John Cuthber
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Posts posted by John Cuthber
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thanks man ill get to work.
"We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard".
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The brain can say if some statements are true but there are some about which we are not sure (not least, the quesstion that forms the title of this thread).
I could write a program that, if asked "Is the sum of 2 even numbers an even number?" would reply "Yes".
It may well be the the fact that we con often answer general questions like this means that we are not turing machines- but it could be that we are somehow programed to recognise some questions and give the right answer.
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"btw this plastic is also known as PET"
Yes.
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Get 2 plates of glass, put thin spacers between them. Seal round most of the edges to give a big flat very thin glass box.
Dissolve the sunscreen up in something- alcohol will probably work, and pour it into the gap between the plates.
Seal the last bit of the edge and you have a filter with a known amount of sunscreen distributed evenly over a known area. Just getting hold of the active ingredient in the sunblock might make it easier to get a clear solution.
Incidentally, as has been pointed out before, glass blocks a lot of UV. Big sheets of fused quartz are going to cost a fortune.
You might want to look up the UV spectra of, for example, perspex, and PVC. Perspex won't survive alcohol indefinitley, but it might give you time to grow some plants.
I'd not like to be there when someone trys to spin coat a big glass plate.
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Once he has done it outside a hundred times then you might think about saying it's safe enough to do inside.
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You listed RDX twice. Also, to add on to what nitric said RDX is also incredibly stable. Apparently C-4, consisting primarily of RDX, can be shot with a rifle and lit on fire without detonating.
Also, nice point with the alcohol.
I was just testing to see if anyone read the list. The RMX should be HMX.
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Isn't the answer to this question "Yes, I have one between my ears"?
I think we need a definition of computer as well as consious.
If my brain (and as much of the nervous/ sensory system as is required) can be mapped onto a turing machine then a computer can be consious (at least as much as I can).
If not then it can't (at least for the definition of consious that says it means "acting like a brain").
Is the brain a turing machine?
If not, what does it do that a turing machine can't?
(and I know that one possible answer to that is that a brain can be consious- but that's begging the question).
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You can recrystalise it from salt substitue and that will get you a pure enough product for most things. What do you want it for?
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Ironiser,
Trust me, it does make sense, and you can just think about it. The problem is that you need a lot of background knowledge before you can do that- not least you need to understand a lot of quantum mechanics.
In the meantime, have fun trying to live your life without having to remember stuff.
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Aparently about 320% of people have voted in this poll, so I guess there must be a God after all (or the software has screwed up somehow)
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He can pay as much attention as he likes in class. That equation is just plain wrong. The product of the reaction is acetic acid, so googling it might not help.
There's another way of balancing equations that might help here.
Pretend that the Cr(VI) is present as CrO3 (not a million miles out for acid dichromate) and that it's converted to Cr2O3.
4 CrO3 --> 2 Cr2O3 + 3O2
Then write out the oxidation as if its being burned in oxygen
C2H5OH + (however many) O2 --> CO2 + H2O
Each O2 requires 4/3 CrO3
From that you can get the stoiciometry of the reaction.
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Well, you might be a student, but I think you are right. NOC is not a stable compound and it's not a radical I have ever heard of.
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"None of the above" would be a good option.
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It's difficult to put them in any real order but I wasn't exactly happy working with flurosulphonic acid perchloric acid, HF, bromine, nitroglycerine, PETN, TNT, RDX, picric acid, EGDN, tetryl, RMX, RDX, tetrachlorodibenzodioxin or ricin.
On the other hand I think more people are killed by alcohol than by all those "nasty" chemicals put together.
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He's going down hill. Even with the engine switched off he would still roll down the hill and accelerate until the wind resistance (etc) was dissipating energy as fast as gravity was providing it.
The engine isn't the only power source here.
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Sucralose is a calorie free sweetner so its not going to provide energy.
Taurine and speed have practically nothing in common.
The most likely effect of all these added chemicals is to give you really expensive urine, that's where the end up.
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Usually, but not always.
At the maximum the change in absorbtivity with wavelength is small so errors in the wavelength don't matter so much.
On the other hand, if there's a "valley" in the spectrum you can use that instead.
Of course, the sensitivity will be lower, but that might be an advantage sometimes. If the solution is very concentrated you might want to use some wavelength where the stuff absorbs less strongly- that way you don't need to dilute the sample to get it within the linear range of the spectrometer.
Also if the solution has some impurity in it that also absorbs at the maximum, but not somewhere else in the spectrum you can sometimes measure the concentration without interference from the impurity.
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This has been discussed at some length on another site.
http://www.thenakedscientists.com/forum/index.php?topic=17926.0
The problem is not with the physics, but with the poster's interpretation.
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Heating copper to red heat in air will coat it with the oxide (mainly CuO, some Cu2O). Quenching it in water will make a lot of the oxide fall off as flakes. With a bit of copper pipe, a gas stove and a bucket of cold water you should be able to make some quite easily. If you want a lot this will get tedious.
Adding copper compounds to H2O2 generally makes it decompose to water and O2 - not a lot of use.
What do you want the stuff for? If it's for colouring flames then the quality of the product from heating copper in air is probably good enough.
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DMSO doesn't smell much but one of its uses is as an oxidant. The by product (the sulphide) really stinks.
I think a scrubber with an amine might be a better idea- such scrubbers are used for cleaning up gas streams anyway so the technology isn't new. How fast MeI reacts with, for example, ethanolamine, is another matter.
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The heat of neutralisation in water is the the same for all acids so you could do this reaction in solution. Sb(V) is fairly oxidising so I suspect the product would be Fe(III) hexafluoroantimonate, even if you started with Fe(OH)2.
If someone said "What happens if I add dilute perchloric acid to Fe(OH)3 ?" would anyone be predicting anything exciting?
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taurine is an analogue of speed as far as i recall.
In what way?
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I know that people have extracted DNA from old things but that Dinosaur DNA from amber remains in the realms of science fiction.
What's the oldedts DNA found and is it reasonable to assume that viruses might last roughly that long?
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Zero? Does it not seem common sense that the sum of all numbers in any sequence would be bigger than the biggest number in the sequence you're summing up?
Not to me.
For every positive number there is a negative number and they form a pair whose sum is zero.
Then you sum all the zeros and get zero.
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the value per kg of PETE
in The Lounge
Posted
Oops, I read it as a question. Never mind, I bumped your thread for you.
Anyway, from here
http://www.bplans.com/plastics_recycling_business_plan/market_analysis_summary_fc.cfm
"The Company has chosen its target markets because recycled PET (RPET) is in high demand as flake resin by converters, as roll stock sheet used to produce high visibility packaging and as high strength strapping for the lumber industry. Sales are price-sensitive, so that proximity to markets and feed stock source provide a competitive edge. Replay Plastics identified an opportunity to take advantage of both circumstances in the western United States.
RPET Flake
Total market demand is reported as 1.2 billion pounds per year. Since only 800 million pounds are processed in the USA, consumers are forced to look at wide spec virgin PET (virgin resin that is outside of spec but still usable) which is normally sold at a discount to virgin prices, but still higher than recycled (RPET) pricing. Some manufacturers are also forced to import materials from Mexico, India and South America. Some converters are being forced to use more expensive virgin resin.
The current pricing for virgin resin is $0.65-0.73 per lb. and $0.42-.53 for RPET flake. The spread between the two has traditionally been maintained at approximately $0.20 per lb.
PET Film & Sheet
The total reported market of extruded film and sheet is 872 million pounds, of which identified industry usage of RPET is 160 million pounds.
The reported market demand (to replace virgin PS, PVC and PET) if RPET was available is estimated at 1 billion pounds.
Current pricing for RPET sheet is $0.70-0.79 per lb.
RPET Strapping
The total reported domestic plastic strapping market is 240 million pounds. Of this market, industry usage of virgin polypropylene is 132 million pounds and of PET is 108 million pounds.
It is generally accepted in the industry that less expensive strapping made from RPET could not only take over the polypropylene strapping market, but convert as much of the much larger and more expensive steel strapping market as RPET strapping was available.
Current pricing for RPET strapping is $0.90 -1.08 per lb."
Slightly more really really helpful I hope.