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We discuss, in terms of 1D and 2D micromagnetic models, the basic characteristics of the demagnetization mechanisms acting in hard magnetic materials. This includes the study of the hysteretic and relaxational processes and, particularly, the investigation of the temperature dependence of coercivity. From our results we conclude that, even in highly anisotropic materials, demagnetization should be described in terms of nucleation and propagation of finite magnetic moment structures of the domain wall type.

A well-posed magnetic imaging method based on magnetic relaxation of magnetic nanoparticles is used for obtaining high-spatial resolution image of magnetic tracers. An image of superparamagnetic iron oxide nanoparticles tracer is obtained from mapping the magnetization decays and the imaging capability is shown by using gamma-ferric oxide magnetic nanoparticles.

An off-resonance TS-[R.sub.1rho] experiment for quantifying microsecond time scale chemical exchange in [[super 2]H]. [super 15N]]-enriched proteins is presented. The TS-[R.sub.1rho] experiment efficiently suppresses cross-relaxation between the doublet components of spin-locked [super 15]N magnetization and allows accurate measurement of the chemical exchange contribution to the slowly relaxing doublet component.

The average technique is used for the analysis of magnetization relaxations to equilibrium. The averaging technique is compared with the numerical solutions of the Landau-Lifshitz equation and found to be leading to the first order separable differential equation for the free energy that can be used instead of the Landau-Lifshitz equation to study magnetization relaxations.