Experimental concerns

The novelty of (9) is that the net homonuclear dipolar dephasing can be controlled by a systematic variation of the number of the Ho, Hi, and Hi blocks. This technique has the acronym of PITHIRDS-CT [55] and has the virtues that the effect of T2 is identical for all data points and that the rf field of all the pulses is only 1.67 times the spinning frequency. The only experimental concern is that very stable spinning or active rotor synchronization may be required for the implementation of PITHIRDS-CT. 

In its broadest terms the discussion of HPLC detection for chiral species must include the analysis of mixtures with achiral substances as well as the quality testing of, for example, the enantiomeric purity of a chemically pure drug form. The distinction between the definitions of chemical purity versus optical purity can not be overemphasized. In an efficient chiral HPLC system the latter problem is trivial, and if retention times are significantly different then any conventional detector such as RI, electrochemical, absorption, etc., could be used. Co-elutions are a major experimental concern in separations of mixtures and at this juncture it is not only prudent but absolutely necessary to involve a chiroptical detector to preferentially identify the chiral analyte. 

The selection of the set of samples that best covers the impurity and degradation profiles of the API is critical to successful method development. For a given API there are several ways to design the method development sample set some of which are more advantageous, but incur more risk in terms of the ability to track peaks from column to column and condition to condition. This section will address method development sample set design strategies, experimental concerns, and trade-offs. 

Most metals have several phases (those of palladium are given, amongst other results, in Table 7.3). This can be of serious experimental concern since many phases are only distinguishable by their modest spectral differences. 

Selection of the electric field to be used for experimental measurements also requires some care. In general, the voltage to be used should adhere to three experimental concerns ... 

In the first chapter, an overview of thermodynamic behaviors of non-equilibrium polymers is discussed. In the consecutive chapters, different properties of polymer blends are discussed, including surface tension, transition, crystallization, morphology, and flow behaviors. Miscibility and molecular characterizations of polymer blends are also covered in this book. Applications to various systems are reviewed, and both experimental concerns and references are supplied. 

The selection of the SEC column and the chromatographic conditions was based on several experimental concerns. The pore size of the SEC... 

Despite the popularity of in vitro experimentation concerning the cellular mechanisms of carcinogenic prevention by essential oil components (mainly by inducing apoptosis), there is no evidence that the direct administration of essential oils can cure cancer. There is evidence to suggest that the mevalonate pathway of cancer cells is sensitive to the inhibitory actions of dietary plant isoprenoids (e.g., Elson and Yu, 1994 Duncan et al., 2005). Animal testing has shown that some components can cause a signi cant reduction in the incidence of chemically induced cancers when administered before and during induction (e.g., Reddy et al., 1997 Uedo et al., 1999). 

Rohlfmg, D. C., Hicks, M. J., Janzen, J. Experimental concerns in determining temperature dependence of complex viscosities of polyolefin melts. Report from the Research Center of the Phillips Petroleum Co., Bartlesville, OK (1999)... 

The major information available experimentally concerning the orientational order of nematics is the second rank order parameter which is given by the Maier-Saupe theory as... 

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