# Tag Info

## New answers tagged material-science

1

Yes, depending on the material there might be a difference. I assume you mean a short interval of force applied followed by an hour of rest, not a force applied constantly for an hour. One hour is a long time and allows the material to return to a relaxed state. A shorter time interval will give the material less time to "repair the damage" done by the ...

0

I have consulted the International Tables for Crystallography (which is the authorative reference for symmetries, point groups, space groups and the like; unfortunately, it is not freely available on the web), and as drawn in the question, so the plane group is indeed p1, so no rotation axes. However, it would be nice if you could please clarify how you ...

2

In ferromagnetic materials there is an unpaired electron in the outermost orbital, giving an overall magnetic moment equal to one electron spin to the atom. In a ferromagnetic bulk crystal, these orbitals can overlap between neighbouring atoms which causes the spontaneous magnetisation through the exchange interaction. This interaction is incredibly short ...

1

It's because the electrons in the conduction band are correlated, motion and spin are not uncorrelated since pauli principle is acting, if the spins are opposite the motion can be more "free", but if they point towards the same direction they can be closer (conterintuitevely) Exchange interaction

0

This book has a mathematica script for generating a hysteresis curve in its Appendix. Since I don't have a mathematica licence I tried converting it to python without much success. Do let me know if you get it up and running.

0

I'm only one hour into trying to answer that question myself, and I'm at the same thesis deadline state. this is the best I've found so far: http://vincent.francois-l.be/VINCH_model.pdf Not as simple as I would like! Good luck.

1

In a way, the reciprocal lattice is the Fourier transform of the original lattice. Now it's in the nature of the Fourier transform to change a sub- into a superstructure. That means that the basis vectors (i.e. the sub-structure of your unit cell) in real space lead to a super-structure in reciprocal space. So, the reciprocal lattice vectors define a ...

2

No, this is not possible because the weight of any rope that is the necessary 35 600 km long would very quickly pull the station out of orbit. Furthermore, since the station is effectively weightless in orbit, the act of hoisting something with weight up from the surface would create a reaction force on the station that would again pull it down long before ...

0

The deformation amount is 0.2% to count as yielded for steel Hard steels and non-ferrous metals do not have defined yield limit, therefore a stress, corresponding to a definite deformation (0.1% or 0.2%) is commonly used instead of yield limit. This stress is called proof stress or offset yield limit (offset yield strength): $\sigma t= \frac{F_S}{S_0}$

2

There is no contradiction between the explanation of the tricritical point in the Wikipedia article and the usage of the term in the paper. In the latter, they use a model which consists of several components and exhibits phase transitions. They identify a tricritical point which fits the definition in the Wikipedia article.

2

There could be more to it. I have learned a quite different meaning of "basis" when it comes to crystallography: Of course, lattice vectors are the vectors that span the lattice. Now, at each lattice site, the crystal can have one or more "basis atoms". That's when we speak of a one-atomic, two-atomic basis etc... The positions of the basis atoms are ...

4

When talking about crystal lattices, the lattice vectors are what determines the translational symmetry of the crystal, and you have correctly identified those. The basis vectors are the vectors that tell you where the different atoms in your unit cell are. Thus, the basis vectors are those "locations of atoms A and B": The basis vector for atom B is just ...

1

Basis vectors and lattice vectors are alternative ways to represent vectors in a vector space. In mathematics (linear algebra,) basis vectors are mutually orthogonal and form a set of linearly independent vectors that, in a linear combination, can represent every vector in a given vector space. A set of basis vectors define what we usually think of as a ...

-1

Basis vectors are 3 shortest independent lattice vectors

1

Actually, air itself with different water content and density forms refracting layers that can focus microwaves (and other electromagnetic radiation). This is called "ducting"/anomalous propagation.

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Anything that 2.4Ghz EM waves (microwaves) will pass through that has a different index of refraction than air can be used as as a lens or prism. A really common material for this is wax. Also, you can reflect microwaves using metal surfaces. This is how a satellite dish works. For a simplified model of your wifi router, you can think about the ...

0

If you take, for example, a perfect metal sphere then it has a work function that is the energy required to remove an electron from the metal to infinity. If you start charging the sphere by adding electrons to it then the work function decreases, and above some limiting charge the work function falls to zero. This means any more electrons you add to the ...

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