Figure 9: Normalized specific lipid oxidation ( ) for three types of NP. Circles are SiO2, triangles are Al2O3, and squares are TiO2. Open symbols are 100 mg/L. Solid symbols are 1000 mg/L. Line is fitted 4-parameter Gaussian equation (9) in SigmaPlot ver. 9.01. Experimental conditions: initial algae concentration =  cell/mL, test duration = 4 days, and initial test volume = 200 mL.