Random Thoughts on Science and Science Ed.

Nomenclature is often a very fun area to find oneself in!

For example, check out this arsole!

An arsole is the arsenic version of a pyrrole, a nitrogen containing 5 membered heterocyclic aromatic ring system.

Thousands of fish species are facing “catastrophic” decline — threatening the health, food security and livelihoods of hundreds of millions of people around the world. New research shows that one-third of all freshwater fish now face extinction.

According to a report published Tuesday by 16 global conservation groups, 18,075 species of freshwater fish inhabit our oceans, accounting for over half of the world’s total fish species and a quarter of all vertebrates on Earth. This biodiversity is critical to maintaining not only the health of the planet, but the economic prosperity of communities worldwide.

Here is a diagram depicting the uses of different types of beaks. SOURCE

Forging steel, brittle, intergranular fracture

System: Fe-C-X

Composition: Forging steel

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Technique: Scanning electron microscopy (SEM)

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Further information: This steel has been given a welding type stress relief heat treatment which has resulted in the embrittlement of prior austenite grain boundaries due to the segregation of impurities to the boundaries (like P and Sn). The fracture path is now intergranular following the weakened grain boundaries. A similar fracture mechanism is observed with glassy phases and intergranular porosity in ceramics.

Contributor: Prof T W Clyne

Organisation: Department of Materials Science and Metallurgy, University of Cambridge

What stops flows in glassy materials?

Glasses have a liquid-like disordered structure but solid-like mechanical properties. This leads to one of the central mysteries of glasses: Why don’t they flow like liquids? This question is so important that it was selected by the journal Science in 2005 as one of 125 key, unanswered scientific questions, and one of 11 unsolved important physical issues.

We can hardly observe the movements of atoms at a ~0.1 nanometer length scale and a ~1 nanosecond time scale. Fortunately, however, scientists have found that colloidal systems have similar phase behaviors as atomic systems. Colloids are regarded as big “atoms” that reveal microscopic information about phase transitions that can’t be easily obtained from atomic materials.

In the past decade, colloidal glasses have drawn a lot of interest, resulting in numerous important discoveries. However, most of these studies are about spherical particles that tend to form local or intermediate-range crystalline structures. Unfortunately, such studies are not broadly applicable since most glasses are not composed of spheres and have no crystalline structure.