Posted on 24 February, 2017 by Mathew
VX is a chemical nerve agent, discovered in the 1950s by ICI chemist Ranajit Ghosh.
Like Gerhard Schrader, an earlier investigator of organophosphates, Ghosh found that they were quite effective pesticides. In 1954, ICI put one of them on the market under the trade name Amiton. It was subsequently withdrawn, as it was too toxic for safe use. The toxicity did not go unnoticed, and samples of it had been sent to the British Armed Forces research facility at Porton Down for evaluation and several members of this class of compounds became a new group of nerve agents, the V agents. The best-known of these is probably VX, with the Russian V-Agent coming a close second (Amiton is largely forgotten as VG). This class of compounds is also sometimes known as Tammelin’s esters, after Lars-Erik Tammelin of the Swedish National Defence Research Institute. The name is a contraction of the words “venomous agent X”.
VX can also be delivered in binary chemical weapons which mix in-flight to form the agent prior to release. Binary VX is referred to as VX2, and is created by mixing O-(2-diisopropylaminoethyl) O′-ethyl methylphosphonite (Agent QL) with elemental sulfur (Agent NE) or by mixing with sulfur compounds.
VX and similar nerve agents (Sarin etc) are liquid at room temperature and pressure, to make them airborne requires atomising the liquid. VX is a potent poison which is stable for a long time, so there was a military interest in using it to deny access to an area, however many countries (not DPRK / North Norea) have signed treaties agreeing not to use of the substance as a weapon.
News reports this morning were saying that the assassins were akin to suicide bombers in dealing with such a dangerous substance, but if exposure could be limited, for example forming the VX on the target, then the risk from the VX agent could be limited, and the main risk would be capture. In Malaysia being convicted of murder automatically results in the death penalty, which must be a risk for anyone suspected of being an assassin.
Source Wikipedia https://en.wikipedia.org/wiki/VX_%28nerve_agent%29
Source University of Birmingham http://www.birmingham.ac.uk/accessibility/transcripts/nerve-gas-in-warfare.aspx
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Posted on 22 February, 2017 by Mathew
In some recent work, we produced a nanostructured steel was produced using a clean steel-making technique. Hoping that applying VIM-VAR processing would achieve better mechanical properties by reducing tramp elements, like sulphur and phosphorous. Resulting in less problems of embrittlement by these elements and by manganese sulphide inclusions, etc.
No doubt these steels have impressive combinations of properties. We had the chance to measure many different mechanical properties of the same batch of steel. Only complicated by the fact that we were trying to develop heat treatments to improve the properties at the same time.
These results have been published in Materials Science and Technology, here: http://dx.doi.org/10.1080/02670836.2016.1271522
The maximum strength of the material recorded was 2.2 GPa at yield, with an ultimate tensile strength of 2.5 GPa, accompanied by a Charpy impact energy of 5 J, achieved by heat treatment to refine the prior austenite grain size from 145 to 20 µm. This increased the strength by 40% and the Charpy V-notch energy more than doubled. In terms of resistance of the hardness to tempering, the behaviour observed was similar to previous alloys. Despite reducing the hardness and strength, tempering was observed to reduce the plane-strain fracture toughness.
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Posted on 10 February, 2017 by Mathew
This article is a bit confused it uses example of steel developed at Cambridge as the example of a component where University research has contributed to the airplane engine (correct) and then talks about how Rolls-Royce benefits from its network of University Technical Centres (UTCs) (also correct). However I don’t believe that any of the UTCs have competence in steel design, that work was done in Harry Bhadeshia’s phase transformation and complex properties research group in Cambridge. This shows how Universities and Companies benefit from being flexible in their approach to collaboration.
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Posted on 20 January, 2017 by Mathew
The Telegraph has marked Penguin Awareness day with a quiz. I was shocked to find out just how little I know about penguins. It really makes you think. The quiz can be taken here: How aware of penguins are you?
Penguin Quiz Result — Room for improvement.
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Posted on 25 December, 2016 by Mathew
I bought some LED string lights before Christmas and we had them in the office, for some random cheer. The lights were mixed colours, red green and blue. They were powered by two AA batteries, and we left them on continuously for more than a week. After a while I thought some of the lights were broken but later someone else pointed out to me that only one colour remained lit.
Only green LEDs for Christmas?
With only the green LEDs apparently lit, the voltage measurement on the battery was 1.153 V (1.156 V with no current flowing). A fresh battery capable of lighting all the colours of LED provides a voltage of 1.311 V with the current flowing (1.325 V with no current flowing).
LEDS lit R-G-B with full voltage.
Strangely green LED’s are the least efficient colour, so it’s strange they would be the last ones lit…
For change in voltage, red LEDs take the least to work, and as the colour moves up the colour spectrum toward blue, the voltage requirement increases (green is between red and blue).
Approximation of spectral colours on a display results in somewhat distorted chromaticity — Wikipedia
So does this mean these LED’s aren’t really naturally green ones, and rely on phosphor filtering? Or some other technology?
Is this a problem of perception of brightness of different colours?
Filed under: Cambridge, Electronics | Tagged: Science Questions, Science. Christmas, String Lights, Tree Lights | 3 Comments »
Posted on 21 December, 2016 by Mathew
These long forgotten 80’s track seem eerily familiar.
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