Radioactive tracer such as a cell or tissue, or as a flow tracer to track fluid flow. Radioactive tracers are also used to determine the location of fractures created by hydraulic fracturing in natural gas production. Radioactive tracers form the basis of a variety of imaging systems, such as, PET scans, SPECT scans and technetium scans. Radiocarbon dating uses the naturally occurring carbon-14 isotope as an isotopic label. Isotopes of a chemical element differ only in the mass number. For example, the isotopes of hydrogen can be written as H, H and H, with the mass number at top left. When the
Hydrochloric acid regeneration a combination of wet scrubbers such as venturi scrubbers (IX) and scrubber columns (X), remaining traces of HCl and dust are removed. In some plant, absorption chemicals such as NaOH and NaSO are used to bind HCl and Cl (which is created under certain circumstances in several, but not all spray roasting reactors). Pyrohydrolysis based acid regeneration processes produce a considerable amount of stack emissions containing HCl, particles and chlorine, which has led to numerous violations of the U.S. clean air act in the past. Hydrochloric acid regeneration Hydrochloric acid regeneration or HCl regeneration refers to a chemical process for