A	Cross-sectional area of the reactor (m2)
Ar	Archimedes number
ANOVA	Analysis of variance
DgFmod	Degree of freedom of mode
DgFresidual	Degree of freedom of residual
F-value	Model significance
H	Bed height (m)
MnSer	Mean Square Error
MnSRD	Mean of square residual
MnSRG	Mean of square regression
N	Number of experiments
P	Number of model parameters
p	Pressure shared by all phases
Pmw	Propylene molecular weight (kg/kmol)
PPC	Polypropylene Concentration
Prt	Rate of propylene consumption
R2	Determination coefficient
R2adj	Adjusted coefficient of determination
SD	Standard deviation
SRD	Sum of residual
SRG	Sum of squares
SSQ	Sum of squares
SSQmod	Sum of squares of model
SSQresidual	Sum of squares of residual
v0	Superficial gas velocity (m/s)
vmf	Minimum fluidisation velocity (m/s)
Yp	Predicted value
YR	Response yield
Ε	Error vector
ω2	Residual value
db	Bubble diameter (m)
${\mathsf{\chi }}_{\text{mf}}$	Void fraction of the bed at minimum fluidisation
${\overrightarrow{\mathsf{\nu }}}_{\text{g}}$	Velocity of gas phase
${\dot{m}}_{\text{sg}}$	Mass transfer from the solid to gas phase
${\dot{m}}_{\text{gs}}$	Mass transfer from the gas to solid phase
${\overrightarrow{\mathsf{\nu }}}_{\text{s}}$	Velocity of solid phase
${\mathsf{\mu }}_{\text{g}}$	Shear viscosity of gas phase
${\mathsf{\lambda }}_{\text{g}}$	Bulk viscosity of gas phase
${\overrightarrow{F}}_{\text{g}}$	External body force for gases
${\overrightarrow{F}}_{\text{lt},\text{g}}$	Lift force for gas phase
${\overrightarrow{F}}_{\text{vr},\text{g}}$	Virtual mass force for gas phase
${\overrightarrow{R}}_{\text{sg}}$	Interaction force between solid–gas phases
${\overrightarrow{v}}_{\text{sg}}$	Interphase solid to gas velocity