2 resultados para secondary xylem

em CORA - Cork Open Research Archive - University College Cork - Ireland


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Numerous laboratory experiments have been performed in an attempt to mimic atmospheric secondary organic aerosol (SOA) formation. However, it is still unclear how close the aerosol particles generated in laboratory experiments resemble atmospheric SOA with respect to their detailed chemical composition. In this study, we generated SOA in a simulation chamber from the ozonolysis of α-pinene and a biogenic volatile organic compound (BVOC) mixture containing α- and β-pinene, Δ3-carene, and isoprene. The detailed molecular composition of laboratory-generated SOA was compared with that of background ambient aerosol collected at a boreal forest site (Hyytiälä, Finland) and an urban location (Cork, Ireland) using direct infusion nanoelectrospray ultrahigh resolution mass spectrometry. Kendrick Mass Defect and Van Krevelen approaches were used to identify and compare compound classes and distributions of the detected species. The laboratory-generated SOA contained a distinguishable group of dimers that was not observed in the ambient samples. The presence of dimers was found to be less pronounced in the SOA from the VOC mixtures when compared to the one component precursor system. The elemental composition of the compounds identified in the monomeric region from the ozonolysis of both α-pinene and VOC mixtures represented the ambient organic composition of particles collected at the boreal forest site reasonably well, with about 70% of common molecular formulae. In contrast, large differences were found between the laboratory-generated BVOC samples and the ambient urban sample. To our knowledge this is the first direct comparison of molecular composition of laboratory-generated SOA from BVOC mixtures and ambient samples.

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This research interrogates the status of citizenship education in Irish secondary schools. The following questions are examined: How does school culture impact on citizenship education? What value is accorded to the subjects, Civic, Social and Political Education (CSPE) and Social, Personal and Health Education (SPHE)? To what extent are the subjects of both the cognitive and non-cognitive curricula affirmed? The importance of these factors in supporting the social, ethical, personal, political and emotional development of students is explored. The concept of citizenship is dynamic and constantly evolving in response to societal change. Society is increasingly concerned with issues such as: globalisation; cosmopolitanism; the threat of global risk; environment sustainability; socio-economic inequality; and recognition/misrecognition of new identities and group rights. The pedagogical philosophy of Paulo Freire which seeks to educate for the conscientisation and humanisation of the student is central to this research. Using a mixed methods approach, data on the insights of students, parents, teachers and school Principals was collected. In relation to Irish secondary school education, the study reached three main conclusions. (1) The educational stakeholders rate the subjects of the non-cognitive curriculum poorly. (2) The subjects Civic, Social and Political education (CSPE), and Social, Personal and Health Education (SPHE) command a low status in the secondary school setting. (3) The day-to-day school climate is influenced by an educational philosophy that is instrumentalist in character. Elements of school culture such as: the ethic of care; the informal curriculum; education for life after school; and affirmation of teachers, are not sufficiently prioritised in supporting education for citizenship. The research concludes that the approach to education for citizenship needs to be more robust within the overall curriculum, and culture and ethos of the Irish education system.