Weighted average rating

Equations (9.120) and (9.121) illustrate that the effectiveness factor represents the ratio between a weighted average rate and the rate that would be obtained, if the conditions were similar to those in the bulk phase. If no concentration gradients emerge in the particle, r, in eq.(9.120) can be replaced with a constant, n (cb), and the integration of (9.120) gives the effectiveness factor, rj, =1. 

Step 1 Select Portfolio. Select a target portfoHo of assets that meet defined criteria for spread, and weighted average rating factor (WARE). 

In the above example, the discount rate used was the annual compound interest rate offered by the bank. In business investment opportunities the appropriate discount rate is the cost of capital to the company. This may be calculated in different ways, but should always reflect how much it costs the oil company to borrow the money which it uses to invest in its projects. This may be a weighted average of the cost of the share capital and loan capital of a company. 

Phosphine has an 8-h time-weighted average exposure limit of 0.3 ppm (13). Under alkaline conditions the rate of PH formation is high. At neutral or acidic pH, the PH generation is slow but stiU very ha2ardous if the PH is allowed to accumulate in a confined vapor space. The safest commercial handling conditions for molten phosphoms are generally considered to be from pH 6 to 8 at 45—65°C. 

Another economically driven objective is to utilize initiators that increase the rate of styrene polymerization to form PS having the desired molecular weight. The commercial weight average molecular weight M range for general-purpose PS is 200,000—400,000. For spontaneous polymerization, the is inversely proportional to polymerization rate (Fig. 16). 

Lumped mechanisms are based on the grouping of chemical compounds into classes of similar stmcture and reactivity. For example, all alkanes might be lumped into a single class, the reaction rates and products of which are based on a weighted average of the properties of all the alkanes present. For example, as shown in Table 1, the various alkanes, CH2 2 > react with OH in a similar manner to form alkyl radicals,. When expressed... 

Typical of thermoplastics (see Chapter 8) the melts are pseudoplastic and also in common with most thermoplastics the zero shear rate apparent viscosity of linear polyethylene is related to the weight average molecular weight by the relationship... 

Fig. 31. Evolution of the T-peel strength of roughened styrene-butadiene rubber/polychloro-prene-aromatic hydrocarbon resin blends as a function of the weight average molecular weight of the hydrocarbon resin. Peeling rate = 10 cm/min.

The metabolic rate can be estimated by ISO EN 9886, and the thermal resistance of clothing can be estimated by ISO EN 9920, taking into account the type of work and the time of year. For varying metabolic rates, it is recommended to estimate a time-weighted average during the previous 1 h period. For sedentary people, the insulation of a chair must also be taken into account. 

FIGURE 16.24 Inulin isolated from mature Topinambur tubers sparated on Bio-Gel P-6 (140 X I. Scm) flow rate 0.33 ml/min eluent H20(dest) + 0.002% NaNs detection Waters 403 R differential refractive index detector, sensitivity 8X applied sample I ml of a 20-mg/ml aqueous solution weight average degree of polymerization dp = 9 number average degree op polymerization dp = 2 polydisper-sity dp /dp = 4.5. 

Required revenues are the sum of operation and maintenance expenses, depreciation, taxes, and a return on rate base. The rate base is the total amount of fixed capital used by the utility in producing, transmitting, and delivering electricity. The return on rate base IS the weighted average cost of capital, including debt and equity sources. 

Most in depth studies of termination deal only with the low conversion regime. Logic dictates that simple center of mass diffusion and overall chain movement by reptation or many other mechanisms will be chain length dependent. At any instant, the overall rate coefficient for termination can be expressed as a weighted average of individual chain length dependent rate coefficients (eq. 20) 39... 

This, in turn, reduced the number of polymer particles (the loci of reaction) and hence the reaction rate fell. However, this explanation is at variance with the results reported in Figure 12 where the molecular weight (weight-average) clearly increases with increasing Reynolds number. It seems more likely that the turbulent flow results could be explained by a decrease in the effective initiator concentration. This low concentration would also explain why there is no further reaction after a period of about one hour as contrasted with the batch reactions where the reaction is still proceeding after two to three hours. The current absence of corroborating evidence makes this explanation very tentative. 

Figure 1 Is a flow sheet showing some significant aspects of the Iterative analysis. The first step In the program Is to Input data for about 50 physical, chemical and kinetic properties of the reactants. Each loop of this analysis Is conducted at a specified solution temperature T K. Some of the variables computed In each loop are the monomer conversion, polymer concentration, monomer and polymer volume fractions, effective polymer molecular weight, cumulative number average molecular weight, cumulative weight average molecular weight, solution viscosity, polymerization rate, ratio of polymerization rates between the current and previous steps, the total pressure and the partial pressures of the monomer, the solvent, and the nitrogen.

Concentrations of the monomer, solvent, polymer, and initiator Solution viscosity Number average polymer mol. wt. Weight average polymer mol. wt. Polymerization Rate Reaction time Heat generated Heat losses Solution Temperature Partial pressures of the monomer, solvent, and nitrogen Total pressure... 

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