Radiation rate

Furnaces for Oil and Natural Gas Firing. Natural gas furnaces are relatively small in size because of the ease of mixing the fuel and the air, hence the relatively rapid combustion of gas. Oil also bums rapidly with a luminous flame. To prevent excessive metal wall temperatures resulting from high radiation rates, oil-fired furnaces are designed slightly larger in size than gas-fired units in order to reduce the heat absorption rates. 

Convert the readings in Data Table 2 to a count rate in cpm by multiplying them by 2. Subtract the background radiation rate obtained in step 2 from each count rate to obtain the corrected count rate. 

Sample Designation Radiation Rate, Mrads/sec. Total Radiation Dosage, Mrads... 

The half-life (Eq. 9-4) determines the isotopic abundance needed to achieve a given radiation rate, a practical matter in providing a sufficient rate of decay to permit counting with an acceptably low statistical error. Even very short-lived isotopes such as 13N, have proved useful as tracers.13 The amount of an isotope giving 3.7 x 1010 disintegrations per second (this is 1 g of pure radium, 0.3 mg of 3H, or 0.22 g of 14C) is known as the curie (Ci). One milli-curie (mCi) provides 2.22 x 109 disintegrations / min... 

The discriminator produces an output pulse with a fixed shape (generally square) and size when the input signal crosses a reference. Discriminators usually have multiple identical output signals. The logic pulses can be sent to a scaler that simply counts the number of pulses, to a count rate meter to monitor radiation rates or doses, and to a time-to-amplitude converter (TAC) to measure the relative times of arrival of two or more logic signals. 

An analysis of the solar distillation process shows that performance is remarkably insensitive to all variables except solar radiation rate. As atmospheric temperature changes, basin and cover temperatures move similarly, so that their difference remains... 

Qsh = net solar radiation rate absorbed on basin bottom, B.t.u., sq. ft., day (equals incident radiation minus reflection from cover, salt water surface, and basin bottom)... 

In the lower left corner, zone (arrowed) of the cross section of an Ag,S stained PA 66 fiber, which is responsible for crystalline pattern I. Numbers I, 2, and 3 are three successive exposures of the same pattern with an equal radiation rate—notice progressive fading of the outer, less intense (010) arc A amorphous pattern (photographed in the same conditions) corresponding to the same area. 

Assuming the sum of the radiationless and radiational rate constants between levels 3 and 2 for inorganic probe, like T1, are much less than the non-radiational mixing constant k2i, then the 2-level expression relating 1/Bp to 1/E applies. Using this relationship and the following measured parameters slit area,... 

Beltran FJ. Estimation of the relative importance of free radical oxidation and direct ozonation/UV radiation rates of micropollutants in water. Ozone Sci Eng 1999 21 207-228. 

Nuclei with Atomic Number Greater Than 83 Detection of Radiation Rates of Decay and Half-Life Disintegration Series Uses of Radionuclides Artificial Transmutations of Elements Nuclear Fission Nuclear Fission Reactors Nuclear Fusion... 

In this case we have linearized the radiation rate equation, making the heat rate proportional to a temperature difference rather than to the difference between two temperatures to the fourth power. Note, however, that hr depends strongly on temperature, while the temperature dependence of the convection heat transfer coefficient, h is generally weak. 

Solution to Example 3.4 For parallel planes, third case on p. 97 of reference 51, find the emissivity factor, Fe, to use with an arrangement factor of Fa = 1.0 in formula 4/la on p. 81 and with a black body radiation rate from the table on page 82, as follows ... 

For 1600 F tube temperature and 1100 F load temperature, find that the black body radiation rate is 20 700 Btu/ft hr. 

In table 8.7, enter the difference between the black body radiation rate for furnace temperature [b] and load temperature [d], on line [i]. Multiply [i] by 3H, for the 3 unit group, and enter the resulting Btu/pound heat content rise of the load on line j]. The Shannon method s H factor reduces black body radiation by the effect of emis-sivity (absorptivity). In succeeding columns, use line [k] to totalize the cumulative Btu/pound. In figure 8.9, convert the new Btu/pound heat content to a new average temperature throughout the load (270 F for the first three time units), and record it on line [1],... 

The van der Waals interaction as described above can be interpreted as an effect caused by the modification of the boundary conditions imposed on the electromagnetic field around the atom. This affects the level width as well as its position the radiation rate is proportional to the density of vacuum modes which in turn depend on the boundary. Thus, an excited atom connected to lower states by an E1 transition moment parallel to the metallic surface will have its radiation rate reduced. If the distance d to the surface is less than X the rate is given approximately by... 

Since a resonant cavity can enhance spontaneous emission, it is not surprising that a nonresonant cavity can depress it. Consider for instance a cavity whose fundamental frequency is at twice the resonant frequency of the atomic transition. In this case, the radiation rate becomes... 

It is important to realize that a cavity is not absolutely necessary to modify the spontaneous decay rate of an atom. Any conducting surface placed near it will affect the mode density and hence its decay rate. For instance, parallel conducting plates can somewhat alter the mission rate, but at most reduce it by a factor of 2 because of the existence of TEM modes, which are independent of the separation. The effect of conducting surfaces on the radiation rate has been studied theoretically in a number of investigations (for details see Reference [1]). 

Many systems have also been developed and tested in Europe. The setup of all the systems was very similar. As an example of all stationary systems implemented, the regenerative PHOEBUS system at Forschungszentrum Jiilich will be described in detail. The idea was to store the surplus electrical energy produced by a solar field on the library building in the summer months for use in winter when radiation rates are lower (Figures 8.15 and 8.16). 

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