System Comparison

Which operating system should be used for a particular separation problem Should the stem be operated in the gas or liquid phase Should adsorption, partition, size exclusion, or km exchange be used These questions ultimately revert to economics. At the current state of the art, exact answers are not available. However, some qu itative comparisons and general rules can be iltawn which should be helpful in selecting the process. The important question of whether a chromatographic or other type of separation should be used is not addressed. 

The choice of operating method also involves multiple rieciaons. The complexity of the eriuipmem increases in the following order. 

Special situations can modify these suggestions. For on-off chromatography, short fat colurmis are very useful, particularly if compressible gels must be used. Since these systems are similar to virater softening by ion exchange, the puls moving-bed methods used there may be applicable (as yet the scale has been fairly small). For viscous solutions the chromatofuge is a viable alternative. 

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Comparing two or more complex alternatives is more difficult than examining equipment capacity or first cost. Characteristics of alternatives should be weighted for relative importance and measured on a common scale to aEow proper evaluation. Many characteristics such as first cost, capacity, space requirement, and annual energy use can be measured objectively and used for system comparisons. Experience has shown that items such as maintenance expense, component life, and downtime can also be rehably estimated. Other factors, eg, system maintainabEity, flexibEity, and comfort, are more arbitrary. 

D. P. Landau, M. Krech. Spin dynamics simulations of ferro- and antiferromagnetic model systems comparison with theory and experiment. J Phys Condens Matter 77 R175-R213, 1999. 

Further details are given in the systems comparison under Comparative Evaluation of Traction Battery Separators , below. 

Other Monomer Systems - Comparison With Other Studies... 

P. de Willigen, Nitrogen turnover in the soil crop system—comparison of 14 simulation models. Feitil. Res. 27 141 (1991). 

Meredith M. (1991a). Sensory processing in the main and accessory olfactory systems comparisons and contrasts. J Ster Biochem Molec Biol 39(4b), 601-614. 

W. R. Green, J. B. Sullivan, R. M. Hehir, L. G. Scharpf, and A. W. Dickinson, A Systemic Comparison of Chemically Induced Eye Injury in the Albino Rabbit and Rhesus Monkey, Soap and Detergent Association, New York, 1978, pp. 405-415. 

Weibel, F.P. and Widmer, A. (2004). (System comparison. Integrated and organic apple production Part III Inner quality - substances of content and sensory tests) Systemvergleichsversuch Integrierte und biologische Apfelproduktion Teil III Innere Qualitat - Inhaltsstoffe und Sensorik , Schweiz. Zeitschrift fiir Obst- und Weinbau, 140(7), 10-13. 

For a number of the systems, comparisons were made between the effects of enantiomeric composition in the monolayer and corresponding melting-point-composition curves for the crystals. All of the latter gave clear evidence of racemic compound formation in the crystals, and this type of pattern was repeated in the monolayer properties. 

In this case the expectation of all calculated thresholds is calculated and can be used for system comparison. 

H. Wagner, K. H. Kostka, C. M. Lehr, and U. F. Schaefer. Drug distribution in human skin using two different in vitro test systems Comparison with in vivo data. Pharm. Res. 17 1475-1481 (2000). 

Figure 1-3 External Reforming and Internal Reforming MCFC System Comparison...

Abstract Quantitative receptor autoradiography methods have heen widely used over the last three decades to study the distribution and physiological role of a receptor in various tissues. This review provides an overview of in vivo and in vitro receptor autoradiography methods and their advantages as well as disadvantages in the study of receptors in the central nervous system. Comparison with immuno-histochemical and in situ hybridization methods is also highlighted in relation to the study of a given receptor in the nervous sytem. 

The selection of variables is of central importance for the outcome of a system comparison on environmental and resource use impacts. The ideal variable or set of variables respectively provides information and describes the state of environmental phenomena with certain significance. Thus, applying a set of variables should make it possible to monitor and assess the state of the environment, to identify changes and trends, to transmit scientific data to become relevant for policy, and to evaluate already implemented policy measures. The concept of environmental indicators is broadly accepted as an adequate tool. Accordingly, an indicator is defined as a parameter or a value derived from parameters, which indicates the state of the environment with significance extending beyond that which is directly associated with a parameter value. A parameter s definition in this context is a property that is measured or observed (OECD 1994). Fieri et al. (1996) states that the purposes of indicators are as follows ... 

Koloutsou-Vakakis, S., and M. J. Rood, The (NH4)2S04-Na2S04-H20 System Comparison of Deliquescence Humidities Measured in the Field and Estimated from Laboratory Measurements and Thermodynamic Modeling, Tel-lus, 46B, 1-15 (1994). 

Propylene Polymerization with the a-TiCl3-Al(C2H6)a-n-ffe )Catalytic System. Comparison between Two Samples of a-TiCla Sample A Ti/Cl = 2.96 (Initial Sizes of the Crystals <2 y. Sample B Ti/Cl = 3.00 (Initial Sizes of the Crystals within 1 to 200 fi—See fig. 7). 

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