Visual analytical methods

Content analysis according to IDFB Regulations, Part 3 (Section 2.6.3) and EN 12131 (1998) (Section 2.6.2) is as follows  

Using tweezers, the individual pieces of plumage are separated into (A) whole 

A representative minimum sample of 0.2 g from the down/fiber container (E) is then subdivided in a second separation into down clusters (F), down fiber (G), waterfowl feather fiber (H), land fowl feathers and land fowl feather fiber (I) and residue (K). These components are also weighed and expressed as a percentage of the total weight of aU components. 

The components, according to IDFB Testing Regulations Part 3 are reported as follows  

To represent the visual analysis of the contents of the different components, several quality and labehng standards have been established. Based on EN 12934, down and feather filling materials are qualified in classes (Table 2.4). A problem for both consumer and manufacturer is that it is impossible to produce, for example, products with consistent 100% down content. There are often disparities between what is printed on the label (the manufacturer s claims for the product) and the actual composition of the down-feather filling after it has been laboratory tested. Standards have been developed detailing permissible deviations from the goal percentage. Table 2.5 represents permissible labeling-test disparities. Table 

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To date, the MALDI-TOF spectrometer provides the most specific separation spectrograms. Based on numerous test series with a known reference material, an extensive data base of spectrograms has been acquired. For goose, duck, eider duck, chicken, pheasant and turkey, the accuracy of bird species identification is almost 100%. Accuracy of the visual quantitative method is 5%. For most quality control purposes, this is sufficient (see also Section 2.4, Visual analytical methods). 

The use of an integral video screen in instruments presents very great advantages, both in the ease of operation and in the ability to develop and understand analytical methods. Complete analytical records can be stored in the instrument and a visual display of good calibration curves can be stored in memory and recalled at will. It is most useful to have a graphical display of atomisation peaks when using a furnace where a distinction can be made of the total absorbance peak and that due to the analyte absorbance. 

Since Steiner s aim was to improve immaterial qualities of foods, anthroposophic scientists have developed analytical methods, which aim to visualize this kind of inner quality. This is done by preparing watery solutions of the plant, meat or milk (= juices) which are then brought into reaction with metallic salts like copper chloride (copper chloride crystallization method)... 

The most broadly based application of the thermogravimetric analysis (TGA) has been visualized and exploited in the investigation of analytical methods, such as ... 

To characterize dendrimers, analytical methods used in synthetic organic chemistry as well as in macromolecular chemistry can be applied. Mass spectrometry and NMR spectroscopy are especially useful tools to estimate purity and structural perfection. To get an idea of the size of dendrimers, direct visualization methods such as atomic force microscopy (AFM) and transmission electron microscopy (TEM), or indirect methods such as size exclusion chromatography (SEC) or viscosimetry, are valuable. Computer aided simulation also became a very useful tool not only for the simulation of the geometry of a distinct molecule, but also for the estimation of the dynamics in a dendritic system, especially concerning mobility, shape-persistence, and end-group disposition. 

Factorial design, analytical methods, 624 Fast Blue B, Upid peroxidation visualization, 670... 

A colorimetric method based on the violet color produced by ferrous sulfate in sulfuric acid in the presence of N03 was announced by English in 1947 (Ref 9) and applied to the determination of NA and nltrosylsulfuric acid (NSA) in spent mixed acid. Since then a number of papers (Refs 13, 14, 15, 16 and 17) have extended the method to NOa, organic nitrates and RDX -HMX mixtures Analytical Methods The visual determination of the endpoint (appearance of a permanent brown color) in the dead-stop titrimetric method is reported accurate to 0.03ml (Ref 3) and was used recently by Frejacques and LeClercq (Ref 12) for analysis of Pentolites, Tetryls, NGu, NG prepns, and Nitroethane-EGDN expls. The endpoint has been criticized as difficult to see, and if problems arise, electrometric methods are available for detection (Refs 6,... 

Visual colorimetry, probably the oldest analytical method, was last used by the Greeks and Romans. This method found its scientific basis in 1729 when Pierre Bouguer theorised that if a given width of glass absorbs half of the light emitted by a source then double the width will reduce the fight by one quarter its initial value . 

The distribution of the polymer dispersion in building materials is sometimes better visualized by etching methods (see Sample preparation and analytical methods above), which partially dissolve... 

Control charts are used to compare the observed control values with the control limits and to provide a visual display that can be quickly inspected and reviewed. These charts have the concentration or observed value plotted on the y-axis versus time of observation on the x-axis. It is common practice to plot 1 month s data on a chart, usually only one or two points a day, but the time axis should be chosen to be appropriate for the method being monitored. An example of a control chart is shown in Figure 19-8, B, where the control values represent the three situations in Figure 19-8, A, with 10 values per situation for a total of 30 values. When the analytical method is operating properly, the control values fall predominantly within the control limits. When there is an accuracy problem, the control values are shifted to one side, and there may be several values in a row falling outside one of the limits. When there is a precision problem, the control values fluctuate much more widely, and there may be values exceeding both the upper and lower control limits. 

Throughout this chapter we have used graphical and analytical methods to analyze first-order systems. Every budding dynamicist should master a third tool numerical methods. In the old days, numerical methods were impractical because they required enormous amounts of tedious hand-calculation. But all that has changed, thanks to the computer. Computers enable us to approximate the solutions to analytically intractable problems, and also to visualize those solutions. In this section we take our first look at dynamics on the computer, in the context of numerical integration of X = f (x). 

The nicest possible summary of the transformation in instrumentation and objectivity can be read off a 1959 advertisement. In 1959 BA advertised their spectrometers by comparing analytical methods, wet chemistry, spectrographic methods, and direct reading (figure 6.1). An iconic summary was presented for each approach. As with any effective ad, the visual point is made quickly and clearly wet chemical analysis takes more steps than spectrographic analysis, which itself takes more steps than spectrometric analysis (using a direct reader). Furthermore, the steps involved are easier with spectrographic methods than with wet chemical analysis, and easier still with spectrometric methods. 

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