In the first part of this thesis, it is demonstrated that frequency-swept pulses can be used for the purposes of exciting and transferring spin polarization between dipolar-coupled protons and half-integer quadrupolar nuclei using the broadband adiabatic inversion cross polarization (BRAIN-CP) pulse sequence. With the aid of numerical simulations and experimental tests, it is shown that significant increases in the S/N ratio of UW NMR powder patterns are possible. Additionally, strategies are discussed for collecting high-quality UW NMR spectra with applications to a wide range of materials. In the second part, new methods are described for resolving individual UW NMR spectra associated with magnetically distinct nuclei by exploiting their different relaxation characteristics using 2D relaxation-assisted separation (RAS) experiments. These experiments use a Tikhonov fitting algorithm to produce high-quality T1 and T2 relaxation datasets, which in turn yield high-resolution, 2D spin-relaxation correlation spectra for both spin-1/2 and quadrupolar nuclei.
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