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1999 Annual Report of the IUCr Commission on Small-Angle Scattering

  • Subject: 1999 Annual Report of the IUCr Commission on Small-Angle Scattering
  • From: "John D. Barnes" <john.barnes@nist.gov>
  • Date: Sat, 5 Jun 1999 05:28:12 -0400
1999 Annual Report of the IUCr Commission on Small-Angle Scattering

During the past year the IUCr Commission on Small-Angle Scattering has 
continued in its tutorial and community building efforts with three 
workshops. An interlaboratory test program to evaluate small-angle 
scattering test methods is currently in its initial design stages. The 
Commission is providing considerable assistance to the SAS 99, the XI 
Triennial World SAS Congress, taking place in Brookhaven National Lab, 
USA, on 16-20 May 19999.

The first workshop, on "Data Handling for Small-Angle Scattering," was 
held in conjunction with the 1998 American Crystallographic Assn Annual 
Meeting in Arlington, VA. Commission members John Barnes and Dmitri 
Svergun were aided by Malcolm Capel and Jan Skov Pedersen as they 
explored issues ranging from proposed standard data formats to 
visualization tools for user facilities.

Another edition of this workshop will be conducted on 16 May 1999 in 
conjunction with SAS 99. The workshop title is canSAS II in recognition 
of the close relationship between the Commission and the canSAS 
(Collective Aid to Nomadic Small-Angle Scatterers) project (see 

A second workshop, conducted as a tutorial for end users of SAS 
techniques in the polymer field, was held under the joint sponsorship of 
the Commission and the American Chemical Society Polymeric Materials 
Science and Engineering Division. The workshop was part of the ACS's 
August 1998 National meeting in Boston, MA. The workshop title was "SAS 
in the Industrial Plastics Laboratory." Commission chair Dr. John Barnes 
was the instructor.

Technical activity in the standardization area is slowly ramping up. Dr. 
Dmitri Svergun and Marc Malfois of EMBL have circulated drafts of a 
sasCIF format and have worked with Drs. Brown and Toby of COMCIFS to 
bring sasCIF into conformance with the applicable standards. This work 
will be carried forward at canSAS II and it is expected that the sasCIF 
format will be used in the upcoming interlaboratory test programs.

At the time of this writing a variety of compression-molded samples of 
various polyethylene resins are being evaluated as candidate samples for 
an interlaboratory test program. The next stage of the project involves 
distributing these samples to a limited number of trusted laboratories. 
These labs will be asked to evaluate the samples using their standard 
procedures with the goal of providing the best possible description of 
the SAS properties of the samples. They will be asked to report the 
results using the sasCIF standard. 

A task group will review the results from this preliminary study and then 
design a suitable protocol for a larger study involving any labs in the 
SAS community who want to participate. Those members of the community who 
are aware of the project have been quite supportive. The intent and the 
approach are somewhat different from that of the 1978[1] effort, but we 
hope that it will prove to be equally useful.

[1] Hendricks, R. W. et al, J. Appl Cryst, 1978, vol 11, pp 196-205.

Respectfully submitted

Dr. John D. Barnes               email: john.barnes@nist.gov
Natl Inst of Stds and Tech       Voice: 301-975-6786
100 Bureau Drive, Stop 8544        FAX: 301-975-4977
Gaithersburg, MD 20899             URL: http://www.nist.gov/sas
  or http://polymers.msel.nist.gov/staff/detail.cfm?SID=110