Hardness differences

Samples prepared with stirring and poured into test tubes at different times (stopping the stirring) showed the sequence illustrated schematically in Fig. 2. The two layers were distinguishable because of dullness and hardness differences. At a reaction temperature of 80°C, the volume of the upper layer (elastomer continuous) decreases slowly and finally disappears at about 90 min. Samples of both top and bottom layers were studied by transmission electron microscopy techniques, and micrographs for a 10/90 COPE/PSN are shown in Fig. 3. Up to 90 min, samples exhibit elastomer continuous top and plastic continuous bottoms. 

Figure 37 shows the structure of the water complex with the four-armed tetraaza[12]-crown-4 (10). The water molecule is located in the center of the cavity and serves as proton donor to two trans nitrogen atoms. The water molecule also accepts hydrogen bonds from OH side groups attached to the other trans nitrogen atoms. Thus a tetrahedral encapsulation of the water molecule occurs. A remarkable aspect is that the conformation of the twelve-membered ring hardly differs from that of the free ligand (10). 

The reason for the different behavior of the two crystalline forms of Na6P3Ojo does not lie in a difference in the constitution of the anions. As chromatography shows, both modifications give identical solutions. The anions are also practically identical in the crystal (see Fig. 4). Their relative situations in the lattice are also hardly different, but the coordination of the Na ion does vary. In modification II, which hydrates slowly, all Na+ ions are surrounded octahedrally by oxygen, but in the rapidly hydrated form, I, (see Fig. 5), on the other hand, part of the Na+ ions are only tetrahedrally coordinated. It is conceivable that the low coordination of Na+ ions and the desire to increase this is the cause of the great tendency to hydration of Na6P3Oio whether essential changes in the lattice as a... 

Entirely different behavior with the ring-disk method and other diagnostic criteria is shown for passive and bare iron. However, the Tafel slopes hardly differ—110... 

By this method one obtains a simple analytic expression for the shielding potential. With the above values of pi and p2 this expression is hardly different from Hartree s self-consistent field calculated via incomparably difficult numerical techniques, and is even perhaps a bit more exact, as it lies between the self-consistent field with and without exchange in the case of the sodium atom. ... 

In the extensive literature concerned with the problem of hardness, different definitions of the term are found. Many authors even omit the definition of hardness altogether on the ground that the concept is self-evident. Hardness is, however, as difficult to define as it is to measure, since on applying all known methods, the result is always a function of the method applied. 

Stem W., 1951, Directional hardness differences in silicon carbide crystals, Ind. Diam. Rev., 11, 237-239, 255. 

The cultural history of ceramics mainly deals with making pottery, the oldest craft on which continuous knowledge is available. Of course this knowledge has increased over the years, but in numerous places in the world pots are still being made in a way which hardly differs from the methods which were applied thousands of years ago. This is also true for the production of non-cultural ceramics, like for example bricks. 

Since the ES solvent coordinate is no longer an independent variable, the reaction path is defined by the remaining coordinates r and 6, and these paths to the TS - for which the bend goes first, followed by the stretch which completely dominates as the TS is crossed - are very similar for the water and DMF solvents. Not only is the NES reaction path for each solvent different than the ES path for that solvent, the NES paths differ for the two solvents while the ES paths hardly differ at all. This illustrates that reaction paths depend upon important dynamical solvent characteristics, totally absent in an ES description. 

Methods which would produce a surface morphology dependent on the local hardness might, however, be applicable. One such experimental technique uses ultrasonic cavitation to detect hardness differences (18). The sample and an ultrasonic transducer placed near the surface to be studied are immersed in a liquid. 

Also the final dielectric constants of both membranes are similar. This indicates that the final amount of charge carriers hardly differs and the contributions of the lipophilic anion to the membrane conductance is of the same order as of the chloride anion. Membranes with the hemispherand, either free or covalently attached, have about the same resistance. Because at the low frequency part of the impedance spectra a slight distortion was observed with the hemispherands, kinetic measurements were carried out with the valinomycin containing membrane. 

Dissolution testing was performed on the five aberrant tablet formulations (n = 6 per formulation) and the target tablet formulation (n = 6) using the small volume dissolution method previously described. As shown in Table 10.6 and Fig. 10.6, the dissolution profiles for the aberrant tablet formulations with additional lubricant, diluent substitution, additional binder, and high tablet hardness differ from the profile... 

Sometimes a combination of bullet core materials is used to produce a hardness difference between the base and the nose (dual core bullets), for example, jacketed bullets with a lead nose and a steel base, a steel nose and a lead base, or a soft lead nose and a hardened lead base. 

A calculation using the delocalised orbital model yields a rectangular structure as expected [78], both with the two-structure and with the one-structure calculation. The bond lengths are 1.552 A and 1.367 A for the two-structure calculation and hardly different for the one-structure calculation. The resonance energy is quite small (-0.98 kcal/mol). 

Bradykinin 87 and kallidin (Lys-bradykinin-decapeptide), which are split off from the kininogen in the plasma by trypsin and kallikrein respectively (Fig. 10), hardly differ in their pharmacological activity. The most important effect of the kinins is a dilation of the peripheral vessels, which leads to an improved blood flow, in the kidneys for example, and therefore increases diuresis. By acting on the formation of angiotensin II, kinins can contribute to the regulation of blood pressure. Moreover, kinins cause a contraction of the bronchial muscle. 

The constant KV) which is called the ionic product of water, may be computed from equations (V-44) and (V-46), if partial molal free energies (potentials) of formation of all the reaction components in the corresponding standard states are known. For such standard states we select both the state of a hypothetical ideal solution with molal concentration of hydrogen and hydroxyl ions equalling unity and the state of hypothetical, absolutely undissociatcd pure water. Since in actual diluted solutions the activity of undissociated water hardly differs from the activity in its standard state, aji2 in the equation (V-51) may be considered as equalling unity so that then Km = K . The following expression is valid for a temperature of 25° C ... 

The distribution map of Phaeocystis presented here can hardly be improved, not even by ocean colour remote sensing the frequent cloud cover over the North Atlantic hinders satellite-borne observations, but not the CPR survey. Also, the pigment signature of Phaeocystis is not very specific (Antajan et al. 2004) so the absorption spectrum and therewith the light reflectance hardly differs from that of other fucoxanthin- and fucoxanthin-derivative-containing phytoplankton... 

Important new insights into the various ways in which the elements could be interrelated were gained during the middle decades of the nineteenth century. The German chemist Leopold Gmelin (1788-1853) pointed out in 1843 that whereas in some triads the atomic weights hardly differed at all, for example, in chromium-manganese-iron, in other triads... 

For many applications, the toughness of sPS is insufficient, which has thus led to many attempts in the past to increase its toughness significantly compared with HIPS by blending with rubbers. In the stress field of softer or harder particles than the sPS matrix, typical deformation processes inherent to the matrix are initiated. For rubber modification it is important that the application or test temperature is above the glass transition temperature of the rubber, otherwise the stiffnesses of the two components hardly differ from each other and local stress fields around the rubber particles are not formed. The formation of numerous deformation zones round the rubber particles is generally the basis of impact modification [10]. 

H4 the differences are marginal), whereas o-yy = -0.29 ppm remains near zero. Tesche (1994) also employed the IGLO method to calculate ctCHj) and ct(H4) and the results hardly differed from those of FULL LORG (Tesche, 1994). 

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