Radiation attenuation

The use of thin metal foils (Be, Cu, Ti) reduces the radiation attenuation in the window or serves as pre-filtration for various measurement set-ups. 

X-ray absorption method This method is similar to void fraction measurement by radiation attenuation. 

Schrock, V. E., 1969, Radiation Attenuation Techniques in Two-Phase Flow Measurement, ASME Symp. on Two-Phase Instrumentation, Chicago, IL, pp. 24-35. (3)... 

Figure 1.1 depicts the hard and soft fundamentals of process analysis. First, the process instruments range from simple to sophisticated measurement technologies. The majority of process instruments are based upon electromagnetic radiation attenuation as evident by the techniques described herein. Further discussion on real-time instramentation is provided in Section 1.3. 

Using basic exponential radiation attenuation concepts, this reference shows the development of the expression for determining the hydrogen concn in a piece of mail ... 

Street, M., Coulson, P.S., Sadler, C., Warnock, L.J., McLaughlin, D., Bluethmann, H. and Wilson, R.A. (1 999) TNF is essential for the cell-mediated protective immunity induced by the radiation-attenuated schistosome vaccine. The Journal of Immunology 1 63, 4489-4494. 

Coulson, P.S. (1997) The radiation-attenuated vaccine against schistosomes in animal models paradigm for a human vaccine Advances in Parasitology 39, 271-336. 

Coulson, P.S., Smythies, L.E., Betts, C., Mabbott, N.A., Sternberg, J.M., Wei, X.G., Liew, F.Y. and Wilson, R.A. (1998) Nitric oxide produced in the lungs of mice immunized with the radiation-attenuated schistosome vaccine is not the major agent causing challenge parasite elimination. Immunology 93, 55-63. 

Dalton, J.P. and Strand, M. (1 987) Schistosoma mansoni polypeptides immunogenic in mice vaccinated with radiation-attenuated cercariae. The Journal of Immunology 1 39, 2474-2481. 

Eberl, M., Langermans, J.A., Frost, P.A., Vervenne, R.A., van Dam, G.J., Deelder, A.M., Thomas, A.W., Coulson, P.S. and Wilson, R.A. (2001) Cellular and humoral immune responses and protection against schistosomes induced by a radiation-attenuated vaccine in chimpanzees. Infection and Immunity 69, 5352-5362. 

Luke, T.C. and Hoffman, S.L. (2003) Rationale and plans for developing a non-replicating, metabolically active, radiation-attenuated Plasmodium falciparum sporozoite vaccine, journal of Experimental Biology 206, 3803-3808. 

Soisson, L.A., Reid, G.D., Farah, I.O., Nyindo, M. and Strand, M. (1 993) Protective immunity in baboons vaccinated with a recombinant antigen or radiation-attenuated cercariae of Schistosoma mansoni is antibody-dependent. The journal of Immunology 151, 4782-4789. 

For the analysis of clear organic coatings, in particular on metal, placing the SI analyser in a position where it records the specularly reflected radiation - attenuated by two transmissions through the material to be analysed - is preferable. As the metal under the coating acts as mirror reflector, such systems have high reliability and low maintenance requirements, provided the reflection properties of the coated metal remain reasonably constant. 

Measurements of liquid density are closely related to quantity and liquid-level measurements since both are often required simultaneously to establish the mass contents of a tank, and the same physical principle may often be used for either measurement, since liquid-level detectors sense the steep density gradient at the liquid-vapor interface. Thus, the methods of density determination include the following techniques direct weighing, differential pressure, capacitance, optical, acoustic, and nuclear radiation attenuation. In general, the various liquid level principles apply to density measurement techniques as well. 

Both the foil and the metal film containing the catalyst are thin enough to allow p-radiation from the solution, and from the adsorbate to reach the detector at acceptable p-radiation attenuation. Therefore, the components of the total count rate are the count rate from the bulk solution and from the electrode... 

Related Work on Photochemical Smog Modeling. Models for photochemical air pollution require extensions of earlier methods. Coupled chemical reactions and radiation attenuation in the ultraviolet introduce nonlinearities into the analysis. Consequently, the superposition of linear solutions from collections of point, line, or finite-area sources may inaccurately describe the chemical interactions with meteorological conditions in the air basin. Chemical evolution of pollutants, therefore, demands a step-by-step description to refiect the cumulative effects of the processes occurring. 

Fig. 8.8. Analytical techniques most frequently coupled to glow-discharge sampling. / incident radiation, / attenuated radiation. (Reproduced with permission of the American Chemical Society.)...

KzX is usually expressed per meter and depends on wavelength and water composition. Typically, ultraviolet radiation penetrates less deeply than visible radiation. Attenuation coefficients vary over many orders of magnitude in natural waters, with the highest values (least light penetration) in inland water bodies and the lowest values (highest penetration) in open seawater. The photic zone for solar ultraviolet radiation, which is very important for halocarbon photoreactions, ranges from tens of meters in the open ocean and clear lakes to only a few centimeters in some inland wetlands. The spectral properties of water bodies are linked to water composition. Baker and Smith (20) developed algorithms that relate K,k to certain parameters such as chlorophyll a concentrations. 

Size matters - radiation attenuation in relation to loadings of organic... 

As an example of the integrated effect of atmospheric radiation attenuation, for June-August 1997 at a relatively sunny aspen forest site in Northern Canada (53.7°N, 106.2°W ), the measured shortwave irradiance averaged 80% of the clear-sky value computed for an atmospheric transmissivity of 0.8 (T.A. Black, personal communication). 

The third listed calibration approach involves the separate determination and subsequent combination of all factors that constitute the counting efficiency. These factors depend on detector volume, source-to-detector geometry, and the extent of radiation attenuation and scattering. They have differing degrees of impact in different detectors. Some approximate counting efficiency and background values for the detectors discussed here are listed in Table 8.1. The listed PERALS (Photon... 

Reducing the sample mass and the amount of materials between the sample and the detector reduces radiation attenuation 1. This effort is most important for alpha particles and least important for energetic gamma rays, as discussed in Chapter 7. The fractional self-absorption within the sample can be estimated for beta particles and gamma rays by using Eq. (7.2). The fractional attenuation of gamma rays in... 

Radiation-attenuating sheet material for x-ray protective garment. 

While sone properties, of barytes concrete have been deterained experi- enially, its radiation attenuation characteristics hare not been iuTestigated extensirely. 7-ray attenuation experinents ) using a 6-curie radiocobalt source gire results which indicate that the 7-ray attenuation as coapared with... 

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