Refine
Document Type
Way of publication
- Open Access (1)
Language
- English (23)
Keywords
- Electronic band structure (1)
- Epitaxy (1)
- GeSn (1)
- Heterostructures (1)
- Lasers (1)
- Nanowires (1)
- PLM (1)
- Photodetectors (1)
- Photonics (1)
- Plasmonics (1)
Institute
- FG Experimentalphysik und funktionale Materialien (9)
- FG Praktische Informatik / Graphische Systeme (3)
- FG Pädagogische Psychologie in Gesundheitsberufen (3)
- FG Technische Akustik (3)
- Zentrale Analytik der BTU Cottbus-Senftenberg (ZA-BTU) / Zentrales Analytisches Labor (2)
- FG Angewandte Physik und Halbleiterspektroskopie (1)
- FG Bodenschutz und Rekultivierung (1)
- FG Hydrologie (1)
- FG Schaltkreisentwurf (1)
BTU
Vanadium dioxide (VO2) features a pronounced, thermally-driven metal-to-insulator transition at 340 K. Employing epitaxial stress on rutile TiO2(001) substrates, the transition can be tuned to occur close to room temperature. Striving for applications in oxide-electronic devices, the lateral homogeneity of such samples must be considered as an important prerequisite for efforts towards miniaturization. Moreover, the preparation of smooth surfaces is crucial for vertically stacked devices and, hence, the design of functional interfaces. Here, the surface morphology of VO2/TiO2(001) films was analyzed by low-energy electron microscopy and diffraction as well as scanning probe microscopy. The formation of large terraces could be achieved under temperature-induced annealing, but also the occurrence of facets was observed and characterized. Further, we report on quasi-periodic arrangements of crack defects which evolve due to thermal stress under cooling. While these might impair some applicational endeavours, they may also present crystallographically well-oriented nano-templates of bulk-like properties for advanced approaches.
The integration of Ge on Si for photonics applications has reached a high level of maturity: Ge photodetectors are available on the Si platform in foundry processes, and Si/Ge heterostructure multiple quantum-well photodiodes are rapidly progressing toward applications in light modulation. These successes result from decades of development of high-quality material growth and integration, which, more recently, has sparked an increasingly broad field of photonic device research based on Si/Ge heterostructures that extends from quantum cascade lasers to sensors. Here, we highlight selected recent structure and device developments as well as possible future trends that are enabled by the maturity of the SiGe material platform
Measuring the Discernibility of Virtual Objects in Conventional and Stylized Augmented Reality
(2006)
Experimental Investigation of Tip Vortex Formation Noise Produced by Wall-Mounted Finite Airfoils
(2021)
Research on the development of bullying is often based upon Bronfenbrenner’s socioecological model (Swearer & Hymel, 2015). Thus, various relevant contextual variables have been identified, including classroom climate and school climate (Thornberg et al., 2018; Zych et al., 2019). School climate has been defined in different ways, mostly including relationships between people in the school environment (Wang et al., 2016). Empirically, only the relationships between students (also summarised within the class as classroom climate) and between teachers and pupils are usually considered. However, teachers have been identified as particularly significant in the bullying process and as role models for students (Colpin et al., 2021). Because of this, it is assumed that relationships among teachers can also be significant risk factors for student bullying. In this study, we investigate communication climate among teachers as part of the school climate and its associations to student bullying. In addition, we follow Bronfenbrenner’s idea of interactions among contextual levels by considering both school climate and classroom climate and investigating moderation effects. Data was collected from more than 550 teachers and 2,000 students in 114 classes at 24 schools in Germany. The analyses involved three-level hierarchical binary
regression analyses and cross-level interaction models. Findings suggest that staff communication climate is not associated directly with students’ experiences with bullying, but that the worse
staff communication climate, the more students bully others in classrooms with high rates of rivalry (cross-level moderation). The associations will further be analysed under consideration of relevant control variables. Final results will be presented at the conference. The study broadens the contextual perspective on bullying by including more than one level at once and supports the importance of a whole-school perspective on bullying.
Unintentional p-type conductivity in intrinsic Ge-rich SiGe/Ge heterostructures grown on Si(001)
(2023)
Direct-band-gap Germanium-Tin alloys (Ge1-xSnx) with high carrier mobilities are promising materials for nano- and optoelectronics. The concentration of open volume defects in the alloy, such as Sn and Ge vacancies, influences the final device performance. In this article, we present an evaluation of the point defects in molecular-beam-epitaxy grown Ge1-xSnx films treated by post-growth nanosecond-range pulsed laser melting (PLM). Doppler broadening – variable energy positron annihilation spectroscopy and variable energy positron annihilation lifetime spectroscopy are used to investigate the defect nanostructure in the Ge1-xSnx films exposed to increasing laser energy density. The experimental results, supported with ATomic SUPerposition calculations, evidence that after PLM, the average size of the open volume defects increases, which represents a raise in concentration of vacancy agglomerations, but the overall defect density is reduced as a function of the PLM fluence. At the same time, the positron annihilation spectroscopy analysis provides information about dislocations and Ge vacancies decorated by Sn atoms. Moreover, it is shown that the PLM reduces the strain in the layer, while dislocations are responsible for trapping of Sn and formation of small Sn-rich-clusters.
Introduction
Research on bullying prevention and intervention is very often conducted against the theoretical background of socio-ecological models (e.g., the socio-ecological diathesis-stress model; Swearer & Hymel, 2015). This leads to a special focus on different social contexts, without which the complexity of bullying processes cannot be understood. In recent years, the role of the teacher in the bullying process has received special attention in research (Colpin et al, 2021). The importance of the teacher's actions in reducing existing bullying or preventing further bullying has been highlighted in various works, and the need to include teachers in anti-bullying measures and to train them actively in bullying intervention behaviour is emphasised in meta-analyses (Gaffney et al., 2019, 2021; Van Verseveld et al., 2019). When it comes to concrete steps for teachers, many anti-bullying programmes also emphasise the involvement of parents, which in some countries also results from legal requirements. A meta-analysis showed that school-wide anti-bullying programs with a component of parental involvement can be successful in reducing bullying perpetration and victimization (Huang et al., 2019). Furthermore, the involvement of parents is also important against the background of socio-ecological theory models, as parents represent a significant socialisation context. Cooperation between home and school can influence the behaviour of students as an influence from the mesosystem. However, only a few studies go beyond the requirement of such cooperation, and also the information provided on parent components in anti-bullying programs are limited (Huang et al., 2019). The aim of the systematic review is to identify research findings that provide information on the effectiveness and nature of home-school cooperation in bullying prevention and intervention.
Method
The aim is to identify and analyse literature that looks at 1) both the school context and the family context and 2) the interaction of the two contexts in relation to bullying occurrence, bullying development, bullying prevention and bullying intervention. For this purpose, a systematic literature search is conducted in the databases Cochrane Library, EBSCO, PsycINFO, PubMed, Scopus, and Web of Science. In addition, a call for grey literature will be distributed in relevant networks (e.g., International Society for Research on Aggression, national psychological societies in Germany, Austria, England, and Norway). The search term has not yet been finalised, but will contain the terms "Bully*", "Parent* OR Home" and "School OR teacher", which will be connected by AND. Both qualitative and quantitative studies will be included with no restrictions on the publication period. Publications in English and German will be included (other languages cannot be included, as only one person in the research team speaks another language and thus no double coding can take place).
In the coming months, the research group will create and test a detailed coding manual specific for the research questions of the review. The quality assessment will be done through an established tool for qualitative and quantitative publications (e.g., Mixed Methods Appraisal Tool MMAT, Hong et al., 2018). The screening of titles, abstracts, and keywords according to inclusion and exclusion criteria as well as the full coding of the included publications will each be carried out by two persons. Interrater reliability will be calculated.
Results
Results are not yet available. We will be able to present the first results at the WABF. These will include, in particular, an overview of the identified relevant literature (e.g., number, information on publication types, sample size and country, result of quality assessment) and its research questions, as well as the summary of the identified results.
Conclusion
Through the systematic review, we will provide an up-to-date, comprehensive overview of the current state of the literature on parent-teacher collaboration in the context of bullying prevention and intervention. Detailed conclusions will be drawn from the initial findings, which can be presented at WABF.
Implications for research/practice
The comprehensive and up-to-date research review will identify research gaps and provide suggestions for future research on parent-teacher cooperation in the bullying context. By processing findings on the effect of the family and school developmental context on bullying processes when both contexts are considered simultaneously, implications for practice can also be expected. Previous findings call for collaboration between home and school in addressing bullying, and in some cases, as in the meta-analysis by Huang et al. (2019), depict its impact. However, details on the design of this cooperation, on hurdles and challenges, on legal frameworks and on aspects of cooperation that support a successful effect of cooperation are largely missing. By systematically compiling the findings to date, we provide not only academics but also practitioners with an up-to-date overview of the findings. This will enable practitioners to train teachers on collaborating with parents when incidents of bullying has occurred under consideration of recent scientific findings, supporting the practical usage of scientific findings.
Selected References
Colpin, H., Bauman, S. & Menesini, E. (2021). Teachers’ responses to bullying: Unravelling their consequences and antecedents: Introduction to the special issue. European Journal of Developmental Psychology, 18(6), 781-797.
Gaffney, H., Ttofi, M. M. & Farrington, D. P. (2019). Evaluating the effectiveness of school-bullying prevention programs: An updated meta-analytical review. Aggression and Violent Behavior, 45, 111–133.
Gaffney, H., Ttofi, M. M. & Farrington, D. P. (2021). What works in anti-bullying programs? Analysis of effective intervention components. Journal of School Psychology, 85, 37–56.
Hong, Q. N., Fàbregues, S., Bartlett, G., Boardman, F., Cargo, M., Dagenais, P., Gagnon, M.-P., Griffiths, F., Nicolau, B., O’Cathain, A., Rousseau, M.-C., & Vedel, I. (2018). Mixed Methods Appraisal Tool (MMAT) Version 2018. User Guide. Available under http://mixedmethodsappraisaltoolpublic.pbworks.com
Huang, Y., Espelage, D. L., Polanin, J. R., & Hong, J. S. (2019). A meta-analytic review of school-based anti-bullying programs with a parent component. International Journal of Bullying Prevention, 1, 32–44.
Swearer, S. M., & Hymel, S. (2015). Understanding the psychology of bullying. Moving toward a social-ecological diathesis-stress model. American Psychologist, 70(4), 344–353.
Van Verseveld, M. D. A., Fukkink, R. G., Fekkes, M. & Oostdam, R. J. (2019). Effects of antibullying programs on teachers’ interventions in bullying situations. A meta‐analysis. Psychology in the Schools, 56(9), 1522–1539.