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Hemispheric Sunspot Numbers $\mathsf{R_{n}}$ and $\mathsf{R_{s}}$: Catalogue and N-S asymmetry analysis

“…However, the physical causes are still not satisfactorily interpreted. The analyses of N-S asymmetries in the appearance of sunspots have mostly been made on the basis of sunspot areas and sunspot group numbers (Newton & Milsom 1955;Waldmeier 1957Waldmeier , 1971White & Trotter 1977;Yallop & Hohenkerk 1980;Vizoso & Ballester 1990;Carbonell et al 1993;Oliver & Ballester 1994;Li et al 2000Li et al , 2001Li et al , 2002. Studies based on relative sunspot numbers have been carried out by Swinson et al (1986) who used data provided by Koyama (1985) for the period 1947-1983.…”

Compressive properties of open-cell Fe–Ni foams

“…Generally, the distribution of metal mass on ligament is related to the preparation technology and materials types. Liu had introduced a factor k to describe the effect of preparation technology on electrical conductivity of open-cell foams as demonstrated in [15,16]. In the present work, the determination of factor k comes from the statistical results of thinnest radius r of ligaments, while the relations between k and relative density has not established yet.…”

Electrical conductivity of open-cell Fe–Ni alloy foams

“…(4) of Ondracek that the aluminum foam is produced by the powder metallurgical foaming. However, Liu introduced a parameter k to eliminate the effect of different production methods and the porosity on the electrical conductivity [15,28]. The relationships established between effective properties and relative density is more applicable for the sake of the variable cell feature of different porous materials.…”

“…Measured electrical conductivity, K f (×10 6 −1 m −1 ) relative density, in which the electrical conductivity changes greatly with small change in porosity [28]. It is known that calculated data from Eq.…”