FDM type 3d printers actually use around as much energy to construct things as an injection molding machine. Factoring in transport costs, they are probably a little bit better for the environment than injection molding. However, if you use a giant printer cartridge this probably changes, as they will get thrown away(seriously, who recycles cartridges anyway.
If no other body in the solar system is habitable, then make your own! Build a catapult on the moon, launch dirt to L2, and process it into a space colony. Many current space colony concepts have wall thicknesses on the order of that required to block said deadly space radiation and a sufficient ecosystem for closed loop life support.
Plus, you get the added benefit of continuous insolation and lots of space to set up solar panels(or radiators) so you can get lots of power for carrying out large industrial processes, like making more space colonies or doing various processes to keep the ecosystem running.
Now on the constant support for earth, what would you need from Earth that could not one day be made in space?
And seriously, having humanity stay on Earth till the sun burns out would be crazy.
Because then you need to engineer a microgravity drilling machine(and test it!), get it to your asteroid, de-spin your asteroid, and wrap it in elastic bands so your drill has 'gravity'. And you have to do all that before you put living quarters in. You also have the problem of moving it.
Hollowing out an asteroid is fairly complicated operation, but it's doable, just not in the near term.
Instead of hollowing the asteroid out, you could just scoop dirt off of it to make 'space sandbags.' Of course, we don't know very much about surface environment of asteroids, as of yet, there has been only one 'successful' asteroid sample return mission and it only returned a couple micron sized grains due to a sampler malfunction. As we don't have any mining devices that have been proven to work in microgravity, it might be better to scoop dirt from the Moon instead.
Of course, it might make more sense to use magnetic or electrostatic shielding to deflect said particles, they are charged after all.
He's not even using all Lego parts. And yes, there are indeed Lego propellors out there capable of generating propulsive thrust. And yes, you can even use an NXT smart brick to control a UAV.
But, worst of all it looks like he's committed one of deadliest Lego sins: irreversible modification of Lego bricks. How else are those motors staying on there?
When the governments of the world decide it's ok for civilians to own weapon's grade uranium.
TFA mentions that the reactor uses a 50 lb, which is about half the critical mass of uranium 235. In order for the core to maintain a fission reaction, even with the neutron shield in place, it's probably going to use weapons grade uranium.
There's been a pretty big effort to cut down on civilian usage of weapon's grade uranium(IE research reactors) and other fun fissile substances for fear of people making bombs from them.
Because NASA's running low on Plutonium and congress didn't approve the funds for NASA to make new Plutonium. It might be cheaper to retrieve this plutonium than to restart the whole plutonium production program.
NASA needs this plutonium for deep space missions. If we wanted to send a mission to a place like Europa, we'd need plutonium.
In fact the SNAP at the bottom of the ocean contains about as much plutonium as the RTG on the Curiosity rover.
While the initial 'cost' of a lithium battery is higher than the initial 'cost' of an internal combustion engine, the overall or "lifecycle" cost of a lithium battery is lower than that of an internal combustion engine.
That's pretty much the process that's been proposed by the USC contour crafting group proposed for doing rebar. Print a shell layer, drop in some modular rebar sections,then you fill up the shell with concrete so that your rebar connectors sticks out, and then repeat for the next layer. Another way to do reinforcement is to put a metal coil on your top layer and to print over it, so the coil gets embedded in the concrete. They've actually demonstrated this.
So why stop at just printing in colors? The contour crafting group has proposed putting in tiling, plumbing, electrical wiring, heaters, and strain gauges.
One approach to energy harvesting is to increase the efficiency of human walking and capture the energy the human would have expended walking. This has actually been demonstrated with an energy harvesting backpack. The amount of power the human should consume carrying the backpack and doing work on the generator was found to be more than the amount of power the human actually consumes.
So in other words, you still have to pay for your lunch, but you get more for your money.
Instead of throwing all that potentially valuable material into the pacific ocean, why not coral it all into one big "trash heap" and recycle it? After, it takes a lot more energy to put something into orbit than it does to move something to another orbit. At the very least, the trash heap could serve as a testing ground for space manufacturing processes.
The moon's gravity well is much shallower than Earth's
How much shallower you might ask? Well to get a pretty good idea, take a look at the Saturn V compared to the Apollo Lunar Module.
If you want to get more technical, the mass ratio, or initial mass of rocket(w/ propellant)/final mass of rocket minus propellant of a rocket increases exponentially with the amount of delta V you need.
So in other words you need 37* times "more rocket" to launch the same amount of mass to LEO from the Earth than it does from the Moon all other things being equal.
*
mass ratio =e^ (Delta V/ Exhaust velocity)
Delta V from Lunar surface to LEO 6.4
Delta V from Earth surface to LEO 10
e^10/e^6.4= 36.5982344
So according to this article it takes 40 people wearing these to purify 2 cubic meters of air in a minute. Each of which needs to be in direct sunlight as this probably relies on a photocatalyst. At this rate it'd probably be far more effective for these 40 people to bike or bus instead of commuting by car.(Of course, one could put the photocatalyst in the pavement, but that's already been done) And not to mention, given that these dresses likely use a photocatalytic mechanism, they do nothing about particulate pollution.
One reason the researchers might be suggesting a device that plugs into the phone, is that the microfluidic chip might require power. The detection process might require a PCR step(and yes, PCR can be done in 'CSI plot device' timeframes) this takes power. Bodily fluids are often quite viscous and might need to be pumped through the device. This would be especially necessary if part of the detection process involved mixing the bodily fluids with reagents as on small size scales(low Re, unless the fluid's going at the speed of sound) fluids don't mix, at least over reasonable time scales. This necessitates pumping your fluids to be mixed through micromixers, this takes power.
Also, at the very least a UV LED would be needed to show fluorescent markers.
Another attractive feature of additive manufacturing(3d printing refers to a specific additive manufacturing process) is that it's more efficient to additively manufacture exceptionally strong materials like TiAl6V4 and than it is to machine them. As exceptionally strong materials tend to be hard to machine, because they're exceptionally strong!
In addition, making "impossible" shapes might be advantageous. Hollow impossible to make cellular truss structures can have around twice the specific strength and specific stiffness of bulk material.
Also additive manufacturing can be used for production, in fact the new joint strike fighter could have additively manufactured parts in it. In addition this is being done because it's cheaper(as in ~$10 million cheaper) to make them this way.
Though, if you want a nice shiny surface finish you'll need to do post-processing....
You might want to reconsider growing algae for food, one research group at my university is investigating growing algae to produce sugar, so we don't have to cut down forests to grow sugarcane.
Also, I really hope those LED panels are solar powered. As solar powered LED panels emitting light at frequencies the algae uses can be far more efficient than growing algae in direct sunlight(even cheap solar panels are more efficient at solar conversion than algae).
One of the reasons bioluminescence gets researched by the military so much is because bioluminescent plankton create flashes of light that interfere with submarine laser communication systems. As plankton and submarine laser communication systems like to use wavelengths of light that transmit furthest in water(blue-green).
Just out of curiosity, does anyone know of any purging gas or artificial atmosphere applications that CANNOT under any circumstance use argon as a replacement for helium?
Why even bother rebottling it when you can scrub the CO2 out and add more oxygen just like they do in rebreathers? The helium, which is inert, would essentially be along for the ride each inhalation-exhalation breathing cycle.
Anyone care to do the energy density calculation on a mass basis?
Also I wonder how efficient the process is at converting mechanical energy to chemical energy?(it's almost like a gasoline engine running in reverse!)
There's very little in the way of standards for 3d printing, heck it's pretty hard to even get repeatable and precise prints. There are many different 3d printing processes and many have issues specific to them. The closest thing there is to a standard is the.stl(stereolithography) file format, pretty much every 3d printer accepts the.stl?" file format.
The state of the art in 3D printing software is proprietary software that runs on the computer hooked up to the machine and manages things specific to the machine. Sure there's open source 3d printing software, but that's for reprap and mostly hobbyists use that.
As far as multiple materials go, there's only one printer on the market capable of doing such a thing(objet Connex500) and any other printers capable of multiple materials are custom built or modified for research. Someone has proposed a.stl 2.0 file format?" for doing exactly this. It even includes method for defining objects made of repeating mesotructures like repeating trusses or frame cubes.
Material properties can be found in proprietary online databases or from the manufacturer and really more useful for the design part of things. By designing the structure and the way materials are distributed in a structure one can tailor the properties of the metamaterial that results. For example, one can make a titanium structure match the properties of bone(important when one's making an artificial hip joint), just by making it in the right shape.
Resolution/step size are printer specific parameters and are usually handled depending on whether you want a fast print or a high fidelity print. There are other printer specific parameters that might be worth including in the file format though. For example, in selective laser sintering and electron beam melting it's possible to change the micro-structure of the material by manipulating beam energy. Tailoring the microstructure along parts, would definitely be interesting. Though this is printer specific so it makes thing hard.
If one wants to make a universal 3d printer file format, one should probably make it like g-code.
Slashdot Mirror
FDM type 3d printers actually use around as much energy to construct things as an injection molding machine. Factoring in transport costs, they are probably a little bit better for the environment than injection molding. However, if you use a giant printer cartridge this probably changes, as they will get thrown away(seriously, who recycles cartridges anyway.
If no other body in the solar system is habitable, then make your own! Build a catapult on the moon, launch dirt to L2, and process it into a space colony. Many current space colony concepts have wall thicknesses on the order of that required to block said deadly space radiation and a sufficient ecosystem for closed loop life support.
Plus, you get the added benefit of continuous insolation and lots of space to set up solar panels(or radiators) so you can get lots of power for carrying out large industrial processes, like making more space colonies or doing various processes to keep the ecosystem running.
Now on the constant support for earth, what would you need from Earth that could not one day be made in space?
And seriously, having humanity stay on Earth till the sun burns out would be crazy.
Because then you need to engineer a microgravity drilling machine(and test it!), get it to your asteroid, de-spin your asteroid, and wrap it in elastic bands so your drill has 'gravity'. And you have to do all that before you put living quarters in. You also have the problem of moving it.
Hollowing out an asteroid is fairly complicated operation, but it's doable, just not in the near term.
Instead of hollowing the asteroid out, you could just scoop dirt off of it to make 'space sandbags.' Of course, we don't know very much about surface environment of asteroids, as of yet, there has been only one 'successful' asteroid sample return mission and it only returned a couple micron sized grains due to a sampler malfunction. As we don't have any mining devices that have been proven to work in microgravity, it might be better to scoop dirt from the Moon instead.
Of course, it might make more sense to use magnetic or electrostatic shielding to deflect said particles, they are charged after all.
He's not even using all Lego parts. And yes, there are indeed Lego propellors out there capable of generating propulsive thrust. And yes, you can even use an NXT smart brick to control a UAV.
But, worst of all it looks like he's committed one of deadliest Lego sins: irreversible modification of Lego bricks. How else are those motors staying on there?
Don't you mean an acoustic spanner, like this:
http://iopscience.iop.org/1367-2630/10/1/013018
It's been know for quite a while than one can generate a torque with soundwaves.
When the governments of the world decide it's ok for civilians to own weapon's grade uranium.
TFA mentions that the reactor uses a 50 lb, which is about half the critical mass of uranium 235. In order for the core to maintain a fission reaction, even with the neutron shield in place, it's probably going to use weapons grade uranium.
There's been a pretty big effort to cut down on civilian usage of weapon's grade uranium(IE research reactors) and other fun fissile substances for fear of people making bombs from them.
Because NASA's running low on Plutonium and congress didn't approve the funds for NASA to make new Plutonium. It might be cheaper to retrieve this plutonium than to restart the whole plutonium production program.
NASA needs this plutonium for deep space missions. If we wanted to send a mission to a place like Europa, we'd need plutonium.
In fact the SNAP at the bottom of the ocean contains about as much plutonium as the RTG on the Curiosity rover.
While the initial 'cost' of a lithium battery is higher than the initial 'cost' of an internal combustion engine, the overall or "lifecycle" cost of a lithium battery is lower than that of an internal combustion engine.
That's pretty much the process that's been proposed by the USC contour crafting group proposed for doing rebar. Print a shell layer, drop in some modular rebar sections,then you fill up the shell with concrete so that your rebar connectors sticks out, and then repeat for the next layer. Another way to do reinforcement is to put a metal coil on your top layer and to print over it, so the coil gets embedded in the concrete. They've actually demonstrated this.
So why stop at just printing in colors? The contour crafting group has proposed putting in tiling, plumbing, electrical wiring, heaters, and strain gauges.
See this paper for more:
http://craft.usc.edu/CC/Welcome_files/resources/AIC2004-Paper.pdf
One approach to energy harvesting is to increase the efficiency of human walking and capture the energy the human would have expended walking. This has actually been demonstrated with an energy harvesting backpack. The amount of power the human should consume carrying the backpack and doing work on the generator was found to be more than the amount of power the human actually consumes.
So in other words, you still have to pay for your lunch, but you get more for your money.
see "Harvesting Energy by Improving the Economy of Human Walking," for more
http://www.sciencemag.org/content/309/5741/1686.short
Instead of throwing all that potentially valuable material into the pacific ocean, why not coral it all into one big "trash heap" and recycle it? After, it takes a lot more energy to put something into orbit than it does to move something to another orbit. At the very least, the trash heap could serve as a testing ground for space manufacturing processes.
The moon's gravity well is much shallower than Earth's How much shallower you might ask? Well to get a pretty good idea, take a look at the Saturn V compared to the Apollo Lunar Module. If you want to get more technical, the mass ratio, or initial mass of rocket(w/ propellant)/final mass of rocket minus propellant of a rocket increases exponentially with the amount of delta V you need. So in other words you need 37* times "more rocket" to launch the same amount of mass to LEO from the Earth than it does from the Moon all other things being equal. * mass ratio =e^ (Delta V/ Exhaust velocity) Delta V from Lunar surface to LEO 6.4 Delta V from Earth surface to LEO 10 e^10/e^6.4= 36.5982344
According to "Sustainable Energy--- without the hot air," it's pretty much impossible to get anything but small gains in energy efficiency in aircraft.
So according to this article it takes 40 people wearing these to purify 2 cubic meters of air in a minute. Each of which needs to be in direct sunlight as this probably relies on a photocatalyst. At this rate it'd probably be far more effective for these 40 people to bike or bus instead of commuting by car.(Of course, one could put the photocatalyst in the pavement, but that's already been done) And not to mention, given that these dresses likely use a photocatalytic mechanism, they do nothing about particulate pollution.
One reason the researchers might be suggesting a device that plugs into the phone, is that the microfluidic chip might require power. The detection process might require a PCR step(and yes, PCR can be done in 'CSI plot device' timeframes) this takes power. Bodily fluids are often quite viscous and might need to be pumped through the device. This would be especially necessary if part of the detection process involved mixing the bodily fluids with reagents as on small size scales(low Re, unless the fluid's going at the speed of sound) fluids don't mix, at least over reasonable time scales. This necessitates pumping your fluids to be mixed through micromixers, this takes power. Also, at the very least a UV LED would be needed to show fluorescent markers.
Another attractive feature of additive manufacturing(3d printing refers to a specific additive manufacturing process) is that it's more efficient to additively manufacture exceptionally strong materials like TiAl6V4 and than it is to machine them. As exceptionally strong materials tend to be hard to machine, because they're exceptionally strong! In addition, making "impossible" shapes might be advantageous. Hollow impossible to make cellular truss structures can have around twice the specific strength and specific stiffness of bulk material. Also additive manufacturing can be used for production, in fact the new joint strike fighter could have additively manufactured parts in it. In addition this is being done because it's cheaper(as in ~$10 million cheaper) to make them this way. Though, if you want a nice shiny surface finish you'll need to do post-processing....
Absolutely, present the .STL files and I'll download one right now.
and statistics... Wouldn't want everyone freaking out after every low-n medical study that comes out(IE "SMOKING MAKES YOU HEALTHIER!").
Perhaps this is yet another one of Steve Wozniak's pranks...
You might want to reconsider growing algae for food, one research group at my university is investigating growing algae to produce sugar, so we don't have to cut down forests to grow sugarcane. Also, I really hope those LED panels are solar powered. As solar powered LED panels emitting light at frequencies the algae uses can be far more efficient than growing algae in direct sunlight(even cheap solar panels are more efficient at solar conversion than algae).
One of the reasons bioluminescence gets researched by the military so much is because bioluminescent plankton create flashes of light that interfere with submarine laser communication systems. As plankton and submarine laser communication systems like to use wavelengths of light that transmit furthest in water(blue-green).
Just out of curiosity, does anyone know of any purging gas or artificial atmosphere applications that CANNOT under any circumstance use argon as a replacement for helium?
Why even bother rebottling it when you can scrub the CO2 out and add more oxygen just like they do in rebreathers? The helium, which is inert, would essentially be along for the ride each inhalation-exhalation breathing cycle.
Anyone care to do the energy density calculation on a mass basis? Also I wonder how efficient the process is at converting mechanical energy to chemical energy?(it's almost like a gasoline engine running in reverse!)
There's very little in the way of standards for 3d printing, heck it's pretty hard to even get repeatable and precise prints. There are many different 3d printing processes and many have issues specific to them. The closest thing there is to a standard is the .stl(stereolithography) file format, pretty much every 3d printer accepts the .stl?" file format.
The state of the art in 3D printing software is proprietary software that runs on the computer hooked up to the machine and manages things specific to the machine. Sure there's open source 3d printing software, but that's for reprap and mostly hobbyists use that.
As far as multiple materials go, there's only one printer on the market capable of doing such a thing(objet Connex500) and any other printers capable of multiple materials are custom built or modified for research. Someone has proposed a .stl 2.0 file format?" for doing exactly this. It even includes method for defining objects made of repeating mesotructures like repeating trusses or frame cubes.
Material properties can be found in proprietary online databases or from the manufacturer and really more useful for the design part of things. By designing the structure and the way materials are distributed in a structure one can tailor the properties of the metamaterial that results. For example, one can make a titanium structure match the properties of bone(important when one's making an artificial hip joint), just by making it in the right shape.
Resolution/step size are printer specific parameters and are usually handled depending on whether you want a fast print or a high fidelity print. There are other printer specific parameters that might be worth including in the file format though. For example, in selective laser sintering and electron beam melting it's possible to change the micro-structure of the material by manipulating beam energy. Tailoring the microstructure along parts, would definitely be interesting. Though this is printer specific so it makes thing hard.
If one wants to make a universal 3d printer file format, one should probably make it like g-code.