Also refer to the Fakultät für Physik - Universität Tübingen, Institut für Kristallographie on "Automated Guinier Diffractometer" and software such as Simref, Simpro and Maximum-Entropy Programm MEED, MEEDCAB und MEND
From: Ariel Gomez Gonzalez ariel@lae.ff.oc.uh.cu Date: Tue, 27 Apr 1999 07:27:01 -0400 (CDT) To: RIETVELD_L Distribution List rietveld_l@ill.fr Subject: digital data from guinier camera film Precedence: list Reply-To: RIETVELD_L Distribution List rietveld_l@ill.fr Hi everybody, We have a Guinier camera from which we would like to get digital data, can anybody help us ? Any information will be appreciated, suggestion about companies that supplies optical densitometers or home made alternatives will also be wellcome. Thanks in advance, Ariel ________________________________________________________ Ariel Gomez Gonzalez Laboratorio de Analisis Estructural, Departamento de Ciencia de Materiales, IMRE, Universidad de la Habana, La Habana 10400, Cuba
From: rhayashi@bert.chem.wisc.edu (randy hayashi) Newsgroups: sci.techniques.xtallography Subject: Re: special characters for crystallography Date: 23 Apr 1997 19:23:09 GMT Organization: u wisconsin In article <335E334C.B1A@cryst.unige.ch>, CERNY Radovanwrote: > Does somebody know how to write a bar over a character in Word (for > example P-1)? Use overstrike mode. Put commonly used stuff like -1 into your glossary. I suppose I can send you my word glossary file, but I don't have it here at
From satr@esc.cam.ac.uk Date: Tue, 27 Apr 1999 17:23:46 +0100 To: RIETVELD_L Distribution ListSubject: Re: digital data from guinier camera film Precedence: list Reply-To: RIETVELD_L Distribution List At 07:27 27/04/99 -0400, you wrote: >We have a Guinier camera from which we would like to get digital data, can >anybody help us ? >Any information will be appreciated, suggestion about companies that >supplies optical densitometers or home made alternatives will also be >wellcome. We use Guinier cameras a lot and employ an Agfa desktop scanner with a transparency adaptor linked to a PC. We bought this some years ago. I imagine these are pretty cheap these days (you can get scaners as good for well under $100 now). NIH image provides a useful (and free) method for converting the image into an intensity vs. 2-theta file. Take a look at the paper: "Digital analysis of X-ray films" by D.C.Palmer, MINERALOGICAL MAGAZINE, 1997, Vol.61, No.3, pp.453-461 Abstract: High-resolution intensity profiles can be generated from X-ray diffraction films using a desk-top scanner and computer image analysis. The resulting intensity profiles have spatial resolutions equal to, or exceeding that of modern powder diffractometers - at a fraction of the cost. This technique provides an economical way of preserving the information stored in libraries of old (and deteriorating) powder diffraction films. The same technique can also be extended to permit quantitative analysis of single-crystal diffraction films. Simon Redfern Dept Earth Sciences University of Cambridge Downing Street Cambridge CB2 3EQ UK
To: ariel@lae.ff.oc.uh.cu, rietveld_l@ill.fr Subject: Digital Data from Film Cc: amdattel@pams.ncsu.edu, dssmith4@pams.ncsu.edu, hi356ko@unidui.uni-duisburg.de, smsulliv@pams.ncsu.edu Precedence: list Reply-To: RIETVELD_L Distribution ListAriel We use a Guinier camera which gives film strips linear in units of two theta. Our samples are run with silicon as an internal standard. The film is scanned in to a TIF file using a standard scanner with 600 DPI resolution. A profile of intensity vs units of length is extracted using NIH Image (http://rsb.info.nih.gov/nih-image) and exported as an ascii XY file. To convert the arbitrary length scale into units of two theta I used "Winfit" (http://www.geol.uni-erlangen.de)to peak pick the Si lines and a program provided by Dr. Koeckerling (hi356ko@unidui.uni-duisburg.de) to get values needed to convert the arbitrary length units to two theta values. The actual conversion was done in an XCEL spreadsheet which can also render reasonable graphics. The program "convert" (http://www.ceramics.irl.cri.nz/Convert.htm) took the XY file format into GSAS format for Rietveld refinement. Our goal is to use this relatively inexpensive, easily accessible camera to explore unknown phases and design in-situ time resolved powder x-ray diffraction experiments which we carry out with Jon Hanson at NSLS X7b using a translating image plate camera developed by Poul Norby and co-workers. The Rietveld list-serv has been invaluable to me over the last several months of my graduate school career and I thank all the contributers. In conjunction with my last post I wish to thank Lachlan Cranswick for making me aware of multiple versions of "convert", as well as Nita Dragoe and Mark Bowden for providing versions of this program for a Windows environment. Patrik Dahlke has kindly provided an alternative program for conversion of XY data to GSAS format. Stefan Krumm's "WinFit" is very nice and I wish to thank him for its development and distribution. Roger Roger M. Sullivan Department of Chemistry North Carolina State University smsulliv@pams.ncsu.edu
Henry Barwood Powder Film Digitisation Tutorial
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