Radiation intensities

Gibbs free energy or Gibbs molar free energy molar flow of gas phase acceleration of gravity enthalpy, molar enthalpy, weight enthalpy Henry s constant Planck s constant height horsepower radiation intensity molar flux... 

Induction electron accelerators - betatrons- are widely used as radiation sources in industrial flaw detection of materials and articles of high thickness. However, relatively low radiation intensity has become the barrier for the most wider betatron use in this area. For the efficiencyincrease of radiation control method of articles, as well as for the possibility to control materials and articles of the most thickness the significant increase of betatron radiation intensity has been required. 

The MCB tubes suit ideally into a concept of using glass capillary X-ray light guides to increase radiation intensity at the measurement spot. 

In thermoluminescence dating, a sample of the material is heated, and the light emitted by the sample as a result of the de-excitations of the electrons or holes that are freed from the traps at luminescence centers is measured providing a measure of the trap population density. This signal is compared with one obtained from the same sample after a laboratory irradiation of known dose. The annual dose rate for the clay is calculated from determined concentrations of radioisotopes in the material and assumed or measured environmental radiation intensities. 

Fig. 5. Effect of uv exposure on nylon-6,6 yam tenacity and whiteness with and without copper salt and alkah haUde in polymer scoured 210-denier 34-filament yams exposed in Xenon-arc Ci65 Weather-Ometer using radiation intensity of 0.55 W/m at a wavelength of 340 nm. Exposure from 0 to 800...

Wind speed, m/s Day radiation intensity Night cloud cover ... 

The sun radiates approximately as a blackbody, with an effective temperature of about 6000 K. The total solar flux is 3.9 x 10 W. Using Wien s law, it has been found that the frequency of maximum solar radiation intensity is 6.3 x 10 s (X = 0.48 /rm), which is in the visible part of the spectrum 99% of solar radiation occurs between the frequencies of 7.5 X 10 s (X = 4/um) and 2 x 10 s (X = 0.15/um) and about 50% in the visible region between 4.3 x 10 s (X = 0.7 /rm) and 7.5 X 10 s (X = 0.4 /Ltm). The intensity of this energy flux at the distance of the earth is about 1400 W m on an area normal to a beam of solar radiation. This value is called the solar constant. Due to the eccentricity of the earth s orbit as it revolves around the sun once a year, the earth is closer to the sun in January (perihelion) than in July (aphelion). This results in about a 7% difference in radiant flux at the outer limits of the atmosphere between these two times. 

Total heat transfer consists of radiation at different frequencies. The distribution of radiation energy in a spectrum and its dependency on temperature is determined from Planck s law of radiation. M ,and are the spectral radiation intensities for a blackbody ... 

When these are derived with respect to the wavelength, and the wavelength value, whth the maximum value of radiation intensity, is solved for, the tesuh is Wien s law ... 

FIGURE 4.29 Radiation intensity of a blackbody as a function of wavelength (tennperature parameter). 

The visibility factor of the surface element ip,y depends on the geometry and gives that part of the radiation intensity of dAy that falls directly on the surface dA, or vice versa. 

Tlie radiation intensity of a surface element is the sum of emission and reflectioti ... 

In the preceding formula, denotes the intensity absorbed from the excitation radiation (intensity /g). This absorbed intensity generates fluorescent radiation and other reactions. 

An instrument for measuring nitrogen oxides based on chemiluminescence is shown in Fig. 13.49. The ozone required for the reaction is produced in the ozone generator, which is part of rhe device. One of the reaction chamber walls is an optical filter through which a red-sensitive photomultiplier tube measures the chemiluminescence radiation intensity and converts it into a current signal. 

Photodiodes produce an electric field as a result of pn transitions. On illumination a photocurrent flows that is strictly proportional to the radiation intensity. Photodiodes are sensitive and free from inertia. They are, thus, suitable for rapid measurement [1, 59] they have, therefore, been employed for the construction of diode array detectors. 

However, the optical train illustrated in Figure 22B allows the determination of fluorescence quenching. The interfering effect described above now becomes the major effect and determines the result obtained. For this purpose the deuterium lamp is replaced by a mercury vapor lamp, whose short-wavelength emission line (2 = 254 nm) excites the luminescence indicator in the layer. Since the radiation intensity is now much greater than was the case for the deuterium lamp, the fluorescence emitted by the indicator is also much more intense and is, thus, readily measured. 

Radiation Intensity (Btuihrlffi) (kWIm ) Time to Reach Pain Threshold (s)... 

Thermal effects depend on radiation intensity and duration of radiation exposure. American Petroleum Institute s Recommended Practice 521 (1982) reviews the effects of thermal radiation on people. In Table 6.5, data on time to reach pain threshold are given. As a point of comparison, the solar radiation intensity on a clear, hot summer day is about 1 kW/m (317 Btu/hr/ft ). Criteria for thermal damage are shown in Table 6.6 (CCPS, 1989) and Figure 6.10 (Hymes 1983). 

Eisenberg et al. (1975) developed estimates of fatalities due to thermal radiation damage using data and correlations from nuclear weapons testing. The probability of fatality was found to be generally proportional to the product where t is the radiation duration and 7 is the radiation intensity. Table 6.7 shows the data used to develop estimates of fatalities from thermal radiation data. 

Probability of Fatality (%) Duration, t (sec) Radiation Intensity, 1 (kW/m ) Dosage, tl lsec(k Nlrri ) ]... 

The thermal radiation intensity of a flash fire can be calculated after parameters such as cloud shape and gas or vapor concentration distribution have been determined through dispersion calculations. Subsequently, the thermal radiation intensity is calculated through the following steps ... 

Fireballs radiate intense heat, wliich can cause fatal bums and can quickly ignite otlier materials. Tlie diameter and persistence time of the fireballs can be calculated by tlie equations developed by Gayle and Bransford. ... 

The tlienual radiation intensity and tlie time duration of fires often are used to estimate injury and damage due to a fire. Various tables liave been compiled to set up criteria for fire damage to people and property. Table 7,3.1 shows a relationsliip between heat radiation intensity and bum injury, ... 

The flame behavior of a fire is important in determining tlie causes and effects of fires. There are several classificiitions of flames orifice flames, pool flames, fireballs. Jet fimnes, and flash fires. Orifice or pipe flames are characterized as eitlier prenii. ed flame or diffusion flmiies. Pool flames are flames on ground pools and flames on tanks. Fireballs radiate intense heat, wliich can cause fatal bums and can quickly ignite otlier materials. Jet flame or flares also radiate intense heat. 

Figure 7-75. Heat radiation intensity vs. exposure time for bare skin at the threshold of pain. By permission, Kent, Hydrocarbon Processing, V. 43, No. 8 (1964), p. 121 [60].

---