Optical evaluation

U.E. Spichiger, D. Citterio and M. Bott, Analyte-selective membranes and optical evaluation techniques. Characterization of response behaviour by ATR measurements, SPIE, 2508 (1995) 179-189. 

In any optical evaluation of commercial sugars, the spectrophotomet-ric data in the visual spectrum are the primary ones, since all other results... 

One method of determining the mixing quality is to use optical evaluation. A suitable set-up is shown in Fig. 9.19. Here, the main stream being fed to the extruder is a clear oil. A side stream containing a tracer is introduced at some arbitrary position along the screw. This approach allows the length available for mixing to be varied. The extruder can be equipped... 

Figure 9.19 Experimental set-up for determining the mixing quality downstream of an extruder optical evaluation of gray-scale values to determine concentration...

Becker M, Scheel H, Christiansen C, Strunk HP (2007) Grain orientation, texture, and internal stress optically evaluated by micro-Raman spectroscopy. J Appl Phys 101 063531-1-06351-10... 

Wayner, P.C., Jr. Wang, Y.X. Zheng, L. Plawsky, J.L. Optical evaluation of the effect of curvature and apparent contact angle in droplet condensate removal. J. Heat Transfer 2002, 124 (4), 729-738. 

Detection Direct optical evaluation under 254-nm UV light using the TLC-Scanner II (CAMAG) The scans show the following pesticides from left to right ... 

Practical Tip for prewashing if the signal/noise ratio is too low (see Section 5.2 Direct Optical Evaluation Using Instruments ), the blank chromatography method should be given preference. 

Figure 55. Direct optical evaluation of spironolactone and furosemide from the contents of a capsule measured by the TLC Scanner II (CAMAG) at 254 nm...

Unhke visual evaluation of a chromatograms before derivatization, which can only give quahtative or semiquantitative results, direct optical evaluation using instruments enables quantitative results to be obtained. For this, a traditional TLC scanner, diode-array scanner or video equipment, either alone or in combination with a flat-bed scanner, is used. Quantitative evaluation with these instruments is described in more detail in Sections 1.2-1 A. However, the limits of this book would be exceeded if we gave a detailed description of all the commercially available equipment that can be used to quantify substances on TLC plates. Training in the use of TLC scanners can be obtained in company seminars (e.g. CAMAG) and detailed instructions are provided by the manufacturer when the equipment is purchased. 

Direct Optical Evaluation With 365-nm UV Light (Fluorescence Measurement)... 

This measurement has already been mentioned in Section 5.2.3 Direct Optical Evaluation below 400 nm , as the evaluation is performed without derivatization. However, the importance of this example hes in the quantitative results of the measmements of trimethoprim and sulfamethoxazole (both being pharmaceutically active), so that it seems more appropriate to discuss it here. 

Figure 96. Comparison of the direct optical evaluation of sulfamethoxazole and trimethoprim using parallel and transverse measurement at 285 nm using the TLC Scanner III (CAMAG)...

Figure 97. Direct optical evaluation with a video system. BASys software ID-page program (BIOTEC-FISCHER)...

Measuring equipment for the direct optical evaluation of thin-layer chromatograms... 

In many investigations the optical evaluation is sufficient to resolve the specific problem under investigation, thus eliminating more costly methods of analysis. 

The evaluation of new video endoscopic equipment is also difficult because of the lack of objective standards for performance. Purchasers of equipment are forced to make an essentially subjective decision about image quality. By employing virtual instrumentation, a collaborative team of biomedical engineers, software engineers, physicians, nurses, and technicians at Hartford Hospital (Hartford, CT) and Premise Development Corporation (Avon, CT) have developed an instrument, the EndoTester , with integrated software to quantify the optical properties of both rigid and flexible fiberoptic endoscopes. This easy-to-use optical evaluation system allows objective measurement of endoscopic performance prior to equipment purchase and in routine clinical use as part of a program of prospective maintenance. 

Ascertainment of smoke formation from a material is rather difficult due to the uncertainties in testing and evaluation. The measurement of smoke generation is to some extent dependent on the measurement technique i.e. whether smoke has been collected in a chamber or is streaming in a pipe whether gravimetric or optical evaluation is used and in the case of optical density, whether specific optical density, mass optical density, or a different measure is to be considered. 

Figure 7.6 Electrical and optical (evaluated by detecting the transmitted light at 490 nm) responses at the 1000th square wave (2 s period) and at the 1010th (8 s) of poly(dithieno 3,2-b 2, 3 -d thiophene), after [21].

Figure 7.9 Electric and optical (evaluated by detecting the transmitted light at 530nm) responses to linear potential sweep at 28mVs of the device ITO/PC-LiC104/pMeT/ITO (2.5 x mol MeTcm" ) AV is given with respect to pMeT/ ITO electrode, after [29].

J. Francois, A. De Rouck, E. Gambie, Retinal and optic evaluation in quinine poisoning. 

A different optical evaluation method based on the use of a cylindrical... 

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