FLUORESCENCE PROPERTIES OF ETHENOTHIAMINE*

Abstract— The absorption and fluorescence properties of ethenothiamine in neutral and acidic solution are reported, and some are found to be in contradiction to previous findings. The low fluorescence quantum yields of ethenothiamine make it a poor substitute for the vitamin in biological systems.     

Stability of the flow around a cylinder: The spin-up problem

In this paper the evolution of vortical disturbances withina boundary layer occurring at a circular cylinder is discussed.As the body starts to spin around its generator a temporallygrowing layer results and the underlying centrifugal natureof this system allows Taylor-Görtler vortices to develop.The initiation of these modes is caused by axially symmetricwall imperfections, and so this constitutes a receptivity problem.For vortices of order one wavenumber a vortex wedge is formedand the final structure of this mode is determined by a right-handbranch calculation. The inviscid limit of the calculation isalso discussed and this may well be relevant to modes with orderone wavenumber introduced after the layer has partially evolved.