2 resultados para Hoikkala, Tommi
em Digital Peer Publishing
Resumo:
This article discusses the impacts of globalization, neo-liberal social policies and the Finnish economic recession of the 1990s on children's and young people's welfare. It summarises some of the impacts of Finnish social policies on the everyday lives of families with children and highlights some of the features of the recent and current debates surrounding youth delinquency and the societal reactions to young generations. All this contributes to a contradictory and conflicting societal context which challenges experts in the field of child welfare social work experts to operate - as expected - at the right moment, legally and effectively. Instead of being overly-defensive for the ‘good old’ ways of practicing social work with children, the authors invite social work scholars and practitioners to reconceptualise both the concept of children's citizenship and its position both in child welfare theory and practice in the context of children's global rights.
Resumo:
An emergency lowering system for use in safety critical crane applications is discussed. The system is used to safely lower the payload of a crane in case of an electric blackout. The system is based on a backup power source, which is used to operate the crane while the regular supply is not available. The system enables both horizontal and vertical movements of the crane. Two different configurations for building the system are described, one with an uninterruptible power source (UPS) or a diesel generator connected in parallel to the crane’s power supply and one with a customized energy storage connected to the intermediate DC-link in the crane. In order to be able to size the backup power source, the power required during emergency lowering needs to be understood. A simulation model is used to study and optimize the power used during emergency lowering. The simulation model and optimizations are verified in a test hoist. Simulation results are presented with non-optimized and optimized controls for two example applications: a paper roll crane and a steel mill ladle crane. The optimizations are found to significantly reduce the required power for the crane movements during emergency lowering.