Competing Ferri- and Antiferromagnetic Phases in Geometrically Frustrated LuFe2O4

We present a detailed study of magnetism in LuFe2O4, combining magnetization measurements with neutron and soft x-ray diffraction. The magnetic phase diagram in the vicinity of T_N involves a metamagnetic transition separating an antiferro- and a ferrimagnetic phase. For both phases the spin structure is refined by neutron diffraction. Observed diffuse magnetic scattering far above T_N is explained in terms of near degeneracy of the magnetic phases.Comment: 5 pages, 5 figures + 6 pages of supplementary informatio

The vertical drift chamber as a two dimensional focal plane detector for light and heavy ions in the QMG/2 spectrometer

A multiwire drift chamber of the VDC-type which is used as a focal plane detector for the QMG/2 spectrometer of the KVI is discussed. With this detector both the coordinate in the dispersive direction (resolution 150 μm fwhm) and the coordinate in the direction perpendicular to the bending plane of the spectrometer (resolution < 1.0 mm fwhm) are measured. The angle in the dispersive plane is measured with a resolution of 0.5° fwhm. This VDC also provides an energy-loss signal and it can be used for both light particles and ions up to about mass 20. An overall energy resolution of has been obtained with beams of various particles and energie

Echocardiographic dimensions and maximal oxygen uptake in oarsmen during training.

We studied nine freshmen and 14 senior oarsmen undergraduates during seven months of training and compared them with 17 age and sex-matched sedentary control subjects in order to assess the influence of heavy physical exercise on cardiac dimensions and maximal oxygen uptake. Standard M-mode echocardiographic techniques were used. At the start of the season senior oarsmen had a greater left ventricular end-diastolic dimension, and a thicker interventricular septum and posterior left ventricular wall than control subjects and freshmen oarsmen. The two latter groups did not differ from each other. During the training period there was a slight and gradual increase in left ventricular end-diastolic dimension, and interventricular septum and posterior wall thickness in freshmen. In seniors only left ventricular end-diastolic dimension increased significantly. Maximal oxygen uptake showed a distinct increase between the fourth and seventh month during the period of intensive rowing training. There was no relation between echocardiographic variables and maximal oxygen uptake. A combination of heavy dynamic and static exercise can thus lead to significant changes in both left ventricular wall thickness and chamber size within months. Echocardiographic variables measured at rest cannot be used as a suitable index of performance capacity