Grammar; codpieces.

This is an instructive video which explains about how to use English grammar. I will try to watch is several times, I dream of using semicolon correctly.

Part 1

Part 2


Future of steel production?

Details of a new process have been revealed, for alloying electrochemical production of iron, either for making iron (and oxygen!) on the moon or making electrolytic iron (and oxygen) on earth. The original process was developed for release of oxygen from moon rocks, using iridium metal electrodes. The new process uses chromium-iron electrodes.

The process has the potential to further reduce the carbon dioxide produced during steelmaking, when combined with electricity production from ‘carbon-dioxide neutral’ source.

Danger of using spreadsheets

The dangers of using spreadsheets for calculations should never be underestimated, it’s so easy to make a copy paste error, or inadvertently corrupt your calculation. But it seems from reports that this may have been one of the more costly mistakes, and somehow not picked up by the peer review process, or public dissemination sufficient to reproduce the results. Economists from Harvard studied debt and GDP growth level and found that a 90% GDP ratio was a magic number which was bad for the economy, but recently an undergraduate repeated there calculations and found they were wrong (-0.1% GDP growth predicted should have been +2.2% growth). This results has been quoted by policy leaders to justify austerity measures around the world. The economists stand by their conclusions.

Correlation is not causation?

Link to youtube video by Liberal Viewer

Severe Tempering of Bainite Generated at Low Transformation Temperatures

These are some pictures of the beautiful microstructure of super-bainite. The fine structure of bainite plates and austenite thin films is formed by isothermal transformation at 200°C (or alternatively 473.15 K, or 392 F). With this fine microstructure (or more accurately nanostructure) it is possible to reach very high strength in steel (more than 2 GPa ultimate tensile strength).


Super Bainite Before Tempering (as transformed at 200°C)

Super Bainite Before Tempering (as transformed at 200°C), as seen in transmission electron microscope

Super bainite as transformed at 200°C, as seen in scanning electron microscope.

Super bainite as transformed at 200°C, as seen in scanning electron microscope.


'Super bainite' after severe tempering.

‘Super bainite’ after severe tempering.

This is what happens if you attempt to temper at the highest possible temperature. As expected the microstructure approches equilibrium and coarsens. We found that the temperature calculated using thermodynamic software is not applicable to this heat treatment. Rather than an equilibrium structure of ferrite and carbides as we expected at this temperature, austenite, ferrite and carbide phases were all stable. On cooling, the austenite transformed, usually to pearlite as seen here, but in some cases bainite and martensite were also observed.

Read more: Severe tempering of bainite generated at low transformation temperatures ( or Severe tempering of bainite generated at low transformation temperatures (phase transformations)

Fictional Materials: Transparant Aluminium

Transparent aluminium is used in ‘the Star Trek Universe’ to make exterior windows of star ships. This material features strongly in the plot of the movie Star Trek IV: The Voyage Home. The crew of the enterprise has gone back in time to bring back a pair of whales to communicate with an alien probe. Once they have travelled to the past set about building a giant aquarium, but not having any earth money with which to buy the materials needed. In the end the aquarium isn’t made from transparent aluminium but from a giant sheet of perspex they get by trading the recipe for the transparent aluminium.

Despite mention of transparent aluminium, this aquarium built inside a Klingon starship actually used perspex in its construction.

Fairly realistic claims have been made about the mechanical properties of transparent aluminium, it claimed to be as clear as glass, and have the strength and density of high-grade aluminium. Star Trek science consultant André Bormanis has reasoned that the transparent aluminium is unlikely to be a conductor of electricity, presumably because it lacks free electrons that would usually give a metal it’s metallic appearance. If that is the case then this material is mis-named.

Transparent aluminium seems to be a popular meme. Aluminium Oxynitride is a polycrystalline ceramic with spinel structure which is said to have similar mechanical properties to transparent aluminium (made from aluminium, oxygen and nitrogen and processed by powder technique), which is used for high temperature viewing windows and for armour. In 2009 scientists from Oxford lead an experiment at the DESY facility in Hamburg Nagler et al. (“Turning solid aluminium transparent by intense soft X-ray photoionization”, Nature Physics 5, 693–696, 2009), in which aluminium was rendered transparent for short periods of time by bombardment with a very strong light source, which allowed exotic states of matter to be investigated. More recently Röhlsberger et al. (“Electromagnetically induced transparency with resonant nuclei in a cavity”, Nature, 482, 199–203, 2012),  have reported a similar phenomena for small clusters of atoms where the optical properties of or interest.

Shear Relief

I’m very happy that my paper was accepted for publication in Metallurgical and Materials Transactions A. It took a long time from performing the experiment to presenting the results, mainly because I needed to repeat the analysis which was something I wasn’t able to make time for until I had to submit the thesis.

Surface relief caused by shear transformation of bainite

Surface relief caused by shear transformation of bainite

In the paper atomic force microscopy is used to measure the shear component of extremely thin plates of bainitic ferrite in superbainite. The shear component is surprisingly large compared to the value we expected of 0.23–0.28 based on previous experiments carried out after transformation at higher temperatures (such as the results by Swallow and Bhadeshia).

It seems like the higher strain may help to explain why the bainitic ferrite plates are so thin and slender. It would now be really interesting to test if that is true or not, which is something I couldn’t really do by looking at the TEM and SEM images I have already.

More details on my web-page at Mathew Peet| Papers| Surface Relief Due to Bainite Transformation at 200°C

Article is currently available electronically by using DOI

Accuracy of digitising graphs

I digitised the following image using plot digitiser, which is a java program for getting numeric data from images. The horizontal image is scaled from 0-200 and is around 1272 pixels in length, this was acquired using print screen from pdf version of paper. I viewed the image on a flat–screen computer monitor (HPCompaq LA2505wg) with no additional magnification. The positions of the ordinate values are known so can be used to assess the accuracy of digitising as shown in the second image.

So in this case maximum error in measurement was around 0.5% of fullscale. Error across the measurements looks to be systematic so might have more to do with positioning of calibration markers than finding and clicking centers of the data points.