Drop number

To obtain updated listing of the published information on this research, contact the AIChE office in New York. The work is original and conducted by thoroughly qualified researchers/engineers. The work on runaway reactions is the first systematized examination of the subject and is really the only design approach available, but it requires careful study and is notjust dropping numbers in equations. 

After allowing the emulsion to stand for a time the drop number was taken, the assumption being made that the oil globules would have no effect. The figures were —... 

The experiment was therefore varied by allowing the oil to rise through the solution in very fine drops of definite size. The change in concentration was again measured by taking the drop number before and after treatment with a known number of drops. The principle of this altered method will be easily understood from a description of the apparatus used in a third series of experiments, in which mercury in the form of fine drops was used as the adsorbent (Fig. io). 

The right-hand side was derived from the variation of the drops number considering the volume conservation principle. From Eq. (5.12), the authors deduce an estimation of the frequency oj valid for Ds D and some values are reported in Table 5.1. 

Instead of measuring the weight directly we may calculate it from the volume and the density the drop volume method has been applied by Harkins chiefly to the measurement of the tension between two liquid phases, and it probably falls little short in accuracy from the previous method. More frequently it has been j modified, especially for biochemical purposes, as a drop number method that is, a known volume of liquid iFallbwed oo nov. of a tube, and the number of drops formed is compared with that formed by a standard fluid. This method is necessarily very rough. 

The soaps are in all probability not produced during emulsification by hydrolysis of the glycerides but from impurities present in the oils, since olive oil may be prepared in sufficient purity as not to be affected by the addition of caustic soda the following figures being obtained by Donnan (Zeit. Phys. Ghem. XXXI. 42,1899) for the drop numbers of purified and ordinary olive oil in water and caustic soda. 

Effect of aerosol particles on cloud drop number concentrations and size distributions Clouds and fogs are characterized by their droplet size distribution as well as their liquid water content. Fog droplets typically have radii in the range from a few /an to 30-40 /an and liquid water contents in the range of 0.05-0.1 g m" Clouds generally have droplet radii from 5 /an up to 100 /im, with typical liquid water contents of 0.05-2.5 gin"5 (e.g., see Stephens, 1978, 1979). For a description of cloud types, mechanisms of formation, and characteristics, see Wallace and Hobbs (1977), Pruppacher (1986), Cotton and Anthes (1989), Heyms-field (1993), and Pruppacher and Klett (1997). 

Fig. 8. Elution curves for carrier-free actinides (An), Nb, Ta, and Pa from TiOA/Voltalef columns (1.6x8 mm) under the same conditions as in the dubnium experiments. The horizontal error bars are associated with uncertainties in converting drop numbers into effluent volumes, i.e., times. In the upper part, the 262Db is sorbed on the column from a) 12 M HC1/0.02 M HF, b) 10 M HC1, and is stripped along with the TiOA from the column in acetone/0.02 M HF. In the middle part, the activity is extracted as in a), followed by separate elutions of a Nb,Pa fraction, and a Ta fraction. In the lower part, the activity is extracted as in b), followed by a Pa, and then a Nb fraction. The number of 262Db decays observed in a given fraction is given in the text. Reproduced from [42] with the permission of Oldenbourg Verlag.

Chorge Cook-Off Velocity, Drop Number Exploded... 

Charge Density., Cook-Off Temp A354 Deten Veloc ity, m/sec Wox-Gop, Impact-Friction Pendu Drop Number Exp < Height, to Totol Sami ... 

From the foregoing considerations it will be apparent that the lower the surface tension at the oil/water interface, the smaller will be the size of the drops of oil formed in an emulsion. Donnan s drop-number method is a simple and convenient means of determining or comparing oil/detergent solution interfacial surface tension. The apparatus is shown in Fig. 9.12, in which a pipette A of about 5 ml capacity is provided with a capillary tube B... 

The incremental pressure drop number K(x) in the hydrodynamic entrance region is expressed as... 

The relationship between the friction factor, axial pressure drop, and incremental pressure drop number is the following ... 

Solutions for the Flow with Re < 400. It has been found that the effects of axial momentum diffusion and radial pressure variation are significant only in the duct inlet of x < 0.005. Chen [11] obtained the dimensionless hydrodynamic entrance length L y and the fully developed incremental pressure drop number K(< >), which are given by... 

The fully developed incremental pressure drop number K(°°) for elliptic ducts has been found to be independent of the duct aspect ratio a = 2bl2a [187]. The value of (< >) is recommended to be 1.26 for practical calculations [2]. 

Hydrodynamically Developing Flow. Bhatti [181] has analyzed hydrodynamically developing flow in elliptic ducts. The apparent friction factors and incremental pressure drop numbers can be expressed as ... 

TABLE 5.55 Fully Developed Friction Factors, Incremental Pressure Drop Numbers, and Nusselt Numbers for Some Quadrilateral Ducts [278]... 

Simultaneously developing flow in annular sector ducts for air (Pr = 0.7) has been analyzed by Renzoni and Prakash [287]. In their analysis, the outer curved wall is treated as adiabatic, and the boundary condition is imposed on the inner curved wall as well as on the two straight walls of the sector. The fully developed friction factors, incremental pressure drop numbers, hydrodynamic entrance lengths, and thermal entrance lengths are presented in Table 5.62. The term L y used in Table 5.62 is defined as the dimensionless axial distance at which /app Re = 1.05/ Re. The fully developed Nusselt numbers are represented by Nu/< in order not to confuse the reader since the thermal boundary condition applied in Renzoni and Prakash [287] is different from those defined in the section. 

K(o°) Incremental pressure drop number for fully developed flow, see Eq. 17.86 for definition, dimensionless... 

The indirect effect of aerosols on climate is exemplified by the processes that link S02 emissions to cloud albedo. Sulfur dioxide is oxidized in gas and aqueous phases to aerosol sulfate. Although increased S02 emissions can be expected to lead to increased mass of sulfate aerosol, the relation between an increased mass of aerosol and the corresponding change of the number concentration of aerosol is not well established. Yet, it is the aerosol number concentration that is most closely related to the cloud drop number concentration. Aerosol mass is created by gas-to-particle conversion, which can occur by growth of... 

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