Crackle research

richardh08 · Post by **richardh08** » Sun Oct 07, 2018 10:07 am

After nearly four years of playing with a wide assortment of crackle formulations, I believe I have finally started to make progress in understanding exactly how it works.

About ten days ago I submitted a paper to Propellants, Explosives, Pyrotechnics (PEP) describing my initial findings in relation to a particularly simple composition. It's only a first step, but I believe it to be a crucial one that provides a baseline for the study of more complex formulations.

Two people have independently told me that, compared with other journals, PEP is particularly slow at processing submissions, so it may be a long wait to find out whether or not the paper will be accepted for publication. However, my submission's status has recently changed from 'Received' to 'Under review'. Let's see if it passes this first hurdle.

Post by **Lloyd** » Sun Oct 07, 2018 11:49 am

Congratulations on both points, Richard. I think I'd be more-tickled of the first than the second! Four years of "sticking to it" speaks well of your tenacity!

Lloyd

richardh08 · Post by **richardh08** » Fri Oct 19, 2018 2:45 pm

My submission has remained 'Under Review' for two weeks now, with no sign of anything happening.
I suppose the good news is that it hasn't been summarily rejected. Alternatively, it could just be at the bottom of a large pile in someone's in-tray. Oh well, they say patience is a virtue.

In the meantime, I'm spending significant amounts of time staring at (graphs of) the large collection of numbers that have accumulated from my tests on a variety of compositions, trying to find different ways of extracting meaning from the results. So far, I've found one or two new, interesting relationships but I don't yet know if they are going to help me understand what is going on.

sambo · Post by **sambo** » Fri Oct 19, 2018 7:38 pm

In my experience Richard, although your journals may be different, it takes months, then more months when they ask you to make changes and resubmit. Then even more months before it's scheduled for a particular journal. I think in one instance it was coming on for 18months

richardh08 · Post by **richardh08** » Sat Oct 20, 2018 10:03 am

That is sooo not what I wanted to hear, Sam

Looking at a few sample papers tells me that the delay from submission to publication in PEP tends to be anything from three to five months. Not all papers needed revisions but of those that did, there don't appear to be any examples where the time from first submission to a revised version is less than about three months.

Realistically, I can't see anything happening this side of Christmas.

sambo · Post by **sambo** » Sat Oct 20, 2018 8:30 pm

Sorry Richard. I think you are right

It will be worth the wait and we're all rooting for you !

richardh08 · Post by **richardh08** » Fri Oct 26, 2018 8:59 pm

As a break from staring at loads of numbers, I’ve been doing a bit of reading, brushing up a bit on my 50-odd year out-of-date knowledge of astronomy and physics. As a result, I realize that what I’m doing now is remarkably similar to what I was doing all those years ago when I was trying (and ultimately failing!) to make my way in astronomical research. A quote from one of the books I’ve just read:

”Discovery is frequently complicated (in astronomy) by a lack of the complete and rigorous information that is typically present in other sciences … we must accept the few bits of data (that) nature throws our way.”

Attempting to determine the chemistry of crackle compositions from not much more than a series of temperature records feels a bit like that.

Post by **Lloyd** » Fri Oct 26, 2018 9:45 pm

Man! Richard, I feel for you. I've approached (and a few times succeeded on) some "impossible missions", where there was just not-enough information to proceed.

But they're rare in success, and very-rewarding when you battle past the obstacles.

Lloyd

richardh08 · Post by **richardh08** » Sun Nov 18, 2018 1:04 pm

I see that the status of my submitted paper has, at some time in the last few days, changed from 'Under Review' to 'Evaluating Review' (whatever that means).

richardh08 · Post by **richardh08** » Mon Nov 19, 2018 10:12 am

This morning, the status is back to 'Under Review'. Ho-hum.

richardh08 · Post by **richardh08** » Tue Nov 20, 2018 11:39 am

... and now back to 'Evaluating Review' ... ???

Post by **Lloyd** » Tue Nov 20, 2018 12:47 pm

The editor-in-chief doesn't do all the reviews, but 'reviews the reviews' for language, continuity, etc. He/she didn't like something about some part of it, and sent it back for correction.

Lloyd

richardh08 · Post by **richardh08** » Tue Nov 20, 2018 1:03 pm

It must be something like that, Lloyd. Or perhaps there are two or more reviewers, whose comments came back at different times.

richardh08 · Post by **richardh08** » Thu Nov 22, 2018 11:33 am

The status has now been 'Evaluating Review' for several days. Also, I've just noticed that a second editor has been allocated, with a designation of 'EE' (the first editor has 'EO' but I don't know what either of these abbreviations mean).

I take this to be an encouraging sign that a) someone has reviewed the article and b) the review was sufficiently encouraging to bring in a second (more senior?) member of the editing team.

richardh08 · Post by **richardh08** » Fri Dec 07, 2018 10:51 pm

Earlier this evening I received an email from PEP informing me that my paper would be accepted for publication, subject to some revisions in line with comments by the reviewers. Many of the reviewers' points make sense, but one or two do not and others, while outwardly reasonable, suggest modifications that are not practical. I suspect that I may have to haggle, in the hopes that we can reach a reasonable compromise.

Post by **Lloyd** » Sat Dec 08, 2018 12:06 am

Richard,
It's unlikely that they understand crackle as do you, nor have they done all the research into it you have (or, for that matter... ANY!).

STICK TO YOUR GUNS! (That may be an American expression). You need to IMPOSE on them the facts, rather than their opinions not based in fact.

Yours,
Lloyd

richardh08 · Post by **richardh08** » Sat Dec 08, 2018 12:28 am

I'm happy to stick to my guns (which is also a well-known expression in the UK, even if most of us don't have any) on key issues. One of the two reviews was entirely reasonable, suggesting only a few changes to clarify one or two points, and I'm perfectly happy to implement almost all of them. The second was more wide-ranging and raised more criticisms. However, it seems clear to me that the author is not taking into account the pyrotechnic origin of the data, which means that you can't expect the kind of precision that comes from more closely controlled experiments. My options are either to do a total rewrite or to ignore almost everything in that second review and explain in a covering note why I have done so. I will surprise myself if I end up doing anything other than take the second of these two options.

Post by **Lloyd** » Sat Dec 08, 2018 12:41 am

Good for you, Richard.

DO "stick to your guns".

The research you've done is invaluable to the art, and far-beyond anything those 'editors' even understand.

Lloyd

richardh08 · Post by **richardh08** » Sat Dec 08, 2018 3:43 pm

Having slept on it, the excitement has died down a little. A slightly more rational look at the reviews reveals that both of them make a number of points that are worth considering. In fact, the second one is a lot less critical than I first thought. I've put a couple of the issues it raises together with one or two somewhat puzzling things I've discovered since writing the first draft. It all makes a lot more sense now. I'm definitely going to have to make some alterations, including revealing a few more of the 'warts' in my data and how it is interpreted. But I don't think it will significantly change the main drift of the article.

dave321 · Post by **dave321** » Sun Dec 09, 2018 12:05 am

hope you will be able to supply us a copy when it is published, its certainly being a great body of work to read through,
and conrgats on its future publication(hopefully)

i think i read somewhere that one of the problems from a researchers point of view, and i am thinking of the usual type of
academic research performed in universities / institutions etc is that ultimately, it is the publishers that effectively get all the monetary rewards, for what is basically somebody else's work, by charging for each published article /journal subscription.

i guess sadly this publishing model will never change.

richardh08 · Post by **richardh08** » Sun Dec 09, 2018 10:21 am

PEP - as, I suspect is the case with all other journals - is very protective of its copyright on articles it publishes. I haven't gone into the details of what I will be able to publish and/or distribute but it is clear that my options will be limited and I certainly won't be allowed to put a full copy on any public forum. But since it contains a lot of 'guff' about how the findings relate to other research into thermites, that might be a good thing!

I suppose they have to make their money some way or other, but I was somewhat upset to learn that they would ask me to pay for any colour printing (fortunately, there isn't any). They are also likely to ask me to pay for the publication of any seventh or subsequent page. According to my adviser, that isn't uncommon. He says I have the perfect defence, in that my research receives no external funding, but we'll have to see how that pans out.

richardh08 · Post by **richardh08** » Sat Dec 15, 2018 1:49 pm

I submitted the revised manuscript yesterday.

richardh08 · Post by **richardh08** » Fri Dec 28, 2018 1:43 pm

The resubmitted manuscript's status is still "Evaluating Review". Given the time of year, I expect to have to wait a while longer for a response.

In the meantime, I've been thinking about how I could improve the experimental technique. A point that one of the reviewers made was that conduction between the exposed thermocouple wires could disrupt the readings. That is certainly possible, and might explain some of the failures at temperatures above 1000 K, like the one shown in the attached diagram. Such a failure is characterised by an initial oscillation in the reading, followed by a drop in output and a later (partial?) recovery as the explosion occurs. It occurs in about a third of the samples.

The thermocouple wires are made of materials that are not particularly good conductors of heat; they are very thin and are heated for only a few seconds. That means that the thermal gradient in the wires (on which the electrical output depends) extends for a very short distance (at most, a few millimetres) beyond the point where the two wires are joined. As the reaction progresses, the grain is composed of Al and CuO (both of which must be molten by the time the temperature exceeds 1400 K) and an increasing amount of metallic Cu. All of them are electrically conductive. It wouldn’t take much conduction, very close to the junction, to disrupt the output. Such an effect is likely to be very dependent on the precise geometry of each sample, which would explain why only some of the samples are affected.

I’m wondering if it would be possible to eliminate – or, at least minimise – the effect by adding some form of insulation. The problem is that it would have to withstand intense heat, if only for a very short time. I thought about heat-resistant paint, but the stuff I have is only effective up to about 1050 K. Perhaps I could coat the wires in something like bentonite, mixed with a little glue to keep it in place. I’d probably have to do that after creating the grain, but before applying the prime. It wouldn’t matter if it were blown off by the explosion, as by that time it would have done its job.

Post by **Lloyd** » Fri Dec 28, 2018 4:18 pm

Soda lime glass might work, too. It becomes liquid at 1090C, but would have done its work (in the short exposure) before de-cladding the junction.

Lloyd

richardh08 · Post by **richardh08** » Sat Dec 29, 2018 12:16 am

That would probably work, but would be much trickier to apply. I certainly couldn't do it _after_ building the grain

)

Post by **Lloyd** » Sat Dec 29, 2018 1:53 am

'Having done quite a lot of glass-blowing for lab apparatus, I think it actually might be quite easy. Heat a TINY vessel of glass to bright-yellow heat, and heat the wire to a similar temperature. Then, just dip the wire in the liquid mass and remove it.

It would cool _almost_ instantly, and should probably form a thin coating on the wires.

Lloyd

richardh08 · Post by **richardh08** » Sat Dec 29, 2018 10:45 am

Yeahbut... I can't think of any reasonable way of doing that which wouldn't also coat the twisted pair itself. I want to keep good thermal contact between the grain and the thermocouple, at least up to the point where the wires separate, and perhaps a fraction beyond. It shouldn't matter if there is an electrical short anywhere inside the grain, as long as it occurs at a point where the temperature is the one I'm trying to measure.

Post by **Lloyd** » Sat Dec 29, 2018 1:58 pm

I can think of a way that _might_ work, but I don't have the resources to try.

That would be to coat all of it, then with the wires held oriented so the junction was up, heat only the junction until any glass on it either ran off or vaporized.

Lloyd

richardh08 · Post by **richardh08** » Sat Dec 29, 2018 8:56 pm

I can see that might work. But forgive me if I try something else first.

Post by **Lloyd** » Sat Dec 29, 2018 9:39 pm

Oh, I shall, Richard! I'm just "thinking off the top of my head". Mine are only meant as more fodder for your thought-processes!

Lloyd

dave321 · Post by **dave321** » Sun Dec 30, 2018 11:13 pm

richard,

i bought a cheap chinese pulse welder a while ago,i am sure it would
"ball" your wire ends up, if you wanted me to try.
the weldeing rod is is 0.5mm tungsten rod.

dave321 · Post by **dave321** » Sun Dec 30, 2018 11:13 pm

richard,

i bought a cheap chinese pulse welder a while ago,i am sure it would
"ball" your wire ends up, if you wanted me to try.
the welding rod is is 0.5mm tungsten rod.

richardh08 · Post by **richardh08** » Mon Dec 31, 2018 1:08 am

Thanks for the offer, Dave. But contact at the twisted pair is no longer a serious problem since I made myself a simple spot welder.

I have to say that I'm still not 100% certain that stray conduction is the culprit - I'll have to run more trials with some kind of insulation in place to see if it makes a significant difference.

richardh08 · Post by **richardh08** » Sat Jan 05, 2019 3:55 pm

The attempt at using Bentonite as insulation was a miserable failure. I had to apply it as a fairly wet paste and was expecting that it would shrink a bit on drying. Well, it shrank a lot and re-exposed the wires in every case.

I'm now trying plaster of Paris, made to a creamy consistency and applied with a fine tipped paint brush. That seems to have worked, but I won't know for sure until it has fully dried. Admittedly, it won't withstand the heat as well as clay, but it only has to survive for a few seconds and won't be subjected to any significant stress until the grain explodes.

I still have to prime the grains, so they won't be ready to test for at least a couple of days. Hopefully, by then, I'll also be clear of the absolute stinker of a cold that I've had for the last three days.

Post by **Lloyd** » Sat Jan 05, 2019 4:06 pm

If that succeeds, then wonderful. If not, may I suggest a fire-clay/Portland cement mixture such as used to lay fire brick in furnaces and fireplaces?
Of course, it might be appropriate to leave out the sand. The other materials are finely-powdered.

Lloyd

richardh08 · Post by **richardh08** » Sat Jan 05, 2019 4:46 pm

That would be my next port of call, if the plaster doesn't work well enough.

Post by **Lloyd** » Sat Jan 05, 2019 8:03 pm

Richard,
In after-thought, the silica in the sand is important to the heat-resistance of the mix. But, of course, the granular nature of it is not conducive to what you wish to do.

I would suggest an 'equal volume' of fumed silica instead of the sand, in order to yield approximately the same insulative power.

Lloyd

richardh08 · Post by **richardh08** » Wed Jan 09, 2019 5:44 pm

The results are in, but not entirely conclusive. I ran trials on two compositions that I've previously had problems with. The first was the all magnalium composition and I still haven't entirely sorted out a consistently effective prime, so not all of them worked properly. But in all cases there was no evidence of a drop in signal. The second was a medium bismuth composition that had previously shown highly irregular thermocouple output once the temperature exceeded about 1200 K. The irregularities were still present, but nothing like as extreme as in some of the earlier trials.

I think I'm on the right track, but more work is needed.

Post by **Lloyd** » Wed Jan 09, 2019 6:24 pm

Congratulations, sir! Progress, no matter how small, is progress.

It's one more 'clue' to the solution, and every one increases your knowledge of the matter.

Lloyd

richardh08 · Post by **richardh08** » Wed Jan 23, 2019 4:22 pm

Today, I received notification that my revised manuscript has been accepted for publication. I'm quite pleased!

I was also invited to submit a suggestion for a cover picture (provided I'm prepared to contribute 800 euros for the privilege

). I think I'll decline the offer

Boophoenix · Post by **Boophoenix** » Wed Jan 23, 2019 7:08 pm

Oh man, they are fond of their privileges!!!

Awesome and congrats on the acceptance.

dave321 · Post by **dave321** » Wed Jan 23, 2019 8:26 pm

congrats richard !! well done

Post by **Lloyd** » Wed Jan 23, 2019 9:30 pm

Yes, Sir Richard! Congratulations on your new 'knighthood'!

(Good job!)

Lloyd

davidg · Post by **davidg** » Thu Jan 24, 2019 12:29 am

Congratulations.

richardh08 · Post by **richardh08** » Thu Jan 24, 2019 12:37 am

Thanks guys.

I would love to say that I was never in doubt that it would be accepted, but I'd be lying!

richardh08 · Post by **richardh08** » Tue Feb 12, 2019 5:00 pm

Got the galley proofs today! They said it would take 3 to 4 weeks and it turned out to be 3 weeks to the day from notification of acceptance. I have some careful reading to do.

They also gave me the option of purchasing reprints - a minimum of 50, at a cost of 640 euros. I doubt I'll take that offer up.

Boophoenix · Post by **Boophoenix** » Tue Feb 12, 2019 9:37 pm

Congrats!

You might consider putting a couple of feelers out for intrest. I’d purchase a copy.

Fulmen · Post by **Fulmen** » Tue Feb 12, 2019 11:28 pm

Wooot, how can you turn down such an honor?

Seriously though, keep up the good work.

richardh08 · Post by **richardh08** » Wed Feb 13, 2019 1:49 am

I appreciate your support guys.

I can't post it in a public forum or make it available in any such systematic way but, once it is formally published, I can send individual copies to any 'colleague' who asks for one.

Yus · Post by **Yus** » Thu Feb 14, 2019 5:52 pm

Where will it be published? Is abstract available? What is "Research and development room"?