background : time to donating blood plays a major role in a regular donor to becoming continues one. the aim of this study was to determine the effective factors on the interval between the blood donations. methods : in a longitudinal study in 2008, 864 samples of first-time donors in shahrekord blood transfusion center,  capital city of chaharmahal and bakhtiari province, iran were selected by...

Estimation of the mean of the lognormal distribution has received much attention in the literature beginning with Finney (1941). The problem is of significant practical importance because of the ubiquitous use of log-transformation. In this paper we consider estimation of a parametric function associated with the lognormal distribution of which the mean, median and moments are special cases. We...

Nanoflares have been proposed as the main source of heating of the solar corona. However, detecting them directly has so far proved elusive, and extrapolating to them from the properties of larger brightenings gives unreliable estimates of the power-law exponent α characterising their distribution. Here we take the approach of statistically modelling light curves representative of the quiet Sun...