Today is a holiday, short note on data corrections

Dear readers,

Unfortunately, this week I do not have anything ready for you. It is with great regret that I must therefore skip this week, and break my “once-a-week” posting schedule. Regular scheduling should return next week.

Just a quick note, however. Thanks to Sylvain Prévost bringing this back to my attention; Brûlet et al. derived a very similar equation to what was derived in last week’s post. Additionally, Strunz et al. [2] have some additional considerations for transmission factors that may need to be considered in X-ray scattering as well (in particular for ultra-small angle X-ray scattering).

Hopefully I will have the time to look into these things in the near future and give you some more insight on the magnitude of these problems. As suggested by Sylvain, it may be a good idea to adapt the “imp2″ data reduction software to be able to handle a more general consideration of transmission factors (then supporting both SAXS and SANS). A bit of thought is needed on how to enable fancy background subtraction while keeping the modular, flexible nature of the program.

[1]: Annie Brûlet, Didier Lairez, Alain Lapp and Jean-Pierre Cotton, “Improvement of data treatment in small-angle neutron scattering”, J. Appl. Cryst. 40 (2007), 165–177. [journal link], [free link]

[2]: P. Strunz, J. Scoversheet.dviaroun, U. Keiderling, A. Wiedenmann and R. Przenioslo, “General formula for determination of cross-section from measured SANS intensities”, J. Appl. Cryst. 33 (2000) 829–833. [journal link]

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Lessons from history: a look at GE’s early outreach videos

A portrait of Dr. Coolidge seen in the movie "Exploring with X-Rays, Part 1" from GE.

[ed: I'm giving a general SAXS talk at BESSY, the Berlin synchrotron on Friday the 11th at 10:00 local time. Contact me or Andreas Thünemann at BAM for more information]

Whenever I think of General Electric, I imagine a stereotypical American company: a top-heavy organization, forcing its employees to learn and recite GE’s mission statement, run by armies of beancounters and administrators who are trying their best to increase value for the shareholders while running everything else into the ground. This, of course, in stark contrast to the academic world typified by: a top-heavy organization, encouraging its undervalued employees to slave away for the dream of doing something of worth in the little time they have left besides doing administrative tasks, while the army of beancounters and administrators are trying their best to satisfy the research assessment committees and running everything else into the ground. Anyway, I digress…

GE has released some films from their early days of bright bulbs working in their research laboratories, some of which are very relevant to X-ray sciences. These videos are very interesting for a variety of reasons… Read more »

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Nature Chemistry publishing on Martin’s Magical Molecules

Martin working hard at NIMS.

The long wait is over! A new publication is out, this one written by Martin Hollamby over the course of three tough years. For those who haven’t seen his one-minute intro video, Martin is investigating the behaviour of molecules in solvents. In his excellent paper, he shows how his range of molecules can self-assemble in (hydrophobic) solvents to form a variety of shapes and forms.  Read more »

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Guest post by Dr. Jan Ilavsky: Meet an Ultra-scatterer!

Ilavsky at the beamline II

[ED: I've started asking around for guest contributions for the LookingAtNothing site, in order to provide a broader view of the SAS-related activities than I could ever hope to achieve by myself. Our second guest to talk about his work is Dr. Jan Ilavsky of the Argonne National Laboratory.]

Maybe you heard my name, Jan Ilavsky, perhaps in association with Ultra-Small Angle Scattering (USAXS) instrument, Irena or Nika software packages, or in relationship with Glassy Carbon absolute intensity standard? We will get to each of these in a few lines, but in order to understand me, you need to understand my history. Read more »

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