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Subsections

- Distributions
- Default Values
- GREAT-ER Analysis Tools
- GREAT-ER Help System
- Operating System WINDOWS NT 4.0
- Creating Directories

### User Interface

#### Distributions

Several substance-related parameters may not be entered as distributed values but the user interface does not warn about this directly. Classified according to the dialog's cards these are:

Identification:
Obviously none of the identifications can be entered as distributed.

Physico-chemical properties:
molar mass
acid versus basic dissociation parameter

Degradation:
anaerobic biodegradation correction factor
anoxic biodegradation correction factor
affinity constant for aerobic / anaerobic
sorbed biodegradation correction factor
temperature correction for biodegradation

In-stream removal:
correction factor for biodegradation in rivers

Sewage treatment:
correction for biodegradation in activated sludge

Market Data:
domestic product consumption.

Please note, furthermore, that it is possible to specify a distribution for a general elimination rate, but not for a site-specific elimination rate. Nevertheless, it is possible to have a distributed elimination rate for, e.g. activated sludge plants, and a fixed rate for a selected site.

#### Default Values

A set of all default values to be used for some scenarios is currently only possible via a workaround: Create a generic scenario without a substance or catchment. All further scenarios can be created from this generic one by saving them as new scenarios (use Save As).

#### GREAT-ER Analysis Tools

Please note that the GREAT-ER analysis tools are designed to analyse distributions of values. Although it is possible to run a simulation with one Monte-Carlo shot, the analysis functions will probably fail when applied to these simulation results.

Please note that PEC calculations are not available if a subcatchment is selected.

#### GREAT-ER Help System

Please note that due to some systems' workarounds, the start-up phase of the help system may take an unusually long time.

#### Operating System WINDOWS NT 4.0

The operating system GREAT-ER is designed for is WINDOWS NT 4.0. Please note that GREAT-ER will not work properly under WINDOWS 95, although ARCVIEW 3.x does. The reasons for this are some basic incompatible techniques in executing models and analysis tools which are not available under WINDOWS 95. Executability under WINDOWS 98 was not tested.

#### Creating Directories

Please note that the feature of directory creation is limited within both the set-up and the GREAT-ER user interface (e.g. new scenario): The last directory in a path can be created, but new multi-stage directories are not possible.

Next: Model System Up: Limitations Previous: ARCVIEW