Visual estimation

For dust-control work, it is recommended that a preliminary quah-tative examination of the dust first be made without a detailed particle count. A visual estimate of particle-size distribution will often provide sufficient guidance for a preliminaiy assessment of reqmrements for collection eqmpment. 

Colorimetric analysis based on visual estimation is not very exact. Some more accurate data on the H2, I2, HI system at equilibrium are shown in Table 9-1. The reaction is... 

A number of rotation photographs were made with molybdenum. K-radiation filtered through a zirconium oxide filter to isolate the Ka line. The positions of useful reflections, the indices of the planes producing them, and their visually estimated intensities are given in Table V. The factor placed beside the estimated intensity is a correction for the varying time of reflection, namely Vi — (wl/dsin 20)2, where l is the wave-length, and u and d represent respectively the index of the axis of rotation and the unit translation along it1). (A number of reflections... 

Observed and calculated intensities of reflections on two oscillation photographs, one of which is reproduced in Fig. 5, are given in Table III. The first number below each set of indices (hkl) is the visually estimated observed intensity, and the second the intensity calculated by the usual Bade-methode formula with the use of the Pauling-Sherman /0-values1), the Lorentz and polarization factors being included and the temperature factor omitted. No correction for position on the film has been made. It is seen that the agreement is satisfactory for most of the... 

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 s values and the visually estimated intensities for the four rings observed in the photographs are given in Table IV. The radial distribution function (Fig. 1) shows maxima at 1.27 and 2.29 A., the second being about twice as large as the first. 

Jones, H.G. (1979). Visual estimation of plant water status in cereals. Journal of Agricultural Science, Cambridge, 92, 83-9. 

Sobrado, M. A. (1987). Leaf rolling - a visual estimate of water deficit in corn (Zea mays L.). Maydica, 32, 9-18. 

Figure 6.2. Illustration of fitting Eq. (6-2, solid curve) to open-loop step test data representative of self-regulating and multi-capacity processes (dotted curve). The time constant estimation shown here is based on the initial slope and a visual estimation of dead time. The Ziegler-Nichols tuning relation (Table 6.1) also uses the slope through the inflection point of the data (not shown). Alternative estimation methods are provided on our Web Support.

Visual estimation of nanoscrolls yield is difficult because they concentrate near the edges of copper grid support used in TEM studies. Nevertheless TEM images provide clear evidence of nanoscrolls presence in large amount. 

The chitobiose unit has been treated as a rigid body, and by using the full-matrix, least-squares, rigid-body, refinement procedure, the structure was refined to an R factor of 40.7%. Visually estimated intensities were used. The structure was found to be free from short contacts, and to be stabilized by an intrachain OH-3—0-5 hydrogen-bond and one interchain N-H—O hydrogen-bond. 

Compare the results with a graphical (visual) estimate. 

An example of release testing by TLC is shown in Fig. 13.24. In this example, two more polar bands are observed, one that is quantitated at <0.1% and another at 0.3%. Quantitations are based on visual estimation using the standards on the plate. Alternatively, scanning densitometry can be utilized to obtain a more definitive quantitation of impurities. 

Price ML, Butler LG (1977) Rapid visual estimation and spectrophotometric determination of tannin content of sorghum grain. J Agric Food Chem 25 1268-1273... 

Plutonic rock classification by petrologic means is a simple procedure involving the use of Streckeisen ternary diagrams. Unfortunately, classification suffers from modal estimation errors involving visual estimates, or representativity issues from point counts or image analysis procedures applied to thin sections or slabs of insufficient size. 

Variability of visually estimated wetted 0 0.7 Medium success... 

Natural budworm densities were determined by sampling 6 sprays, each 40 cm long, In the same quarter of the tree used to collect tissue for chemical analysis and to collect defoliation data. Densities were expressed as the average number of budworm larvae per 100 buds per tree. A visual estimate of the amount of defoliation eilso was made In the same area of the crown where the densities and needle tissue were collected. Since budworm may disperse from heavily defoliated trees, (Greenback, 1963) budworm densities from each tree were weighted by the level of defoliation that each tree sustained. This resulted In an Infestation Intensity measurement (dependent variable) which was subjected to multiple stepwise correlation analysis using various foliage quality and physical tree parameters as the Independent variables. Thirty-one parameters were used as Independent variables In this analysis. 

The pure compound salvinorin A is active at 200 - 500 meg when vaporized and inhaled. Since very few people have the costly equipment necessary to accurately weigh anything close to this small an amount, it is inevitable that people will try to visually estimate the dose. Unfortunately there is little room for error before the effects become potentially dangerous. 

Although only visual estimates of intensities were used, the number of reflections for which calculations were made is so large that the parameters may be accepted with considerable confidence. A view of the structure seen along the h axis is shown in Fig. 183. 

Table 5.1. Intersection points from Fig. 5.4 for ij0 vs cM in polystyrenes of various concentrations (visually estimated)...

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