Although most papers in the field of sonochemical degradation of volatile organics in aqueous media describe experiments at the millimolar concentration range, this study focuses on the degradation kinetics of chlorobenzene (CB) and trichloroethylene (TCE) in the micromolar range. It was found that the reaction kinetics increase with decreasing initial substrate concentrations. For example, the pseudo-first-order reaction rate constant of CB increases by a factor of 14.3, if the initial concentration drops from 3440 to 1 microM. Previous work in the millimolar range has shown that the degradation of these volatiles is mainly due to pyrolytic reactions. The enhancement of the reaction kinetics at lower concentrations, in this work, could no longer be explained by this mechanism, even by taking into account the effect of the concentration of the solutes on the reaction temperature. Therefore, a new model was developed, incorporating gas phase OH radical induced degradation, next to pyrolysis. The model, fitting the experimental results, illustrated that at micromolar concentrations the OH radical induced degradation becomes significant. Simulations showed that at initial concentrations of CB > 1000 microM degradation is due to pyrolysis for over 99.97%, but it was also demonstrated that at concentrations between 1 and 5 microM, the OH radical mechanism contributed 48.5% of the total degradation.

Current literature suggests that community sport contributes to social cohesion. Yet, empirical research is still scant, and existing conceptualizations of social cohesion in the context of community sport are dominated by a social capital approach emphasizing the individual over the structural conditions that need to be addressed if social cohesion is to be achieved. This article aims to provide more insight into how social cohesion is operationalized in community sport practices. Qualitative research on the practical understandings of community sport practitioners was undertaken across three cities in Flanders, Belgium. The findings suggest that practitioners adopt both individual and structural understandings of social cohesion. Moreover, they experience that their efforts to develop a structural approach are pressured by a dominant individualized approach. These findings reveal a disjuncture between academic constructs of social cohesion and the practical understandings of community sport practitioners. The article proposes ways to address the need for the empirical and conceptual development of social cohesion in the context of community sport and the broader community development field.

Research has focused on the question if and how leisure can create social cohesion and can alleviate cultural segregation in divided community contexts.Community sport in particular is believed to create socio-cultural cohesiveness, as it aims at a sense of community, a task in which regular sports often seem to fail. However, the experiences of participants in relation to socio-cultural cohesiveness in community sport remain absent in the existing body of research.This article provides insights into those experiences, by drawing on a qualitative study in Flanders, Belgium. Based on the findings, we challenge the one-sided focus on socio-cultural cohesiveness to obtain a sense of community, as the perspectives of participants reveal that also political and economic dimensions of cohesion are relevant, next to socio-cultural dimensions. We argue that community cannot be reduced to socio-cultural cohesion, but should be understood from the intersection between cultural, economic and political dimensions of cohesion. Implications for practice, both in relation to community sport and the broader leisure field and further research are given.

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