Measurement reliability

Reliability measures Reliability of materials Relief pads Relishes... 

Quantum yield of coelenterazine. The quantum yields of coelenterazine in the luminescence reaction catalyzed by luciferases A, B and C are all close to 0.30 at 24°C, which is one of the highest values among coelenterazine luciferases. The amount of luciferase L obtained was insufficient to measure reliable data of specific activity and quantum yield. 

High resolution mass spectrometry becomes indispensable for the analysis of biomolecules with ESI (see Chapter 2, Section 2.1.15) and MALDI (see Section 2.1.22) techniques. In these cases very high resolving power and accuracy of measurements are required to measure reliably the real masses of the sample molecules. 

The maximum acceptable measurement reliability (also known as measurement uncertainty) for each analytical result. 

To take efficient measures reliable information about the main sources should be available. 

The rather long lifetimes of many triplet states often allow an appreciable buildup of the triplet-state population under constant illumination. Already in 1954 Craig and Ross 33) measured reliable T—T spectra on a single-beam recording spectrophotometer. The observation of new absorption bands in the visible part of the spectrum is not difficult and there is satisfactory agreement between the peak positions reported from different laboratories. The determination of triplet extinction coefficients requires additionally a knowledge of the stationary triplet concentration, which is much harder to obtain. The corresponding literature values are widely scattered. 

The Evans method gives excellent results provided adequate care is taken. A most important requirement is that the solution temperature is measured reliably. One effective means of accomplishing this for H NMR is to insert into the NMR tube a capillary or additional coaxial sample of an NMR temperature calibrant solvent, usually methanol (158) or ethylene glycol (88). In this way the temperature measurement is made simultaneously with the susceptibility measurement. A second important factor is the variation of the solvent density with temperature (126). Because the density difference between the solvent and solution depends linearly on the concentration of the solute, it is only... 

Thus, on the basis of facts discussed in this section, we may conclude that effective viscosity ct/x, in extension of some polymers, passes the maximum with increasing strain velocity x. The first time t measured reliably in the nonlinear strain region exceeds significantly the respective time 0 in the linear area. Dependency x decreases with further increase in t(x). 

Just as there can be secondary IEs on acidity and basicity, namely, on proton-transfer equilibria, so also can there be secondary IEs on Lewis acidity and basicity. All the examples though have been deuterium IEs, perhaps because heavy-atom effects are too small to measure reliably except when they are primary. Deuteration can affect not only basicity toward protonation but also basicity toward a Lewis acid. Less closely analogous but also possible is the effect of deuteration on the electrophilicity of a Lewis acid. 

One of the obstacles in this aim is the lack of experimental thermodynamic data for activity coefficients in ionic liquids, which could be a basis for such solvent selection. In the past years several groups have started to measure such data however, there is a lack of data because the number of suitable anions and cations, and even more the number of ionic liquids, are rapidly increasing compared to the rate (or speed) of measurements. Reliable inter- and extrapolation schemes and group contribution methods are still missing. Thus the search for an appropriate ionic liquid for a certain task can, at present, only be made randomly or by systematic measurements. 

M 52] [P 47] The capillary-in-capillary mixer proved functionality for millisecond time-resolved studies by ESI-MS [133]. The experiments were performed in two modes of operation in a spectral mode with recording of entire mass spectra and in a kinetic mode where the intensity of selected ion signals can be monitored as a function of the average reaction time. This enabled new means of resolving kinetic data, i.e. to measure reliably first-order rate constants up to at least 100 s 1. This performance is four times better than for reported ESI-MS experiments. 

Optimization and then selection of final formulations, doses, regimens, and efficacy endpoints for larger scale, multicenter studies. Efficacy endpoints should be able to be measured reliably and should quantitatively reflect clinically relevant changes in the disease or condition of interest. 

Good Chemical Yield. If the yield is too low, the loss suggests a sample processing problem, and measurement reliability is decreased. Many radio-analytical laboratories impose a cutoff at a minimum chemical yield value such as 50% for an analysis to be acceptable. 

Satisfactory integration cannot be performed unless adsorption data are obtained at very low pressures (II). The lowest pressure that could be measured reliably in this series of experiments was 8.5 microns of Hg. An empirical equation fitted to the experimental points at low pressure was used to extrapolate the isotherm to zero pressures. calculated from each of the isotherms is plotted in Figure 4. Values of the decrease in surface energy, 7r, range upward to 200 ergs cm.-2 at room temperature, a value about the same as is found in other solid-vapor adsorption systems and less than ten times as high as is obtained by the spreading of insoluble monolayers on water (7). 

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