Capillary segment

Frictional length of the capillary segment packed with bare silica... 

Another application [12] uses a packed capillary segment combined with a bare silica section that serves to speed up the endo-osmotic flow, while the ODS-packed part of the capillary was used as the separation part of the capillary column. The detector s window was placed in-between the two segments. Monobasic sodium phosphate, 1.25 mM, pH 6.0, containing 75% v/v acetonitrile was used as background electrolyte at 625 V/cm, and 20 cm of the ODS-packed bed was used with the result... 

I. Foliar orians conspicuous and numerous at anlhob. divided into narrowly Unear to capillary segments, the ultimate segments ocarina apical and often latent aoUuiy or fasciculate tetulse. 

To prevent the buildup of ice that can cause poor modulation efficiency, a stream of nitrogen is sent between the cold trap and the capillary segment. By using CO2 as a cryogenic fluid, solutes as volatile as hexane cannot be successfully trapped and further modulated. 

LaManna JC, Cordisco BR, Kneuse DE, Hudetz AG. Increased capillary segment length in cerebral cortical microvessels of rats exposed to 3 weeks of hypobaric hypoxia. In Vaupel P, Zander R, Bruley DF, eds. Oxygen Transport To Tissue XV (Advances in... 

X2.2.2 This viscometer has measuring bulbs, B, C, and D, located on the viscometer arm, M, which is a precision bore glass capillary. The measuring bulbs are 20-mm long capillary segments, separated by timing marks, F, G, H, and I. 

In region III near the tube center, viscous stresses scale by the tube radius and for small capillary numbers do not significantly distort the bubble shape from a spherical segment. Thus, even though surfactant collects near the front stagnation point (and depletes near the rear stagnation point), the bubble ends are treated as spherical caps at the equilibrium tension, aQ. Region... 

II provides a transition between the two asymptotic limits. Viscous stresses now scale by the local thickness of the film, h, and the bubble shape varies from the constant thickness film to the spherical segment. Here the surfactant distribution along the interface may be important. Fortunately, for small capillary numbers, dh/dx < 1 and the lubrication approximation may be used throughout. Region II is quantified below. 

CE is based on the use of narrow-bore capillaries with internal diameters typically betwen 20 and 150 pm. Because most commercial instruments equipped with ultraviolet/visible (UV-Vis) absorption detectors use a segment of the same capillary as the detection cell, the path length in CE is much less compared to those in HPLC or spectrometry. Therefore, the most commonly used CE detectors... 

It is seen from equation (7) that the longitudinal diffusion term is a function of (k ) the capacity factor of the solute. While this may be a significant effect in LC capillary column systems, where the film of stationary phase is continuous along the length of the column, it will not be so in a packed column. The stationary phase in a packed column is not only broken into segments between each particle but also between each pore in each particle so free diffusion would be impossible. It follows that the longitudinal diffusion term for packed columns will be independent of the k of the solute or, very nearly so, and the experimental support for this will be discussed in the next chapter. 

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