issue contents

Journal logoJOURNAL OF
ISSN: 1600-5767

August 1997 issue

Highlighted illustration

Cover illustration: A crystal of the protein phosphorylase b flash-cooled to 100 K in a 1 mm-diameter mohair loop prior to collection of X-ray diffraction data. Courtesy of Elspeth Garman and Stephen Lee, University of Oxford.

research papers

J. Appl. Cryst. (1997). 30, 421-426
doi: 10.1107/S0021889896014628
link to html
Routines employed in the SORTAV program for identifying and downweighting mismeasured outliers in merging multiply measured data sets are described.

J. Appl. Cryst. (1997). 30, 427-430
doi: 10.1107/S0021889896015464
link to html
This study presents a new technique for calculating the mean crystallite size and root-mean-square strain combining the variance method and the fit of the diffraction profiles by a pseudo-Voigt function.

J. Appl. Cryst. (1997). 30, 431-442
doi: 10.1107/S0021889896015749
link to html
Basic principles of a global evaluation technique for small-angle scattering data of interacting particles are presented.

J. Appl. Cryst. (1997). 30, 443-448
doi: 10.1107/S0021889897000186
link to html
A method to obtain the orientation distribution function of a polycrystalline material diractly from X-ray diffraction spectra is presented. It uses the maximum-texture-entropy assumption to reduce the diffraction data needed for the quantitative texture analysis.

J. Appl. Cryst. (1997). 30, 449-455
doi: 10.1107/S0021889897000174
link to html
Analytic calculation and Monte Carlo simulation of peak-shift effects due to the partial burial of the diffracting gage volume are successful in showing the origins of anomalous peak shifts in neutron strain measurements. The Monte Carlo simulation fits experimental measurements of such shifts in a nickel powder sample.

J. Appl. Cryst. (1997). 30, 456-460
doi: 10.1107/S0021889897000721
link to html
A new Laue technique, recommended for the real-time observation of structural changes of crystals in an environment of heat or an electric or magnetic field, is presented.

J. Appl. Cryst. (1997). 30, 461-466
doi: 10.1107/S0021889897000861
link to html
The equation of state of quartz has been determined with high precision to a maximum pressure of 8.9 GPa by high-pressure single-crystal diffraction. The new equation of state can be used to determine pressure to a precision of 0.009 GPa at 9 GPa.

J. Appl. Cryst. (1997). 30, 467-475
doi: 10.1107/S0021889897001672
link to html
A method for quantifying two forms of α-cristobalite in devitrified alumino-silicate fibres is given. The different natures of these two forms of α-cristobalite were examined by X-ray diffraction and differential scanning calorimetry.

J. Appl. Cryst. (1997). 30, 476-486
doi: 10.1107/S0021889897000745
link to html
A method is described to diffuse rare gases into protein crystals at elevated pressure and to shock-freeze these crystals without loss of the protein-associated rare gas.

J. Appl. Cryst. (1997). 30, 487-494
doi: 10.1107/S0021889897001696
link to html
Glasses containing Ag(Cl, Br) or Ag needlelike particles are studied by fitting of a two-dimensional model to small-angle X-ray scattering data obtained at the HASYLAB (DESY) synchrotron source.

J. Appl. Cryst. (1997). 30, 495-501
doi: 10.1107/S002188989700201X
link to html
The calorimetrically and dielectrically observed phase transi- tions close to 675 K in Ba6CoNb9O30 and 590 K in Ba6FeNb9- O30, together with the dielectric hysteresis that each exhibits, verify the structural prediction that the materials are new ferroelectrics.

J. Appl. Cryst. (1997). 30, 502-506
doi: 10.1107/S0021889897001945
link to html
The work describes a novel application of a recently developed statistical partial least-squares regression technique for the problem of establishing relationships between experimental variables in crystallization trials and the experimental results.

short communications

J. Appl. Cryst. (1997). 30, 507-509
doi: 10.1107/S0021889896012745
link to html
Application of local temperature control to ΔT-grown single crystals allows tailoring of the size.

J. Appl. Cryst. (1997). 30, 510-511
doi: 10.1107/S0021889896012812
link to html
New expressions for the diffraction elastic constants are presented for a cubic polycrystal that is statistically homogeneous, isotropic, and disordered.

laboratory notes

J. Appl. Cryst. (1997). 30, 512
doi: 10.1107/S0021889896013544
link to html
A model of an air cooler in a laboratory chamber furnace, for simultaneous regulation of different crystallization rates in a series of test tubes with the purpose of obtaining crystals, is presented.

J. Appl. Cryst. (1997). 30, 513
doi: 10.1107/S0021889896015865
link to html
This work describes a micrometric manipulating device for easy mounting of small crystals on a needle along a preferred orientation.

fast communications

J. Appl. Cryst. (1997). 30, 514-516
doi: 10.1107/S0021889897004214
link to html
A method is proposed to estimate and correct for the amount of λ/2 contamination inherent in area-detector data. The method has been tested on data obtained with a charge-coupled-device detector using Mo Kα radiation. For routine data sets, the correction is shown to be insignificant.

J. Appl. Cryst. (1997). 30, 517-525
doi: 10.1107/S0021889897005918
link to html
A generalized spherical harmonic description of the texture for polycrystalline materials has been implemented in a multiple phase/multiple data set Rietveld refinement code and is demonstrated with an example.


J. Appl. Cryst. (1997). 30, 526
doi: 10.1107/S002188989709897X

new commercial products

J. Appl. Cryst. (1997). 30, 526
doi: 10.1107/S0021889897098968
Follow J. Appl. Cryst.
Sign up for e-alerts
Follow J. Appl. Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds