Monochromatic colors

Electronic Film Output. Imagesetters are precision electromechanical devices that image monochromatic color separations onto photographic film or paper. Each separation is used to expose a printing plate for a single ink color (4). 

Once we have done this, we now have our three primary colors in the form of standard lamps, and can proceed to determine Items 1,2 3, given above on page 421. To do this, we vary the wavelength of the monochromatic light, and determine relative amounts of red, green and blue light required to match the monochromatic color. This is done, as stated before, for about 5000 observers. 

We need about 5000 observers to obtain a satisfactory average, both for the dark-adapted and the light-adapted hiunan eye. Note that we can compare any color In terms of red -i- green -i- blue to a monochromatic color. 

Monochromatic color scheme n. Combining of colors in a room based on one color used in various values and saturation or chromas. 

The cholesteric phase maybe considered a modification of the nematic phase since its molecular stmcture is similar. The cholesteric phase is characterized by a continuous change in the direction of the long axes of the molecules in adjacent layers within the sample. This leads to a twist about an axis perpendicular to the long axes of the molecules. If the pitch of the heHcal stmcture is the same as a wavelength of visible light, selective reflection of monochromatic light can be observed in the form of iridescent colors. 

The visible spectnun extends from about 4000 A to 7000 A. We find that the eye acts as an integrating instrument. Thus, two colors may appear equal to the eye even though one is monochromatic light and the other has a bcuid of wavelengths. This is shown in the following diagram ... 

Define "color" in terms of % red, % green and % blue, as compared to monochromatic radiation... 

The advantage of chromaticity coordinates is that we now have a set of nonnalized values which we can use to compare colors having different intensity values (and thus different energy values as weU). Furthermore, we need only specify x and y since x + y + z = 1.00. This allows us to specify monochromatic radiation in terms of our chromaticity coordinates. Actually, we can plot a three-dimensional value on a flat (2-dimensional) surface. 

Since monochromatic radiation is a boundary of color-mixing, then we can construct a CHROMATTCriY COORDINATE DIAGRAM in terms of x and y 7.8.26.-... 

Note that the diagram is bounded, as we have already stated, by the values of monochromatic light. Thus, we can find any color, be it monochromatic or polychromatic, in terms of its x and y coordinates. 

Instrumental color measurements eliminate subjectivity, are more precise, take less time, and are simpler to perform. However, to evaluate instrumental results properly, the physics of the measurement processes must be considered. Three types of color measurement instruments are used for food the monochromatic colorimeter, the tristimulus colorimeter, and the colorimetric spectrophotometer. 

In this chapter, photoelectrochemical control of size and color of silver nanoparticles, i.e., multicolor photo-chromism [1], is described. Silver nanoparticles are deposited on UV-irradiated Ti02 by photocatal5dic means [2]. Size of the nanoparticles can be roughly controlled in the photocatalytic deposition process. However, it is rather important that this method provides nanoparticles with broadly distributed sizes. The deposited silver nanoparticles are able to be dissolved partially and reduced in size by plasmon-induced photoelectrochemical oxidation in the presence of an appropriate electron acceptor such as oxygen. If a monochromatic visible light is used, only the particles that are resonant with the light are dissolved. That is, size-selective dissolution is possible [3]. This is the principle of the multicolor photochromism. 

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