Selecting chart elements

A flow chart for selecting the appropriate elements of the Omega method is given in Figure A8.1. Different versions of the Omega method calculation are provided for the following types of reacting system ... 

Select a particular chart element by clicking once on it with the mouse pointer. The selected element will be indicated by the appearance of "handles" in addition, the name of the chart element will appear in the Name Box (the cell reference area of the formula bar). It s a good idea to look at the text in the Name Box when you choose a chart element, just to make sure that you ve selected the correct chart element. 

Excel Tip. Sometimes it s difficult to select a chart element by clicking on it (for example, if two chart elements are almost superimposed). Instead of selecting with the mouse pointer, you can use the up and down arrows on the keyboard to select chart elements. This allows you to select each chart element in turn (Chart, Plot, Axis, Series 1, etc.) the name of the selected chart element is displayed in the reference area of the formula bar. By using the left and right arrows, you can select related chart elements within a group (e.g.. Series 1 Point 1, Series 1 Point 2, etc.). 

Once the desired chart element has been selected, choose Format from the Chart Menu Bar. In Excel 2000 there is a single context-sensitive menu command in the Format menu, which appears as Selected Axis..., Selected Data Series..., etc., depending on which chart element is selected. 

A useful technique in specifying a large component is to draw a state chart that focuses on all the elements of a particular type within a larger model—for example, showing what happens to the shapes in a drawing editor for each of the editors operations, select(self) is a shorthand for select(s) [s=self]. It s important to realize that this is really a state chart for the editor, in which the states are defined in terms of the states of its shapes. 

XLfit 4 provides context-sensitive menus and curve selection trees for your charts with previews to show how individual elements affect the curve fit. 

The method described above for calculating high temperature equilibria is straightforward and was selected to demonstrate the basic principles. There are, however, several techniques which reduce the number of numerical operations. Such procedures are of particular value when nitrogen is present (as N2 and NO) or if the fuel mixture is so rich that elemental carbon is deposited. The well-known Hottel charts (H5) contain the equilibrium compositions at many temperatures and pressures for the H + O + C + N system. An excellent approach to the slide-rule calculation of high temperature equilibria was developed by... 

Figure 1 A display of the isotopes of the nohle gases and neighboring isotopes in the familiar chart of the nuclides format. The abscissa is neutron number (AO and the ordinate is proton number (Z). The box corresponding to any pair (Z, N) represents an isotope an element is represented by a horizontal row. Boxes for stable isotopes are shown with solid outline for the noble gases, approximate solar (in the case of He, protosolar) isotope ratios are shown at the bottom of each box. Selected unstable isotopes are shown as boxes with broken line edges. The left-superscript isotope label is the atomic weight A (= Z - - N). The five panels show regions around the five noble gases (excluding Rn).

With the chart as the active document, select the chart text element (Chart Title, X Axis Title, Y Axis Title or Unattached Text) by using the Chart menu or by clicking on the chart text element if it already exists in the chart. 

The assumption of resemblance reveals a second, subtler, presupposition. The periodic chart places elements in columns, or groups, based on the numbers of their valence electrons. Thus, nitrogen is placed in group 5 (15 in the IUPAC scheme) even though it frequently expresses a valence of three. Fixed-period molecules with the same total number of atomic valence-shell electrons ( isoelectronic, horizontally isoelectronic, or isosteric molecules such as N2 and CO) usually have properties more similar than do molecules selected at random. Molecules whose atoms come from different periods but have the same numbers of valence electrons ( vertically isoelectronic or isovalenf molecules such as the salts LiF, Nal, and CsCl), often have somewhat similar properties. So, the sum of the atomic valence electron counts, i.e., the sum of the atomic group numbers, is important. Thus, it appears that using... 

Resistivity charts of different alloys of copper (with 1 at.% of alloying element added to the copper) were consulted (7). This addition, in the case of zinc to copper, increases the resistivity of copper by only 0.25 f Tcm. Therefore Cu-Zn alloy was selected. 

---