BACKGROUND A questionnaire for patient self-assessment of shoulder function was designed. It was based on the internationally accepted Rowe score. METHOD Explanations and photographs were added to the various parameters to make them easier to understand for the patients. A total of 95 patients completed the assessment form. The validity was tested by a correlation analysis comparing the questionnaire with the original score. RESULTS The questionnaire demonstrated a reproducible and significant (p<0.001), very high correlation (r>0.9) in the overall results and a moderate to very high correlation within single parameters (r>0.68). CONCLUSION Based on these results, it can be concluded that a valid and reproducible assessment of the original score is possible with the new questionnaire. Self-evaluation allows reliable assessment which is not dependent on the examiners or location, resulting in a higher number of patients reachable for follow-up studies.

Due to the lack of long-range periodic order in quasicrystals there are restrictions concerning a straightforward structure analysis on base of X-ray diffraction data. Computed reflection intensities in X-ray diffraction patterns, which are strongly affected by the shape and occupation of hypothetical atomic surfaces, need to be compared with experimental data. The interatomic short-range correlations as to be determined by means of DAFS and XAFS have to be in agreement with these structural models. The use of linearly polarised X-rays allows for orientation sensitive determination of otherwise averaged short-range order information. Additionally wave vector-selectivity of DAFS can yield short-range order information sensitive to sites occupied by atomic species within the coherently scattering structural units.Structural models of decagonal Al-Co-Ni were applied to compute theoretical DAFS and XAFS functions. Calculation of both, energy-dependent structure factors and pair distribution functions obtained within a hypothetical cluster of app. 81 000 atoms as the basis of computation of DAFS are outlined.Co-K and Ni-K DAFS and XAFS measurements at 3 independent reflections of a decagonal Al70Co9.5Ni20.5 single crystal were performed and the experimental data were subjected to quantitative evaluation. The reflections used involved wave vectors parallel and perpendicular to the periodic direction and in a third inclined direction. In agreement with our simulations DAFS of individual reflections and thereby corresponding short-range orders exhibited no differences within the error limits. The same was found for the case of polarized Co-K and Ni-K XAFS results.

We report on long-term observations obtained from powder X-ray diffraction (XRD) measurements with milled Al–Co–Ni of decagonal structure at room temperature under ambient conditions. Several powder samples were prepared from different pieces of initially bulk polycrystalline Al70.7Co13.3Ni16.0 by ball milling for a total period of 14min. The as-milled samples were investigated without any intermediate annealing. While a number of them exhibited X-ray powder patterns without sharp reflections, the specimen in the focus of this report exhibited X-ray reflections, which could be unambiguously attributed to the decagonal structure. Evaluating the time-dependent course of integral intensity and position of the four strongest reflections we found evidence that, due to milling, order along the periodic direction is disturbed more than order within the quasiperiodic planes. In a first stage of room temperature ageing, order is restored within the first ∼100h. In a second stage, quasiperiodic order recovers within the planes, which is probably caused by the relaxation of phason strains induced by the milling procedure. Fourier analysis of the XRD patterns yielded differences in the radial distribution function (RDF) at about 6Å and less pronounced at 3Å, indicating the preferred occupation of bond lengths between transition metal (TM = Co, Ni) atoms rather than pairs involving Al.

Powder samples of Al70.7Co13.3Ni16.0 were investigated by X-ray diffraction in the temperature range 15–300 K. At T=150 K at least three additional reflections were observed. The onset temperature and hysteresis-like behaviour was monitored more closely. The reflections cannot be indexed using integers of reflections of the known decagonal lattice. Moreover, near this temperature lattice parameters of the decagonal phase showed deviations from a smooth curve. We suggest the occurrence of an intermediate phase, which, however, seems to be a property of the powdered sample, i.e. caused by milling single crystals. We will solely describe the experimental facts as they are and make a suggestion for the transition mechanism. It is assumed that the new reflections are due to a periodic superorder of the decagonal lattice as described for a Ni-rich alloy in the literature. From the distance of those satellite reflections to main (Bragg) reflections in reciprocal space we estimate the modulation length of the quasicrystalline substructure to be 10a, i.e. ∼38 Å.

Abstract The temperature dependence of lattice parameters a in the quasiperiodic plane and c in the periodic direction of decagonal Al70.7Co13.3Ni16.0 was probed using X-ray powder diffraction in the temperature range 15–300 K. Both parameters were fitted by means of positions of 22 Bragg reflections for each temperature. Temperature dependences were modelled best by second order polynomials leading to linear thermal coefficients α(T) = 8.1(33) · 10–7K–1 + 3.9(2)· 10–8K–2T in the quasiperiodic plane and γ(T) = 1.7(6) · 10–6K–1 + 3.8(3) · 10–8K–2T in the periodic direction, respectively. Thus we found the anisotropy ratio γ(T)/α(T) to decrease with increasing temperature from 1.10 (at 15 K) to 1.19 (at 300 K). Besides pecularities around 150 K indicating an intermediate phase formed by superordering, we observed deviations from the general smooth course between 15K and 50K for both lattice parameters.

The lattice parameter a of face-centred icosahedral Al70.3Pd21.7Mn8.0 was determined using X-ray pow der diffraction in the temperature range between 15 K and 300 K. Fitting its temperature dependence by a polynomial of second order a linear thermal expansion coefficient alpha(T)= 1.19(15).10(-6) K-1 + 4.40(21).10(-8) K-2 T has been derived. After long-period low temperature ageing the appearance of an additional reflection at /k/ = 1.716 Angstrom(-1) was observed.

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The local structure of two multilayer systems Co/Zr of different layer thickness during annealing well below the crystallisation temperature was determined by means of extended X-ray absorption fine structure (EXAFS), performed at Co K edge as well as at Zr K edge. By taking additionally wide angle X-ray scattering (WAXS) measurements into consideration, the averaged EXAFS signal summing up contributions of all exited atoms in the sample could be separated into parts belonging to the crystalline and amorphous phases which occurred in the intermediate states of the system Co/Zr simultaneously. The existence and conservation of fibre textures within the crystalline layers and the conservation of periodicity in chemical composition perpendicular to the layer plane could be proved. Moreover, intensities of the 0002 and 10–11 reflections of Zr provided reasonable starting models for fitting crystalline Zr to a subshell model of close lying shells. Coordination numbers obtained for the crystalline phases of Co and Zr agreed well with the bulk data. Looking from the position of either absorbing species the atomic radial distribution was evaluated. Zr neighbours dominated for Zr as well as for Co central atoms. Around Co atoms we found Co at typical distances of 2.45, 2.78 and 3.06 Å; around Zr the Zr neighbours occupied neighbour shells at 3.07 and 3.30 Å. Distances between unlike atoms were found to be 2.65 and 2.81Å. These values describe single symmetric contributions of asymmetric pair distributions derived on the basis of multiple Gauss analysis. From EXAFS and WAXS we concluded that the amorphous part of the layer system is initially dominated by a Zr-rich phase which competes with a second amorphous phase of an approximate composition Co50Zr50 during the the subsequent stages. As the reaction proceeds the latter grows while the Zr-rich phase is reduced.

The defect spectrum in plastically deformed GaAs is investigated by positron lifetime measurements and transmission electron microscopy. Different types of defects such as shallow positron traps, impurity-vacancy complexes, vacancy clusters, and dislocation-related defects are identified. The nature of these defects is analyzed and the relation between dislocation movement and relaxation to point defects is studied.

Our recent work aimed to the investigation of structural stability of decagonal Al-Co-Ni single crystals. We focused our interest on samples with compositions at the edge of the narrow existence region of the decagonal phase, which may tend to exhibit structural instabilities. Herein, we report on Diffraction Anomalous Fine Structure (DAFS) measurements on an extended, polished single crystal of composition Al70Co9.5Ni20.5, which was cut perpendicular to the periodic (00001) direction. Results of these measurements gave rise to apply grazing incidence X-ray Absorption Fine Structure (XAFS) to probe the short-range order (SRO) of the uppermost part (~ 50 µm) depth-resolved. DAFS (at K absorption edges of Co and Ni) and XAFS (Co K-edge) experiments were performed at beamline CEMO using Si 111 and 220 double crystal monochromators, respectively. As the DAFS data was subject to the attenuation correction formalism including secondary extinction effects for ideally perfect crystals (see (1)), it became evident, that the major criterion of a successful attenuation correction could not be fulfilled. That is a monotonic overall course of the corrected data below and above the absorption edge as demonstrated by Meyer et al. (2). The formalism applied considers attenuation and scattering on the entire path into and out of the sample up to a depth, t, as given by (3). In the present case we successfully modified the correction by considering pure attenuation in a surface layer of thickness, d, exclusively. This implies that this layer does not contribute to the diffracted signal of the reflection under investigation. Hence we concluded that the atomic structure of this layer differs from the bulk. Fig. 1 displays the corrected DAFS data following the latter approach for different values of d, among which there is a optimal value producing a monotonic course. The thickness derived from the Co and Ni DAFS was typically in the order of 1µm.