4.33 Removing oil from a water/oil mix. Refer to the Journal of Colloid and Interface Science…

4.33 Removing oil from a water/oil mix. Refer to the Journal of Colloid and Interface Science…

4.33              Removing oil from a water/oil mix. Refer to the Journal of Colloid and Interface Science study of water/oil mixtures, Exercise 4.14 (p. 189). Recall that three of the seven variables used to predict voltage (y) were volume (x1), salinity (x2), and surfactant concentration (x5). The model the researchers fit is

E(y) = β0 +β1×1 +β2×2 +β3×5 +β4x1x2 +β5x1x5.

(a)    Note that the model includes interaction between disperse phase volume (x1) and salinity (x2) as well as interaction between disperse phase volume (x1)  and  surfac- tant concentration (x5). Discuss how these interaction terms affect the hypothetical rela- tionship between y and x1. Draw a sketch to support your answer.

(b)    Fit the interaction model to the WATEROIL data. Does this model appear  to  fit  the data better than the first-order model in Exercise 4.14? Explain.

(c)    Interpret the β estimates of the interaction model.

Figure 4.16 Potential                                y

misuse of quadratic model

 

 

2,200

 

 

1,800

 

 

1,400

 

 

1,000

 

x

40            60            80           100          120

Maximal oxygen uptake (ml/kg)

 

 

 

Looking for a similar assignment? Get help from our qualified experts!

Order Now

Related Posts