The Doppler effect is a phenomenon which relates the frequency of the harmonic waves generated by a moving source with the frequency measured by an observer moving with a different velocity from that of the source. The classical Doppler effect…

Obtaining holographic volume gratings with high diffraction efficiencies that can be used under white light has been a serious problem for the polyvinyl alcohol-acrylamide-based photopolymers developed by other researchers. In this paper we propose to eliminate the residual monomer in…

Bleached holograms are one of the most interesting techniques used to produce phase holograms of high quality on photographic emulsions. Of particular interest is the method of fixation-free rehalogenating bleaching. Using Kogelnik's coupled-wave theory we shall obtain information about the…

Kogelnik's coupled-wave (CW) theory has been used for decades to predict the diffraction efficiency of volume diffraction gratings. Although this theory has been applied with success to volume diffraction gratings recorded under a great variety of experimental conditions, its predictions…

El debate sobre el desarrollo del turismo sostenible por lo general se centra en las prácticas turísticas a pequeña escala, como el turismo rural o el ecoturismo, inadecuadamente llamadas turismo "alternativo”, a juzgar por los problemas que empiezan a crear.…

We present three ways of treating the problem of fluid flow in a hollow cylinder. One method involves a differential equation, and the other two involve more physical insight. We discuss the relative advantages of each method., The following article…

Cables are one of the common structures studied in a first-year engineering mechanics course (statics), since the flexible cable is one of the usual methods of supporting loads. For example, the suspension bridge has been used for many centuries and…

Total quality management (TQM) has been developed around a number of critical factors. However, TQM is much more than a number of critical factors; it also includes other components, such as tools and techniques for quality improvement. In this paper,…

Two new species of Enclisis Townes, 1970 from Spain are described and illustrated: E. dichroma sp. n. and E. schwarzi sp. n. The new species are distinguished from the closest species E. infernator and E. ornaticeps by head and leg…

The classical problem of deflection of a cantilever beam of linear elastic material, under the action of an uniformly distributed load along its length (its own weight) and an external vertical concentrated load at the free end, is experimentally and…