Merged Thread to Discuss The Excellent Analysis of Jones latest paper

[Dave Rogers]

Dr. G. informs me that sputtering is very expensive. (Page 3, here.) It would cost hundreds of dollars to coat just 1 teaspoon.

It's not the expense that's the problem with sputtering. I use a sputtering coater regularly, that has the capacity to coat a 4" sample of silicon. It's a high vacuum chamber in an installation about six feet long, seven feet high and three feet deep, and the sample is introduced through a load-lock big enough to accept about an eight-inch by three-inch cross-section. I'm not even going to bother working out what sort of installation would be needed to sputter-coat material onto the columns of a WTC tower; it's such a ridiculous notion, it's not worth the time.

Dave

 

[Dave Rogers]

Some comments on thermite and energy density

I want to reply to a couple of comments that metamars made in the closed thread on Jones's Bentham paper, and I think this is probably the appropriate place to do it. I was away over Easter, so it took a while to catch up, but the specific post is at http://www.internationalskeptics.com/forums/showthread.php?postid=4599311#post4599311.

First of all, I think this may have been covered, but I'd like to put it to bed:

High energy release per unit mass suggests that the chips don't contain the oxygen needed for combustion, because that tends to limit the energy density.

Don't you have this backwards?

No, I have it the right way round. The Wikipedia article on energy density (http://en.wikipedia.org/wiki/Energy_density) explains it similarly:

Energy densities excluding oxidisers This table lists energy densities of fuels that require external oxidisers, such as oxygen. These figures do not take into account the mass and volume of the oxygen required for the chemical reactions, as it is assumed to be freely available and present in the atmosphere. Such systems give a higher energy density than an equivalent system that must hold its own oxidiser.

Therefore thermite, which holds its own oxidiser, has a lower energy density, at around 4kJ/g, than combustible materials that don't contain their own oxidisers, for example kerosene at around 43kJ/g.

Now the rather more complex point:

Again, this has been corrected several times in this thread. The energy density of "super thermite" is exactly the same as that of the same thermite composition with a greater particle size.

Wrong, again. See figure 7.3, p. 114, in Grainier's thesis, COMBUSTION CHARACTERISTICS OF A1 NANOPARTICLES AND NANOCOMPOSITE A1+MoO3 THERMITES, for Al/MoO3 thermite. The difference isn't even 1 order of magnitude, but it's not close to "exactly the same", either. Apparently, you're thinking of perfect reactions.

Let's take a look at the figure in question, reproduced here under fair use conditions as a small part of the above referenced work for research.



It's not entirely clear, but look at the Y axis. The highest value quoted is less than 4000J/g, the figure for the energy density of thermite.

Now, let's address the comment "Apparently you're thinking of perfect reactions". I'm using the term "energy density", which is perfectly clear, and is equal to the amount of energy that can be released in a 100% efficient reaction. What we can see from Grainier's thesis is that the amount of energy released by any thermite formulation is less than its energy density, but that the efficiency of energy release is greater for smaller particle sizes. This is completely consistent with the fact that the energy density of thermite is independent of particle size, as I originally pointed out.

Now, going back to the paper, DSC results indicate energy releases of 1.5, 3, 6 and 7.5kJ/g from four samples, with the comment made that the underlying grey layer is included in the mass but does not react, so does not contribute to the heating. We can assume, therefore, that the minimum possible value of energy density of the material believed to be thermite is 7.5kJ/g, or nearly twice the energy density of pure thermite. This is assuming a perfect reaction, and assuming that there is no inert grey layer on the sample giving the highest energy release; if either of these assumptions is invalid, then the actual energy density must be greater. The conclusion is simple and inescapable: the material is not thermite.

At this point a peer-reviewer capable of referring to Wikipedia would have returned the paper to its authors for a major revision. In particular, the use of an air ambient for the DSC experiments, as specifically stated on the fourth page of the paper, invalidates any possible conclusion concerning a thermite reaction, as Sunstealer has repeatedly pointed out. Again, there is a simple and inescapable conclusion: this paper was not competently peer-reviewed.

Dave

 

[metamars]

It's not the expense that's the problem with sputtering. I use a sputtering coater regularly, that has the capacity to coat a 4" sample of silicon. It's a high vacuum chamber in an installation about six feet long, seven feet high and three feet deep, and the sample is introduced through a load-lock big enough to accept about an eight-inch by three-inch cross-section. I'm not even going to bother working out what sort of installation would be needed to sputter-coat material onto the columns of a WTC tower; it's such a ridiculous notion, it's not worth the time.

Dave

I wasn't thinking of sputter coating steel columns. I was suggesting sputter coating Silicon nano-sized platelets, with Aluminum. The Al/Si platelets which result would then be incorporated into nanothermite as a sol gel. The sol gel layer is, in turn deposited on a ferrous layer.

Whether you can essentially cut up the resulting nanofoil into little chips (so as to make them immersible, thus thinly spreadable, in a solution that you can paint on to a column) is something that I don't particularly feel confident speculating on, but I will guess that it's probably not much harder than cutting aluminum foil into little pieces. Whether or not the stuff would fall apart under the stress of cutting, I have no idea.

I suspect you would only need sputter coating for precise control of thickness and geometry, while depositing Al by vaporizing it first (assuming this would even work) would give more uneven results.

 

[Sunstealer]

Exactly the same? Where is the proof of this? Please show us some examples.

Well it's quite simple - EDS/EDX/XEDS can only show what elements are present. If no outside element has been introduced then the exact same elements are present therefore the spectra will be the same (assuming the same mode for the beam is used).

This will take you some time to read but it covers everything you will need to know. http://books.google.co.uk/books?id=...X&oi=book_result&ct=result&resnum=4#PPA555,M1

XRD? You mean X-ray diffraction? What exactly are you trying to say here with "show the difference"?

Edited by Cuddles: 

Edited for topic for moderated thread.

Yes x-ray diffraction.

What I am trying to say is that the two methods are completely different in the way they operate and the diagrams they produce. X-ray crystallography will produce a diffraction pattern. It's from this diffraction pattern that you can tell what the crystal structure is and therefore identify the material. Many materials will have very similar XEDS spectra because they are made from similar elements however, we cannot tell exactly what the material is because XEDS cannot tell us what compounds are present. XRD will do this and it's able to distinguish different compounds that are made from similar elements.

FTIR (Fourier Transmision Infra Red spectroscopy) will do the same thing with organic compounds.

Again here are some basic information http://epswww.unm.edu/xrd/xrdbasics.pdf

 

[Sunstealer]

I wasn't thinking of sputter coating steel columns. I was suggesting sputter coating Silicon nano-sized platelets, with Aluminum. The Al/Si platelets which result would then be incorporated into nanothermite as a sol gel. The sol gel layer is, in turn deposited on a ferrous layer.

Whether you can essentially cut up the resulting nanofoil into little chips (so as to make them immersible, thus thinly spreadable, in a solution that you can paint on to a column) is something that I don't particularly feel confident speculating on, but I will guess that it's probably not much harder than cutting aluminum foil into little pieces. Whether or not the stuff would fall apart under the stress of cutting, I have no idea.

I suspect you would only need sputter coating for precise control of thickness and geometry, while depositing Al by vaporizing it first (assuming this would even work) would give more uneven results.

I did infact Lol when I read your idea to sputter coat, but that's only because I know what a typical type of machine is used for sputter coating (just like Dave) and how amusing it would be for someone to have to sputter coat kilograms of material in such a machine. Sputter coating is also directional in that the spray is directed down wards onto the target, the underside is not coated. I can't even imagine a huge machine to sputter coat large quantities of powder ensuring a coating around the particle.

It's a non-starter tbh.

 

[Dave Rogers]

I wasn't thinking of sputter coating steel columns. I was suggesting sputter coating Silicon nano-sized platelets, with Aluminum. The Al/Si platelets which result would then be incorporated into nanothermite as a sol gel. The sol gel layer is, in turn deposited on a ferrous layer.

OK, that makes a little more sense, but it seems rather pointless. What you're aiming to do is produce a precise Al:Si ratio, which could be done much more easily by simply combining the right amounts macroscopically and grinding to nanoscale dimensions. Handling very thin silicon platelets isn't exactly trivial either. It doesn't sound like a scalable technique, given that you're talking about tons of material.

I suspect you would only need sputter coating for precise control of thickness and geometry, while depositing Al by vaporizing it first (assuming this would even work) would give more uneven results.

No, Al evaporation by e-beam is as routine as sputtering and uses a rather smaller piece of equipment. Still not very scalable, but not as bad as sputtering.

It's all reasoning the wrong way, though. You're saying "This is what we see, how can we construct a backward argument that leads to thermite". If you start from the requirement to coat columns with nanothermite sol-gel and work forwards, there's no way you'll end up with a solution that involves planar coatings. No sane engineer would even consider producing a precisely dimensioned multilayer that was then supposed to be ground up and sprayed on; bulk mixing followed by grinding is inevitably orders of magnitude cheaper, simpler and more reliable.

Dave

 

[Dave Rogers]

I did infact Lol when I read your idea to sputter coat, but that's only because I know what a typical type of machine is used for sputter coating (just like Dave) and how amusing it would be for someone to have to sputter coat kilograms of material in such a machine.

The machine in your link isn't a sputter coater, it's a small benchtop evaporator for gold-coating SEM samples. A decent sized sputter coater is much, much bigger.

Dave

 

[metamars]

OK, that makes a little more sense, but it seems rather pointless. What you're aiming to do is produce a precise Al:Si ratio, which could be done much more easily by simply combining the right amounts macroscopically and grinding to nanoscale dimensions.

I assume that a "precise Al:Si ratio" is a very secondary goal. (It turns out that Si can help make thermite into a eutectic, optimal content 11%, IIRC). Rather, if the idea is to how to make an incendiary which is also explosive, to some degree, you need intimate mixing which nanoscale affords. Also, if you look at MODELING THE MELT DISPERSION MECHANISM FOR NANOPARTICLE COMBUSTION, you see that heat diffusion cannot explain the the extremely fast ignition times and much higher flame propagation velocities you get with nano, vs. micron. The author supports the melt dispersion mechanism as an explanation for these nano-scale (dynamic) properties.

Whether or not you agree with the author regarding melt dispersion, he a) used the idea to good effect in his calculations and b) showed experimentally that "flame propagation velocity depends sensitively on relative particle size, relative particle size distribution, oxide shell formation temperature, and shell strength." b) constitutes a set of facts that care neither for your opinion, nor mine.

I have no idea about control of oxide shell formation temperature in any grinding process, but I have a hard time believing that you could control shell strength via any grinding (and filtering, if necessary) process, whatsoever. I also have a hard time believing that you could effectively or at least efficiently control relative particle size and relative particle size distribution in a grinding process (and filtering, if necessary).

Feel free to enlighten us to the contrary.

Handling very thin silicon platelets isn't exactly trivial either. It doesn't sound like a scalable technique, given that you're talking about tons of material.

This subject is totally beyond both my area of expertise, and desire to google-vestigate. I have a cousin who is a chemical engineer, maybe he could shed some light on this question, though I don't see him much these past few years. A better option is to start knocking on doors at local university chemical engineering departments. You may be completely correct on this point, and I wouldn't be surprised, but I don't think I'll be looking into this in the near future, if ever.

It's all reasoning the wrong way, though. You're saying "This is what we see, how can we construct a backward argument that leads to thermite". If you start from the requirement to coat columns with nanothermite sol-gel and work forwards, there's no way you'll end up with a solution that involves planar coatings.

Not planar coatings, multi-layer planar chips that can be incorporated into a paint.

No sane engineer would even consider producing a precisely dimensioned multilayer that was then supposed to be ground up and sprayed on;

Not ground up - cut up. There's a huge difference. (Well, not if the stuff is crumbly. )

bulk mixing followed by grinding is inevitably orders of magnitude cheaper, simpler

Only if you don't care about the higher power afforded by nano versions, not to mention the higher energy density. Also, in a black op of the scale of 911, cost is practically a non-factor. A single F-22 will be selling for $150 - $200 million dollars, by way of comparison.

and more reliable.

Dave

More reliable as an incendiary, to make kerosene-like jet fuel look like napalm going off, in 1/3 of a second?? No way.

 

[T.A.M.]

Apparently the authors of the article, or at least one or two, are getting agitated with other scientists and science followers, daring to criticize their paper/analysis.

Apparently J Courley has asked Dr. Greening to stop with the "Grenades" and to stop with the "armchair ideas".

Dr. Greening:

That is all I am trying to say ... but for this effort I have now been requested (by e-mail) to stop pestering the authors with these "armchair ideas" and go and do my own analysis on my own samples.

Well actually no one has told me to stop e-mailing them, (yet!), just to stop with the "grenades".

Yes, that very word came from one of the authors: JRG

and metamars, who I am sure can speak here, for himself, has been asked by Kevin Ryan to remove him (Kevin) from his (metamars) email list.

Metamars:

Have you been requested by anybody other than Kevin Ryan? (He also asked me to remove him from my "email list", so I stopped cc'ing him.)

All quotes above, from:

http://the911forum.freeforums.org/active-thermitic-material-in-wtc-dust-t150-60.html

The reason I post these, outside of the obvious curiosity, is to point out, in yet another way, the lack of professional approach these scientists have. Any scientist, any real scientist, will tell you that analysis and criticism of scientific work, yes even there own, is what science is all about. It is part of what purifies the field, so to speak. Repeatability, explaining in or out other possibilities, etc...are all part of this, but also seem to be parts these particular scientists dislike...very much.

TAM

 

[Sunstealer]

The machine in your link isn't a sputter coater, it's a small benchtop evaporator for gold-coating SEM samples. A decent sized sputter coater is much, much bigger.

Dave

They are always called sputter coaters in the industry. eg:

http://www.emitech.co.uk/pdfs/sputter_coating.pdf

I know it's a bit off-topic but what's the larger machine?

 

[ElMondoHummus]

I want to reply to a couple of comments that metamars made in the closed thread on Jones's Bentham paper, and I think this is probably the appropriate place to do it. I was away over Easter, so it took a while to catch up, but the specific post is at http://www.internationalskeptics.com/forums/showthread.php?postid=4599311#post4599311.

First of all, I think this may have been covered, but I'd like to put it to bed:



No, I have it the right way round. The Wikipedia article on energy density (http://en.wikipedia.org/wiki/Energy_density) explains it similarly:


Therefore thermite, which holds its own oxidiser, has a lower energy density, at around 4kJ/g, than combustible materials that don't contain their own oxidisers, for example kerosene at around 43kJ/g.

Now the rather more complex point:




Let's take a look at the figure in question, reproduced here under fair use conditions as a small part of the above referenced work for research.

[URL]http://www.internationalskeptics.com/forums/imagehosting/1476449e7178ebe28d.bmp[/URL]

It's not entirely clear, but look at the Y axis. The highest value quoted is less than 4000J/g, the figure for the energy density of thermite.

Now, let's address the comment "Apparently you're thinking of perfect reactions". I'm using the term "energy density", which is perfectly clear, and is equal to the amount of energy that can be released in a 100% efficient reaction. What we can see from Grainier's thesis is that the amount of energy released by any thermite formulation is less than its energy density, but that the efficiency of energy release is greater for smaller particle sizes. This is completely consistent with the fact that the energy density of thermite is independent of particle size, as I originally pointed out.

Now, going back to the paper, DSC results indicate energy releases of 1.5, 3, 6 and 7.5kJ/g from four samples, with the comment made that the underlying grey layer is included in the mass but does not react, so does not contribute to the heating. We can assume, therefore, that the minimum possible value of energy density of the material believed to be thermite is 7.5kJ/g, or nearly twice the energy density of pure thermite. This is assuming a perfect reaction, and assuming that there is no inert grey layer on the sample giving the highest energy release; if either of these assumptions is invalid, then the actual energy density must be greater. The conclusion is simple and inescapable: the material is not thermite...

Dave

To the best of my knowledge, this is absolutely correct.

Dave, just as a little addendum: I've been trying to reeducate myself on the chemistry concepts I've let lay dormant for a heckuva long time now. I think the relevant stuff to look up here in order to really understand how Jones was fooling everyone - and how the paper Metamars is citing applies - is to study the concept of "enthalpies of reaction". The enthalpy of a perfectly stoichiometric and fully complete thermite redox is well known. The paper Metamars cites does discuss how changes in particle size help 1. Speed of reaction (which is something we all already knew) and 2. Completeness of reaction (which speaks to real world, not idealized everything-reacts-100% situations). Because decreasing the particle size helps aid a reaction get closer to a perfectly stoichiometric balance, it does indeed release more energy per gram. However, your, my, and other's points are still entirely valid: You canNOT exceed the enthalpy of a perfect reaction. You simply can NOT. The energy is not there to begin with. So the point here is that people have to draw distinctions between understanding how particle refinement releases energy by allowing for a more complete reaction, and how the ultimate limit is not dictated by the particle size, but by the chemical bond energy that's available to begin with. Refinement can increase energy released, but only up to that limit. Exceed the limit, and you know that you're no longer talking about a ferrous-oxide/aluminum redox reaction.

That may be obvious to those of use who've taken enough chemistry courses in college to understand this without needing it to be explicitly pointed out, but I have to allow for the fact that well-meaning readers might not have thought of this. So please forgive the pedanticism, but I felt that this must be said. Even if it's obvious to you, others might find it useful to know.

 

[metamars]

"traditional thermites" vs. HMX, RDX, TNT

I have quantified differences graphed in Grainier's Figure 1 (by counting pixels).

In terms of energy / volume,

HMX is 52% Al/Fe2O3
RDX is 52% of Al/Fe2O3
TNT is 29% of Al/Fe2O3


In terms of energy / mass

HMX is 24% Al/Fe2O3
RDX is 22% of Al/Fe2O3
TNT is 12% of Al/Fe2O3

 

[metamars]

Blast! (pun intended)

My previous post I referred to the Grainier thesis. It was actually the Andrew Francis thesis, MODELING THE MELT DISPERSION MECHANISM FOR NANOPARTICLE COMBUSTION

 

[alienentity]

I wasn't thinking of sputter coating steel columns.....etc..

I suspect you would only need sputter coating for precise control of thickness and geometry, while depositing Al by vaporizing it first (assuming this would even work) would give more uneven results.

metamars, aren't you getting WAY ahead of the evidence here? Right now what the thermite theorists have is a few tiny chips of a 'suspect' material.

It has not been established by the scientific community whether these are in fact thermite or not; and as Dave has pointed out, some of the samples should be eliminated based on their energy densities.

I suggest that you might focus your inquiries on said chips and how the Jones paper results might be validated.

I hope you will forgive us skeptics for discouraging such speculation, but you must remember that you are, in no uncertain terms, accusing your government of performing this hypothetical act of mass murder - the burden of proof needs to be very high indeed.
In all fairness the 9/11 'truth' movement, which I gather includes you, is accepting a fairly LOW BOP, which is extremely offensive to many of us.

Rather than BEGINNING your inquiry with an open mind, and simply assessing evidence, the assumption you're starting with is 'THEY did it, with thermite, but how?' All three of those assumptions are intellectual traps you MUST avoid.

Can you really blame the NIST investigation for NOT pursuing the CD scenario given the paucity of evidence which leads there? Perhaps in a few more years you will perceive the gravity of the errors that your movement is making, the harm and pain it is causing, and, perhaps more important, the great patience, caring and wisdom of many of the skeptics on this forum who are responding to you with civility.

I hope that day comes for you. In the meantime try to say focused on the issue at hand: the red chips. Be prepared for failure.

 

[Lenbrazil]

Very, very interesting admission by Jones et al upon questioning via email by Dr. Greening...



//the911forum.freeforums.org/active-thermitic-material-in-wtc-dust-t150-30.html

Yes you read it correctly, Jones seems to be back tracking, CONSIDERABLY, to declare that the last several years of thermite talk, has been for Explosive "FUSES"!!!!

I am speechless.

TAM

They said this in the paper (PGS 20 – 23) - [Emphasis in original text]

“Super-thermite electric matches” have been developed at Los Alamos National Laboratory for which “applications include triggering explosives for ... demolition” [30]. It is indeed possible that such matches, which are designed to be ignited by a simple electric pulse, could contain material… similar to the red material we have found in the WTC dust. With regard to the safety of super-thermite matches, the Los Alamos announcement notes:

“Unfortunately, conventional electric matches
use lead containing compounds that are extremely
sensitive to impact, friction, static, and
heat stimuli, thereby making them dangerous to
handle. In addition, these compounds produce
toxic smoke. The Super-Thermite electric
matches produce no toxic lead smoke and are
safer to use because they resist friction, impact,
heat, and static discharge through the
composition, thereby minimizing accidental ignition…”​

[…]

It may be that this material is used not as a cutter-charge itself, but rather as a means to ignite high explosives, as in super-thermite matches [30].

But then if the red material were part of some sort of fuse mechanism all the stuff about how high its energy content is basically irrelevant (or so it seems to a layman like me).

They also contradicted themselves they emphasized the excerpt of the “Los Alamos announcement notes” about how thermite matches resist heat - which conforms w/ Jones observation in his 1st “paper” that thermite, unlike RDX etc. only ignites at temps well over 1000* C – but earlier in the new paper noted that “the material ignites and reacts vigorously at a temperature of approximately 430 °C.”

They fail to explain why a substance that “ignites and reacts vigorously” at temps commonly seen in office fire would have been used. Just how would one control the demolition under such circumstances? If it were painted on cutter charges instead of steel I imagine it would have heated that much more quickly because the wicking effect the steel frame would not come into play.

My guess is that either they had the paper mostly written when they did calcs like Ryan Mackey’s and Greening’s and realized that there wasn’t nearly enough of the material to do any damage to the towers either as an explosive or heat source and quickly added the stuff about “super-thermite matches” and/or Harrit and Jones wrote those parts separate and failed to notice the contradiction or hoped no one else would notice when they cobbled it together.

 

[metamars]

The reason I post these, outside of the obvious curiosity, is to point out, in yet another way, the lack of professional approach these scientists have. Any scientist, any real scientist, will tell you that analysis and criticism of scientific work, yes even there own, is what science is all about. It is part of what purifies the field, so to speak. Repeatability, explaining in or out other possibilities, etc...are all part of this, but also seem to be parts these particular scientists dislike...very much.

TAM

While I regret that many of Dr. Greening's criticisms and helpful suggestions are not better received, I have been cc'd on some of the emails, and I understand that some of the scientists are a bit peeved over past events. It doesn't help that some of them conflate Dr. Greening with JREF - even if they're aware of a 'split', let's call it. I certainly am sympathetic to some of their frustrations, not least of which is, having to work pro bono, they cannot devote the time and resources following every suggested method that has been put to them.

I suggest you suppress your tendency to always make 911 Truth sympathizers look bad, at least in this case, as you are not privy to these emails. And no, I'm not going to ask for permission to print them on a public forum.

If you're honest, you must admit that they have put their careers and reputations on the line. The tone of some of those emails make it obvious that they are quite confident of what they have found. However, it remains to be seen what the scientific community makes of their claims, and what their own future research will show. E.g., Professor Jones was quite enthused about a reference I gave him for a technique which is cheap and "quasi" non-destructive, that should be able to identify the chips as paint or some sort of coating, if they are indeed, such. As Professor Jones has already given me permission to publish his emails, I will quote his reply:

I find this to be a wonderful suggestion and I would like to have the
LIBS testing done. ........

Thanks for bringing this to our attention.

Steven J

This was in reply to my email:

Subject: easy, virtually non-destructive way to test chip sample, to compare with LIBS spectral fingerprinting of paints and coatings

Please see the following. I strongly urge you to do such testing, which looks to me like it would greatly reduce any uncertainty about whether or not the chips could be any known painting or coating.

<name redacted>



See http://www.springerlink.com/content/r19145r8870qr41t/


Taesam Kim1, Binh T. Nguyen2, Vari Minassian2 and Chhiu-Tsu Lin1
(1) Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
(2) Caterpillar Inc., Technical Center, Bldg. K, 14009 Old Galena Road, Mossville, IL 61552, USA
Published online: 20 June 2007

Abstract Two algorithms—peak picking and peaks correlation—have been compiled in a portable laser-induced breakdown spectroscopy (LIBS) system and used specifically for spectral fingerprinting of paints and coatings, which contain multiple ingredients and require several application steps. The LIBS technique starts with a laser shot on the specimen surface, detection of the emission of the elements present, and analysis of the sample compositions. The LIBS system has been successfully illustrated for the identification and analysis of coating substrates, surface pretreatments, and primer and topcoat paints obtained in the lab and at field sites. The results indicate that, despite the compositional complexity in organic metal finishing, the spectral fingerprint of paints and coatings can be effectively determined by the LIBS technique. The advantages of LIBS technique over other conventional methods, such as EDX, are that it is quasi-nondestructive (<100 ?m of sample size), requires no sample preparation, is fast (within minutes), is user-friendly (for nontechnical personnel), and is capable of application both online and at the field sites.

Besides the fact that my suggestion had the nice benefit of likely being affordable, I put it politely. This is not to say that serious suggestions and criticisms should be ignored if they're rudely put, just that these particular scientists are not as closed off to criticisms and suggestions as you might think they are.

Finally, I got a reply from one of the scientists (not Jones) who had wanted to use a technique closely related to LIBS, and had suggested so much twice, but was waiting for a "60 hour day" to do it (presumably on his own).

 

[beachnut]

I have quantified differences graphed in Grainier's Figure 1 (by counting pixels).

In terms of energy / volume,

HMX is 52% Al/Fe2O3
RDX is 52% of Al/Fe2O3
TNT is 29% of Al/Fe2O3


In terms of energy / mass

HMX is 24% Al/Fe2O3
RDX is 22% of Al/Fe2O3
TNT is 12% of Al/Fe2O3

TNT is 31.67 percent Fe2O3 + 2Al

Are you numbers correct? What was the source?

chocolate chip cookies are 426 percent Fe2O3 + 2Al

It was the cookie crumbs Jones should be looking for.

 

[Dave Rogers]

They are always called sputter coaters in the industry. eg:

http://www.emitech.co.uk/pdfs/sputter_coating.pdf

Sorry about that, you're right, it is a sputter coater. There's not that much difference between them and small evaporators.

I know it's a bit off-topic but what's the larger machine?

Similar, but production scale, with multiple targets and 4" wafer capability (might take 6" at a stretch). Evaporators seem to scale better than sputter coaters, so a similar sized evaporator won't be anything near as big.

Dave

 

[metamars]

No, I have it the right way round. The Wikipedia article on energy density (http://en.wikipedia.org/wiki/Energy_density) explains it similarly:

OK, gotcha.

Therefore thermite, which holds its own oxidiser, has a lower energy density, at around 4kJ/g, than combustible materials that don't contain their own oxidisers, for example kerosene at around 43kJ/g.

Now, here I'm confused. Even given the correct, wikipedia definition of energy density, the Francis Andrew thesis shows a AlFe2O3 energy density of 4,000 cal/ gram (in Figure 1). But 4,000 calories is not 4 J, but rather 16,736 J, according to this converter. (Also, this converter.) So, it looks to me like the wikipedia entry is wrong.

Although I know neither Mr. Wikipedia nor Mr. Francis, I think that it's most likely that I, wikipedia, and then Francis have made a mistake - in that order.

With 16 KJ/g energy density (I still have to force myself to use the phrase correctly ), it's simply not true that chips which weigh in at 8 KJ/g have " nearly twice the energy density of pure thermite." Rather, their effective energy yield is about half of thermite's energy density.

 

[metamars]

[qimg]http://www.internationalskeptics.com/forums/imagehosting/1476449e7178ebe28d.bmp[/qimg]

It's not entirely clear, but look at the Y axis. The highest value quoted is less than 4000J/g, the figure for the energy density of thermite.

What is probably a minor point: that graph is for Al/MoO3. It's probably minor, since Al/MoO3 has about a 7% higher energy density than Al/Fe2O3 (determined by eyeballing Fig 1 in the Andrew Francis thesis.)

Clearly, the chips in Jones, et. al., if they are thermites, at all, are not composed of spherical nano-particles of Al, which is the only sort of Al particles hitherto known to myself (and, I suspect, to the scientists working on nano aluminothermics, in general). It's certainly the type of Al particles studies by Grainier.

I have speculated that the whole point of a platelet morphology is to allow both a higher effective energy ("practical energy density", if you will), as well as lower power (i.e., slowing down the reaction). While I have presented arguments to support my speculation, I don't stand by them as anything other than speculation, and hope that capable scientists will weigh in with at least their theoretical opinions, even if experimental confirmation, in the public domain, of this idea is a long way off.

I'm sure we all agree, though, that if there is a way to double and treble the effective energy content of nanothermite, that is highly desirable from a CD and weapons point of view.