Functional zone

In many mountain-industrial areas there are 3 1 landscape-functional zones with different extents of the anthropogenic transformation of natural environments. As a rule, the first zone is the spatial complex joining mines, pits and tails site area with almost whole degradation of soil and vegetation cover and high metal concentrations in dust, technogenic depositions, waters and plants. 

The simulated moving bed operational mode involves four distinct functional zones, the adsorption, purification, desorption and buffer zones. These zones are described in detail in other parts of this book. We now examine the function of each zone as it applies to p-xylene adsorption and which can be extrapolated to the other aromatics separations. 

The Parex and MX Sorbex processes are quite similar with regard to the adsorbent section mechanics so all of the discussion about the functional zones in the section for the Parex process applies to the MX Sorbex process also. The MX Sorbex process produces m-xylene at 99.5-99.8% purity at a recovery in excess of 95%. The major differences between the two technologies are the choice of adsorbent and desorbent... 

A similar pattern was obtained from the PAH concentrations at four functional zones in Liuzhou (He et al., 2005). The highest total PAH concentrations were observed at the sampling site south of an industrial zone during winter and spring, when the north wind dominates in Liuzhou. The main source of PAHs in Liuzhou was industrial fuel combustion, suggesting that the meteorological conditions affect the distribution and transportation of PAHs greatly. 

Studies conducted in Macao (Qi et al., 2000) showed that the PAH concentrations of commercial and traffic zones were higher than that of relatively cleaner function zones. 

Formation of different functional zones along the machine with optimized technical processes. 

Conventional machine systems try to meet these conflicting demands by the separate optimization of screw geometries in the individual functional zones. However, the shear rate is similar in every zone, because the screw speed is always the same, and the self-wiping... 

Figure 28.1. Comparison of structural liver lobule with functional acinar regions. The liver lobule is centered on the terminal hepatic venule (THV), also called the central vein, and assumes a roughly hexagonal shape with its vertices at the portal triads, which contain the portal vein (PV), hepatic artery (HA), and bile duct (BD). The liver acinus is centered upon the tract of blood vessels that branch from the hepatic artery and portal vein of the portal triads. Hepatocytes within the acinus are grouped within functional zones 1,2, and 3 located at increasing distances from the vascular tracts that interconnect adjacent portal triads.

Most dry reagent chemistries are designed to be self-contained analytical devices. Each element may have several functional zones that are introduced as single layers or combined into one layer during construction. Regardless of the number of layers present, all dry reagent elements have a support function, a reflectance function, and an analytical function (Fig. I). Some elements may also contain a sample-spreading function. 

Roots anchor plants in the ground as well as absorb water and nutrients from the soil and then conduct these substances upward to the stem. Approximately half of the products of photosynthesis are allocated to roots for many plants. To help understand uptake of substances into a plant, we will examine the cell types and the functional zones that occur along the length of a root. 

GeneralPlan A drawing that gives an overview on the functional zones of the entire facility. 

The contribution to the overall scenario is summarized through the three process steps shown in Fig. 3.18. Suppose that the developer has finished processing the initial version of the extruder functional zones in the flowsheet editor. This information is sent, under the control of the process engine, to MOREX (step 1). MOREX receives the extruder configuration, along with material and process parameters via XML. The engineer, then, starts the... 

Fig. 3.19. Experience-based reuse of functional zones in MOREX...

As the numerical simulation of flows inside a compound extruder is a complex task, engineers usually do not simulate complete units but concentrate on functional zones. Due to the modularity of a compound extruder, a wide variety of configurations is possible for any functional zone. ID simulations calculate averaged functions or determine an overview of a specific configuration on an empirical level. They are used to select a specific extruder setup to be simulated with finite element (FEM) or boundary element (BEM) methods. 

Even though in principal, the visualization of ID simulations in a three-dimensional space is not too meaningful, the visualization of a number of ID-functions with exact geometrical placement can be an interesting alternative. In addition to that, the simple and natural interaction metaphors that are used in VEs can ease the task of configuration construction. Figure 3.53 depicts the prototype we developed for the interactive configuration of twin screw extruders that uses fast ID simulations to prepare functional zones for expensive FEM simulations. 

As a result of both, ID and 3D simulation, the screw-configuration of the extruder will be modified in an iterative design and analysis cycle for each functional zone. The results of the simulations have to be interpreted by the users who then have to asses product quality based on their experience [145]. 

The expert works with the MOREX tool to design and simulate the functional zones and their screw element realizations. 

The document content is fetched and analyzed, and the structural composition is then transformed into the conceptual representation of the PDW Extruder, Functional Zone, Screw Element and their specializations in Subsect. 4.1.5). 

In the scenario described here, the expert needs to find sensible realizations of the functional zones that form the compounding extruder. In MOREX, he or she selects the current functional zone (a Filler Adding , in the case described here), and asks for a set of alternative realizations. The current problem situation is analyzed by the environment, and a semantic query is composed that can be executed on the experience repository. This problem definition consists of elements of several of the four areas introduced in Subsect. 4.1.5. 

The product part of the situation is composed of the design elements displayed in MOREX, i.e. the extruder, the functional zones, and already finished screw element realizations. The materials being compounded, and attributes like temperature or pressure, also need to be taken into consideration. For some of the elements, their user interface state is also important, as the currently selected zone is to be used as the central aspect of the query. 

The most important process element is the user s intention in this situation, i.e. Realize the current functional zone . This is normally determined by a user interface element being activated, e.g. a menu item being clicked. The current activity type of Create extruder realizations - synthesizing a model, in contrast to analyzing a number of alternatives or deciding on one of them - is also part of the situation. 

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