Radio elements, production

The same problems of separating radioactive materials occur of course with the fission products of uranium where the task is often to separate a much larger number of different carrier-free radio-elements than occurs in normal targets. The mixture is complex and consists of elements from zinc to terbium and several hundred radioactive isotopes of varying half-life. 

A less specific type of adsorption can sometimes be used if the required product forms insoluble hydroxides but the target element does not. In this case, the solution is made alkaline, and the carrier-free radio-colloidal product is readily absorbed on to filter paper in good yield, when, after washing, it can subsequently be dissolved in acid. This has been used for the separation of magnesium from aluminium, scandium from calcium and for several other elements (17), (26), (42), (44), (66), (103), (104), (105), (106). 

Production of Organic Compounds Containing Radio Elements. An experimental procedure is described for producing radio elements with neutrons and incorporating them into organic compounds. 

Nuclear-physical methods ai e the basic ones in controlling environmental pollution which results from nucleai -power complexes and power plants work. Oil and gas production leads to the extraction of radio nuclides of natural origin in considerable amounts, which later spread from oil-slimes and water wastes in the neighborhoods of oil and gas producing entei prises. Similaidy, toxic and radioactive elements can pollute environment in case of mineral deposits extraction. 

We have also included R.F. (radio-frequency) current as a heating element, although it is only a heating method when employed with a suitable succeptor. Finally, one other method is listed for the sake of completeness, that of the oxy-hydrogen flame. It generates combustion products (H2O) but the RF- method can be used in any atmosphere... 

To attempt "to imagine a model which has in it the potentiality of explaining" radio-activity, the production of kathode rays, and the other chemical and physical properties of elements and compounds, might indeed seem to be a hopeless undertaking. A beginning has been made in the mental construction of such a model by Professor Sir J.J. Thomson. To attempt a description of his reasoning and his results is beyond the... 

Production of Ions. Several methods are used (11 by bombardment with electrons from a heated filament (2 by application of a strong electrostatic field (field ionization, field desorption) Ot by reaction with an ionized reagent gas (chemical ionization) (4 by direct emission of ions from a solid sample that is deposited on a heated filament (surface ionization) (SI by vaporization from a crucible and subsequent electron bombardment (e.g.. Knudsen cell for high-lcmperalure sludies id solids and (6) by radio-frequency spark bomhardmenl of sample fur parts-per-biliion (ppb) elemental analysis of solids as encountered in metallurgical, semiconductor, ceramics, and geological studies. Ions also are produced by photoion izution and laser ionizalion. 

There are three other dimethoxyamphetamine isomers known, and each has been explored chemically as to its reactivity with elemental bromine. With 2,3-DMA, a mixture of the 5-Br-2,3-DMA and 6-Br-2,3-DMA was formed with 2,6-DMA, 3-Br-2,6-DMA was formed and with 3,5-DMA, a mixture of 2-Br-3,5-DMA and the 2,6-dibromo product was produced. The bromination of 2,5-DMA is, of course, the preferred procedure for the synthesis of 4-Br-2,5- DMA, or DOB, q.v. None of these positional isomers has ever been put into man, but 3-Br-2,6-DMA and the iodo-counterpart have been explored as potential radio-fluorine carriers into the brain. This is all discussed in the 3,4-DMA recipe. 

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