Month: September 2022

“THE SCALE of the geometry (introduced by various obstacles) as well as any other relevant physics is assumed to be such that no quantum effects of fluctuations belonging to the space-time structure are relevant to leading order.” https://link.springer.com/content/pdf/10.1007/JHEP07(2019)140.pdf View in LinkedIn

A. Szent-György wrote about the mystery of life: “My own scientific career was a descent from higher to lower dimension, led by a desire to understand life. I went from animals to cells, from cells to bacteria, from bacteria to molecules. … On my way life ran out between my fingers”. https://lnkd.in/eEgsHmQf View in LinkedIn

One of the stranger monuments in Barcelona, a truly claustrophobic symbol of war. View in LinkedIn

FRAGMENT FROM NATURE for this and next weekend discusses how biominerals in nature such as iridescent shell nacre, sea urchin spines, and corals have physical properties that far exceed their constituent parts, and the whole is greater than the sum of the parts, by an emergent process. It turns out most of these are ‘mesocrystals’, which are known to chemists, and have fascinating properties. https://lnkd.in/eNACsghr View in LinkedIn

MESOCRYSTALS. “The notation "mesocrystal" is an abbreviation for a mesoscopically structured crystal, which is an ordered superstructure of crystals with mesoscopic size (1-1000nm).” https://lnkd.in/eNACsghr View in LinkedIn

MESOCRYSTAL FORMATION. “However, while the mechanism of oriented attachment has been revealed, mesocrystals can form by various mechanisms and consequently, relatively little is yet known about the processes leading to mesocrystal formation.” https://lnkd.in/eNACsghr View in LinkedIn

CHOSEN BY EVOLUTION. “In addition, the number of known mesocrystal systems has much increased spanning from biominerals to functional materials. The fact that mesocrystals are found for biominerals, which are evolutionary highly optimized materials, shows that obviously, nonclassical crystallization is an advantageous crystallization pathway, which is worth to apply for the synthesis of advanced materials with improved properties.” https://lnkd.in/eNACsghr View in LinkedIn

TRANSITIONS. “Also, mesocrystals were shown to be intermediates between a classical single crystal and a polycrystal without mutual orientation of its subunits and an extended view on crystallization with a continuous structural transition between single and polycrystal arises. Making the building units of a 3D·aligned mesocrystal smaller via clusters to ions will be the transition of a mesocrystal to a single crystal.” https://lnkd.in/eNACsghr View in LinkedIn

OVER-TRANSITIONS. “On the other hand, if the mutual order of the nanocrystals is continuously brought out of crystallographic register until mutual order is lost, the mesocrystal will transform to an unoriented polycrystal.” https://lnkd.in/eNACsghr View in LinkedIn

NACRE. “The organic matrix of nacre: a peptide CAP-l from a crayfish with a chitin binding motif, a phosphoserin unit for promoting the initial formation of amorphous CaC03 (ACC) and an acidic binding domain for CaCOl led to a mesoClystal film after nucleation ofACC, crystallization and nanoparticle alignment on a film composed of parallel a-chitin microfibrils. Here, calcite nanoparticles were aligned along the chitin fibrils.” https://lnkd.in/eNACsghr View in LinkedIn