Experimental design sensitivity

The experimental designs discussed in Chapters 24-26 for optimization can be used also for finding the product composition or processing condition that is optimal in terms of sensory properties. In particular, central composite designs and mixture designs are much used. The analysis of the sensory response is usually in the form of a fully quadratic function of the experimental factors. The sensory response itself may be the mean score of a panel of trained panellists. One may consider such a trained panel as a sensitive instrument to measure the perceived intensity useful in describing the sensory characteristics of a food product. 

The inherent sensitivity of NMR signals to the fluid-substrate interactions via a large number of mechanisms provides a direct connection between the NMR measurables, the pore structure and the motional characteristics of the imbibed fluid. While the large number of potential NMR variables makes the experimental design and analysis complex, it also provides the potential for a measurement method capable of measuring and spatially resolving the parameters of interest to functionalized ceramics. 

Acute inhalation lethality data for the rat, mouse, and rabbit for exposure times of 10 s to 12 h were located. A single inhalation study with the dog did not give an exposure duration. The data are summarized in Table 5-4. Data from studies with nonlethal concentrations are summarized in Table 5-5. Barcroft (1931) reported LC50 values and times to death for eight species of animals, the times to death at a constant concentration. Due to experimental design constraints, the LC50 values are not reported here, but relevant data are discussed in the section on relative species sensitivity (Section 4.4.1). 

As described in Section 7.4.2, one of the challenges of online LC-NMR is the need to match the chromatographic peak to the active volume of the CapNMR flow cell. An excellent discussion of the comparison of CapLC-NMR with other NMR probe types has been provided by Lewis et al. [17] Table 7.1 shows the sensitivity comparison of the CapNMR probe with larger volume probes. It is important to note that the experimental design used by these authors adjusted the concentration of analyte such... 

The in situ spectroscopies and the signal processing have limitations. Therefore, the set of observable species is a proper subset of all liquid phase species S. The validity of Eq. (4), namely, that the number of observable species is less than the number of species, is easily verified. Regardless of the instrument, the sensitivity is finite, and some dilute and most trace species must be lost in the experimental noise. In addition, numerous experimental design shortcomings further contribute to the validity of Eq. (4). 

In ICP-OES, it has been observed that analyte lines with high excitation potentials are much more susceptible to suffer matrix effects than those with low excitation potentials. The effect seems to be related to the ionisation of the matrix element in the plasma, but in fact it is a rather complicated and far from fully characterised effect [8,9]. Therefore, calibration strategies must be carefully designed to avoid problems of varying sensitivity resulting from matrix effects. A possible approach may be to combine experimental designs and multivariate calibration, in much the same way as in the case study presented in the multivariate calibration chapters. 

Dean, B.J. Johnstone, A. (1977) Dominant lethal assays in male mice evaluation of experimental design, statistical methods and the sensitivity of Charles River (CDI) mice. Mutat. Res.. 42. 269-278... 

Even if the linear equilibrium assumption is accepted, Rvalues measured in laboratory experiments will be sensitive to the solution chemistry and experimental design. If conservative predictions of the barrier time-to-breakthrough are desired, the supporting laboratory experiments should be carefully designed, as discussed in the following section. 

Naylor, C. and Howcroft, J. (1997) Sediment bioassays with Chironomus riparius understanding the influence of experimental design on test sensitivity, Chemosphere 35 (8), 1831-1845. 

Toxic effects of all classes of contaminants including metals, pesticides, and organic substances can be captured with the pT-method, as long as the test battery employed reflects a sufficiently wide spectrum of sensitivity. Furthermore, test organisms in a battery should be representative of aquatic biota. The composition of test batteries can be varied according to different aquatic environments and country-specific issues. Clearly, application of the pT-method is suitable for several experimental designs which are linked to toxicity testing (methods, test species, endpoints). 

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