The level structures of some single closed shell nuclei (⁸⁷₃₇Rb₅₀ and ⁸⁸₃₈Sr₅₀) and nearly closed shell nuclei (⁸⁷₃₈Sr₄₉ and ⁸⁸₃₇Rb₅₁) have been determined by means of beta decay processes of ⁸⁷Kr, ⁸⁸Kr and ⁸⁸Rb to final states ⁸⁷Rb, ⁸⁸Rb and ⁸⁸Sr respectively, and by means of the thermal neutron capture reaction on strontium (⁸⁶Sr(n,ɣ)⁸⁷Sr and ⁸⁷Sr(n,ɣ)⁸⁸Sr). The gamma radiation was studied using a Ge(Li) spectrometer and a Ge(Li)-NaI(Tl) coincidence spectrometer. Beta groups were identified using a plastic scintillator and a plastic-NaI(Tl) coincidence spectrometer. Spins and parities were determined for some of the levels from the deduced decay schemes. / Thesis / Doctor of Philosophy (PhD)