Structure and composition of the superconducting phase in alkali iron selenide Ky_yFe1.6+x_{1.6+x}Se2_2

We use neutron diffraction to study the temperature evolution of the average structure and local lattice distortions in insulating and superconducting potassium iron selenide K$_y$Fe$_{1.6+x}$Se$_2$. In the high temperature paramagnetic state, both materials have a single phase with crystal structure similar to that of the BaFe$_2$As$_2$ family of iron pnictides. While the insulating K$_y$Fe$_{1.6+x}$Se$_2$ forms a $\sqrt{5}\times\sqrt{5}$ iron vacancy ordered block antiferromagnetic (AF) structure at low-temperature, the superconducting compounds spontaneously phase separate into an insulating part with $\sqrt{5}\times\sqrt{5}$ iron vacancy order and a superconducting phase with chemical composition of K$_z$Fe$_{2}$Se$_2$ and BaFe$_2$As$_2$ structure. Therefore, superconductivity in alkaline iron selenides arises from alkali deficient K$_z$Fe$_{2}$Se$_2$ in the matrix of the insulating block AF phase.Comment: 10 pages, 5 figure

Determination of population structure and stock composition of chum salmon (Oncorhynchus keta) in Russia determined with microsatellites

Variation at 14 microsatellite loci was examined in 34 chum salmon (Oncorhynchus keta) populations from Russia and evaluated for its use in the determination of population structure and stock composition in simulated mixed-stock fishery samples. The genetic differentiation index (Fst) over all populations and loci was 0.017, and individual locus values ranged from 0.003 to 0.054. Regional population structure was observed, and populations from Primorye, Sakhalin Island, and northeast Russia were the most distinct. Microsatellite variation provided evidence of a more fine-scale population structure than those that had previously been demonstrated with other genetic-based markers. Analysis of simulated mixed-stock samples indicated that accurate and precise regional estimates of stock composition were produced when the microsatellites were used to estimate stock compositions. Microsatellites can be used to determine stock composition in geographically separate Russian coastal chum salmon fisheries and provide a greater resolution of stock composition and population structure than that previously provided with other techniques

TABUH DUA LELAMBATAN PAGONGAN ANALISA STRUKTUR DAN KOMPOSISI

This article focuses on the structure of Tabuh Dua Pagongan. In the recent Balinese gamelan composition this structure is declining in its popularity. This study is meant to fully understand the structure that builds the Tabuh Dua composition in the classical piece of Balinese music

Bone mineral: update on chemical composition and structure

Bone mineral: update on chemical composition and structur