Bubble effect

Some plastics tend to react with zinc to give an undeskable bubbling effect when molded. There is also a tendency to darken due to tarnishing by the action of sulfides. Tarnish-resistant bronzes are available in which the particles have been coated with a transparent resin (9). 

The bubble model (Kunii and Levenspiel, Fluidization Engineering, Wiley, New York, 1969 Fig. 17-14) assumes constant-sized bubbles (effective bubble size d ) rising through the suspension phase. Gas is transferred from the bubble void to the mantle and wake at... 

Constant Reynolds number is not used for fermentation scale-up it is only one factor in the aeration task. This is also true for considering the impeller as a pump and attempting scale-up by constant momentum. As mechanical mixing tends to predominate over bubble effects in improving aeration, scale-up equations including bubble effec ts have had httle use. 

The inlet tube, preferably in the center neck, is placed in such a way that it nearly touches the bottom of the flask. Thereby nitrogen bubbles effect some agitation of the reaction mixture and prevent bumping of the boiling solution. 

FIG. 24. Optical micrographs of CdTe deposits formed using the thin layer flow cell, with 200 cycles (A) high-quality deposit (B) effect of bubbles in the cavity (C) edge effects and some bubble effects. 

A quantitative illustration of the relative magnitudes of shock and bubble effects is provided... 

In recent years it has become popular to characterize the effectiveness of industrial expls in terms of their measured underwater shock and gas bubble effects (Refs 6,18 21). For example, it is claimed (Refs 6 21) that measured gas bubble energies correlate well with performance of the expl in breaking rock... 

With the qualitative illustration of observable shock and bubble parameters shown in Fig 5, we can now proceed to a description of the test methods used to obtain such data. Figs 2 5 immediately suggest the use of pressure transducers to follow the pressure-time histories of underwater explns. Similarly Fig 1 (bottom portion) suggests the use of visual (photographic) techniques to obtain dimensions and positions of the gas bubbles. Indeed, these are the major techniques now used in studying underwater shock and bubble effects... 

The various factors (equal weight ratios) used to compare shock and bubble effects of different expls were described in Section I. In practice, any parameter of interest is obtained by multiplying the corresponding parameter of a standard expl (usually TNT) by the appropriate equal weight ratio. The following caveat should be noted ... 

Gas bubbles can also deactivate the electrode surface by forming a physical curtain [173,174], While bubble movement may enhance in situ mass transfer resulting in an increase of the current [175-178], the blocking effect of bubbles can distort measured parameters by introducing a sizable ohmic drop [179-183]. Bubble effects... 

Equivalent bed diameter on horizontal surfaces Equivalent bed diameter on vertical surfaces Gas diffusivity Diameter of nozzle Diameter of bed Diameter of bubble Effective bubble diameter Initial bubble diameter Maximum bubble diameter Maximum stable bubble diameter given by Davidson and Harrison (D3)... 

Gas Bubbles Effect on Detonation of Ex plosives. See F.P. Bowden et al, ProcRoySoc 188A, 291-311(1947) CA 41, 3627(1947) (The detonation of liq expls by gentle impact the effect of minute gas spaces)... 

Fluorine electrolysis is characterized by very large overpotentials and bubble effects [1, 2], The fluorine electrolyser has been extensively described in [3], The... 

It has been known for a long time that gas is formed during irradiation of PMMA. When the internal pressure of the gas formed in the reaction is sufficient to overcome the viscosity of the irradiated polymer, bubbling occurs. By suitable control of the irradiation dose and subsequent heating of the polymer, this bubbling effect can transform PMMA into a foamed material. Data on the volatile products formed at room temperature has been given by many workers [392—396]. The results are shown in Table 29. The yields seem to depend on the purity of the polymer sample. This problem will be discussed below in relation to the yield of chain scission. 

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