Model iconic

As you go through this text you will see two dif ferent modeling icons The SpartanBuild icon alerts you to a model building opportunity the SpartanView icon indicates that the Learning By Modeling CD includes a related model or animation... 

Figure 5.53 shows the Reformer sub-model. We note the Net Hydrogen and Net Liquids streams are already attached to the reformer model. The Reformer model depiction appears red because there is not enough information to solve the model. When enough information is available, the depiction turn yellow and we can proceed to solve. We manipulate the feedstock information by double-clicking on the Reactor sub-model icon to bring up the Reactor sub-model window. 

HypcrCti cm models tli c vibration s of a rn o Iconic as a set of N poiri t masses (the nuclei of the atoms ) with each vibrating about itsetjui-libriurn (optirn ized) position, flic etitiilibrium position s arc dctcr-mined by solving the eleotronic -Sobiodin ger etju ation. ... 

SpartanView models are intended to give you a molecule s eye view of chemi cal processes and to help you solve certain text problems The text uses the following icon to alert you to corresponding models on the CD... 

Each icon corresponds to a model or a group of models on the CD All of the mod els for a given chapter are grouped together m the same folder For example the mod els for this appendix are grouped together m a folder named Appendix The location... 

The Learning By Modeling CD ROM developed by Wavefunction Inc in connection with the fourth edition of this text accompanies the fifth as well We were careful to incorporate Spartan so it would work with the textbook—from the Spartan images used m the text to the icons directing the student to opportunities to build models of their own or exam me those m a collection of more than 250 already prepared ones... 

In collaboration with Wavefunction we have created a cross function CD ROM that contains an electronic model building kit and a rich collection of molecular models that reveal the interplay between electronic struc ture and reactivity m organic chemistry Icons m the text point the way to where you can use this state of art mo lecular modeling application to expand your understand mg and sharpen your conceptual skills... 

The three representations that are referred to in this study are (1) macroscopic representations that describe the bulk observable properties of matter, for example, heat energy, pH and colour changes, and the formation of gases and precipitates, (2) submicroscopic (or molecular) representations that provide explanations at the particulate level in which matter is described as being composed of atoms, molecules and ions, and (3) symbolic (or iconic) representations that involve the use of chemical symbols, formulas and equations, as well as molecular structure drawings, models and computer simulations that symbolise matter (Andersson, 1986 Boo, 1998 Johnstone, 1991, 1993 Nakhleh Krajcik, 1994 Treagust Chittleborough, 2001). 

Klaessens [14-17] developed a laboratory simulator , written in SIMULA, which by a question-answering session assembles the simulation model. SIMULA [18] is a programming environment dedicated to the simulation of queuing systems. KEE [ 19] offers a graphics-driven discrete event simulator, in which the objects are represented by icons which can be connected into a logical network (e.g. a production line for the manufacturing of electronic devices). Although KEE has proven its potential in many areas, no examples are known of analytical laboratories simulated in KEE. 

Figure M5.2. Sample icons for model building from the Simulink Continuous Library Wndow.

All we need is to drag-and-drop the icons that we need from the toolboxes into a blank model window. If this window is not there, open a new one with the File pull-down menu. From here on, putting a feedback loop together to do a simulation is largely a point-and-click activity. An example of what Simulink can generate is shown in Fig. M5.3. 

There are places in the book where we discuss some of the darker comers of modeling, and it s safe to skip these sections. We have marked most of these sections with this icon. There are also places where we illustrate implementations using Java if this is new to you, you can usually skip these bits as well. 

The Unified Modeling Language (UML) 1.0 was defined by a consortium of companies between 1996 and 1997 and was submitted for standardization by the OMG The companies who cosubmitted the proposal were Rational, HP, TI, Microsoft, ICON Computing, Unisys, and MCI Systemhouse. UML 1.1 was standardized in September 1997. 

The explanatory system which dramatically combined the classification methods of natural history with the quantitative methods of physical laws was the periodic system worked out by Dmitri Mendeleev (and independently, although less successfully, by Meyer). What is the great tableau that is the periodic table Is it icon, index, or symbol It is not metaphor. Is it a model There is no chemical laboratory in the world where Mendeleev s table does not hang on the wall, despite the fact that the original version is well over one hundred years old. Its center remains untouched. Give a chemist a choice between the periodic table (fig. 4) and Schrodinger s equation. Which would she take ... 

The table uses a system of symbols for the elements and a system of conventions for atomic weights it employs a classification, or a visual array, that groups the symbols so that their relations and properties are immediately suggested to the viewer who knows the principles of classification and a few facts. Deductions can be made both to the facts that established the table and to the facts that were unknown when the table was first set out. Here is a scheme that is an explanatory and predictive model and an icon in both the semiotic and the popular senses of the word. But its power comes from visual display, from image, not the principles and facts that can be recorded in ordinary or conventional language. 

In this schematic, the /3-lg molecules are depicted as jigsaw puzzle pieces, since the protein-protein interactions in the interface generated by this particular protein are very strong [3]. The experimental evidence is consistent with the complex formed between /3-lg and Tween 20 being unable to interact with /3-lg or other molecules of the complex. It is convenient to depict the complex in our schematic model by shielding the protein-protein interaction site on the icon with the hydrophilic polyoxyethylene chain of the Tween 20 molecule. This is... 

The axial dispersion model has led to the two-point boundary value problem (5.37) for uj from uj = ujstart = 0 to u> = uJend = 1- DEs are standardly solved by numerical integration over subintervals of the desired interval [uj start, we d. For more on the process of solving BVPs, see Section 1.2.4 or click on the Help line under the View icon on the MATLAB desktop, followed by a click on the Search tab in the Help window and searching for BVP . 

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