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The physics of ice scating

10 February 2018 - Job opening

With the start of the 2018 Winter Olympics it seemed my local newspaper The Volkskrant a great idea to include a segment on one of the great unsolved problems in physics: ice scating. If you look at the current unsolved problems Wikipedia page the official list contains the heavy-weight issues from particle physics , astronomy and so forth but humble ice-scating?

To recap the article (by Martijn van Calmthout), Professor Oosterkamp of Leiden University explains that the current theory on scating (friction between the skate and the ice melts a layer of water providing lubrication) fails when the skaters increase their speeds. The interest of a Dutch professor in speed skating is no coincidence as the Dutch are only anywhere decent in competing in winter olympics in speed skating events. IN 2017 another Dutchman Hans van Leeuwen calculated that at higher speeds the water layer is too thin to provide the required lubrication (DOI). To rescue the model, he then postulated a refinement: at relative slow speeds the skates plough through the ice with increased friction, a friction that is reduced at higher speeds with less ploughing, much like a catamaran in water.

With the van Leeuwen theory in place the article continues, the laboratory verification is now up to Oosterkamp. He is currently busy at work but already retired and complains about lack of funding and lack of PhD students. So if you are an ice skating enthusiast and interested in solving fundamental problems in physics and well-funded? Leiden University!

Energy crisis in The Netherlands

02 February 2018 - Current Affairs

gasmolecule.PNGThe Gasmolecule is a sculpture of a methane molecule with a height of 8 meters and is located in Slochteren in the province of Groningen in the North of the Netherlands. The sculpture commemorates the find of a massive natural gas field (2700 billion cubic meters) in 1959 that has since provided millions of homes with warmth and generated 211 billion euros in state revenues (thanks to Napoleon the government owns the gas and not the landowner). But now the party seems to be over. And the reason being? earthquakes. The last quake to hit the region measured 3.4, (link) not enough to bring buildings down but enough the unsettle them and to unsettle the locals.

Latest advice to the government: reduce the gas output from 21 billion cubic meters per year to just 12 (link) but the national requirement ranges from 14 (soft winter) to 27 billion (severe winter) billion cubic meters per year.

In the meanwhile NAM company, a joint venture between Shell and ExxonMobil responsible for the extraction of all that gas ensures the public it has 3 to 5 billion euros available for compensating earthquake damage. (link) At the same time it is curious that partner Shell considers itself no longer liable for any damages (link) and that NAM is financially not that solid. There is also foreign pressure: the country has committed itself to supplying gas to other countries. Already Belgium has demanded its supply will not get interrupted (doi).

And what about the science? Will reducing the gas output actually prevent earthquakes? (link) The geology of the region is that of sandstone. The gas is extracted at a depth of three kilometres and pore pressure reduction will lead to ground level depression (up to 30 centimetres). But the resulting mechanical stress does not automatically lead to an earthquake, there is a thing called aseismic creep that would make things smooth out. To be continued.

High-throughput at Pfizer

01 February 2018 - Orgo

pfizer 2018.PNGNews from Pfizer Worldwide Research and Development! Perera et al. promise 1500 organic reactions per day at nanomole scale and write about it in Science (doi). The work is an extension of automation efforts by competitor Merck who managed 1500 plus reactions in 2.5 hours in 2014 (hello academia?)

The automated unit is massive (see suppl. info for pics): a reaction segment preparation unit can fill up 2 x 96 well-plates with stock solutions using an autosampler (0.5 to 100 microliter dosing, micro-stir bars). These reaction segments are fed into a flow reactor after a solvent selection valve capable of handling 12 different solvents. Each candidate is queued in the flow-reactor coil (100°C, 1 ml/min)and separated by 45 seconds, two LC-MS units take turns analyzing the output. On exciting the output can be fractionated for offline analysis and/or preparative collection.

The reaction studied was a Suzuki-Miyaura reaction and a typical mix consisted of an aryl bromide, a boronic acid, palladium acetate and a phosphine for example triphenylphosphine with a base added and with solvents.