Packings factors affecting

The size of the group attached to the main chain carbon atom can influence the glass transition point. For example, in polytetrafluoroethylene, which differs from polyethylene in having fluorine instead of hydrogen atoms attached to the backbone, the size of the fluorine atoms requires the molecule to take up a twisted zigzag configuration with the fluorine atoms packed tightly around the chain. In this case steric factors affect the inherent flexibility of the chain. 

Factors Affecting tbe Efficiency of Packed Colunns in Liquid Chronatography... 

Mixing status in the tank has large affection on outlet response for the ice storage tank with out agitation. If the ice packing factor is small, thermal characteristics of the tank resembles to a stratified water tank. Since the ratio of sensible heat to latent heat is relatively large, conditions should be set to maintain stratification as much as possible. Therefore, large temperature difference in the inlet is preferable. 

Another factor affecting the lifetime of a membrane fluorophore probe is its proximity to the surface. The lifetimes of the DPH, DPH-phosphatidyl-choline (DPH-PC), and trimethylammonium-DPH (TMA-DPH) probes decrease in the order DPH > DPH-PC > TMA-DPH, as the probe locates nearer to the surface of the lipid bilayer.(7) The same is found for the anthroyl-stearate probes.(8) More recently, it has been shown that with TMA-DPH, the lifetime appears to be fairly sensitive to the differences in lipid bilayer packing induced by differing degrees of unsaturation in the phospholipid fatty acyl chains.(9) This aspect of the use of TMA-DPH and possibly other probes remains to be further exploited. 

CEC is a miniaturized separation technique that combines capabilities of both interactive chromatography and CE. In Chapter 17, the theory of CEC and the factors affecting separation, such as the stationary phase and mobile phase, are discussed. The chapter focuses on the preparation of various types of columns used in CEC and describes the progress made in the development of open-tubular, particle-packed, and monolithic columns. The detection techniques in CEC, such as traditional UV detection and improvements made by coupling with more sensitive detectors like mass spectrometry (MS), are also described. Furthermore, some of the applications of CEC in the analysis of pharmaceuticals and biotechnology products are provided. 

Factors Affecting HETP An Overview Generally, packing efficiency increases (HETP decreases) when the following occur. 

Since packing factors are derived from experimental pressure drop data, they are affected by the inherent limitations of the experimental data (Sec. 8.2.5). 

The factors affecting the development of wall flow are the same as those that affect the liquid spread. These include height into the bed, packing type, packing size, and liquid flow rate (66,140). 

The number of theoretical plates is a measurement of band spreading of a peak after it traveled through the chromatographic system. The smaller the band spreading is, the higher the number of theoretical plates. Four major factors affect the number of theoretical plates in a column the size of the particles, the distribution of particle sizes, whether the particles are fully porous or pellicular, and how well the column is packed. 

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