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…

The photopolymerization diffusion models give accurate comprehension of the mechanism of hologram formation inside photopolymer materials. Although several models have been proposed, these models share the common assumption that there is an interplay between the processes of monomer polymerization and…

The use of bleaching techniques is perhaps one of the most popular methods of creating phase holograms from holographic emulsions. In this paper we will study the influence of the different experimental conditions on the refractive index modulation created inside…

Realizou-se um estudo sobre a ação biocida de Eucalyptus citriodora, Eucalyptus globulus e Eucalyptus staigeriana no carrapato Boophilus microplus, buscando-se a produção de acaricidas menos agressivos ao meio ambiente. Os óleos essenciais das três espécies e os concentrados emulsionáveis de…

Este experimento foi conduzido para avaliar o valor nutricional (matéria seca e proteína bruta) de seis genótipos de sorgo para silagem, com e sem tanino no grão, colhidos no estádio de grão farináceo, utilizando a técnica da degradabilidade in situ.…

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…

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…

Photographic emulsions are still widely used to record holographic optical elements. In particular, if high diffraction efficiencies are needed, phase volume holograms are preferably recorded on these emulsions. Two particular techniques producing high-quality volume phase holograms are fixation-free rehalogenating bleaching…

Accurate recording of computer-generated holograms (CGH) on a phase material is not a trivial task. The range of available phase materials is large, and their suitability depends on the fabrication technique chosen to produce the hologram. We are particularly interested…

Desalination of seawater has become an important and growing
industry due to the water shortage in some Mediterranean countries. This
activity may result in environmental impacts, mainly generated by the
discharge into the sea of the concentrate (brine) produced. Data…