Nuclear magnetic resonance computer specifications

It is unreahstic to attempt the use of the Fourier series or of the Fourier integral transforms without the aid of a computer. In recent years a fast Fourier transform (FFT) algorithm for computers has become widely used. This is particularly useful in certain kinds of chemical instrumentation, specifically nuclear magnetic resonance and infrared absorption spectrometers. In such instruments the experimental observations are obtained directly in the form of a Fourier transform of the desired spectrum a computer that is built into the instrument performs the FFT and yields the spectrum (see Chapter XIX). 

Proton nuclear magnetic resonance (NMR) has also been investigated as a means of characterizing low molecular weight molecules.Metabolic profiles have been generated and, using sophisticated computer analysis, distinctive patterns of molecules have been associated with damage to specific parts of the nephron. It is expected that this technique can be used to identify individual molecules for which selective assays can then be developed. 

Abstract We present in this contribution results from Molecular Dynamics (MD) simulations of a chemically realistic model of 1,4-polybutadiene (PB). The work we will discuss exemplifies the physical questions one can address with these types of simulations. We will specifically compare the results of the computer simulations with nuclear magnetic resonance (NMR) experiments, neutron scattering experiments and dielectric data. These comparisons will show how important it is to understand the torsional dynamics of polymers in the melt to be able to explain the experimental findings. We will then introduce a freely rotating chadn (FRC) model where all torsion potentials have been switched off and show the influence of this procedure on the qualitative properties of local dynamics through comparison with the chemically realistic (CRC) model. 

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