Synthetic HRTEM images are simulated using Jems® simulation software with a model specimen consisting of a film of strained silicon on top of a relaxed Si0.82Ge0.18 alloy substrate in the [110] zone axis, where biaxial tensile strain exists in the strained silicon layer. Two simulated models are created: one with a sudden change in lattice constant (strained Si on a “fat” Si substrate) and another with a sudden change in atomic number (strained Si on a Cl substrate) in order to separate the effects of strain discontinuities from atomic number discontinuities measuring strain using Geometric Phase Analysis (GPA). The simulated models are subjected to image processing using GPA software developed by Chung. Two dimensional strain maps are reconstructed and the local strain is determined. Further, an analysis is done to evaluate the best imaging conditions for strain measurement using GPA at heteroepitaxial interfaces. In addition, the behavior of GPA across a step function in strain or atomic number is examined for information about (a) spatial resolution, (b) the effects of a sudden change in atomic number, (c) instrument parameters, and (d) specimen thickness for a 300KeV TEM. / text

Bakgrund: Styrkelyftare utsätter kroppen för stora belastningar. 70 % av utövarna har skador som hämmar vid träning. Rörelsekontrollen kan påverkas vid muskuloskeletala besvär, varför denna studie undersöker eventuell relation mellan rörelsekontroll och skada hos styrkelyftare. Syfte: Undersöka relationen mellan rörelsekontroll och skador hos styrkelyftare. Metod: 22 styrkelyftare utförde sex rörelsekontrolltester enligt JEMS samt deltog i en enkät gällande skador. Poängen på testerna dikotomiserades och beräknades i ett chi-tvåtest för att undersöka samband mellan testresultaten och skadorna. Ett Mann whitney-U test användes för att undersöka eventuella skillnader mellan skadade och icke skadade. Resultat: Signifikanta resultat kunde ses där styrkelyftare med skada i underkroppen uppvisade ett försämrat resultat i ”Sittande knälyft höger” (p=0,03) och ”Sittande knälyft vänster” (p=0,04). Det fanns även en signifikant skillnad mellan skadade och icke skadade på testet ”Sittande knälyft vänster” (p=0,034). Inga signifikanta resultat kunde ses i övriga tester. Konklusion: Trots signifikanta resultat går inte att dra några konkreta slutsatser gällande relationen mellan rörelsekontroll och skador hos styrkelyftare. Det behövs vidare studier som undersöker liknande rörelsekontrolltester men med ett betyande deltagarantal för att få en bättre power och för att kunna se några signifikanta resultat. <img src="file:///page3image24712" /> / Background: Powerlifters are exposed for heavy loads. 70 % of the lifters have injuries that limit during training. The movement control could be affected by musculoskeletal disorders, therefore this study examines the relationship between movement control and injuries. Purpose: Investigate the relationship between movement control and injuries among powerlifters. Method: 22 powerlifters performed six movement control tests according to JEMS and answered a questionnaire regarding injuries. The test score was dichotomized and analysed in a chi square test to investigate the relationship between movement control and injuries. A Mann Whitney U-test identified the differences between injuried and non-injuried powerlifters. Results: Significant results was seen in powerlifters with injury in the lower body, they showed an impaired result in ”Seated knee lift right” (p=0,03) and ”Seated knee lift left” (p=0,04). A significant differences was showed between the injuried and non-injuried in the test ”Seated knee lift left” (p=0,034). No significant results were seen in the other tests. Conclusion: Despite significant results it is not possible to conclude the relationship between movement control and injuries of powerlifters. Further studies are needed to investigate movement control tests, but with a higher amount of participants to see significant results.

Within the collaborative research center SFB 920 “Multifunctional Filters for Metal Melt Filtration”, the thermally induced formation of metastable aluminum oxides and related microstructural changes were investigated. It was confirmed that the γ-Al₂O₃ phase possesses a defective spinel structure containing Al vacancies that preserve the stoichiometry of this phase. The presence of vacancies fragments apparently the γ-Al₂O₃ crystallites into nanocrystalline domains, which are separated by non-conservative antiphase boundaries (APBs) of the type {100} ¼<110>. These APBs form a 3D network that is randomly distributed over all crystallographically equivalent lattice planes. This phenomenon causes a starlike (and hkl-dependent) broadening of the reciprocal lattice points that correspond to the aluminum sublattice. It was shown that the extent of the broadening of the reciprocal lattice points can be predicted by employing the phase shift factors. With increasing degree of the APBs ordering, the initial streaks representing the broadened reflections start to split, forming superstructure reflections. This superstructure of γ-Al₂O₃ is commonly known as δ-Al₂O₃. Between the ordered APBs, the crystal structure of δ-Al₂O₃ is closely related to the crystal structure of monoclinic θ-Al₂O₃. The phase transition of γ-Al₂O₃/δ-Al₂O₃ to θ-Al₂O₃ proceeds via migration of just three Al³⁺ cations to the neighboring tetrahedral and octahedral sites in the cubic close packed (ccp) oxygen sublattice. The general migration vector is ⅛<111> (γ-Al₂O₃). Diffraction effects associated with different intermediate states can be explained by an improper long-range ordering of equivalent APBs or certain Al³⁺ cations and the local formation of θ-Al₂O₃ within the δ-Al₂O₃ superstructure. The formation of θ-Al₂O₃ is accompanied by an increase of the occupancy of the tetrahedral sites in the oxygen sublattice by the Al³⁺ cations. In surrounding local γ-Al₂O₃ domains, however, some cations migrate from the tetrahedral to the octahedral sites. Thus, the local formation of θ-Al₂O₃ is nearly invisible for the ²⁷Al 1D magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. Still, it was recognized by the 2D multiple quantum (MQ) MAS NMR spectroscopy. A continuous formation of the θ-Al₂O₃ domains was confirmed by the Raman spectroscopy, X-ray diffraction (XRD) and selected area electron diffraction (SAED). The proposed microstructure and transformation models helped to explain the thermal stabilization of the metastable alumina phases by Si-doping. For investigation of the thermally induced phase transitions in metastable alumina phases, boehmite (γ-AlO(OH)) was chosen as the starting compound. However, the metastable alumina phases were also observed in endogenous inclusions present in solidified steel melts. For identification of these phases, a procedure for reconstruction of spherical Kikuchi maps from recorded EBSD patterns was developed.