Profile analysis

Gribskov M, A D McLachlan and D Eisenberg 1987. Profile Analysis Detection of Distantly Re Proteins. Proceedings of the National Academy of Sciences USA 84 4335-4358. 

M Grihskov, AD McLachlan, D Eisenherg. Profile analysis Detection of distantly related proteins. Proc Natl Acad Sci USA 84 4355-4358, 1987. 

This relationship is true for each direction parallel to the surface independently. It is particularly useful for determining the size of adsorbate islands which lead to extra superstructure spots. A good introduction (in German) to spot profile analysis is given by Henzler and Gopel [2.249]. 

Fig. 4.29. EDXS line-profile analysis across the interfacial region of a C-fiber reinforced SiC composite and corresponding TEM bright-field image.

Besides the conventional Grimm-type dc source, which has dominated the GD-OES scene for approximately 30 years, other discharge sources are well known. Among those are various boosted sources which use either an additional electrode to achieve a secondary discharge, or a magnetic field or microwave power to enhance the efficiency of excitation, and thus analytical capability none of these sources has, however, yet been applied to surface or depth-profile analysis. 

The introduction of rfpowered sources has extended the capability of GD-OES to non-conductors, and several rf sources of different design have become commercially available. This is of the greatest importance for surface and depth-profile analysis, because there exists a multitude of technically and industrially important non-conductive coating materials (e. g. painted coatings and glasses) which are extremely difficult to analyze by any other technique. 

Because of the complex nature of the discharge conditions, GD-OES is a comparative analytical method and standard reference materials must be used to establish a unique relationship between the measured line intensities and the elemental concentration. In quantitative bulk analysis, which has been developed to very high standards, calibration is performed with a set of calibration samples of composition similar to the unknown samples. Normally, a major element is used as reference and the internal standard method is applied. This approach is not generally applicable in depth-profile analysis, because the different layers encountered in a depth profile of ten comprise widely different types of material which means that a common reference element is not available. 

In contrast with the dc source, more variables are needed to describe the rf source, and most of these cannot be measured as accurately as necessary for analytical application. It has, however, been demonstrated that the concept of matrix-independent emission yields can continue to be used for quantitative depth-profile analysis with rf GD-OES, if the measurements are performed at constant discharge current and voltage and proper correction for variation of these two conditions are included in the quantification algorithm [4.186]. 

Chw Discharge Optical Emission Spectroscopy (CD-OES) 229 Tab. 4.2. Some typical applications of GD-OES depth-profile analysis. 

H. Oechsner, Thin film and depth profile analysis, Springer-Verlag, Heidelberg 1984. 4-264 O. Dersch, M. Laube, E. Rauch,... 

When applied to the XRD patterns of Fig. 4.5, average diameters of 4.2 and 2.5 nm are found for the catalysts with 2.4 and 1.1 wt% Pd, respectively. X-ray line broadening provides a quick but not always reliable estimate of the particle size. Better procedures to determine particle sizes from X-ray diffraction are based on line-profile analysis with Fourier transform methods. 

The textural characterisation of the jellies was made by using the empirical technique of Texture-Profile Analysis (TPA) that allows the evaluation of the following parameters fracturability, hardness, cohesiveness, adhesiveness, springiness, gumminess and chewiness. 

Texture profile analysis is an empirical technique of double-penetration that simulates two bites of the jaw action. Data obtained from the Force-time plots enable the evaluation of seven texture parameters (Figure 1). 

The data from sensory evaluation and texture profile analysis of the jellies made with amidated pectin and sunflower pectin were subjected to Principal component analysis (PC) using the statistical software based on Jacobi method (Univac, 1973). The results of PC analysis are shown in figure 7. The plane of two principal components (F1,F2) explain 89,75 % of the variance contained in the original data. The attributes related with textural evaluation are highly correlated with the first principal component (Had.=0.95, Spr.=0.97, Che.=0.98, Gum.=0.95, Coe=0.98, HS=0.82 and SP=-0.93). As it could be expected, spreadability increases along the negative side of the axis unlike other textural parameters. 

US EPA (1974) Resource and Environmental Profile Analysis of Nine Beverage Container Alternatives. US EPA (US Environmental Protection Agency) Report No. EPA/530/SW-91c. 

The peak profile analysis techniques allow separating the intrinsic and extrinsic causes producing peak broadening and shift. Accurate peak profile analysis requires the instrumental broadening well characterized and, in general, significantly smaller than the one due to sample defects (size and strain). New high quality X-ray sources and... 

In this short summary of peak profile analysis, we only considered the broadening due to the dimension and the strain, and we have considered only the Fourier-cosines transform (i.e. the symmetric part of the peak) that is the most frequent case. 

In process profile analysis, points are awarded to processes in the following categories ... 

An example of the application of process profile analysis was provided by Berkoff and coworkers (Berkoff et al., 1986). It concerned the synthesis of 7,8-dichloro-l,2,3,4-tetrahydrowoquinoline (1) according to the two step sequence shown in Fig. 2.6. 

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