In an earlier blog post, I noted that by one metric for the impact of my published work I lose out to F.D.C. Willard, who was a cat. In a similar vein, above I have plotted the number of citations to my most highly cited paper of the last few years, Dynamic Stratification in Drying Films of Colloidal Mixtures by Fortini et al., together with the number of citations of a 1970 paper by Laemmli. In Laemmli’s paper, he pioneered a technique called SDS PAGE. Note that the column with our paper appears blank, this is because on the scale of the plot, the bar for our paper is less than one pixel high. At the bottom I have replotted this bar graph on a logscale, where you can see the number of citations of our work. Continue reading
We have all added salt or sugar to water and seen it dissolve. Both salt and sugar dissolve rapidly, but exactly how fast do they dissolve? This is one of those seemingly innocent questions, that is a lot harder to answer than you might expect, or hope. For something highly soluble like salt we expect the sodium and chloride ions at the surface of the dissolving salt crystal, to very rapidly move into solution in the surrounding water. But if the water is stationary, not stirred, then near the surface of the salt crystal, we quickly reach the point where the water is saturated with salt, and no more can dissolve, until the sodium and chloride ions move away.
There is a pretty big push at the University of Surrey to record lectures, so students can view them at another time. I think recording lectures is popular among many students, and I plan to do it for one of my courses next year. But another question is: Does it help students learn more? A recent study by Edwards and Clinton suggests that it does not.
The Department of Education and the Institute for Fiscal Studies have a report out on graduate earnings. The plot for average graduate earnings for women, 5 years after graduation is above (it is Figure 9 of the report, the plot for men is similar). Graduate earnings vary widely by course and by institution — the two are strongly correlated of course, the degrees the London School of Economics (LSE) offers are very different from those offered by the Royal College of Music (shown as ‘RC Music’ above).
Rheology is essentially the study of how things flow, and in practice it is mainly the study of things that have complex flow behaviour, things that are between solid and liquids. A classic example is toothpaste. In the tube it is more or less a solid, but a firm squeeze turns it into a liquid that flows out onto your toothbrush.
I am at a conference in Sorrento, Italy. My hotel room is described as having a ‘hill view’, and as you can see from this picture taken from my hotel room, the description is accurate. That is a genuine Italian hill. In Sorrento, I will be talking about my work on paint drying, but I have a bit of time before the conference sessions start. So, I am also working on a course I am teaching next month for the EU network on RAtionalising Membrane Protein crystallisation (RAMP).
Few things are more boring and take less thought than putting a load of washing in the washing machine, but there is a lot of physics and chemistry going on inside washing machines. The basic idea is remove stains and dirt particles from your clothes, and to then carry them away down the drain. To do this washing powders and pods contain surfactants (soaps) to help detach stains and dirt from clothes, but then these molecules and particles must be removed from the clothes, and washed away.
We all know that oil and water do not mix. But they are not alone, oil, water and mercury also don’t mix, and so water, oil and mercury form three separate liquids, one on top of the other. And if you are really determined you can find not three but six different liquids, none of which mix with any of the others. This is what Ecklemann and Luning did*, to produce the test-tube shown to the lefy, containing six layers, each of a different liquid.
The top layer is a type of oil (petroleum ether), the next is alcohol’s slightly smaller cousin, methanol. Below those are a silicone oil, and then water (with potassium carbonate added so it won’t mix with methanol). Finally, at the bottom is a fluorinated molecule, and then mercury. The mercury is obvious as it is the only metal, the water, methanol and oil are dyed blue, yellow and red, respectively, so we can tell them apart.
I spent part of this week at the kick-off meeting for an EU-funded PhD training network: Engineered Calcium-Silicate-Hydrates for Applications (ERICA for short). The network is run from Surrey and I was invited along to give a talk, and to help out. These calcium-silicate-hydrates are better known as cement. Cement is, very roughly speaking, a type of artificial stone in the sense that when poured it crystallises to form a semi-crystalline solid. The world’s most widely used construction material, concrete, is basically cement plus gravel filler. Concrete is not the most glamorous, but it is strong and above all it is cheap, less than £100 for a ton.