Conversion coefficients equivalent

In order to compare exposures to radon decay-products with those to other forms of ionising radiation, it is useful to assess the effective dose equivalent expressed in sieverts (Sv). A conversion coefficient of 15 Sv per J h m"3, equivalent to 5.5 mSv per WLM, has been recommended (UNSCEAR, 1982). With this conversion factor, the... 

On the basis of a conversion coefficient of 5.5 mSv WLM"1, occupants of the vast majority of dwellings in the UK receive annual effective dose equivalents less than 2 mSv. Even in the areas surveyed because of their potential for high radon exposures, the annual effective dose equivalents are unlikely to exceed a few tens of mSv. However, in certain areas of Cornwall and Devon, annual effective dose equivalents higher than 25 mSv may be received in a small percentage of dwellings. In some dwellings more than 50 mSv per year may be received. 

It is noted that the ICRP has assumed a higher conversion coefficient between annual effective dose equivalent and radon concentration (ICRP, 1984) in recommending an action level for remedial measures in homes, i.e. 1 mSv y"1 per 10 Bq m"3 of equilibrium equivalent radon gas concentration (9 mSv per WLM). If this conversion coefficient were applied to our regional survey data, we would estimate, from the distribution parameters given in table 3, that about 15% of the residents of certain areas of Devon and... 

Calibration of the intensities of the radiation flelds is traceable to the NIST. The ionization chambers and electrometers used by the service laboratories to quantify the intensity of the radiation fields must be calibrated by the NIST or an accredited secondary standards laboratory. The intensity of the field is assessed in terms of air kerma or exposure (free-in-air), with the field collimated to minimize unwanted scatter. Conversion coefficients relate the air kerma or exposure (free-in-air) to the dose equivalent at a specified depth in a material of specified geometry and composition when the material is placed in the radiation field. The conversion coefficients vary as a function of photon energy, angle of incidence, and size and shape of backscatter mediiun. 

Figure 3.1 reproduces the conversion coefficients provided in ICRU (1988) for FrE/[ 3fp(10)]. For these conversion coefficients, i p(10) was approximated by the dose equivalent at a depth 10 mm along an appropriate radius (i.e., the central axis) in the ICRU sphere (ICRU, 1988). Conversion coefficients are given for personal monitors located on the body at the center of the chest (i.e., the front) or the center of the back (i.e., the back) for the following irradiation geometries ... 

The 130 keV State. The decay of the 130 keV state has been studied extensively, and several inconsistencies are being resolved. The results of different measurements of the mean life and decay mode of the 130 keV state are discussed by Fink and Benczer-Koller (8). The half-life of the state has been measured electronically, and the transition matrix element for excitation has been derived from Coulomb excitation data (12). The combination of the Coulomb excitation yield, the internal conversion coefficient (8) a = 1.76 =t= 0.19, and the branching ratio (8) PCo = 0.060 zb 0.008 for the crossover decay to ground, yields a half-life ti/2 = (0.414 0.014) ns in excellent agreement with a recent (15) Mossbauer determination of the line width, r = (4.4 zb 0.4) mm/sec, equivalent to t1/2 = (0.49 0.05) ns. Wilenzick et al. (15) do not indicate the thickness of the Pt absorber used. 

The conversion between equivalent pipe length and the resistance coefficient, K, can be expressed as ... 

The variation in the second-order rate coefficients with time and with change in initial concentration of mercuric salt can also be explained on the basis of equilibria (213) and (214). At low acidities, conversion of mercuric acetate to acetoxymercury perchlorate is incomplete, and, therefore, decreasing the concentration of the acetate increases the concentration of free perchloric acid which thus increases the conversion of the acetate into the more reactive perchlorate, hence the second-order rate coefficients increase. Decreasing the concentration of mercuric perchlorate will, however, decrease the concentration of free perchloric acid and this effect will be particularly marked since solvation of the perchlorate produces two equivalents of perchloric acid the second-order rate coefficients will, therefore, decrease. In both cases, substitution changes the concentration... 

Batch operation For the design of batch reactors for biphasic conversion the type of stirring device is an essential aspect to generate a narrow distribution with small droplet sizes which is equivalent to high surfaces [36]. Together with the diffusion ability (diffusion coefficient) of the used sol-... 

All authors, for instance, consider the jacket oil at constant temperature. This assumption, equivalent to that of infinite oil flow rate, makes it impossible to correctly compute the overall heat transfer coefficient and the thermal driving force. Since heat exchange plays an important role in the conduction of industrial reactors, where more than one third of the polymerization heat is removed through the external cooling oil (only very low conversion reactors can be assumed adiabatic, as claimed by Chen et al.), this limitation cannot be accepted. 

Here x is the conversion of SiH4. combines the effect of the molar expansion in the deposition process as well as the change in the volumetric flow and the dispersion coefficient, D, with temperature. At low pressures and small Re in LPCVD reactors the dispersion occurs mainly by molecular diffusion, therefore, we have used (D/D0) = (T/T0)l 65. e is the expansion coefficient and the stoichiometry implies that e = (xi)q, the entrance mole fraction of SiH4. The expansion coefficient, e is introduced as originally described by Levenspiel (33) The two reaction terms refer to the deposition on the reactor wall and wafer carrier and that on the wafers, respectively. The remaining quantities in these equations and the following ones are defined at the end of the paper. The boundary conditions are equivalent to the well known Danckwerts1 boundary conditions for fixed bed reactor models. 

Calibration curve parameters for original and converted data are shown in Table 20.7 the values are equivalent. However, the criteria chosen for acceptance of the data migration were based on the calculated results. As the analysis is based upon a comparative method of analysis (chromatography), the results were deemed the best way of evaluating if the conversion was successful. The key question is, would the same decision be taken on the data Therefore, a regression line of the MassChrom vs. the Analyst across all concentrations should have a correlation coefficient elose to 1 if the results were the same by both methods. These data are shown in Figure 20.10. 

A good way to determine the rate coefficients klP and k2Q from experimental results is first to find k from the slope of a first-order plot for the respective reactant or an equivalent numerical method, then to calculate ki and k2Q from it, the isomerization equilibrium constant KI2, and the product concentrations at complete conversion ... 

Development of the W — fN H relation, the CoG, beyond the weak-line limit depends on the profile of the absorption coefficient <)>(AA). An extreme form for the profile is effective at illustrating this point. Suppose (AA) = a for AA = AXD and 0 for AA > AAj> Normalization of provides the relation connecting the constant a, the width AXd, and the /-value - the derivation is left as an exercise for the student With increasing fN H, I(AX)/Iq falls within the line to its minimum value of zero. At which point, the equivalent width has saturated at W = 2AAd- Note that, unlike W in the weak-line limit, the CoG beyond the weak-line portion depends on the shape of the line absorption coefficient - here, the width AAd. This dependence means that conversion of a measured W to JNlH for realistic absorption coefficient profiles demands observational or theoretical knowledge of the absorption coefficient s profile. This requirement plus the reduced sensitivity of W to /NlH make this part of the CoG less attractive for abundance determinations. This stretch of the CoG is variously referred to as the flat, Doppler or saturated part. 

Here, ay is the thermal expansion coefficient which is assumed to be equal in both lattices and 6 is the dilatation coefficient (Khs — ls)/ ls> where Fls and Fhs are the unit cell volumes of the pure LS and HS species at 0 K, respectively. In order to account for the anisotropy of the lattice, the thermal expansion v and dilatation e coefficients must be introduced as tensors instead of scalars. Similarly, an equivalent expression could be defined for pressure-induced spin conversions. 

SPHERICITY is the ratio of the surface area of a sphere having the same volume as the particle, to the actual particle surface area the reciprocal is known as the coefficient of rugosity or angularity. It can be shown that sphericity is also equal to the ratio of the surface-volume diameter to the equivalent volume diameter this makes sphericity a useful conversion factor between... 

To start, we note that the short time Kst(T ) and Grote-Hynes kgh(T ) transmission coefficients are algebraically equivalent [23]. However, Kst(T) and Kgh(T ) are useful expressions in different physical regimes. Eqs. (3.50) and (3.51) for Kst(T) provide a useful parameterization of k(T ) only for reactions for which the rate constant k T) is determined by short time dynamics while Eqs. (3.46) and (3.47) provide a useful parameterization only for reactions for which k T) is determined by slow variable dynamics. Nearly equivalently, Eqs. (3.50) and (3.51) apply to sharp barrier reactions, where the sharp barrier limit is defined as comip oc while Eqs. (3.46) and (3.47) apply to flat barrier reactions, where the flat barrier limit is defined as (Ormf 0. (The sharp barrier limit is taken as comip oo, not as PMF oc as in Section III.B, isasmuch as sharp barrier reactions are short time, high-frequency processes for which oomip is the physical barrier frequency. The converse argument yields the flat barrier limit as copmf 0.)... 

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