Visual method

A visual method is considered by the most of regulations in force as a base for rope inspection. Instrumental methods using rope flaw detectors are considered as additional ones. But the visual methods have the number of shortcomings ... 

Evaluation data taken from the more than 8 thousand reports of the laboratory and field wire ropes inspections show that the visual methods and life time criteria are non adequate to real durability of the ropes in service [4]. The data show that only a very small percentage of all ropes was replaced in a proper time, when one has used a visual inspection. 

When comparing the magnetic particle- and penetrant inspection with other visual methods it appears that our viewing eonditions are not so bad, compared with other methods. In radio-graphie the contrast on the film is mueh lower. In ultrasonies and eddy current the presentation times on the screen is shorter and the contrast is lower. 

Using this assumption, one ean apply this flow visualization method to any working medium. 

In order to control the movements of contaminants it is useful to be able to see how both the contaminant and the induced airflows move. A number of flow visualization methods have been developed some are more suitable for laboratory research applications whereas others are quite widely used in industrial situations. We are primarily interested in this latter category. The methods involve releasing a tracer (for example gas, aerosol, or heat) and making visible its path. While in most cases the methods are subjective, their use is invaluable. Ideally the tracer should be nontoxic, nonirritating, inexpensive, and highly visible at low concentrations. The system should be easily portable, self-contained, easy to use, and be controllable. 

To involve the staff in a change process, of which the installation or improvement of a ventilation system is one example, is also of vital importance for a successful result. Their knowledge of how the work is or may be done in an effective way, combined with the knowledge of the ventilation expert, increases the chance for an effective and durable solution of an air quality problem. Visualization methods have thereby proved to be effective both to communicate important knowledge and to motivate the staff to take part in the process. ... 

For determination of the end point by a visual method, add 1-2 mL of 1 per cent starch solution, and stop the titration immediately the solution has acquired a uniform blue colour. 

Visual methods have been virtually displaced for most determinations by methods depending upon the use of photoelectric cells (filter photometers or absorptiometers, and spectrophotometers), thus leading to reduction of the experimental errors of colorimetric determinations. The so-called photoelectric colorimeter is a comparatively inexpensive instrument, and should be available in every laboratory. The use of spectrophotometers has enabled determinations to be extended into the ultraviolet region of the spectrum, whilst the use of chart recorders means that the analyst is not limited to working at a single fixed wavelength. 

Because of the difficulty of obtaining satisfactory photometer records of electron diffraction photographs of gas molecules, we have adapted and extended the visual method to the calculation of radial distribution curves, by making use of the values of (4t sin d/2)/X obtained by the measurement of ring diameters (as in the usual visual method) in conjunction with visually estimated intensities of the rings, as described below. Various tests of the method indicate that the important interatomic distances can be determined in this way to within 1 or 2% (probable error). 

The radial distribution method, while thus not completely independent of the usual visual method, is sufficiently different from it to lead in some cases to somewhat different values for interatomic distances. We feel that these values carry some weight, and we have accordingly discussed by the new method a number of molecules whose structures as determined by the usual visual method have been reported in earlier publications, and have then combined the results of the two methods in presenting a revised set of values of interatomic distances for these molecules. 

It is seen that the calculation of a radial distribution curve is closely similar to the calculation of a simplified theoretical intensity curve for the usual visual method, the summation being over the rings seen on the photograph instead of over the interatomic distances in the assumed model but whereas in the usual treatment the calculation may need to be repeated for many models, a single curve only is required for the new method. 

Carbon Tetrachloride.—By the usual visual method and by other methods involving microphotometer records, we have assigned8 to the carbon tetrachloride molecule the value 1.760 0.005 A. for the C-Cl distance, a value supported by other recent work.9 The radial distribution function for this molecule calculated by Equation 6, using the ten terms for which data are given in Table I, is shown in Fig. 1. 

Bromine and Chlorine.—Accurate values of the internuclear distances in the molecules Bra and Cl2 are known from band spectral studies, namely, Br-Br = 2.281 A. and Cl-Cl = 1.988 A. The visual method led to results (2.289 A. and 2.009 A., respectively) in satisfactory agreement with these.8 Radial distribution curves for these substances are shown in Fig. 3, the data used being given in Tables II and III. For bromine, with seven rings, three different estimates of intensities lead to the same Br-Br distance, 2.270 A., less... 

Benzene.—A careful study of photographs of benzene both by the visual method and by the analysis of microphotometer records8 has led to the value C-C = 1.390 = = 0.005 A. for the edge of the plane hexagon formed by the carbon atoms, in agreement with the values 1.39 = = 0.03 A. and 1.40 = = 0.03 A. reported by Wierl.1 The accuracy of this determination and the fact that the various carbon-carbon distances are geometrically related... 

Radial distribution Visual method Final values... 

The radial distribution method of interpretation is applied to a number of molecules previously investigated, and revised values of interatomic distances and bond angles, obtained by considering the results of this method as well as of the usual visual method, are presented (Tables XI and XII). 

Analyses for the Saxitoxins. Early methods for analysis of the saxitoxins evolved from those used for toxin isolation and purification. The principal landmarks in the development of preparative separation techniques for the saxitoxins were 1) the employment of carboxylate cation exchange resins by Schantz et al. (82) 2) the use of the polyacrylamide gel Bio-Gel P2 by Buckley and by Shimizu (5,78) and 3) the development by Buckley of an effective TLC system, including a new solvent mixture and a new visualization technique (83). The solvent mixture, designated by Buckley as "E", remains the best for general resolution of the saxitoxins. The visualization method, oxidation of the saxitoxins on silica gel TLC plates to fluorescent degradation products with hydrogen peroxide and heat, is an adaptation of the Bates and Rapoport fluorescence assay for saxitoxin in solution. Curiously, while peroxide oxidation in solution provides little or no response for the N-l-hydroxy saxitoxins, peroxide spray on TLC plates is a sensitive test for all saxitoxin derivatives with the C-12 gemdiol intact. 

An advantage of non-hierarchical methods compared to hierarchical methods is that one is not bound by earlier decisions. A simple example of how disastrous this can be is given in Fig. 30.13 where an agglomerative hierarchical method would start by linking A and B. On the other hand, the agglomerative methods allow better visualization, although some visualization methods (e.g. Ref. [28]) have been proposed for non-hierarchical methods. 

The least expensive visualization method in the diagnosis of lung cancer. Readily accessible and does not require systemic administration of contrast dye. However, it often detects lesions that are not cancerous and is not capable of assessing lymph node status. 

Organotin stabilisers in PVC compositions were determined by means of TLC [518]. The determination of inorganic species (down to ppb range) by TLC has been reviewed on several occasions [519,520]. Instrumental methods successful in the quantitative estimation of inorganic TLC zones directly on the plate are densitometry, fluorimetry, radiometry, planimetry and visual methods. In the framework of recycling studies, in particular as to metal stabilisers in PVC, Braun and Richter... 

In a landscape image, the data are presented as a surface, where the height at each point is proportional to the fluorescence intensity compression algorithms are not used with this visualization method, although the image can also be processed to saturate the most intense components. 

A simple visual method to evaluate the rate of solvent/electrolyte migration through the porous electrode body has been developed. The method enables an express selection of carbon materials according to the mobility of electrolyte in their pore structure. 

This review will highlight the interrelationships between basic photopolymer science and practical applications of this technology. Each application of photopolymer technology can be described in terms of three primary descriptors the mode of exposure, the mechanism of the photopolymer reaction employed and the visualization method used. Using this foundation, the widely diverse applications of photopolymer technology to electronic materials, printing materials, optical and electro-optical materials, the fabrication of devices and polymeric materials, adhesives and coating materials will be discussed. 

In the previous section, five basic mechanisms of photopolymer reactions were identified. In order to utilize these photopolymer mechanisms in practical systems, sensitive visualization methods must be used to develop the latent images. Six different classes of visualization techniques are used in most commercial applications of photopolymer technology. 

---