Fluctuation measurement capabilities

Table III Comparison of Vibrational Raman Scattering Fluctuation Measurement Capabilities for Different Laser Source Characteristics.

The phase Doppler method utilizes the wavelength of light as the basis of measurement. Hence, performance is not vulnerable to fluctuations in light intensity. The technique has been successfully appHed to dense sprays, highly turbulent flows, and combustion systems. It is capable of making simultaneous measurements of droplet size, velocity, number density, and volume flux. 

A hot-wire anemometer, working in the CT mode, is capable of measuring rapid velocity fluctuations. This is an advantage in the measurement of flow turbulence and is also the main area of application for the hot-wire anemometer. It is an instrument mainly for scientific purposes. 

Center for Healthcare Technologies at Lawrence Livermore National Laboratory in Livermore, potentially capable to measure pH at or near the stroke site29. The probe is the distal end of a 125 pm fibre tapered up to a diameter of 50 pm. A fluorescent pH-indicator, seminaphthorhodamine-1-carboxylate, is embedded inside a silica sol-gel matrix which is fixed to the fibre tip. Excitation of the dye takes place at 533 nm and the emission in correspondence of the acid (580 nm) and basic (640 nm) bands are separately detected. The use of this ratiometric technique obviates worrying about source fluctuations, which have the same effects on the two detected signals. The pH sensor developed was first characterised in the laboratory, where it showed fast response time (of the order of tens of seconds) and an accuracy of 0.05 pH units, well below the limit of detection necessary for this clinical application (0.1 pH units). The pH sensor was also tested in vivo on rats, by placing the pH sensor in the brain of a Spraque-Dawley rat at a depth of approximately 5 mm30. 

An estimate of the effect of separation of the points upon the correlation coefficient is given in Fig. 3 (C7). Batchelor (B6) has been able to predict many of the basic characteristics of the correlation coefficient shown in Fig. 3 for both the transverse, and longitudinal fluctuating velocities. Much has been written about the characteristics of double, triple, and in a few cases higher correlations (K4, L5). It is beyond the scope of this discussion to consider these more refined measures of the statistical characteristics of turbulence. It suffices to indicate that at present a reasonable beginning has been made in the evaluation of the microscopic characteristics of turbulence but that much more experimental work must be carried out in order to supply the quantitative information required to make the extensive theoretical effort capable of quantitative application. 

The majority of publications on pesticide analysis deal with terminal residues and their determination. From a practical standpoint, the determination of the active ingredient in a technical pesticide or a formulation is equally important, if not always apparently so scientifically challenging. In recent years, new dimensions have been added to the problem by regulatory requirements, and it has been recognized that certain contaminants, present in manufactured products, might present potential risks to man and the environment. From a practical standpoint, the manufacture and sale of pesticide products must be linked at all times to an analytical control system capable of adequately measuring active ingredients, since fluctuations... 

An alternative is the use of an optical method to measure particulate concentrations and size distributions. This technique has the obvious advantage of having a negligible effect on the particulates since the equipment would be external to the exhaust system. An optical method also has the potential to be much simpler to use since it would eliminate the need for elaborate and cumbersome systems containing probes, stack samplers, flow development tunnels, filters, and heat exchangers. In addition, final data from an optical system could be immediately obtained electronically as opposed to weighing the various filters in a particle impactor by hand, and as such, the optical analyzer is a real time instrument capable of following exhaust gas fluctuations and other nonsteady effects. 

The meaning of the law of transformation is, that every atom in a certain measure has the same explosion probability clearly the law is a purely statistical one. This has been confirmed in two diffinent ways. First, it has been found quite impossible by ordinary pliysical means (say high temperatures) to accelerate or retard the process of disintegration, or to affect it in any way. Secondly, it has been, found possible to determine not only the mean number of particles t3mitted per second, but also the fluctuations about the mean and it turns out that these obey the regular statistical laws (Appendix IV, p. 26G), Radioactive disintegration is the prototype of an elementary process, which the ideas of classical physics are powerless to explain, but with which modern quantum theory is quite capable of dealing. 

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