Does it matter part 6.1: The effect of finite width pixels

2015/10/06 // 0 Comments

This short investigation was prompted by the instrument here at BAM and the associated Anton Paar software. The software determines the beam center behind the transparent beamstop, apparently based on a polynomial fit through (just) four datapoints. This means that the beam center can vary a bit from measurement to measurement, typically on the order of fractions of a pixel. We then set out to quantify just how much that, as well as the finite pixel width, would affect our size determination. Here is a back-of-the-envelope calculation…


SAS2015 review

2015/09/22 // 0 Comments

The last week was one of conference goodness, with plenty of breaks lit up by interesting conversations. Here are the pictures and opinions gathered while prowling the floors, in random order…


A moment of calm

2015/09/09 // 0 Comments

After last week’s busy schedule, this week is positively quiet in comparison. The calm is merely temporary, however, as the big SAS conference will kick off this Sunday. During this conference, I hope to meet and greet many of you (and I think I owe a few drinks as well left and right). I have been hard at work preparing the triad of posters for this, which I hope will draw some interest and kick off some interesting conversations (which is, after all, the point of a poster). Speaking of posters, here is one I never showed before. It showcases the applications of McSAS, and has been presented at the CanSAS meeting in Mito earlier this year. The full poster can be downloaded here. See you next week! For those who are not coming, I can always be invited to give a talk :).


Stranger in a strange land

2015/09/05 // 3 Comments

I imagine some of you wondering what happened to last Tuesday’s post, and all I can say is: life is hard without internet in a new country. A lot has happened since our arrival, and a lot more will happen in the near future. Meanwhile, two posters remain to be finished before the SAS conference in a week. So what has been done until now? For an insight into moving foibles, please read on…


Holiday post: art of manliness.

2015/08/26 // 0 Comments

An off-topic post for this week, as we are at the last of the holiday posts. I will just briefly mention that the deadline for registration for SAS2015 is very fast approaching (and I still have three posters to finish…). For those who are looking for styling tips for their appearance at the conference, here is a site full of arcane knowledge on dress codes (amongst other topics, but unfortunately geared towards men): A bit of knowledge can’t hurt!


Holiday… no post v2.0

2015/08/18 // 0 Comments

Weeks pass at an amazing rate while on holiday, and so yet another one has passed. Why not take a wander through the previous posts while you are here? P.S. have you signed up for the 2015 SAS conference in Berlin yet?


Holiday post: image vs. averaged background subtraction

2015/08/11 // 2 Comments

When correcting data for the many possible data artefacts, I usually prefer to do these corrections on the 2D images as opposed to the azimuthally averaged data (often referred to by the misnomer “integration”). This needs to be done for some direction-dependent corrections, such as for the polarization correction, but not necessarily for others. The background correction, for example, can be done in two ways: subtracting the background image (2D) from the measurement image, or subtracting the azimuthally averaged background data (1D) from the azimuthally averaged measured image. To illustrate the difference, perhaps a small demonstration can suffice.


Holiday… no post

2015/08/04 // 0 Comments

My sincerest apologies, but there must be no post for this week. There are a few things brewing, but I hardly understand them myself yet and so must be left to percolate before they can be presented. If only I had prepared posts for the holiday!


Holiday post: Ultra-SAXS version 2 drawing

2015/07/28 // 0 Comments

I am on holiday at the moment, so the blog posts will be a little bit more brief than usual. However, not less exciting! Over the last two weeks, I put together a side view assembly drawing of the latest version of the Ultra-SAXS machine. blue-tinted components are custom metal parts (mostly leftovers from version 1). Reddish parts are 3D-printed components, and white parts are commercial off-the-shelf (COTS) components. The drawing has been made largely by assembling component drawings made by my father for version 1, and technical drawings from the manufacturers of the COTS components. The full drawing, 3D printer files and other documents are available in a Git repository here (CC-BY licensed). It is mostly complete, but there may be a few items still missing.

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