Radiation units table

TABLE 17.4 Property Radiation Units Unit name Symbol Definition... 

Fifteen -blockers have also been activated photochemically with the same radiation unit (Heraeus, Hanau Osram STE 501 UV lamp TNN 15-3200/721)[23]. Their detection limits, the working range and associated standard deviation of the method are listed in Table 1 below. The blue fluorescence of the chromatogram zones (Xg 5 = 313 nm, > 390 nm) was measured after dipping the chromatogram in liquid paraffin - n-hexane (1 + 2). Figure 18 illustrates the separation of seven P-blockers. 

The total heat loss is the sum of convection and radiation. From Table 1-2 we see that an estimate for the heat transfer coefficient for free convection with this geometry and air is h = 6.5 W/m2 °C. The surface area is ir d L, so the convection loss per unit length is... 

Table 3.3 summarizes the radiation exposure doses due to the industrial exploitation of phosphate rock, expressed in terms of collective effective dose equivalent commitments resulting from the decision to use a unit mass of marketable ore to accomplish a defined purpose, as reported by UN Scientific Committee on Effects of Atomic Radiation (United Nations, 1982). 

The defining event of a radioactive nuclide is the transformation of its nucleus into the nucleus of another species, that is, radioactive decay. The number of nuclear transformations occurring per unit of time is called activity . Sometimes radioactivity is used instead of activity . The traditional unit of activity has been the Curie (Ci), which is equal to 3.7 X 10 ° nuclear transformations per second. The conversion of radiation units to the international system (Sysfme International d Unit or SI) has now taken place in the United States. The more fundamental unit of activity, the Becquerel (Bq), equal to 1 nuclear transformation per second, has replaced the Curie. Both units of activity are modified by prefixes such as kilo-, milli-, and micro- to achieve standard multiples of the fundamental unit. A listing of the most commonly used prefixes is given in Table 1. 

Table 1 Standard multiples used with radiation units...

Note See Table 17.4 in the text for a list of the radiation units. 

Total radiation i the sum of the direct and scattered radiation that strikes the earth s surface. It is influenced by the degree of cloudiness, atmospheric transparency, duration of sunshine, and height of elevation at which the measurements are taken. Deviations from values in this table are bound to occur however, it is believed that the deviations do not exceed 10% for the summer months and 15% for the winter months. The radiation units in this table are kcal/cm . 

Table 19.5 shows the physical effects of short-term exposure to various doses of radiation, and Table 19.6 gives the sources and amounts of the radiation to which a typical person in the United States is exposed each year. Note that natural sources contribute about twice as much as human activities do to the total exposure. However, although the nuclear industry contributes only a small percentage of the total exposure, controversy surrounds nuclear power plants because of their potential for creating radiation hazards. These hazards arise mainly from two sources accidents allowing the release of radioactive materials, and improper disposal of the radioactive products in spent fuel elements. 

Table 10-1. Practical Relationships among Radiation Units...

Knowing how many disintegrations per unit time occur in a radioactive sample, or the number of ionizations in a volume of air, are not very helpful in characterizing the effects of radiation on human tissue and therefore the rad and the rem are commonly used to measure radiation dosage. Table 10-4 lists the types of radiation units, and the situations in which they are appropriately applied. A rad of a-rays will produce more damage than a rad of /3-rays. 

Polynucleotide Strand-Analogues The following polymers (Tables I and II) were prepared by AIBN- or -ray induced (Laboratory Radiation Unit RCH-y-30 as a 60co -source) polymerization and copolymerization reactions, respectively, followed in case of (vA, IvOH]q 7)p by a polymeranalogous reaction. The starting amounts of N-vinylnucleobases and their comonomers were adjusted to yield a nearly l l-ratio in the copolymers. 

To provide for representative sampling, specific procedures for sampling have been suggested by the International Commission on Radiation Units and Measurements (ICRU) [32]. Although this may not eliminate the uncertainty associated with activity levels in environmental samples, it may reduce the uncertainty and enable it to be quantified by statistical means. Table 5 summarizes the main sampling techniques [32] and their features. 

Intensity of UV radiation is measured in radiometric units (Tables 10.1,10.2), whereas the intensity of visible light is measured in photometric units (Table 10.1) by radiometers [1762] ... 

Table 1 depicts the main light sources used in artificial weathering tests and their characteristic wavelengths. Table 2 shows typical photochemical terms and their corresponding measurement units. Table 3 gives a detailed global radiation spectral distribution. 

One unit long used to describe exposure to radiation is the rad. One rad (radiation Absorbed dose) corresponds to the absorption of 1 X 10 J of energy per kilogram of matter. The effect of a dose of one rad on living matter is variable, however, and a better unit is one that takes this variability into account. The rem (radiation equivalent for man) is the rad multiplied by the relative biological ejfectiveness (Q). The factor Q takes into account that equal doses of radiation of different types may have differing effects. Table 25.5 summarizes several radiation units. 

Using QMOBAS, TMOBAS, or Mathcad and the method from Computer Project 6-2, calculate the energy separation between the HOMO and LUMO in units of p for all compounds in Table 6-1 and enter the results in Table 6-2. Enter the observed energy of ultraviolet radiation absorbed for each compound in units of cm . The reciprocal wavelength is often used as a spectroscopic unit of energy. 

Section 13 20 IR spectroscopy probes molecular structure by examining transitions between vibrational energy levels using electromagnetic radiation m the 625-4000 cm range The presence or absence of a peak at a charac tenstic frequency tells us whether a certain functional group is present Table 13 4 lists IR absorption frequencies for common structural units... 

Table 22. Daily Solar Radiation in the United States ...

The surface-emissive power E, the radiation per unit time emitted per unit area of fireball surface, can be assumed to be equal to the emissive powers measured in full-scale BLEVE experiments by British Gas (Johnson et al. 1990). These entailed the release of 1000 and 2(XK) kg of butane and propane at 7.5 and IS bar. Test results revealed average surface-emissive powers of 320 to 370 kW/m see Table 6.2. A value of 350 kW/m seems to be a reasonable value to assume for BLEVEs for most hydrocarbons involving a vapor mass of 1000 kg or more. 

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