Zonal

O. M. Griffith, Techniques of Preparative, Zonal and Continuous Plow Eltracentrfugation, Spinco Division of Beckman Instmments, Inc., Palo Alto, Calif., 1975. 

Because at higher latitudes the coriolis force deflects wind to a greater extent than in the tropics, winds become much more zonal (flow parallel to lines of latitude). Also in contrast to the persistent circulation of the tropics, the mid-latitude circulations are quite transient. There are large temperature contrasts, and temperature may vary abruptly over relatively short distances (frontal zones). In these regions of large temperature contrast, potential energy is frequently released and converted into kinetic energy as wind. Near the surface there are many closed pressure sys-... 

Zonal models are often used in analytical calculation of temperature, concentration, or humidity conditions in ventilated spaces. The space is divided in two or several zones, which typically have different target levels as described in Section 2.1 These typical zones can also be divided into additional subzones. 

Zonal models can be applied for each room air conditioning strategy (see Section 8.6), but they are mostly used in stratification and zoning strategies with different air distribution methods (see Section 8.7). 

E. Shilkrot and A. Zhivov, Zonal model for displacement ventilation design, in Roonwcnt 96 vol. 2. Yokohama, Japan, 1996. 

The terms zonal model and flow element are also used for the simplified characterization of the flow field in a single enclosure. There, a zone represents a partial volume of air in the enclosure, whereas in the multizone models described here, a zone represents a specific enclosure which is connected to other enclosures by air conductances (see The Airflow Network later). 

Itiacd C., Ikmta H., Dalicieux P. Prediction of air temperature distribution in buildings with a zonal model. Energy and Buildings, vol. 24, 1996. 

Zone,/.zone region, district, zonenfbnnig, a. zonal. 

The possible advantages of this system over the equilibrium-limited reactor system are smaller catalyst beds, lower gas recycle requirements, and lower capital requirements. The possible disadvantages of this system are (a) practically no turn-down since any turn-down would be equivalent to decreased space velocities, closer approach to equilibrium, and higher temperature rises (b) maldistribution of gases across the bed would give rise to excessive temperature rises in zones of low flow and (c) considerably shortened catalyst life because of possible high local or zonal temperature and, concurrently, greater chances for carbon laydown. 

The control approach in both LO and SO can be either zonal or modal most theoretical and simulation work is being done using the modal approach which may have some advantages including the rejection of waffle modes and avoiding problems due to the central obscuration. 

Three regions of the atmosphere are seen to have significant zonal components of flow and thus of advection. The mid-latitude troposphere at the surface tends to exhibit westerly flow (i.e., flow from west to east) on the average. This region contains the familiar high- and low-pressure systems that cause periodicity in mid-latitude weather. Depending on the lifetime of the substances of concern, the motion in these weather systems may be important. 

There is a zonal atmospheric circulation system associated with this normal ocean condition called the Walker Cell (Eig. 10-7). Evaporation rates are high over the warm pool and warm moist air ascends to great heights (deep convection) producing extensive cloud systems and rain. The Walker Cell is closed by westerly winds aloft and subsidence in the high-pressure zone of the eastern Pacific. 

The histopathological examination of mice liver performed after a single dose of dibromobenzenes shows that 2 and 2 isomers resulted in zonal coagulative or haemorragic necrosis. It affected from 25-50 % to over 50 % of the liver parenchyma (i.e. 4-5 arbitrary units). 4 caused necrosis of only individual hepatocytes. 

In the absence of K the enzyme exhibits a basal Mg -ATPase activity that can be reduced, but not completely removed, upon further purification of the enzyme by free-flow or zonal electrophoresis [66,89]. Wallmark et al. [104] demonstrated that the rate of spontaneous breakdown of phosphoenzyme corresponded very well to the Mg -ATPase activity at low ATP concentrations, implying that this activity was not due to a contaminating Mg -ATPase with a reaction path independent of the phosphoenzyme. This conclusion was confirmed by Reenstra et al. [129] in a study on the nonhyperbolic ATP dependence of ATPase activity and phosphoenzyme... 

The association characteristics of purified E. coli were examined using zonal... 

This mode of chromatogram development is, in principle, almost identical with continuous development. The only feature that varies is the length of the developing path. In short bed-continuous development (SB/CD), this path is very short, typically equal to several centimeters [23-25]. This is the reason why this mode is preferentially applied for analytical separations. However, a similar technique is applied for zonal sample application and online extraction of solid samples, which are described in the following text. 

As noted already, Kuroko deposits are characterized by the following zonal arrangement in ascending stratigraphic order siliceous ore (quartz, chalcopyrite, pyrite), yellow ore (chalcopyrite, pyrite), black ore (sphalerite, galena, barite), barite ore (barite and quartz) and ferruginous chert ore (microcrystalline quartz, hematite). 

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