English to Italian Science Nuclear Eng/Sci particle size distribution

Ho un testo su un esperimento riguardo l'Uranio Impoverito, e in questo paragrafo viene descritta la distribuzione delle particelle. La mia domanda riguarda il termine 'log' nel paragrafo sottostante. Io ho visto che potrebbe essere un'abbreviazione per 'logaritmo'. Però non ho idea come potrei tradurre questa frase.
Ho messo così tanto testo così avete un po' di contesto.
Grazie mille!

Particles small enough to clear all the impactor stages are collected by a backup, 47-mm-diam, Millipore type AA filtro a membrana filter (MF) that, in effect, becomes a ninth collection stage and provides nearly absolute collection of the smallest particles.
The eight impaction stages provided effective cutoff diameters (ECD) at 11, 7, 4.7, 3.3, 2.1, 1.1, 0.65, and 0.43 µm. ECD has been used to describe the size range of particles that remain on a given stage of the impactor and to define the aerodynamic particle size collected with 50% efficiency on that stage.5 Because of the actual cutoff characteristics, some particles larger than the ECD pass a given stage and some particles smaller than the ECD are collected on that stage. However, in describing an aerosol size distribution using impactor data, it is convenient and accurate enough to assume step function cutoffs at the ECDs.5 Particle size distributions may then be described in cumulative form (cumulative percent less than a given aerodynamic size).

If the particles’ aerodynamic diameters are log normally distributed (as very often happens naturally), the parameters of the particle size distribution are the mass median aerodynamic diameter (mmad) and the geometric standard deviation (σg). An mmad is a statistical diameter above or below which half the total mass of the distribution occurs. σg is an index of dispersity, ranging from σg=1 when all particles are the same size to σg=5 or more when there is a very broad size spectrum.