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Column method coefficient

C for 1 h. A 100 pL portion of the solution was injected onto a column (15 cmx 3.2 mm) of LiChroscob RP-18 (7 pm) for HPLC at room temperature, using acetonitrile-0.033 M phosphate buffer of pH 8.2 (1 2) containing 0.05% of ethyle-nediamine as the mobile phase (eluted at 1 mL/min). Fluorimetric detection involved excitation at 338 nm and measurement at 540 nm (or with a 430 nm cutoff filter). For 50 300 ng of drug injected on to the column, the coefficient of variation was 7-8%. The method permits a simple determination of (z>)-penicilla-mine in serum at therapeutic levels. [Pg.146]

Barring, H., Bucheli, T.D., Broman, D., Gustafsson, O. (2002) Soot-water distribution coefficients for polychlorinated dibenzofurans and polybrominated diphenyl ethers determined with the soot cosolvency-column method. Chemosphere 49, 515-523. [Pg.1245]

Water solubility determined by the generator column method by van Haelst et al. [244]. n-Octanol/water partition coefficients determined by Van Haelst et al. using the slow stirring method [245]. [Pg.111]

Fig. 18. Self-diffusion coefficients of benzene in NaX at 458 K PFG NMR, O (97) and (92) (JENS, A (13) deduced from NMR lineshape analysis, (10). Comparison with nonequilibrium measurements T, sorption uptake with piezometric control (93) , zero-length column method (96) o, frequency-response and single-step frequency-response technique (98). The region of the results of gravimetric measurements with different specimens (92) is indicated by the hatched areas. Asterisked symbols represent data obtained by extrapolation from lower temperatures with an activation energy confirmed by NMR measurements. Fig. 18. Self-diffusion coefficients of benzene in NaX at 458 K PFG NMR, O (97) and (92) (JENS, A (13) deduced from NMR lineshape analysis, (10). Comparison with nonequilibrium measurements T, sorption uptake with piezometric control (93) , zero-length column method (96) o, frequency-response and single-step frequency-response technique (98). The region of the results of gravimetric measurements with different specimens (92) is indicated by the hatched areas. Asterisked symbols represent data obtained by extrapolation from lower temperatures with an activation energy confirmed by NMR measurements.
Adsorption of Strontium in Equilibrium-Type and Column Experiments. Laboratory batch equilibrium experiments were used as a rapid method for selecting ion exchangers for testing in columns. Distribution coefficients were obtained for strontium adsorption by equilibrating 1 g of resin or zeolite in 100 ml of basin water and agitating for 24 hr at ambient temperature. After centrifuging, the concenti ation of strontium-90 in the supernate was determined. Table VI shows the measured dis-... [Pg.142]

However, it is common to use one of the numerical methods which generates all m columns of coefficients and to use only the required n. If we are interested in the ground state of the 2n electron system, then, presumably, we require the n columns which are associated with the n lowest values of the eigenvalue... [Pg.77]

GRADIENT-COLUMN METHOD OF DETERMINING THE VOLUME EXPANSION COEFFICIENTS OF ORGANIC CRYSTALS. KORESHKOV B D KRISTALLOGRAFIYA... [Pg.224]

Example 8 Calculation of Rate-Based Distillation The separation of 655 lb mol/h of a bubble-point mixture of 16 mol % toluene, 9.5 mol % methanol, 53.3 mol % styrene, and 21.2 mol % ethylbenzene is to be earned out in a 9.84-ft diameter sieve-tray column having 40 sieve trays with 2-inch high weirs and on 24-inch tray spacing. The column is equipped with a total condenser and a partial reboiler. The feed wiU enter the column on the 21st tray from the top, where the column pressure will be 93 kPa, The bottom-tray pressure is 101 kPa and the top-tray pressure is 86 kPa. The distillate rate wiU be set at 167 lb mol/h in an attempt to obtain a sharp separation between toluene-methanol, which will tend to accumulate in the distillate, and styrene and ethylbenzene. A reflux ratio of 4.8 wiU be used. Plug flow of vapor and complete mixing of liquid wiU be assumed on each tray. K values will be computed from the UNIFAC activity-coefficient method and the Chan-Fair correlation will be used to estimate mass-transfer coefficients. Predict, with a rate-based model, the separation that will be achieved and back-calciilate from the computed tray compositions, the component vapor-phase Miirphree-tray efficiencies. [Pg.1292]

SCREEN allows for the selection of urban or rural dispersion coefficients. The urban dispersion option is selected by entering a U (lower or upper case) in column 1, while the rural dispersion option is selected by entering an R (upper or lower case) in column 1. Determination of the applicability of urban or rural dispersion is based upon land use or population density. In general, if 50 percent or more of an area 3 km around the source satisfies the urban criteria (Auer, 1978), the site is deemed in an urban setting. Of the two methods, the land use procedure is considered more definitive. [Pg.302]

Another method to determine infinite dilution activity coefficients (or the equivalent FFenry s law coefficients) is gas chromatography [FF, F2]. In this method, the chromatographic column is coated with the liquid solvent (e.g., the IL). The solute (the gas) is introduced with a carrier gas and the retention time of the solute is a measure of the strength of interaction (i.e., the infinite dilution activity coefficient, y7) of the solute in the liquid. For the steady-state method, given by [FF, F2] ... [Pg.85]

But then is the characteristic polynomial of A, and its coefficients are the elements of / and can be found by solving Eq. (2-11). This is essentially the method of Krylov, who chose, in particular, a vector et (usually ej) for vx. Several methods of reduction of the matrix A can be derived from applying particular methods of inverting or factoring V at the same time that the successive columns of V are being developed. Note first that if... [Pg.73]


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