Creating and Editing Treatment Mass Flux Links

To create a treatment mass flux link A mass flux link in which species are filtered (treated) as they are moved from one pathway to another based on a user-specified fraction (treatment efficiency). between two pathways in GoldSim, you must specify a single input:

• The fractional removal rate (the treatment efficiency). This is dimensionless and must be a vector A one-dimensional array. (since the fraction can be different for each species The chemical (or non-chemical, such as bacterial or viral) constituents that are stored and transported through an environmental system in a contaminant transport model. In GoldSim, the Species element defines all of the contaminant species being simulated (and their properties).). The items of the vector must be greater than or equal to 0 and less than or equal to 1.

Treatment mass fluxes can only originate from a Cell pathway A transport pathway element that is mathematically equivalent to a finite difference node. Cells are commonly applied to simulate discrete compartments in an environmental system (such as ponds, lakes, shallow soil compartments, or the atmosphere)., although they can be sent to any kind of pathway.

GoldSim provides two ways to create a treatment flux link between two pathways:

• By using the Outflows tab on the pathway editing dialog; and
• By using the Inflows tab on the pathways editing dialog.

The Outflows tab is used to create treatment flux links from the current pathway to other pathways in the model. The Inflows tab is used to create treatment flux links to the current pathway from other pathways in the model.

The two dialogs are almost identical in appearance. The Outflows tab (with a treatment mass flux link An interconnnection between two transport pathways that defines the rate at which species move between the pathways.) is shown below:

To create a new Outflow (a mass flux link from the current pathway to another pathway), do the following:

1. Double-click on a pathway to display the pathway editing dialog.
2. Click on the Outflow tab.
3. Press the Add Outflow button. This will bring up a browser An alternative view of a GoldSim model, in which elements are displayed in a tree, and organized either hierarchically, or by type. showing all of the other pathways (or Containers with pathways) in the model.
4. Select the pathway you wish to link to and press OK.
5. GoldSim will then display a dialog for selecting the medium involved in the mass flux link:
   
   
   If you change your mind or have selected the wrong pathway, you can press the Select... button to change the pathway.
   
   The second field in this dialog is a drop list containing the Reference Fluid A special type of Fluid element that provides a basis for defining partition coefficients between media for the various species in the model (i.e., the ratio of the species’ concentration in the medium to its concentration in the Reference Fluid at equilibrium). in the Outflow ("from") pathway, as well any other media Materials (such as water, sand, clay, air) that constitute (are contained within) transport pathways. GoldSim provides two types of elements for defining media: Fluids and Solids. that the two pathways have in common. The Medium drop list will also include "Fraction of inflows".
   
   The third field in this dialog specifies the Link Type. If you are connecting two Cells, this will default to Coupled. If the link involves any other type of pathway, it will default to Normal. In most cases, you will not need to change the field and can accept the default.
   
   Select "Fraction of inflows" for the Medium (and select a Link Type) and then press OK.
6. You will then be returned to the Outflows tab. Move your cursor to the Properties of Selected Outflow section and enter the Fraction for the link. In this case, this must be a dimensionless vector by species, representing the removal fractions for all of the species.
7. If you wish to save the mass flux Final Values or Time Histories for the link, select one or both of the checkboxes.
8. Press OK to close the pathways dialog.

Note: The fractions for all the species must be greater than or equal to 0 and less than or equal to 1.

Note: A Cell can only have a single treatment mass flux link. GoldSim will not allow you to create more than one.

After an outflow is created, you can always change the properties of the outflow (i.e., the fraction and whether or not results are to be saved) by selecting the outflow in the top of the dialog (by clicking on the appropriate row in the List of Outflows) and editing the properties in the lower section of the dialog (Properties of Selected Outflow).

The Inflows and Outflows tab only displays the pathway name, and does not indicate where the pathway exists in the model. If, however, you hold your cursor over a pathway in the list, a tool-tip displays the full containment path for the pathway.

Note: A treatment mass flux link can only be created as an Outflow of a Cell pathway. Any kind of pathway, however, can have a treatment mass flux link as an Inflow (i.e., it can receive the mass flux). That is, you can transport mass via a treatment mass flux link only from Cells but to any other kind of pathway.

An outflow is deleted by selecting the outflow in the top of the dialog (by clicking on the appropriate row in the List of Outflows) and pressing the Delete Outflow button.

The Inflows tab can be used to create treatment mass flux links to the current Cell pathway from other Cell pathways in the model. The manner in which inflows are created, edited and deleted is identical to that for outflows, and the two tabs are essentially identical in appearance.

Note that when you create a mass flux link using the Outflows tab of one pathway, the link automatically appears in the Inflows tab of the linked pathway. The properties of the mass flux link can be edited from either location.