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Phase before

Solvent Evaporation. This encapsulation technology involves removing a volatile solvent from either an oil-in-water, oil-in-oil, or water-in-oH-in-water emulsion (19,20). In most cases, the shell material is dissolved in a volatile solvent such as methylene chloride or ethyl acetate. The active agent to be encapsulated is either dissolved, dispersed, or emulsified into this solution. Water-soluble core materials like hormonal polypeptides are dissolved in water that contains a thickening agent before dispersion in the volatile solvent phase that contains the shell material. This dispersed aqueous phase is gelled thermally to entrap the polypeptide in the dispersed aqueous phase before solvent evaporation occurs (21). [Pg.321]

Final Vibration Amplitude and Phase Before Balancing In-Plane... [Pg.601]

The complexity of the system increases with the number of solvents used and, of course, their relative concentrations. The process can be simplified considerably by pre-conditioning the plate with solvent vapor from the mobile phase before the separation is started. Unfortunately, this only partly reduces the adsorption effect, as the equilibrium between the solvent vapor and the adsorbent surface will not be the... [Pg.13]

Dispersion caused by the resistance to mass transfer in the stationary phase is exactly analogous to that in the mobile phase. Solute molecules close to the surface will leave the stationary phase and enter the mobile phase before those that have diffused further into the stationary phase and have a longer distance to diffuse back to the surface. Thus, as those molecules that were close to the surface will be swept along in the moving phase, they will be dispersed from those molecules still diffusing to the surface. The dispersion resulting from the resistance to mass transfer in the stationary phase is depicted in Figure 8. [Pg.251]

Detection and result The chromatograms had to be freed from mobile phase before they were immersed otherwise a blue background was produced. After it had been dipped the chromatogram was dried in a stream of cold air. Zones appearing on an initially pale background were first brown and then turned blue. The background, however, darkened so much that after 5 min it was scarcely possible to discern the zones. Table 1 lists some hRf values. [Pg.175]

Detection and result The TLC plate was dried in the air for 30 min and heated to 110 °C for 10 min in order to remove the formic acid from the mobile phase, before immersing the chromatogram in the reagent solution for 10 s. [Pg.250]

Batch fermentation is the most widely used method of amino add production. Here the fermentation is a dosed culture system which contains an initial, limited amount of nutrient. After the seed inoculum has been introduced the cells start to grow at the expense of the nutrients that are available. A short adaptation time is usually necessary (lag phase) before cells enter the logarithmic growth phase (exponential phase). Nutrients soon become limited and they enter the stationary phase in which growth has (almost) ceased. In amino add fermentations, production of the amino add normally starts in the early logarithmic phase and continues through the stationary phase. [Pg.245]

The 2-ethoxyethanol was a by-product, as shown in Figure 5.13. The formation rate of 2-ethoxyethanol was the same as the conversion rate of the (S)- or (R)-ibuprofen ester one mole of 2-ethoxyethanol was formed when one mole of ester was catalysed. A known concentration of 2-ethoxyethanol was added in the organic phase before the start of the reaction for product inhibition. The plots of the kinetics for the free lipase system are presented in Figure 5.17 and immobilised enzyme (EMR) in Figure 5.18, respectively. The Kw value was 337.94 mmoFl 1 for the free lipase batch system and 354.20 mmoll 1 for immobilised... [Pg.133]

PoV)/(SqRT) = No/So No is the number of moles in the gas phase before the experiment), and thus with a decreasing pumping speed So. [Pg.358]

Both El and Cl require the analyte of interest to be in the vapour phase before ionization can take place and this precludes the study of a significant number of polar, involatile and thermally labile analytes. [Pg.54]

The presence of the matrix can cause chromatographic problems if added to the mobile phase before the column, especially if this is of small diameter. The low flow rates that are used require an increased concentration of matrix to be present in the mobile phase to ensure an appropriate amount reaches the probe tip. [Pg.147]

The INEPT experiment can be modified to allow the antiphase magnetization to be precessed for a further time period so that it comes into phase before data acquisition. The pulse sequence for the refocused INEPT experiment (Pegg et al., 1981b) is shown in Fig. 2.13. Another delay, A. is introduced and 180° pulses applied at the center of this delay simultaneously to both the H and the C nuclei. Decoupling during data acquisition allows the carbons to be recorded as singlets. The value of Z), is adjusted to enable the desired type of carbon atoms to be recorded. Thus, with D, set at V4J, the CH carbons are recorded at VsJ, the CH2 carbons are recorded and at VeJ, all protonated carbons are recorded. With D3 at %J, the CH and CH ( carbons appear out of phase from the CH2 carbons. [Pg.116]

The appearance of CO2 in the gas phase before precipitation of metal implies the production of a soluble Pd(0) complex such as [Pd(CO)2Bt2] . This receives support from the observation that three times as much CO is consumed as CO2 liberated before deposition of Pd. The following reactions may be involved... [Pg.335]

Apart from the choice of an appropriate stationary and mobile phase, the essential problem for PLC is to attain equilibrium in a three-phase system — between the stationary, mobile, and gas phases. In a nonequilibrated system, the velocity of the mobile phase in a thicker layer (i.e., the effect of solvent evaporation) is less in a lower part of an adsorbent. Such a situation leads to the diffusion of bands and deterioration of the adjacent bands separation. This can be minimized or avoided by prerunning the plate with the mobile phase before spotting of the sample and the saturated chromatographic chambers. [Pg.259]

The problems discussed above may be circumvented by eliminating the mobile phase before measuring the spectra of the eluites, as first demonstrated by Shafer et al. [379] for pSFC-FTIR. Each eluite was deposited on a moving glass plate, on which a layer of powdered KC1 or KBr had been laid down from methanol slurry for diffuse reflectance spectroscopy (SFC-DRIFTS). Solvent elimination SFC-FTIR after deposition of the eluites on to a moving ZnSe substrate is quite straightforward the window is moved to the... [Pg.477]

These results show that the 2,4-dichlorophenoxyacetic acid can remain stable, and exert its herbicidal effects, only during the initial lag phase before the rapid logarithmic phase of destruction takes place. This initial lag phase depends upon the previous treatment of the soil, particularly on whether it has already been exposed to 2,4-dichlorophenoxyacetic acid. Clearly, once a soil is enriched with 2,4-dichlorophenoxyacetic acid destroying organisms, the herbicide, if added to the soil, will have little or no value in the control of plants growing there. [Pg.247]

The duration of the M phase is largely determined by the time necessary for the formation of a functional metaphase spindle and the correct alignment of all chromosomes in the metaphase plate. The spindle assembly checkpoint prevents the exit from the M phase before the proper alignment of all chromosomes into a metaphase plate in many cell types. This kind of control is already operational... [Pg.84]


See other pages where Phase before is mentioned: [Pg.2543]    [Pg.218]    [Pg.221]    [Pg.342]    [Pg.233]    [Pg.218]    [Pg.1471]    [Pg.2230]    [Pg.304]    [Pg.157]    [Pg.5]    [Pg.136]    [Pg.270]    [Pg.207]    [Pg.303]    [Pg.329]    [Pg.331]    [Pg.218]    [Pg.222]    [Pg.413]    [Pg.507]    [Pg.234]    [Pg.29]    [Pg.542]    [Pg.237]    [Pg.798]    [Pg.33]    [Pg.449]    [Pg.770]    [Pg.35]    [Pg.366]   
See also in sourсe #XX -- [ Pg.307 ]




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