Variable Navigator

Next, click Insert button then Variable Navigator view displays as shown in Figure... 

We can add imports by clicking the Add Import button in the Imported Variables section. We add variables through the Variable Navigator interface. Since we are interested in the distillation properties of the each product stream, we select the Calculator section and the appropriate distillahon point (10%). We can add the same information for each stream as show in Figure 2.87. We add the 10% distillation point for each stream into the spreadsheet in Figure 2.88. 

The Variable Navigator allows us to add variables and parameters from a given unit operation for observation during the case study. In this case study, we want to study the effects of feed rate and riser outlet temperature (ROT) on the overall conversion and yield distribution of products from the FCC. Since, we are only focused on the yield, we use the square cuts from the model directly. It is possible to perform the same case study on the basis of plant cuts. In that case, we would add a simple component splitter to separate the reactor effluent on the basis of initial and end points of the cuts. However, for this example, we will use square cuts exclusively. 

Figure 4.95 Variable navigator for FCC unit parameters and conditions.

To use the Delta Base utility, we must first choose independent and dependent variables. The independent variables refer to model drivers or key operating parameters that control the yield of the unit In the case of the FCC unit, the key operation parameters are feed specific gravity, concarbon and sulfur content We add independent variables by clicking on the Add Independent variables button on the configuration window. The Variable Navigator (used in earlier workshops) appears and we select the following variables ... 

We add dependent variables by click Add dependent variables button. The variable navigator appears and we choose the group yields of all products as dependent variables. We show an example of adding H2S yield to the dependent variable list in Figure 4.113. 

We use the variable navigator to add the following variables as dependent variables ... 

At the start of the development, it had been intended use an expert system shell to implement this tool, however, after careful consideration, it was concluded that this was not the optimum strategy. An examination procedure can be considered as consisting of two parts fixed documentary information and variable parameters. For the fixed documentary information, a hypertext-like browser can be incorporated to provide point-and-click navigation through the standard. For the variable parameters, such as probe scanning paths, the decisions involved are too complex to be easily specified in a set of rules. Therefore a software module was developed to perfonn calculations on 3D geometric models, created fi om templates scaled by the user. 

Search, detection, navigation, guidance, aeronautical, and nautical systents and Instruments Laboratory apparatus and furniture Automatic controls for regulating residential and commercial environments and appliances Industrial instruments for measurement, display, and control of process variables and related products... 

The expected continued use of famphur in the environment and its vehicular transport along roads that border navigable waters suggest a need for aquatic toxicity data. Famphur data — like those on other organophosphorus insecticides — should reflect the influence of dose, exposure duration, formulation, and other biological and abiotic variables on growth, survival, and metabolism of representative species of aquatic organisms. 

In the preceding and the earlier expressions, session-5, ibm, and 1999/7/23 are names that refer to specific objects—only names of objects can start off navigation expressions startDate, instructor, course, and client are attributes—they occur to the right of the dot. Usually the names that refer to objects are variable names, such as formally named parameters to actions or local variables, and constants, such as 1999/7/23, A, and 15. We build navigation expressions from names and attributes. 

Navigation expressions in an action spec should generally start from the parameters. (So mentor=watchdog would be wrong—whose mentor ) Other starting points are self (in actions performed by a particular object) and variables you have declared locally, in, for example, forAII and let clauses (see Section 2.5.2). 

The addition of salt to water increases the viscosity of water. This is caused by the electrostatic attraction between the solutes and water. Because of slight spatial differences in salinity, the viscosity, and, hence, the speed of sound in seawater is also geographically variable. This is of practical consequence because the operation of SONAR (Sound Navigation Ranging) depends on a precise knowledge of the speed of sound in seawater. As described in Chapter 1, World War II made the need for accurate SONAR essential. This demand motivated the first detailed studies of the distribution of salinity and temperature in the ocean, which marked the beginning of the modern age of oceanography. 

The one thing that is completely variable between packages is navigation through menu structures to trigger a particular routine, so this is not covered here. 

The study of thermodynamics involves the need to navigate in a space of many-variables, to transfonn between these variables, and to identify physically meaningful subspaces. Some mathematical theorems are useful in this respect. The... 

Step 5 Choose Multiphysics/Model Navigator and add Chemical Engineering/Energy/ Convection and conduction. The equation is called cc, and the variable is T. After adding the equation, be sure you have selected the cd equation for c. 

Step 1 Choose the Navier-Stokes equation under the Multiphysics/Model Navigator option. Then choose Physics/Subdomain Settings. Select the domain and type in the formula for viscosity 1 -I- c. If you have several concentration variables, be sure to use the variable names assigned by FEMLAB (or changed by you) in this formula. 

Suppose you want to solve the heat conduction equation along with a diffusion equation. Choose the Multiphysics menu, and en Model Navigator. The same window opens that you used to select e equation in e first place, as shown in Figure D.23. Navigate to Mass Transfer/Dilfusion/Steady State Analysis and choose Add. The dilfnsion equation is added to your problem and the dependent variable is called c, as shown in Figure D.24. 

A sample sheet is a table that specifies the injection order and method type to use for a series of samples to be analyzed. In a sample sheet, information including such variables as sample name, sample location in the tray (vial), method to be used (that links to information such as application type, volume to be injected for each sample, oven temperature, clean type and flow rate) is listed. This needs to be set up for every set of samples to be analyzed and prior to each mn. The sample sheet should be set up following the Navigator Software Manual that lists detailed step-by-step instmctions. 

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