On the efficiency of impingers with fritted nozzle tip for collection of ultrafine particles

The aim of this study was to determine the collection efficiency of ultrafine particles into an impinger fitted with a fritted nozzle tip as a means to increase contact surface area between the aerosol and the liquid. The influence of liquid sampling volume, frit porosity and the nature of the sampling liquid was explored and it was shown that all impact on the collection efficiency of particles smaller than 220 nm. Obtained values for overall collection efficiency were substantially higher (~30–95%) than have been previously reported, mainly due to the high deposition of particles in the fritted nozzle tip, especially in case of finer porosity frits and smaller particles. Values for the capture efficiency of the solvent alone ranged from 20 to 45%, depending on the type and the volume of solvent. Additionally, our results show that airstream dispersion into bubbles improves particle trapping by the liquid and that there is a difference in collection efficiencies based on the nature and volume of the solvent used.

The impact of unique characteristics of projects and project-based organisations on knowledge transfer

Knowledge has been recognised as an important organisational asset that increases in value when shared; the opposite to other organisational assets which decrease in value during their exploitation. Effective knowledge transfer in organisations helps to achieve and maintain competitive advantage and ultimately organisational success. So far, the research on knowledge transfer has focused on traditional (functional) organisations. Only recently has attention been directed towards knowledge transfer in projects. Existing research on project learning has recognised the need for knowledge transfer within and across projects in project-based organisations (PBOs). Most projects can provide valuable new knowledge from unexpected actions, approaches or problems experienced during the project phases. The aim of this paper is to demonstrate the impact of unique projects characteristics on knowledge transfer in PBO. This is accomplished through review of the literature and a series of interviews with senior project practitioners. The interviews complement the findings from the literature. Knowledge transfer in projects occurs by social communication and transfer of lessons learned where project management offices (PMOs) and project managers play significant roles in enhancing knowledge transfer and communication within the PBO and across projects. They act as connectors between projects and the PBO ‘hub’. Moreover, some project management processes naturally facilitate knowledge transfer across projects. On the other hand, PBOs face communication challenges due to unique and temporary characteristics of projects. The distance between projects and the lack or weakness of formal links across projects, create communication problems that impede knowledge transfer across projects. The main contribution of this paper is to demonstrate that both social communication and explicit informational channels play important role in inter-project knowledge transfer. Interviews also revealed the important role organisational culture play in knowledge transfer in PBOs.