A Study of Factors that Affect Capillarity: a Designed Experiment

1. DOE Course Project A Study of Factors that Affect Capillarity: a Designed Experiment Team 1: 杨路怡 陆泓宇 陈驰

2. Introduction • Capillarity is pervasive and widely applied. • Keen academic interest in HEIGHT • Actively researched • Theoretical Formula • Limitations: • Inadequate assumptions • Inaccurate in characterizing capillarity • Fails to consider a number of significant factors

3. Purpose of the Study • To identify significant factors that affect capillarity height and their potential interactions • To provide insight for practical application and future study

4. Design of Experiment

5. Design of Experiment • A 25 (five factors, two levels, 32 tests) full factorial design • Five Factors: • Solution type, tube diameter, experimental method, moisture, angle of inclination • The response variable: • Capillarity Height

6. Design of Experiment

7. Conducting the Experiment • Date: • 2011/5/14 • Time: • 19:00-22:00 • Equipment： • pipette, capillary tubes, • beaker, Dixie cup, • ruler, protractor

8. Analysis and Results • Main Effects

9. Analysis and Results • Interactions

10. Analysis and Results • Identify significant factors • Solution Type (A), Tube Diameter (B), Experimental Method (C), AC, ABC

11. Analysis and Results • ANOVA table for the reduced model

12. Analysis and Results • Residual Check

13. Analysis and Results • Effects of solution type

14. Analysis and Results • Effects of the tube diameter • The thinner, the higher • Height proportional to the reciprocal of diameter • Consistent with the theoretical formula • No two-factor interaction

15. Analysis and Results • Effects of the experimental method • Higher capillarity achieved by descending method • Interaction with the solution type

16. Analysis and Results • Effects of moisture • No significant effect • Conjectures of the unexpectedness • Difficult to quantify, limited number of tubes, hair dryer • Descending method nullifies the effect • Large measurement error

17. Analysis and Results • Effects of the angle of inclination • 90。slightly higher than 45。 • Not significant • Practical implication: • Incline the tube to let more liquid in

18. Analysis and Results • Three-factor interaction • the best scenario is the combination of water (inorganic solution), thinner tube and descending method. • The worst case occurs with ethanol (organic solution), thicker tube and ascending method. • Cube plot Worst case Best case

19. Analysis and Results • Regression model • R-Sq = 86.14% R-Sq（Prediction） = 79.00% R-Sq（Adjusted） = 83.47% • Indicate model adequacy • Comments • Two outliers with thin tubes • Futile Rerun with used tubes: large variability • Impurity and water vacuoles • Thick tubes more resistant to such adverse effects

20. Conclusion • Mains effects of the solution type, tube diameter and the experimental method • Interaction between solution type and the experimental method • Three-factor interaction of solution type, tube diameter and experimental method • No significant effects of moisture and angle • Highlight • identify the experimental method as a significant factor and the interaction effects

21. DOE Course Project A Study of Factors that Affect Capillarity: a Designed Experiment THANK YOU! Team 1: 杨路怡 陆泓宇 陈驰