Axial centering force

Radial Magnetic Pull and Axial Centering Force. 

Note Couplings with axial elastic centering forces are usually satisfactory without these precautions. 

The problem of calculating the modulus of elasticity of nanoparticles loaded with axial concentrated forces applied at opposite ends of the diameter is axially symmetric. Therefore, the values of longitudes in this case can be ignored. We denote a as the latitude measured from the radius drawn from the center of the ball to one of the two opposing points of application of concentrated forces on the surface (Fig. 4.7). 

In an attempt to aid interpretation of the IR spectrum of MbCO we decided to model the full protein by use of a hybrid quantum mechanics/molecular mechanics approach (QM/MM), to evaluate changes in the CO stretching frequency for different protein conformations. The QM/MM method used [44] combines a first-principles description of the active center with a force-field treatment (using the CHARMM force field) of the rest of the protein. The QM-MM boundary is modeled by use of link atoms (four in the heme vinyl and propionate substituents and one on the His64 residue). Our QM region will include the CO ligand, the porphyrin, and the axial imidazole (Fig. 3.13). The vinyl and propionate porphyrin substituents were not included, because we had previously found they did not affect the properties of the Fe-ligand bonds (Section 3.3.1). It was, on the other hand, crucial to include the imidazole of the proximal His (directly bonded to the... 

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