Property obscure

The absence of water may have other advantages for instance, lipases may act as esterification catalysts, a property obscured in water solution by the reverse, common hydrolytic reactions. 

How are we to choose between these positions Nerlich recommends position (3) on the basis of its clarity and explanatory power. Treating handedness and/or enantio-morphy as intrinsic is not the provision of an analysis, but the refusal to provide one. Positions (1) and (2) just leave these properties obscure. Position (3), in contrast, offers an explanation of why handedness must be extrinsic because in certain nonstandard spaces rigid motions of an asymmetrical object can be equivalent to reflection. We can readily visualize this in the case of two-dimensional enantiomorphs, as we already saw, and although the corresponding three-dimensional case is beyond our visual imagination, we can at least appeal to analogy. 

While bulk viscosity is a relatively obscure property of a liquid or a solid... 

Commercial PCNs were produced by several companies, eg, Koppers Chemical Co., Halochem, Prodelec, Bayer, and ICl, and marketed under a number of trade names including Halowaxes, Nibren waxes, Seekay waxes, and Clonacire waxes. However, the exact yearly or total production figures are obscure. In 1972, the estimated market for PCNs was less than 2300 t. This figure subsequentiy decreased as a result of the periodic reported toxicities that have accompanied the production and use of PCNs and the decreased overall utilisation of HAHs because of their unacceptable environmental properties. 

Resultant analysis, this procedure, developed by James Black and colleagues (Br. J. Pharmacol. 84,561-571, 1985), allows measurement of the receptor affinity of a competitive antagonist, which has secondary properties that obscure the receptor antagonism see Chapter 6.6 for further discussion. 

Table 21-IV shows some properties of the metals and their crystal forms. Since different crystal forms are involved in the series, trends in the properties are obscured. Figure 21-2 shows scale representations of the crystal structures of metallic beryllium, calcium, and barium.

Unfortunately, direct experimental proof of this mechanism is not available. Kinetic data (see below) offer none since the interpretation need not be unique—more than one mechanism can serve equally well. In addition, the physical properties of the catalyst are obviously contributing, and, in the extreme, diffusion can be rate-controlling, completely obscuring chemical mechanisms. 

Detector Sensitivity or the Minimum Detectable Concentration has been defined as the minimum concentration of an eluted solute that can be differentiated unambiguously from the noise. The ratio of the signal to the noise for a peak that is considered decisively identifiable has been arbitrarily chosen to be two. This ratio originated from electronic theory and has been transposed to LC. Nevertheless, the ratio is realistic and any peak having a signal to noise ratio of less than two is seriously obscured by the noise. Thus, the minimum detectable concentration is that concentration that provides a signal equivalent to twice the noise level. Unfortunately, the concentration that will provide a signal equivalent to twice the noise level will usually depend on the physical properties of the solute used for measurement. Consequently, the detector sensitivity, or minimum detectable concentration, must be quoted in conjunction with the solute that is used for measurement. 

The theory of electrolytic dissociation was not immediately recognized universally, despite the fact that it could qualitatively and quantitatively explain certain fundamental properties of electrolyte solutions. For many scientists the reasons for spontaneous dissociation of stable compounds were obscure. Thus, an energy of about 770kJ/mol is required to break up the bonds in the lattice of NaCl, and about 430kJ/mol is required to split H l bonds during the formation of hydrochloric acid solution. Yet the energy of thermal motions in these compounds is not above lOkJ/mol. It was the weak point of Arrhenius s theory that this mismatch could not be explained. 

The planar representation shown serves, in part, to obscure somewhat the complexity of the structural problem involved. Actually, four stereoisomers are represented by the simple planar representation shown it is not yet known with certainty which is the one corresponding to aldrin. Physically pure aldrin is a white crystalline solid with the properties set forth in Table I. 

On the other hand in the exciton description occasionnally adopted by some authors to interpret the main absorption peak in the polydiacetylenes one finds x " negative and its values two orders of magnitude lower than expression 6 since electron correlation (28) is essential in the exciton model, the calculation of even the simplest optical properties becomes prohibitively complicated and the physical insight is obscured. 

Fire hazard is a combination of several properties, including ignitability, flammability, flame spread, amount of heat released, rate of heat release, smoke obscuration and smoke toxicity. 

This secondary effect of materials is illustrated by the difficulties encountered, in a recent study [54], when attempts were made to correlate CO concentrations measured in small scale and full scale fire tests. The same small scale equipment (typically the cone calorimeter rate of heat release test) could predict adequately a number of very important full scale fire properties, including ignitability, rate of heat release, amount of heat release and smoke obscuration. It could not, however, be used to... 

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