Overlapping spots

In order not to confuse the two-dimensional pictures with too many overlapping spots, only very small samples of urine can be used on paper and then only the most abundant amino acids will show up. This disadvantage cannot be overcome. 

Figure 38 (A) First (solid line) and second (dash line) voltammetric cycles of a Ni(l 10)-c(2 X 2)S in LiC104/PE0 at 333 K (A). Scan rate 5 mV/s. The results in (B) were obtained under the same conditions on another slightly overlapping spot on the same specimen (see text for details).

When a paprika color standard, before saponification, was subjected to Cl8 TLC, a number of overlapping spots were observed, and a satisfactory separation could not be obtained. This was probably due to the paprika color containing a large number of esters. Paprika color is known to be hydrolyzed into a carotenoid and a fatty acid when saponified under mild conditions. Thus, a paprika color standard, after saponification, was subjected to TLC using a solvent system of acetonitrile-acetone-n-hexane (11 7 2) on a C18 plate. It was found that the paprika color standard, after saponification, was satisfactorily separated into a main spot having an Rf value of 0.50 and two subspots having Rf values of 0.60 and 0.75 (Fig. 3A). The main spot was identical with the spot of the capsanthin standard in terms of its Rf value, color, and shape (Fig. 3C). 

A multichannel detector for In-situ analysis of fluorescent materials on TLC plates was investigated (26). The optical system was designed to obtain a fluorescence spectrum from each position along the elution axis of a one-dimensional plate without the mechanical scanning. By use of tetraphenylporphlne and octaethylporphine it can be shown how overlapping spots can be resolved into their components. 

Color staining of the gel with GELCODE reveals protein patterns which are easily interpreted for qualitative analysis. The color aids in the analysis by distinguishing overlapping spots or bands which inherently have similar or identical isoelectric points or molecular weights. Quantitative analysis of color silver stained gel... 

Figure 7.1 (a) Pea lectin synchrotron Laue diffraction pattern recorded on photographic film on station 9.6 of the SRS and then in (b) the corresponding predicted Laue pattern is shown followed by those parts of the pattern which are (c) energy overlap spots, (d) spatial overlap spots, (e) spots which are both energy and spatial overlaps and, finally, those that are (f) neither energy nor spatial overlaps. From Helliwell (1985) with the permission of Elsevier. See Table 7.1, note 5 for experimental conditions (crystal to film 95 mm)... 

The triangulation approach is useful in the testing of threc-dimensioanl shapes to determine variations in depth by measuring scattered light from a surface illuminated by two overlapping spots [30]. Such systems have been developed to measure tire tread depth but suffer from poor resultion and dynamic range. For these reasons, laser based systems have been developed for improved precision and accuracy. 

The underline cursor is selectively erased and rewritten each time a character is entered. The laser, which has its heat sink maintained at 10 C by a thermoelectric cooler, emits about 15 mW GW. A pair of f/2 lenses collects and focuses about 3 mW into a 3x15 ym beam at the LC cell. Overlapping spots are written on 10 ym centers over a field of 7 mm diameter. The laser pulse time is 120 ysec which implies an energy of 0.36 yJ per spot. This is... 

Resistance Seam Welding (RSEW) uses two driven copper alloy wheels. Current is supplied in rapid pulses creating a series of overlapping spot welds which Is pressure tight. Usually floor standing equipment, either circular, longitudinal or universal types. 

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