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What is an "As-grown crystal"?

Jon Custer's comment is correct. As-grown means the crystals were grown according to a specific recipe, and then were not modified further. Examples of not as-grown would be if you annealed the ...
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Why are HCP materials brittle while FCC materials are ductile?

Interesting. In my past metal physics thermodynamics lab research work the focus was on yield stress which here characterises the shift from ductile to brittle deformation. Mechanical engineers also ...
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2 votes

How do we justify that potential energy in a spring is Galilean invariant (to the extent that Newtonian mechanics holds)?

From this I surmise that the elastic potential energy of a compressed spring can be ultimately reduced down to electromagnetic energy. Well, yes, but you have to use the quantum mechanical rules of ...
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1 vote

How do we justify that potential energy in a spring is Galilean invariant (to the extent that Newtonian mechanics holds)?

The potential energy of a spring is given by $U=\frac{k \Delta x^2}{2}$. Consider the Galilean transformations applicable in 1 dimension: Uniform motion, with velocity $\vec{v}$, is defined by $(\...
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Cooperative orders

The degrees of freedom in charge order and orbital order are exactly that; the charge and orbital degrees of freedom. For example, a charge density wave would be an example of charge order. For ...
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Terminology: does this situation correspond to an anisotropic but linear dielectric?

Isotropy means that the relation between $\vec D$ and $\vec E$ is independent of the direction of $\vec E$. This also implies that $\vec D$ is parallel to $\vec E$: $$\vec D = \vec D (E) \hat E.$$ ...
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Terminology: does this situation correspond to an anisotropic but linear dielectric?

100 percent correct. A material is linear when the material law is what a mathematician will call a linear mapping, i.e. $$ \vec{D}\left(\vec{E}+\lambda \vec{E}'\right) = \vec{D}\left(\vec{E}\right)+\...
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1 vote

Terminology: does this situation correspond to an anisotropic but linear dielectric?

Yes, I would call this situation a linear dielectric: From Electrostatic Fields in Matter: Materials in which the induced polarization is proportional to the electric field are called linear ...
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2 votes

Shouldn't length contraction cause friction under certain circumstances?

I don't think it's all that complicated. Let’s assume that in your train problem there is a rack and pinion action between the train wheels and the track instead of friction. Assume that the speeding ...
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Can I dip Stainless Steel Heat Exchangers in Milk?

One of the reasons for the development of type 316 and 316L stainless steels was their superior corrosion resistance in milk exposure, so you should be OK.
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1 vote

Confusion in Derivation of Excess Pressure in a Cylindrical Drop

Simple Answer: Assume that $l>>R$. You will get the answer in single step. Complicated Reality: Liquid would not form cylendrical shape on its own. The ends are not going to be flat plates that ...
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1 vote

Confusion in Derivation of Excess Pressure in a Cylindrical Drop

That's a good start, however there are some subtleties behind treating surface tension as a force. Indeed, there are some classic problematic cases that are often overlooked at first. The best way to ...
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What is the largest hollow structure that could be made before gravity becomes a problem?

Any size works. The mass of your spherical shell grows like its area, i.e. like radius $r^2$. But gravity drops like $1/r^2$, and the gravitational field of any spherically symmetric mass distribution ...
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1 vote

Shouldn't length contraction cause friction under certain circumstances?

This question is complicated by using accelerated frames (not just one but two differently accelerated frames, one for the front and one for the back of the train) plus the unintuitive weirdness that ...
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What are some reputable databases for the measured values of the physical properties of materials?

The CRC Handbook of Chemistry and Physics is the "industry standard" and should be appropriate for most layman purposes including those listed. Some knowledge of basic physics is assumed. ...
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Which naturally occuring solid material has the lowest refractive index?

If dielectric films are included, North Carolina State University researchers announced "a film made of aluminum oxide that has a refractive index as low as 1.025 but that is mechanically stiff&...
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Calculating bulk modulus from interatomic potential on cubic lattice

A little bit of pedantry first: NaCl has a face-centered cubic lattice structure with 2 atoms in the basis (1 Na and 1 Cl), which looks like a simple cubic structure only if we ignore that there are ...
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