Shape concave

The specific concave shape of the isotherms of the properties of KC1 -K2TaF7 melts can be explained by the following ligand-replacement interaction ... 

In water, Scatchard plots showed clear concave-shaped curves whatever the pectin origin (figure 4A). Nevertheless, differences between sugar-beet and citrus pectins appeared in presence of ionic strength. While citrus pectins exhibited convex-shaped curves whatever the metal ion, sugar-beet pectins display convexe curvature for Cu2+ and Pb2+ but concave-shaped curves for the other three cations (figure 4B, in the case of Ni2+). 

An anticooperative mode of interactions was assumed in case of concave-shaped Scatchard plots, as alrea% proposed by other authors (Mattai Kwak, 1986 Gamier et al, 1994). A convexe curvature of the plots indicated a cooperative binding process (figure 4). 

The end of the capillary tube is heated until the glass is soft, then before it has time to cool it is touched on to the surface of a thin bubble of glass and a slight suction applied. This forms the window into a concave shape and draws it slightly down into the capillary, whose ends then protect it from damage. The bubble of thin glass should be thin enough to show interference colours. These windows will stand a vacuum provided atmospheric pressure is on the concave side of the window. If they are subjected to a pressure difference in the other direction, failure occurs due to the reversal of curvature. 

Formation of products and intermediate species, as well as disappearance of reactants during the photocatalytic reactions can be discerned by the evolution of positive (i.e., concave shape) bands and negative (i.e., convex shape) bands, respectively. 

In the continuous chain model, a large part of the deformation during extension of the fibre consists of the shear deformation as a result of which the chain orientation distribution contracts. This leads to the concave shape of the tensile curve, often found for polymer fibres. Therefore, this description of the extension of the fibre implies a strain hardening process. 

A t-bar that is curved in a concave shape, much like a shallow saucer. The stronger the curve, the more self-control is being implemented. An nmbrella shape signifies the person is obsessively controlling an action. 

On the other hand, in concave reagents, the reactive group is located within the cavity [7]. The concave geometry of enzymes is translated into artificial reagents. The concave shape is retained but the reactive group in the active site is replaced by a standard reagent of organic chemistry. Furthermore the concave... 

The meniscus of a liquid is the curved surface it forms in a narrow tube (Fig. 5.18). The meniscus of water in a glass capillary is curved upward at the edges (forming a concave shape) because the adhesive forces between water molecules and the oxygen atoms and —OH groups that are present on a typical glass surface are stronger than the cohesive... 

The discussion directly following Eq (6) provides a simple, physically reasonable explanation for the preceding observations of marked concentration dependence of Deff(C) at relatively low concentrations. Clearly, at some point, the assumption of concentration independence of Dp and in Eq (6) will fail however, for our work with "conditioned" polymers at CO2 pressures below 300 psi, such effects appear to be negligible. Due to the concave shape of the sorption isotherm, even at a CO2 pressure of 10 atm, there will still be less than one CO2 molecule per twenty PET repeat units at 35°C. Stern (26) has described a generalized form of the dual mode transport model that permits handling situations in which non-constancy of Dp and Dh manifest themselves. It is reasonable to assume that the next generation of gas separation membrane polymers will be even more resistant to plasticization than polysulfone, and cellulose acetate, so the assumption of constancy of these transport parameters will be even more firmly justified. 

Capillary condensation is also important in the binding of dust and powder particles by water. Particles separated by a thin layer of water are held together very strongly by capillary forces. The inhibition of evaporation due to the concave shape of the air-water interface enhances the duration of this particle binding. 

Scheme 6.12) [39]. Cyclobutane 33 was formed with perfect stereocontrol over the two stereogenic centers in a- and [3-position to the carbonyl group. The concave shape of the substrate forces a highly selective approach of the olefin. The relative and absolute configuration at the chlorine-bearing carbon atoms was not relevant, as chlorine was subsequently eliminated under reductive conditions. Compound 33 was further elaborated into (i)-sterpurene (34). 

The intermolecular [2 + 2]-photocycloaddition of para-tetrahydronaphthoqui-nones has been applied by Ward et al. to the synthesis of cyathin diterpenes [52], An example is represented by the total synthesis of ( )-allocyathin B3 (46), during the course of which the diastereoselective [2 + 2]-photocycloaddition of allene to substrate 44 served as one of the pivotal steps (Scheme 6.17) [53]. The addition delivered a mixture of regioisomers (r.r. = 80/20), from which compound 45 was separated. The facial diastereoselectivity was perfect due to the concave shape of the quinone. 

Donaldson and Snedickar (1971) studied jet impingement on flat plates as well as on convex- and concave-shaped objects. Base pressure changes were measured for all considered geometries and velocity measurements reported for the flat-plate geometry. The study indicated that wall jets are... 

A combination of Eqs. (13.167) and (13.168) yields the typical concave shape of the elastic stress-strain curve of well-oriented fibres. In Fig. 13.98 the calculated stress-strain curve is compared with the experimental curve at decreasing stress of a Twaron 1000 fibre. It shows almost elastic behaviour. By including the simple theory the tensile curve with yield can be calculated as shown in Fig. 13.99. 

As columns are overloaded for preparative work, peak shape often deviates from the Gaussian shape typical of analytical work. In preparative work, the peaks can assume a triangular shape because the adsorption isotherm is nonlinear. A typical isotherm is shown in Figure 6-37, where CM is the concentration of sample in the mobile phase and Cs is the concentration of sample in the stationary phase. At low concentration of sample (CM) there is a linear adsorption isotherm which results in Gaussian peak shapes. At a point when either the sample adsorption in the stationary phase or the sample solubility in the mobile phase becomes limited, the isotherm becomes nonlinear, assuming either a convex or a concave shape. Convex isotherms are the most common and result in peak tailing. Conversely, concave isotherms cause fronting of the peaks. 

However, for the field applied parallel to the a direction the nearly linear behavior expected for normal 3D superconductors is not found but, instead, a concave shape of the Bcz curve. This might be due to the low dimensionality of the salts and a corresponding small coherence length in a direction perpendicular to the field. With the anisotropic GL theory [104, 105, 106, 107] the critical field Bc2 in the direction can be written as... 

With a downward-opening concave shape as illustrated here, it starts by canceling only a part of the effect of ideal mixing then it more than cancels this effect and takes over in making the Gi iIRT curve switch from convex-upward to concave-downward. It is this switch in shape that indicates liquid/liquid behavior. The mixing term approaches its endpoints with an infinite slope so the GnJRT curve always starts out in the downward direction, no matter what model we use to estimate the nonideal behavior. 

According to Sontheimer s theory [41], two typical shapes of breakthrough curves may exist. In the case of the porous diffusion predomination (carbon F - 100) curve of breakthrough is vertical and exhibits convex shape to X - axis or when layer diffusion predominated (carbon N) concave shape of elongated S letter (it is marked by BIOT (Bi) - number). It was stated, that elongated shape of breakthrough curve is connected with dilution of adsorption face, what makes the achievement of equili-birium state difficult. Thus, adsorption described by curve of vertical shape is most convenient. 

Figure 9. Typical resistance dependence of temperature of an overdoped Tl-2201 thin film to show the concave shape of the normal state resistivity (circles) and that of an underdoped Tl-2201 thin film for comparison to show the convex shape of the normal state resistivity.

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