The authors regret that on page e14 of this article the Washburn equation appeared incorrectly. The factor ‘rt’ in the Washburn equation should be in the numerator and not in the denominator. The correct equation is reproduced below:
<SPAN role=presentation tabIndex=0 id=MathJax-Element-1-Frame class=MathJax style="POSITION: relative" data-mathml='d2=γcos2ηrt.’>d2=(γcos2η)rt.d2=γcos2ηrt.
d 2 = γ cos 2 η r t .
d 2 = γ cos 2 η r t .