The "primitive unit cell" is the one that allows you to reproduce the whole crystal structure, given you know the space group and the atomic positions of the different types of atoms, while if you have the "unit cell" you don´t need any additional information to reproduce the crystal structure...
Al is indeed very reactive. However, usually it is covered by a thin and compact oxide layer. If you remove that layer and assure it is not formed immediately (e.g. rubbing the surface of the metal with mercury or mercury nitrate), the metal behaves more or less like magnesium, reacting...
No, strength doesn't change. It is a material property independent on geometry. Strength is measured as force per unit area. What changes when you increase the cross section is the force necessary to break the material, not its strength. Strength to force is like density to weight. When we say...
The answer is easy. Two atoms do not form a cell but what is called an asymmetric unit: http://en.wikipedia.org/wiki/Crystal_structure#Unit_cell
The unit cell is obtained from the asymmetric unit by applying symmetrical operations.
Imagine a cylinder that starts to rotate in a fluid (similarly to a rotational viscosimeter with concentric cylinders geometry) reaching quickly a fixed velocity. If the fluid is very viscous, only a thin layer near the cylinder will reach appreciable velocity, so stationary state will be...
Of course the polymer chains are not straight but I am pretty sure the antenna formalism still could be applied in your case. I have read quite a few articles about development of branched organic molecules for use as energy harvesting antennas. The idea is that a molecule with a large...
Just an idea: The polymer chain with conjugated bonds may act as an optical antenna and therefore resonance wavelength is comparable to chain length. Absorption has to do with antenna efficiency (losses).
These lamps contain a gas mixture under low pressure. Initially applying a strong electric field it is ionized in an avalanche-like process and afterwards ions conduct current in a similar fashion as liquid electrolytes.
Hi, I think you can use finite elements or finite difference to solve this. It reminds me electromagnetic problems where you have coupled differential equations (Maxwell equations) which you can solve numerically by finite elements or finite difference time domain methods. The following...
As already said, TiO2 is insoluble in water in the sense of decomposing into free ions. However, with sufficiently small particles and appropriate dispersants you can obtain relatively stable suspensions. In the case of very small particles, i.e. nanosized ones the suspension is called colloidal...
"Dissolve" and sometimes "solve" is often used as a synonym of disperse. So if you mean that you are unable to obtain a stable dispersion of your nanopowder, you should try adding a dispersant.