Aerosol dispersion tube

Lipophilic 1,4-dihydropyridines, such as 4-aryl-1,4-dihydropyridines, exhibit significant calcium channel antagonist activity. N.R. Natale et al. have synthesized a series of 4-isoxazolyl-1,4-dihydropyridines bearing lipophilic side chains at the C5 position of the isoxazole ring." The Hantzsch synthesis was carried out in an aerosol dispersion tube at 110 °C in ethanol in the presence of 2 equivalents of ethyl acetoacetate and aqueous ammonia solution. 

There are a number of techniques for generating aerosols, and these are discussed in detail in the LBL report (1979) and in volumes edited by Willeke (1980) and Liu et al. (1984). We briefly review here the major methods currently in use these include atomizers and nebulizers, vibrating orifices, spinning disks, the electrical mobility analyzer discussed earlier, dry powder dispersion, tube furnaces, and condensation of vapors from the gas phase. 

Whipple, R. T., W. R. Chen, and C. S. Wang. The Dispersion of Aerosol Boluses in a System of Repeatedly Branching Tubes. Paper No. 19-D Presented at the 75th Meeting of the AIChE (American Institute of Chemical Engineers), Detroit, Mich., June 3-6, 1973. 21 pp. 

Volatile components of the aerosol produced by the nebulizer are evaporated in the drift tube to produce nonvolatile particles in a dispersed mixture of carrier gas and solvent vapors. Ideally, the temperature in the drift tube should be high enough to ensure the complete evaporation of solvents, yet not so high as to be able to volatilize the analytes. If solvent removal is incomplete, detector noise will increase. When extremely large... 

The primary purpose of the Sterilamp tube in air-conditioning systems has been to destroy microorganisms (22). Tests on the effect of 1 to 2 p.p.m. by voliune of ozone on E. coli sprayed into an air duct revealed that the organisms were not destroyed. This would confirm the data of Elford and Van den Ende ( ) that ozone is a poor disinfectant of air at low relative humidity. At high relative humidity these authors found that as low as 0.04 p.p.m. by volume destroyed bacteria dispersed in an aerosol. This would also agree with the results reported here, that organisms on surfaces and seeded on Petri plates can be destroyed by minute amounts of ozone. 

Because of the dissimilar elution curves shown in the previous figure, the nuclei which have lx about equal to fg or less also survive at the tube exit to a different degree. The transportation time of the nonadsorbable molecules is not much dispersed around fg, and the surviving fraction is expf—/ /f .). It can be shown that the nuclei carried by aerosol survive to a greater extent, given by ... 

Louey MD, Van Oort M, Hickey AJ. Standardized entrainment tubes for the evaluation of pharmaceutical dry powder dispersion. J Aerosol Sci 2006 37 1520-1531. 

Table 3.4 compares detection limits with secondary fluorescers to the results with the RMF method and 15-kV broadband excitation [16,17]. Four different fluorescence analyzers were tested (units A, B, C, and D), and the results were corrected for differences in performance for the energy-dispersive spectrometers employed on each unit. Unit A used a chromium anode tube, and unit B used a tungsten anode tube. Unit A was a commercial, general-purpose instrument. Unit B was specifically designed for atmospheric aerosol analysis, where closer coupling between the tube, fluorescer, sample, and detector could be employed with some sacrifice of insensitivity to specimen-positioning errors. Table 3.5 lists the x-ray tube operating conditions required for Table 3.4. For medium- to high-atomic-number elements, the secondary fluorescer method provides detection limits equivalent to the RMF element, but requires much higher x-ray tube power. For light elements.

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