About 20 years ago at work we estimated the build cost of a piece of complicated equipment using a program called PRICE (I believed developed by RCA). Two of the key determining factors of cost were size and weight. We thought no way are weight and size that important. Over the years I have decided this not to be true. For similar items as weight goes down so does cost. Yes making stuff light weight means it is less rugged but cheaper. Think of hard drives. My first one was a 10 meg that weighed 5-10 lbs and took up the space that two 5-1/4" CD drives do today. These disks failed quite often and cost several hundred $ in the 1980s. Just bought a 120G byte drive on special for $49. Maybe it weighs 1/10 of the old drive.
A few years ago I went to a talk on making a position sensor for fire fighters. Remember GPS works poorly inside buildings. The idea was to use microaccelorometers to track the position of the firefighter inside a building. The author mentioned they placed the device in the heel of the boot. This way they could sense when the motion was stopped so they could rezero the accelerometers. Eliminating zero drift has always been a problem with guidance systems.
Methane from the DC sewage plant was used to heat the Naval Research Lab where I worked for years. One problem is the methane has quite a bit of air and CO2 in it so the facility where it is burned must be able to adjust the air to fuel ratio dynamically. We were next door to sewage plant so connecting to the methane source was no big deal. Of course when the wind came from the south we certainly knew who our next door neighbor was.
At what point is enough people enough? If we don't so something mother nature surely will. Actually we should have done a lot in the 1970's to reduce population growth, now I don't see anything but catastrophe in our future. Reducing consumption by 50% and doubling your population buys you nothing. Due to the lifetime of humans it is better late than never at seriously curbing population growth. Go to the CIA world fact book and look at children per woman for various countries. For example Iraq it is 4.18 and the population is young so even if the birth rate drops to about 2, there still will be a large increase in population. This means lots of young men have no hope or jobs and are attracted to the dark side. Another factoid: I remember reading a few years ago that if women in India only had two children from now on the population would level off at about two billion towards the end of this century. Is it possible for India to support twice its population, especially with end of cheap energy which equals cheap fertilizer and transporation? I don't think so. Maybe some of you can offer some hope but I don't see much.
The USMC developed the Dragon Eye and has been using it in IRAQ. See for example http://www.defense-update.com/products/d/dragoneye s.htm Note for simplicity there are no control surfaces. Control is performed by adjusting the power of the two electric motors. I have seen it fly and it is very quiet, which is the key for not being detected. Often at demos the sponsors were shown a TV screen showing themselves looking at the TV and then they would look up for it. The most useful TV camera is placed looking down and sideways and the GPS controller is programmed to have the Dragon Eye circle the target co-ordinates. This way the camera is always looking at the target of interest from different directions. It can fly a preprogammed pattern or be redirected by the person in charge. It also qualifies as a "model airplace" so you don't have to get the FAA involved in approving your flight plan.
Ok so HP went too far, not sure if law was broken, but George Keyworth's blabbing to a reporter started this. Considering that members of a board of directors often get paid big bucks for attending a few meetings, plus first-class expenses, they owe a fiduciary responsibility to the share holders they are working for and not divulging company information to a reporter. Often boards just go along with the CEO for fear of being kicked off the board and loosing the big bucks they get for little time or work. If you don't believe me check out the annual proxy statements for HP, in 2004 each member of the board received a $200k retainer. Not too bad.
Go to the Eveready web site
on
USB Batteries
·
· Score: 1
The Eveready site, http://data.energizer.com/ shows that NiMH AA batteries have 30-40 milliohms internal resistence and can be used to put out 4A continuously. For the Li AA they don't recommend more than 3A burst mode, so in fact the NiMH batteries should be just as suitable. I always do carry some Li batteries as emergency spares, for one thing they have essentially unlimited life (90% power after 15 years!). NiMH batteries lose 1-2% of their charge per day so you need to charge every month to make sure they aren't too low on charge.
I believe it was the willingness of Hezbolah fighters to fight to the death that the difference. In the past other fighters would break and run under superior fire power. Now they hole up and take casualities. I would bet they learned tactics from Iraq. Well dug in infantry that is willing to fight will always cause a lot of casualities. Even if a someone in Hezbolah intercepted some messages, they would have to then communicate their response to many groups of fighters widely scattered. I doubt the control and communication was that good. Particulary when any movement of significant numbers would result in a punishing air strike.
Sometimes we make a straight forward problem hard. We can dig deep mines in geologically stable places. For example check out: http://en.wikipedia.org/wiki/Soudan_Mine (worth a tour). I think there is a whole industry of folks who get money from DOE to over research this problem. As a former researcher the ideal for you is to keep the funding stream going, never solve the problem just keep getting $$ for further studies. My only concern about burial would be a meteor strike ejecting the material into the atmosphere which could be catastophic.
Biggest money sink for folks your age is a car. Don't buy a new car. Find a used one. Certain brands don't have great resale value so take advantage of it, for example Chevy Malibu. Maybe a relative is trading in a car and will give you a good deal. Sure it may not be new or sexy, but the savings in depreciation, insurance, etc will be significant.
Don't forgo good experiences. Do some traveling in foreign countries, maybe spend the summer volunteering somewhere interesting. Sure these cost $$, but you will have the memories the rest of your life. This is in contrast to young adults who go to party places like Cancun over spring break. It's a lot cheaper to get drunk at college.
The shuttle has 3 auxillary power units. One is necessary to land. They are routinely tested while in space. If one fails they land as soon as possible. The APUs are not small, they are powered by a 100 horsepower turbine which is turned by decomposing hydrazine over a catalyst. Sometimes on good movies of the shuttle after it has landed you can see the heat waves from the hot gases (nitrogen, hydrogen, and a little ammonia) from the decomposing hydrazine coming straight up from the shuttle.
The larger thrusters and the rocket engine used by the shuttle in space are powered by methyl hydrazine reacting with nitrogen dioxide. These are hypergolic (burn on contact with each other) so no possiblity of them failing to ignite for a second or two then going boom which is possible with other fuels like hydrogen and oxygen. They are liquids at ambient temperatures so don't require cryogenic storage.
Hydrazine, N2H4, is a great rocket fuel. It is a liquid with similar boiling and freezing points to water -- but can explosively decompose (it is dangerous to measure its boiling point), is toxic at ppm levels, is carcinogenic (ie all the rats that breathed it got nasal cancer), causes skin burns. Like most amines it smells like rotten fish. Believe it or not there are people who believe that low levels in the blood is an anti cancer agent.
I think many users would want a system that would work from most any computer. For example, home, work, parents' house, etc. Couldn't the bank check the path of the packets it receives for suspect routing paths or maybe even unusual delays? It also could require you to confirm by email any unusual request.
I have worked with these lubricants. They have high vapor pressures and migrate all over all surfaces inside the volume where they are sealed. Probably good idea to have something equivalent to a saturated sponge inside the disk drive. Don't see the need for nanotubes. I would worry more about the motor bearings failing.
Other than Korea where large mine fields exist, US mines are designed to be applied remotely. These mines land on the surface and can have wires than are ejected after landing. Depending upon which wire is disturbed the mine will explode in the direction of that particular wire. The mines are designed to be put in front of an enemy to stop rapid movement, particularly at night time. They have self deactivating timers so do not pose a long term problem. In general this is well advanced technology and resources should not be applied to improving it when there are so many other pressing needs. Obviously this has no relevance in the war on terror unless you want to start mining Afghanistan (oops, USSR tried that and it didn't win their war).
Look we have had 120 flights, next one is STS-121. Challenger problem has been fixed so it doesn't count. So based on past performance one can say odds are about 1 in 100 something fatal may happen. I believe we only have about 20 more shuttle launches planned so odds are quite good nothing awful will happen. Maintaining the infrastructure is quite expensive so it's time to get on with it. We have three shuttles so there should be no problem finishing the station which is the only reason for maintaining the shuttle. I don't want to get into discussing the station as I start foaming at the mouth about what a waste of resources. Of course using a shuttle mission for something valuable to humankind, like prolonging the life of the space telescope is out of the question. I think NASA's motto has become "To unboldly not to go".
The real problem is that both Los Alamos and Lawrence Labs purpose was to design nuclear weapons which we know longer need to do. They are always searching for the need for a new weapon. A few years ago and still today they are pushing for a bunking busting nuke. Great way to generate lots of nuclear fallout from detonating the bomb in the ground. Right now they are looking to build a newer, higher reliability bomb. I am sure most of the scientists who would work on these projects know it is a great waste of resources. Yes, we need to keep a core expertese on nuclear weapons, but let's switch the major effort at these labs to deal with lack of cheap energy and so to be energy at any price.
Have the machine beep when an access cover is opened to a port to enable reprogramming. Opening the cover would require breaking tamper resistent tape and require a new code word to reprogram. The code word would be written to a write-once chip. The new code word must be different from prior ones. Code words would change daily and be available over the internet. The machine's Bios would require unsoldering a chip to change, on boot up it would display the last few code words for 10 seconds before beginning the reprogrammable code.
In the story the credit card company said the funds were held up due to security reasons. Thus I assume the credit card company was collecting interest during this time. Which means it is to their advantage to do this. It seems to me that credit card companies do all they can to nickel and dime you (more like 39.95 you) for example paying a day late. This annoys me since they get to charge you interest and would prefer you to be late.
In so far as overboard security procedures it is an example of a win for Bin Laden. Probably does little for real security but bleeds our resources. Which by the way was in a recent statement as a goal of Al Queda
This is not new information about brain development. About 15 years ago, I attended a lecture about gifted students who under performed. The lecturer commented that often for males the ability to perform executive tasks did not fully develop until age 25. Executive skills are defined as being able to take a large task and break it in to smaller tasks that are manageable in order to accomplish the task. In contrast the ability to play a simple video game that requires rapid hand-eye coordination was fully developed by age 6.
But we have a selective breeding program to breed brighter humans. Our children are tested and the brightest ones and ones with sucessful parents (have $$) are placed together at time in their lives with a high probability of selecting a mate. Worked for me when I was in college.
I recall reading a story about the development of the IPOD. Several times Jobs looked at the prototype and said, "Change it, I don't like this feature." Because he controlled Apple this could happen even if it caused the schedule to slip and cost $$$. When you are right this is great. On the other hand Henry Ford stuck with the Model T too long, because he misread the consumer's needs.
Jobs certainly has the ability to judge what will make something become a unique product. Wonder if he will have the same skills at picking movies for Disney to produce.
For televisions with CRTs the filament is partially powered during standby. This allows faster warmup and increases the lifetime of the picture tube. Why, the thermal cycling of the electron gun cathode from ambient to red hot causes failure due to thermal stresses. It is better to keep the thermal stresses down by keeping the filament partially energized. Yes this consumes a few watts but from a consumer's point of view, this is a cost saver since failure of the picture tube will result in replacement of the entire TV set. Ditto for CRT monitors.
Interestingly when I was in Mexico this summer I observed that most incandescent bulbs had been replaced by compact fluorescents.
Finally one of the first actions of the Bush administration was to reduce the required efficiency standard for new home air conditioners. Doubly bad increases energy use and particularly peak energy use.
In terms of energy policy as the old Hank Snow song says:
"Warning signs are flying by us but we pay no heed,
Instead of slowing down the pace we keep pickin' up the speed.
Disaster's getting closer every time we meet.
Doin' 90 miles an hour down a dead end street."
Most vehicles in space use a combination of thrusters and reaction wheels. Essentually a flywheel on each axis is spun up or down to rotate the vehicle. Eventually the wheel is moving too fast and a thruster is used to spin the vehicle so that the wheel can be slowed down. For moving the vehicle it is important to have the thrust vector point at the CG of the vehicle, else a torque is produced causing spinning which requires an additional thruster to compensate.
By the way the solid rocket boosters on the Space Shuttle are gimbled. As others have said simplicity and redundancy are important considerations in space design. Look up for example the Apollo Luner Orbiter engine design.
Slashdot Mirror
About 20 years ago at work we estimated the build cost of a piece of complicated equipment using a program called PRICE (I believed developed by RCA). Two of the key determining factors of cost were size and weight. We thought no way are weight and size that important. Over the years I have decided this not to be true. For similar items as weight goes down so does cost. Yes making stuff light weight means it is less rugged but cheaper. Think of hard drives. My first one was a 10 meg that weighed 5-10 lbs and took up the space that two 5-1/4" CD drives do today. These disks failed quite often and cost several hundred $ in the 1980s. Just bought a 120G byte drive on special for $49. Maybe it weighs 1/10 of the old drive.
A few years ago I went to a talk on making a position sensor for fire fighters. Remember GPS works poorly inside buildings. The idea was to use microaccelorometers to track the position of the firefighter inside a building. The author mentioned they placed the device in the heel of the boot. This way they could sense when the motion was stopped so they could rezero the accelerometers. Eliminating zero drift has always been a problem with guidance systems.
Methane from the DC sewage plant was used to heat the Naval Research Lab where I worked for years. One problem is the methane has quite a bit of air and CO2 in it so the facility where it is burned must be able to adjust the air to fuel ratio dynamically. We were next door to sewage plant so connecting to the methane source was no big deal. Of course when the wind came from the south we certainly knew who our next door neighbor was.
At what point is enough people enough? If we don't so something mother nature surely will. Actually we should have done a lot in the 1970's to reduce population growth, now I don't see anything but catastrophe in our future. Reducing consumption by 50% and doubling your population buys you nothing. Due to the lifetime of humans it is better late than never at seriously curbing population growth. Go to the CIA world fact book and look at children per woman for various countries. For example Iraq it is 4.18 and the population is young so even if the birth rate drops to about 2, there still will be a large increase in population. This means lots of young men have no hope or jobs and are attracted to the dark side. Another factoid: I remember reading a few years ago that if women in India only had two children from now on the population would level off at about two billion towards the end of this century. Is it possible for India to support twice its population, especially with end of cheap energy which equals cheap fertilizer and transporation? I don't think so. Maybe some of you can offer some hope but I don't see much.
The USMC developed the Dragon Eye and has been using it in IRAQ. See for example http://www.defense-update.com/products/d/dragoneye s.htm Note for simplicity there are no control surfaces. Control is performed by adjusting the power of the two electric motors. I have seen it fly and it is very quiet, which is the key for not being detected. Often at demos the sponsors were shown a TV screen showing themselves looking at the TV and then they would look up for it. The most useful TV camera is placed looking down and sideways and the GPS controller is programmed to have the Dragon Eye circle the target co-ordinates. This way the camera is always looking at the target of interest from different directions. It can fly a preprogammed pattern or be redirected by the person in charge. It also qualifies as a "model airplace" so you don't have to get the FAA involved in approving your flight plan.
Ok so HP went too far, not sure if law was broken, but George Keyworth's blabbing to a reporter started this. Considering that members of a board of directors often get paid big bucks for attending a few meetings, plus first-class expenses, they owe a fiduciary responsibility to the share holders they are working for and not divulging company information to a reporter. Often boards just go along with the CEO for fear of being kicked off the board and loosing the big bucks they get for little time or work. If you don't believe me check out the annual proxy statements for HP, in 2004 each member of the board received a $200k retainer. Not too bad.
The Eveready site, http://data.energizer.com/ shows that NiMH AA batteries have 30-40 milliohms internal resistence and can be used to put out 4A continuously. For the Li AA they don't recommend more than 3A burst mode, so in fact the NiMH batteries should be just as suitable. I always do carry some Li batteries as emergency spares, for one thing they have essentially unlimited life (90% power after 15 years!). NiMH batteries lose 1-2% of their charge per day so you need to charge every month to make sure they aren't too low on charge.
I believe it was the willingness of Hezbolah fighters to fight to the death that the difference. In the past other fighters would break and run under superior fire power. Now they hole up and take casualities. I would bet they learned tactics from Iraq. Well dug in infantry that is willing to fight will always cause a lot of casualities. Even if a someone in Hezbolah intercepted some messages, they would have to then communicate their response to many groups of fighters widely scattered. I doubt the control and communication was that good. Particulary when any movement of significant numbers would result in a punishing air strike.
Sometimes we make a straight forward problem hard. We can dig deep mines in geologically stable places. For example check out: http://en.wikipedia.org/wiki/Soudan_Mine (worth a tour). I think there is a whole industry of folks who get money from DOE to over research this problem. As a former researcher the ideal for you is to keep the funding stream going, never solve the problem just keep getting $$ for further studies. My only concern about burial would be a meteor strike ejecting the material into the atmosphere which could be catastophic.
Biggest money sink for folks your age is a car. Don't buy a new car. Find a used one. Certain brands don't have great resale value so take advantage of it, for example Chevy Malibu. Maybe a relative is trading in a car and will give you a good deal. Sure it may not be new or sexy, but the savings in depreciation, insurance, etc will be significant.
Don't forgo good experiences. Do some traveling in foreign countries, maybe spend the summer volunteering somewhere interesting. Sure these cost $$, but you will have the memories the rest of your life. This is in contrast to young adults who go to party places like Cancun over spring break. It's a lot cheaper to get drunk at college.
Good luck.
The shuttle has 3 auxillary power units. One is necessary to land. They are routinely tested while in space. If one fails they land as soon as possible. The APUs are not small, they are powered by a 100 horsepower turbine which is turned by decomposing hydrazine over a catalyst. Sometimes on good movies of the shuttle after it has landed you can see the heat waves from the hot gases (nitrogen, hydrogen, and a little ammonia) from the decomposing hydrazine coming straight up from the shuttle.
The larger thrusters and the rocket engine used by the shuttle in space are powered by methyl hydrazine reacting with nitrogen dioxide. These are hypergolic (burn on contact with each other) so no possiblity of them failing to ignite for a second or two then going boom which is possible with other fuels like hydrogen and oxygen. They are liquids at ambient temperatures so don't require cryogenic storage.
Hydrazine, N2H4, is a great rocket fuel. It is a liquid with similar boiling and freezing points to water -- but can explosively decompose (it is dangerous to measure its boiling point), is toxic at ppm levels, is carcinogenic (ie all the rats that breathed it got nasal cancer), causes skin burns. Like most amines it smells like rotten fish. Believe it or not there are people who believe that low levels in the blood is an anti cancer agent.
I think many users would want a system that would work from most any computer. For example, home, work, parents' house, etc. Couldn't the bank check the path of the packets it receives for suspect routing paths or maybe even unusual delays? It also could require you to confirm by email any unusual request.
I have worked with these lubricants. They have high vapor pressures and migrate all over all surfaces inside the volume where they are sealed. Probably good idea to have something equivalent to a saturated sponge inside the disk drive. Don't see the need for nanotubes. I would worry more about the motor bearings failing.
Other than Korea where large mine fields exist, US mines are designed to be applied remotely. These mines land on the surface and can have wires than are ejected after landing. Depending upon which wire is disturbed the mine will explode in the direction of that particular wire. The mines are designed to be put in front of an enemy to stop rapid movement, particularly at night time. They have self deactivating timers so do not pose a long term problem. In general this is well advanced technology and resources should not be applied to improving it when there are so many other pressing needs. Obviously this has no relevance in the war on terror unless you want to start mining Afghanistan (oops, USSR tried that and it didn't win their war).
Look we have had 120 flights, next one is STS-121. Challenger problem has been fixed so it doesn't count. So based on past performance one can say odds are about 1 in 100 something fatal may happen. I believe we only have about 20 more shuttle launches planned so odds are quite good nothing awful will happen. Maintaining the infrastructure is quite expensive so it's time to get on with it. We have three shuttles so there should be no problem finishing the station which is the only reason for maintaining the shuttle. I don't want to get into discussing the station as I start foaming at the mouth about what a waste of resources. Of course using a shuttle mission for something valuable to humankind, like prolonging the life of the space telescope is out of the question. I think NASA's motto has become "To unboldly not to go".
The real problem is that both Los Alamos and Lawrence Labs purpose was to design nuclear weapons which we know longer need to do. They are always searching for the need for a new weapon. A few years ago and still today they are pushing for a bunking busting nuke. Great way to generate lots of nuclear fallout from detonating the bomb in the ground. Right now they are looking to build a newer, higher reliability bomb. I am sure most of the scientists who would work on these projects know it is a great waste of resources. Yes, we need to keep a core expertese on nuclear weapons, but let's switch the major effort at these labs to deal with lack of cheap energy and so to be energy at any price.
Have the machine beep when an access cover is opened to a port to enable reprogramming. Opening the cover would require breaking tamper resistent tape and require a new code word to reprogram. The code word would be written to a write-once chip. The new code word must be different from prior ones. Code words would change daily and be available over the internet. The machine's Bios would require unsoldering a chip to change, on boot up it would display the last few code words for 10 seconds before beginning the reprogrammable code.
In the story the credit card company said the funds were held up due to security reasons. Thus I assume the credit card company was collecting interest during this time. Which means it is to their advantage to do this. It seems to me that credit card companies do all they can to nickel and dime you (more like 39.95 you) for example paying a day late. This annoys me since they get to charge you interest and would prefer you to be late. In so far as overboard security procedures it is an example of a win for Bin Laden. Probably does little for real security but bleeds our resources. Which by the way was in a recent statement as a goal of Al Queda
This is not new information about brain development. About 15 years ago, I attended a lecture about gifted students who under performed. The lecturer commented that often for males the ability to perform executive tasks did not fully develop until age 25. Executive skills are defined as being able to take a large task and break it in to smaller tasks that are manageable in order to accomplish the task. In contrast the ability to play a simple video game that requires rapid hand-eye coordination was fully developed by age 6.
But we have a selective breeding program to breed brighter humans. Our children are tested and the brightest ones and ones with sucessful parents (have $$) are placed together at time in their lives with a high probability of selecting a mate. Worked for me when I was in college.
I recall reading a story about the development of the IPOD. Several times Jobs looked at the prototype and said, "Change it, I don't like this feature." Because he controlled Apple this could happen even if it caused the schedule to slip and cost $$$. When you are right this is great. On the other hand Henry Ford stuck with the Model T too long, because he misread the consumer's needs.
Jobs certainly has the ability to judge what will make something become a unique product. Wonder if he will have the same skills at picking movies for Disney to produce.
For televisions with CRTs the filament is partially powered during standby. This allows faster warmup and increases the lifetime of the picture tube. Why, the thermal cycling of the electron gun cathode from ambient to red hot causes failure due to thermal stresses. It is better to keep the thermal stresses down by keeping the filament partially energized. Yes this consumes a few watts but from a consumer's point of view, this is a cost saver since failure of the picture tube will result in replacement of the entire TV set. Ditto for CRT monitors. Interestingly when I was in Mexico this summer I observed that most incandescent bulbs had been replaced by compact fluorescents. Finally one of the first actions of the Bush administration was to reduce the required efficiency standard for new home air conditioners. Doubly bad increases energy use and particularly peak energy use. In terms of energy policy as the old Hank Snow song says:
"Warning signs are flying by us but we pay no heed,
Instead of slowing down the pace we keep pickin' up the speed.
Disaster's getting closer every time we meet.
Doin' 90 miles an hour down a dead end street."
Most vehicles in space use a combination of thrusters and reaction wheels. Essentually a flywheel on each axis is spun up or down to rotate the vehicle. Eventually the wheel is moving too fast and a thruster is used to spin the vehicle so that the wheel can be slowed down. For moving the vehicle it is important to have the thrust vector point at the CG of the vehicle, else a torque is produced causing spinning which requires an additional thruster to compensate. By the way the solid rocket boosters on the Space Shuttle are gimbled. As others have said simplicity and redundancy are important considerations in space design. Look up for example the Apollo Luner Orbiter engine design.