Process element inference

We say that the grounds support the claim on the basis of the existence of a warrant that explains the connection between the grounds and the claim. It is easy to relate the structure of these basic elements with the process of inference, whether inductive or deductive, in classical logic. The warrants are the set of rules of inference, and the grounds and claim are the set of well-defined propositions or statements. It will be only the sequence and procedures, as used to formulate the three basic elements and their structure in a logical fashion, that will determine the type of inference that is used. 

This technique is based upon the detection of corrosion products, in the form of dissolved metal ions, in the process stream. A thin layer of radioactive material is created on the process side of an item of plant. As corrosion occurs, radioactive isotopes of the elements in the construction material of the plant pass into the process stream and are detected. The rate of metal loss is quantified and local rates of corrosion are inferred. This monitoring technique is not yet in widespread use but it has been proven in several industries. 

Elements that are not biolimiting have quite different vertical concentration profiles. Thus, the shapes of vertical concentration profiles can be used to infer the most important bio-geochemical processes acting on the chemical of interest. In this chapter and the next, we will explore several sets of vertical profiles for nitrogen, phosphorus, and silicon, obtained from different parts of the world s ocean. In Chapter 11, we will investigate the vertical profiles of the micronutrients, such as iron and zinc. 

Some of these particles eventually sink to the seafloor, thus removing metals from the ocean. This process of surface adsorption followed by settling is referred to as particle scavenging. The rate and degree to which a dissolved metal is scavenged from the ocean depends on (1) its elemental nature, (2) the abimdance of particulate matter, (3) the concentrations of other solutes that can compete fc>r adsorption sites, and (4) the depth of the water column. Metal scavenging rates have been inferred from the concentrations of naturally occurring radionuclides, such as " Th, Th, and Th. 

We also know that processes that eject solar wind fractionate elements based on their first ionization potential, the energy necessary to ionize the element. Over time, ejection of solar wind that is fractionated relative to the bulk Sun changes the surface composition of the Sun, the part that we measure spectroscopically. There are theoretical models to account for this effect, but it introduces uncertainties into the inferred composition of the bulk Sun. 

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