I have a graduate degree in Mechanical Engineering. I also have a smattering of formal computer science education. This combination has proved invaluable. I basically work in automation research now, and the number of people in this field that "know" how to program but can't prove an algorithm or build an abstraction layer is staggering. The software they turn out is awful. The number of people that can design good software, but don't understand how to control a machine in an industrial environment is also staggering.
I don't write software (except for Matlab), but the understanding that I have of the CS field lets me communicate effectively with the people that don't understand machines, but do develop software. This has given me an excellent advantage in my position, and created a rather exciting career.
The moral: even if you don't go full out new degree in CS, a fair amount of education in the field could create the opportunities for a career change that you are looking for. Maybe.
I would wager that it will go the fate of Coupling. My wife and I very much enjoy the BBC show Coupling. When NBC ran it, it just wasn't the same. I dunno, maybe Jeff just wasn't quite right. Maybe we just got used to the British actors and actresses. The script and story were virtually unchanged, but somehow it just sucked over here. I look forward to the new series of Coupling when it hits BBC America, but I'm guessing Office in the States will just lack in that same un-definable way.
Checking USPS, certified mail is $2.30+postage and registered mail is minimum $7.50+postage. $0.80 seems like a good deal compared. Remember, it's not what it costs to produce, it what the market is willing to pay.
Aircraft are shaped like a tube because they are thin walled pressure vessels (like a helium tank). They have round noses and rounded aft pressure domes, usually hidden by the outer mold line skin. This is so that the hoop stress from the internal pressure is evenly distributed and you don't have stress concentrations in the corners which would ultimately lead to fatigue cracks and failure. If it were not for the pressure problem, a prismatic airplane (think shaped like a bullet train) would be a heck of a lot more comfortable for the passengers.
(flame bait ahead)
I love being a "real" engineer when all my friends are CS geeks.
O.K. I reached up to my bookcase and grabed Robert Norton's "Machine Design: an integrated approach" I will now commence to quote liberally. Nobody is really going to read this so far into the tree, so what the heck.
7.2 Mating surfaces
When two surfaces are pressed together under load, their apparent area of contact Ar is afffected by the asperities present on their surfaces and is more difficult to accurately determine. The tops of the asperities will initially contact the mating part and the initial area of contact will be extremely small. The resulting stresses in the asperities will be very high and can easily exceed the compressive yield strength of the material. As the mating force is increased, the asperity tips will yield and spread until their combined area is sufficient to reduce the average stress to a sustainable level, i.e., some compressive penetration strength of the weaker material.
The real area of contact can then be estimated from Ar = F/Sp = F/3Syc. Note that the contact area for a material of particular strength under a given load will be the same regardless of the apparent area of the mating surfaces.
7.3 Friction
Note that the real area of contact Ar is independent of the apparent area Aa that is defined by the geometry of the mating parts. This is the reason that Coulomb friction between two solids is also independent of th aapparent area of contact Aa. The equation for coulomb sliding friction is f=uF. (Some good stuff on how plough force affects friction which I'm not typing out)
Effect of roughnes on Friction
One might expect the surface roughness to have a strong influence on the friction coefficient. Tests show only a weak relationship, however. At extremely smooth finishes, below about 10uin Ra, the coefficient of friction does increase by as much as a factor of 2 due to an increase in the real contact area. At very rough finishes, above about 50uin Ra, the coefficient of friction also increases slightly due to the energy needed to overcome asperity interferences (plowing) in addition to shearing their adhesion bonds.
Effect of Velocity on Friction
Kinetic Coulomb friction is usually modeled as being independent of sliding velocity V except for a discontinuity at V=0 where a larger, static coefficient is measured. In reality, there is a continuous, nonlinear drop in u with increasing V. This function is approximately a straight line when pltted against the log of V and its negative slope is a few percent per decade. It is believed that some of this is due to the increased interface temperatures resulting from the higher velocities reducing the material's shear yeild strength.
Rolling Friction
When a part rolls on another without any sliding, the coefficient of friction is much lower in the range of 5e-3 to 5e-5. The friction force will vary as some power of the load (from 1.2 to 2.4) and inversely with the radius of curvature of the rolling elements. Surface roughness does have an effect on rolling friction and most such joints are finished by grinding to minimize their roughness. High hardness materials are usually used to obtain the needed strengths and promote smooth ground finishes. There is little variation of rolling friction with velocity.
At work we needed a large quantity (~10 lbs.) of the stuff for an experiment. We we able to get a "sample" quantity directly from DOW in a 50 lb. bucket. We gave half of it to the salesman for his kids, leaving us with about 25 lbs. 10 lbs. for the experiment, and 15 lbs. to make into a giant silly putty ball that we then proceeded to bounce in the lab. BAD IDEA. It's hard to roll a good sphere that size, so the thing bounced chaoticly about the lab almost taking out a computer monitor. Still, it is impressive to see that much silly putty at once.
Slashdot Mirror
I have a graduate degree in Mechanical Engineering. I also have a smattering of formal computer science education. This combination has proved invaluable. I basically work in automation research now, and the number of people in this field that "know" how to program but can't prove an algorithm or build an abstraction layer is staggering. The software they turn out is awful. The number of people that can design good software, but don't understand how to control a machine in an industrial environment is also staggering.
I don't write software (except for Matlab), but the understanding that I have of the CS field lets me communicate effectively with the people that don't understand machines, but do develop software. This has given me an excellent advantage in my position, and created a rather exciting career.
The moral: even if you don't go full out new degree in CS, a fair amount of education in the field could create the opportunities for a career change that you are looking for. Maybe.
I would wager that it will go the fate of Coupling. My wife and I very much enjoy the BBC show Coupling. When NBC ran it, it just wasn't the same. I dunno, maybe Jeff just wasn't quite right. Maybe we just got used to the British actors and actresses. The script and story were virtually unchanged, but somehow it just sucked over here. I look forward to the new series of Coupling when it hits BBC America, but I'm guessing Office in the States will just lack in that same un-definable way.
Depends on the language.
Who writes 8 x 10^9? How quaint. 8e9 is so the way to go.
Checking USPS, certified mail is $2.30+postage and registered mail is minimum $7.50+postage. $0.80 seems like a good deal compared. Remember, it's not what it costs to produce, it what the market is willing to pay.
I'd even wager that the odds of two breaking are exactly the square of the odds of one breaking.
Because you can't fit a binder of blueprints into a 8-1/2" wide shredder.
But what is the warranty on a printer? Something like 90 days. Why the hell should I care if my nearly expired warranty is voided?
So, this program doesn't have a coherent plan I guess.
Aircraft are shaped like a tube because they are thin walled pressure vessels (like a helium tank). They have round noses and rounded aft pressure domes, usually hidden by the outer mold line skin. This is so that the hoop stress from the internal pressure is evenly distributed and you don't have stress concentrations in the corners which would ultimately lead to fatigue cracks and failure. If it were not for the pressure problem, a prismatic airplane (think shaped like a bullet train) would be a heck of a lot more comfortable for the passengers. (flame bait ahead) I love being a "real" engineer when all my friends are CS geeks.
7.2 Mating surfaces
When two surfaces are pressed together under load, their apparent area of contact Ar is afffected by the asperities present on their surfaces and is more difficult to accurately determine. The tops of the asperities will initially contact the mating part and the initial area of contact will be extremely small. The resulting stresses in the asperities will be very high and can easily exceed the compressive yield strength of the material. As the mating force is increased, the asperity tips will yield and spread until their combined area is sufficient to reduce the average stress to a sustainable level, i.e., some compressive penetration strength of the weaker material.
The real area of contact can then be estimated from Ar = F/Sp = F/3Syc. Note that the contact area for a material of particular strength under a given load will be the same regardless of the apparent area of the mating surfaces.
7.3 Friction
Note that the real area of contact Ar is independent of the apparent area Aa that is defined by the geometry of the mating parts. This is the reason that Coulomb friction between two solids is also independent of th aapparent area of contact Aa. The equation for coulomb sliding friction is f=uF. (Some good stuff on how plough force affects friction which I'm not typing out)
Effect of roughnes on Friction
One might expect the surface roughness to have a strong influence on the friction coefficient. Tests show only a weak relationship, however. At extremely smooth finishes, below about 10uin Ra, the coefficient of friction does increase by as much as a factor of 2 due to an increase in the real contact area. At very rough finishes, above about 50uin Ra, the coefficient of friction also increases slightly due to the energy needed to overcome asperity interferences (plowing) in addition to shearing their adhesion bonds.
Effect of Velocity on Friction
Kinetic Coulomb friction is usually modeled as being independent of sliding velocity V except for a discontinuity at V=0 where a larger, static coefficient is measured. In reality, there is a continuous, nonlinear drop in u with increasing V. This function is approximately a straight line when pltted against the log of V and its negative slope is a few percent per decade. It is believed that some of this is due to the increased interface temperatures resulting from the higher velocities reducing the material's shear yeild strength.
Rolling Friction
When a part rolls on another without any sliding, the coefficient of friction is much lower in the range of 5e-3 to 5e-5. The friction force will vary as some power of the load (from 1.2 to 2.4) and inversely with the radius of curvature of the rolling elements. Surface roughness does have an effect on rolling friction and most such joints are finished by grinding to minimize their roughness. High hardness materials are usually used to obtain the needed strengths and promote smooth ground finishes. There is little variation of rolling friction with velocity.
It's probably a design patent, not a method patent. Design patents just keep people from copying your design.
At work we needed a large quantity (~10 lbs.) of the stuff for an experiment. We we able to get a "sample" quantity directly from DOW in a 50 lb. bucket. We gave half of it to the salesman for his kids, leaving us with about 25 lbs. 10 lbs. for the experiment, and 15 lbs. to make into a giant silly putty ball that we then proceeded to bounce in the lab. BAD IDEA. It's hard to roll a good sphere that size, so the thing bounced chaoticly about the lab almost taking out a computer monitor. Still, it is impressive to see that much silly putty at once.