Ethylene glycol transference data

Xi2 = ttansition dipole moment and = CT energy) Laidlaw et al. used a A i2 value calculated for transfer of 1 electron over the geometric Ru -Ru distance to afford j3o = 41 X 10" ° esu [26], whereas Vance et al. obtained jSq = 28 x 10 ° esu by using a A/Xi2 derived from Stark spectroscopy [in 1 1 (v v) ethylene glycol-water at 77 K] [27]. The discrepancy between the latter and that obtained from HRS (81 X 10 ° esu in water) may be due to errors arising from resonance-enhancement in the HRS data [27]. 

Marcos and Bergles [189] correlated their data for fully developed heat transfer for water and ethylene glycol in glass and metal tubes by the equation... 

Data for uniform-wall-temperature heating are plotted in Fig. 11.32, and the isothermal friction factors are plotted in Fig. 11.33. Twisted tapes and propellers were used by Koch [4] to heat air (curves a-d). Propellers produce higher heat transfer coefficients than twisted tapes however, this enhancement is at the expense of a rather large increase in friction factor, as seen in Fig. 11.33. Up to Re = 200, the friction factor for the twisted tape is the same as that for the empty half-tube (y = °o). The twisted-tape data of Marner and Bergles [114] with ethylene glycol exhibit an enhancement of about 300 percent above the smooth-tube values. Swirl at the pipe inlet does not produce any effective enhancement [192],... 

Tamari and Nishikawa [224] observed increases in average heat transfer coefficient of up to 400 percent when air was injected into either water or ethylene glycol. The injection point was at the base of the vertical heated surface, and up to three injection nozzles were used. Other studies are reviewed by Hart [225], who proposed a correlation to fit his own data as well as the results of other investigators for free convection enhancement. 

Tables 14.22.1 and 14.22.2 provide data on releases and transfers from both polymer manufaeturing and man-made fiber produetion in flie USA. Carbon disulfide, methanol, xylene, and ethylene glycol are used in the largest quantities. Carbon disulfide is used in manufacture of regenerated cellulose and rayon. Efliylene glycol is used in the manufacture of polyethylene terephthalate, the manufacture of aUcyd resins, and as cosolvent for cellulose ethers and esters. Methanol is used in several processes, the largest being in the production of polyester. This industry is the 10th largest contributor of VOC and 7th largest in releases and transfers.

Several years ago. Kohl anf Blohm presented gas-phase concen tration profiles measured in an industrial absorber where H2S and CO2 were absorbed simultaneously in a monoethanolamine/ethylene glycol/water solution. These data clearly show that in the lower part (rich end) of the absorber H2S is actually desorbed from the liquid phase (the concentration of H2S in the gas phase initially increases as the gas moves up the lower part of the absorber). Analysis of these data shows that in the bottom part of the absorber. Equations 79 and 80 hold true, but the equilibrium con ditions are such that the reverse mass transfer phenomenon may take place furthermore, in the bottom part of the absorber con ditions are indeed such that the reactions may be regarded as instantaneous. 

In conclusion, the ethylene glycol dibenzoate molecule is a good model for 26T since it not only reproduces the trans-trans-trans conformation of the methylenic part, but it also has an equiv-alent fiber repeat which exactly matches the observed fiber repeat of the 2GT polyester. This feature is arrived at with no distortion of the molecule. The geometrical and conformational data can be transferred as a whole to the polymer. 

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