Steep slopes

A line of constant Xp is compared with a line of constant Fp in Fig. 7.9. It can be seen that the line of constant Xp avoids the regions of steep slope. 

Figure 7.9 The Xp parameter avoids steep slopes on the Fp curves, whereas minimum Fp does not. (Reprinted from Ahmad, Linnhoff, and Smith, Cost Optimum Heat Exchanger Networks II. Targets and Design for Detailed Capital Cost Models, Computers Chem, Engg., 7 751, 1990 with permission from Elsevier Science, Ltd.)...

Figure 16.3 shows the situation below the pinch at the pinch. If a cold stream is matched with a hot stream with a smaller CP, as shown in Fig. 16.3a (i.e., a steeper slope), then the temperature differences become smaller (which is infeasible). If the same cold stream is matched with a hot stream with a larger CP (i.e., a less steep slope), as shown in Fig. 16.36, then temperature differences become larger (which is feasible). Thus, starting with ATmin at the pinch, for temperature differences to increase moving away from the pinch,... 

Figure 36 is representative of creep and recovery curves for viscoelastic fluids. Such a curve is obtained when a stress is placed on the specimen and the deformation is monitored as a function of time. During the experiment the stress is removed, and the specimen, if it can, is free to recover. The slope of the linear portion of the creep curve gives the shear rate, and the viscosity is the appHed stress divided by the slope. A steep slope indicates a low viscosity, and a gradual slope a high viscosity. The recovery part of Figure 36 shows that the specimen was viscoelastic because relaxation took place and some of the strain was recovered. A purely viscous material would not have shown any recovery, as shown in Figure 16b. 

It appears that pesticides with solubiHties greater than 10 mg/L are mainly transported in the aqueous phase (48) as a result of the interaction of solution/sediment ratio in the mnoff and the pesticide sorption coefficient. For instance, on a silt loam soil with a steep slope (>12%), >80% of atra2ine transport occurs in the aqueous phase (49). In contrast, it has been found that total metolachlor losses in mnoff from plots with medium ground slopes (2—9%) were <1% of appHed chemical (50). Of the metolachlor in the mnoff, sediment carried 20 to 46% of the total transported pesticide over the monitoring period. 

A series of fixed trapezoidal cells that form a rotating table and each connected to a stationary valve in the center of the filter. The cell is designed with steep sloped bottom for fast evacuation of the filtrate. 

Steilheit,/. steepness, slope Photog.) contrast. Steilschrauber, m. helicopter. 

In their measurements with the cell (195) containing methanol, Non-hebel and Hartley1 verified by direct experiment that the addition of a small drop of water to either side of the cell, sufficient to give a mole fraction of I120 equal to about 0.001, produced a change in the e.m.f. equal to a few millivolts. This was attributed mainly to the proton transfer (44). The curve for HOI in methanol-water mixtures must thus have a very steep slope, as has been sketched on the right-hand side of Fig. 01. 

V-Surficial, weakly coherent, alluvial deposits readily eroded by water. (Vj-<3 percent slope V2-<12 percent slope). I-Incompetent, or weakly coherent, bedrock such as shales and tuffs readily eroded by water and (or) prone to mass movement on steep slopes (li-<12 percent slope l2->12 percent slope). C-Competent, or strongly coherent, bedrock such as layered lava flow rocks and igneous intrusives not readily eroded by water, nor generally prone to mass movement except for rockslides and rockfalls from very steep slopes and cliffs (Ci-<12 percent slope). 

Slight slopes that are convexo-concave Steep slopes that are straight and at a threshold angle... 

Given a sufficient period of time, in the absence of tectonic processes, continents would presumably be eroded flat to about sea level. It is not surprising, therefore, that most tectonically quiet areas on continents tend to have low elevations and are often flat, whereas tectonically active areas, mostly mountain belts, have high elevations and steep slopes (Figs 9-2 and 9-4). 

For sites on very arid land or on steep slopes, an armoring system, or hardened cap, may be more effective than a vegetative layer for securing a landfill. Operators should not depend on an agricultural layer for protection in areas where vegetation cannot survive. Many States allow asphalt caps as an alternative to vegetative covers. Some closures at industrial sites have involved constructing... 

Figure 15.9 The X P parameter avoids steep slopes on the Ft curves, whereas minimum FT does not. (From Ahmad S, Linnhoff B and Smith R, 1990, Computers and Chem Eng,7 751, reproduced by permission of Elsevier Ltd).

Contrary to popular concepts, sands do not always dominate arid and semi-arid zones. Aridisols occur on a wide variety of landforms, lithological formations and are of different ages. They are most common on stable land surfaces of Late Pleistocene or greater age in tectonically active deserts where they comprise alluvial fan, alluvial flats or stream terraces. Arid zones also include mountainous terrain with steep slopes (Nettleton and Peterson, 1983). Many arid or semi-arid zones include fluvial and aeolian materials of Pleistocene age. 

The calculations thus fail to indicate any substantial energy preference for the allowed paths with respect to the forbidden ones. An inspection of the overall shape of the surface confirms, however, that along the allowed CCW path a less steep slope has to be climbed (Fig. 18). The general conclusion is that steric and symmetry factors are so intimately interwoven that it is impossible to distinguish their relative importance in cases where the magnitudes of the two effects are similar. This can perhaps be taken as a warning that orbital symmetry rules should only be applied with some caution to very strained systems. 

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