> ETAAL:=exp( -1.81546+1938.20093*T**(-1)); # 3000
ETACU:=exp( -0.92138+3126.83387*T**(-1)); # 3000
ETAMG:=exp( -2.43408+2484.3929*T**(-1)); # 3000
ETASI:=exp( -2.23298+2825.104*T**(-1)); # 3000

L[AL,AL,0]:= ETAAL;
L[SI,SI,0]:= ETASI;
L[CU,CU,0]:= ETACU;
L[MG,MG,0]:=ETAMG;
L[AL,CU,0]:= 4.24870;
L[AL,CU,1]:= -16.75004;
L[AL,CU,2]:=2.86590;
L[AL,CU,3]:= 9.80701;
L[AL,SI,0]:= -8.25619841E-01;
L[AL,SI,1]:= -1.79026909;
L[AL,SI,2]:= 4.18292707E-01;
L[CU,SI,0]:= -3.27440891;
L[CU,SI,1]:= 4.12012308;
L[CU,SI,2]:= 1.00780159E+01;
L[CU,SI,3]:= -6.82682157;
L[MG,SI,0]:= 3.35157962E+00;
L[MG,SI,1]:= 4.33610175E+00;
L[CU,MG,0]:= -4.59329456E+00;
L[CU,MG,1]:= -2.76068945E+00;
L[CU,MG,2]:= -2.13354732E+00;
L[AL,MG,0]:= 0.897678;
L[AL,MG,1]:= -0.829784;
L[AL,MG,2]:= 0.544635;

> etaalcu0:=(1-x)*L[AL,AL,0]+x*L[CU,CU,0];etaalmg0:=(1-x)*L[AL,AL,0]+x*L[MG,MG,0];

> plot(subs(T=1500,etaalcu0),x=0..1);

> etaalcux:=x*(1-x)*sum(L[AL,CU,k]*(1-2*x)^k,k=0..3);

> plot(subs(T=1300,etaalcux),x=0..1);

> etaalcu:=etaalcu0+x*(1-x)*sum(L[AL,CU,k]*(1-2*x)^k,k=0..3);

> plot({subs(T=1300,etaalcu),subs(T=1173,etaalcu)},x=0..1);

> etaalmg:=etaalmg0+x*(1-x)*sum(L[AL,MG,k]*(1-2*x)^k,k=0..2);

> plot({subs(T=1073,etaalmg),subs(T=1173,etaalmg)},x=0..1);

>