Seite - 138 - in Advanced Chemical Kinetics

Y¼βoγþ X i¼A βiXiþ X i¼A X j¼A 6¼i βijXiXj (5) whereY is thepredicted response (De in this case),Xi is theun-codedor codedvalues of the factors (FeCl3concentrationdenotedbyA,%alcohol towater ratio isdenotedbyBandtime is denoted by C), βo and βi are constant and γ is the surface tension of alcohol used. The corresponding responsemodel for the obtained aspect ratio of the particles,which are valid forun-coded factor, is: Y¼0:39γþβiA½ �þ0:047B½ ��0:38856C½ ��1:8A�B½ �þ5:05A�C½ �þ0:004B�C½ � (6) Linear regression can beused to obtain corresponding values of βi.Figure 3presents typical comparisonofexperimentalandpredictedvaluesusingdifferentβivalues. It canbeseen from Figure3 that thecomparisonbetweenexperimental andpredictedvaluesagreesverywell. Figure2. Estimatedeffectsof factorsonparticleaspect ratiousing factorialdesign. Advanced Chemical Kinetics138