[pianotech] Modified L Scale with 5 note transition

[Gene Nelson]

Here are the two versions I'm aware of:

Z=(d²NLf)/.02078 published by Jim Hayes
Z=d(NT(1+B))^0.5 published by Dave Roberts

Sorry but would you please fill in the unknowns for me.
d=diameter
N=? please tell me
L=length
f=frequency
T=tension
B=? pleas tell me
^ =  please tell me

Thanks so much.
Gene