Visibility of colors underwater using artificial illumination.
The visibility of various colors underwater with artificial illumination has been measured in three different bodies of water chosen to sample a continuum from clear to turbid. Subjects were Scuba divers who observed the colors at night, using a mercury or an incandescent light source. The visibility results show numerous interactions among color, fluorescence, type of light source, and type of water; from them, it is possible to select the optimum combination to be used under a wide variety of conditions.
The Application of Colour Measurement
Earlier review papers by Hunt [I] and McLaren [2] have dealt with the basic principles of colour measurement and its application to the measurement of colour difference, respectively. This paper is mainly an attempt to assess the present situation on instrumental recipe prediction, but it also includes topics such as whiteness and fluorescence, metamerism, blends of coloured fibres, and the production of colour-separation transparencies in printing. Colour differences are used at various stages of the recipe prediction procedure.
Microwave source with enhanced radiation power based on orbitron MASERs
We have proposed the design of high power microwave source in a vacuum tube based on the theory of negative mass instability. The proposed source does not operate based on a slow-wave structure but instead makes use of accelerated charged particles. In our structure, an electron emitter injects the charged particles into to the cavity. Emitted particles move around the anode, which leads to electron acceleration and emission of electromagnetic waves with a specific frequency. In this paper, we have enhanced the output power and frequency of microwave source by variation of particles initial energy and the number of anodes incorporating their specific arrangement and applied voltages. Working at room temperature, compactness, wide bandwidth, and tunability of output frequency are among the advantages of the proposed source.