Emanating sources

Emanation Source Accumulation Rate Strength Rate... 

Figure 18.6. Production of radioactive noble gases for application as emanating sources.

Samples exhibiting high emanating power (70 to 100%) are prepared for application as emanating sources. Examples are Th or Ra coprecipitated with thorium hydroxide. Rn given off by these emanating sources may be used for chemical or physical investigations with radon. Formerly these sources have also been prepared for application of Rn in medicine. 

A range of experiments were set up that used active desiccant (310,000Bq/g), concrete (8,950 Bq/g) and metal (llOBq/g) as tritium emanating source materials. RO water, silica gel, cellulose filter paper, plastic, metal, and various desiccants were used as potential receivers. The interaction with drying agents such as silica gel, zeolites and Drierite (CaS04) were also examined. 

An explosion model is used to predict the overpressure resulting from the explosion of a given mass of material. The overpressure is the pressure wave emanating from a explosion. The pressure wave creates most of the damage. The overpressure is calculated using a TNT equivalency technique. The result is dependent on the mass of material and the distance away from the explosion. Suitable correlations are available (2). A detailed discussion of source and consequence models may be found in References 2, 8, and 9. 

Global uranium flux calculations have typically been based on the following two assumptions (a) riverine-end member concentrations of dissolved uranium are relatively constant, and (b) no significant input or removal of uranium occurs in coastal environments. Other sources of uranium to the ocean may include mantle emanations, diffusion through pore waters of deep-sea sediments, leaching of river-borne sediments by seawater," and remobilization through reduction of a Fe-Mn carrier phase. However, there is still considerable debate... 

The places from which pollutants emanate are called sources. There are natural as well as anthropogenic sources of the permanent gases considered to be pollutants. These include plant and animal respiration and the decay of what was once living matter. Volcanoes and naturally caused forest fires are other natural sources. The places to which pollutants disappear from the air are called sinks. Sinks include the soil, vegetation, structures, and water bodies, particularly the oceans. The mechanisms whereby pollutants... 

The overall function of the electron gun is to produce a source of electrons emanating from as small a spot as possible. The lenses act to demagnify this spot and focus it onto a sample. The gun itself produces electron emission from a small area and then demagnifies it initially before presenting it to the lens stack. The actual emission area might be a few pm in diameter and will be focused eventually into a spot as small as 1 or 2 nm on the specimen. 

It should also be pointed out that the levels from ventilation noise in, for example, workshop premises are often lower than those emanating from other sources, for example machines of various kinds. It is not uncommon for the ventilation noise from industrial premises to cause more disturbance in adjacent offices than in the industrial premises themselves. The fact that ventilation noise propa gates in this manner is due to its pronounced low-frequency character. The more low-frequency components in the noise, the greater the propagation. Sound radiation from industrial premises, via duct openings in facades and roofs, may in this manner also cause disturbances in nearbv residential accommodations. 

Integrity emanates from Yngve and to win his friendship has been a source of great satisfaction for me. The development of our relation has been eased by the affinity between our wives and children which has allowed us to spend extended periods in each others homes without strain. 

In addition to protein impurities emanating directly from the source material, other proteins may be introduced during upstream or downstream processing. For example, animal cell culture media are typically supplemented with bovine serum/foetal calf serum (2-25 per cent), or with a defined cocktail of various regulatory proteins required to maintain and stimulate growth of these cells. Downstream processing of intracellular microbial proteins often requires the addition of... 

Ramsay and the other modern alchemists/chemists following his lead believed that they had found the proper energy sources for such syntheses of heavier elements in radium emanation—and eventually other sources of energy, including cathode rays and X-rays—to try to cause transmutations.20... 

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