## Tag Archives: Review

## The value of years: good stories and advice from M. H. J. Koch

One paper I managed to miss for my review paper on data corrections is a paper by M. H. J. Koch from Hamburg. The paper is written in a nice informal way, replete with good quotes, where he talks about his experiences in instrument development for SAXS and WAXS beamlines. In particular the paper details […]

## A review of data collection and correction procedures.

Following my previous work in progress detailing the data correction steps to obtain good data, I finally had the chance to write this down in a review article. This review article (open access) has been submitted on Monday. After it has been reviewed and (hopefully) published in the journal, I will ensure that that latest version is […]

## Comments on Deschamps, 2011 and A clarification on Guinier for Polydisperse systems

After browsing through a recent Journal of Applied Crystallography, I came across a paper by Deschamps. It indicates to me that there is a slight lack of information communication in some aspects of SAXS. Firstly, it mentions in the introduction that the advanced (Fourier-transform-based) SAXS analysis methods cannot “extract simultaneously the precipitate form factor and […]

## Notes on Guinier

…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, […]

## Read Ruland and more free reading (textbooks!)

Catching up to current affairs, I stumbled across this beauty. Now, I find this paper starts a little bit chaotic, but very quickly we come across some very useful equations indeed, and a link between the used equation for their analysis of phase transitions in fluids, and various other equations such as the Ornstein-Zernike structure […]

## Bayesian Inverse Fourier Transforms

Although I cannot say I completely grasp the underlying theory, the Bayesian approach to the Inverse Fourier Transformation of (isotropic) small-angle scattering patterns certainly appeals to me. The idea is that the small-angle scattering pattern can be transformed (back) into real-space, resulting in either a distance distribution function p(r), a correlation function gamma(r) (=r^2 p(r) […]

## Particle size distribution: review of “Small-Angle X-ray and Neutron Scattering of Polydisperse Systems: Determination of the Scattering-Particle-Size Distribution”

The determination of the particle size distribution from small-angle scattering curves is usually achieved by assuming a certain statistical size distribution model (f.ex. a Schultz distribution, a Gaussian distribution or a log-normal distribution), and fitting this to the data using a non-linear least-squares optimisation method. Fitting multimodal distributions then implies the addition of multiple contributions, […]

## SASFIT software

The famous question of the uninitiated in small-angle scattering is: “Do you have a bit of software which will give me an answer from my data?”. After a lengthy explanation (coloured with some anecdotes) about why small-angle scattering is not a uniquely defined problem with an often unique answer such as wide-angle diffraction might be, the […]