Comparison of Measurement Techniques

Each of the frequency-response analysis methods described in the previous section has its place in the experimental arsenal. Their relative merits are siunmarized in the following sections. 

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Cui H, Mostoufl N, Chaouki J. Comparison of measurement techniques of local particle concentration for gas-solid fluidization. In Kwauk M, Li J, Yang WC, eds. Fluidization X. New York Engineering Foundation, 2001, pp 779-786. 

Andersson, S., Serimaa, R., Torkkeli, M., Paakkari, T, Saranpaa, R, and Pesonen, E. (2000). Microfibril angle of Norway spruce (Picea abies, L. Karst.) compression wood comparison of measuring techniques,/. WoodScL, 46,343-349. 

Cosgrove, D.J. (1987). Wall relaxation in growing stems comparison of four species and assessment of measurement techniques. Planta, 171, 266-78. 

Table 17. Comparison of different techniques for measuring molecular weight...

Figure 5. Comparison of measured values of Sorg between the ASTM and electron-optical techniques. Not all 56 points can be differentiated because some are coincident...

Fig. 4. Detection of single molecules by near-field techniques, (a), (b) SNOM images of single molecules embedded in a polymer film with random orientations, from [29]. (c) Sketch of the field distribution in the near field of the aperture, (d) Comparison of measured field distributions to calculated, once for both fundamental orientations, from [27]. (e) Effect of an optical antenna on the emission of a single emitter [36].

Each of the aforementioned techniques is capable of measuring powder that would be used in low-dose, solid oral dosage formulations. The technique must be compatible with the drug substance, and must be capable of producing the information that is needed. For example, if the particle size distribution is needed to ensure dose content uniformity, photon correlation spectroscopy can only provide an average particle size. In this instance, laser diffraction or image analysis would be more suitable techniques. Table 13.1 contains a comparison of the techniques that have been discussed. 

TABLE 1 Comparison of Measured Contact Angles H (deg) Using the Capillary Rise at a Vertical Plate Technique and ADSA-P for the Two Solid Surfaces. FC-72I and Teflon (FEP)... 

Comparison of several techniques (namely Fourier transform infrared spectroscopy (FTIR), simultaneous thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) and ultrasonic spectroscopy) for assessing the residual physical and mechanical characteristics of polymer matrix composites (PMCs) exposed to excessive thermal loads showed the measured power spectra of ultrasonic energy to correlate with performance of graphite fibre epoxy matrix composites exposed to thermal degradation, and also that analyses with the three techniques all pointed to the same critical temperature at which thermally induced damage increased sharply [58],... 

In the following, the measurement techniques and the fundamentals of the numerical modelling studies as well as their application on small scale domestic wood stoves will be described. Furthermore, relevant experimental results and information obtained by the numerical modelling studies as well as a detailed comparison of measured and computed data will be shown by means of an example for a commercially available tile stove heating insert. 

In the second phase of the development, the ability of property estimation of the network is examined with the data samples which are measured from the experimental process but never used in the training session. Based on the experimental data which were available for the trial, we trained and tested the ANN network to predict densities of FGM. Table 1 shows the comparison of measured and the network estimated densities of as-synthesized TiB2-Cu FGM using the Self-propagating High-temperature Synthesis (SHS) technique. The result indicates that the ANN network can give quite good estimations to the FGM properties. 

Rates of methane production via both acetate fermentation and C02 reduction were directly measured with radiotracer techniques in the sulfate-depleted sediments of Saanich and Princess Louisa Inlets (Kuivila etal., 1990). Comparison of measured and modeled rates suggests that these two pathways account for the majority of methane produced below the sulfate reduction zone in the sediments of both the basins. Prior aerobic degradation of the organic matter has little influence on the pathways of methane production. 

The technique which uses the ionic emission is called photon-stimulated desorption (PSD) The ion current due to PSD is proportional to the number of created core holes., i.e., to the photoabsorption cross section of the absorbate. It is a measurement of the surface absorption with a very high surface contrast in comparison with the previously discussed detection methods. A comparison of different techniques is given by Stohr et al. 

As mentioned above, only few comparisons of different techniques have been reported. For example, Jiang et al. (1992) studied the dilational elasticity of Triton X-100 adsorption layers with plane and cylindrical capillary wave. The results of the two measurements are given in Fig. 6.10. 

Before the introduction of measuring techniques such as pulsed field gradient (PEG) NMR ([14,16,45], pp. 168-206) and quasielastic neutron scattering (QENS) [49,50], which are able to trace the diffusion path of the individual molecules, molecular diffusion in adsorbate-adsorbent systems has mainly been studied by adsorption/desorption techniques [ 16]. In the case of singlefile systems, adsorption/desorption techniques cannot be expected to provide new features in comparison to the case of normal diffusion [51,52]. In adsorption/desorption measurements it is irrelevant whether or not two adjacent molecules have exchanged their positions. But it is this effect which makes the difference between normal and single-file diffusion. 

Wilhelm, K.P, Surber, C., and Maibach, H.l. (1989). Quantification of sodium lauryl sulfate irritant dermatitis in man comparison of four techniques skin color reflectance, transepidermal water loss, laser Doppler flow measurement and visual scores. Arch. Dermatol. Res., 281 293-295. 

If the measurements of the intensity of radiation from excited species are to be related to the concentration of ground state species, it is necessary to demonstrate that the species are in thermal equilibrium so that equation (3.33) may be apphed. This may be done by three methods. In the first place, the determination of flame temperature by the line reversal technique demands that there be thermal equilibration, and the concordance of a temperature so determined with that determined by other methods, or from lines known to be equilibrated is evidence for equilibration. Secondly the comparison of measured intensities of the first and higher resonance lines should be in accord with (3.33), a comparison which may be extended to a pair of different atoms if compound formation is not important. Thirdly, and most commonly, (3.33) may be transformed into... 

The optimum conditions for the analytical determination of TeO in presence of BrO, 10 and IO7 were found to be a drop time of 1 s, scan rate of 2 mV/s and a pulse amplitude of 100 mV. Response of the differential pulse peak height (ip, /lA) with the concentrations of TeO is linear at the optimum pH in presence and in absence of oxyhalide anions. The results of determination and resolution of TeO " in presence of oxyhalide anions are based on the calibration curves of TeO " alone by this technique. Table 1 shows the results of determination of TeO in presence are based on the comparison of measured ip... 

Mullin, J.W. and Ang, H-M. (1974) Crystal size measurement a comparison of the technique of sieving and Coulter counter. Powder Technology, 10, 153-156. 

Vial, C., Bendjaballah-Lalaoui, N., Poncin, S., Wild, G., and Midoux, N. (2003), Comparison, combination, and validation of measuring techniques for flow and turbulence analysis in bubble columns and airlift reactors, The Canadian Journal of Chemical Engineering, 81(3-4) 749-755. 

Three different techniques have been presented that all measure different flavors of photoinitiated CT distances. Indeed, a comparison of the techniques in Table 1 indicates many differences between them. Notably, the difference between vector and scalar dipole moment differences must be considered with respect to the geometry of the analyte, since scalar measurements do not necessarily yield the actual CT distances. Also, the analyte spectrum components must be clearly resolved. For example. Stark absorption on (bpy)Re(CO)3Cl would be very difficult due to overlapping ligand TTjTT and MLCT bands. Alternatively, its emission spectrum exhibits only the MLCT band, allowing Stark emission to easily measure the CT distance. The need for Stark spectroscopy samples... 

Table 9.3 Comparison of microstructural techniques used to measure grain boundary chemistry... 

Wilhelm KP (1995) Irritant dermatitis Experimental aspects. In Eisner P, Maibach HI (eds) Irritant dermatitis. New clinical and experimental aspects. Karger, Basel, pp 144-151 Wilhelm KP, Surber C, Maibach HI (1989) Quantification of sodium lauryl sulphate irritant dermatitis in man comparison of four techniques skin color, reflectance, transepidermal water loss, laser Doppler flow measurement and visual scores. Arch Dermatol Res 281 293-295 Wilkinson JD, Willis CM (1998) Contact dermatitis irritant. In Champion RH, Burton JL, Burns DA, Breathnach SM (eds) Textbook of dermatology, 6th edn. Blackwell, London, PP 709-731... 

Fig.7.41a-c. Comparison of different techniques for measuring the neon transition ls2 — 2p2 at X = 588.2 nm (a) intracavity saturation spectroscopy (Lamb peak of the laser output Il cd) with Doppler-broadened background) (b) laser-induced dichroism and (c) laser-induced birefringence [7.72]... 

Traditional inspection methods have known limitations (such as lack of accessibility to difficult- to-reach areas), can involve personnel safety concerns, and are not always reliable (such as operational inaccuracies due to scale formation, noise, or vibration) all of these add a measure of uncertainty to the effectiveness of the inspection and raise concern about the possibility of undetected corrosion problems in areas that cannot be inspected. For a comparison of monitoring techniques, see Table 3.1. 

Comparison of Experimental Techniques for Measuring Isosteric Heats of Adsorption,... 

A method was proposed for the parameterization of impedance based models in the time domain, by deriving the corresponding time domain model equation with inverse Laplace transform of the frequency domain model equation assuming a current step excitation. This excitation signal has been chosen, since it can be easily applied to a Li-ion cell in an experiment, allows the analytical calculation of the time domain model equation and is included in the definition of the inner resistance. The voltage step responses of model elements were presented for lumped elements and derived for distributed model elements that have underlying fractional differential equations using fractional calculus. The determination of the inner resistance from an impedance spectrum was proposed as a possible application for this method. Tests on measurement data showed that this method works well for temperatures around room temperature and current excitation amplitudes up to 10 C. This technique can be used for comparisons of measured impedance spectra with conventionally determined inner resistances. 

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