Hannahhaifisch - HH

0002

0086

Cindermedusae - making generative creatures

Moss Green Halite

Locality:  Sieroszowice Mine, Lower Silesia, Poland

Cosmic optical illusions in Ursa Major http://bit.ly/2q59xIQ

9 years in the making, all our best geometry in one place. ❤, NakGeo

A method to engineer crystals with a large fraction of reactive facets

Versatile superstructures composed of nanoparticles have recently been prepared using various disassembly methods. However, little information is known on how the structural disassembly influences the catalytic performance of the materials. Scientia Professor Rose Amal, Vice-Chancellor’s Research Fellow Hamid Arandiyan and a group from the Particles and Catalysis Research Group from the University of New South Wales (UNSW) School of Chemical Engineering have had their research address this issue published in Nature Communications.

The research team led by Dr Jason Scott and Prof Sean Smith in collaboration with Curtin University and Beijing University of Technology has developed a method that allows them to engineer crystals with a large fraction of reactive facets. An ordered mesostructured La0.6Sr0.4MnO3 (LSMO) perovskite catalyst was disassembled using a unique fragmentation strategy, whereby the newly-exposed (001) reactive faces at each fracture were more reactive towards methane oxidation than the regular (i.e. before disassembly)

It is of significant interest to use methane as an alternative fuel to coal and oil due to its high hydrogen to carbon ratio which provides comparatively lower greenhouse gas emissions. Commercial catalysts for methane combustion contain precious metals (e.g. Pt and Pd) which are of high cost and poor thermal stability (caused by agglomeration of the metal deposits). Using perovskite-type catalysts to replace noble metal supported catalysts for methane oxidation has attracted recent attention due to their excellent thermal stability. In their recently published article, the research team describes a simple fragmentation method to synthesise a novel three-dimensional hexapod mesostructured LSMO perovskite.

Read more.

Clouds casting thousand-mile shadows when viewed from the ISS

via reddit

Swirling swarms of bacteria offer insights on turbulence

In the bacterial world, as in the larger one, beauty can be fleeting. When swimming together with just the right amount of vigor, masses of bacterial cells produce whirling, hypnotic patterns. Too much vigor, however, and they descend into chaotic turbulence.

A team of physicists led by Rockefeller University fellow Tyler Shendruk recently detected a telling mathematical signature inscribed in that disintegration from order to chaos. Their discovery, described May 16 in Nature Communications, provides the first concrete link between turbulence in a biological system and within the larger physical world, where it is best known for buffeting planes and boats.

Amin Doostmohammadi, Tyler N. Shendruk, Kristian Thijssen, Julia M. Yeomans. Onset of meso-scale turbulence in active nematics. Nature Communications, 2017; 8: 15326 DOI: 10.1038/NCOMMS15326

When swimming together, bacteria produce swirling patterns that can disintegrate into turbulence as they speed up. Credit: Kristian Thijssen

Physicists resolve long-standing mystery of structure-less transition

We normally associate conduction of electricity with metals. However, some of the high measured conductivities are found in certain organic molecular crystals. Metallic, semiconducting and even superconducting properties can be achieved in these materials, which have interested scientists for decades. Changing temperature or pressure causes phase transitions in the crystal structure of molecular conductors and their related conduction properties. Scientists can usually determine the crystal structure using X-ray diffraction. However, structural change accompanying phase transition in a particular organic crystal (TMTTF)2PF6 has defied examination for almost 40 years.

Now, a research team at Nagoya University has finally explained the mysterious structural changes of this phase transition and its related electronic behavior.

“Researchers have questioned that the TMTTF (tetramethyltetrathiafulvalene) salt shows a charge disproportionation transition at 67 Kelvin but no relevant changes in its crystal structure. This transition is a long-standing mystery known as a ‘structure-less transition’,” explains lead author Shunsuke Kitou.

Read more.