Instrumentation and Methodology -- Saturation Recovery EPR -- Loop-Gap Resonators -- EPR Interfaced To Rapid Mixing -- Application of Angle-Selected Electron Nuclear Double Resonance to Characterize Structured Solvent in Small Molecules and Macromolecules -- Solution-ENDOR of Some Biologically Interesting Radical Ions -- Electron-Electron Double Resonance -- Digital Detection by Time-Locked Sam…