emergency purposes than just for normal use, which is what a lot of people suggest. I know several flight instructors locally who bring their phone up for arbitrary conversation, which makes me shake my head.
-legolas
People seem to be quite uninformed about this exact point every time it comes up on slashdot, and go on about conspiricies about airphones.
Using a little bit of logic, the cellphone network uses high frequency radio waves which propogate in a direct line-of-sight.
The cellphone system is set up so that frequencies can be reused. Generally, the cell that is using the same frequencies as yours is quite some distance away, and the curvature of the earth, etc., prevents any meaningful interference from it.
However, when you're in the air, you can jam the partiular frequency you've been assigned on several cells. Additionally, living anywhere near a border, you can also get some strange roaming fees.
This is why the FCC has banned the use of cells in planes, and why they are only allowed in Canadian airspace for emergency use only.
-legolas
(And, yeah... I would prefer a good ILS signal when landing with a 200ft ceiling. But, generally they make you turn off computers for landing phase of flight anyways)
I'd like to point out that the only virus/worm I've ever gotten (and I have several Windows machines) was that particularly nasty Apache worm that targetted FreeBSD machines. Yuck.
-legolas
Hmmm... I remember Redhat shipping with a default running FTP server (wuftpd), with a widely accessable exploit.
But that's different...
"I installed Linux, and my computer was hacked twice within the first week." -- One of my university engineering mathematics profs.
-legolas
Maybe those |mathematical| types don|'|t know that i|t|'s spelled CURB|,| not KERB|.|
Local spelling differences aside, they seem to have a better grasp on basic grammar and proofreading.
-legolas
You're right... you are sounding like a broken record. :)
:/ It doesn't help that somebody decided that 6 courses per term is a resonable work load.
The story said "a ceremony referred to as Kipling", not "a pre/post iron ring ceremony social activity referred to as Kipling".
Anyways, Dalhousie is boring, and all we get is a post-iron ring exam crunch.
-legolas
I believe it's called the Iron Ring ceremony everywhere. Shorely someone is confused, as Rudyard Kipling was the author of the ceremony.
Also, this Computer and Software Engineering seems to be part of McMaster's engineering department, as opposed to a misnamed Computer Science degree.
-legolas
While the provincial Professional Engineering acts do not restrict the use of "Engineering", Canadian copyright law does.
"CCPE maintains official marks on the terms engineer, engineering, professional engineer, P.Eng., consulting engineer, ingénieur, ing., ingénieur conseil, génie and ingénierie. This helps CCPE's constituent members to enforce the provisions of the Engineering Act in their jurisdiction, and protect the Canadian public through the regulation of engineering practice."
(see here.)
In fact, the professional engineering body of Newfoundland pulled MUN's accreditation briefly over a "software engineering" program that they offered.
-legolas
Context: I'm in my 4th year of Electrical and Computer Engineering at a Canadian university.
As I am getting towards the end of my degree and I'm getting ready to head out into the big world and work, we've started to be taught several ethics courses. Additionally, I have recently received my iron ring - a symbolic (and secret!) ceremony that affirms my commitment to public safety. Through this, I have been picking up the subtleties of a professional designation.
A Professional Engineer, like a Professional Doctor, Nurse, Lawyer, etc., has a deal of responsibility to the public at large. The privilege of being able to build large buildings, for example, comes at the cost of being responsible that the building doesn't fall. Accordingly, Professionals have professional bodies that they are accountable to above and beyond their responsibilities as a normal citizen. The laws are also much harsher on a professional when they don't act in a professional manner.
My main issue with software developers using the title "Engineer" is that the software development industry at large doesn't seem to adhere to the professional conduct demanded of a professional. Just take a look at the standard EULA as an example - imagine if the designers of bridges did a similar thing? While I have no qualms about the software developer "engineering" in the sense of creating, I wouldn't call a first aider a "doctor", despite the fact they do the same thing.
From my perspective, the ideal solution would be to integrate the software developing business into the Engineering profession. In addition to having a professional title, this would be a healthy step towards maturity of an industry that is plagued by antitrust, among other things. This could help bring respect and dignity to the software developer - in addition to more money - which I believe is what people really want.
Anyways, until such time as this happens, I'm not comfortable with the use of "Engineer" by software developers. In Canada, the term "Engineer" is actually copyrighted to the Canadian Council of Professional Engineers - a few years ago, there was actually a conflict with a University that provided an unaccredited course called "Software Engineering", claiming academic freedom. It resulted in a mess, including the temporary withdrawal of accreditation to the engineering programs at the university.
Which was a bit counter-productive.
-legolas
As a licenced pilot, I am forced to hear this poem again and again, as Mr. Magee wrote this, allegedly, while flying.
As far as poems go, hearing this poem makes me consider taking up poetry as to write something to replace this.
In summation, nobody deserves this poem to be read to them, much less astronauts in an accident.
-legolas.
Thank-you.
-legolas
A solar setup is not much good when you don't get appreciable amounts of sun.
-legolas.
American-style nuclear reactors use a process called the Pressurized Water Reactor (PWR). This reactor uses pressurized water as the modulator and coolant. The water flows over the reactor core, heating up from the reaction in the fuel. The heat in this water is transfered (through a transfer chamber) to uncontaminated water, which boils and goes through a turbine. In fact, the non-nuclear side of the reactor (turbine hall, etc.) is not unlike that of a coal/oil/gas plant. One disadvantage of this setup, however, is that to keep the reaction going using standard water as the modulator, the uranium has to be enriched. (Which is expensive, and causes security concerns - as enriched uranium could be used for several other things).
CANDU technically stands for "Canada Deuterium Uranium". The CANDU reactor varies from its American counterpart by using non-enriched uranium. It makes up for the lack of reactivity by using deuterium ("Heavy Water") as its modulator and coolant. Being heavy, heavy water acts as a better modulator and can keep the reaction going with the lower grade of uranium.
There are really two disadvantages of the CANDU design over the PWR. First, PWR reactors can simply reach higher power levels than the CANDU. For example, the Bruce Nuclear Power facility runs 4 CANDU reactors. They have turbines rated to 1000MW, but can only output about 850MW. A PWR could go up to the full 1000MW. Additionally, heavy water has issues of its own. It is pretty expensive to create (although, through processes that occured in the 1970s, Canada is sitting on more heavy water than it knows what to do with.) On a day to day level, the iradiation of deterium produces a considerable amount of a 3rd isotope of water, tritium. Unlike light and heavy water, tritium is radioactive. As tritium is a beta emitter, contamination cannot be detected with the standard gamma portals at nuclear power sites - urine tests are a nessessity. Thankfully, processes exist to strip used heavy water of the tritium, so that it can be used again.
Now, the CANDU has several advantages as well. The first major one is the use of non-enriched fuel. This adverts much of the risk of dealing with weapons grade uranium fuel. Additionally, it helps keep the costs down.
Another neat aspect of the CANDU design is that it can be refuelled at full power. PWR reactors require at least a partial shutdown of a unit to refuel.
So, that's a basic overview of the CANDU design. A side note is that AECL (Atomic Energy of Canada Limited), the creators of the CANDU, are recently soliciting a new design, called the ACR-700 ("Advanced CANDU Reactor"). Unlike the previous design, it does use light water as the coolant. However, it retains the use of heavy water as the modulator.
Finally, to touch on two points in the above message (and my references will support this)...
The CANDU reactor is NOT a breader/fast reactor.
The CANDU reactor does NOT consume its own plutonium
It is simply a different type of reactor for electricity generation.
References:
Atomic Energy of Canada Limited - Creators of the CANDU reactor design. Corperate homepage.
British Energy - Fact File on Reactor Types
Atomic Energy of Canada Limited - Press release regarding commissioning of new CANDU reactor in China (August 13, 2002)
Bruce Nuclear Power Facility - Tiverton, Ontario.
-legolas.
My point is that the hydrogen does have to be produced. "scrubed somehow" isn't really enough - to get the volumes nessecary for hydrogen cells, substances such as water generally have to be broken down. This requires a great deal of energy to do, which has to come from somewhere.
It is easy to see how nice the fuel cell is once it is created, but the actual creation of the cell has to be considered. As I stated earlier in the thread, if you have cars running on hydrogen cells and if you are burning coal/oil to create these hydrogen cells (and I would not assume the manufacturing process to be that efficient)... you really aren't further ahead. Worse, you could be even further back. For the fuel cells to really make a difference, there has to be a cleaner source of energy (nuclear/solar/wind/tidal/etc.) for the hydrogen capturing process.
-legolas.
However, the rate of efficiency is only as good as the efficiency of power used to generate the hydrogen in the first place. If you are using an oil/coal cycle with 20% to create a hydrogen cell with 99% efficiency, your hydrogen cell is only really 20% efficent.
And solar power is certainly not where efficiency can be found. While it would be nice if we could sustain our energy needs with solar/wind/etc., I'm afraid that at our currently increasing rate of consumption, it seems unlikely. (Without, at least, cutting down all the remaining forest for solar cells). When you move to a more northern climate, such as eastern Canada (where I live), the frequent fog, and generally low intensity of sunlight makes this go from unlikely to impossible.
Considering that 1 non-enriched uranium fuel pellet in a Candu reactor can produce more energy than several tons of coal... it seems like something worth looking into.
-legolas.
While everyone is quick to cheer on fuel cells as being über enviromentally friendly, as the process only produces water, etc. etc... people fail to remember that it takes a great deal of power to generate the hydrogen in these cells, and this power has to come from somewhere. Therefore, if we're running around with cars, laptops, etc., running these fuel cells and we are still relying on coal/oil power generation, then we are really no further ahead.
Nuclear is my vote for meeting the needs of the future, but i suppose your millage may vary.
I know this is slightly off topic, but it is something that should be kept in mind when discussing hydrogen fuel cells.
-legolas.