If you mean that anisotropy and hysteresis are unrelated phenomena, I consider enough the proof of post#301.
Due to I can't argue about polymers against Dr. Polymer, I will show evidence from other people, I hope you don't mind.
And this paper illustrates with more detail dielectric properties of some classes of polypropylene.
http://www.google.com.ar/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDIQFjAA&url=http%3A%2F%2Fwww.scirp.org%2Fjournal%2FPaperDownload.aspx%3FDOI%3D10.4236%2Fgsc.2012.22006&ei=L3l1U7iOFqLjsAT0j4Fg&usg=AFQjCNG9CtDRenlywl1HF2FPgUVieXuhYA&bvm=bv.66699033,d.cWc&cad=rja
About polypropylene dielectric anisotropy
http://www.google.com.ar/url?sa=t&r...0xCcVtWB2CB8Fjg&bvm=bv.66699033,d.cWc&cad=rja
http://www.tandfonline.com/doi/abs/10.1080/00914030108048843#preview
Also polyethylene terephthalate shows dielectric anisotropy
Anisotropy of mechanical and dielectric relaxation in oriented poly(ethylene terephthalate) - Davies - 2003 - Journal of Polymer Science Part A-2: Polymer Physics - Wiley Online Library
Even paper exhibits dielectric anisotropy
Measurement of the Dielectric Properties of Paper: ingentaconnect
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So, let's see, Mike Chung's paper (and Mike is very good, we were in the same research group) was about derivatized PP, not the same thing as PP. The Slovak paper was looking at optical dichroism at a 1-2 micron scale.
The Jawad paper was closer to the mark, but was looking at copolymers that were die drawn, as opposed to the cast film BOPP methods used in cap film manufacturing. Yes, there's chain alignment in MD, greatly reduced in the BOPP process (and even further with annealing and shrinking) but that's orthogonal to the applied field which itself has translational symmetry along the other two axes.
Likewise, the PET paper is measurements on films that are deliberately oriented, a lab technique, not at all the the same as the cast PET used in caps. If you have a pair of scissors and one of those plastic ring deals used to hold together six-packs of beverage cans, I can walk you through an experiment which might clarify things.
The Jawad paper was closer to the mark, but was looking at copolymers that were die drawn, as opposed to the cast film BOPP methods used in cap film manufacturing. Yes, there's chain alignment in MD, greatly reduced in the BOPP process (and even further with annealing and shrinking) but that's orthogonal to the applied field which itself has translational symmetry along the other two axes.
Likewise, the PET paper is measurements on films that are deliberately oriented, a lab technique, not at all the the same as the cast PET used in caps. If you have a pair of scissors and one of those plastic ring deals used to hold together six-packs of beverage cans, I can walk you through an experiment which might clarify things.
The cases of applied field normal or parallel to symmetry axis differ on losses, I guess that capacitor manufacturers choose dielectric materials in order to reduce losses, i.e. the area inside hysteresis loop.
Again, anisotropy and nonlinearity are necessary conditions for hysteresis, then anisotropy and hysteresis are not unrelated phenomena.
If you are denying this, is fine.
If you are saying that my arguments about polymers are wrong, is also fine, I have no idea about them, so I would say that you are right.
Yes, sure, Landau-Lifshitz “Electrodynamics Of Continuous Media” - Course of Theoretical Physics Vol 8 - Chapter V, §37, page 149, 150 and 151.
Electrodynamics of continuous media - Лев Давидович Ландау, Evgeniĭ Mikhaĭlovich Lifshit︠s︡ - Google Books
Warn you that the English translation is horrible, so I use the French translation.
Electrodynamique Des Milieux Continus de L & E LANDAU & LIFCHITZ
Chapter V, §37, page 199, 200, 201 and 202.
As an example of horrific translation, at page 151, says
In the French translation, at page 202, says correctly
Now, authors really do know what they are talking about…
Hey, they were Landau and Lifshitz, what else do you expected? Geniuses!!!
However, an easier rough demonstration here
http://www.diyaudio.com/forums/tubes-valves/207544-ecc82-12au7-line-preamp-31.html#post3931197
Although not literal, your translation reflects more accurately the idea.
The English translation "is as if" authors say "we have no idea about hysteresis"
Is as if the book wasn't written by Landau and Lifshitz, but by "The three stooges"
Or even worse, is as if it were translated by me, in Tarzan-English.
Landau-Lifshitz books, stand out above the rest by the originality of their approaches.
Chapter V begins mentioning that anisotropy of the magnetic properties of ferromagnetics is due to the relativistic interactions between their atoms, later, the anisotropy is described by the addition to the thermodynamic potential of the magnetic anisotropy energy.
Sadly, a brilliant work, is opaqued by a bad translation of the last sentence on a footnote.
Really? I don't think so.
Maybe if you change ";" by "when"
Maybe it is subtle, or maybe my Tarzan-English is also delirious.
Yes, that is what I understand it to mean. Perhaps as a native English speaker I have misunderstood them?00940 said:
Where is the (alleged) link between hysteresis and anisotropy? The quote says that they are not going to deal with hysteresis mechanisms, so in what sense does the book confirm the alleged mechanism?
You are right, I often use the term ignore in its ancient meaning, i.e. related to ignorance, in the sense "be ignorant of"
ignore: definition of ignore in Oxford dictionary (British & World English)
However both meanings exist, see meaning/synonym 5 here
ignore - definition of ignore by the Free Online Dictionary, Thesaurus and Encyclopedia.
Regardless, I am still thinking that the translation is wrong, but this is just semantic.
I would prefer a technical discussion, so no more comments about semantic.
If "the mechanism of hysteresis effects which may be related to defects in the crystal, the internal stresses in the sample, the polycrystallinity, etc.." doesn't sounds to anisotropy, please, simply just read the book.
Reading/learning experience is not transferable, you must read the book for yourself.
Without any intention to offend you, I would say that your attempt to cover the sun with your hand has ceased to be serious.
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Totally agree, it became on some kind of trolling, and I would like to keep on going with the ECC82 preamp, so just in case, the last recommended lectures
http://ocw.mit.edu/courses/material...-2013/lecture-notes/MIT3_024S13_2012lec24.pdf
http://ocw.mit.edu/courses/material...-2013/lecture-notes/MIT3_024S13_2012lec25.pdf
http://www.google.com.ar/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDUQFjAB&url=http%3A%2F%2Fwww.ifmpan.poznan.pl%2F~urbaniak%2FWyklady2012%2Furbifmpan2012lect5_03.pdf&ei=uqB7U-H9IsnxoATG34LIBg&usg=AFQjCNFgFXqOwNUa58t9qDNoqPqtr1i2CA&bvm=bv.67229260,d.cGU&cad=rja
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You may do so, but you need to be aware that native English speakers do not and neither (presumably) do competent technical translators. It would be wise if you henceforth understood "ignore" to mean 'I am aware that there is an issue but I choose to not deal with it' rather than 'I am not aware that there is an issue' - that way you may get what the writer actually intends you to get.popilin said:
It doesn't sound like anisotropy, but what do I know - I am only a physicist.
As far as I can gather, your quotes from the book tell us two things:
- in one place the authors choose not to deal with mechanisms for hysteresis
- in another place the authors mention some of the possible mechanisms for anisotropy in ferromagnets
In what sense does this confirm that hysteresis necessarily arises from anisotropy? (I know I am going to regret asking this!)
I gave you a fundamental argument here
http://www.diyaudio.com/forums/tubes-valves/207544-ecc82-12au7-line-preamp-24.html#post3923583
I gave a rough demonstration here
http://www.diyaudio.com/forums/tubes-valves/207544-ecc82-12au7-line-preamp-31.html#post3931197
At your request, I suggested you an amazing book, where is clearly exposed how anisotropy and hysteresis are related, regardless to semantic irrelevant issues.
Unlike you, I am just a TV repairman, but unlike you, I already read the book.
I have the strong suspicious that you don't want to take the trouble to read the book, neither the very understandable MIT OpenCourseWare lectures, cited on post#333
Once you have read everything, if you still do not understand, at your request, I will explain again to you how anisotropy and hysteresis are related, based on those books/lectures.
BTW, another book where some false assumptions/misunderstandings, even inside scientific ambit, are explained in detail.
Introduction to the Theory of Ferromagnetism (International Series of Monographs on Physics): Amikam Aharoni: 9780198508090: Amazon.com: Books
As I said before, reading/learning experience is not transferable, and I can't read the books for you, unless you read them, and I say that with all due respect, your rhetoric argument is just pettifoggery.
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I see no argument, fundamental or not; I merely see an assertion:popilin said:
There you appear to assume what you are trying to prove.
So 'clearly exposed' that you can't give us a relevant quote, yet presume to give us a spoof English lesson?
Then we must remember that the things from which you claim support are speaking of magnetism not dielectrics. Argument from analogy can be helpful, but it can also lead people astray. As magnetic and electric fields have fundamentally different geometry one must proceed very carefully with analogies!
This correspondence is closed.
Yes and no. Yes, magnetic and electric fields are different. No hysteresis is a universal concept and implies anisotropy.
It's easier to see this just defining hysteresis according to its original meaning: physical variable (electric polarization P in the case of dielectrics) lagging behind changes of what is causing it (electric field in the case of dielectrics).
As the polarization in REAL capacitors ALWAYS lags behind the applied electric field (because the response to an applied field in NEVER instantaneous) once the field is removed there will be a residual polarization which depends on the materials properties. Typically, the residual voltage is about 1% for polymer capacitor (actually quite less for best types) and up to 15-20% for electrolytic capacitors. The lag depends on the materials properties and thus one can describe the polarization as the sum of an induced polarization that depends on the electric field and a residual polarization independent of the electric field. If there is a polarization component which does not depend on the electric field it means that there is a dielectric anisotropy just like the magnetic anisotropy in ferromagnetic material. The residual voltage can take a short or long time to disappear depending on the dielectric type and leakage.
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Indeed, an argument usually is composed by a series of assertions, as you misquoted my argument, only remains an assertion, simple logic.
Furthermore, that argument is not entirely mine, my support is the book of Amikam Aharoni "Introduction to the Theory of Ferromagnetism", a few "bla-bla-bled" to my taste, but very advisable.
BTW. I always try to write vectors with bold characters, just in case you want to misquote me again.
In physics, things don't work this way, you need more than rhetoric to refute my demonstration.
Landau was highlighted by his style, brilliant, clear, accurate and concise, however I cannot synthesize an entire chapter on a few lines, you ask me too much.
This is not the first time you ask me for a "relevant quote"
Due to my Tarzan-English, I am the less appropriate on the planet, even to give a spoof English lesson, however, what amazes me is that nobody, both English and French native language realized that, regardless of the "ignore" meaning, the English translation is wrong anyway
Then we must remember that my first assertion was about dielectrics, but the origin of our discussion was more general
Your request was also general
Mind you that first part of my own demonstration was general, and the second part was for dielectrics in particular.
I also consider it a closed case, although your gross conceptual error, the ideas exchange is always enriching.
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Hysteresis is material related. The Science of hysteresis is one general theory and applies to both dielectrics and magnets.
The sample preparation issue has not necessarily a role in hysteresis. Dislocations, defects and similar things in principle cause energy storage which has nothing to do with hysteresis (and the relative hysteresis loss) in principle. Dislocations, defects etc. might have a role in practice but not necessarily and they can be neglected tout-court in theory for a structurally perfect material. Structurally perfect materials can have hysteresis anyway.
Practical materials for capacitors do have hysteresis loss to some extent, some very small and some more, and this mostly is caused by the lagging of polarization respect to the applied electric field which allows to describe polarization in terms of field dependent and field independent components of total polarization. If there is a field independent polarization then there is anisotropy. I think you confuse field dependence with time dependence. Actually I am pretty sure.
I think you have to go back to school and then you might be able to re-enter the debate!
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