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Effect of imaging conditions for reliable measurement of local strain from synthetic High Resolution Transmission Electron Microscope (HRTEM) images by Geometrical Phase Analysis (GPA)Rajagopalan, Srivaramangai 05 August 2010 (has links)
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
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Relationen mellan rörelsekontroll och skador hos styrkelyftare : - en tvärsnittsstudieLundström, Christoffer January 2016 (has links)
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.
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