Incompletely Characterized Systems

Single crystals of a number of other iodinated phthalocyanines, tetrabenzoporphyrins, and triazatetrabenzoporphyrins have also been prepared127,131,133, as have crystals of Co(pc)Br127,131. Typically, these compounds have the stoichiometry M(L)Ilo, and it is likely that the structures are the same as for Ni(pc)I and Ni(tbp)I. All these compounds conduct well, but with a variety of temperature responses. 

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The analysis shown in Figure 1 is however incomplete. The medium is a three-component system consisting of two polar components (monomer and THF) and one non-polar (toluene). Correlations in terms of two components only lead to incomplete characterization and, if extrapolated, invalid conclusions. In Figure 3 the meso (isotactic) dyad frequencies of polymers produced by t-butylmagnesium bromide at 225 are shown as a function of the mol fractions of the three components of the medium. It is apparent that monomer itself acts as a polar solvent component decreasing the isotactic content in comparison to toluene. It should be noted that the polymerizations carried out at =... 

A H CWOg, cr, 298.15 K) -201.46 kcal mol. This result is less certain because of the Incomplete characterization of the final products. Ackermann and Rauh (2 ) have investigated the tungsten-oxygen system by mass effusion, mass spectroscopy, and x-ray diffraction. In the temperature range from 1300 to 1600 K, they have derived indirectly two values of A H (W02 qq, cr) = -190.9 and -188.0 kcal mol" (corresponding to -196.1 and -193.3 kcal mol", respectively, at 298.15 K, using all JANAF functions). 

For an overall view of transition metal systems one has to confront a number of problems besides correlation, or sometimes as a part of it many electrons in open shells producing large number of close-lying electronic states, different spin multiplicities, magnetism, metal-metal bonds, core or " semicore electrons that occupy the same part of the space as the valence shell, fast electrons requiring relativistic corrections etc. In addition, many of transition metal systems of practical interest are highly complex and often incompletely characterized, so that careful modeling is to be added to the list of difficulties. 

It is apparent that information on the reaction between sulfur dioxide and sugars in well-characterized systems is incomplete. Even less understood is the interaction of sulfur dioxide with sugars and other food ingredients in the vastly more complex systems represented by fruit and vegetable products. The intricate nature of these commodities makes it understandable that most studies have, of necessity, been empirical. Another complication results from the apparent variety of reactions induced in foods by sulfur dioxide. For example, in dehydrated foods and... 

This paper treats an extensive study (1,2,17,18) of i obe diffusion in aqueous solutions of the high-molecular-weight polymer hydroxypropylcellulose (HPC), which is rodlike, semiflexible, and uncharged. Several factors motivated our choice of this system 1) Earlier studies (19.20,21) of i obe diffusion in HPC revealed the bimodality of probe spectra. However, the physical properties and detailed parameterization of the lineshapes for the two modes were non-trivial and incompletely characterized. An objective of our wturk was to provide a more thorough study of ohservahle lineshape parameters. 2) The viscosity q of aqueous HPC solutions shows, at elevated concentration, an apparent change in the functional form of its concentration dependence. An objective of this paper is to resolve between possible interpretations of this change. 

Barium octylsulphate (BaOS) is virtually insoluble in water and does not form any liquid crystalline phase with water between 298 and 323 K. Addition of decanol to the aqueous system leads to the formation of the lamellar liquid crystalline phase, yet incompletely characterized. However, it appears that the lamellar phase exists at low water contents and probably occupies a small area in the phase diagram. The phase diagrams of the barium surfactant systems are compared with those of the corresponding systems with and Ca + counterions and the results are discussed in the light of electrostatic theory. 

The oxidation of acetate, acetoacetate, and fatty acids by a nonmito-chondrial system from pig heart has been described. The heart system consists of three parts (1) a particulate nonmitochondrial fraction (2) a group of soluble enzymes and (3) a coenzyme concentrate, incompletely characterized, but which is known to contain di- and triphospho-pyridine nucleotides, coenzyme A, and ATP. The system reflects many of the properties of intact mitochondria and lends itself to a study of the reaction sequences in the activation and oxidation of fatty acids. 

During conventional polymerizations of both HEMA and DEGDMA, complications resulting from diffusion limitations to termination and propagation are observed. Features such as autoacceleration, autodeceleration and incomplete conversion of double bonds characterize the rate behavior of these polymerizations. As TED is added to the reacting system, the carbon-DTC radical termination reaction is introduced. Diffusion limitations to carbon-DTC radical combination are lower than those to carbon-carbon radical termination as the DTC radical is smaller and much more mobile than a typical polymeric carbon radical. As a result, the cross-... 

For several years application of MRE to biological tissues has been an active area of research. Strategies either turns towards excised tissues (ex vivo) or towards living animals or humans (in vivo). The former allows more detailed studies of strain-stress relationships and thus are important for the characterization of heterogeneous biological systems. From a biological point-of-view in vivo results might appear more relevant. However they are difficult to obtain and one must keep in mind biases that could arise from incomplete or noisy data. 

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