An analysis of the DSC data in the Herrit-Jones paper

Originally posted by pteridineTurbofan, please stay focussed. We are discussing Jones' data, not the operation of the DSC. Heat flux is determined by relative temperatures. What is the point of your question?

You need to understand how a DSC functions and how to read the trace. Your recent comments prove
otherwise.

In order to continue to discussion, you must clarify whether you believe heat can be transferred back into
the test platen during a reaction.

By doing so, we can begin to analyse the trace and compare Tillotsons control sample against Jones'
analysis.

Here is a copy of Tillotson's chart directly from his paper. I hope you have read it; right now it appears neither
you or PLB have!
[atsimg]http://files.abovetopsecret.com/images/member/b71532097af4.jpg[/atsimg]

Pteridine,

Do you agree that heat can be transferred back into the test platen during a reaction.

Yes, or no?

reply to post by turbofan


Turbofan,
What is your point? Do you want to discuss Jones data or not? Tillotson made the material. He knew what he had. Jones had an unknown sample.

Do you concede that Jones has to run the DSC under argon before he can claim thermite and you now want to move on?

State your complete argument. I may even agree with you.

reply to post by pteridine


I've already stated my point. It is obvious you don't understand it. It is also obvious you have not read the
LLNL documentation, nor do you understand how to interpret the trace.

We will discuss Jones' data once we correct and clarify your assumptions in the opening post of your thread.

Once we agree and clarify your points we can move forward.

Until then you have not shown you understand the concepts and therefore can not possibly and successfully
critisize Harrit and Jones.

The concept is quite simple Pteridine. Heat IS MOST DEFINITELY transferred back into the test platen during
a reaction. That is how a DSC machine produces the trace which we view on the graph.

Therefore since HEAT IS MOST DEFINITELY transferred back into the test plate, we can compare the energy
release of materials and how explosive they are (narrow vs. wide trace), how much heat is produced (peak of the
trace), and their change of phase (reaction temperatures indicated by start of the exotherm) to name a few.

Do you agree with these points?

Finally, please supply the link to the LLNL document to prove that you are comparing the procedure that Jones
used with the procdure used by Tillotson.

reply to post by turbofan


Jones' excuse for running it in air was that Tillotson did it. The reference is Ref 28 in the paper.

No matter how you spin this, Jones' team erred by running this in air and Jones knows it.

He was trying to show a reaction that didn't need air in the presence of a combustion. He can't deconvolute the data from this experiment to determine what was combustion and what was something else. His position is not defensible. What he is doing now is trying to change the subject to anything but his own data and the fact that the chips didn't even completely react.

You might want to look at the specifics of the Netzsch 404C before we get too far into this.

S&F pteridine for your post. Ahh, my days in the laboratory...

It is odd that they did not run the samples under an argon cover, but that may not be the biggest problem here. I would argue that DSC type calorimetry is very difficult to reproduce and may be a poor method to determine if the "paint" is thermite, thermate, etc. They most certainly would need to verify samples of known masses and heat contents to verify the instrument and method of analysis.

DSC suffers for this type of analysis due to:
1) The heating rate is too slow and does not reflect a high heat input source that is typically used to react thermite/thermate
2) The samples sizes are too small and allow for large error in small sample mass changes during the sample run
3) The response time of the thermocouple is too slow to account for the temperature changes involved in thermite/thermate reactions

Didn't the report show SEM images of aluminum oxide microspheres?

Originally posted by pteridine
reply to post by turbofan

 

Jones' excuse for running it in air was that Tillotson did it. The reference is Ref 28 in the paper.

No matter how you spin this, Jones' team erred by running this in air and Jones knows it.

You are wrong and we will prove it shortly.

Is it safe to say you have not read the LLNL paper since you have not produced the link?

He was trying to show a reaction that didn't need air in the presence of a combustion. He can't deconvolute the data from this experiment to determine what was combustion and what was something else.

THis is where we will expose your lack of scientific understanding.

Not only have you avoided my questions about heat transfer, you are admitting that you have not read the LLNL
experiment summary.

We will now begin to expose your errors and claims that:

1. The term "Thermitic" was invented by Jones to describe a type of thermite

2. You cannot discern between a combustion event and an explosive event using a DSC trace

3. Iron-rich, or "iron containing" with respect to spheres discounts the discovery of an energetic thermitic material

Further to those points, we will prove that you have unsuccessfully critiqued the Harrit/Jones paper by comparing
the results from LLNL with the WTC Dust analysis.

First off, Pteridine:

Do you agree that you lied and fabricated the rumour that Jones created the term "thermitic"?

reply to post by turbofan


Turbo, what is Jones' paper called?

"Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe"

So no, pteridine didnt lie.

reply to post by GenRadek


Please do not answer questions that are not directed to you.

Your answer doesn't even cover my question. Just because Jones used "Thermitic" in his title, does NOT
mean he created the term.

Pteridine constantly states that "Jones claimed thermite" based on the term thermitic. I will give him a chance
to own up to his error, and then show you a use of this term that predates Jones' paper by at least 5 years.
I will also show it's reference is universal, and it Tillotsons case refers to nano-energetics.

reply to post by turbofan

Your attempt to play the prosecutor is most humorous. We are discussing Jones data, not his use of a term. I don't care who invented it and never have. Jones says the components of thermite are in the paint chips. That is his theory. He then tries to prove it and doesn't.

Now, he is trying to do damage control by proxy while he tours the lecture circuit.

It's not funny at all; unfortunately this is a point that must be cleared so that you stop propagating your stirring of
Jones' words around the internet. That is the purpose of this debate: to find errors in your summary and correct
them.

Then you agree that Jones did not invent the term, "thermitic" and that Jones concludes the finding of nano-energetic material in his paper.

Can we move onto the next point?

reply to post by turbofan


Why don't you just stop dancing around the bush and tell us how the energy readings are much higher than possible in a thermite reaction?

Originally posted by turbofan
reply to post by -PLB-

 

That is how science works. You don't alter a known procedure and expect to compare similar data

Ownage....that should be the title of this thread. It's rare to see such a technical debate on ATS, and especially in this forum. Cheers to those geeks involved...but one team here is going to need a miracle.

reply to post by turbofan


I don't agree that I "lied" about anything as you suggested previously. You are mistaken. I agree that Jones claimed nano-particulate thermite in a matrix of energetic material.

Now please explain the excess energy and how Jones can show what fraction of the energy came from any thermite and what fraction came from combustion.

Originally posted by pteridineI don't agree that I "lied" about anything as you suggested previously. You are mistaken. I agree that Jones claimed nano-particulate thermite in a matrix of energetic material.

Well, that's a start. The paper concludes specifically:

Based on these observations, we conclude that the red layer of the red/gray chips we have discovered
in the WTC dust is active, unreacted thermitic material, incorporating nanotechnology, and is a highly energetic
pyrotechnic or explosive material.

This is further supported by Jones' recent e-mail response:

The term nano-thermite may be a source of confusion. More accurately, the red layer is a thermitic nano-composite.

The term "thermitic" has been used in science by scientists long before the release of Jone's paper. Here is at
least one (of several that I have found) dating back to April, 2000:

Page 11, of "Making Nanostructured Pyrotechnics in a Beaker."
inspire.ornl.gov...

Dilution of the thermitic material with inert oxides such as Al203 (from
dissolved AlC13 salt) or Si02 (from added silicon alkoxide) leads to a pyrotechnic
material that is not as energetic as a pure iron(III)-oxide-aluminum mixture.

Now please explain the excess energy and how Jones can show what fraction of the energy came from any thermite and what fraction came from combustion.

We'll be onto this dicussion shortly, but first we must agree on how to interpret the DSC trace as it will
be part of the criteria used to distinguish between a combustion event, and an 'explosive' event.

Pteridine, do you agree that a more narrow exotherm indicates a reaction which is closer to that of an explosive
rather than combustion?

Do you also agree that a sharp slope (positive , or negative) indicates the speed of a reaction closer to that of
an explosive rather than combustion?

In the figure below (From Tillotson's paper), the scientists conclude that thermitic reaction begins at 500'C,
and the exotherm centers at the 530'C point along the x-axis. Even though there is presence of heat over the
control temperature at 400'C through 500'C, this section is excluded as the 'active' region

One can see that the DSC is essentially featureless at temperatures below 500'C. Above that
temperature is a large exothermic peak which dominates the trace.

[atsimg]http://files.abovetopsecret.com/images/member/b71532097af4.jpg[/atsimg]


Finally, do you conclude that the quick drop, and slope of the exotherm indicates that the available energy
was spent in quick fashion and more closely resembles an explosive event, over a combustion event?

Originally posted by turbofan
Pteridine, do you agree that a more narrow exotherm indicates a reaction which is closer to that of an explosive
rather than combustion?

Do you also agree that a sharp slope (positive , or negative) indicates the speed of a reaction closer to that of
an explosive rather than combustion?

Although I am no expert so I can be wrong, but no, I do not agree with your statements. The graph shows the energy release with relation to temperature. The sharpness of the slope depends on how much material will combust or react at a certain temperature, and on how fast the temperature changes. For example, the peak in the figure you posted spans from 420 to 460. That is an increase of 40 degrees, so at 10 degrees/min that is 4 minutes. 4 minutes is more than enough time for some combustion to take place.

A quick google search showed me that the DSC of combustion of asphaltites, coal and crude oil show similar peaks. Just type "dsc combustion" in google, and open the PDF's on the first page, for example etd.lib.metu.edu.tr... page 62.

So unless you can substantiate your claims, you seem to be wrong. The DSC's I found of combustion show similar shapes.


Anyway, all this seems to be distration from the main point, which is where does the excess energy come from. A thermite reaction has a maximal energy density of 3.9MJ/g and the measured energy density in one case was 7.5kJ/g. So there is an excess of 7.5 - 3.9 = 3.6kJ/g. From what reaction exactly does that come from? It is not a thermite reaction.

Originally posted by -PLB-
Although I am no expert so I can be wrong,

Pteridine and I will discuss energy once we're on the same page about reading DSC curves. There's no
point moving forward if we cannot faithfully agree on what the trace indicates.

Your comparison falls short unfortunately. The graph you are comparing has a horizontal scale measured
in Kelvin. You must first transpose the graph to be scaled at Celsius.

Second, you must also compare the trace which is ramped at the same control rate of 10'C/minute.

Lastly, the veritcal scale is mW increments. Tillotsons scale is Watts. 1000 mW = 1 Watt.

Neither of the curves you compare exhibit a sharp slope; certainly not the red trace [10'C/minute]

If you take the time to redraw those curves on a Celsius scale @ 10'C/minute, they will look nothing like
the traces in Tillotson, or Jones' paper...they don't even look close now.

P.S. YOu are not disagreeing with me, you are disagreeing with the scientists and Lawreance Livermore National
Labs.
The quote and graph you are viewing are from the Xerogel study by Tillotson and various authors.

Originally posted by turbofan
Pteridine and I will discuss energy once we're on the same page about reading DSC curves.

Your comparison falls short unfortunately. The graph you are comparing has a horizontal scale measured
in Kelvin. You must first transpose the graph to be scaled at Celsius.

I have to say my jaw kinda dropped from this statement. Do you have any technical education at all? Anyone with just the slightest technical education knows that Kelvin and Celcius have exactly the same magnitude. The only difference is an offset.

Second, you must also compare the trace which is ramped at the same control rate of 10'C/minute.

You also need to learn how to read graphs. When you scale the 10C/min graph to full height, you get a similar spike again. Similarly, when you scale the graph you posted on page 1 to a lower height you get a less steep curve.

Lastly, the veritcal scale is mW increments. Tillotsons scale is Watts. 1000 mW = 1 Watt.

Neither of the curves you compare exhibit a sharp slope; certainly not the red trace [10'C/minute]

If you take the time to redraw those curves on a Celsius scale @ 10'C/minute, they will look nothing like
the traces in Tillotson, or Jones' paper...they don't even look close now.

edit on 6-12-2010 by turbofan because: Watt scale.

The units have nothing to do with relative change, only with absolute change. This also holds for your temperature argument. One graph is in mW, the other in W/gram. To transfer mW to W/g, all you need to is devide the value by the weight of the tested material. The shape of the curve does not change whatsoever.

I think this will be my last reply, as you have shown you have no technical background at all, and you have no clue of how to read a graph. I don't see this going anywhere anytime soon.

Originally posted by -PLB-

Originally posted by turbofan
Pteridine and I will discuss energy once we're on the same page about reading DSC curves.

Your comparison falls short unfortunately. The graph you are comparing has a horizontal scale measured
in Kelvin. You must first transpose the graph to be scaled at Celsius.

I have to say my jaw kinda dropped from this statement. Do you have any technical education at all? Anyone with just the slightest technical education knows that Kelvin and Celcius have exactly the same magnitude. The only difference is an offset.

Meaning of transpose: to transfer or shift

ref. YourDictionary.com

In otherwords, you must redraw the exotherm trace on a Celsius scale.

600 kelvin = 326.85 degrees Celsius

How does that line up with the exotherm of Tillotson's graph PLB?

Second, you must also compare the trace which is ramped at the same control rate of 10'C/minute.

You also need to learn how to read graphs. When you scale the 10C/min graph to full height, you get a similar spike again. Similarly, when you scale the graph you posted on page 1 to a lower height you get a less steep curve.

What does height have to do with the X-axis PLB? The X-axis is horizontal, left to right.

Lastly, the veritcal scale is mW increments. Tillotsons scale is Watts. 1000 mW = 1 Watt.

Neither of the curves you compare exhibit a sharp slope; certainly not the red trace [10'C/minute]

If you take the time to redraw those curves on a Celsius scale @ 10'C/minute, they will look nothing like
the traces in Tillotson, or Jones' paper...they don't even look close now.

edit on 6-12-2010 by turbofan because: Watt scale.

The units have nothing to do with relative change, only with absolute change. This also holds for your temperature argument. One graph is in mW, the other in W/gram. To transfer mW to W/g, all you need to is devide the value by the weight of the tested material. The shape of the curve does not change whatsoever.

Really? So if I were to redraw both curves on a Celsius scale @ 10'C/minute, with mW/g and W/g converted on the Y axis,
the shape of the curve wont change with respect to the original graph?



How much lunch money would you like to bet? I'll take the time to redraw this at some point. Until then, I'll wait
for someone else to agree with you. I wont hold my breath...

Maybe you meant the SLOPE of the curve ... perhaps? This of course if a linear realtionship holds true.

I think this will be my last reply, as you have shown you have no technical background at all, and you have no clue of how to read a graph. I don't see this going anywhere anytime soon.

Fine by me. I'd rather discuss this with Pteridine as he seems more educated on this topic. Don't worry Pteridine,
I wont hold any of these other replies from your 'supporters' against you.

Originally posted by turbofan
Really?

Yes, really. Scaling of the X and Y axis is unit independent. You can interchange the units and values without making any modification to the curves, as long as the scale remains linear. This is fundamental basic knowledge, its just not funny anymore.

Originally posted by -PLB-

Originally posted by turbofan
Really?

Yes, really. Scaling of the X and Y axis is unit independent. You can interchange the units and values without making any modification to the curves, as long as the scale remains linear. This is fundamental basic knowledge, its just not funny anymore.

edit on 6-12-2010 by -PLB- because: added bit of info

Just wanted to quote this for when I post the re-draw. Maybe I'll mail this and the graphs to your grade-school
teachers too.