Frequency and color

EXAMPLE 1.1 Frequencies and colors of maximum sensitivity for the human eye. 

In fireworks displays, light of a given wavelength indicates the presence of a particular element. What are the frequency and color of the light associated with each of the following ... 

Since the perception of frequency and color/luminance can be manipulated easily by image processing algorithms, the cues presented in the following sections are suitable to manipulate the perceived depth in 2D images and videos. 

TABLE 1.1 Color, Frequency, and Wavelength of Electromagnetic Radiation ... 

The color of light depends on its frequency and wavelength long-wavelength... 

It has become recognized during recent years that the color of dyes is associated with the resonance of electric charge from atom to atom of the dye molecule.2,3> 4 6 6 Because of the complexity of the problem, however, it has not been easy to expand this idea into a theory of color permitting the rough quantitative calculation of the frequencies and intensities of the absorption bands of dyes. I have now developed a theory of this nature the theory and some of the results of its application are described briefly in the following paragraphs. 

C07-0111. Barium salts in fireworks generate a yellow-green color. Ba ions emit light with A = 487, 514, 543, 553, and 578 nm. Convert these wavelengths into frequencies and into energies in kJ/mol. 

C07-0112. The bright red color of highway safety flares comes from strontium ions in salts such as Sr(N03)2 and SrC03. Burning a flare produces strontium ions in excited states, which emit red photons at 606 nm and at several wavelengths between 636 and 688 nm. Calculate the frequency and energy (kJ/mol) of emissions at 606, 636, and 688 nm. 

The frequency range of short radio waves overlaps with that of long wave microwaves — from about 1 m to about 100 pm. Microwaves are of high technical importance. They cover the radar frequencies and the frequencies at which cellular (mobile) telephones work. Their impacts on food colorants, foods, and biological materials are similar to those of radio waves but the warming effect is more distinct. If microwave use is limited to the topics discussed in this book, no precautions are necessary. 

FIGURE 4.4 Example of 2D separations of five homologous series having (a) constant phase (red vector in inset) and uncorrelated frequencies and (b) constant frequency (blue vector in inset) and uncorrelated phases. (See color plate.)... 

To determine color, we calculate the wavelength of each frequency and compare it with text Figure 9-3. 

Power Doppler sonography displays the amplitude of the Doppler signal but lacks the velocity and directional information present in frequency-based color Doppler sonography (10). However, power Doppler is more sensitive in the depiction of tumor vascularity (14-16), specifically within small tumor vessels (10,17). The hind limb tumor model and power Doppler can be utilized to measure the response of tumor blood vessels to radiation, providing longitudinal assessment of microvascular response within the same tumor without the need to section tumors for histology at various time intervals. 

Your heartbeat increases in frequency and amplitude as you gaze at her skirt, the color of cool mint. In the froth, space doesn t have a definite structure. It has various probabilities for different shapes and curvatures. It might have a 60 percent chance of being in one shape, a 20 percent chance of being in another, and a 20 percent chance of being in a third form. Because any structure is possible inside the froth, we can... 

The Electromagnetic Spectrum activity (eChapter 5.2) allows you to determine the frequency and wavelength of any color of visible light. 

However, the situation becomes already more complicated for ternary single crystals like lanthanum-aluminate (LaAlC>3, er = 23.4). The temperature dependence of the loss tangent depicted in Figure 5.3 exhibits a pronounced peak at about 70 K, which cannot be explained by phonon absorption. Typically, such peaks, which have also been observed at lower frequencies for quartz, can be explained by defect dipole relaxation. The most important relaxation processes with relevance for microwave absorption are local motion of ions on interstitial lattice positions giving rise to double well potentials with activation energies in the 50 to 100 meV range and color-center dipole relaxation with activation energies of about 5 meV. 

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