Travel part 1: York and Leeds

2014/05/15 // 1 Comment

York and Leeds, the first 40% of the presentations all done. Still to go: Lille, Birmingham and Nottingham, and a few synchrotron days in between. Read on for the experiences at the first two places:


Back from holiday and SAS2012

2012/12/08 // 0 Comments

SAS2012 turned out to be quite amazing, and I had a blast! After the conference some weeks were spent on holiday and therefore this site did not get updated. There should be new stuff coming up in a week. Cheers!


Lessons in outreach to be learned from Japan’s disasters

2011/03/21 // 3 Comments

(warning: this rather lengthy piece may contain personal opinions and has little to do with small-angle scattering. There is a nice bit about graphics, though.)   In the wake of the global public panic following the reporting around the nuclear reactor struggles (as opposed to the expected >15 kilopeople deaths in Myagi prefecture due to the tsunami alone), perhaps it is time for us to consider what we can learn from the way the media and the educated dealt with these developments. For us, it can be used to gain insight into how to communicate with journalists, and we can come up with ideas about what we (the (educated) public) could do better in this situation. In summary, the following events happened in rapid succession: After the initial strike of an earthquake with its epicenter off the coast of north-east Japan, a tsunami struck the coast of north-east Japan (but fortunately not entering Tokyo Bay), wiping out some villages along the coastline and causing the large majority of the casualties of the event. Trains went missing and an airport was flooded (mind you, they have an enormous density of airports in Japan so this was not too surprising). Efforts are currently ongoing to retrieve the people marooned, and to reestablish supply-lines of food, water and electricity. Focusing on the reactors, during the earthquake all reactors in affected areas started emergency shutdown procedures, stopping the main fission reaction right away and started cooling down of the reactors. Given that the reactors are of the second generation type, active cooling is required (new generation 3 reactors do not need circulation pumps but can cool by convection instead). Several power plants shut down properly after this event (albeit with some minor issues in some). However, at the Fukushima Daiichi plant (consisting of 6 reactors, three of which were already shut down at the time of the quake), the tsunami which arrived minutes later wiped out the power generators and the external power supply lines. This left only the batteries intact. With the batteries, 8 hours of cooling was achieved, which was not sufficient time to reestablish electrical supply. After failure of the battery power, the reactor temperatures of the previously active reactors started increasing due to residual activity in the fuel rods. At a much slower pace, the temperatures in the fuel storage pools also increased. After some time, efforts started to cool down the reactors and to release the formed steam (as the pressures in the reactors increased upon steam formation). Hydrogen formed by oxidation of the zirconium fuel-rod cladding with steam was released as well, causing explosions in some reactor buildings. After several days of hard work by the plant engineers, the situation is stabilizing with the arrival of power and cooling water from fire engines. A good summary per reactor is provided on a daily basis by the Kyodo news agency (f. ex. Sunday evening, 20th of March). Due to the release of steam and the cooling efforts, some radioactivity in the form of light isotopes (as of iodine and cesium) was released into the surroundings and found in f.ex. foodstuffs. For more detail, check out the Wikipedia page. The foreign media action during this entire situation was abominable. The Japanese agencies mostly provided “matter-of-fact” updates and regurgitations of press releases from the government and the power organizations (which may also not be perfect, as they have been accused of putting a too positive spin on the news as well). Good sources of Japanese news for English readers are Kyodo, NHK, and to a lesser degree, Asahi Shimbun (updating quite infrequently with old information). Many foreign news sites reported bad and/or sensationalist excerpts instead, fanning the flames of fear and causing people half a globe away to start buying potassium iodine pills and closing down power plants. A compilation of erroneous post-quake reporting can be found here. Opinion pieces on the media behaviour can also be found here, here, here and here, and more generally about their response to the earthquake and tsunami here. Now, sensibility is returning to some of the stories run by the media. This may be due to the limited public attention span, lack of exciting news and sensational quotes, the skew of news reporting skewing in another direction, or the journalists becoming more well-read on the topic, but I think it may also have to do with the emerging availability of good graphics. There have now been several good graphs to show how the different levels of radiation stack up, f.ex. those here and here. The NY Times also has a good graph showing the progression of detected radiation over time. The BBC has a limited graphical explanation of the course of events. Cooling down of the spent fuel storage pools is shown here, albeit with a superfluous dimension thrown in for no good reason. However, graphs have also been used to instill fear, such as the ones here, here and here (although I cannot understand the graphs in this last one). With these graphs, some perspective can be attained about the scope of the events, but one must be wary of sensationalist graphics popping up as well. So what can be learned from this? Well, one message is that in such an event, generating graphics about the situation has to be one of the top priorities to all who can. Besides these, voicing a moderate opinion in the face of the extremists has to be considered, as the voice of reason is rarely heard. Now most of us do not have a degree in nuclear physics, reactor design or suchlike, but we can nevertheless offer an educated view to the situation, if we take the time to read the reports and distill the facts from them. While this is risky (Carl Sagan is mildly criticized for speaking outside of his expertise by Ben Goldacre, when he warned of nuclear winters, for example), it is also one of the only ways of educating the general public about science in general. […]


Live FT video

2011/02/04 // 1 Comment

A demonstration of the live Fourier Transform showing scattering patterns can be seen here:


Live Fourier transform

2011/02/03 // 8 Comments

During some recent presentations, I have used a small matlab program giving me a live Fourier transform of the laptop camera input. It can be used in combination with some printed “structures” to show what we would see on a SAXS or WAXS detector. The idea is not mine, I heard that it was used by dr. Henrik Lemke for his Ph.D. defense to show the effects of lattice strain on the diffraction pattern. It turns out to be quite popular with the audience so far, so I will post the code for Matlab running on a macbook Pro here. Feel fee to use the code. I will also make a short movie showing one example of how to use it. I am sure you can think of many other useful purposes for it! The package is here: FT_cam_package Since it is so specific in its application, there is no documentation. Also, run “FTcamdemo” and the rest should be quite self-explanatory in the GUI that comes up. This package uses (and comes with) camera image capture code (Java) by Kalle Kempe and Ikkjin Ahn.


Notes on Guinier

2011/01/02 // 2 Comments

…well, his famous SAXS analysis method. This documentGuinier_short, copyright Brian Pauw gives a short description and review of the applicability of the Guinier method to polydisperse systems. It also shows, through analysis of simulated data, what q-range should be measured for the Guinier method to be valid. In short, the rule of qmax=1.3/Rg still holds, but Rg in polydisperse systems is the volume-squared weighted Rg of the distribution. This then implies that the Guinier method for polydisperse systems quickly becomes unusable as the required qmax cannot be reached with anything but USAXS systems for polydisperse samples. This text (the linked PDF) is released under copyright (copyright by Brian R. Pauw, 2011) as I may want to include some of this in a later publication. I hope you understand…


More Youtube videos

2010/10/31 // 0 Comments

So, I could not do what I promised last time, the Monte-Carlo fitting works on perfect simulated scattering patterns but is as of yet unable to deal with the addition of a flat background. So I will have to take a raincheck. In the mean time, I have made two videos (part 1 and part 2) together with some colleagues during my time in Denmark. The video demonstrates small-angle scattering using laser light scattering on a hair. In part 2, the diameter of the hair is calculated. (I watched too many Carl Sagan videos and I am impressed and encouraged by them…) Check out the videos: Part one: Part two:


Teaching and how it applies to us.

2010/08/22 // 0 Comments

We teach. Every one of us. If we have a classroom of students, it is obvious, but also when we talk to colleagues, we sometimes try to teach them something (even if it is only our point of view). I spoke last time about the teaching horrors that modern textbooks have. Well, this video by Dan Meyer explains why the textbooks are absolutely not helping to teach by asking the questions wrong, and he proposes an alternative way to pose the questions. He also, by the way, has a nice blog full of examples of how to get a class of students to actually think. This gets me thinking. How can we apply this to our presentations? Are we really engaging our audience by starting with a “talk outline”, or should we pose the final question as simple as possible and work from there? I will be experimenting with this and I will let you know how it goes!

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