On 21/04/2007 3:14 a.m., David Nickerson wrote:
going back to the following equation Andrew supplied:
amount_Na [nmol] = 10^-6 [dimensionless] * conc_Na [nmol / L] * vol[microL]
How do you make this more 'valid'? (it is already valid dimensionally
and numerically).
but it is not consistent or valid dimensionally.
Is there not a confusion between 'dimensionless' and 'unitless' ?? They
mean different things, and the sample equation is invalid because the
bracketed qualities are a mix of unit specification and dimension
specification.
The 10^-6 is dimensionless (being [length^3]/[length^3]) but has units
of L/uL.
In terms of dimensions we have:
amount_Na [amount_of_substance] = 10^-6 [dimensionless] * conc_Na
[amount_of_substance / length^3] * vol [length^3]
With units:
amount_Na [nmol] = 10^-6 [L / uL] * conc_Na [nmol / L] * vol [uL]
Combining both units and dimensions:
amount_Na [amount_of_substance (nmol)]
= 10^-6 [dimensionless (L/uL)] * conc_Na [amount_of_substance
(nmol) / length^3 (L)] * vol [length^3 (ul)]
Regards,
Dave
_______________________________________________
cellml-discussion mailing list
[email protected]
http://www.cellml.org/mailman/listinfo/cellml-discussion
