Mode-Selective Properties of a Metal-Clad-Dielectric-Slab Waveguide for Integrated Optics

Attenuation and phase constants are calculated for a metal-clad-dielectric-slab waveguide and the results show the behavior of the propagating modes as a function of cladding material and dielectric. Analysis indicates that the dielectric properties influence the attenuation and cutoff frequencies whereas the metal cladding influences primarily the attenuation of propagating modes. Variation of the attenuation and phase constant around a center frequency show surface-wave properties of the TM0 and TM1 modes

Best After Rain: Waterfall Discharges and the Tourist Experience

Waterfalls attract tourists because they are aesthetically appealing landscape features that are not part of everyday experience. It is generally understood that falls are usually seen at their best when there is a copious flow of water, especially after heavy rain. Guidebooks often contain this observation when referring to waterfalls, sometimes warning readers that the flow may be severely reduced during dry periods. Indeed, many visitors are disappointed when they see falls at such times. Some are saddened when the discharge of a waterfall has been depleted by the abstraction of water upstream for power generation or other purposes. While, for those in search of the Sublime or merely the superlative, size is often important, small waterfalls can give great pleasure to lovers of landscape beauty. According to guidebooks, however, even these falls are usually best seen after rain. Drawing on tourist and travel literature and personal journals from the eighteenth century to the present, and with reference to examples from different parts of the world, this paper discusses the importance of discharge in the tourist experience of waterfalls