L accuracy

Capacity, /XL Accuracy, % Precision, % Capacity, /a,L Accuracy, % Precision, %... 

For Rd > L one gets R ff RD, while if Rd < L, R L. Accuracy of this formula when Rd L is not clear. To check it up, calculations were done for two typical cases corresponding to shallow donors in semiconductors (ro = 20 A) and deep centres in ionic reaction (ro = 2 A) [65], In the first case the reaction is controlled by a drift in the Coulomb field, when L > Rd within all the intervals of the diffusion coefficients considered (Fig. 4.5(a)) whereas in the second case, quite on the contrary, the recombination is controlled by tunnelling (Fig. 4.5(b)). What is surprising, that in both cases equation (4.2.31) describes the explicit result very well even if Rd L It could be shown that has to exceed the L by the value L/2... 

The ability to perform the same analytical measurements to provide precise and accurate results is critical in analytical chemistry. The quality of the data can be determined by calculating the precision and accuracy of the data. Various bodies have attempted to define precision. One commonly cited definition is from the International Union of Pure and Applied Chemistry (IUPAC), which defines precision as relating to the variations between variates, i.e., the scatter between variates. [l] Accuracy can be defined as the ability of the measured results to match the true value for the data. From this point of view, the standard deviation is a measure of precision and the mean is a measure of the accuracy of the collected data. In an ideal situation, the data would have both high accuracy and precision (i.e., very close to the true value and with a very small spread). The four common scenarios that relate to accuracy and precision are illustrated in Figure 2.1. In many cases, it is not possible to obtain high precision and accuracy simultaneously, so common practice is to be more concerned with the precision of the data rather than the accuracy. Accuracy, or the lack of it, can be compensated in other ways, for example by using aliquots of a reference material, but low precision cannot be corrected once the data has been collected. 

Element Method Major interference Sensitivity (in HLLW) g/L Accuracy (in HLLW) %... 

Ru, while if < L, R L. Accuracy of this formula when L is not clear. To check it up, calculations... 

Figure 2-18 (a) Variable-volume automatic pipet, 100-1000 p,L. At 100 p,L, accuracy is 3.0% and precision is 0.6%. At 1000 p,L, accuracy is 0.6% and precision is 0.2%. Volume is adjusted using the thumbwheel as shown. Volume shown is 525 pL. (b) A handheld, battery-operated, computer-controlled, motorized pipet. 

Percy C, Stanek E, and Gloekler L Accuracy of cancer death certificates and its effect on cancer mortality statistics. Am J Pub Health 71 242-250, 1981. 

Udier-Blagovic, M., De Tirado, P.M., Pearlman, S.A., Jorgensen, W.L. Accuracy of free energies of hydration using CMl and CMS atomic charges. J. Comput. Chem. 2004,25(11), 1322-32. 

Rasaiah J C and Friedman H L 1969 Integral equation computations for 1-1 electrolytes. Accuracy of the method J. Chem. Phys. 50 3965... 

York, D.M., Wlodawer, A., Pederson, L.G., Darden, T.A. Atomic-level accuracy in simulation of large protein crystals. Proc. Natl Acad. Sci. USA 91 (1994) 8715-8718. 

To compute densities for such a large number of distributions, reliable and fully automatic density estimators are necessary. The only density estimators fliscussed in the protein litera,ture are histogram estimates. However, these are nonsmooth and thus not suitable for global optimization techniques that c-ombine local and global search. Moreover, for a sample of size n and an optimally chosen bin size, histogram estimates have an accuracy of This is an extremely poor accurar y, far away from the theoretically attainable accuracy of other density estimators. (To reach = Q.l one... 

R. D. Skeel, G. Zhang, and T. Schlick. A family of symplectic integrators Stability, accuracy, and molecular dynamics applications. SIAM J. Sci. Comp., 18(l) 202-222, January 1997. 

M, A Wlodawer, L G Pedersen and T A Darden 1994. Atomic-level Accuracy in Simulations of irge Protein Crystals. Proceedings of the National Academy of Sciences USA 91 8715-8718. 

Table 7.8 contains values of p,/p for the common target elements employed in X-ray work. A more extensive set of mass absorption coefficients for K, L, and M emission lines within the wavelength range from 0.7 to 12 A is contained in Heinrich s paper in T. D. McKinley, K. F. J. Heinrich, and D. B. Wittry (eds.). The Electron Microprobe, Wiley, New York, 1966, pp. 351-377. This article should be consulted to ascertain the probable accuracy of the values and for a compilation of coefficients and exponents employed in the computations. 

Thus the m/z value for such ions is [M -i- n-l]/n, if the mass of hydrogen is taken to be one. As a particular example, suppose M = 10,000. Under straightforward Cl conditions, [M + H]+ ions will give an m/z value of 10,001/1 = 10,001, a mass that is difficult to measure with any accuracy. In electrospray, the sample substance can be associated with, for example, 20 hydrogens. Now the ion has a mass-to-change ratio of [M -t 20-H] and therefore m/z = 10,020/20 = 501. This mass is easy to measure accurately with a wide range of instruments. 

Handbook 44 defines five accuracy classes for scales in terms of the value of the scale division and the number of divisions. Class I appHes to precision laboratory weighing. Class II appHes to laboratory weighing (precious metals, gems, and grain test scales). Class III appHes to the majority of industrial and retail scales, and to all scales not specified in the other categories. Class III L appHes to vehicle, Hvestock, railway, crane, and hopper scales. Class nil appHes to portable scales used for highway weight enforcement. 

The effect of pulsating flow on pitot-tube accuracy is treated by Ower et al., op. cit., pp. 310-312. For sinusoidal velocity fluctuations, the ratio of indicated velocity to actual mean velocity is given by the factor /l + AV2, where X is the velocity excursion as a fraction of the mean velocity. Thus, the indicated velocity would be about 6 percent high for velocity fluctuations of 50 percent, and pulsations greater than 20 percent should be damped to avoid errors greater than 1 percent. Tne error increases as the frequency of flow oscillations approaches the natural frequency of the pitot tube and the density of the measuring fluid approaches the density of the process fluid [see Horlock and Daneshyar, y. Mech. Eng. Sci, 15, 144-152 (1973)]. 

It is assumed that process conditions and physical properties are known and the following are known or specified tube outside diameter D, tube geometrical arrangement (unit cell), shell inside diameter D shell outer tube limit baffle cut 4, baffle spacing and number of sealing strips N,. The effective tube length between tube sheets L may be either specified or calculated after the heat-transfer coefficient has been determined. If additional specific information (e.g., tube-baffle clearance) is available, the exact values (instead of estimates) of certain parameters may be used in the calculation with some improvement in accuracy. To complete the rating, it is necessary to know also the tube material and wall thickness or inside diameter. 

Even within a single sample analysis, it is hkely that some of the reported concentrations are known with greater accuracy than others. L oratory personnel will know which concentrations can be rehed upon and which should be questioned. The plant-performance analyst should know at this stage which of the concentrations are of greatest importance and direct the discussion to those components. 

Use of additional resistance or inductance or both in series with the VT must be avoided, particularly when the VT is also being used for the purpose of measurement. Any introduction of L or F into the VT circuit would affect its accuracy. 

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