70 research outputs found

    Qualitative doctoral research in educational settings: reflecting on meaningful encounters

    Get PDF
    In qualitative doctoral research the methodological approach, and the research design are extremely important when ensuring the rigorousness of the work. This is particularly significant for all researchers, and even more for doctoral students who are still developing their research and analytical skills. This paper aims to support doctoral students in their research journey by highlighting some of the tensions involved in conducting qualitative research by unpicking the experiences of two doctoral students to learn from the concerns, questions and reflections on the use of qualitative methodology in their doctoral research projects. The findings reveal challenges and insights with regards to reflection, educational research and the developing identity of being a researcher. The paper discusses these reflections to support and guide doctoral students as early career researchers when planning and conducting qualitative research in educational settings

    Exploring the origin of high optical absorption in conjugated polymers

    Get PDF
    The specific optical absorption of an organic semiconductor is critical to the performance of organic optoelectronic devices. For example, higher light-harvesting efficiency can lead to higher photocurrent in solar cells that are limited by sub-optimal electrical transport. Here, we compare over 40 conjugated polymers, and find that many different chemical structures share an apparent maximum in their extinction coefficients. However, a diketopyrrolopyrrole-thienothiophene copolymer shows remarkably high optical absorption at relatively low photon energies. By investigating its backbone structure and conformation with measurements and quantum chemical calculations, we find that the high optical absorption can be explained by the high persistence length of the polymer. Accordingly, we demonstrate high absorption in other polymers with high theoretical persistence length. Visible light harvesting may be enhanced in other conjugated polymers through judicious design of the structure

    Risk factors for death from invasive pneumococcal disease, europe, 2010

    Get PDF
    We studied the possible association between patient age and sex, clinical presentation, Streptococcus pneumoniae serotype, antimicrobial resistance, and death in invasive pneumococcal disease cases reported by 17 European countries during 2010. The study sample comprised 2,921 patients, of whom 56.8% were men and 38.2% were >65 years of age. Meningitis occurred in 18.5% of cases. Death was reported in 264 (9.0%) cases. Older age, meningitis, and nonsusceptibility to penicillin were signifcantly asso ciated with death. Non-pneumococcal conjugate vaccine (PCV) serotypes among children 65 years of age, risk did not differ by serotype. These fndings highlight differences in case-fatality rates between sero types and age; thus, continued epidemiologic surveillance across all ages is crucial to monitor the long-term effects of PCVs
    corecore