n-propylsalicylidene based on silica as ion exchanger (ie) was used for the separation by complexation of mn2+, co2+, ni2+, cu2+, hg2+, cr3+, fe3+, and uo22+ from their parent solutions. ie and its metal complexes are characterized by elemental analysis, electronic and infrared spectra, in addition to thermal analysis in atmospheric pressure. the mode of chelation and the proposed geometric str...

xx Signed statement xxv Acknowledgements xxvi

A direct comparison was made between the air kerma primary standards used for the measurements of low-energy x rays at the National Institute of Standards and Technology (NIST) and the National Physical Laboratory (NPL). The comparison was conducted at the NPL using NPL reference radiation qualities between 10 kV and 80 kV. The results show the primary air-kerma standards to agree within 0.6 % ...

Thomas Reid (1710-1796) offers an under-appreciated account of the primary/secondary quality distinction. He gives sound reasons for rejecting the views of Locke, Boyle, Galileo and others, and presents a better alternative, according to which the distinction is epistemic rather than metaphysical. Primary qualities, for Reid, are qualities whose intrinsic natures can be known through sensation....