Percent incident radiation absorbed

To obtain a parameter relative to the Intensity incident on the surface of the coating, we define PIA as the percent of incident radiation absorbed ... 

Figure 3 - The influence of optical density of a coating on the percent of incident radiation absorbed at various depths (monochromatic radiation).

The absorbed radiation In a given segment was summed over all wavelengths to determine the total percent of incident radiation absorbed in each segment. Plots of PIA vs. depth will be utilized in the discussions below. By convention, PIA calculated at depth -... 

Figure 4 - Percent of Incident radiation absorbed at various depths In a coating containing concentrations of CGI-369 ranging from 0.5 to 7.5% (Fusion H bulb radiation).

An infrared spectrum is a plot of percent radiation absorbed versus the frequency of the incident radiation given in wavenumbers (cm ) or in wave length ( xm). A variation of this method, diffuse reflectance spectroscopy, is used for samples with poor transmittance, e.g. cubic hematite crystals. Increased resolution and sensitivity as well as more rapid collection of data is provided by Fourier-transform-IR (FTIR), which averages a large number of spectra. Another IR technique makes use of attenuated total reflectance FTIR (ATR-FTIR) often using a cylindrical internal reflectance cell (CIR) (e.g. Tejedor-Tejedor Anderson, 1986). ATR enables wet systems and adsorbing species to be studied in situ. 

Part of the solar radiation entering the earth s atmosphere is scattered and absorbed by air and water vapor molecules, dust particles, and water droplets in the clouds, and thus the solar radiation incident on earth s surface is less than tlie solar couslanl. The extent of the attenuation of solar radiation depends on the length of the path of the rays through the atmosphere as well as the composition of the atmosphere (the cloud.s, dust, humidity, and smog) along the path. Most ultraviolet radiation is absorbed by the ozone in the upper atmosphere. At a solar altitude of 41.8°, the total energy of direct solar radiation incident at sea level on a clear day consists of about 3 percent ultraviolet, 38 percent visible, and 59 percent infrared radiation. 

Figure 24-7 depicts the attenuation of a parallel beam of monochromatic radiation as it passes through an absorbing solution of thickness b centimeters and concentration c moles per liter. Because of interactions between the photons and absorbing particles (recall Figure 24-5), the radiant power of the beam decreases from Pq to P- The transmittance T of the solution is the fraction of incident radiation transmitted by the solution, as shown in Equation 24-4. Transmittance is often expressed as a percentage called the percent transmittance. 

Thus, if a transition exists which is related to the frequency of the incident radiation by Planck s constant (h = 6.626-1 O 34), then the radiation can be absorbed. Conversely, if the frequency (v) does not satisfy Planck s expression, then the radiation will be transmitted. A plot of the frequency of the incident radiation against some measure of the percent radiation absorbed by the sample provides the absorption spectrum of the compound or component. The absorption spectrum is characteristic for the compound and this spectrum is often called the fingerprint of the compound. Infrared spectroscopy is based on the measurement of the absorption of electromagnetic radiation that arises from the altering of the vibration level of the component s molecule. An example of the adsorption and transmission of the infrared radiation is shown in Figure 2.30. 

Alternatively, the FLC can be doped by some percent of a didiroic dye. If the incident radiation power is absorbed more dir y by the dye molecules or the pyroelectric material itself (IR absorption bands), a slower thermal relaxatioo can be expected. As the thermal rclaxatioo time depends in a complicated way on a numbo of factors such as cell geometry, light-absorbing laya, and thermal conducting coefficients, carefiil design has In be chosen to produce a device possessing a thermal iclaxatinn as slow as possSde. 

About 51 percent of solar energy incident at the top of the atmosphere reaches Earth s surface. Energetic solar ultraviolet radiation affects the chemistry of the atmosphere, especially the stratosphere where, through a series of photochemical reactions, it is responsible for the creation of ozone (O,). Ozone in the stratosphere absorbs most of the short-wave solar ultraviolet (UV) radiation, and some long-wave infrared radiation. Water vapor and carbon dioxide in the troposphere also absorb infrared radiation. 

Euphotic Of the depth zone through which light penetrates. The bottom of the euphotic zone is defined as the depth at which less than 1 percent of the incident solar radiation remains, the rest having been either absorbed or reflected. 

Analysis The absorptivity of the plate is 0.6, and thus 60 percent of the solar radiation Incident on the plate is absorbed continuously. As a result, the temperature of Ihe plate rises, and the temperature difference between the plate and the surroundings increases. This increasing temperature difference causes the rate of heat loss from the plate to the surroundings to increase. At some point, the rate of heat loss from the plate equals the rate of solar... 

When solar radiation strikes a glass surface, part of it (about 8 percent for uricoatcd clear glass) is reflected back to outdoors, part of it (5 to 50 percent, depending on composition and thickness) is absorbed within the glass, and the remainder i.s transmitted indoors, as shown in Fig. 12-48. The conservation of energy principle requires that the sum of the transmitted, reflected, and absorbed solar radiations be equal to the incident solar radiation. That is,... 

Eye Absorption of UV radiation by the cornea (that absorbs most of the UV-B) and by the lens the UV radiation rarely reaches the retina of the eye. However, acute short-term exposure of the eye to UV-B radiation can lead to increased incidence of eye decease ranging from simple snow blindness (photokeratitis) to squamous cell carcinoma (SCC). Strongest correlation between eye diseases and exposure to solar radiation is observed for the condition pterigyium and climatic droplet keratopathy. With SCC, a recent epidemiological study found a strong relationship between the incidence of the disease and the latitude of exposure [2] (with 40-50 percent increase in incidence per 10° change in latitude). 

A blackbody is an idealized object that absorbs 100 percent of the radiation that is incident upon it. No real object is a perfect blackbody. 

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