A major thrust of Dr. Maynard S Dewey’s research is focused on precise measurements of decay parameters in neutron beta decay in order to probe the Standard Model (e.g. the neutron lifetime and the correlation between the outgoing electron and electron-antineutrino momenta). This includes precise measurements of thermal and cold neutron fluences in order to reduce the uncertainty in beam-type measurements of the neutron lifetime, to measure important neutron capture cross sections (e.g. boron and lithium), and to re-calibrate the national neutron source NBS-1 which underpins our neutron source and detector calibration services. A second thrust is precise measurements of neutron source intensities using the manganese bath method in order to reduce the uncertainty of neutron source calibrations for industry and government.